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Sample records for surface mre drivers

  1. Surface association and the MreB cytoskeleton regulate pilus production, localization and function in Pseudomonas aeruginosa.

    Science.gov (United States)

    Cowles, Kimberly N; Gitai, Zemer

    2010-06-01

    Spatial organization of bacterial proteins influences many cellular processes, including division, chromosome segregation and motility. Virulence-associated proteins also localize to specific destinations within bacterial cells. However, the functions and mechanisms of virulence factor localization remain largely unknown. In this work, we demonstrate that polar assembly of the Pseudomonas aeruginosa PAO1 type IV pilus is regulated by surface association in a manner that affects gene transcription, protein levels and protein localization. We also uncover one mechanism for this regulation that acts through the actin homologue MreB. Inactivation of MreB leads to mislocalization of the pilus retraction ATPase PilT, mislocalization of the pili themselves and a reduction in motility. Furthermore, the role of MreB in polar localization of PilT is modulated by surface association, corroborating our results that environmental factors influence the regulation of pilus production. Specifically, MreB mediates both the initiation and maintenance of PilT localization when cells are grown in suspension but only affects the initiation of localization when cells are grown on a surface. Together, these results suggest that the bacterial cytoskeleton provides a mechanism for the polar localization of P. aeruginosa pili and demonstrate that protein localization may represent an important aspect of virulence factor regulation in bacterial pathogens.

  2. Dysfunctional MreB inhibits chromosome segregation in Escherichia coli

    DEFF Research Database (Denmark)

    Kruse, Thomas; Møller-Jensen, Jakob; Løbner-Olesen, Anders

    2003-01-01

    The mechanism of prokaryotic chromosome segregation is not known. MreB, an actin homolog, is a shape-determining factor in rod-shaped prokaryotic cells. Using immunofluorescence microscopy we found that MreB of Escherichia coli formed helical filaments located beneath the cell surface. Flow...... cytometric and cytological analyses indicated that MreB-depleted cells segregated their chromosomes in pairs, consistent with chromosome cohesion. Overexpression of wild-type MreB inhibited cell division but did not perturb chromosome segregation. Overexpression of mutant forms of MreB inhibited cell...... that MreB filaments participate in directional chromosome movement and segregation....

  3. The morphogenetic MreBCD proteins of Escherichia coli form an essential membrane-bound complex

    DEFF Research Database (Denmark)

    Kruse, Thomas; Bork-Jensen, Jette; Gerdes, Kenn

    2005-01-01

    MreB proteins of Escherichia coli, Bacillus subtilis and Caulobacter crescentus form actin-like cables lying beneath the cell surface. The cables are required to guide longitudinal cell wall synthesis and their absence leads to merodiploid spherical and inflated cells prone to cell lysis. In B...... carrying the ftsQAZ genes suppressed the lethality of deletions in the mre operon. Using GFP and cell fractionation methods, we showed that the MreC and MreD proteins were associated with the cell membrane. Using a bacterial two-hybrid system, we found that MreC interacted with both MreB and Mre....... subtilis and C. crescentus, the mreB gene is essential. However, in E. coli, mreB was inferred not to be essential. Using a tight, conditional gene depletion system, we systematically investigated whether the E. coli mreBCD-encoded components were essential. We found that cells depleted of mreBCD became...

  4. A Caulobacter MreB mutant with irregular cell shape exhibits compensatory widening to maintain a preferred surface area to volume ratio

    Science.gov (United States)

    Harris, Leigh K.; Dye, Natalie A.; Theriot, Julie A.

    2014-01-01

    Summary Rod-shaped bacteria typically elongate at a uniform width. To investigate the genetic and physiological determinants involved in this process, we studied a mutation in the morphogenetic protein MreB in Caulobacter crescentus that gives rise to cells with a variable-width phenotype, where cells have regions that are both thinner and wider than wild-type. During growth, individual cells develop a balance of wide and thin regions, and mutant MreB dynamically localizes to poles and thin regions. Surprisingly, the surface area to volume ratio of these irregularly-shaped cells is, on average, very similar to wild-type. We propose that, while mutant MreB localizes to thin regions and promotes rod-like growth there, wide regions develop as a compensatory mechanism, allowing cells to maintain a wild-type-like surface area to volume ratio. To support this model, we have shown that cell widening is abrogated in growth conditions that promote higher surface area to volume ratios, and we have observed individual cells with high ratios return to wild-type levels over several hours by developing wide regions, suggesting that compensation can take place at the level of individual cells. PMID:25266768

  5. Lipid-linked cell wall precursors regulate membrane association of bacterial actin MreB

    OpenAIRE

    Schirner, Kathrin; Eun, Ye-Jin; Dion, Mike; Luo, Yun; Helmann, John D.; Garner, Ethan C.; Walker, Suzanne

    2014-01-01

    Summary The bacterial actin homolog MreB, which is critical for rod shape determination, forms filaments that rotate around the cell width on the inner surface of the cytoplasmic membrane. What determines filament association with the membranes or with other cell wall elongation proteins is not known. Using specific chemical and genetic perturbations while following MreB filament motion, we find that MreB membrane association is an actively regulated process that depends on the presence of li...

  6. Bacillus subtilis MreB orthologs self-organize into filamentous structures underneath the cell membrane in a heterologous cell system.

    Directory of Open Access Journals (Sweden)

    Felix Dempwolff

    Full Text Available Actin-like bacterial cytoskeletal element MreB has been shown to be essential for the maintenance of rod cell shape in many bacteria. MreB forms rapidly remodelling helical filaments underneath the cell membrane in Bacillus subtilis and in other bacterial cells, and co-localizes with its two paralogs, Mbl and MreBH. We show that MreB localizes as dynamic bundles of filaments underneath the cell membrane in Drosophila S2 Schneider cells, which become highly stable when the ATPase motif in MreB is modified. In agreement with ATP-dependent filament formation, the depletion of ATP in the cells lead to rapid dissociation of MreB filaments. Extended induction of MreB resulted in the formation of membrane protrusions, showing that like actin, MreB can exert force against the cell membrane. Mbl also formed membrane associated filaments, while MreBH formed filaments within the cytosol. When co-expressed, MreB, Mbl and MreBH built up mixed filaments underneath the cell membrane. Membrane protein RodZ localized to endosomes in S2 cells, but localized to the cell membrane when co-expressed with Mbl, showing that bacterial MreB/Mbl structures can recruit a protein to the cell membrane. Thus, MreB paralogs form a self-organizing and dynamic filamentous scaffold underneath the membrane that is able to recruit other proteins to the cell surface.

  7. Bacillus subtilis MreB orthologs self-organize into filamentous structures underneath the cell membrane in a heterologous cell system.

    Science.gov (United States)

    Dempwolff, Felix; Reimold, Christian; Reth, Michael; Graumann, Peter L

    2011-01-01

    Actin-like bacterial cytoskeletal element MreB has been shown to be essential for the maintenance of rod cell shape in many bacteria. MreB forms rapidly remodelling helical filaments underneath the cell membrane in Bacillus subtilis and in other bacterial cells, and co-localizes with its two paralogs, Mbl and MreBH. We show that MreB localizes as dynamic bundles of filaments underneath the cell membrane in Drosophila S2 Schneider cells, which become highly stable when the ATPase motif in MreB is modified. In agreement with ATP-dependent filament formation, the depletion of ATP in the cells lead to rapid dissociation of MreB filaments. Extended induction of MreB resulted in the formation of membrane protrusions, showing that like actin, MreB can exert force against the cell membrane. Mbl also formed membrane associated filaments, while MreBH formed filaments within the cytosol. When co-expressed, MreB, Mbl and MreBH built up mixed filaments underneath the cell membrane. Membrane protein RodZ localized to endosomes in S2 cells, but localized to the cell membrane when co-expressed with Mbl, showing that bacterial MreB/Mbl structures can recruit a protein to the cell membrane. Thus, MreB paralogs form a self-organizing and dynamic filamentous scaffold underneath the membrane that is able to recruit other proteins to the cell surface.

  8. MreC and MreD Proteins Are Not Required for Growth of Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Andreia C Tavares

    Full Text Available The transmembrane proteins MreC and MreD are present in a wide variety of bacteria and are thought to be involved in cell shape determination. Together with the actin homologue MreB and other morphological elements, they play an essential role in the synthesis of the lateral cell wall in rod-shaped bacteria. In ovococcus, which lack MreB homologues, mreCD are also essential and have been implicated in peripheral cell wall synthesis. In this work we addressed the possible roles of MreC and MreD in the spherical pathogen Staphylococcus aureus. We show that MreC and MreD are not essential for cell viability and do not seem to affect cell morphology, cell volume or cell cycle control. MreC and MreD localize preferentially to the division septa, but do not appear to influence peptidoglycan composition, nor the susceptibility to different antibiotics and to oxidative and osmotic stress agents. Our results suggest that the function of MreCD in S. aureus is not critical for cell division and cell shape determination.

  9. Purification and characterization of Escherichia coli MreB protein.

    Science.gov (United States)

    Nurse, Pearl; Marians, Kenneth J

    2013-02-01

    The actin homolog MreB is required in rod-shaped bacteria for maintenance of cell shape and is intimately connected to the holoenzyme that synthesizes the peptidoglycan layer. The protein has been reported variously to exist in helical loops under the cell surface, to rotate, and to move in patches in both directions around the cell surface. Studies of the Escherichia coli protein in vitro have been hampered by its tendency to aggregate. Here we report the purification and characterization of native E. coli MreB. The protein requires ATP hydrolysis for polymerization, forms bundles with a left-hand twist that can be as long as 4 μm, forms sheets in the presence of calcium, and has a critical concentration for polymerization of 1.5 μM.

  10. Purification and Characterization of Escherichia coli MreB Protein*

    Science.gov (United States)

    Nurse, Pearl; Marians, Kenneth J.

    2013-01-01

    The actin homolog MreB is required in rod-shaped bacteria for maintenance of cell shape and is intimately connected to the holoenzyme that synthesizes the peptidoglycan layer. The protein has been reported variously to exist in helical loops under the cell surface, to rotate, and to move in patches in both directions around the cell surface. Studies of the Escherichia coli protein in vitro have been hampered by its tendency to aggregate. Here we report the purification and characterization of native E. coli MreB. The protein requires ATP hydrolysis for polymerization, forms bundles with a left-hand twist that can be as long as 4 μm, forms sheets in the presence of calcium, and has a critical concentration for polymerization of 1.5 μm. PMID:23235161

  11. Presence of multiple sites containing polar material in spherical Escherichia coli cells that lack MreB.

    Science.gov (United States)

    Nilsen, Trine; Yan, Arthur W; Gale, Gregory; Goldberg, Marcia B

    2005-09-01

    In rod-shaped bacteria, certain proteins are specifically localized to the cell poles. The nature of the positional information that leads to the proper localization of these proteins is unclear. In a screen for factors required for the localization of the Shigella sp. actin assembly protein IcsA to the bacterial pole, a mutant carrying a transposon insertion in mreB displayed altered targeting of IcsA. The phenotype of cells containing a transposon insertion in mreB was indistinguishable from that of cells containing a nonpolar mutation in mreB or that of wild-type cells treated with the MreB inhibitor A22. In cells lacking MreB, a green fluorescent protein (GFP) fusion to a cytoplasmic derivative of IcsA localized to multiple sites. Secreted full-length native IcsA was present in multiple faint patches on the surfaces of these cells in a pattern similar to that seen for the cytoplasmic IcsA-GFP fusion. EpsM, the polar Vibrio cholerae inner membrane protein, also localized to multiple sites in mreB cells and colocalized with IcsA, indicating that localization to multiple sites is not unique to IcsA. Our results are consistent with the requirement, either direct or indirect, for MreB in the restriction of certain polar material to defined sites within the cell and, in the absence of MreB, with the formation of ectopic sites containing polar material.

  12. Lipid-linked cell wall precursors regulate membrane association of bacterial actin MreB.

    Science.gov (United States)

    Schirner, Kathrin; Eun, Ye-Jin; Dion, Mike; Luo, Yun; Helmann, John D; Garner, Ethan C; Walker, Suzanne

    2015-01-01

    The bacterial actin homolog MreB, which is crucial for rod shape determination, forms filaments that rotate around the cell width on the inner surface of the cytoplasmic membrane. What determines filament association with the membranes or with other cell wall elongation proteins is not known. Using specific chemical and genetic perturbations while following MreB filament motion, we find that MreB membrane association is an actively regulated process that depends on the presence of lipid-linked peptidoglycan precursors. When precursors are depleted, MreB filaments disassemble into the cytoplasm, and peptidoglycan synthesis becomes disorganized. In cells that lack wall teichoic acids but continue to make peptidoglycan, dynamic MreB filaments are observed, although their presence is not sufficient to establish a rod shape. We propose that the cell regulates MreB filament association with the membrane, allowing rapid and reversible inactivation of cell wall enzyme complexes in response to the inhibition of cell wall synthesis.

  13. Mutations in the nucleotide binding pocket of MreB can alter cell curvature and polar morphology in Caulobacter.

    Science.gov (United States)

    Dye, Natalie A; Pincus, Zachary; Fisher, Isabelle C; Shapiro, Lucy; Theriot, Julie A

    2011-07-01

    The maintenance of cell shape in Caulobacter crescentus requires the essential gene mreB, which encodes a member of the actin superfamily and the target of the antibiotic, A22. We isolated 35 unique A22-resistant Caulobacter strains with single amino acid substitutions near the nucleotide binding site of MreB. Mutations that alter cell curvature and mislocalize the intermediate filament crescentin cluster on the back surface of MreB's structure. Another subset have variable cell widths, with wide cell bodies and actively growing thin extensions of the cell poles that concentrate fluorescent MreB. We found that the extent to which MreB localization is perturbed is linearly correlated with the development of pointed cell poles and variable cell widths. Further, we find that a mutation to glycine of two conserved aspartic acid residues that are important for nucleotide hydrolysis in other members of the actin superfamily abolishes robust midcell recruitment of MreB but supports a normal rate of growth. These mutant strains provide novel insight into how MreB's protein structure, subcellular localization, and activity contribute to its function in bacterial cell shape. © 2011 Blackwell Publishing Ltd.

  14. Partial functional redundancy of MreB isoforms, MreB, Mbl and MreBH, in cell morphogenesis of Bacillus subtilis.

    Science.gov (United States)

    Kawai, Yoshikazu; Asai, Kei; Errington, Jeffery

    2009-08-01

    MreB proteins are bacterial actin homologues thought to have a role in cell shape determination by positioning the cell wall synthetic machinery. Many bacteria, particularly Gram-positives, have more than one MreB isoform. Bacillus subtilis has three, MreB, Mbl and MreBH, which colocalize in a single helical structure. We now show that the helical pattern of peptidoglycan (PG) synthesis in the cylindrical part of the rod-shaped cell is governed by the redundant action of the three MreB isoforms. Single mutants for any one of mreB isoforms can still incorporate PG in a helical pattern and generate a rod shape. However, after depletion of MreB in an mbl mutant (or depletion of all three isoforms) lateral wall PG synthesis was impaired and the cells became spherical and lytic. Overexpression of any one of the MreB isoforms overcame the lethality as well as the defects in lateral PG synthesis and cell shape. Furthermore, MreB and Mbl can associate with the peptidoglycan biosynthetic machinery independently. However, no single MreB isoform was able to support normal growth under various stress conditions, suggesting that the multiple isoforms are used to allow cells to maintain proper growth and morphogenesis under changing and sometimes adverse conditions.

  15. Driver`s behavior and the motion of motorized wheelchair when driving over rough surfaces; Dansa nado fuseichi sokoji no dendo kurumaisu no undo to join no kyodo

    Energy Technology Data Exchange (ETDEWEB)

    Enomoto, A; Yokomori, M; Yamaguchi, S [Meijo University, Aichi (Japan)

    1997-10-01

    We analyzed about the motion of motorized wheelchairs and the driver`s behavior when passing over the small obstacles in place of the rough surface road or the gateway of house and road by experiment. The tested two type wheelchairs are the front wheel drive and the rear wheel drive. The lean angle of head and the pulse rate of driver, the feeling for stability and the yaw angle and the roll angle of the wheelchair bodies, and the deflection angle of front wheels of rear drive. 4 refs., 11 figs., 1 tab.

  16. Assessing Resource Assessment for MRE (Invited)

    Science.gov (United States)

    Hanson, H. P.; Bozec, A.; Duerr, A. S.; Rauchenstein, L. T.

    2010-12-01

    The Southeast National Marine Renewable Energy Center at Florida Atlantic University is concerned with marine renewable energy (MRE) recovery from the Florida Current using marine hydrokinetic technology and, in the future, from the thermocline in the Florida Straits via ocean thermal energy conversion. Although neither concept is new, technology improvements and the evolution of policy now warrant optimism for the future of these potentially rich resources. In moving toward commercial-scale deployments of energy-generating systems, an important first step is accurate and unembellished assessment of the resource itself. In short, we must ask: how much energy might be available? The answer to this deceptively simple question depends, of course, on the technology itself - system efficiencies, for example - but it also depends on a variety of other limiting factors such as deployment strategies, environmental considerations, and the overall economics of MRE in the context of competing energy resources. While it is universally agreed that MRE development must occur within a framework of environmental stewardship, it is nonetheless inevitable that there will be trade-offs between absolute environmental protection and realizing the benefits of MRE implementation. As with solar-energy and wind-power technologies, MRE technologies interact with the environment in which they are deployed. Ecological, societal, and even physical resource concerns all require investigation and, in some cases, mitigation. Moreover, the converse - how will the environment affect the equipment? - presents technical challenges that have confounded the seagoing community forever. Biofouling, for example, will affect system efficiency and create significant maintenance and operations issues. Because this will also affect the economics of MRE, nonlinear interactions among the limiting factors complicate the overall issue of resource assessment significantly. While MRE technology development is

  17. Modeling driver stop/run behavior at the onset of a yellow indication considering driver run tendency and roadway surface conditions.

    Science.gov (United States)

    Elhenawy, Mohammed; Jahangiri, Arash; Rakha, Hesham A; El-Shawarby, Ihab

    2015-10-01

    The ability to model driver stop/run behavior at signalized intersections considering the roadway surface condition is critical in the design of advanced driver assistance systems. Such systems can reduce intersection crashes and fatalities by predicting driver stop/run behavior. The research presented in this paper uses data collected from two controlled field experiments on the Smart Road at the Virginia Tech Transportation Institute (VTTI) to model driver stop/run behavior at the onset of a yellow indication for different roadway surface conditions. The paper offers two contributions. First, it introduces a new predictor related to driver aggressiveness and demonstrates that this measure enhances the modeling of driver stop/run behavior. Second, it applies well-known artificial intelligence techniques including: adaptive boosting (AdaBoost), random forest, and support vector machine (SVM) algorithms as well as traditional logistic regression techniques on the data in order to develop a model that can be used by traffic signal controllers to predict driver stop/run decisions in a connected vehicle environment. The research demonstrates that by adding the proposed driver aggressiveness predictor to the model, there is a statistically significant increase in the model accuracy. Moreover the false alarm rate is significantly reduced but this reduction is not statistically significant. The study demonstrates that, for the subject data, the SVM machine learning algorithm performs the best in terms of optimum classification accuracy and false positive rates. However, the SVM model produces the best performance in terms of the classification accuracy only. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. The cell shape proteins MreB and MreC control cell morphogenesis by positioning cell wall synthetic complexes.

    Science.gov (United States)

    Divakaruni, Arun V; Baida, Cyril; White, Courtney L; Gober, James W

    2007-10-01

    MreB, the bacterial actin homologue, is thought to function in spatially co-ordinating cell morphogenesis in conjunction with MreC, a protein that wraps around the outside of the cell within the periplasmic space. In Caulobacter crescentus, MreC physically associates with penicillin-binding proteins (PBPs) which catalyse the insertion of intracellularly synthesized precursors into the peptidoglycan cell wall. Here we show that MreC is required for the spatial organization of components of the peptidoglycan-synthesizing holoenzyme in the periplasm and MreB directs the localization of a peptidoglycan precursor synthesis protein in the cytosol. Additionally, fluorescent vancomycin (Van-FL) labelling revealed that the bacterial cytoskeletal proteins MreB and FtsZ, as well as MreC and RodA, were required for peptidoglycan synthetic activity. MreB and FtsZ were found to be required for morphogenesis of the polar stalk. FtsZ was required for a cell cycle-regulated burst of peptidoglycan synthesis early in the cell cycle resulting in the synthesis of cross-band structures, whereas MreB was required for lengthening of the stalk. Thus, the bacterial cytoskeleton and cell shape-determining proteins such as MreC, function in concert to orchestrate the localization of cell wall synthetic complexes resulting in spatially co-ordinated and efficient peptidoglycan synthetic activity.

  19. MreB: pilot or passenger of cell wall synthesis?

    Science.gov (United States)

    White, Courtney L; Gober, James W

    2012-02-01

    The discovery that the bacterial cell shape determinant MreB is related to actin spurred new insights into bacterial morphogenesis and development. The trafficking and mechanical roles of the eukaryotic cytoskeleton were hypothesized to have a functional ancestor in MreB based on evidence implicating MreB as an organizer of cell wall synthesis. Genetic, biochemical and cytological studies implicate MreB as a coordinator of a large multi-protein peptidoglycan (PG) synthesizing holoenzyme. Recent advances in microscopy and new biochemical evidence, however, suggest that MreB may function differently than previously envisioned. This review summarizes our evolving knowledge of MreB and attempts to refine the generalized model of the proteins organizing PG synthesis in bacteria. This is generally thought to be conserved among eubacteria and the majority of the discussion will focus on studies from a few well-studied model organisms. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Processive motions of MreB micro-filaments coordinate cell wall growth

    Science.gov (United States)

    Garner, Ethan

    2012-02-01

    Rod-shaped bacteria elongate by the action of cell-wall synthesis complexes linked to underlying dynamic MreB filaments, but how these proteins function to allow continued elongation as a rod remains unknown. To understand how the movement of these filaments relates to cell wall synthesis, we characterized the dynamics of MreB and the cell wall elongation machinery using high-resolution particle tracking in Bacillus subtilis. We found that both MreB and the elongation machinery move in linear paths across the cell, moving at similar rates (˜20nm / second) and angles to the cell body, suggesting they function as single complexes. These proteins move circumferentially around the cell, principally perpendicular to its length. We find that the motions of these complexes are independent, as they can pause and reverse,and also as nearby complexes move independently in both directions across one surface of the cell. Inhibition of cell wall synthesis with antibiotics or depletions in the cell wall synthesis machinery blocked MreB movement, suggesting that the cell wall synthetic machinery is the motor in this system. We propose that bacteria elongate by the uncoordinated, circumferential movements of synthetic complexes that span the plasma membrane and insert radial hoops of new peptidoglycan during their transit.

  1. RodZ links MreB to cell wall synthesis to mediate MreB rotation and robust morphogenesis.

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    Morgenstein, Randy M; Bratton, Benjamin P; Nguyen, Jeffrey P; Ouzounov, Nikolay; Shaevitz, Joshua W; Gitai, Zemer

    2015-10-06

    The rod shape of most bacteria requires the actin homolog, MreB. Whereas MreB was initially thought to statically define rod shape, recent studies found that MreB dynamically rotates around the cell circumference dependent on cell wall synthesis. However, the mechanism by which cytoplasmic MreB is linked to extracytoplasmic cell wall synthesis and the function of this linkage for morphogenesis has remained unclear. Here we demonstrate that the transmembrane protein RodZ mediates MreB rotation by directly or indirectly coupling MreB to cell wall synthesis enzymes. Furthermore, we map the RodZ domains that link MreB to cell wall synthesis and identify mreB mutants that suppress the shape defect of ΔrodZ without restoring rotation, uncoupling rotation from rod-like growth. Surprisingly, MreB rotation is dispensable for rod-like shape determination under standard laboratory conditions but is required for the robustness of rod shape and growth under conditions of cell wall stress.

  2. A magnesium-dependent mreB null mutant: implications for the role of mreB in Bacillus subtilis.

    Science.gov (United States)

    Formstone, Alex; Errington, Jeffery

    2005-03-01

    MreB shares a common prokaryotic ancestor with actin and is present in almost all rod-shaped bacteria. MreB proteins have been implicated in a range of important cell processes, including cell morphogenesis, chromosome segregation and cell polarity. The mreB gene frequently lies at the beginning of a cluster of genes, immediately upstream of the conserved mreC and mreD genes. RNA analysis showed that in Bacillus subtilis mreB is co-transcribed with mreC and that these genes form part of an operon under the control of a promoter(s) upstream of mreB. Construction of an in-frame deletion of mreB and its complementation by mreB(+) only, in trans, established that the gene is important for maintenance of cell width and cell viability under normal growth conditions, independent of polar effects on downstream genes. Remarkably, virtually normal growth was restored to the mreB null mutant in the presence of high concentrations of magnesium, especially when high concentrations of the osmoprotectant, sucrose were also present. Under these conditions, cells could be maintained in the complete absence of an mreB gene, with almost normal morphology. No detectable effect on chromosome segregation was evident in the mutant, nor was there an effect on the topology of nascent peptidoglycan insertion. A GFP-MreB fusion was used to look at the localization of MreB in live cells. The pattern of localization was similar to that previously described, but no tight linkage to nucleoid positioning was evident. Propagation of the mreB null mutant in the absence of magnesium and sucrose led to a progressive increase in cell width, culminating in cell lysis. Cell division was also perturbed but this effect may be secondary to the disturbance in cell width. These results suggest that the major role of MreB in B. subtilis lies in the control of cell diameter.

  3. Assembly properties of the Bacillus subtilis actin, MreB.

    Science.gov (United States)

    Mayer, Joshua A; Amann, Kurt J

    2009-02-01

    The bacterial actin MreB has been implicated in a variety of cellular roles including cell shape determination, cell wall synthesis, chromosome condensation and segregation, and the establishment and maintenance of cell polarity. Toward elucidating a clearer understanding of how MreB functions inside the bacterial cell, we investigated biochemically the polymerization of MreB from Bacillus subtilis. Light scattering and sedimentation assays revealed pH-, ionic-, cationic-, and temperature-dependent behavior. B. subtilis MreB polymerizes in the presence of millimolar divalent cations in a protein concentration-dependent manner. Polymerization is favored by decreasing pH and inhibited by monovalent salts and low temperatures. Although B. subtilis MreB binds and hydrolyzes both ATP and GTP, it does not require a bound nucleotide for assembly and polymerizes indistinguishably regardless of the nucleotide species bound, with a critical concentration of approximately 900 nM. A number of the presently reported properties of B. subtilis MreB differ significantly from those of T. maritima MreB1 (Bean and Amann [2008]: Biochemistry 47: 826-835), including the nucleotide requirements and temperature and ionic effects on polymerization state. These observations collectively suggest that additional factors interact with MreB to account for its complex dynamic behavior in cells.

  4. Positioning cell wall synthetic complexes by the bacterial morphogenetic proteins MreB and MreD.

    Science.gov (United States)

    White, Courtney L; Kitich, Aleksandar; Gober, James W

    2010-05-01

    In Caulobacter crescentus, intact cables of the actin homologue, MreB, are required for the proper spatial positioning of MurG which catalyses the final step in peptidoglycan precursor synthesis. Similarly, in the periplasm, MreC controls the spatial orientation of the penicillin binding proteins and a lytic transglycosylase. We have now found that MreB cables are required for the organization of several other cytosolic murein biosynthetic enzymes such as MraY, MurB, MurC, MurE and MurF. We also show these proteins adopt a subcellular pattern of localization comparable to MurG, suggesting the existence of cytoskeletal-dependent interactions. Through extensive two-hybrid analyses, we have now generated a comprehensive interaction map of components of the bacterial morphogenetic complex. In the cytosol, this complex contains both murein biosynthetic enzymes and morphogenetic proteins, including RodA, RodZ and MreD. We show that the integral membrane protein, MreD, is essential for lateral peptidoglycan synthesis, interacts with the precursor synthesizing enzymes MurG and MraY, and additionally, determines MreB localization. Our results suggest that the interdependent localization of MreB and MreD functions to spatially organize a complex of peptidoglycan precursor synthesis proteins, which is required for propagation of a uniform cell shape and catalytically efficient peptidoglycan synthesis.

  5. Bacterial actin MreB forms antiparallel double filaments.

    Science.gov (United States)

    van den Ent, Fusinita; Izoré, Thierry; Bharat, Tanmay Am; Johnson, Christopher M; Löwe, Jan

    2014-05-02

    Filaments of all actin-like proteins known to date are assembled from pairs of protofilaments that are arranged in a parallel fashion, generating polarity. In this study, we show that the prokaryotic actin homologue MreB forms pairs of protofilaments that adopt an antiparallel arrangement in vitro and in vivo. We provide an atomic view of antiparallel protofilaments of Caulobacter MreB as apparent from crystal structures. We show that a protofilament doublet is essential for MreB's function in cell shape maintenance and demonstrate by in vivo site-specific cross-linking the antiparallel orientation of MreB protofilaments in E. coli. 3D cryo-EM shows that pairs of protofilaments of Caulobacter MreB tightly bind to membranes. Crystal structures of different nucleotide and polymerisation states of Caulobacter MreB reveal conserved conformational changes accompanying antiparallel filament formation. Finally, the antimicrobial agents A22/MP265 are shown to bind close to the bound nucleotide of MreB, presumably preventing nucleotide hydrolysis and destabilising double protofilaments.DOI: http://dx.doi.org/10.7554/eLife.02634.001. Copyright © 2014, van den Ent et al.

  6. Filament structure, organization, and dynamics in MreB sheets.

    Science.gov (United States)

    Popp, David; Narita, Akihiro; Maeda, Kayo; Fujisawa, Tetsuro; Ghoshdastider, Umesh; Iwasa, Mitsusada; Maéda, Yuichiro; Robinson, Robert C

    2010-05-21

    In vivo fluorescence microscopy studies of bacterial cells have shown that the bacterial shape-determining protein and actin homolog, MreB, forms cable-like structures that spiral around the periphery of the cell. The molecular structure of these cables has yet to be established. Here we show by electron microscopy that Thermatoga maritime MreB forms complex, several mum long multilayered sheets consisting of diagonally interwoven filaments in the presence of either ATP or GTP. This architecture, in agreement with recent rheological measurements on MreB cables, may have superior mechanical properties and could be an important feature for maintaining bacterial cell shape. MreB polymers within the sheets appear to be single-stranded helical filaments rather than the linear protofilaments found in the MreB crystal structure. Sheet assembly occurs over a wide range of pH, ionic strength, and temperature. Polymerization kinetics are consistent with a cooperative assembly mechanism requiring only two steps: monomer activation followed by elongation. Steady-state TIRF microscopy studies of MreB suggest filament treadmilling while high pressure small angle x-ray scattering measurements indicate that the stability of MreB polymers is similar to that of F-actin filaments. In the presence of ADP or GDP, long, thin cables formed in which MreB was arranged in parallel as linear protofilaments. This suggests that the bacterial cell may exploit various nucleotides to generate different filament structures within cables for specific MreB-based functions.

  7. The sign, magnitude and potential drivers of change in surface water extent in Canadian tundra

    Science.gov (United States)

    Carroll, Mark L.; Loboda, Tatiana V.

    2018-04-01

    The accelerated rate of warming in the Arctic has considerable implications for all components of ecosystem functioning in the High Northern Latitudes. Changes to hydrological cycle in the Arctic are particularly complex as the observed and projected warming directly impacts permafrost and leads to variable responses in surface water extent which is currently poorly characterized at the regional scale. In this study we take advantage of the 30 plus years of medium resolution (30 m) Landsat data to quantify the spatial patterns of change in the extent of water bodies in the Arctic tundra in Nunavut, Canada. Our results show a divergent pattern of change—growing surface water extent in the north-west and shrinking in the south-east—which is not a function of the overall distribution of surface water in the region. The observed changes cannot be explained by latitudinal stratification, nor is it explained by available temperature and precipitation records. However, the sign of change appears to be consistent within the boundaries of individual watersheds defined by the Canada National Hydro Network based on the random forest analysis. Using land cover maps as a proxy for ecological function we were able to link shrinking tundra water bodies to substrates with shallow soil layers (i.e. bedrock and barren landscapes) with a moderate correlation (R 2 = 0.46, p evaporation as an important driver of surface water decrease in these cases.

  8. MreB and MurG as scaffolds for the cytoplasmic steps of peptidoglycan biosynthesis.

    Science.gov (United States)

    Favini-Stabile, Sandy; Contreras-Martel, Carlos; Thielens, Nicole; Dessen, Andréa

    2013-12-01

    Peptidoglycan is a major determinant of cell shape in bacteria, and its biosynthesis involves the concerted action of cytoplasmic, membrane-associated and periplasmic enzymes. Within the cytoplasm, Mur enzymes catalyse the first steps leading to peptidoglycan precursor biosynthesis, and have been suggested as being part of a multicomponent complex that could also involve the transglycosylase MurG and the cytoskeletal protein MreB. In order to initialize the characterization of a potential Mur interaction network, we purified MurD, MurE, MurF, MurG and MreB from Thermotoga maritima and characterized their interactions using membrane blotting and surface plasmon resonance. MurD, MurE and MurF all recognize MurG and MreB, but not each other, while the two latter proteins interact. In addition, we solved the crystal structures of MurD, MurE and MurF, which indicate that their C-termini display high conformational flexibilities. The differences in Mur conformations could be important parameters for the stability of an intracytoplasmic murein biosynthesis complex. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  9. The MreB-like protein Mbl of Streptomyces coelicolor A3(2) depends on MreB for proper localization and contributes to spore wall synthesis.

    Science.gov (United States)

    Heichlinger, Andrea; Ammelburg, Moritz; Kleinschnitz, Eva-Maria; Latus, Annette; Maldener, Iris; Flärdh, Klas; Wohlleben, Wolfgang; Muth, Günther

    2011-04-01

    Most bacteria with a rod-shaped morphology contain an actin-like cytoskeleton consisting of MreB polymers, which form helical spirals underneath the cytoplasmic membrane to direct peptidoglycan synthesis for the elongation of the cell wall. In contrast, MreB of Streptomyces coelicolor is not required for vegetative growth but has a role in sporulation. Besides MreB, S. coelicolor encodes two further MreB-like proteins, Mbl and SCO6166, whose function is unknown. Whereas MreB and Mbl are highly similar, SCO6166 is shorter, lacking the subdomains IB and IIB of actin-like proteins. Here, we showed that MreB and Mbl are not functionally redundant but cooperate in spore wall synthesis. Expression analysis by semiquantitative reverse transcription-PCR revealed distinct expression patterns. mreB and mbl are induced predominantly during morphological differentiation. In contrast, sco6166 is strongly expressed during vegetative growth but switched off during sporulation. All genes could be deleted without affecting viability. Even a ΔmreB Δmbl double mutant was viable. Δsco6166 had a wild-type phenotype. ΔmreB, Δmbl, and ΔmreB Δmbl produced swollen, prematurely germinating spores that were sensitive to various kinds of stress, suggesting a defect in spore wall integrity. During aerial mycelium formation, an Mbl-mCherry fusion protein colocalized with an MreB-enhanced green fluorescent protein (MreB-eGFP) fusion protein at the sporulation septa. Whereas MreB-eGFP localized properly in the Δmbl mutant, Mbl-mCherry localization depended on the presence of a functional MreB protein. Our results revealed that MreB and Mbl cooperate in the synthesis of the thickened spore wall, while SCO6166 has a nonessential function during vegetative growth.

  10. Single molecules of the bacterial actin MreB undergo directed treadmilling motion in Caulobacter crescentus.

    Science.gov (United States)

    Kim, So Yeon; Gitai, Zemer; Kinkhabwala, Anika; Shapiro, Lucy; Moerner, W E

    2006-07-18

    The actin cytoskeleton represents a key regulator of multiple essential cellular functions in both eukaryotes and prokaryotes. In eukaryotes, these functions depend on the orchestrated dynamics of actin filament assembly and disassembly. However, the dynamics of the bacterial actin homolog MreB have yet to be examined in vivo. In this study, we observed the motion of single fluorescent MreB-yellow fluorescent protein fusions in living Caulobacter cells in a background of unlabeled MreB. With time-lapse imaging, polymerized MreB [filamentous MreB (fMreB)] and unpolymerized MreB [globular MreB (gMreB)] monomers could be distinguished: gMreB showed fast motion that was characteristic of Brownian diffusion, whereas the labeled molecules in fMreB displayed slow, directed motion. This directional movement of labeled MreB in the growing polymer provides an indication that, like actin, MreB monomers treadmill through MreB filaments by preferential polymerization at one filament end and depolymerization at the other filament end. From these data, we extract several characteristics of single MreB filaments, including that they are, on average, much shorter than the cell length and that the direction of their polarized assembly seems to be independent of the overall cellular polarity. Thus, MreB, like actin, exhibits treadmilling behavior in vivo, and the long MreB structures that have been visualized in multiple bacterial species seem to represent bundles of short filaments that lack a uniform global polarity.

  11. Influence of heterologous MreB proteins on cell morphology of Bacillus subtilis.

    Science.gov (United States)

    Schirner, Kathrin; Errington, Jeff

    2009-11-01

    The prokaryotic cytoskeletal protein MreB is thought to govern cell shape by positioning the cell wall synthetic apparatus at growth sites in the cell. In rod-shaped bacteria it forms helical filaments that run around the periphery of the rod during elongation. Gram-positive bacteria often contain more than one mreB gene. Bacillus subtilis has three mreB-like genes, mreB, mbl and mreBH, the first two of which have been shown to be essential under normal growth conditions. Expression of an mreB homologue from the closely related organism Bacillus licheniformis did not have any effect on cell growth or morphology. In contrast, expression of mreB from the phylogenetically more distant bacterium Clostridium perfringens produced shape defects and ultimately cell death, due to disruption of the endogenous MreB cytoskeleton. However, expression of either mreB(B. licheniformis) (mreB(Bl)) or mreB(C. perfringens) (mreB(Cp)) was sufficient to confer a rod shape to B. subtilis deleted for the three mreB isologues, supporting the idea that the three proteins have largely redundant functions in cell morphogenesis. Expression of mreBCD(Bl) could fully compensate for the loss of mreBCD in B. subtilis and led to the formation of rod-shaped cells. In contrast, expression of mreBCD(Cp) was not sufficient to confer a rod shape to B. subtilis Delta mreBCD, indicating that a complex of these three cell shape determinants is not enough for cell morphogenesis of B. subtilis.

  12. Assembly of the MreB-associated cytoskeletal ring of Escherichia coli.

    Science.gov (United States)

    Vats, Purva; Shih, Yu-Ling; Rothfield, Lawrence

    2009-04-01

    The Escherichia coli actin homologue MreB is part of a helical cytoskeletal structure that winds around the cell between the two poles. It has been shown that MreB redistributes during the cell cycle to form circumferential ring structures that flank the cytokinetic FtsZ ring and appear to be associated with division and segregation of the helical cytoskeleton. We show here that the MreB cytoskeletal ring also contains the MreC, MreD, Pbp2 and RodA proteins. Assembly of MreB, MreC, MreD and Pbp2 into the ring structure required the FtsZ ring but no other known components of the cell division machinery, whereas assembly of RodA into the cytoskeletal ring required one or more additional septasomal components. Strikingly, MreB, MreC, MreD and RodA were each able to independently assemble into the cytoskeletal ring and coiled cytoskeletal structures in the absence of any of the other ring components. This excludes the possibility that one or more of these proteins acts as a scaffold for incorporation of the other proteins into these structures. In contrast, incorporation of Pbp2 required the presence of MreC, which may provide a docking site for Pbp2 entry.

  13. Bacterial morphogenesis and the enigmatic MreB helix.

    Science.gov (United States)

    Errington, Jeff

    2015-04-01

    Work over the past decade has highlighted the pivotal role of the actin-like MreB family of proteins in the determination and maintenance of rod cell shape in bacteria. Early images of MreB localization revealed long helical filaments, which were suggestive of a direct role in governing cell wall architecture. However, several more recent, higher-resolution studies have questioned the existence or importance of the helical structures. In this Opinion article, I navigate a path through these conflicting reports, revive the helix model and summarize the key questions that remain to be answered.

  14. The small protein MbiA interacts with MreB and modulates cell shape in Caulobacter crescentus

    OpenAIRE

    Yakhnina, Anastasiya A.; Gitai, Zemer

    2012-01-01

    In Caulobacter crescentus, the actin homologue MreB is critical for cell shape maintenance. Despite the central importance of MreB for cell morphology and viability, very little is known about MreB-interacting factors. Here, we use an overexpression approach to identify a novel MreB interactor, MbiA. MbiA interacts with MreB in both biochemical and genetic assays, colocalizes with MreB throughout the cell cycle, and relies on MreB for its localization. MbiA over-expression mimics the loss of ...

  15. The actin homologue MreB organizes the bacterial cell membrane.

    Science.gov (United States)

    Strahl, Henrik; Bürmann, Frank; Hamoen, Leendert W

    2014-03-07

    The eukaryotic cortical actin cytoskeleton creates specific lipid domains, including lipid rafts, which determine the distribution of many membrane proteins. Here we show that the bacterial actin homologue MreB displays a comparable activity. MreB forms membrane-associated filaments that coordinate bacterial cell wall synthesis. We noticed that the MreB cytoskeleton influences fluorescent staining of the cytoplasmic membrane. Detailed analyses combining an array of mutants, using specific lipid staining techniques and spectroscopic methods, revealed that MreB filaments create specific membrane regions with increased fluidity (RIFs). Interference with these fluid lipid domains (RIFs) perturbs overall lipid homeostasis and affects membrane protein localization. The influence of MreB on membrane organization and fluidity may explain why the active movement of MreB stimulates membrane protein diffusion. These novel MreB activities add additional complexity to bacterial cell membrane organization and have implications for many membrane-associated processes.

  16. Assembly of MreB filaments on liposome membranes: a synthetic biology approach.

    Science.gov (United States)

    Maeda, Yusuke T; Nakadai, Tomoyoshi; Shin, Jonghyeon; Uryu, Kunihiro; Noireaux, Vincent; Libchaber, Albert

    2012-02-17

    The physical interaction between the cytoskeleton and the cell membrane is essential in defining the morphology of living organisms. In this study, we use a synthetic approach to polymerize bacterial MreB filaments inside phospholipid vesicles. When the proteins MreB and MreC are expressed inside the liposomes, the MreB cytoskeleton structure develops at the inner membrane. Furthermore, when purified MreB is used inside the liposomes, MreB filaments form a 4-10 μm rigid bundle structure and deform the lipid vesicles in physical contact with the vesicle inner membrane. These results indicate that the fibrillation of MreB filaments can take place either in close proximity of deformable lipid membrane or in the presence of associated protein. Our finding might be relevant for the self-assembly of cytoskeleton filaments toward the construction of artificial cell systems.

  17. 6 CFR 37.17 - Requirements for the surface of the driver's license or identification card.

    Science.gov (United States)

    2010-01-01

    ... Driver's license or identification card number. This cannot be the individual's SSN, and must be unique... University Street, Montreal, Quebec, Canada H3C 5H7, e-mail: [email protected] You may inspect a copy of the...

  18. Patterns and drivers of bacterial α- and β-diversity across vertical profiles from surface to subsurface sediments.

    Science.gov (United States)

    Luna, Gian Marco; Corinaldesi, Cinzia; Rastelli, Eugenio; Danovaro, Roberto

    2013-10-01

    We investigated the patterns and drivers of bacterial α- and β-diversity, along with viral and prokaryotic abundance and the carbon production rates, in marine surface and subsurface sediments (down to 1 m depth) in two habitats: vegetated sediments (seagrass meadow) and non-vegetated sediments. Prokaryotic abundance and production decreased with depth in the sediment, but cell-specific production rates and the virus-to-prokaryote ratio increased, highlighting unexpectedly high activity in the subsurface. The highest diversity was observed in vegetated sediments. Bacterial β-diversity between sediment horizons was high, and only a minor number of taxa was shared between surface and subsurface layers. Viruses significantly contributed to explain α- and β-diversity patterns. Despite potential limitations due to the only use of fingerprinting techniques, this study indicates that the coastal subsurface host highly active and diversified bacterial assemblages, that subsurface cells are more active than expected and that viruses promote β-diversity and stimulate bacterial metabolism in subsurface layers. The limited number of taxa shared between habitats, and between surface and subsurface sediment horizons, suggests that future investigations of the shallow subsurface will provide insights into the census of bacterial diversity, and the comprehension of the patterns and drivers of prokaryotic diversity in marine ecosystems. © 2013 John Wiley & Sons Ltd and Society for Applied Microbiology.

  19. MreB-Dependent Inhibition of Cell Elongation during the Escape from Competence in Bacillus subtilis.

    Science.gov (United States)

    Mirouze, Nicolas; Ferret, Cécile; Yao, Zhizhong; Chastanet, Arnaud; Carballido-López, Rut

    2015-06-01

    During bacterial exponential growth, the morphogenetic actin-like MreB proteins form membrane-associated assemblies that move processively following trajectories perpendicular to the long axis of the cell. Such MreB structures are thought to scaffold and restrict the movement of peptidoglycan synthesizing machineries, thereby coordinating sidewall elongation. In Bacillus subtilis, this function is performed by the redundant action of three MreB isoforms, namely MreB, Mbl and MreBH. mreB and mbl are highly transcribed from vegetative promoters. We have found that their expression is maximal at the end of exponential phase, and rapidly decreases to a low basal level upon entering stationary phase. However, in cells developing genetic competence, a stationary phase physiological adaptation, expression of mreB was specifically reactivated by the central competence regulator ComK. In competent cells, MreB was found in complex with several competence proteins by in vitro pull-down assays. In addition, it co-localized with the polar clusters formed by the late competence peripheral protein ComGA, in a ComGA-dependent manner. ComGA has been shown to be essential for the inhibition of cell elongation characteristic of cells escaping the competence state. We show here that the pathway controlling this elongation inhibition also involves MreB. Our findings suggest that ComGA sequesters MreB to prevent cell elongation and therefore the escape from competence.

  20. Localization and expression of MreB in Vibrio parahaemolyticus under different stresses.

    Science.gov (United States)

    Chiu, Shen-Wen; Chen, Shau-Yan; Wong, Hin-chung

    2008-11-01

    MreB, the homolog of eukaryotic actin, may play a vital role when prokaryotes cope with stress by altering their spatial organization, including their morphology, subcellular architecture, and localization of macromolecules. This study investigates the behavior of MreB in Vibrio parahaemolyticus under various stresses. The behavior of MreB was probed using a yellow fluorescent protein-MreB conjugate in merodiploid strain SC9. Under normal growth conditions, MreB formed helical filaments in exponential-phase cells. The shape of starved or stationary-phase cells changed from rods to small spheroids. The cells differentiated into the viable but nonculturable (VBNC) state with small spherical cells via a "swelling-waning" process. In all cases, drastic remodeling of the MreB cytoskeleton was observed. MreB helices typically were loosened and fragmented into short filaments, arcs, and spots in bacteria under these stresses. The disintegrated MreB exhibited a strong tendency to attach to the cytoplasmic membrane. The expression of mreB generally declined in bacteria in the stationary phase and under starvation but was upregulated during the initial periods of cold shock and VBNC state differentiation and decreased afterwards. Our findings demonstrated the behavior of MreB in the morphological changes of V. parahaemolyticus under intrinsic or extrinsic stresses and may have important implications for studying the cellular stress response and aging.

  1. MreB-Dependent Inhibition of Cell Elongation during the Escape from Competence in Bacillus subtilis.

    Directory of Open Access Journals (Sweden)

    Nicolas Mirouze

    2015-06-01

    Full Text Available During bacterial exponential growth, the morphogenetic actin-like MreB proteins form membrane-associated assemblies that move processively following trajectories perpendicular to the long axis of the cell. Such MreB structures are thought to scaffold and restrict the movement of peptidoglycan synthesizing machineries, thereby coordinating sidewall elongation. In Bacillus subtilis, this function is performed by the redundant action of three MreB isoforms, namely MreB, Mbl and MreBH. mreB and mbl are highly transcribed from vegetative promoters. We have found that their expression is maximal at the end of exponential phase, and rapidly decreases to a low basal level upon entering stationary phase. However, in cells developing genetic competence, a stationary phase physiological adaptation, expression of mreB was specifically reactivated by the central competence regulator ComK. In competent cells, MreB was found in complex with several competence proteins by in vitro pull-down assays. In addition, it co-localized with the polar clusters formed by the late competence peripheral protein ComGA, in a ComGA-dependent manner. ComGA has been shown to be essential for the inhibition of cell elongation characteristic of cells escaping the competence state. We show here that the pathway controlling this elongation inhibition also involves MreB. Our findings suggest that ComGA sequesters MreB to prevent cell elongation and therefore the escape from competence.

  2. GTPase activity, structure, and mechanical properties of filaments assembled from bacterial cytoskeleton protein MreB.

    Science.gov (United States)

    Esue, Osigwe; Wirtz, Denis; Tseng, Yiider

    2006-02-01

    MreB, a major component of the recently discovered bacterial cytoskeleton, displays a structure homologous to its eukaryotic counterpart actin. Here, we study the assembly and mechanical properties of Thermotoga maritima MreB in the presence of different nucleotides in vitro. We found that GTP, not ADP or GDP, can mediate MreB assembly into filamentous structures as effectively as ATP. Upon MreB assembly, both GTP and ATP release the gamma phosphate at similar rates. Therefore, MreB is an equally effective ATPase and GTPase. Electron microscopy and quantitative rheology suggest that the morphologies and micromechanical properties of filamentous ATP-MreB and GTP-MreB are similar. In contrast, mammalian actin assembly is favored in the presence of ATP over GTP. These results indicate that, despite high structural homology of their monomers, T. maritima MreB and actin filaments display different assembly, morphology, micromechanics, and nucleotide-binding specificity. Furthermore, the biophysical properties of T. maritima MreB filaments, including high rigidity and propensity to form bundles, suggest a mechanism by which MreB helical structure may be involved in imposing a cylindrical architecture on rod-shaped bacterial cells.

  3. Motion of single MreB bacterial actin proteins in Caulobacter show treadmilling in vivo

    Science.gov (United States)

    Moerner, W. E.; Kim, Soyeon; Gitai, Zemer; Kinkhabwala, Anika; McAdams, Harley; Shapiro, Lucy

    2006-03-01

    Ensemble imaging of a bacterial actin homologue, the MreB protein, suggests that the MreB proteins form a dynamic filamentous spiral along the long axis of the cell in Caulobacter crescentus. MreB contracts and expands along the cell axis and plays an important role in cell shape and polarity maintenance, as well as chromosome segregation and translocation of the origin of replication during cell division. In this study we investigated the real-time polymerization of MreB in Caulobacter crescentus using single-molecule fluorescence imaging. With time-lapse imaging, polymerized MreB could be distinguished from cytoplasmic MreB monomers, because single monomeric MreB showed fast motion characteristic of Brownian diffusion, while single polymerized MreB displayed slow, directed motion. This directional movement of labeled MreB in the growing polymer implies that treadmilling is the predominant mechanism in MreB filament formation. These single-molecule imaging experiments provide the first available information on the velocity of bacterial actin polymerization in a living cell.

  4. Effect of MRE11 loss on PARP-inhibitor sensitivity in endometrial cancer in vitro.

    Directory of Open Access Journals (Sweden)

    Romana Koppensteiner

    Full Text Available To evaluate the frequency of MRE11/RAD50/NBS1 (MRN-complex loss of protein expression in endometrial cancers (EC and to determine whether loss of MRE11 renders the cancer cells sensitive to Poly(ADP-ribose polymerase (PARP-inhibitory treatment.MRN expression was examined in 521 samples of endometrial carcinomas and in 10 cancer cell lines. A putative mutation hotspot in the form of an intronic poly(T allele in MRE11 was sequenced in selected cases (n = 26. Sensitivity to the PARP-inhibitor, BMN673 was tested in colony formation assays before and after MRE11 silencing using siRNA. Homologous recombination (HR DNA repair was evaluated by RAD51-foci formation assay upon irradiation and drug treatment.Loss of MRE11 protein was found in 30.7% of EC tumours and significantly associated with loss of RAD50, NBS1 and mismatch repair protein expression. One endometrial cell line showed a markedly reduced MRE11 expression due to a homozygous poly(T mutation of MRE11, thereby exhibiting an increased sensitivity to BMN673. MRE11 depletion sensitizes MRE11 expressing EC cell lines to the treatment with BMN673. The increased sensitivity to PARP-inhibition correlates with reduced RAD51 foci formation upon ionizing radiation in MRE11-depleted cells.Loss of the MRE11 protein predicts sensitivity to PARP-inhibitor sensitivity in vitro, defining it as an additional synthetic lethal gene with PARP. The high incidence of MRE11 loss in ECs can be potentially exploited for PARP-inhibitor therapy. Furthermore, MRE11 protein expression using immunohistochemistry could be investigated as a predictive biomarker for PARP-inhibitor treatment.

  5. How to Build a Bacterial Cell: MreB as the Foreman of E. coli Construction.

    Science.gov (United States)

    Shi, Handuo; Bratton, Benjamin P; Gitai, Zemer; Huang, Kerwyn Casey

    2018-03-08

    Cell shape matters across the kingdoms of life, and cells have the remarkable capacity to define and maintain specific shapes and sizes. But how are the shapes of micron-sized cells determined from the coordinated activities of nanometer-sized proteins? Here, we review general principles that have surfaced through the study of rod-shaped bacterial growth. Imaging approaches have revealed that polymers of the actin homolog MreB play a central role. MreB both senses and changes cell shape, thereby generating a self-organizing feedback system for shape maintenance. At the molecular level, structural and computational studies indicate that MreB filaments exhibit tunable mechanical properties that explain their preference for certain geometries and orientations along the cylindrical cell body. We illustrate the regulatory landscape of rod-shape formation and the connectivity between cell shape, cell growth, and other aspects of cell physiology. These discoveries provide a framework for future investigations into the architecture and construction of microbes. Copyright © 2018 Elsevier Inc. All rights reserved.

  6. Polymerization properties of the Thermotoga maritima actin MreB: roles of temperature, nucleotides, and ions.

    Science.gov (United States)

    Bean, Greg J; Amann, Kurt J

    2008-01-15

    MreB is a bacterial orthologue of actin that affects cell shape, polarity, and chromosome segregation. Although a significant body of work has explored its cellular functions, we know very little about the biochemical behavior of MreB. We have cloned, overexpressed in Escherichia coli, and purified untagged MreB1 from Thermotoga maritima. We have characterized the conditions that regulate its monomer-to-polymer assembly reaction, the critical concentrations of that reaction, the manner in which MreB uses nucleotides, its stability, and the structure of the assembled polymer. MreB requires a bound purine nucleotide for polymerization and rapidly hydrolyzes it following assembly. MreB assembly contains two distinct components, one that does not require divalent cations and one that does, which may comprise the nucleation and elongation phases of assembly, respectively. MreB assembly is strongly favored by increasing temperature or protein concentration but inhibited differentially by high concentrations of monovalent salts. The polymerization rate increases and the bulk critical concentration decreases with increasing temperature, but in contrast to previous reports, MreB is capable of polymerizing across a broad range of temperatures. MreB polymers are shorter and stiffer and scatter more light than eukaryotic actin filaments. Due to rapid ATP hydrolysis and phosphate release, we suggest that most assembled MreB in cells is in the ADP-bound state. Because of only moderate differences between the ATP and ADP critical concentrations, treadmilling may occur, but we do not predict dynamic instability in cells. Because of the relatively low cellular concentration of MreB and the observed structural properties of the polymer, a single MreB assembly may exist in cells.

  7. Steady-state MreB helices inside bacteria: dynamics without motors

    OpenAIRE

    Allard, Jun F.; Rutenberg, Andrew D.

    2007-01-01

    Within individual bacteria, we combine force-dependent polymerization dynamics of individual MreB protofilaments with an elastic model of protofilament bundles buckled into helical configurations. We use variational techniques and stochastic simulations to relate the pitch of the MreB helix, the total abundance of MreB, and the number of protofilaments. By comparing our simulations with mean-field calculations, we find that stochastic fluctuations are significant. We examine the quasi-static ...

  8. The actin homologue MreB organizes the bacterial cell membrane

    OpenAIRE

    Strahl, Henrik; Bürmann, Frank; Hamoen, Leendert W.

    2014-01-01

    The eukaryotic cortical actin cytoskeleton creates specific lipid domains, including lipid rafts, which determine the distribution of many membrane proteins. Here we show that the bacterial actin homologue MreB displays a comparable activity. MreB forms membrane-associated filaments that coordinate bacterial cell wall synthesis. We noticed that the MreB cytoskeleton influences fluorescent staining of the cytoplasmic membrane. Detailed analyses combining an array of mutants, using specific lip...

  9. Different roles of the Mre11 complex in the DNA damage response in Aspergillus nidulans.

    Science.gov (United States)

    Semighini, Camile P; von Zeska Kress Fagundes, Márcia Regina; Ferreira, Joseane Cristina; Pascon, Renata Castiglioni; de Souza Goldman, Maria Helena; Goldman, Gustavo Henrique

    2003-06-01

    The Mre11-Rad50-Nbs1 protein complex has emerged as a central player in the cellular DNA damage response. Mutations in scaANBS1, which encodes the apparent homologue of human Nbs1 in Aspergillus nidulans, inhibit growth in the presence of the anti-topoisomerase I drug camptothecin. We have used the scaANBS1 cDNA as a bait in a yeast two-hybrid screening and report the identification of the A. nidulans Mre11 homologue (mreA). The inactivated mreA strain was more sensitive to several DNA damaging and oxidative stress agents. Septation in A. nidulans is dependent not only on the uvsBATR gene, but also on the mre11 complex. scaANBS1 and mreA genes are both involved in the DNA replication checkpoint whereas mreA is specifically involved in the intra-S-phase checkpoint. ScaANBS1 also participates in G2-M checkpoint control upon DNA damage caused by MMS. In addition, the scaANBS1 gene is also important for ascospore viability, whereas mreA is required for successful meiosis in A. nidulans. Consistent with this view, the Mre11 complex and the uvsCRAD51 gene are highly expressed at the mRNA level during the sexual development.

  10. Characterization of MreB polymers in E. coli and their correlations to cell shape

    Science.gov (United States)

    Nguyen, Jeffrey; Ouzonov, Nikolay; Gitai, Zemer; Shaevitz, Joshua

    2015-03-01

    Shape influences all facets of how bacteria interact with their environment. The size of E. coli is determined by the peptidoglycan cell wall and internal turgor pressure. The cell wall is patterned by MreB, an actin homolog that forms short polymers on the cytoplasmic membrane. MreB coordinates the breaking of old material and the insertion of new material for growth, but it is currently unknown what mechanism sets the absolute diameter of the cell. Using new techniques in fluorescence microscopy and image processing, we are able to quantify cell shape in 3- dimensions and access previously unattainable data on the conformation of MreB polymers. To study how MreB affects the diameter of bacteria, we analyzed the shapes and polymers of cells that have had MreB perturbed by one of two methods. We first treated cells with the MreB polymerization-inhibiting drug A22. Secondly, we created point mutants in MreB that change MreB polymer conformation and the cell shape. By analyzing the correlations between different shape and polymer metrics, we find that under both treatments, the average helical pitch angle of the polymers correlates strongly with the cell diameter. This observation links the micron scale shape of the cell to the nanometer scale MreB cytoskeleton.

  11. The assembly of MreB, a prokaryotic homolog of actin.

    Science.gov (United States)

    Esue, Osigwe; Cordero, Maria; Wirtz, Denis; Tseng, Yiider

    2005-01-28

    MreB, a major component of the bacterial cytoskeleton, exhibits high structural homology to its eukaryotic counterpart actin. Live cell microscopy studies suggest that MreB molecules organize into large filamentous spirals that support the cell membrane and play a key shape-determining function. However, the basic properties of MreB filament assembly remain unknown. Here, we studied the assembly of Thermotoga maritima MreB triggered by ATP in vitro and compared it to the well-studied assembly of actin. These studies show that MreB filament ultrastructure and polymerization depend crucially on temperature as well as the ions present on solution. At the optimal growth temperature of T. maritima, MreB assembly proceeded much faster than that of actin, without nucleation (or nucleation is highly favorable and fast) and with little or no contribution from filament end-to-end annealing. MreB exhibited rates of ATP hydrolysis and phosphate release similar to that of F-actin, however, with a critical concentration of approximately 3 nm, which is approximately 100-fold lower than that of actin. Furthermore, MreB assembled into filamentous bundles that have the ability to spontaneously form ring-like structures without auxiliary proteins. These findings suggest that despite high structural homology, MreB and actin display significantly different assembly properties.

  12. The actin homologue MreB organizes the bacterial cell membrane

    NARCIS (Netherlands)

    Strahl, H.; Burmann, F.; Hamoen, L.W.

    2014-01-01

    The eukaryotic cortical actin cytoskeleton creates specific lipid domains, including lipid rafts, which determine the distribution of many membrane proteins. Here we show that the bacterial actin homologue MreB displays a comparable activity. MreB forms membrane-associated filaments that coordinate

  13. Exploring the A22-Bacterial Actin MreB Interaction through Molecular Dynamics Simulations.

    Science.gov (United States)

    Awuni, Yaw; Jiang, Shimin; Robinson, Robert C; Mu, Yuguang

    2016-09-22

    MreB is an actin-like cytoskeleton protein that plays a vital role in the maintenance of the rod-shaped morphology of many bacteria. S-(3,4-Dichlorobenzyl) isothiourea (A22) is an antibiotic-like small molecule that perturbs the rod cell shape and has been suggested to inhibit MreB by targeting ATP hydrolysis. However, without the elucidation of the structure of the ATP-bound state of MreB in the presence of A22, the mechanism of A22 inhibition is still not clear. Here we apply conventional molecular dynamics simulations to explore the dynamics of the active site of MreB in complex with A22 and different nucleotides. We observe that hydrogen bonding between A22 and the catalytic Glu140 residue is not favored in the ATP-A22-bound state of MreB. Water dynamics analysis in the MreB active site reveals that in the presence of A22 water molecules are able to occupy positions suitable for ATP hydrolysis. Overall, our results are consistent with a mechanism in which A22 affects MreB polymerization/depolymerization dynamics in part through slowing phosphate release rather than by inhibiting ATP hydrolysis. These data can be incorporated in the design/development of the next generation of MreB inhibitors.

  14. MreB filaments align along greatest principal membrane curvature to orient cell wall synthesis

    Science.gov (United States)

    Szwedziak, Piotr; Wong, Felix; Schaefer, Kaitlin; Izoré, Thierry; Renner, Lars D; Holmes, Matthew J; Sun, Yingjie; Bisson-Filho, Alexandre W; Walker, Suzanne; Amir, Ariel; Löwe, Jan

    2018-01-01

    MreB is essential for rod shape in many bacteria. Membrane-associated MreB filaments move around the rod circumference, helping to insert cell wall in the radial direction to reinforce rod shape. To understand how oriented MreB motion arises, we altered the shape of Bacillus subtilis. MreB motion is isotropic in round cells, and orientation is restored when rod shape is externally imposed. Stationary filaments orient within protoplasts, and purified MreB tubulates liposomes in vitro, orienting within tubes. Together, this demonstrates MreB orients along the greatest principal membrane curvature, a conclusion supported with biophysical modeling. We observed that spherical cells regenerate into rods in a local, self-reinforcing manner: rapidly propagating rods emerge from small bulges, exhibiting oriented MreB motion. We propose that the coupling of MreB filament alignment to shape-reinforcing peptidoglycan synthesis creates a locally-acting, self-organizing mechanism allowing the rapid establishment and stable maintenance of emergent rod shape. PMID:29469806

  15. The cellular Mre11 protein interferes with adenovirus E4 mutant DNA replication

    International Nuclear Information System (INIS)

    Mathew, Shomita S.; Bridge, Eileen

    2007-01-01

    Adenovirus type 5 (Ad5) relocalizes and degrades the host DNA repair protein Mre11, and efficiently initiates viral DNA replication. Mre11 associates with Ad E4 mutant DNA replication centers and is important for concatenating viral genomes. We have investigated the role of Mre11 in the E4 mutant DNA replication defect. RNAi-mediated knockdown of Mre11 dramatically rescues E4 mutant DNA replication in cells that do or do not concatenate viral genomes, suggesting that Mre11 inhibits DNA replication independent of genome concatenation. The mediator of DNA damage checkpoint 1 (Mdc1) protein is involved in recruiting and sustaining Mre11 at sites of DNA damage following ionizing radiation. We observe foci formation by Mdc1 in response to viral infection, indicating that this damage response protein is activated. However, knockdown of Mdc1 does not prevent Mre11 from localizing at viral DNA replication foci or rescue E4 mutant DNA replication. Our results are consistent with a model in which Mre11 interferes with DNA replication when it is localized at viral DNA replication foci

  16. The small protein MbiA interacts with MreB and modulates cell shape in Caulobacter crescentus.

    Science.gov (United States)

    Yakhnina, Anastasiya A; Gitai, Zemer

    2012-09-01

    In Caulobacter crescentus, the actin homologue MreB is critical for cell shape maintenance. Despite the central importance of MreB for cell morphology and viability, very little is known about MreB-interacting factors. Here, we use an overexpression approach to identify a novel MreB interactor, MbiA. MbiA interacts with MreB in both biochemical and genetic assays, colocalizes with MreB throughout the cell cycle, and relies on MreB for its localization. MbiA overexpression mimics the loss of MreB function, severely perturbing cell morphology, inhibiting growth and inducing cell lysis. Additionally, mbiA deletion shows a synthetic growth phenotype with a hypomorphic allele of the MreB interactor RodZ, suggesting that these two MreB-interacting proteins either have partially redundant functions or participate in the same functional complex. Our work thus establishes MbiA as a novel cell shape regulator that appears to function through regulating MreB, and opens avenues for discovery of more MreB-regulating factors by showing that overexpression screens are a valuable tool for uncovering potentially redundant cell shape effectors. © 2012 Blackwell Publishing Ltd.

  17. Steady-state configurations and dynamics of the MreB helix within bacteria

    Science.gov (United States)

    Rutenberg, Andrew; Allard, Jun

    2007-03-01

    We present a quantitative model of the actin-like MreB cytoskeleton that is present in many prokaryotes. Individual MreB polymers are bundled into a supra-molecular array to make up helical cables. The cell wall imposes constraint forces through a global elasticity model. With variational techniques and stochastic simulations we obtain relationships between observable quantities such as the pitch of the helix, the total abundance of MreB molecules, and the thickness of the MreB cables. We address changes expected with slow cell growth, as well as turnover dynamics that are relevant to FRAP studies. We also address polarized macromolecular trafficking along the MreB cables without motor proteins.

  18. Processive movement of MreB-associated cell wall biosynthetic complexes in bacteria.

    Science.gov (United States)

    Domínguez-Escobar, Julia; Chastanet, Arnaud; Crevenna, Alvaro H; Fromion, Vincent; Wedlich-Söldner, Roland; Carballido-López, Rut

    2011-07-08

    The peptidoglycan cell wall and the actin-like MreB cytoskeleton are major determinants of cell shape in rod-shaped bacteria. The prevailing model postulates that helical, membrane-associated MreB filaments organize elongation-specific peptidoglycan-synthesizing complexes along sidewalls. We used total internal reflection fluorescence microscopy to visualize the dynamic relation between MreB isoforms and cell wall synthesis in live Bacillus subtilis cells. During exponential growth, MreB proteins did not form helical structures. Instead, together with other morphogenetic factors, they assembled into discrete patches that moved processively along peripheral tracks perpendicular to the cell axis. Patch motility was largely powered by cell wall synthesis, and MreB polymers restricted diffusion of patch components in the membrane and oriented patch motion.

  19. Duplication and segregation of the actin (MreB) cytoskeleton during the prokaryotic cell cycle.

    Science.gov (United States)

    Vats, Purva; Rothfield, Lawrence

    2007-11-06

    The bacterial actin homolog MreB exists as a single-copy helical cytoskeletal structure that extends between the two poles of rod-shaped bacteria. In this study, we show that equipartition of the MreB cytoskeleton into daughter cells is accomplished by division and segregation of the helical MreB array into two equivalent structures located in opposite halves of the predivisional cell. This process ensures that each daughter cell inherits one copy of the MreB cytoskeleton. The process is triggered by the membrane association of the FtsZ cell division protein. The cytoskeletal division and segregation events occur before and independently of cytokinesis and involve specialized MreB structures that appear to be intermediates in this process.

  20. Steady-state helices of the actin homolog MreB inside bacteria: Dynamics without motors

    Science.gov (United States)

    Allard, Jun F.; Rutenberg, Andrew D.

    2007-09-01

    Within individual bacteria, we combine force-dependent polymerization dynamics of individual MreB protofilaments with an elastic model of protofilament bundles buckled into helical configurations. We use variational techniques and stochastic simulations to relate the pitch of the MreB helix, the total abundance of MreB, and the number of protofilaments. By comparing our simulations with mean-field calculations, we find that stochastic fluctuations are significant. We examine the quasistatic evolution of the helical pitch with cell growth, as well as time scales of helix turnover and de novo establishment. We find that while the body of a polarized MreB helix treadmills toward its slow-growing end, the fast-growing tips of laterally associated protofilaments move toward the opposite fast-growing end of the MreB helix. This offers a possible mechanism for targeted polar localization without cytoplasmic motor proteins.

  1. The MreB-Like Protein Mbl of Streptomyces coelicolor A3(2) Depends on MreB for Proper Localization and Contributes to Spore Wall Synthesis▿ †

    Science.gov (United States)

    Heichlinger, Andrea; Ammelburg, Moritz; Kleinschnitz, Eva-Maria; Latus, Annette; Maldener, Iris; Flärdh, Klas; Wohlleben, Wolfgang; Muth, Günther

    2011-01-01

    Most bacteria with a rod-shaped morphology contain an actin-like cytoskeleton consisting of MreB polymers, which form helical spirals underneath the cytoplasmic membrane to direct peptidoglycan synthesis for the elongation of the cell wall. In contrast, MreB of Streptomyces coelicolor is not required for vegetative growth but has a role in sporulation. Besides MreB, S. coelicolor encodes two further MreB-like proteins, Mbl and SCO6166, whose function is unknown. Whereas MreB and Mbl are highly similar, SCO6166 is shorter, lacking the subdomains IB and IIB of actin-like proteins. Here, we showed that MreB and Mbl are not functionally redundant but cooperate in spore wall synthesis. Expression analysis by semiquantitative reverse transcription-PCR revealed distinct expression patterns. mreB and mbl are induced predominantly during morphological differentiation. In contrast, sco6166 is strongly expressed during vegetative growth but switched off during sporulation. All genes could be deleted without affecting viability. Even a ΔmreB Δmbl double mutant was viable. Δsco6166 had a wild-type phenotype. ΔmreB, Δmbl, and ΔmreB Δmbl produced swollen, prematurely germinating spores that were sensitive to various kinds of stress, suggesting a defect in spore wall integrity. During aerial mycelium formation, an Mbl-mCherry fusion protein colocalized with an MreB-enhanced green fluorescent protein (MreB-eGFP) fusion protein at the sporulation septa. Whereas MreB-eGFP localized properly in the Δmbl mutant, Mbl-mCherry localization depended on the presence of a functional MreB protein. Our results revealed that MreB and Mbl cooperate in the synthesis of the thickened spore wall, while SCO6166 has a nonessential function during vegetative growth. PMID:21257777

  2. MreB Drives De Novo Rod Morphogenesis in Caulobacter crescentus via Remodeling of the Cell Wall

    OpenAIRE

    Takacs, Constantin N.; Poggio, Sebastian; Charbon, Godefroid; Pucheault, Mathieu; Vollmer, Waldemar; Jacobs-Wagner, Christine

    2010-01-01

    MreB, the bacterial actin-like cytoskeleton, is required for the rod morphology of many bacterial species. Disruption of MreB function results in loss of rod morphology and cell rounding. Here, we show that the widely used MreB inhibitor A22 causes MreB-independent growth inhibition that varies with the drug concentration, culture medium conditions, and bacterial species tested. MP265, an A22 structural analog, is less toxic than A22 for growth yet equally efficient for disrupting the MreB cy...

  3. Motion of variable-length MreB filaments at the bacterial cell membrane influences cell morphology

    OpenAIRE

    Reimold, Christian; Defeu Soufo, Herve Joel; Dempwolff, Felix; Graumann, Peter L.

    2013-01-01

    The maintenance of rod-cell shape in many bacteria depends on actin-like MreB proteins and several membrane proteins that interact with MreB. Using superresolution microscopy, we show that at 50-nm resolution, Bacillus subtilis MreB forms filamentous structures of length up to 3.4 ?m underneath the cell membrane, which run at angles diverging up to 40? relative to the cell circumference. MreB from Escherichia coli forms at least 1.4-?m-long filaments. MreB filaments move along various tracks ...

  4. 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.

  5. 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.

    Science.gov (United States)

    Defeu Soufo, Hervé Joël; Graumann, Peter L

    2005-03-03

    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. 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. 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.

  6. Dynamic localization of MreB in Vibrio parahaemolyticus and in the ectopic host bacterium Escherichia coli.

    Science.gov (United States)

    Chiu, Shen-Wen; Chen, Shau-Yan; Wong, Hin-chung

    2008-11-01

    MreB, a homolog of eukaryotic actin, participates in morphogenesis, cell division, cell polarity, and chromosome segregation in prokaryotes. In this study, a yellow fluorescent protein conjugate (YFP-MreB(Vp)) was generated to investigate the behavior of MreB in merodiploid strain SC9 of the enteropathogen Vibrio parahaemolyticus. Under normal growth conditions, YFP-MreB(Vp) formed helical filaments with a pitch of 0.64 +/- 0.09 microm in about 85% of exponential-phase cells, and different clusters, relaxed coils, and ring configurations were observed in a small proportion of the cells. Overexpression of YFP-MreB(Vp) substantially altered the structure of the MreB cytoskeleton and resulted in swollen and pleomorphic cells. Disturbing the activities of penicillin-binding proteins or adding magnesium suppressed the morphological distortions. These results indicate that mislocalization of cell wall-synthesizing machinery was responsible for morphological abnormality. By expressing YFP-MreB(Vp) in the ectopic host bacterium Escherichia coli, shrinkage, fragmentation, and annealing of MreB(Vp) filaments were directly observed. This work revealed the dynamic pattern of the localization of YFP-MreB(Vp) in V. parahaemolyticus and its relationship to cell morphogenesis, and the YFP-MreB(Vp)-E. coli system may be used to investigate the dynamic spatial structures of the MreB cytoskeleton in vivo.

  7. CbtA toxin of Escherichia coli inhibits cell division and cell elongation via direct and independent interactions with FtsZ and MreB.

    Science.gov (United States)

    Heller, Danielle M; Tavag, Mrinalini; Hochschild, Ann

    2017-09-01

    The toxin components of toxin-antitoxin modules, found in bacterial plasmids, phages, and chromosomes, typically target a single macromolecule to interfere with an essential cellular process. An apparent exception is the chromosomally encoded toxin component of the E. coli CbtA/CbeA toxin-antitoxin module, which can inhibit both cell division and cell elongation. A small protein of only 124 amino acids, CbtA, was previously proposed to interact with both FtsZ, a tubulin homolog that is essential for cell division, and MreB, an actin homolog that is essential for cell elongation. However, whether or not the toxic effects of CbtA are due to direct interactions with these predicted targets is not known. Here, we genetically separate the effects of CbtA on cell elongation and cell division, showing that CbtA interacts directly and independently with FtsZ and MreB. Using complementary genetic approaches, we identify the functionally relevant target surfaces on FtsZ and MreB, revealing that in both cases, CbtA binds to surfaces involved in essential cytoskeletal filament architecture. We show further that each interaction contributes independently to CbtA-mediated toxicity and that disruption of both interactions is required to alleviate the observed toxicity. Although several other protein modulators are known to target FtsZ, the CbtA-interacting surface we identify represents a novel inhibitory target. Our findings establish CbtA as a dual function toxin that inhibits both cell division and cell elongation via direct and independent interactions with FtsZ and MreB.

  8. BolA inhibits cell elongation and regulates MreB expression levels.

    Science.gov (United States)

    Freire, Patrick; Moreira, Ricardo Neves; Arraiano, Cecília Maria

    2009-02-06

    The morphogene bolA is a general stress response gene in Escherichia coli that induces a round morphology when overexpressed. Results presented in this report show that increased BolA levels can inhibit cell elongation mechanisms. MreB polymerization is crucial for the bacterial cell cytoskeleton, and this protein is essential for the maintenance of a cellular rod shape. In this report, we demonstrate that bolA overexpression affects the architecture of MreB filaments. An increase in BolA leads to a significant reduction in MreB protein levels and mreB transcripts. BolA affects the mreBCD operon in vivo at the level of transcription. Furthermore, our results show that BolA is a new transcriptional repressor of MreB. The alterations in cell morphology induced by bolA seem to be mediated by a complex pathway that integrates PBP5, PBP6, MreB, and probably other regulators of cell morphology/elongation.

  9. Post-transcriptional regulation of MRE11 expression in muscle-invasive bladder tumours.

    Science.gov (United States)

    Martin, Rebecca M; Kerr, Martin; Teo, Mark T W; Jevons, Sarah J; Koritzinsky, Marianne; Wouters, Bradly G; Bhattarai, Selina; Kiltie, Anne E

    2014-02-28

    Predictive assays are needed to help optimise treatment in muscle-invasive bladder cancer, where patients can be treated by either cystectomy or radical radiotherapy. Our finding that low tumour MRE11 expression is predictive of poor response to radiotherapy but not cystectomy was recently independently validated. Here we investigated further the mechanism underlying low MRE11 expression seen in poorly-responding patients. MRE11 RNA and protein levels were measured in 88 bladder tumour patient samples, by real-time PCR and immunohistochemistry respectively, and a panel of eight bladder cancer cell lines was screened for MRE11, RAD50 and NBS1 mRNA and protein expression. There was no correlation between bladder tumour MRE11 protein and RNA scores (Spearman's rho 0.064, p=0.65), suggesting MRE11 is controlled post-transcriptionally, a pattern confirmed in eight bladder cancer cell lines. In contrast, NBS1 and RAD50 mRNA and protein levels were correlated (p=0.01 and p=0.03, respectively), suggesting primary regulation at the level of transcription. MRE11 protein levels were correlated with NBS1 and RAD50 mRNA and protein levels, implicating MRN complex formation as an important determinant of MRE11 expression, driven by RAD50 and NBS1 expression. Our findings of the post-transcriptional nature of the control of MRE11 imply that any predictive assays used in patients need to be performed at the protein level rather than the mRNA level.

  10. Surface covering of downed logs: drivers of a neglected process in dead wood ecology.

    Science.gov (United States)

    Dynesius, Mats; Gibb, Heloise; Hjältén, Joakim

    2010-10-07

    Many species use coarse woody debris (CWD) and are disadvantaged by the forestry-induced loss of this resource. A neglected process affecting CWD is the covering of the surfaces of downed logs caused by sinking into the ground (increasing soil contact, mostly covering the underside of the log), and dense overgrowth by ground vegetation. Such cover is likely to profoundly influence the quality and accessibility of CWD for wood-inhabiting organisms, but the factors affecting covering are largely unknown. In a five-year experiment we determined predictors of covering rate of fresh logs in boreal forests and clear-cuts. Logs with branches were little covered because they had low longitudinal ground contact. For branchless logs, longitudinal ground contact was most strongly related to estimated peat depth (positive relation). The strongest predictor for total cover of branchless logs was longitudinal ground contact. To evaluate the effect on cover of factors other than longitudinal ground contact, we separately analyzed data from only those log sections that were in contact with the ground. Four factors were prominent predictors of percentage cover of such log sections: estimated peat depth, canopy shade (both increasing cover), potential solar radiation calculated from slope and slope aspect, and diameter of the log (both reducing cover). Peat increased cover directly through its low resistance, which allowed logs to sink and soil contact to increase. High moisture and low temperatures in pole-ward facing slopes and under a canopy favor peat formation through lowered decomposition and enhanced growth of peat-forming mosses, which also proved to rapidly overgrow logs. We found that in some boreal forests, peat and fast-growing mosses can rapidly cover logs lying on the ground. When actively introducing CWD for conservation purposes, we recommend that such rapid covering is avoided, thereby most likely improving the CWD's longevity as habitat for many species.

  11. Integracija digitalne radio-difuzne mreže mobilne televizije i ćelijske mreže treće generacije

    Directory of Open Access Journals (Sweden)

    Milan Manojle Šunjevarić

    2013-02-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 U radu su prikazani rezultati istraživanja mogućnosti za integraciju radio-difuznih mreža za mobilnu televiziju i ćelijskih mreža treće generacije (3G. Analizirani su trendovi u pogledu razvoja usluge mobilne televizije, i dosadašnja istraživanja koja imaju za cilj traženje optimalnih načina za integraciju različitih tipova mreža. U radu su analizirane postojeće tehnologije za mobilnu televiziju, s posebnim osvrtom na DVB-H (Digital Video Broadcasting - Handheld tehnologiju. Analizirani su preduslovi, razlozi i mogućnosti za integraciju DVB-H i 3G mreže UMTS (Universal Mobile Telecommunications System, a zaključci ovih analiza su potkrepljeni rezultatima praktičnog rada. Na osnovu svih ovih istraživanja donesen je zaključak o opravdanosti realizacije hibridne DVB-H/UMTS mreže.

  12. DRIVER INATTENTION

    Directory of Open Access Journals (Sweden)

    Richard TAY

    2004-01-01

    Full Text Available Driver inattention, especially driver distraction, is an extremely influential but generally neglected contributing factor of road crashes. This paper explores some of the common behaviours associated with several common forms of driver inattention, with respect to their perceived crash risks, rates of self-reported behaviours and whether drivers regulate such behaviours depending on the road and traffic environment, and provides some policy recommendations to address issues raised.

  13. Bacillus subtilis MreB paralogues have different filament architectures and lead to shape remodelling of a heterologous cell system.

    Science.gov (United States)

    Soufo, Hervé Joël Defeu; Graumann, Peter L

    2010-12-01

    Like many bacteria, Bacillus subtilis cells contain three actin-like MreB proteins. We show that the three paralogues, MreB, Mbl and MreBH, have different filament architectures in a heterologous cell system, and form straight filaments, helices or ring structures, different from the regular helical arrangement in B. subtilis cells. However, when coexpressed, they colocalize into a single filamentous helical structure, showing that the paralogues influence each other's filament architecture. Ring-like MreBH structures can be converted into MreB-like helical filaments by a single point mutation affecting subunit contacts, showing that MreB paralogues feature flexible filament arrangements. Time-lapse and FRAP experiments show that filaments can extend as well as shrink at both ends, and also show internal rearrangement, suggesting that filaments consist of overlapping bundles of shorter filaments that continuously turn over. Upon induction in Escherichia coli cells, B. subtilis MreB (BsMreB) filaments push the cells into strikingly altered cell morphology, showing that MreB filaments can change cell shape. E. coli cells with a weakened cell wall were ruptured upon induction of BsMreB filaments, suggesting that the bacterial actin orthologue may exert force against the cell membrane and envelope, and thus possibly plays an additional mechanical role in bacteria. © 2010 Blackwell Publishing Ltd.

  14. MreB drives de novo rod morphogenesis in Caulobacter crescentus via remodeling of the cell wall.

    Science.gov (United States)

    Takacs, Constantin N; Poggio, Sebastian; Charbon, Godefroid; Pucheault, Mathieu; Vollmer, Waldemar; Jacobs-Wagner, Christine

    2010-03-01

    MreB, the bacterial actin-like cytoskeleton, is required for the rod morphology of many bacterial species. Disruption of MreB function results in loss of rod morphology and cell rounding. Here, we show that the widely used MreB inhibitor A22 causes MreB-independent growth inhibition that varies with the drug concentration, culture medium conditions, and bacterial species tested. MP265, an A22 structural analog, is less toxic than A22 for growth yet equally efficient for disrupting the MreB cytoskeleton. The action of A22 and MP265 is enhanced by basic pH of the culture medium. Using this knowledge and the rapid reversibility of drug action, we examined the restoration of rod shape in lemon-shaped Caulobacter crescentus cells pretreated with MP265 or A22 under nontoxic conditions. We found that reversible restoration of MreB function after drug removal causes extensive morphological changes including a remarkable cell thinning accompanied with elongation, cell branching, and shedding of outer membrane vesicles. We also thoroughly characterized the composition of C. crescentus peptidoglycan by high-performance liquid chromatography and mass spectrometry and showed that MreB disruption and recovery of rod shape following restoration of MreB function are accompanied by considerable changes in composition. Our results provide insight into MreB function in peptidoglycan remodeling and rod shape morphogenesis and suggest that MreB promotes the transglycosylase activity of penicillin-binding proteins.

  15. Large-scale purification and in vitro characterization of the assembly of MreB from Leptospira interrogans.

    Science.gov (United States)

    Barkó, Szilvia; Szatmári, Dávid; Bódis, Emőke; Türmer, Katalin; Ujfalusi, Zoltán; Popp, David; Robinson, Robert C; Nyitrai, Miklós

    2016-09-01

    Weil's syndrome is caused by Leptospira interrogans infections, a Gram negative bacterium with a distinct thin corkscrew cell shape. The molecular basis for this unusual morphology is unknown. In many bacteria, cell wall synthesis is orchestrated by the actin homolog, MreB. Here we have identified the MreB within the L. interrogans genome and expressed the His-tagged protein product of the synthesized gene (Li-MreB) in Escherichia coli. Li-MreB did not purify under standard nucleotide-free conditions used for MreBs from other species, requiring the continual presence of ATP to remain soluble. Covalent modification of Li-MreB free thiols with Alexa488 produced a fluorescent version of Li-MreB. We developed native and denaturing/refolding purification schemes for Li-MreB. The purified product was shown to assemble and disassemble in MgCl2 and KCl dependent manners, as monitored by light scattering and sedimentation studies. The fluorescence spectrum of labeled Li-MreB-Alexa488 showed cation-induced changes in line with an activation process followed by a polymerization phase. The resulting filaments appeared as bundles and sheets under the fluorescence microscope. Finally, since the Li-MreB polymerization was cation dependent, we developed a simple method to measure monovalent cation concentrations within a test case prokaryote, E. coli. We have identified and initially characterized the cation-dependent polymerization properties of a novel MreB from a non-rod shaped bacterium and developed a method to measure cation concentrations within prokaryotes. This initial characterization of Li-MreB will enable future structural determination of the MreB filament from this corkscrew-shaped bacterium. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. A Qualitative Study of Soldier Perceptions of the Relative Importance of MRE Portion Size and Variety

    National Research Council Canada - National Science Library

    Bell, R

    1999-01-01

    .... Bliss, Biggs Army Airfield, and Fort Leonard Wood during 1997 to understand how soldiers perceive Meal, Ready-to-Eat portion size and MRE variety and to begin to determine what types of trade offs...

  17. The actin-like MreB cytoskeleton organizes viral DNA replication in bacteria.

    Science.gov (United States)

    Muñoz-Espín, Daniel; Daniel, Richard; Kawai, Yoshikazu; Carballido-López, Rut; Castilla-Llorente, Virginia; Errington, Jeff; Meijer, Wilfried J J; Salas, Margarita

    2009-08-11

    Little is known about the organization or proteins involved in membrane-associated replication of prokaryotic genomes. Here we show that the actin-like MreB cytoskeleton of the distantly related bacteria Escherichia coli and Bacillus subtilis is required for efficient viral DNA replication. Detailed analyses of B. subtilis phage ϕ29 showed that the MreB cytoskeleton plays a crucial role in organizing phage DNA replication at the membrane. Thus, phage double-stranded DNA and components of the ϕ29 replication machinery localize in peripheral helix-like structures in a cytoskeleton-dependent way. Importantly, we show that MreB interacts directly with the ϕ29 membrane-protein p16.7, responsible for attaching viral DNA at the cell membrane. Altogether, the results reveal another function for the MreB cytoskeleton and describe a mechanism by which viral DNA replication is organized at the bacterial membrane.

  18. Functional analysis of the cytoskeleton protein MreB from Chlamydophila pneumoniae.

    Science.gov (United States)

    Gaballah, Ahmed; Kloeckner, Anna; Otten, Christian; Sahl, Hans-Georg; Henrichfreise, Beate

    2011-01-01

    In rod-shaped bacteria, the bacterial actin ortholog MreB is considered to organize the incorporation of cell wall precursors into the side-wall, whereas the tubulin homologue FtsZ is known to tether incorporation of cell wall building blocks at the developing septum. For intracellular bacteria, there is no need to compensate osmotic pressure by means of a cell wall, and peptidoglycan has not been reliably detected in Chlamydiaceae. Surprisingly, a nearly complete pathway for the biosynthesis of the cell wall building block lipid II has been found in the genomes of Chlamydiaceae. In a previous study, we discussed the hypothesis that conservation of lipid II biosynthesis in cell wall-lacking bacteria may reflect the intimate molecular linkage of cell wall biosynthesis and cell division and thus an essential role of the precursor in cell division. Here, we investigate why spherical-shaped chlamydiae harbor MreB which is almost exclusively found in elongated bacteria (i.e. rods, vibrios, spirilla) whereas they lack the otherwise essential division protein FtsZ. We demonstrate that chlamydial MreB polymerizes in vitro and that polymerization is not inhibited by the blocking agent A22. As observed for MreB from Bacillus subtilis, chlamydial MreB does not require ATP for polymerization but is capable of ATP hydrolysis in phosphate release assays. Co-pelleting and bacterial two-hybrid experiments indicate that MreB from Chlamydophila (Chlamydia) pneumoniae interacts with MurF, MraY and MurG, three key components in lipid II biosynthesis. In addition, MreB polymerization is improved in the presence of MurF. Our findings suggest that MreB is involved in tethering biosynthesis of lipid II and as such may be necessary for maintaining a functional divisome machinery in Chlamydiaceae.

  19. The bacterial actin MreB rotates, and rotation depends on cell-wall assembly.

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    van Teeffelen, Sven; Wang, Siyuan; Furchtgott, Leon; Huang, Kerwyn Casey; Wingreen, Ned S; Shaevitz, Joshua W; Gitai, Zemer

    2011-09-20

    Bacterial cells possess multiple cytoskeletal proteins involved in a wide range of cellular processes. These cytoskeletal proteins are dynamic, but the driving forces and cellular functions of these dynamics remain poorly understood. Eukaryotic cytoskeletal dynamics are often driven by motor proteins, but in bacteria no motors that drive cytoskeletal motion have been identified to date. Here, we quantitatively study the dynamics of the Escherichia coli actin homolog MreB, which is essential for the maintenance of rod-like cell shape in bacteria. We find that MreB rotates around the long axis of the cell in a persistent manner. Whereas previous studies have suggested that MreB dynamics are driven by its own polymerization, we show that MreB rotation does not depend on its own polymerization but rather requires the assembly of the peptidoglycan cell wall. The cell-wall synthesis machinery thus either constitutes a novel type of extracellular motor that exerts force on cytoplasmic MreB, or is indirectly required for an as-yet-unidentified motor. Biophysical simulations suggest that one function of MreB rotation is to ensure a uniform distribution of new peptidoglycan insertion sites, a necessary condition to maintain rod shape during growth. These findings both broaden the view of cytoskeletal motors and deepen our understanding of the physical basis of bacterial morphogenesis.

  20. An early cytoplasmic step of peptidoglycan synthesis is associated to MreB in Bacillus subtilis.

    Science.gov (United States)

    Rueff, Anne-Stéphanie; Chastanet, Arnaud; Domínguez-Escobar, Julia; Yao, Zhizhong; Yates, James; Prejean, Maria-Victoria; Delumeau, Olivier; Noirot, Philippe; Wedlich-Söldner, Roland; Filipe, Sergio R; Carballido-López, Rut

    2014-01-01

    MreB proteins play a major role during morphogenesis of rod-shaped bacteria by organizing biosynthesis of the peptidoglycan cell wall. However, the mechanisms underlying this process are not well understood. In Bacillus subtilis, membrane-associated MreB polymers have been shown to be associated to elongation-specific complexes containing transmembrane morphogenetic factors and extracellular cell wall assembly proteins. We have now found that an early intracellular step of cell wall synthesis is also associated to MreB. We show that the previously uncharacterized protein YkuR (renamed DapI) is required for synthesis of meso-diaminopimelate (m-DAP), an essential constituent of the peptidoglycan precursor, and that it physically interacts with MreB. Highly inclined laminated optical sheet microscopy revealed that YkuR forms uniformly distributed foci that exhibit fast motion in the cytoplasm, and are not detected in cells lacking MreB. We propose a model in which soluble MreB organizes intracellular steps of peptidoglycan synthesis in the cytoplasm to feed the membrane-associated cell wall synthesizing machineries. © 2013 John Wiley & Sons Ltd.

  1. The actin-like MreB proteins in Bacillus subtilis: a new turn.

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    Chastanet, Arnaud; Carballido-Lopez, Rut

    2012-06-01

    A decade ago, two breakthrough descriptions were reported: 1) the first helix-like protein localization pattern of MreB and its paralog Mbl in Bacillus subtilis and 2) the crystal structure of Thermotoga maritima MreB1, which was remarkably similar to that of actin. These discoveries strongly stimulated the field of bacterial development, leading to the identification of many new cytoskeletal proteins (1) and the publication of many studies describing the helical patterns of protein, DNA and even lipid domains. However, today, new breakthroughs are shaking up what had become a dogma. Instead of helical structures, MreBs appear to form discrete patches that move circumferentially around the cell, questioning the idea of MreB cables forming an actin-like cytoskeleton. Furthermore, increasing evidence of biochemical properties that are unlike the properties of actin suggest that the molecular behavior of MreB proteins may be different. The aim of this review is to summarize the current knowledge of the so-called "actin-like" MreB cytoskeleton through a discussion of the model Gram-positive bacterium B. subtilis and the most recent findings in this rapidly evolving research field.

  2. Multiple Arginine Residues Are Methylated in Drosophila Mre11 and Required for Survival Following Ionizing Radiation.

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    Yuan, Qing; Tian, Ran; Zhao, Haiying; Li, Lijuan; Bi, Xiaolin

    2018-05-31

    Mre11 is a key player for DNA double strand break repair. Previous studies have shown that mammalian Mre11 is methylated at multiple arginines in its C-terminal Glycine-Arginine-Rich motif (GAR) by protein arginine methyltransferase PRMT1. Here, we found that the Drosophila Mre11 is methylated at arginines 559, 563, 565, and 569 in the GAR motif by DART1, the Drosophila homolog of PRMT1. Mre11 interacts with DART1 in S2 cells, and this interaction does not require the GAR motif. Arginines methylated Mre11 localizes exclusively in the nucleus as soluble nuclear protein or chromatin-binding protein. To study the in vivo functions of methylation, we generated the single Arg-Ala and all Arginines mutated flies. We found these mutants were sensitive to ionizing radiation. Furthermore, Arg-Ala mutated flies had no irradiation induced G2/M checkpoint defect in wing disc and eye disc. Thus, we provided evidence that arginines in Drosophila Mre11 are methylated by DART1 methytransferase and flies loss of arginine methylation are sensitive to irradiation. Copyright © 2018 Yuan et al.

  3. The bacterial Sec system is required for the organization and function of the MreB cytoskeleton.

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    Govindarajan, Sutharsan; Amster-Choder, Orna

    2017-09-01

    The Sec system is responsible for protein insertion, translocation and secretion across membranes in all cells. The bacterial actin homolog MreB controls various processes, including cell wall synthesis, membrane organization and polarity establishment. Here we show that the two systems genetically interact and that components of the Sec system, especially the SecA motor protein, are essential for spatiotemporal organization of MreB in E. coli, as evidenced by the accumulation of MreB at irregular sites in Sec-impaired cells. MreB mislocalization in SecA-defective cells significantly affects MreB-coordinated processes, such as cell wall synthesis, and induce formation of membrane invaginations enriched in high fluidity domains. Additionally, MreB is not recruited to the FtsZ ring in secA mutant cells, contributing to division arrest and cell filamentation. Our results show that all these faults are due to improper targeting of MreB to the membrane in the absence of SecA. Thus, when we reroute RodZ, MreB membrane-anchor, by fusing it to a SecA-independent integral membrane protein and overproducing it, MreB localization is restored and the defect in cell division is corrected. Notably, the RodZ moiety is not properly inserted into the membrane, strongly suggesting that it only serves as a bait for placing MreB around the cell circumference. Finally, we show that MreB localization depends on SecA also in C. crescentus, suggesting that regulation of MreB by the Sec system is conserved in bacteria. Taken together, our data reveal that the secretion system plays an important role in determining the organization and functioning of the cytoskeletal system in bacteria.

  4. Drivers of contaminant levels in surface water of China during 2000-2030: Relative importance for illustrative home and personal care product chemicals.

    Science.gov (United States)

    Zhu, Ying; Price, Oliver R; Kilgallon, John; Qi, Yi; Tao, Shu; Jones, Kevin C; Sweetman, Andrew J

    2018-03-21

    Water pollution are among the most critical problems in China and emerging contaminants in surface water have attracted rising attentions in recent years. There is great interest in China's future environmental quality as the national government has committed to a major action plan to improve surface water quality. This study presents methodologies to rank the importance of socioeconomic and environmental drivers to the chemical concentration in surface water during 2000-2030. A case study is conducted on triclosan, a home and personal care product (HPCP) ingredient. Different economic and discharge flow scenarios are considered. Urbanization and wastewater treatment connection rates in rural and urban areas are collected or projected for 2000-2030 for counties across China. The estimated usage increases from ca. 86 to 340 t. However, emissions decreases from 76 to 52 t during 2000-2030 under a modelled Organisation for Economic Co-operation (OECD) economic scenario because of the urbanization, migration and development of wastewater treatment plants/facilities (WWTPs). The estimated national median concentration of triclosan ranges 1.5-8.2 ng/L during 2000-2030 for different scenarios. It peaks in 2009 under the OECD and three of the Intergovernmental Panel on Climate Change (IPCC), A2, B1 and B2 economic scenarios, but in 2025 under A1 economic scenario. Population distribution and surface water discharge flow rates are ranked as the top two drivers to triclosan levels in surface water over the 30 years. The development of urban WWTPs was the most important driver during 2000-2010 and the development of rural works is projected to be the most important in 2011-2030. Projections suggest discharges of ingredients in HPCPs - controlled by economic growth - should be balanced by the major expenditure programme on wastewater treatment in China. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Motion of variable-length MreB filaments at the bacterial cell membrane influences cell morphology.

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    Reimold, Christian; Defeu Soufo, Herve Joel; Dempwolff, Felix; Graumann, Peter L

    2013-08-01

    The maintenance of rod-cell shape in many bacteria depends on actin-like MreB proteins and several membrane proteins that interact with MreB. Using superresolution microscopy, we show that at 50-nm resolution, Bacillus subtilis MreB forms filamentous structures of length up to 3.4 μm underneath the cell membrane, which run at angles diverging up to 40° relative to the cell circumference. MreB from Escherichia coli forms at least 1.4-μm-long filaments. MreB filaments move along various tracks with a maximal speed of 85 nm/s, and the loss of ATPase activity leads to the formation of extended and static filaments. Suboptimal growth conditions lead to formation of patch-like structures rather than extended filaments. Coexpression of wild-type MreB with MreB mutated in the subunit interface leads to formation of shorter MreB filaments and a strong effect on cell shape, revealing a link between filament length and cell morphology. Thus MreB has an extended-filament architecture with the potential to position membrane proteins over long distances, whose localization in turn may affect the shape of the cell wall.

  6. Regulation of cell wall morphogenesis in Bacillus subtilis by recruitment of PBP1 to the MreB helix.

    Science.gov (United States)

    Kawai, Yoshikazu; Daniel, Richard A; Errington, Jeffery

    2009-03-01

    The bacterial actin homologue MreB plays a key role in cell morphogenesis. In Bacillus subtilis MreB is essential under normal growth conditions and mreB mutants are defective in the control of cell diameter. However, the precise role of MreB is still unclear. Analysis of the lethal phenotypic consequences of mreB disruption revealed an unusual bulging phenotype that precedes cell death. A similar phenotype was seen in wild-type cells at very low Mg(2+) concentrations. We found that inactivation of the major bi-functional penicillin-binding protein (PBP) PBP1 of B. subtilis restored the viability of an mreB null mutant as well as preventing bulging in both mutant and wild-type backgrounds. Bulging was associated with delocalization of PBP1. We show that the normal pattern of localization of PBP1 is dependent on MreB and that the proteins can physically interact using in vivo pull-down and bacterial two-hybrid approaches. Interactions between MreB and several other PBPs were also detected. Our results suggest that MreB filaments associate directly with the peptidoglycan biosynthetic machinery in B. subtilis as part of the mechanism that brings about controlled cell elongation.

  7. Interaction of MreB-derived antimicrobial peptides with membranes.

    Science.gov (United States)

    Saikia, Karabi; Chaudhary, Nitin

    2018-03-25

    Antimicrobial peptides are critical components of defense systems in living forms. The activity is conferred largely by the selective membrane-permeabilizing ability. In our earlier work, we derived potent antimicrobial peptides from the 9-residue long, N-terminal amphipathic helix of E. coli MreB protein. The peptides display broad-spectrum activity, killing not only Gram-positive and Gram-negative bacteria but opportunistic fungus, Candida albicans as well. These results proved that membrane-binding stretches of bacterial proteins could turn out to be self-harming when applied from outside. Here, we studied the membrane-binding and membrane-perturbing potential of these peptides. Steady-state tryptophan fluorescence studies with tryptophan extended peptides, WMreB 1-9 and its N-terminal acetylated analog, Ac-WMreB 1-9 show preferential binding to negatively-charged liposomes. Both the peptides cause permeabilization of E. coli inner and outer-membranes. Tryptophan-lacking peptides, though permeabilize the outer-membrane efficiently, little permeabilization of the inner-membrane is observed. These data attest membrane-destabilization as the mechanism of rapid bacterial killing. This study is expected to motivate the research in identifying microbes' self-sequences to combat them. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Estimating carbon flux phenology with satellite-derived land surface phenology and climate drivers for different biomes: a synthesis of AmeriFlux observations.

    Directory of Open Access Journals (Sweden)

    Wenquan Zhu

    Full Text Available Carbon Flux Phenology (CFP can affect the interannual variation in Net Ecosystem Exchange (NEE of carbon between terrestrial ecosystems and the atmosphere. In this study, we proposed a methodology to estimate CFP metrics with satellite-derived Land Surface Phenology (LSP metrics and climate drivers for 4 biomes (i.e., deciduous broadleaf forest, evergreen needleleaf forest, grasslands and croplands, using 159 site-years of NEE and climate data from 32 AmeriFlux sites and MODIS vegetation index time-series data. LSP metrics combined with optimal climate drivers can explain the variability in Start of Carbon Uptake (SCU by more than 70% and End of Carbon Uptake (ECU by more than 60%. The Root Mean Square Error (RMSE of the estimations was within 8.5 days for both SCU and ECU. The estimation performance for this methodology was primarily dependent on the optimal combination of the LSP retrieval methods, the explanatory climate drivers, the biome types, and the specific CFP metric. This methodology has a potential for allowing extrapolation of CFP metrics for biomes with a distinct and detectable seasonal cycle over large areas, based on synoptic multi-temporal optical satellite data and climate data.

  9. Translation elongation factor EF-Tu modulates filament formation of actin-like MreB protein in vitro.

    Science.gov (United States)

    Defeu Soufo, Hervé Joël; Reimold, Christian; Breddermann, Hannes; Mannherz, Hans G; Graumann, Peter L

    2015-04-24

    EF-Tu has been shown to interact with actin-like protein MreB and to affect its localization in Escherichia coli and in Bacillus subtilis cells. We have purified YFP-MreB in an active form, which forms filaments on glass slides in vitro and was active in dynamic light-scattering assays, polymerizing in milliseconds after addition of magnesium. Purified EF-Tu enhanced the amount of MreB filaments, as seen by sedimentation assays, the speed of filament formation and the length of MreB filaments in vitro. EF-Tu had the strongest impact on MreB filaments in a 1:1 ratio, and EF-Tu co-sedimented with MreB filaments, revealing a stoichiometric interaction between both proteins. This was supported by cross-linking assays where 1:1 species were well detectable. When expressed in E. coli cells, B. subtilis MreB formed filaments and induced the formation of co-localizing B. subtilis EF-Tu structures, indicating that MreB can direct the positioning of EF-Tu structures in a heterologous cell system. Fluorescence recovery after photobleaching analysis showed that MreB filaments have a higher turnover in B. subtilis cells than in E. coli cells, indicating different filament kinetics in homologous or heterologous cell systems. The data show that MreB can direct the localization of EF-Tu in vivo, which in turn positively affects the formation and dynamics of MreB filaments. Thus, EF-Tu is a modulator of the activity of a bacterial actin-like protein. Copyright © 2015. Published by Elsevier Ltd.

  10. Riboregulation of the bacterial actin-homolog MreB by DsrA small noncoding RNA.

    Science.gov (United States)

    Cayrol, Bastien; Fortas, Emilie; Martret, Claire; Cech, Grzegorz; Kloska, Anna; Caulet, Stephane; Barbet, Marion; Trépout, Sylvain; Marco, Sergio; Taghbalout, Aziz; Busi, Florent; Wegrzyn, Grzegorz; Arluison, Véronique

    2015-01-01

    The bacterial actin-homolog MreB is a key player in bacterial cell-wall biosynthesis and is required for the maintenance of the rod-like morphology of Escherichia coli. However, how MreB cellular levels are adjusted to growth conditions is poorly understood. Here, we show that DsrA, an E. coli small noncoding RNA (sRNA), is involved in the post-transcriptional regulation of mreB. DsrA is required for the downregulation of MreB cellular concentration during environmentally induced slow growth-rates, mainly growth at low temperature and during the stationary phase. DsrA interacts in an Hfq-dependent manner with the 5' region of mreB mRNA, which contains signals for translation initiation and thereby affects mreB translation and stability. Moreover, as DsrA is also involved in the regulation of two transcriptional regulators, σ(S) and the nucleoid associated protein H-NS, which negatively regulate mreB transcription, it also indirectly contributes to mreB transcriptional down-regulation. By using quantitative analyses, our results evidence the complexity of this regulation and the tangled interplay between transcriptional and post-transcriptional control. As transcription factors and sRNA-mediated post-transcriptional regulators use different timescales, we propose that the sRNA pathway helps to adapt to changes in temperature, but also indirectly mediates long-term regulation of MreB concentration. The tight regulation and fine-tuning of mreB gene expression in response to cellular stresses is discussed in regard to the effect of the MreB protein on cell elongation.

  11. Filament formation of the Escherichia coli actin-related protein, MreB, in fission yeast.

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    Srinivasan, Ramanujam; Mishra, Mithilesh; Murata-Hori, Maki; Balasubramanian, Mohan K

    2007-02-06

    Proteins structurally related to eukaryotic actins have recently been identified in several prokaryotic organisms. These actin-like proteins (MreB and ParM) and the deviant Walker A ATPase (SopA) play a key role in DNA segregation and assemble into polymers in vitro and in vivo. MreB also plays a role in cellular morphogenesis. Whereas the dynamic properties of eukaryotic actins have been extensively characterized, those of bacterial actins are only beginning to emerge. We have established the fission yeast Schizosaccharomyces pombe as a cellular model for the functional analysis of the Escherichia coli actin-related protein MreB. We show that MreB organizes into linear bundles that grow in a symmetrically bidirectional manner at 0.46 +/- 0.03 microm/min, with new monomers and/or oligomers being added along the entire length of the bundle. Organization of linear arrays was dependent on the ATPase activity of MreB, and their alignment along the cellular long axis was achieved by sliding along the cortex of the cylindrical part of the cell. The cell ends appeared to provide a physical barrier for bundle elongation. These experiments provide new insights into the mechanism of assembly and organization of the bacterial actin cytoskeleton.

  12. Bacterial translation elongation factor EF-Tu interacts and colocalizes with actin-like MreB protein.

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    Defeu Soufo, Hervé Joël; Reimold, Christian; Linne, Uwe; Knust, Tobias; Gescher, Johannes; Graumann, Peter L

    2010-02-16

    We show that translation initiation factor EF-Tu plays a second important role in cell shape maintenance in the bacterium Bacillus subtilis. EF-Tu localizes in a helical pattern underneath the cell membrane and colocalizes with MreB, an actin-like cytoskeletal element setting up rod cell shape. The localization of MreB and of EF-Tu is interdependent, but in contrast to the dynamic MreB filaments, EF-Tu structures are more static and may serve as tracks for MreB filaments. In agreement with this idea, EF-Tu and MreB interact in vivo and in vitro. Lowering of the EF-Tu levels had a minor effect on translation but a strong effect on cell shape and on the localization of MreB, and blocking of the function of EF-Tu in translation did not interfere with the localization of MreB, showing that, directly or indirectly, EF-Tu affects the cytoskeletal MreB structure and thus serves two important functions in a bacterium.

  13. Chlamydia co-opts the rod shape-determining proteins MreB and Pbp2 for cell division.

    Science.gov (United States)

    Ouellette, Scot P; Karimova, Gouzel; Subtil, Agathe; Ladant, Daniel

    2012-07-01

    Chlamydiae are obligate intracellular bacterial pathogens that have extensively reduced their genome in adapting to the intracellular environment. The chlamydial genome contains only three annotated cell division genes and lacks ftsZ. How this obligate intracellular pathogen divides is uncharacterized. Chlamydiae contain two high-molecular-weight (HMW) penicillin binding proteins (Pbp) implicated in peptidoglycan synthesis, Pbp2 and Pbp3/FtsI. We show here, using HMW Pbp-specific penicillin derivatives, that both Pbp2 and Pbp3 are essential for chlamydial cell division. Ultrastructural analyses of antibiotic-treated cultures revealed distinct phenotypes: Pbp2 inhibition induced internal cell bodies within a single outer membrane whereas Pbp3 inhibition induced elongated phenotypes with little internal division. Each HMW Pbp interacts with the Chlamydia cell division protein FtsK. Chlamydiae are coccoid yet contain MreB, a rod shape-determining protein linked to Pbp2 in bacilli. Using MreB-specific antibiotics, we show that MreB is essential for chlamydial growth and division. Importantly, co-treatment with MreB-specific and Pbp-specific antibiotics resulted in the MreB-inhibited phenotype, placing MreB upstream of Pbp function in chlamydial cell division. Finally, we showed that MreB also interacts with FtsK. We propose that, in Chlamydia, MreB acts as a central co-ordinator at the division site to substitute for the lack of FtsZ in this bacterium. © 2012 Blackwell Publishing Ltd.

  14. Novel protein interactions with an actin homolog (MreB) of Helicobacter pylori determined by bacterial two-hybrid system.

    Science.gov (United States)

    Zepeda Gurrola, Reyna Cristina; Fu, Yajuan; Rodríguez Luna, Isabel Cristina; Benítez Cardoza, Claudia Guadalupe; López López, María de Jesús; López Vidal, Yolanda; Gutíerrez, Germán Rubén Aguilar; Rodríguez Pérez, Mario A; Guo, Xianwu

    2017-08-01

    The bacterium Helicobacter pylori infects more than 50% of the world population and causes several gastroduodenal diseases, including gastric cancer. Nevertheless, we still need to explore some protein interactions that may be involved in pathogenesis. MreB, an actin homolog, showed some special characteristics in previous studies, indicating that it could have different functions. Protein functions could be realized via protein-protein interactions. In the present study, the MreB protein from H. pylori 26695 fused with two tags 10×His and GST in tandem was overexpressed and purified from Escherchia coli. The purified recombinant protein was used to perform a pull-down assay with H. pylori 26695 cell lysate. The pulled-down proteins were identified by mass spectrometry (MALDI-TOF), in which the known important proteins related to morphogenesis were absent but several proteins related to pathogenesis process were observed. The bacterial two-hybrid system was further used to evaluate the protein interactions and showed that new interactions of MreB respectively with VacA, UreB, HydB, HylB and AddA were confirmed but the interaction MreB-MreC was not validated. These results indicated that the protein MreB in H. pylori has a distinct interactome, does not participate in cell morphogenesis via MreB-MreC but could be related to pathogenesis. Copyright © 2017 Elsevier GmbH. All rights reserved.

  15. Effects of polymerization and nucleotide identity on the conformational dynamics of the bacterial actin homolog MreB.

    Science.gov (United States)

    Colavin, Alexandre; Hsin, Jen; Huang, Kerwyn Casey

    2014-03-04

    The assembly of protein filaments drives many cellular processes, from nucleoid segregation, growth, and division in single cells to muscle contraction in animals. In eukaryotes, shape and motility are regulated through cycles of polymerization and depolymerization of actin cytoskeletal networks. In bacteria, the actin homolog MreB forms filaments that coordinate the cell-wall synthesis machinery to regulate rod-shaped growth and contribute to cellular stiffness through unknown mechanisms. Like actin, MreB is an ATPase and requires ATP to polymerize, and polymerization promotes nucleotide hydrolysis. However, it is unclear whether other similarities exist between MreB and actin because the two proteins share low sequence identity and have distinct cellular roles. Here, we use all-atom molecular dynamics simulations to reveal surprising parallels between MreB and actin structural dynamics. We observe that MreB exhibits actin-like polymerization-dependent structural changes, wherein polymerization induces flattening of MreB subunits, which restructures the nucleotide-binding pocket to favor hydrolysis. MreB filaments exhibited nucleotide-dependent intersubunit bending, with hydrolyzed polymers favoring a straighter conformation. We use steered simulations to demonstrate a coupling between intersubunit bending and the degree of flattening of each subunit, suggesting cooperative bending along a filament. Taken together, our results provide molecular-scale insight into the diversity of structural states of MreB and the relationships among polymerization, hydrolysis, and filament properties, which may be applicable to other members of the broad actin family.

  16. Multiple kernel SVR based on the MRE for remote sensing water depth fusion detection

    Science.gov (United States)

    Wang, Jinjin; Ma, Yi; Zhang, Jingyu

    2018-03-01

    Remote sensing has an important means of water depth detection in coastal shallow waters and reefs. Support vector regression (SVR) is a machine learning method which is widely used in data regression. In this paper, SVR is used to remote sensing multispectral bathymetry. Aiming at the problem that the single-kernel SVR method has a large error in shallow water depth inversion, the mean relative error (MRE) of different water depth is retrieved as a decision fusion factor with single kernel SVR method, a multi kernel SVR fusion method based on the MRE is put forward. And taking the North Island of the Xisha Islands in China as an experimentation area, the comparison experiments with the single kernel SVR method and the traditional multi-bands bathymetric method are carried out. The results show that: 1) In range of 0 to 25 meters, the mean absolute error(MAE)of the multi kernel SVR fusion method is 1.5m,the MRE is 13.2%; 2) Compared to the 4 single kernel SVR method, the MRE of the fusion method reduced 1.2% (1.9%) 3.4% (1.8%), and compared to traditional multi-bands method, the MRE reduced 1.9%; 3) In 0-5m depth section, compared to the single kernel method and the multi-bands method, the MRE of fusion method reduced 13.5% to 44.4%, and the distribution of points is more concentrated relative to y=x.

  17. Defining ATM-Independent Functions of the Mre11 Complex with a Novel Mouse Model.

    Science.gov (United States)

    Balestrini, Alessia; Nicolas, Laura; Yang-Lott, Katherine; Guryanova, Olga A; Levine, Ross L; Bassing, Craig H; Chaudhuri, Jayanta; Petrini, John H J

    2016-02-01

    The Mre11 complex (Mre11, Rad50, and Nbs1) occupies a central node of the DNA damage response (DDR) network and is required for ATM activation in response to DNA damage. Hypomorphic alleles of MRE11 and NBS1 confer embryonic lethality in ATM-deficient mice, indicating that the complex exerts ATM-independent functions that are essential when ATM is absent. To delineate those functions, a conditional ATM allele (ATM(flox)) was crossed to hypomorphic NBS1 mutants (Nbs1(ΔB/ΔB) mice). Nbs1(ΔB/ΔB) Atm(-/-) hematopoietic cells derived by crossing to vav(cre) were viable in vivo. Nbs1(ΔB/ΔB) Atm(-/-) (VAV) mice exhibited a pronounced defect in double-strand break repair and completely penetrant early onset lymphomagenesis. In addition to repair defects observed, fragile site instability was noted, indicating that the Mre11 complex promotes genome stability upon replication stress in vivo. The data suggest combined influences of the Mre11 complex on DNA repair, as well as the responses to DNA damage and DNA replication stress. A novel mouse model was developed, by combining a vav(cre)-inducible ATM knockout mouse with an NBS1 hypomorphic mutation, to analyze ATM-independent functions of the Mre11 complex in vivo. These data show that the DNA repair, rather than DDR signaling functions of the complex, is acutely required in the context of ATM deficiency to suppress genome instability and lymphomagenesis. ©2015 American Association for Cancer Research.

  18. Zaštita računarskih mreža / Protection of computer networks

    Directory of Open Access Journals (Sweden)

    Milojko Jevtović

    2005-09-01

    Full Text Available U radu su obrađene metode napada, oblici ugrožavanja i vrste pretnji kojima su izložene računarske mreže, kao i moguće metode i tehnička rešenja za zaštitu mreža. Analizirani su efekti pretnji kojima mogu biti izložene računarske mreže i informacije koje se preko njih prenose. Opisana su određena tehnička rešenja koja obezbeđuju potreban nivo zaštite računarskih mreža, kao i mere za zaštitu informacija koje se preko njih prenose. Navedeni su standardi koji se odnose na metode i procedure kriptozaštite informacija u računarskim mrežama. U radu je naveden primer zaštite jedne lokalne računarske mreže. / In this paper different methods of attacks, threats and different forms of dangers to the computer networks are described. The possible models and technical solutions for networks protection are also given. The effects of threats directed to the computer networks and their information are analyzed certain technical solutions that provide necessary protection level of the computer networks as well as measures for information protection are also described. The standards for methods and security procedure for the information in computer networks are enlisted. There is also an example of protecting one local data network (in this paper.

  19. Wavelet Adaptive Algorithm and Its Application to MRE Noise Control System

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    Zhang Yulin

    2015-01-01

    Full Text Available To address the limitation of conventional adaptive algorithm used for active noise control (ANC system, this paper proposed and studied two adaptive algorithms based on Wavelet. The twos are applied to a noise control system including magnetorheological elastomers (MRE, which is a smart viscoelastic material characterized by a complex modulus dependent on vibration frequency and controllable by external magnetic fields. Simulation results reveal that the Decomposition LMS algorithm (D-LMS and Decomposition and Reconstruction LMS algorithm (DR-LMS based on Wavelet can significantly improve the noise reduction performance of MRE control system compared with traditional LMS algorithm.

  20. Preslikavanje parametara kvaliteta usluga na protokole ATM mreža

    OpenAIRE

    Milojko Jevtović

    2005-01-01

    Preslikavanje parametara kvaliteta usluga (Quality of Service - QoS) jedan je od bitnih elemenata u koncepciji ATM (Asynchronous Transfer Mode) širokopojasnih mreža. U radu su opisani parametri QoS-a (verovatnoće pogrešnih ramova i ćelija, propusni opseg, kašnjenje ćelija, varijacija kašnjenja) koji se preslikavaju na protokole ATM mreža. Preslikavanje se izvodi između korisničkog i aplikacionog QoS-a, a aplikacioni QoS se preslikava na QoS prenosa i komutacije, odnosno na ATM protokole, tzv....

  1. Utjecaj napona mreže na karakteristiku momenta kaveznog asinkronog motora

    OpenAIRE

    Vusić, Mario

    2017-01-01

    Ovim radom prikazan je utjecaj napona mreže na momentnu karakteristiku kaveznog asinkronog motora, odnosno njegove vanjske karakteristike. Provedeni su pokusi ispitivanja kaveznog asinkronog motora kako bi se utvrdili parametri nadomjesne sheme. Dobiveni su parametri potom korišteni za računalnu simulaciju zaleta motora direktnim uključivanjem na mrežu u programskom paketu Matlab Simulink. Također proveden je i pokus zaleta asinkronog kaveznog motora u laboratoriju za električne strojeve ...

  2. Rad50S alleles of the Mre11 complex: questions answered and questions raised.

    Science.gov (United States)

    Usui, Takehiko; Petrini, John H J; Morales, Monica

    2006-08-15

    We find that Rad50S mutations in yeast and mammals exhibit constitutive PIKK (PI3-kinase like kinase)-dependent signaling [T. Usui, H. Ogawa, J.H. Petrini, A DNA damage response pathway controlled by Tel1 and the Mre11 complex. Mol. Cell 7 (2001) 1255-1266.; M. Morales, J.W. Theunissen, C.F. Kim, R. Kitagawa, M.B. Kastan, J.H. Petrini, The Rad50S allele promotes ATM-dependent DNA damage responses and suppresses ATM deficiency: implications for the Mre11 complex as a DNA damage sensor. Genes Dev. 19 (2005) 3043-4354.]. The signaling depends on Mre11 complex functions, consistent with its role as a DNA damage sensor. Rad50S is distinct from hypomorphic mutations of Mre11 and Nbs1 in mammals [M. Morales, J.W. Theunissen, C.F. Kim, R. Kitagawa, M.B. Kastan, J.H. Petrini, The Rad50S allele promotes ATM-dependent DNA damage responses and suppresses ATM deficiency: implications for the Mre11 complex as a DNA damage sensor. Genes Dev. 19 (2005) 3043-3054.; J.P. Carney, R.S. Maser, H. Olivares, E.M. Davis, Le M. Beau, J.R. Yates, III, L. Hays, W.F. Morgan, J.H. Petrini, The hMre11/hRad50 protein complex and Nijmegen breakage syndrome: linkage of double-strand break repair to the cellular DNA damage response. Cell 93 (1998) 477-486.; G.S. Stewart, R.S. Maser, T. Stankovic, D.A. Bressan, M.I. Kaplan, N.G. Jaspers, A. Raams, P.J. Byrd, J.H. Petrini, A.M. Taylor, The DNA double-strand break repair gene hMRE11 is mutated in individuals with an ataxia-telangiectasia-like disorder. Cell 99 (1999) 577-587.; B.R. Williams, O.K. Mirzoeva, W.F. Morgan, J. Lin, W. Dunnick, J.H. Petrini, A murine model of nijmegen breakage syndrome. Curr. Biol. 12 (2002) 648-653.; J.W. Theunissen, M.I. Kaplan, P.A. Hunt, B.R. Williams, D.O. Ferguson, F.W. Alt, J.H. Petrini, Checkpoint failure and chromosomal instability without lymphomagenesis in Mre11(ATLD1/ATLD1) mice. Mol. Cell 12 (2003) 1511-1523.] and the Mre11 complex deficiency in yeast [T. Usui, H. Ogawa, J.H. Petrini, A DNA damage response

  3. The physical characteristics of the French MRE zones. Focus on the tidal turbine sites. PP presentations

    International Nuclear Information System (INIS)

    Jambu, Emilie; Laporte, Patrice; Garlan, Thierry; Le Boulluec, Marc; Germain, Gregory; Michel, Sylvain; Belan, Pierre-Yves

    2014-04-01

    This document gathers Power Point presentations which were contributions to a workshop on French sites of marine renewable energies (MRE). A first one presents the production potential of tidal energy sites in Basse-Normandie, and how favourable areas are defined. The second one reports works performed by the SHOM to characterize the physical marine environment of French MRE sites (SHOM missions, objectives, knowledge on tidal currents, 3D current models, location of current meters offshore Cotentin and the Iroise Sea). The next contribution discusses the relationship between MREs and sedimentology in the case of different offshore wind farms and tidal energy sites. A contribution addresses modelling based on the HOMERE database (Hydrodynamics Ocean-Meteorology and Marine Renewable Energies). The next one presents programmes undertaken by the French Agency of Protected Marine Areas for a better knowledge of the natural patrimony of MRE sites. The last contribution presents the CEREMA, the development of a geographical information system to plan MRE sites, and information activities

  4. Differentiated roles for MreB-actin isologues and autolytic enzymes in Bacillus subtilis morphogenesis.

    Science.gov (United States)

    Domínguez-Cuevas, Patricia; Porcelli, Ida; Daniel, Richard A; Errington, Jeff

    2013-09-01

    Cell morphogenesis in most bacteria is governed by spatiotemporal growth regulation of the peptidoglycan cell wall layer. Much is known about peptidoglycan synthesis but regulation of its turnover by hydrolytic enzymes is much less well understood. Bacillus subtilis has a multitude of such enzymes. Two of the best characterized are CwlO and LytE: cells lacking both enzymes have a lethal block in cell elongation. Here we show that activity of CwlO is regulated by an ABC transporter, FtsEX, which is required for cell elongation, unlike cell division as in Escherichia coli. Actin-like MreB proteins are thought to play a key role in orchestrating cell wall morphogenesis. B. subtilis has three MreB isologues with partially differentiated functions. We now show that the three MreB isologues have differential roles in regulation of the CwlO and LytE systems and that autolysins control different aspects of cell morphogenesis. The results add major autolytic activities to the growing list of functions controlled by MreB isologues in bacteria and provide new insights into the different specialized functions of essential cell wall autolysins. © 2013 The Authors. Molecular Microbiology published by John Wiley & Sons Ltd.

  5. Bacterial actin MreB assembles in complex with cell shape protein RodZ.

    Science.gov (United States)

    van den Ent, Fusinita; Johnson, Christopher M; Persons, Logan; de Boer, Piet; Löwe, Jan

    2010-03-17

    Bacterial actin homologue MreB is required for cell shape maintenance in most non-spherical bacteria, where it assembles into helical structures just underneath the cytoplasmic membrane. Proper assembly of the actin cytoskeleton requires RodZ, a conserved, bitopic membrane protein that colocalises to MreB and is essential for cell shape determination. Here, we present the first crystal structure of bacterial actin engaged with a natural partner and provide a clear functional significance of the interaction. We show that the cytoplasmic helix-turn-helix motif of Thermotoga maritima RodZ directly interacts with monomeric as well as filamentous MreB and present the crystal structure of the complex. In vitro and in vivo analyses of mutant T. maritima and Escherichia coli RodZ validate the structure and reveal the importance of the MreB-RodZ interaction in the ability of cells to propagate as rods. Furthermore, the results elucidate how the bacterial actin cytoskeleton might be anchored to the membrane to help constrain peptidoglycan synthesis in the periplasm.

  6. MRE11 complex links RECQ5 helicase to sites of DNA damage

    Czech Academy of Sciences Publication Activity Database

    Zheng, L.; Kanagaraj, R.; Mihaljevic, B.; Schwendener, S.; Sartori, A.A.; Gerrits, B.; Shevelev, Igor; Janščák, Pavel

    2009-01-01

    Roč. 37, č. 8 (2009), s. 2645-2657 ISSN 0305-1048 R&D Projects: GA ČR GA204/09/0565 Institutional research plan: CEZ:AV0Z50520514 Keywords : homologous recombination, * RECQ5 helicase * MRE11 * DNA repair Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 7.479, year: 2009

  7. An innovative MRE absorber with double natural frequencies for wide frequency bandwidth vibration absorption

    International Nuclear Information System (INIS)

    Sun, Shuaishuai; Yang, Jian; Li, Weihua; Alici, Gursel; Deng, Huaxia; Du, Haiping; Yan, Tianhong

    2016-01-01

    A new design of adaptive tuned vibration absorber was proposed in this study for vibration reduction. The innovation of the new absorber is the adoption of the eccentric mass on the top of the multilayered magnetorheological elastomer (MRE) structure so that this proposed absorber has two vibration modes: one in the torsional direction and the other in translational direction. This property enables the absorber to expand its effective bandwidth and to be more capable of reducing the vibrations especially dealing with those vibrations with multi-frequencies. The innovative MRE absorber was designed and tested on a horizontal vibration table. The test results illustrate that the MRE absorber realized double natural frequencies, both of which are controllable. Inertia’s influence on the dynamic behavior of the absorber is also investigated in order to guide the design of the innovative MRE absorber. Additionally, the experimentally obtained natural frequencies coincide with the theoretical data, which sufficiently verifies the feasibility of this new design. The last part in terms of the vibration absorption ability also proves that both of these two natural frequencies play a great role in absorbing vibration energy. (paper)

  8. Requirement of the Mre11 complex and exonuclease 1 for activation of the Mec1 signaling pathway.

    Science.gov (United States)

    Nakada, Daisuke; Hirano, Yukinori; Sugimoto, Katsunori

    2004-11-01

    The large protein kinases, ataxia-telangiectasia mutated (ATM) and ATM-Rad3-related (ATR), orchestrate DNA damage checkpoint pathways. In budding yeast, ATM and ATR homologs are encoded by TEL1 and MEC1, respectively. The Mre11 complex consists of two highly related proteins, Mre11 and Rad50, and a third protein, Xrs2 in budding yeast or Nbs1 in mammals. The Mre11 complex controls the ATM/Tel1 signaling pathway in response to double-strand break (DSB) induction. We show here that the Mre11 complex functions together with exonuclease 1 (Exo1) in activation of the Mec1 signaling pathway after DNA damage and replication block. Mec1 controls the checkpoint responses following UV irradiation as well as DSB induction. Correspondingly, the Mre11 complex and Exo1 play an overlapping role in activation of DSB- and UV-induced checkpoints. The Mre11 complex and Exo1 collaborate in producing long single-stranded DNA (ssDNA) tails at DSB ends and promote Mec1 association with the DSBs. The Ddc1-Mec3-Rad17 complex associates with sites of DNA damage and modulates the Mec1 signaling pathway. However, Ddc1 association with DSBs does not require the function of the Mre11 complex and Exo1. Mec1 controls checkpoint responses to stalled DNA replication as well. Accordingly, the Mre11 complex and Exo1 contribute to activation of the replication checkpoint pathway. Our results provide a model in which the Mre11 complex and Exo1 cooperate in generating long ssDNA tracts and thereby facilitate Mec1 association with sites of DNA damage or replication block.

  9. Dynamic localization and interaction with other Bacillus subtilis actin-like proteins are important for the function of MreB.

    Science.gov (United States)

    Defeu Soufo, Hervé Joël; Graumann, Peter L

    2006-12-01

    Bacterial actin-like proteins play a key role in cell morphology and in chromosome segregation. Many bacteria, like Bacillus subtilis, contain three genes encoding actin-like proteins, called mreB, mbl and mreBH in B. subtilis. We show that MreB and Mbl colocalize extensively within live cells, and that all three B. subtilis actin paralogues interact with each other underneath the cell membrane. A mutation in the phosphate 2 motif of MreB had a dominant negative effect on cell morphology and on chromosome segregation. Expression of this mutant allele of MreB interfered with the dynamic localization of Mbl. These experiments show that the interaction between MreB and Mbl has physiological significance. An mreB deletion strain can grow under special media conditions, however, depletion of Mbl in this mutant background abolished growth, indicating that actin paralogues can partially complement each other. The membrane protein MreC was found to interact with Mbl, but not with MreB, revealing a clear distinction between the function of the two paralogues. The phosphate 2 mutant MreB protein allowed for filament formation of mutant or wild-type MreB, but abolished the dynamic reorganization of the filaments. The latter mutation led to a strong reduction, but not complete loss, of function of MreB, both in terms of chromosome segregation and of cell morphology. Our work shows that that the dynamic localization of MreB is essential for the proper activity of the actin-like protein and that the interactions between MreB paralogues have important physiological significance.

  10. PBP deletion mutants of Escherichia coli exhibit irregular distribution of MreB at the deformed zones.

    Science.gov (United States)

    Vijayan, Saptha; Mallick, Sathi; Dutta, Mouparna; Narayani, M; Ghosh, Anindya S

    2014-02-01

    MreB is a cytoskeletal protein, which is responsible for maintaining proper cellular morphology and is essential for cell survival. Likewise, penicillin-binding protein 5 (PBP5) helps in maintaining cell shape, though non-essential for survival. The contradicting feature of these two proteins paves the way for this study, wherein we attempt to draw a relation on the nature of distribution of MreB in PBP deletion mutants. The study revealed that the uniform MreB helices/patches were destabilized/disturbed at the zone of deformities of the PBP mutants, whereas the helical patterns were retained at the regions maintaining a rod shape. We interpret that MreB remains functional irrespective of its distribution being misguided by the aberrant shapes of PBP mutants.

  11. Drivers and Effects of Groundwater-Surface Water Interaction in the Karstic Lower Flint River Basin, Southwestern Georgia, USA

    Science.gov (United States)

    Rugel, K.; Golladay, S. W.; Jackson, C. R.; Rasmussen, T. C.; Dowd, J. F.; Mcdowell, R. J.

    2017-12-01

    Groundwater provides the majority of global water resources for domestic and agricultural usage while contributing vital surface water baseflows which support healthy aquatic ecosystems. Understanding the extent and magnitude of hydrologic connectivity between groundwater and surface water components in karst watersheds is essential to the prudent management of these hydraulically-interactive systems. We examined groundwater and surface water connectivity between the Upper Floridan Aquifer (UFA) and streams in the Lower Flint River Basin (LFRB) in southwestern Georgia where development of agricultural irrigation intensified over the past 30 years. An analysis of USGS streamflow data for the pre- and post-irrigation period showed summer baseflows in some Lower Flint River tributaries were reduced by an order of magnitude in the post-irrigation period, reiterating the strong hydraulic connection between these streams and the underlying aquifer. Large and fine-scale monitoring of calcium, nitrate, specific conductance and stable isotopes (δ18O and δD) on 50 km of Ichawaynochaway Creek, a major tributary of the Lower Flint, detected discrete groundwater-surface water flow paths which accounted for 42% of total groundwater contributions in the 50 km study reach. This presentation will highlight a new analysis using the metadata EPA Reach File (1) and comparing stream reach and instream bedrock joint azimuths with stream geochemical results from previous field study. Our findings suggested that reaches with NNW bearing may be more likely to display enhanced groundwater-surface water connectivity. Our results show that local heterogeneity can significantly affect water budgets and quality within these watersheds, making the use of geomorphological stream attributes a valuable tool to water resource management for the prediction and protection of vulnerable regions of hydrologic connectivity in karst catchments.

  12. MRE: a web tool to suggest foreign enzymes for the biosynthesis pathway design with competing endogenous reactions in mind

    KAUST Repository

    Kuwahara, Hiroyuki; Alazmi, Meshari; Cui, Xuefeng; Gao, Xin

    2016-01-01

    To rationally design a productive heterologous biosynthesis system, it is essential to consider the suitability of foreign reactions for the specific endogenous metabolic infrastructure of a host. We developed a novel web server, called MRE, which, for a given pair of starting and desired compounds in a given chassis organism, ranks biosynthesis routes from the perspective of the integration of new reactions into the endogenous metabolic system. For each promising heterologous biosynthesis pathway, MRE suggests actual enzymes for foreign metabolic reactions and generates information on competing endogenous reactions for the consumption of metabolites. These unique, chassis-centered features distinguish MRE from existing pathway design tools and allow synthetic biologists to evaluate the design of their biosynthesis systems from a different angle. By using biosynthesis of a range of high-value natural products as a case study, we show that MRE is an effective tool to guide the design and optimization of heterologous biosynthesis pathways. The URL of MRE is http://www.cbrc.kaust.edu.sa/mre/.

  13. MRE: a web tool to suggest foreign enzymes for the biosynthesis pathway design with competing endogenous reactions in mind

    KAUST Repository

    Kuwahara, Hiroyuki

    2016-04-29

    To rationally design a productive heterologous biosynthesis system, it is essential to consider the suitability of foreign reactions for the specific endogenous metabolic infrastructure of a host. We developed a novel web server, called MRE, which, for a given pair of starting and desired compounds in a given chassis organism, ranks biosynthesis routes from the perspective of the integration of new reactions into the endogenous metabolic system. For each promising heterologous biosynthesis pathway, MRE suggests actual enzymes for foreign metabolic reactions and generates information on competing endogenous reactions for the consumption of metabolites. These unique, chassis-centered features distinguish MRE from existing pathway design tools and allow synthetic biologists to evaluate the design of their biosynthesis systems from a different angle. By using biosynthesis of a range of high-value natural products as a case study, we show that MRE is an effective tool to guide the design and optimization of heterologous biosynthesis pathways. The URL of MRE is http://www.cbrc.kaust.edu.sa/mre/.

  14. Modelling hydrological changes in surface in relation with anthropogenic drivers and consequences on human health and local economic

    Science.gov (United States)

    Sandoz, Alain; Leblond, Agnès; Boutron, Olivier

    2016-04-01

    of the watershed. The modeling also performed to simulate a change in rainfall locally to measure hydrological and environmental consequences. According to these scenarios, it was possible to map the potential areas of mosquitoes breeding sites (presence / absence of mosquitoes) and their impact on urban populations in terms of health risks and nuisance. This territory represents many interests for decision-makers interested in issues of governance and renaturation. To improve the inclusion of better water governance and territories, as well as facilitate dynamic annealing, it might be necessary to help decision-makers having a better knowledge of the impact of human drivers on water management on the territory. This increased knowledge would also enable local decision-makers to improve their awareness of the heritage and biodiversity of wetlands. This project was funded by the French Ministry of Ecology, Sustainable Development and Energy as part of the projects Water and Territories.

  15. Reconstruction of mreB expression in Staphylococcus aureus via a collection of new integrative plasmids.

    Science.gov (United States)

    Yepes, Ana; Koch, Gudrun; Waldvogel, Andrea; Garcia-Betancur, Juan-Carlos; Lopez, Daniel

    2014-07-01

    Protein localization has been traditionally explored in unicellular organisms, whose ease of genetic manipulation facilitates molecular characterization. The two rod-shaped bacterial models Escherichia coli and Bacillus subtilis have been prominently used for this purpose and have displaced other bacteria whose challenges for genetic manipulation have complicated any study of cell biology. Among these bacteria is the spherical pathogenic bacterium Staphylococcus aureus. In this report, we present a new molecular toolbox that facilitates gene deletion in staphylococci in a 1-step recombination process and additional vectors that facilitate the insertion of diverse reporter fusions into newly identified neutral loci of the S. aureus chromosome. Insertion of the reporters does not add any antibiotic resistance genes to the chromosomes of the resultant strains, thereby making them amenable for further genetic manipulations. We used this toolbox to reconstitute the expression of mreB in S. aureus, a gene that encodes an actin-like cytoskeletal protein which is absent in coccal cells and is presumably lost during the course of speciation. We observed that in S. aureus, MreB is organized in discrete structures in association with the membrane, leading to an unusual redistribution of the cell wall material. The production of MreB also caused cell enlargement, but it did not revert staphylococcal shape. We present interactions of MreB with key staphylococcal cell wall-related proteins. This work facilitates the use S. aureus as a model system in exploring diverse aspects of cellular microbiology. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  16. Mre11-Sae2 and RPA Collaborate to Prevent Palindromic Gene Amplification.

    Science.gov (United States)

    Deng, Sarah K; Yin, Yi; Petes, Thomas D; Symington, Lorraine S

    2015-11-05

    Foldback priming at DNA double-stranded breaks is one mechanism proposed to initiate palindromic gene amplification, a common feature of cancer cells. Here, we show that small (5-9 bp) inverted repeats drive the formation of large palindromic duplications, the major class of chromosomal rearrangements recovered from yeast cells lacking Sae2 or the Mre11 nuclease. RPA dysfunction increased the frequency of palindromic duplications in Sae2 or Mre11 nuclease-deficient cells by ∼ 1,000-fold, consistent with intra-strand annealing to create a hairpin-capped chromosome that is subsequently replicated to form a dicentric isochromosome. The palindromic duplications were frequently associated with duplication of a second chromosome region bounded by a repeated sequence and a telomere, suggesting the dicentric chromosome breaks and repairs by recombination between dispersed repeats to acquire a telomere. We propose secondary structures within single-stranded DNA are potent instigators of genome instability, and RPA and Mre11-Sae2 play important roles in preventing their formation and propagation, respectively. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. A feasibility work on the applications of MRE to automotive components

    Science.gov (United States)

    Kim, S. H.; Park, Y. J.; Cha, A. R.; Kim, G. W.; Bang, J. H.; Lim, C. S.; Choi, S. B.

    2018-03-01

    A feasibility work on the application of magneto-rheological elastomers (MREs) to automotive components, such as engine mounts is presented. While vehicle components require the high resonance frequency in terms of ride quality and handling, it is required to have the low resonance frequency to isolate the incoming vibration. With the conventional automotive technologies, it is challenging to combine these two conflicting performance trade-offs, ride quality including handling, and NVH (noise, vibration and harshness). Over the last decades, MREs, one of the new emerging smart materials, have been widely used to resolve this technical limitation. For example, an advanced engine mount was developed by using MRE to isolate the vibration transmitting from engines. In this paper, we will focus on rear cross member bushes, which is a key component for isolating the vibration from the road, and demonstrate their improved performance by utilizing MRE. The resonance frequency shift induced by the stiffness change of MRE will be presented through the frequency response functions estimated by simulation result.

  18. A theory for narrow-banded radio bursts at Uranus - MHD surface waves as an energy driver

    Science.gov (United States)

    Farrell, W. M.; Curtis, S. A.; Desch, M. D.; Lepping, R. P.

    1992-01-01

    A possible scenario for the generation of the narrow-banded radio bursts detected at Uranus by the Voyager 2 planetary radio astronomy experiment is described. In order to account for the emission burstiness which occurs on time scales of hundreds of milliseconds, it is proposed that ULF magnetic surface turbulence generated at the frontside magnetopause propagates down the open/closed field line boundary and mode-converts to kinetic Alfven waves (KAW) deep within the polar cusp. The oscillating KAW potentials then drive a transient electron stream that creates the bursty radio emission. To substantiate these ideas, Voyager 2 magnetometer measurements of enhanced ULF magnetic activity at the frontside magnetopause are shown. It is demonstrated analytically that such magnetic turbulence should mode-convert deep in the cusp at a radial distance of 3 RU.

  19. RodZ promotes MreB polymer formation and curvature localization to determine the cylindrical uniformity of E. coli shape

    OpenAIRE

    Bratton, Benjamin; Morgenstein, Randy; Shaevitz, Joshua; Gitai, Zemer

    2017-01-01

    Cell shape in bacteria is determined by the cell wall, which is synthesized by a variety of proteins whose actions are coordinated by the actin-like MreB protein. MreB uses local geometric cues of envelope curvature to avoid the cell poles and localize to specific regions of the cell body. However, it remains unclear whether MreB's curvature preference is regulated by additional factors, and which features of MreB are essential for specific aspects of rod shape growth, such as cylindrical uni...

  20. Differential conformational modulations of MreB folding upon interactions with GroEL/ES and TRiC chaperonin components

    Science.gov (United States)

    Moparthi, Satish Babu; Carlsson, Uno; Vincentelli, Renaud; Jonsson, Bengt-Harald; Hammarström, Per; Wenger, Jérôme

    2016-01-01

    Here, we study and compare the mechanisms of action of the GroEL/GroES and the TRiC chaperonin systems on MreB client protein variants extracted from E. coli. MreB is a homologue to actin in prokaryotes. Single-molecule fluorescence correlation spectroscopy (FCS) and time-resolved fluorescence polarization anisotropy report the binding interaction of folding MreB with GroEL, GroES and TRiC. Fluorescence resonance energy transfer (FRET) measurements on MreB variants quantified molecular distance changes occurring during conformational rearrangements within folding MreB bound to chaperonins. We observed that the MreB structure is rearranged by a binding-induced expansion mechanism in TRiC, GroEL and GroES. These results are quantitatively comparable to the structural rearrangements found during the interaction of β-actin with GroEL and TRiC, indicating that the mechanism of chaperonins is conserved during evolution. The chaperonin-bound MreB is also significantly compacted after addition of AMP-PNP for both the GroEL/ES and TRiC systems. Most importantly, our results showed that GroES may act as an unfoldase by inducing a dramatic initial expansion of MreB (even more than for GroEL) implicating a role for MreB folding, allowing us to suggest a delivery mechanism for GroES to GroEL in prokaryotes. PMID:27328749

  1. Localization Microscopy Analyses of MRE11 Clusters in 3D-Conserved Cell Nuclei of Different Cell Lines

    Directory of Open Access Journals (Sweden)

    Marion Eryilmaz

    2018-01-01

    Full Text Available In radiation biophysics, it is a subject of nowadays research to investigate DNA strand break repair in detail after damage induction by ionizing radiation. It is a subject of debate as to what makes up the cell’s decision to use a certain repair pathway and how the repair machinery recruited in repair foci is spatially and temporarily organized. Single-molecule localization microscopy (SMLM allows super-resolution analysis by precise localization of single fluorescent molecule tags, resulting in nuclear structure analysis with a spatial resolution in the 10 nm regime. Here, we used SMLM to study MRE11 foci. MRE11 is one of three proteins involved in the MRN-complex (MRE11-RAD50-NBS1 complex, a prominent DNA strand resection and broken end bridging component involved in homologous recombination repair (HRR and alternative non-homologous end joining (a-NHEJ. We analyzed the spatial arrangements of antibody-labelled MRE11 proteins in the nuclei of a breast cancer and a skin fibroblast cell line along a time-course of repair (up to 48 h after irradiation with a dose of 2 Gy. Different kinetics for cluster formation and relaxation were determined. Changes in the internal nano-scaled structure of the clusters were quantified and compared between the two cell types. The results indicate a cell type-dependent DNA damage response concerning MRE11 recruitment and cluster formation. The MRE11 data were compared to H2AX phosphorylation detected by γH2AX molecule distribution. These data suggested modulations of MRE11 signal frequencies that were not directly correlated to DNA damage induction. The application of SMLM in radiation biophysics offers new possibilities to investigate spatial foci organization after DNA damaging and during subsequent repair.

  2. Localization Microscopy Analyses of MRE11 Clusters in 3D-Conserved Cell Nuclei of Different Cell Lines.

    Science.gov (United States)

    Eryilmaz, Marion; Schmitt, Eberhard; Krufczik, Matthias; Theda, Franziska; Lee, Jin-Ho; Cremer, Christoph; Bestvater, Felix; Schaufler, Wladimir; Hausmann, Michael; Hildenbrand, Georg

    2018-01-22

    In radiation biophysics, it is a subject of nowadays research to investigate DNA strand break repair in detail after damage induction by ionizing radiation. It is a subject of debate as to what makes up the cell's decision to use a certain repair pathway and how the repair machinery recruited in repair foci is spatially and temporarily organized. Single-molecule localization microscopy (SMLM) allows super-resolution analysis by precise localization of single fluorescent molecule tags, resulting in nuclear structure analysis with a spatial resolution in the 10 nm regime. Here, we used SMLM to study MRE11 foci. MRE11 is one of three proteins involved in the MRN-complex (MRE11-RAD50-NBS1 complex), a prominent DNA strand resection and broken end bridging component involved in homologous recombination repair (HRR) and alternative non-homologous end joining (a-NHEJ). We analyzed the spatial arrangements of antibody-labelled MRE11 proteins in the nuclei of a breast cancer and a skin fibroblast cell line along a time-course of repair (up to 48 h) after irradiation with a dose of 2 Gy. Different kinetics for cluster formation and relaxation were determined. Changes in the internal nano-scaled structure of the clusters were quantified and compared between the two cell types. The results indicate a cell type-dependent DNA damage response concerning MRE11 recruitment and cluster formation. The MRE11 data were compared to H2AX phosphorylation detected by γH2AX molecule distribution. These data suggested modulations of MRE11 signal frequencies that were not directly correlated to DNA damage induction. The application of SMLM in radiation biophysics offers new possibilities to investigate spatial foci organization after DNA damaging and during subsequent repair.

  3. Functional Interplay of the Mre11 Nuclease and Ku in the Response to Replication-Associated DNA Damage ▿

    Science.gov (United States)

    Foster, Steven S.; Balestrini, Alessia; Petrini, John H. J.

    2011-01-01

    The Mre11 complex is a central component of the DNA damage response, with roles in damage sensing, molecular bridging, and end resection. We have previously shown that in Saccharomyces cerevisiae, Ku70 (yKu70) deficiency reduces the ionizing radiation sensitivity of mre11Δ mutants. In this study, we show that yKu70 deficiency suppressed the camptothecin (CPT) and methyl methanesulfonate (MMS) sensitivity of nuclease-deficient mre11-3 and sae2Δ mutants in an Exo1-dependent manner. CPT-induced G2/M arrest, γ-H2AX persistence, and chromosome breaks were elevated in mre11-3 mutants. These outcomes were reduced by yKu70 deficiency. Given that the genotoxic effects of CPT are manifest during DNA replication, these data suggest that Ku limits Exo1-dependent double-strand break (DSB) resection during DNA replication, inhibiting the initial processing steps required for homology-directed repair. We propose that Mre11 nuclease- and Sae2-dependent DNA end processing, which initiates DSB resection prevents Ku from engaging DSBs, thus promoting Exo1-dependent resection. In agreement with this idea, we show that Ku affinity for binding to short single-stranded overhangs is much lower than for blunt DNA ends. Collectively, the data define a nonhomologous end joining (NHEJ)-independent, S-phase-specific function of the Ku heterodimer. PMID:21876003

  4. Bacterial motility complexes require the actin-like protein, MreB and the Ras homologue, MglA.

    Science.gov (United States)

    Mauriello, Emilia M F; Mouhamar, Fabrice; Nan, Beiyan; Ducret, Adrien; Dai, David; Zusman, David R; Mignot, Tâm

    2010-01-20

    Gliding motility in the bacterium Myxococcus xanthus uses two motility engines: S-motility powered by type-IV pili and A-motility powered by uncharacterized motor proteins and focal adhesion complexes. In this paper, we identified MreB, an actin-like protein, and MglA, a small GTPase of the Ras superfamily, as essential for both motility systems. A22, an inhibitor of MreB cytoskeleton assembly, reversibly inhibited S- and A-motility, causing rapid dispersal of S- and A-motility protein clusters, FrzS and AglZ. This suggests that the MreB cytoskeleton is involved in directing the positioning of these proteins. We also found that a DeltamglA motility mutant showed defective localization of AglZ and FrzS clusters. Interestingly, MglA-YFP localization mimicked both FrzS and AglZ patterns and was perturbed by A22 treatment, consistent with results indicating that both MglA and MreB bind to motility complexes. We propose that MglA and the MreB cytoskeleton act together in a pathway to localize motility proteins such as AglZ and FrzS to assemble the A-motility machineries. Interestingly, M. xanthus motility systems, like eukaryotic systems, use an actin-like protein and a small GTPase spatial regulator.

  5. Molecular evolution of the actin-like MreB protein gene family in wall-less bacteria.

    Science.gov (United States)

    Ku, Chuan; Lo, Wen-Sui; Kuo, Chih-Horng

    2014-04-18

    The mreB gene family encodes actin-like proteins that determine cell shape by directing cell wall synthesis and often exists in one to three copies in the genomes of non-spherical bacteria. Intriguingly, while most wall-less bacteria do not have this gene, five to seven mreB homologs are found in Spiroplasma and Haloplasma, which are both characterized by cell contractility. To investigate the molecular evolution of this gene family in wall-less bacteria, we sampled the available genome sequences from these two genera and other related lineages for comparative analysis. The gene phylogenies indicated that the mreB homologs in Haloplasma are more closely related to those in Firmicutes, whereas those in Spiroplasma form a separate clade. This finding suggests that the gene family expansions in these two lineages are the results of independent ancient duplications. Moreover, the Spiroplasma mreB homologs can be classified into five clades, of which the genomic positions are largely conserved. The inference of gene gains and losses suggests that there has been an overall trend to retain only one homolog from each of the five mreB clades in the evolutionary history of Spiroplasma. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  6. The small G-protein MglA connects to the MreB actin cytoskeleton at bacterial focal adhesions.

    Science.gov (United States)

    Treuner-Lange, Anke; Macia, Eric; Guzzo, Mathilde; Hot, Edina; Faure, Laura M; Jakobczak, Beata; Espinosa, Leon; Alcor, Damien; Ducret, Adrien; Keilberg, Daniela; Castaing, Jean Philippe; Lacas Gervais, Sandra; Franco, Michel; Søgaard-Andersen, Lotte; Mignot, Tâm

    2015-07-20

    In Myxococcus xanthus the gliding motility machinery is assembled at the leading cell pole to form focal adhesions, translocated rearward to propel the cell, and disassembled at the lagging pole. We show that MglA, a Ras-like small G-protein, is an integral part of this machinery. In this function, MglA stimulates the assembly of the motility complex by directly connecting it to the MreB actin cytoskeleton. Because the nucleotide state of MglA is regulated spatially and MglA only binds MreB in the guanosine triphosphate-bound form, the motility complexes are assembled at the leading pole and dispersed at the lagging pole where the guanosine triphosphatase activating protein MglB disrupts the MglA-MreB interaction. Thus, MglA acts as a nucleotide-dependent molecular switch to regulate the motility machinery spatially. The function of MreB in motility is independent of its function in peptidoglycan synthesis, representing a coopted function. Our findings highlight a new function for the MreB cytoskeleton and suggest that G-protein-cytoskeleton interactions are a universally conserved feature. © 2015 Treuner-Lange et al.

  7. Germline variants in MRE11/RAD50/NBN complex genes in childhood leukemia

    International Nuclear Information System (INIS)

    Mosor, Maria; Ziółkowska-Suchanek, Iwona; Nowicka, Karina; Dzikiewicz-Krawczyk, Agnieszka; Januszkiewicz–Lewandowska, Danuta; Nowak, Jerzy

    2013-01-01

    The MRE11, RAD50, and NBN genes encode proteins of the MRE11-RAD50-NBN (MRN) complex involved in cellular response to DNA damage and the maintenance of genome stability. In our previous study we showed that the germline p.I171V mutation in NBN may be considered as a risk factor in the development of childhood acute lymphoblastic leukemia (ALL) and some specific haplotypes of that gene may be associated with childhood leukemia. These findings raise important questions about the role of mutations in others genes of the MRN complex in childhood leukemia. The aim of this study was to answer the question whether MRE11 and RAD50 alterations may be associated with childhood ALL or AML. We estimated the frequency of constitutional mutations and polymorphisms in selected regions of MRE11, RAD50, and NBN in the group of 220 children diagnosed with childhood leukemias and controls (n=504/2200). The analysis was performed by specific amplification of region of interest by PCR and followed by multi-temperature single-strand conformation polymorphism (PCR-MSSCP) technique. We performed two molecular tests to examine any potential function of the detected the c.551+19G>A SNP in RAD50 gene. To our knowledge, this is the first analysis of the MRE11, RAD50 and NBN genes in childhood leukemia. The frequency of either the AA genotype or A allele of RAD50-rs17166050 were significantly different in controls compared to leukemia group (ALL+AML) (p<0.0019 and p<0.0019, respectively). The cDNA analysis of AA or GA genotypes carriers has not revealed evidence of splicing abnormality of RAD50 pre-mRNA. We measured the allelic-specific expression of G and A alleles at c.551+19G>A and the statistically significant overexpression of the G allele has been observed. Additionally we confirmed the higher incidence of the p.I171V mutation in the leukemia group (7/220) than among controls (12/2400) (p<0.0001). The formerly reported sequence variants in the RAD50 and MRE11 gene may not constitute a

  8. The role of the Mre11–Rad50–Nbs1 complex in double-strand break repair—facts and myths

    International Nuclear Information System (INIS)

    Takeda, Shunichi; Hoa, Nguyen Ngoc; Sasanuma, Hiroyuki

    2016-01-01

    Homologous recombination (HR) initiates double-strand break (DSB) repair by digesting 5′-termini at DSBs, the biochemical reaction called DSB resection, during which DSBs are processed by nucleases to generate 3′ single-strand DNA. Rad51 recombinase polymerizes along resected DNA, and the resulting Rad51–DNA complex undergoes homology search. Although DSB resection by the Mre11 nuclease plays a critical role in HR in Saccharomyces cerevisiae, it remains elusive whether DSB resection by Mre11 significantly contributes to HR-dependent DSB repair in mammalian cells. Depletion of Mre11 decreases the efficiency of DSB resection only by 2- to 3-fold in mammalian cells. We show that although Mre11 is required for efficient HR-dependent repair of ionizing-radiation–induced DSBs, Mre11 is largely dispensable for DSB resection in both chicken DT40 and human TK6 B cell lines. Moreover, a 2- to 3-fold decrease in DSB resection has virtually no impact on the efficiency of HR. Thus, although a large number of researchers have reported the vital role of Mre11-mediated DSB resection in HR, the role may not explain the very severe defect in HR in Mre11-deficient cells, including their lethality. We here show experimental evidence for the additional roles of Mre11 in (i) elimination of chemical adducts from DSB ends for subsequent DSB repair, and (ii) maintaining HR intermediates for their proper resolution

  9. E3 Ligase cIAP2 Mediates Downregulation of MRE11 and Radiosensitization in Response to HDAC Inhibition in Bladder Cancer.

    Science.gov (United States)

    Nicholson, Judith; Jevons, Sarah J; Groselj, Blaz; Ellermann, Sophie; Konietzny, Rebecca; Kerr, Martin; Kessler, Benedikt M; Kiltie, Anne E

    2017-06-01

    The MRE11/RAD50/NBS1 (MRN) complex mediates DNA repair pathways, including double-strand breaks induced by radiotherapy. Meiotic recombination 11 homolog (MRE11) is downregulated by histone deacetylase inhibition (HDACi), resulting in reduced levels of DNA repair in bladder cancer cells and radiosensitization. In this study, we show that the mechanism of this downregulation is posttranslational and identify a C-terminally truncated MRE11, which is formed after HDAC inhibition as full-length MRE11 is downregulated. Truncated MRE11 was stabilized by proteasome inhibition, exhibited a decreased half-life after treatment with panobinostat, and therefore represents a newly identified intermediate induced and degraded in response to HDAC inhibition. The E3 ligase cellular inhibitor of apoptosis protein 2 (cIAP2) was upregulated in response to HDAC inhibition and was validated as a new MRE11 binding partner whose upregulation had similar effects to HDAC inhibition. cIAP2 overexpression resulted in downregulation and altered ubiquitination patterns of MRE11 and mediated radiosensitization in response to HDAC inhibition. These results highlight cIAP2 as a player in the DNA damage response as a posttranscriptional regulator of MRE11 and identify cIAP2 as a potential target for biomarker discovery or chemoradiation strategies in bladder cancer. Cancer Res; 77(11); 3027-39. ©2017 AACR . ©2017 American Association for Cancer Research.

  10. YodL and YisK Possess Shape-Modifying Activities That Are Suppressed by Mutations in Bacillus subtilis mreB and mbl.

    Science.gov (United States)

    Duan, Yi; Sperber, Anthony M; Herman, Jennifer K

    2016-08-01

    Many bacteria utilize actin-like proteins to direct peptidoglycan (PG) synthesis. MreB and MreB-like proteins are thought to act as scaffolds, guiding the localization and activity of key PG-synthesizing proteins during cell elongation. Despite their critical role in viability and cell shape maintenance, very little is known about how the activity of MreB family proteins is regulated. Using a Bacillus subtilis misexpression screen, we identified two genes, yodL and yisK, that when misexpressed lead to loss of cell width control and cell lysis. Expression analysis suggested that yodL and yisK are previously uncharacterized Spo0A-regulated genes, and consistent with these observations, a ΔyodL ΔyisK mutant exhibited reduced sporulation efficiency. Suppressors resistant to YodL's killing activity occurred primarily in mreB mutants and resulted in amino acid substitutions at the interface between MreB and the highly conserved morphogenic protein RodZ, whereas suppressors resistant to YisK occurred primarily in mbl mutants and mapped to Mbl's predicted ATP-binding pocket. YodL's shape-altering activity appears to require MreB, as a ΔmreB mutant was resistant to the effects of YodL but not YisK. Similarly, YisK appears to require Mbl, as a Δmbl mutant was resistant to the cell-widening effects of YisK but not of YodL. Collectively, our results suggest that YodL and YisK likely modulate MreB and Mbl activity, possibly during the early stages of sporulation. The peptidoglycan (PG) component of the cell envelope confers structural rigidity to bacteria and protects them from osmotic pressure. MreB and MreB-like proteins are thought to act as scaffolds for PG synthesis and are essential in bacteria exhibiting nonpolar growth. Despite the critical role of MreB-like proteins, we lack mechanistic insight into how their activities are regulated. Here, we describe the discovery of two B. subtilis proteins, YodL and YisK, which modulate MreB and Mbl activities. Our data suggest

  11. The North Atlantic marine reservoir effect in the Early Holocene: Implications for defining and understanding MRE values

    Energy Technology Data Exchange (ETDEWEB)

    Ascough, P.L. [School of Geography and Geosciences, Irvine Building, University of St. Andrews, St. Andrews, Fife KY16 9AL (United Kingdom)]. E-mail: pla1@st-andrews.ac.uk; Cook, G.T. [Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, Rankine Avenue, East Kilbride G75 OQF (United Kingdom); Dugmore, A.J. [Institute of Geography, School of GeoSciences, University of Edinburgh, Edinburgh EH8 9XP (United Kingdom); Scott, E.M. [Department of Statistics, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

    2007-06-15

    The marine reservoir effect (MRE) is a {sup 14}C age offset between the oceanic and atmospheric carbon reservoirs. The MRE is neither spatially nor temporally constant and values may deviate significantly from the global model average provided by the Marine04 curve. Such a deviation is calculated as a {delta}R value and modern (pre-bomb) values show considerable spatial variations. There is also considerable evidence for temporal variability linked to paleoenvironmental changes identified in paleoclimatic proxy records. Seven new {delta}R values are presented for the North Atlantic, relating to the period c. 8430-3890 cal. BP (c. 6480-1940 BC). These were obtained from {sup 14}C analysis of multiple samples of terrestrial and marine material derived from seven individual archaeological deposits from Mainland Scotland, the Outer Hebrides and the Orkney Isles. The {delta}R values vary between 143 {+-} 20 {sup 14}C yr and -100 {+-} 15 {sup 14}C yr with the positive values all occurring in the earlier period (8430-5060 cal. BP), and the negative values all coming from later deposits (4820-3890 cal. BP). The nature of MRE values and the potential for spatial and temporal variation in values is the subject of current research interest and these data are placed in the context of (i) other estimates for UK coastal waters and (ii) important questions concerning current approaches to quantifying the MRE.

  12. Superresolution imaging of dynamic MreB filaments in B. subtilis--a multiple-motor-driven transport?

    Science.gov (United States)

    Olshausen, Philipp V; Defeu Soufo, Hervé Joël; Wicker, Kai; Heintzmann, Rainer; Graumann, Peter L; Rohrbach, Alexander

    2013-09-03

    The cytoskeletal protein MreB is an essential component of the bacterial cell-shape generation system. Using a superresolution variant of total internal reflection microscopy with structured illumination, as well as three-dimensional stacks of deconvolved epifluorescence microscopy, we found that inside living Bacillus subtilis cells, MreB forms filamentous structures of variable lengths, typically not longer than 1 μm. These filaments move along their orientation and mainly perpendicular to the long bacterial axis, revealing a maximal velocity at an intermediate length and a decreasing velocity with increasing filament length. Filaments move along straight trajectories but can reverse or alter their direction of propagation. Based on our measurements, we provide a mechanistic model that is consistent with all observations. In this model, MreB filaments mechanically couple several motors that putatively synthesize the cell wall, whereas the filaments' traces mirror the trajectories of the motors. On the basis of our mechanistic model, we developed a mathematical model that can explain the nonlinear velocity length dependence. We deduce that the coupling of cell wall synthesis motors determines the MreB filament transport velocity, and the filament mechanically controls a concerted synthesis of parallel peptidoglycan strands to improve cell wall stability. Copyright © 2013 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  13. Superresolution Imaging of Dynamic MreB Filaments in B. subtilis—A Multiple-Motor-Driven Transport?

    Science.gov (United States)

    Olshausen, Philipp v.; Defeu Soufo, Hervé Joël; Wicker, Kai; Heintzmann, Rainer; Graumann, Peter L.; Rohrbach, Alexander

    2013-01-01

    The cytoskeletal protein MreB is an essential component of the bacterial cell-shape generation system. Using a superresolution variant of total internal reflection microscopy with structured illumination, as well as three-dimensional stacks of deconvolved epifluorescence microscopy, we found that inside living Bacillus subtilis cells, MreB forms filamentous structures of variable lengths, typically not longer than 1 μm. These filaments move along their orientation and mainly perpendicular to the long bacterial axis, revealing a maximal velocity at an intermediate length and a decreasing velocity with increasing filament length. Filaments move along straight trajectories but can reverse or alter their direction of propagation. Based on our measurements, we provide a mechanistic model that is consistent with all observations. In this model, MreB filaments mechanically couple several motors that putatively synthesize the cell wall, whereas the filaments’ traces mirror the trajectories of the motors. On the basis of our mechanistic model, we developed a mathematical model that can explain the nonlinear velocity length dependence. We deduce that the coupling of cell wall synthesis motors determines the MreB filament transport velocity, and the filament mechanically controls a concerted synthesis of parallel peptidoglycan strands to improve cell wall stability. PMID:24010660

  14. Realizacija računarske mreže vojnomedicinske akademije / Medical military academy information system management

    Directory of Open Access Journals (Sweden)

    Miroslav Stojanović

    2005-01-01

    Full Text Available Vojnomedicinska akademija (VMA u Beogradu danas se ne može zamisliti bez kvalitetnog informacionog sistema, koji se najčešće razvija u sistemu računarske mreže. Cilj ovoga rada je da prikaže smernice i definiše neka rešenja u implementaciji buduće računarske mreže VMA. Težište rada je na implementaciji prva tri nivoa OSI modela jedne složene i kompleksne mreže kakva bi trebalo da bude računarska mreža VMA. / The Medical Military Academy (MMA in Belgrade cannot be imagined without a high-quality information system implemented in a corresponding computer network. The aim of this study is to show guidelines and possible solutions in implementing a computer network in to the MMA in the future. The main part of this study describes the implementation of the first three levels of the OSI model into the complex MMA computer network.

  15. In Escherichia coli, MreB and FtsZ direct the synthesis of lateral cell wall via independent pathways that require PBP 2.

    Science.gov (United States)

    Varma, Archana; Young, Kevin D

    2009-06-01

    In Escherichia coli, the cytoplasmic proteins MreB and FtsZ play crucial roles in ensuring that new muropeptide subunits are inserted into the cell wall in a spatially correct way during elongation and division. In particular, to retain a constant diameter and overall shape, new material must be inserted into the wall uniformly around the cell's perimeter. Current thinking is that MreB accomplishes this feat through intermediary proteins that tether peptidoglycan synthases to the outer face of the inner membrane. We tested this idea in E. coli by using a DD-carboxypeptidase mutant that accumulates pentapeptides in its peptidoglycan, allowing us to visualize new muropeptide incorporation. Surprisingly, inhibiting MreB with the antibiotic A22 did not result in uneven insertion of new wall, although the cells bulged and lost their rod shapes. Instead, uneven (clustered) incorporation occurred only if MreB and FtsZ were inactivated simultaneously, providing the first evidence in E. coli that FtsZ can direct murein incorporation into the lateral cell wall independently of MreB. Inhibiting penicillin binding protein 2 (PBP 2) alone produced the same clustered phenotype, implying that MreB and FtsZ tether peptidoglycan synthases via a common mechanism that includes PBP 2. However, cell shape was determined only by the presence or absence of MreB and not by the even distribution of new wall material as directed by FtsZ.

  16. Mimivirus reveals Mre11/Rad50 fusion proteins with a sporadic distribution in eukaryotes, bacteria, viruses and plasmids

    Directory of Open Access Journals (Sweden)

    Ogata Hiroyuki

    2011-09-01

    Full Text Available Abstract Background The Mre11/Rad50 complex and the homologous SbcD/SbcC complex in bacteria play crucial roles in the metabolism of DNA double-strand breaks, including DNA repair, genome replication, homologous recombination and non-homologous end-joining in cellular life forms and viruses. Here we investigated the amino acid sequence of the Mimivirus R555 gene product, originally annotated as a Rad50 homolog, and later shown to have close homologs in marine microbial metagenomes. Results Our bioinformatics analysis revealed that R555 protein sequence is constituted from the fusion of an N-terminal Mre11-like domain with a C-terminal Rad50-like domain. A systematic database search revealed twelve additional cases of Mre11/Rad50 (or SbcD/SbcC fusions in a wide variety of unrelated organisms including unicellular and multicellular eukaryotes, the megaplasmid of a bacterium associated to deep-sea hydrothermal vents (Deferribacter desulfuricans and the plasmid of Clostridium kluyveri. We also showed that R555 homologs are abundant in the metagenomes from different aquatic environments and that they most likely belong to aquatic viruses. The observed phyletic distribution of these fusion proteins suggests their recurrent creation and lateral gene transfers across organisms. Conclusions The existence of the fused version of protein sequences is consistent with known functional interactions between Mre11 and Rad50, and the gene fusion probably enhanced the opportunity for lateral transfer. The abundance of the Mre11/Rad50 fusion genes in viral metagenomes and their sporadic phyletic distribution in cellular organisms suggest that viruses, plasmids and transposons played a crucial role in the formation of the fusion proteins and their propagation into cellular genomes.

  17. Examination of Supplemental Driver Training and Online Basic Driver Education

    Science.gov (United States)

    2012-06-01

    This report describes supplemental driver training programs and online basic driver education. It coves supplemental driver training that : focused on knowledge and skills beyond those normally found in traditional driver education delivered in the U...

  18. Evaluating Older Drivers' Skills

    Science.gov (United States)

    2013-05-01

    Research has demonstrated that older drivers pose a higher risk of involvement in fatal crashes at intersections than : younger drivers. Age-triggered restrictions are problematic as research shows that the majority of older people : have unimpaired ...

  19. Online driver's license renewal.

    Science.gov (United States)

    2015-09-01

    The Kentucky Department of Vehicle Regulation is exploring the possibility of developing and implementing online : drivers license renewal. The objective of this project was to: 1) evaluate online drivers license and REAL ID renewal : programs ...

  20. The Role of MreB in Escherichia Coli's Cellular Rigidity

    Science.gov (United States)

    Shaevitz, Joshua W.

    2009-03-01

    Bacteria possess homologs of all three classes of eukaryotic cytoskeletal proteins. These filamentous proteins have been shown to localize proteins essential for a number of cell-biological processes in prokaryotes such as cell growth and division. However, to date, there has been no direct evidence that the cytoskeleton in bacteria bears mechanical loads or can generate physical forces than are used by the cell. I will present evidence from combined fluorescence and force microscopy measurements that MreB, an actin homolog, is responsible for half of Escherichia coli's cellular rigidity. These data support an interpretation in which the cytoskeleton, the peptidoglycan cell wall and a large turgor pressure work together to give gram-negative cells their mechanical properties.

  1. Older drivers : a review.

    NARCIS (Netherlands)

    Hakamies-Blomqvist, L. Sirén, A. & Davidse, R.J.

    2004-01-01

    The proportion of senior citizens (aged 65+) will grow from about 15 per cent in the year 2000 to about 30 per cent in the year 2050. The share of older drivers in the driver population will grow even faster because of increasing licensing rates among the ageing population. Older drivers do not have

  2. A Novel indole compound that inhibits Pseudomonas aeruginosa growth by targeting MreB is a substrate for MexAB-OprM.

    Science.gov (United States)

    Robertson, Gregory T; Doyle, Timothy B; Du, Qun; Duncan, Leonard; Mdluli, Khisimuzi E; Lynch, A Simon

    2007-10-01

    Drug efflux systems contribute to the intrinsic resistance of Pseudomonas aeruginosa to many antibiotics and biocides and hamper research focused on the discovery and development of new antimicrobial agents targeted against this important opportunistic pathogen. Using a P. aeruginosa PAO1 derivative bearing deletions of opmH, encoding an outer membrane channel for efflux substrates, and four efflux pumps belonging to the resistance nodulation/cell division class including mexAB-oprM, we identified a small-molecule indole-class compound (CBR-4830) that is inhibitory to growth of this efflux-compromised strain. Genetic studies established MexAB-OprM as the principal pump for CBR-4830 and revealed MreB, a prokaryotic actin homolog, as the proximal cellular target of CBR-4830. Additional studies establish MreB as an essential protein in P. aeruginosa, and efflux-compromised strains treated with CBR-4830 transition to coccoid shape, consistent with MreB inhibition or depletion. Resistance genetics further suggest that CBR-4830 interacts with the putative ATP-binding pocket in MreB and demonstrate significant cross-resistance with A22, a structurally unrelated compound that has been shown to promote rapid dispersion of MreB filaments in vivo. Interestingly, however, ATP-dependent polymerization of purified recombinant P. aeruginosa MreB is blocked in vitro in a dose-dependent manner by CBR-4830 but not by A22. Neither compound exhibits significant inhibitory activity against mutant forms of MreB protein that bear mutations identified in CBR-4830-resistant strains. Finally, employing the strains and reagents prepared and characterized during the course of these studies, we have begun to investigate the ability of analogues of CBR-4830 to inhibit the growth of both efflux-proficient and efflux-compromised P. aeruginosa through specific inhibition of MreB function.

  3. Morphogenes bolA and mreB mediate the photoregulation of cellular morphology during complementary chromatic acclimation in Fremyella diplosiphon.

    Science.gov (United States)

    Singh, Shailendra P; Montgomery, Beronda L

    2014-07-01

    Photoregulation of pigmentation during complementary chromatic acclimation (CCA) is well studied in Fremyella diplosiphon; however, mechanistic insights into the CCA-associated morphological changes are still emerging. F. diplosiphon cells are rectangular under green light (GL), whereas cells are smaller and spherical under red light (RL). Here, we investigate the role of morphogenes bolA and mreB during CCA using gene expression and gene function analyses. The F. diplosiphon bolA gene is essential as its complete removal from the genome was unsuccessful. Depletion of bolA resulted in slow growth, morphological defects and the accumulation of high levels of reactive oxygen species in a partially segregated ΔbolA strain. Higher expression of bolA was observed under RL and was correlated with lower expression of mreB and mreC genes in wild type. In a ΔrcaE strain that lacks the red-/green-responsive RcaE photoreceptor, the expression of bolA and mre genes was altered under both RL and GL. Observed gene expression relationships suggest that mreB and mreC expression is controlled by RcaE-dependent photoregulation of bolA expression. Expression of F. diplosiphon bolA and mreB homologues in Escherichia coli demonstrated functional conservation of the encoded proteins. Together, these studies establish roles for bolA and mreB in RcaE-dependent regulation of cellular morphology. © 2014 John Wiley & Sons Ltd.

  4. The helical MreB cytoskeleton in Escherichia coli MC1000/pLE7 is an artifact of the N-Terminal yellow fluorescent protein tag.

    Science.gov (United States)

    Swulius, Matthew T; Jensen, Grant J

    2012-12-01

    Based on fluorescence microscopy, the actin homolog MreB has been thought to form extended helices surrounding the cytoplasm of rod-shaped bacterial cells. The presence of these and other putative helices has come to dominate models of bacterial cell shape regulation, chromosome segregation, polarity, and motility. Here we use electron cryotomography to show that MreB does in fact form extended helices and filaments in Escherichia coli when yellow fluorescent protein (YFP) is fused to its N terminus but native (untagged) MreB expressed to the same levels does not. In contrast, mCherry fused to an internal loop (MreB-RFP(SW)) does not induce helices. The helices are therefore an artifact of the placement of the fluorescent protein tag. YFP-MreB helices were also clearly distinguishable from the punctate, "patchy" localization patterns of MreB-RFP(SW), even by standard light microscopy. The many interpretations in the literature of such punctate patterns as helices should therefore be reconsidered.

  5. 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

    OpenAIRE

    Defeu Soufo, Hervé Joël; Graumann, Peter L

    2005-01-01

    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 tha...

  6. Formation of covalent linkages between nuclear and protein constituents of ribosomes of E. coli MRE 600 irradiated by gamma rays

    Energy Technology Data Exchange (ETDEWEB)

    Ekert, B; Giocanti, N [Institut du Radium, 91 - Orsay (France)

    1977-04-01

    Gamma irradiation of E.coli MRE 600 ribosomes in aqueous suspensions led to covalent linkages between the RNA and some ribosomal proteins. The presence of oxygen during the irradiation strongly inhibited this phenomenon. It appears clearly that only a few proteins were able to participate in these cross-linking reactions, which occurred simultaneously in the two sub-units. The radiochemical yield was determined at several concentrations and was relatively low.

  7. National Driver Register (NDR) -

    Data.gov (United States)

    Department of Transportation — Information regarding individuals who have had their driver licenses revoked, suspended or otherwise denied for cause, or who have been convicted of certain traffic...

  8. Experimental and Analytical Research on Resonance Phenomena of Vibrating Head with MRE Regulating Element

    Science.gov (United States)

    Miedzińska, D.; Gieleta, R.; Osiński, J.

    2015-02-01

    A vibratory pile hammer (VPH) is a mechanical device used to drive steel piles as well as tube piles into soil to provide foundation support for buildings or other structures. In order to increase the stability and the efficiency of the VPH work in the over-resonance frequency, a new VPH construction was developed at the Military University of Technology. The new VPH contains a system of counter-rotating eccentric weights, powered by hydraulic motors, and designed in such a way that horizontal vibrations cancel out, while vertical vibrations are transmitted into the pile. This system is suspended in the static parts by the adaptive variable stiffness pillows based on a smart material, magnetorheological elastomer (MRE), whose rheological and mechanical properties can be reversibly and rapidly controlled by an external magnetic field. The work presented in the paper is a part of the modified VPH construction design process. It concerns the experimental research on the vibrations during the piling process and the analytical analyses of the gained signal. The results will be applied in the VPH control system.

  9. Young novice drivers.

    NARCIS (Netherlands)

    2013-01-01

    In The Netherlands, young novice drivers (18-24 years of age) show a crash rate that is five times higher than that of experienced drivers (30-59 years of age). The rate of young males is even seven times as high. The main reasons are lack of driving experience and hazardous behaviour typical of

  10. Criteria for driver impairment

    NARCIS (Netherlands)

    Brookhuis, K.A.; De Waard, D.; Fairclough, S.H

    2003-01-01

    Most traffic accidents can be attributed to driver impairment, e.g. inattention, fatigue, intoxication, etc. It is now technically feasible to monitor and diagnose driver behaviour with respect to impairment with the aid of a limited number of in-vehicle sensors. However, a valid framework for the

  11. A Simple Wave Driver

    Science.gov (United States)

    Temiz, Burak Kagan; Yavuz, Ahmet

    2015-01-01

    This study was done to develop a simple and inexpensive wave driver that can be used in experiments on string waves. The wave driver was made using a battery-operated toy car, and the apparatus can be used to produce string waves at a fixed frequency. The working principle of the apparatus is as follows: shortly after the car is turned on, the…

  12. Mre11 and Exo1 contribute to the initiation and processivity of resection at meiotic double-strand breaks made independently of Spo11.

    Science.gov (United States)

    Hodgson, Adam; Terentyev, Yaroslav; Johnson, Rebecca A; Bishop-Bailey, Anna; Angevin, Thibaut; Croucher, Adam; Goldman, Alastair S H

    2011-02-07

    During meiosis DNA double-strand breaks (DSBs) are induced and repaired by homologous recombination to create gene conversion and crossover products. Mostly these DSBs are made by Spo11, which covalently binds to the DSB ends. More rarely in Saccharomyces cerevisiae, other meiotic DSBs are formed by self-homing endonucleases such as VDE, which is site specific and does not covalently bind to the DSB ends. We have used experimentally located VDE-DSB sites to analyse an intermediate step in homologous recombination, resection of the single-strand ending 5' at the DSB site. Analysis of strains with different mutant alleles of MRE11 (mre11-58S and mre11-H125N) and deleted for EXO1 indicated that these two nucleases make significant contributions to repair of VDE-DSBs. Physical analysis of single-stranded repair intermediates indicates that efficient initiation and processivity of resection at VDE-DSBs require both Mre11 and Exo1, with loss of function for either protein causing severe delay in resection. We propose that these experiments model what happens at Spo11-DSBs after removal of the covalently bound protein, and that Mre11 and Exo1 are the major nucleases involved in creating resection tracts of widely varying lengths typical of meiotic recombination. Copyright © 2010 Elsevier B.V. All rights reserved.

  13. Virtuelne privatne mreže - moguće rešenje pouzdanih komunikacija / Virtual private networks: Possible solution of reliable communications

    Directory of Open Access Journals (Sweden)

    Marinko Smiljanić

    2008-04-01

    Full Text Available U radu su prikazane osnovne karakteristike virtuelnih privatnih mreža (VPN - Virtual Private Networks. Analizirane su VPN mreže na drugom i trećem sloju sistema otvorenog za povezivanje (OSI - Open System Interconnection. Objašnjena je realizacija internet protokola (IP - Internet Protocol VPN mreže i VPN mreže u okruženju višestruke komutacije labela (MPLS - Multi-Protocol Label Switching. Posebna pažnja posvećena je sigurnosti MPLS VPN mreža, naročito sa stanovišta upotrebe u funkcionalnim sistemima veza, kao što je sistem veza Vojske. / In this paper the basic characteristics of the VPN networks are presented. The VPN networks on the second and the third level of the OSI reference model are analyzed. The realization of the IP VPN and VPN networks within MPLS environment is presented as well. Security in MPLS networks is one of the most important characteristics, especially in military communication systems, which is shown in the second part of this paper.

  14. Chlamydia trachomatis protein CT009 is a structural and functional homolog to the key morphogenesis component RodZ and interacts with division septal plane localized MreB.

    Science.gov (United States)

    Kemege, Kyle E; Hickey, John M; Barta, Michael L; Wickstrum, Jason; Balwalli, Namita; Lovell, Scott; Battaile, Kevin P; Hefty, P Scott

    2015-02-01

    Cell division in Chlamydiae is poorly understood as apparent homologs to most conserved bacterial cell division proteins are lacking and presence of elongation (rod shape) associated proteins indicate non-canonical mechanisms may be employed. The rod-shape determining protein MreB has been proposed as playing a unique role in chlamydial cell division. In other organisms, MreB is part of an elongation complex that requires RodZ for proper function. A recent study reported that the protein encoded by ORF CT009 interacts with MreB despite low sequence similarity to RodZ. The studies herein expand on those observations through protein structure, mutagenesis and cellular localization analyses. Structural analysis indicated that CT009 shares high level of structural similarity to RodZ, revealing the conserved orientation of two residues critical for MreB interaction. Substitutions eliminated MreB protein interaction and partial complementation provided by CT009 in RodZ deficient Escherichia coli. Cellular localization analysis of CT009 showed uniform membrane staining in Chlamydia. This was in contrast to the localization of MreB, which was restricted to predicted septal planes. MreB localization to septal planes provides direct experimental observation for the role of MreB in cell division and supports the hypothesis that it serves as a functional replacement for FtsZ in Chlamydia. © 2014 John Wiley & Sons Ltd.

  15. Chlamydia trachomatis protein CT009 is a structural and functional homolog to the key morphogenesis component RodZ and interacts with division septal plane localized MreB

    Science.gov (United States)

    Kemege, Kyle E.; Hickey, John M.; Barta, Michael L.; Wickstrum, Jason; Balwalli, Namita; Lovell, Scott; Battaile, Kevin P.; Hefty, P. Scott

    2015-01-01

    Summary Cell division in Chlamydiae is poorly understood as apparent homologs to most conserved bacterial cell division proteins are lacking and presence of elongation (rod shape) associated proteins indicate non-canonical mechanisms may be employed. The rod-shape determining protein MreB has been proposed as playing a unique role in chlamydial cell division. In other organisms, MreB is part of an elongation complex that requires RodZ for proper function. A recent study reported that the protein encoded by ORF CT009 interacts with MreB despite low sequence similarity to RodZ. The studies herein expand on those observations through protein structure, mutagenesis, and cellular localization analyses. Structural analysis indicated that CT009 shares high level of structural similarity to RodZ, revealing the conserved orientation of two residues critical for MreB interaction. Substitutions eliminated MreB protein interaction and partial complementation provided by CT009 in RodZ deficient E. coli. Cellular localization analysis of CT009 showed uniform membrane staining in Chlamydia. This was in contrast to the localization of MreB, which was restricted to predicted septal planes. MreB localization to septal planes provides direct experimental observation for the role of MreB in cell division and supports the hypothesis that it serves as a functional replacement for FtsZ in Chlamydia. PMID:25382739

  16. Mek1/Mre4 is a master regulator of meiotic recombination in budding yeast

    Directory of Open Access Journals (Sweden)

    Nancy M. Hollingsworth

    2016-02-01

    Full Text Available Sexually reproducing organisms create gametes with half the somatic cell chromosome number so that fusion of gametes at fertilization does not change the ploidy of the cell. This reduction in chromosome number occurs by the specialized cell division of meiosis in which two rounds of chromosome segregation follow a single round of chromosome duplication. Meiotic crossovers formed between the non-sister chromatids of homologous chromosomes, combined with sister chromatid cohesion, physically connect homologs, thereby allowing proper segregation at the first meiotic division. Meiotic recombination is initiated by programmed double strand breaks (DSBs whose repair is highly regulated such that (1 there is a bias for recombination with homologs rather than sister chromatids, (2 crossovers are distributed throughout the genome by a process called interference, (3 crossover homeostasis regulates the balance between crossover and non-crossover repair to maintain a critical number of crossovers and (4 each pair of homologs receives at least one crossover. It was previously known that the imposition of interhomolog bias in budding yeast requires meiosis-specific modifications to the DNA damage response and the local activation of the meiosis-specific Mek1/Mre4 (hereafter Mek1 kinase at DSBs. However, because inactivation of Mek1 results in intersister, rather than interhomolog DSB repair, whether Mek1 had a role in interhomolog pathway choice was unknown. A recent study by Chen et al. (2015 reveals that Mek1 indirectly regulates the crossover/non-crossover decision between homologs as well as genetic interference. It does this by enabling phosphorylation of Zip1, the meiosis-specific transverse filament protein of the synaptonemal complex (SC, by the conserved cell cycle kinase, Cdc7-Dbf4 (DDK. These results suggest that Mek1 is a “master regulator” of meiotic recombination in budding yeast.

  17. Theoretical and Experimental Analysis of an Induction Planar Actuator with Different Secondaries—A Planar Driver Application for Metallic Surface Inspection

    Directory of Open Access Journals (Sweden)

    Felipe Treviso

    2016-03-01

    Full Text Available This paper presents a study on an induction planar actuator concept. The device uses the same principles as a linear induction motor in which the interaction between a travelling magnetic field and a conducting surface produces eddy currents that leads to the generation of a thrust force and can result in movement over a metallic surface. This can benefit the inspection of metallic surfaces based on the driving platform provided by the induction planar actuator. Equations of the magnetic and electric fields are presented and, by means of these equations, the forces involved were calculated. The behaviour of thrust and normal forces was analysed through the equations and by numerical models, and compared with the results obtained by measurements on a device prototype built in the laboratory as part of the study. With relation to the surface under inspection that forms the secondary, three cases were analysed: (1 a double-layered secondary formed by aluminium and ferromagnetic slabs; (2 a single aluminium layer and (3 a single ferromagnetic layer. Theoretical and measured values of thrust and normal forces showed good correlation.

  18. Theoretical and Experimental Analysis of an Induction Planar Actuator with Different Secondaries—A Planar Driver Application for Metallic Surface Inspection

    Science.gov (United States)

    Treviso, Felipe; Silveira, Marilia A.; Flores Filho, Aly F.; Dorrell, David G.

    2016-01-01

    This paper presents a study on an induction planar actuator concept. The device uses the same principles as a linear induction motor in which the interaction between a travelling magnetic field and a conducting surface produces eddy currents that leads to the generation of a thrust force and can result in movement over a metallic surface. This can benefit the inspection of metallic surfaces based on the driving platform provided by the induction planar actuator. Equations of the magnetic and electric fields are presented and, by means of these equations, the forces involved were calculated. The behaviour of thrust and normal forces was analysed through the equations and by numerical models, and compared with the results obtained by measurements on a device prototype built in the laboratory as part of the study. With relation to the surface under inspection that forms the secondary, three cases were analysed: (1) a double-layered secondary formed by aluminium and ferromagnetic slabs; (2) a single aluminium layer and (3) a single ferromagnetic layer. Theoretical and measured values of thrust and normal forces showed good correlation. PMID:27007377

  19. Escherichia coli DnaA forms helical structures along the longitudinal cell axis distinct from MreB filaments.

    Science.gov (United States)

    Boeneman, Kelly; Fossum, Solveig; Yang, Yanhua; Fingland, Nicholas; Skarstad, Kirsten; Crooke, Elliott

    2009-05-01

    DnaA initiates chromosomal replication in Escherichia coli at a well-regulated time in the cell cycle. To determine how the spatial distribution of DnaA is related to the location of chromosomal replication and other cell cycle events, the localization of DnaA in living cells was visualized by confocal fluorescence microscopy. The gfp gene was randomly inserted into a dnaA-bearing plasmid via in vitro transposition to create a library that included internally GFP-tagged DnaA proteins. The library was screened for the ability to rescue dnaA(ts) mutants, and a candidate gfp-dnaA was used to replace the dnaA gene of wild-type cells. The resulting cells produce close to physiological levels of GFP-DnaA from the endogenous promoter as their only source of DnaA and somewhat under-initiate replication with moderate asynchrony. Visualization of GFP-tagged DnaA in living cells revealed that DnaA adopts a helical pattern that spirals along the long axis of the cell, a pattern also seen in wild-type cells by immunofluorescence with affinity purified anti-DnaA antibody. Although the DnaA helices closely resemble the helices of the actin analogue MreB, co-visualization of GFP-tagged DnaA and RFP-tagged MreB demonstrates that DnaA and MreB adopt discrete helical structures along the length of the longitudinal cell axis.

  20. Driver behavior in traffic.

    Science.gov (United States)

    2012-02-01

    Existing traffic analysis and management tools do not model the ability of drivers to recognize their environment and respond to it with behaviors that vary according to the encountered driving situation. The small body of literature on characterizin...

  1. General oilfield driver improvement

    International Nuclear Information System (INIS)

    Johnson, G.

    1997-01-01

    The general oilfield driver improvement (GODI) course was discussed. The course is offered to truckers in the oil and gas industry to help reduce accidents and injuries. Oilfield trucking is one of the most accident and injury prone sectors in the Alberta economy. This paper presented Heck's Trucking company's experience in sending its employees on the course. Drivers were taught (1) the National safety code requirements, (2) Commercial Vehicle Safety Alliance requirements, (3) occupational health and safety concerns, (4) vehicle dimension and GVW restrictions, (5) hours of service regulations, (6) log book and pre-trip inspection requirements, (7) workplace hazardous material information, and (8) transportation of dangerous goods. Overall, the course was judged to provide excellent training before sending drivers into the field. The employee, the customer, and the company, all stand to benefit from having rigorous and uniform standards for all drivers in the oil and gas industry

  2. Internet driver education study.

    Science.gov (United States)

    2010-05-01

    Incorporating technology through online courses, including drivers education (DE), is the wave of the future for : learning. While many states allow online DE as an accepted method of learning, Wisconsin currently only allows it on a : limited bas...

  3. VD-411 branch driver

    International Nuclear Information System (INIS)

    Gorbunov, N.V.; Karev, A.G.; Mal'tsev, Eh.I.; Morozov, B.A.

    1985-01-01

    The VD-411 branch driver for CAMAC moduli control by the SM-4 computer is described. The driver realizes data exchange with moduli disposed in 28 crates grouped in 4 branches. Data exchange can be carried out either in the program regime or in the regime of direct access to the memory. Fulfilment of 11 block regimes and one program regime is provided for. A possibility of individual programming of exchange methods in block regimes is left for users for organisation of quicker and most flexible data removal from the CAMAC moduli. In the regime of direct access the driver provides data transmission at the size up to 64 Kwords placing it in the computer memory of 2 M byte. High rate of data transmission and the developed system of interruptions ensure efficient utilization of the VD-411 branch driver at data removal from facilities in high energy physics experiments

  4. OLDER DRIVERS AND ADAS

    Directory of Open Access Journals (Sweden)

    Ragnhild J. DAVIDSE

    2006-01-01

    Next, based on the available literature, relevant ADAS are discussed in terms of their availability, their effects on safety and the willingness of older drivers to use and buy them. One of the conclusions is that only very few of the types of support that are thought to be most beneficial to the safety of older drivers are provided by the ADAS that are currently available.

  5. Analysis of MreB interactors in Chlamydia reveals a RodZ homolog but fails to detect an interaction with MraY.

    Science.gov (United States)

    Ouellette, Scot P; Rueden, Kelsey J; Gauliard, Emilie; Persons, Logan; de Boer, Piet A; Ladant, Daniel

    2014-01-01

    Chlamydia is an obligate intracellular bacterial pathogen that has significantly reduced its genome in adapting to the intracellular environment. One class of genes for which the bacterium has few annotated examples is cell division, and Chlamydia lacks FtsZ, a central coordinator of the division apparatus. We have previously implicated MreB as a potential substitute for FtsZ in Chlamydia (Ouellette et al., 2012). Thus, to identify new chlamydial cell division components, we searched for proteins that interacted with MreB. We performed a small-scale screen using a Gateway® compatible version of the Bacterial Adenylate Cyclase Two Hybrid (BACTH) system, BACTHGW, to detect proteins interacting with chlamydial MreB and identified a RodZ (YfgA) homolog. The chlamydial RodZ aligns well with the cytoplasmic domain of E. coli RodZ but lacks the periplasmic domain that is dispensable for rod cell shape maintenance in E. coli. The expression pattern of yfgA/rodZ was similar to that of mreB and ftsI, suggesting that these genes may operate in a common functional pathway. The chlamydial RodZ correctly localized to the membrane of E. coli but was unable to complement an E. coli rodZ mutant strain, likely because of the inability of chlamydial RodZ to interact with the native E. coli MreB. Finally, we also tested whether chlamydial MreB could interact with MraY, as suggested by Gaballah et al. (2011). However, we did not detect an interaction between these proteins even when using an implementation of the BACTH system to allow native orientation of the N- and C-termini of MraY in the periplasm. Thus, further work will be needed to establish this proposed interaction. In sum, we have added to the repertoire of potential cell division proteins of Chlamydia.

  6. Analysis of MreB interactors in Chlamydia reveals a RodZ homolog but fails to detect an interaction with MraY

    Directory of Open Access Journals (Sweden)

    Scot P Ouellette

    2014-06-01

    Full Text Available Chlamydia is an obligate intracellular bacterial pathogen that has significantly reduced its genome in adapting to the intracellular environment. One class of genes for which the bacterium has few annotated examples is cell division, and Chlamydia lacks FtsZ, a central coordinator of the division apparatus. We have previously implicated MreB as a potential substitute for FtsZ in Chlamydia (Ouellette et al., 2012. Thus, to identify new chlamydial cell division components, we searched for proteins that interacted with MreB. We performed a small-scale screen using a Gateway® compatible version of the Bacterial Adenylate Cyclase Two Hybrid (BACTH system, BACTHGW, to detect proteins interacting with chlamydial MreB and identified a RodZ (YfgA homolog. The chlamydial RodZ aligns well with the cytoplasmic domain of E. coli RodZ but lacks the periplasmic domain that is dispensable for rod cell shape maintenance in E. coli. The expression pattern of yfgA/rodZ was similar to that of mreB and ftsI, suggesting that these genes may operate in a common functional pathway. The chlamydial RodZ correctly localized to the membrane of E. coli but was unable to complement an E. coli rodZ mutant strain, likely because of the inability of chlamydial RodZ to interact with the native E. coli MreB. Finally, we also tested whether chlamydial MreB could interact with MraY, as suggested by Gaballah et al. (2011. However, we did not detect an interaction between these proteins even when using an implementation of the BACTH system to allow native orientation of the N- and C-termini of MraY in the periplasm. Thus, further work will be needed to establish this proposed interaction. In sum, we have added to the repertoire of potential cell division proteins of Chlamydia.

  7. Acoustic Levitation With One Driver

    Science.gov (United States)

    Wang, T. G.; Rudnick, I.; Elleman, D. D.; Stoneburner, J. D.

    1985-01-01

    Report discusses acoustic levitation in rectangular chamber using one driver mounted at corner. Placement of driver at corner enables it to couple effectively to acoustic modes along all three axes. Use of single driver reduces cost, complexity and weight of levitation system below those of three driver system.

  8. Characteristics of Chinese Driver Behavior

    NARCIS (Netherlands)

    Li, J.

    2014-01-01

    The high growth rate of vehicle ownership and many novel drivers in China determine the special features of Chinese driver behavior. This thesis introduces a comparative study on driver behavior by the analysis of saturation flow at urban intersections, Driver Behavior Questionnaire surveys, focus

  9. Analiza protokola kvaliteta usluga telekomunikacionih mreža / Analysis of quality of service protocols in telecommunication networks

    Directory of Open Access Journals (Sweden)

    Milojko Jevtović

    2003-05-01

    Full Text Available Protokoli kvaliteta usluga (Quality of Service - QoS sadašnjih i budućih telekomunikacionih mreža razvijeni su, pored ostalog, sa ciljem da podrže različite klase usluga (Class of Service - CoS komunikaciju u realnom vremenu, kao i prenos multimedijalnih poruka preko paketskih IP (Internet Protocol mreža. U raduje dat pregled karakteristika tih protokola i ocena njihovih konkretnih mogućnosti u obezbeđenju kvaliteta usluga unutar sistema ('s vrha do dna', tj. vertikalno u OSI arhitekturi kao i 'horizontalno' odnosno s kraja na kraj veze, tj. između izvora i odredišta. / Today's and future telecommunication networks must enable transmission throughout heterogeneous environment, using different Quality of Service protocols, Quality of Service protocols use a variety of complementary mechanisms to enable deterministic end-to-end different data delivery. The analysis of these protocols and their efficiency in providing QoS and CoS has been given in this paper.

  10. Intact Mre11/Rad50/Nbs1 Complex Predicts Good Response to Radiotherapy in Early Breast Cancer

    International Nuclear Information System (INIS)

    Soederlund, Karin; Stal, Olle; Skoog, Lambert; Rutqvist, Lars Erik; Nordenskjoeld, Bo; Askmalm, Marie Stenmark

    2007-01-01

    Purpose: To investigate the expression and predictive role of the Mre11/Rad50/Nbs1 (MRN) complex and the ataxia-telangiectasia mutated protein (ATM) for the outcome of radiotherapy in breast cancer patients. Methods and Materials: The protein expression of ATM and the DNA repair proteins in the MRN complex were investigated using immunohistochemistry in tumors from 224 women with early breast cancer, who were randomized to receive postoperative radiotherapy or adjuvant chemotherapy. Results: Compared with normal breast tissue, the staining intensity of Mre11, Rad50, Nbs1, and ATM was reduced in a majority of the tumors. Weak expression of the MRN complex was correlated with high histologic grade and estrogen receptor negativity (p = 0.01 and p 0.0001, respectively). Radiotherapy significantly reduced the risk of local recurrence as compared with chemotherapy (p = 0.04). The greatest benefit of radiotherapy was seen in patients with moderate/strong expression of the MRN complex (relative risk = 0.27, 95% confidence interval = 0.098-0.72, p 0.009), whereas patients with negative/weak MRN expression had no benefit of radiotherapy compared with adjuvant chemotherapy. These results suggest that an intact MRN complex is important for the tumor cell eradicating effect of radiotherapy. Conclusions: Reduced expression of the MRN complex predicts a poor effect of radiotherapy in patients with early breast cancer

  11. MRE11-Deficiency Associated with Improved Long-Term Disease Free Survival and Overall Survival in a Subset of Stage III Colon Cancer Patients in Randomized CALGB 89803 Trial

    Science.gov (United States)

    Pavelitz, Thomas; Renfro, Lindsay; Foster, Nathan R.; Caracol, Amber; Welsch, Piri; Lao, Victoria Valinluck; Grady, William B.; Niedzwiecki, Donna; Saltz, Leonard B.; Bertagnolli, Monica M.; Goldberg, Richard M.; Rabinovitch, Peter S.; Emond, Mary; Monnat, Raymond J.; Maizels, Nancy

    2014-01-01

    Purpose Colon cancers deficient in mismatch repair (MMR) may exhibit diminished expression of the DNA repair gene, MRE11, as a consequence of contraction of a T11 mononucleotide tract. This study investigated MRE11 status and its association with prognosis, survival and drug response in patients with stage III colon cancer. Patients and Methods Cancer and Leukemia Group B 89803 (Alliance) randomly assigned 1,264 patients with stage III colon cancer to postoperative weekly adjuvant bolus 5-fluorouracil/leucovorin (FU/LV) or irinotecan+FU/LV (IFL), with 8 year follow-up. Tumors from these patients were analyzed to determine stability of a T11 tract in the MRE11 gene. The primary endpoint was overall survival (OS), and a secondary endpoint was disease-free survival (DFS). Non-proportional hazards were addressed using time-dependent covariates in Cox analyses. Results Of 625 tumor cases examined, 70 (11.2%) exhibited contraction at the T11 tract in one or both MRE11 alleles and were thus predicted to be deficient in MRE11 (dMRE11). In pooled treatment analyses, dMRE11 patients showed initially reduced DFS and OS but improved long-term DFS and OS compared with patients with an intact MRE11 T11 tract. In the subgroup of dMRE11 patients treated with IFL, an unexplained early increase in mortality but better long-term DFS than IFL-treated pMRE11 patients was observed. Conclusions Analysis of this relatively small number of patients and events showed that the dMRE11 marker predicts better prognosis independent of treatment in the long-term. In subgroup analyses, dMRE11 patients treated with irinotecan exhibited unexplained short-term mortality. MRE11 status is readily assayed and may therefore prove to be a useful prognostic marker, provided that the results reported here for a relatively small number of patients can be generalized in independent analyses of larger numbers of samples. Trial Registration ClinicalTrials.gov NCT00003835 PMID:25310185

  12. MRE11-deficiency associated with improved long-term disease free survival and overall survival in a subset of stage III colon cancer patients in randomized CALGB 89803 trial.

    Directory of Open Access Journals (Sweden)

    Thomas Pavelitz

    Full Text Available Colon cancers deficient in mismatch repair (MMR may exhibit diminished expression of the DNA repair gene, MRE11, as a consequence of contraction of a T11 mononucleotide tract. This study investigated MRE11 status and its association with prognosis, survival and drug response in patients with stage III colon cancer.Cancer and Leukemia Group B 89803 (Alliance randomly assigned 1,264 patients with stage III colon cancer to postoperative weekly adjuvant bolus 5-fluorouracil/leucovorin (FU/LV or irinotecan+FU/LV (IFL, with 8 year follow-up. Tumors from these patients were analyzed to determine stability of a T11 tract in the MRE11 gene. The primary endpoint was overall survival (OS, and a secondary endpoint was disease-free survival (DFS. Non-proportional hazards were addressed using time-dependent covariates in Cox analyses.Of 625 tumor cases examined, 70 (11.2% exhibited contraction at the T11 tract in one or both MRE11 alleles and were thus predicted to be deficient in MRE11 (dMRE11. In pooled treatment analyses, dMRE11 patients showed initially reduced DFS and OS but improved long-term DFS and OS compared with patients with an intact MRE11 T11 tract. In the subgroup of dMRE11 patients treated with IFL, an unexplained early increase in mortality but better long-term DFS than IFL-treated pMRE11 patients was observed.Analysis of this relatively small number of patients and events showed that the dMRE11 marker predicts better prognosis independent of treatment in the long-term. In subgroup analyses, dMRE11 patients treated with irinotecan exhibited unexplained short-term mortality. MRE11 status is readily assayed and may therefore prove to be a useful prognostic marker, provided that the results reported here for a relatively small number of patients can be generalized in independent analyses of larger numbers of samples.ClinicalTrials.gov NCT00003835.

  13. Effects of Initial Drivers and Land Use on WRF Modeling for Near-Surface Fields and Atmospheric Boundary Layer over the Northeastern Tibetan Plateau

    Directory of Open Access Journals (Sweden)

    Junhua Yang

    2016-01-01

    Full Text Available To improve the simulation performance of mesoscale models in the northeastern Tibetan Plateau, two reanalysis initial datasets (NCEP FNL and ERA-Interim and two MODIS (Moderate-Resolution Imaging Spectroradiometer land-use datasets (from 2001 and 2010 are used in WRF (Weather Research and Forecasting modeling. The model can reproduce the variations of 2 m temperature (T2 and 2 m relative humidity (RH2, but T2 is overestimated and RH2 is underestimated in the control experiment. After using the new initial drive and land use data, the simulation precision in T2 is improved by the correction of overestimated net energy flux at surface and the RH2 is improved due to the lower T2 and larger soil moisture. Due to systematic bias in WRF modeling for wind speed, we design another experiment that includes the Jimenez subgrid-scale orography scheme, which reduces the frequency of low wind speed and increases the frequency of high wind speed and that is more consistent with the observation. Meanwhile, the new drive and land-use data lead to lower boundary layer height and influence the potential temperature and wind speed in both the lower atmosphere and the upper layer, while the impact on water vapor mixing ratio is primarily concentrated in the lower atmosphere.

  14. Exact mapping of the dx2-y2 Cooper-pair wavefunction onto the spin fluctuations in cuprates: the Fermi surface as a driver for 'high Tc' superconductivity

    International Nuclear Information System (INIS)

    McDonald, Ross D; Harrison, Neil; Singleton, John

    2009-01-01

    We propose that the extraordinarily high superconducting transition temperatures in the cuprates are driven by an exact mapping of the d x 2 -y 2 Cooper-pair wavefunction onto the incommensurate spin fluctuations observed in neutron-scattering experiments. This is manifested in the direct correspondence between the inverse of the incommensurability factor δ seen in inelastic neutron-scattering experiments and the measured superconducting coherence length ξ 0 . Strikingly, the relationship between ξ 0 and δ is valid for both La 2-x Sr x CuO 4 and YBa 2 Cu 3 O 7-x , suggesting a common mechanism for superconductivity across the entire hole-doped cuprate family. Using data from recent quantum-oscillation experiments in the cuprates, we propose that the fluctuations responsible for superconductivity are driven by a Fermi-surface instability. On the basis of these findings, one can specify the optimal characteristics of a solid that will exhibit 'high T c ' superconductivity. (fast track communication)

  15. Anti-Pseudomonas aeruginosa compound, 1,2,3,4-tetrahydro-1,3,5-triazine derivative, exerts its action by primarily targeting MreB.

    Science.gov (United States)

    Yamachika, Shinichiro; Sugihara, Chika; Tsuji, Hayato; Muramatsu, Yasunori; Kamai, Yasuki; Yamashita, Makoto

    2012-01-01

    In order to find new anti-Pseudomonas agents, we carried out whole-cell based P. aeruginosa growth assay, and identified 1,2,3,4-tetrahydro-1,3,5-triazine (Compound A). This compound showed anti-Pseudomonas activity against wild as well as pumpless strain equally at a same concentration. Also, this compound was structurally very similar to A22, which is known to inhibit the bacterial actin-like protein MreB. By the analysis of resistant strains, the primary target of this compound in P. aeruginosa was definitely confirmed to be MreB. In addition, these compounds showed a bacteriostatic effect, and induced the morphology changes in P. aeruginosa from rod shape to sphere shape, which leads to be clinically favorable in terms of susceptibility to phagocytosis and release of endotoxin. These results display that Compound A is a very attractive compound which shows anti-P. aeruginosa activity based on inhibition of MreB without being affected by efflux pumps, and could provide a new step toward development of new promising anti-Pseudomonas agents, MreB inhibitors.

  16. Direct interaction of FtsZ and MreB is required for septum synthesis and cell division in Escherichia coli.

    Science.gov (United States)

    Fenton, Andrew K; Gerdes, Kenn

    2013-07-03

    How bacteria coordinate cell growth with division is not well understood. Bacterial cell elongation is controlled by actin-MreB while cell division is governed by tubulin-FtsZ. A ring-like structure containing FtsZ (the Z ring) at mid-cell attracts other cell division proteins to form the divisome, an essential protein assembly required for septum synthesis and cell separation. The Z ring exists at mid-cell during a major part of the cell cycle without contracting. Here, we show that MreB and FtsZ of Escherichia coli interact directly and that this interaction is required for Z ring contraction. We further show that the MreB-FtsZ interaction is required for transfer of cell-wall biosynthetic enzymes from the lateral to the mature divisome, allowing cells to synthesise the septum. Our observations show that bacterial cell division is coupled to cell elongation via a direct and essential interaction between FtsZ and MreB.

  17. Biogeochemical and microbial variation across 5500 km of Antarctic surface sediment implicates organic matter as a driver of benthic community structure

    Directory of Open Access Journals (Sweden)

    Deric R Learman

    2016-03-01

    Full Text Available Western Antarctica, one of the fastest warming locations on Earth, is a unique environment that is underexplored with regards to biodiversity. Although pelagic microbial communities in the Southern Ocean and coastal Antarctic waters have been well studied, there are fewer investigations of benthic communities and most have a focused geographic range. We sampled surface sediment from 24 sites across a 5,500 km region of Western Antarctica (covering the Ross Sea to the Weddell Sea to examine relationships between microbial communities and sediment geochemistry. Sequencing of the 16S and 18S rRNA genes showed microbial communities in sediments from the Antarctic Peninsula (AP and Western Antarctica (WA, including the Ross, Amundsen, and Bellingshausen Seas, could be distinguished by correlations with organic matter concentrations and stable isotope fractionation (total organic carbon; TOC, nitrogen, and δ13C. Overall, samples from the AP were higher in nutrient content (TOC, nitrogen, and NH4+ and communities in these samples had higher relative abundances of operational taxonomic units (OTUs classified as the diatom, Chaetoceros, a marine cercozoan and four OTUs classified as Cytophaga or Flavobacteria. As these OTUs were strongly correlated with TOC, the data suggests the diatoms could be a source of organic matter and the Bacteroidetes and cercozoan are grazers that consume the organic matter. Additionally, samples from WA have lower nutrients and were dominated by Thaumarchaeota, which could be related to their known ability to thrive as lithotrophs. This study documents the largest analysis of benthic microbial communities to date in the Southern Ocean, representing almost half the continental shoreline of Antarctica, and documents trophic interactions and coupling of pelagic and benthic communities. Our results indicate potential modifications in carbon sequestration processes related to change in community composition, identifying a

  18. Schoolbus driver performance can be improved with driver training ...

    African Journals Online (AJOL)

    and compares the school transport driver performance with that of general motorists. Despite concerns that ... To compare Safe Travel to School Programme driver safety perfor- .... The SA government has recognised the challenges faced with.

  19. SCALE system driver

    International Nuclear Information System (INIS)

    Petrie, L.M.

    1984-01-01

    The SCALE driver was designed to allow implementation of a modular code system consisting of control modules, which determine the calculation path, and functional modules, which perform the basic calculations. The user can either select a control module and have that module determine the execution path, or the user can select functional modules directly by input

  20. Simulators in driver training.

    NARCIS (Netherlands)

    2009-01-01

    In 2010, about 150 driving simulators were being used for the basic driver training in the Netherlands. According to theories about how people learn, simulator training has both advantages and disadvantages. In order to be able to learn something from a simulator, its technical quality must be

  1. Space Age Driver Education

    Science.gov (United States)

    Gray, Walter W.

    1970-01-01

    Describes experimental Driver and Traffic Safety Education Center--a project involving a five-phase instructional program, a variety of teaching innovations, and a specially-constructed facility which includes a classroom building, multiple car driving range, simulators, communications equipment, and the most recent electronic teaching devices.…

  2. Beginning teenage drivers

    Science.gov (United States)

    2010-01-01

    Teen drivers have the highest crash risk of any age group. Per mile traveled, they have the highest involvement rates in all types of crashes, from those involving only property damage to those that are fatal. The problem is worst among 16 year-olds,...

  3. Genetic variants in ATM, H2AFX and MRE11 genes and susceptibility to breast cancer in the polish population.

    Science.gov (United States)

    Podralska, Marta; Ziółkowska-Suchanek, Iwona; Żurawek, Magdalena; Dzikiewicz-Krawczyk, Agnieszka; Słomski, Ryszard; Nowak, Jerzy; Stembalska, Agnieszka; Pesz, Karolina; Mosor, Maria

    2018-04-20

    DNA damage repair is a complex process, which can trigger the development of cancer if disturbed. In this study, we hypothesize a role of variants in the ATM, H2AFX and MRE11 genes in determining breast cancer (BC) susceptibility. We examined the whole sequence of the ATM kinase domain and estimated the frequency of founder mutations in the ATM gene (c.5932G > T, c.6095G > A, and c.7630-2A > C) and single nucleotide polymorphisms (SNPs) in H2AFX (rs643788, rs8551, rs7759, and rs2509049) and MRE11 (rs1061956 and rs2155209) among 315 breast cancer patients and 515 controls. The analysis was performed using high-resolution melting for new variants and the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method for recurrent ATM mutations. H2AFX and MRE11 polymorphisms were analyzed using TaqMan assays. The cumulative genetic risk scores (CGRS) were calculated using unweighted and weighted approaches. We identified four mutations (c.6067G > A, c.8314G > A, c.8187A > T, and c.6095G > A) in the ATM gene in three BC cases and two control subjects. We observed a statistically significant association of H2AFX variants with BC. Risk alleles (the G of rs7759 and the T of rs8551 and rs2509049) were observed more frequently in BC cases compared to the control group, with P values, odds ratios (OR) and 95% confidence intervals (CIs) of 0.0018, 1.47 (1.19 to 1.82); 0.018, 1.33 (1.09 to 1.64); and 0.024, 1.3 (1.06 to 1.59), respectively. Haplotype-based tests identified a significant association of the H2AFX CACT haplotype with BC (P ATM gene to the development of breast cancer needs further detailed study.

  4. Mre11 and Blm-Dependent Formation of ALT-Like Telomeres in Ku-Deficient Ustilago maydis.

    Directory of Open Access Journals (Sweden)

    Eun Young Yu

    2015-10-01

    Full Text Available A subset of human cancer cells uses a specialized, aberrant recombination pathway known as ALT to maintain telomeres, which in these cells are characterized by complex aberrations including length heterogeneity, high levels of unpaired C-strand, and accumulation of extra-chromosomal telomere repeats (ECTR. These phenotypes have not been recapitulated in any standard budding or fission yeast mutant. We found that eliminating Ku70 or Ku80 in the yeast-like fungus Ustilago maydis results initially in all the characteristic telomere aberrations of ALT cancer cells, including C-circles, a highly specific marker of ALT. Subsequently the ku mutants experience permanent G2 cell cycle arrest, accompanied by loss of telomere repeats from chromosome ends and even more drastic accumulation of very short ECTRs (vsECTRs. The deletion of atr1 or chk1 rescued the lethality of the ku mutant, and "trapped" the telomere aberrations in the early ALT-like stage. Telomere abnormalities are telomerase-independent, but dramatically suppressed by deletion of mre11 or blm, suggesting major roles for these factors in the induction of the ALT pathway. In contrast, removal of other DNA damage response and repair factors such as Rad51 has disparate effects on the ALT phenotypes, suggesting that these factors process ALT intermediates or products. Notably, the antagonism of Ku and Mre11 in the induction of ALT is reminiscent of their roles in DSB resection, in which Blm is also known to play a key role. We suggest that an aberrant resection reaction may constitute an early trigger for ALT telomeres, and that the outcomes of ALT are distinct from DSB because of the unique telomere nucleoprotein structure.

  5. Negativity Bias in Dangerous Drivers.

    Directory of Open Access Journals (Sweden)

    Jing Chai

    Full Text Available The behavioral and cognitive characteristics of dangerous drivers differ significantly from those of safe drivers. However, differences in emotional information processing have seldom been investigated. Previous studies have revealed that drivers with higher anger/anxiety trait scores are more likely to be involved in crashes and that individuals with higher anger traits exhibit stronger negativity biases when processing emotions compared with control groups. However, researchers have not explored the relationship between emotional information processing and driving behavior. In this study, we examined the emotional information processing differences between dangerous drivers and safe drivers. Thirty-eight non-professional drivers were divided into two groups according to the penalty points that they had accrued for traffic violations: 15 drivers with 6 or more points were included in the dangerous driver group, and 23 drivers with 3 or fewer points were included in the safe driver group. The emotional Stroop task was used to measure negativity biases, and both behavioral and electroencephalograph data were recorded. The behavioral results revealed stronger negativity biases in the dangerous drivers than in the safe drivers. The bias score was correlated with self-reported dangerous driving behavior. Drivers with strong negativity biases reported having been involved in mores crashes compared with the less-biased drivers. The event-related potentials (ERPs revealed that the dangerous drivers exhibited reduced P3 components when responding to negative stimuli, suggesting decreased inhibitory control of information that is task-irrelevant but emotionally salient. The influence of negativity bias provides one possible explanation of the effects of individual differences on dangerous driving behavior and traffic crashes.

  6. Automobile Driver Fingerprinting

    Directory of Open Access Journals (Sweden)

    Enev Miro

    2016-01-01

    Full Text Available Today’s automobiles leverage powerful sensors and embedded computers to optimize efficiency, safety, and driver engagement. However the complexity of possible inferences using in-car sensor data is not well understood. While we do not know of attempts by automotive manufacturers or makers of after-market components (like insurance dongles to violate privacy, a key question we ask is: could they (or their collection and later accidental leaks of data violate a driver’s privacy? In the present study, we experimentally investigate the potential to identify individuals using sensor data snippets of their natural driving behavior. More specifically we record the in-vehicle sensor data on the controllerarea- network (CAN of a typical modern vehicle (popular 2009 sedan as each of 15 participants (a performed a series of maneuvers in an isolated parking lot, and (b drove the vehicle in traffic along a defined ~ 50 mile loop through the Seattle metropolitan area. We then split the data into training and testing sets, train an ensemble of classifiers, and evaluate identification accuracy of test data queries by looking at the highest voted candidate when considering all possible one-vs-one comparisons. Our results indicate that, at least among small sets, drivers are indeed distinguishable using only incar sensors. In particular, we find that it is possible to differentiate our 15 drivers with 100% accuracy when training with all of the available sensors using 90% of driving data from each person. Furthermore, it is possible to reach high identification rates using less than 8 minutes of training data. When more training data is available it is possible to reach very high identification using only a single sensor (e.g., the brake pedal. As an extension, we also demonstrate the feasibility of performing driver identification across multiple days of data collection

  7. Driver feedback mobile APP

    Energy Technology Data Exchange (ETDEWEB)

    Soriguera Marti, F.; Miralles Miquel, E.

    2016-07-01

    This paper faces the human factor in driving and its consequences for road safety. It presents the concepts behind the development of a smartphone app capable of evaluating drivers’ performance. The app provides feedback to the driver in terms of a grade (between 0 and 10) depending on the aggressiveness and risks taken while driving. These are computed from the cumulative probability distribution function of the jerks (i.e. the time derivative of acceleration), which are measured using the smartphones’ accelerometer. Different driving contexts (e.g. urban, freeway, congestion, etc.) are identified applying cluster analysis to the measurements, and treated independently. Using regression analysis, the aggressiveness indicator is related to the drivers' safety records and to the probability of having an accident, through the standard DBQ - Driving Behavior Questionnaire. Results from a very limited pilot test show a strong correlation between the 99th percentile of the jerk measurements and the DBQ results. A linear model is fitted. This allows quantifying the safe driving behavior only from smartphone measurements. Finally, this indicator is translated into a normalized grade and feedback to the driver. This feedback will challenge the driver to train and to improve his performance. The phone will be blocked while driving and will incorporate mechanisms to prevent bad practices, like competition in aggressive driving. The app is intended to contribute to the improvement of road safety, one of the major public health problems, by tackling the human factor which is the trigger of the vast majority of traffic accidents. Making explicit and quantifying risky behaviors is the first step towards a safer driving. (Author)

  8. Education and driver-training

    Directory of Open Access Journals (Sweden)

    Andrej Justinek

    1999-12-01

    Full Text Available The characteristics of the driver are manifested in his/her behaviour. For safe driving one must have a driver's knowledge. The contents of educational material are determined by law, and are both theoretical and practical, yet frequently they do not suffice to meet the requirements of safe driving. In this paper, the author suggests that, in the training of drivers, more educational elements should be included, such a would have  an effective influence on the driver's moti ves and attitudes. The driver's motives - which may result in incorrect driving­ are diverse: most often, the default is overspeeding, even though the drivers always over-estimate the potential time gain. In fact, over-fast driving is a way of satisfying other, different needs; and, above all, it is a form of compensation for unsettled life problems, and at the same time an indication of the driver's personal inability to cope with stress.

  9. Are professional drivers less sleepy than non-professional drivers?

    Science.gov (United States)

    Anund, Anna; Ahlström, Christer; Fors, Carina; Åkerstedt, Torbjörn

    2018-01-01

    Objective It is generally believed that professional drivers can manage quite severe fatigue before routine driving performance is affected. In addition, there are results indicating that professional drivers can adapt to prolonged night shifts and may be able to learn to drive without decreased performance under high levels of sleepiness. However, very little research has been conducted to compare professionals and non-professionals when controlling for time driven and time of day. Method The aim of this study was to use a driving simulator to investigate whether professional drivers are more resistant to sleep deprivation than non-professional drivers. Differences in the development of sleepiness (self-reported, physiological and behavioral) during driving was investigated in 11 young professional and 15 non-professional drivers. Results Professional drivers self-reported significantly lower sleepiness while driving a simulator than non-professional drivers. In contradiction, they showed longer blink durations and more line crossings, both of which are indicators of sleepiness. They also drove faster. The reason for the discrepancy in the relation between the different sleepiness indicators for the two groups could be due to more experience to sleepiness among the professional drivers or possibly to the faster speed, which might unconsciously have been used by the professionals to try to counteract sleepiness. Conclusion Professional drivers self-reported significantly lower sleepiness while driving a simulator than non-professional drivers. However, they showed longer blink durations and more line crossings, both of which are indicators of sleepiness, and they drove faster.

  10. An examination of the environmental, driver and vehicle factors associated with the serious and fatal crashes of older rural drivers.

    Science.gov (United States)

    Thompson, J P; Baldock, M R J; Mathias, J L; Wundersitz, L N

    2013-01-01

    Motor vehicle crashes involving rural drivers aged 75 years and over are more than twice as likely to result in a serious or fatal injury as those involving their urban counterparts. The current study examined some of the reasons for this using a database of police-reported crashes (2004-2008) to identify the environmental (lighting, road and weather conditions, road layout, road surface, speed limit), driver (driver error, crash type), and vehicle (vehicle age) factors that are associated with the crashes of older rural drivers. It also determined whether these same factors are associated with an increased likelihood of serious or fatal injury in younger drivers for whom frailty does not contribute to the resulting injury severity. A number of environmental (i.e., undivided, unsealed, curved and inclined roads, and areas with a speed limit of 100km/h or greater) and driver (i.e., collision with a fixed object and rolling over) factors were more frequent in the crashes of older rural drivers and additionally associated with increased injury severity in younger drivers. Moreover, when these environmental factors were entered into a logistic regression model to predict whether older drivers who were involved in crashes did or did not sustain a serious or fatal injury, it was found that each factor independently increased the likelihood of a serious or fatal injury. Changes, such as the provision of divided and sealed roads, greater protection from fixed roadside objects, and reduced speed limits, appear to be indicated in order to improve the safety of the rural driving environment for drivers of all ages. Additionally, older rural drivers should be encouraged to reduce their exposure to these risky circumstances. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Heavy ion driver technology

    International Nuclear Information System (INIS)

    Keefe, D.

    1988-09-01

    Major differences between fusion drivers and traditional accelerators include the following. The final beam current needed (/approximately/20 kA in a short pulse) is very much larger for a driver; such beams are dominated by repulsive space-charge effects since, even at 10 GeV, the ions are non-relativistic (v/c = 0.3). Also, the optical quality of the beams (called emittance by accelerator people) must be extremely good to ensure a suitably small focal spot at the pellet. Two schemes, one with a rf linac and storage rings, the other with a single-pass current-amplifying induction linac, are under study, the latter exclusively in the US. The induction linac approach lends itself to an examination in a sequence of scaled-down laboratory experiments since the most difficulties are expected to occur at the low energy end. Experiments and simulation have centered on a study of the transverse and longitudinal control of space-charge-dominated beams which are best described in terms of a non-neutral plasma rather than the traditional single-particle dynamics picture. An understanding of the high-current instability limits is required for arriving at a safe driver design. The final on-target beam current is so high that it must be carried in 16 separate focusing channels leading into the combustion chamber. While the energy deposition of the ions is expected to be entirely classical, there is a wealth of plasma physics phenomena to be explored (by theory and simulation) in the final propagation of these beams through the low-density gas in the chamber and in the environment of the hot target; it is important that none of these could result in a significant portion of the beam missing the focal spot. 13 refs., 9 figs., 1 tab

  12. Drivers for Welfare Innovation

    DEFF Research Database (Denmark)

    Wegener, Charlotte

    2015-01-01

    Innovation has become a key goal towards which teaching and workplace learning needs to be directed. Now perceived as germane and even necessary in almost all kinds of welfare work, the innovation potential in everyday practices and ways of allowing for employer creativity have become a highly...... on the empirical material, the paper proposes a ‘driver’ model for context sensitive research of innovation in welfare workplaces. The model involves three elements which can be regarded as drivers for innovation: i) craft (i.e. professional skills and knowledge), ii) levers (i.e. experiments and adjustment...

  13. PrkC-mediated phosphorylation of overexpressed YvcK protein regulates PBP1 protein localization in Bacillus subtilis mreB mutant cells.

    Science.gov (United States)

    Foulquier, Elodie; Pompeo, Frédérique; Freton, Céline; Cordier, Baptiste; Grangeasse, Christophe; Galinier, Anne

    2014-08-22

    The YvcK protein has been shown to be necessary for growth under gluconeogenic conditions in Bacillus subtilis. Amazingly, its overproduction rescues growth and morphology defects of the actin-like protein MreB deletion mutant by restoration of PBP1 localization. In this work, we observed that YvcK was phosphorylated at Thr-304 by the protein kinase PrkC and that phosphorylated YvcK was dephosphorylated by the cognate phosphatase PrpC. We show that neither substitution of this threonine with a constitutively phosphorylated mimicking glutamic acid residue or a phosphorylation-dead mimicking alanine residue nor deletion of prkC or prpC altered the ability of B. subtilis to grow under gluconeogenic conditions. However, we observed that a prpC mutant and a yvcK mutant were more sensitive to bacitracin compared with the WT strain. In addition, the bacitracin sensitivity of strains in which YvcK Thr-304 was replaced with either an alanine or a glutamic acid residue was also affected. We also analyzed rescue of the mreB mutant strain by overproduction of YvcK in which the phosphorylation site was substituted. We show that YvcK T304A overproduction did not rescue the mreB mutant aberrant morphology due to PBP1 mislocalization. The same observation was made in an mreB prkC double mutant overproducing YvcK. Altogether, these data show that YvcK may have two distinct functions: 1) in carbon source utilization independent of its phosphorylation level and 2) in cell wall biosynthesis and morphogenesis through its phosphorylation state. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

  14. Temporal Regulation of the Bacillus subtilis Acetylome and Evidence for a Role of MreB Acetylation in Cell Wall Growth.

    Science.gov (United States)

    Carabetta, Valerie J; Greco, Todd M; Tanner, Andrew W; Cristea, Ileana M; Dubnau, David

    2016-05-01

    N ε -Lysine acetylation has been recognized as a ubiquitous regulatory posttranslational modification that influences a variety of important biological processes in eukaryotic cells. Recently, it has been realized that acetylation is also prevalent in bacteria. Bacteria contain hundreds of acetylated proteins, with functions affecting diverse cellular pathways. Still, little is known about the regulation or biological relevance of nearly all of these modifications. Here we characterize the cellular growth-associated regulation of the Bacillus subtilis acetylome. Using acetylation enrichment and quantitative mass spectrometry, we investigate the logarithmic and stationary growth phases, identifying over 2,300 unique acetylation sites on proteins that function in essential cellular pathways. We determine an acetylation motif, EK(ac)(D/Y/E), which resembles the eukaryotic mitochondrial acetylation signature, and a distinct stationary-phase-enriched motif. By comparing the changes in acetylation with protein abundances, we discover a subset of critical acetylation events that are temporally regulated during cell growth. We functionally characterize the stationary-phase-enriched acetylation on the essential shape-determining protein MreB. Using bioinformatics, mutational analysis, and fluorescence microscopy, we define a potential role for the temporal acetylation of MreB in restricting cell wall growth and cell diameter. The past decade highlighted N ε -lysine acetylation as a prevalent posttranslational modification in bacteria. However, knowledge regarding the physiological importance and temporal regulation of acetylation has remained limited. To uncover potential regulatory roles for acetylation, we analyzed how acetylation patterns and abundances change between growth phases in B. subtilis . To demonstrate that the identification of cell growth-dependent modifications can point to critical regulatory acetylation events, we further characterized MreB, the cell

  15. Photodetachment of free hexahalogenometallate doubly charged anions in the gas phase: [ML6]2-, (M=Re, Os, Ir, Pt; L=Cl and Br)

    International Nuclear Information System (INIS)

    Wang, X.; Wang, L.

    1999-01-01

    We report the first observation and photodetachment photoelectron spectroscopic study of a series of hexahalogenometallates dianions MCl 6 2- (M=Re, Os, Ir, and Pt) and MBr 6 2- (M=Re, Ir, and Pt) in the gas phase. All of these species were found to be stable as free gaseous doubly charged anions. Photoelectron spectra of all the dianions were obtained at several detachment photon energies. The photon-energy-dependent spectra clearly revealed the dianion nature of these species and allowed the repulsive Coulomb barriers to be estimated. The binding energies of the second excess electron in MCl 6 2- (M=Re, Os, Ir, Pt) were determined to be 0.46 (5), 0.46 (5), 0.82 (5), and 1.58 (5) eV, respectively, and those in MBr 6 2- (M=Re, Ir, Pt) to be 0.76 (6), 0.96 (6), and 1.52 (6) eV, respectively. A wealth of electronic structure information about these metal complexes were obtained and low-lying and highly-excited electronic states of the corresponding singly charged anions were observed. Detachment from metal d orbitals or ligand orbitals were observed and could be clearly distinguished; detachments from the metal d-orbitals all occur at low binding energies whereas those from the ligand-dominated orbitals all take place at rather high binding energies. We also found a remarkable correlation between electron affinities measured in vacuo and the redox potentials obtained in the solution phase of these species. copyright 1999 American Institute of Physics

  16. Driver Distraction in Public Transport

    OpenAIRE

    YOUNG, K; SALMON, P; REGAN MICHAEL, M

    2007-01-01

    There is converging evidence that driver distraction is a contributing factor in car crashes, in Australia and overseas. Surprisingly, no known previous research has attempted to identify and assess the potentially distracting activities undertaken by the drivers of public passenger vehicles. This paper describes research undertaken on this issue. The research was partitioned into three phases: an analysis of the functions and tasks currently undertaken by public passenger vehicle drivers; th...

  17. YeeV is an Escherichia coli toxin that inhibits cell division by targeting the cytoskeleton proteins, FtsZ and MreB.

    Science.gov (United States)

    Tan, Qian; Awano, Naoki; Inouye, Masayori

    2011-01-01

    Toxin-antitoxin (TA) systems of free-living bacteria have recently demonstrated that these toxins inhibit cell growth by targeting essential functions of cellular metabolism. Here we show that YeeV toxin inhibits cell division, leads to a change in morphology and lysis of Escherichia coli cells. YeeV interacts with two essential cytoskeleton proteins, FtsZ and MreB. Purified YeeV inhibits both the GTPase activity and the GTP-dependent polymerization of FtsZ. YeeV also inhibits ATP-dependent polymerization of MreB. Truncated C-terminal deletions of YeeV result in elongation of cells, and a deletion of the first 15 amino acids from the N-terminus of YeeV caused lemon-shaped cell formation. The YeeV toxin is distinct from other well-studied toxins: it directs the binding of two cytoskeletal proteins and inhibits FtsZ and MreB simultaneously. © 2010 Blackwell Publishing Ltd.

  18. Molecular breeding of the Mureka-non-forming sake koji mold from Aspergillus oryzae by the disruption of the mreA gene.

    Science.gov (United States)

    Kubodera, Takafumi; Yamashita, Nobuo; Nishimura, Akira

    2003-01-01

    Mureka-non-forming sake koji molds were constructed from an Aspergillus oryzae industrial strain by the disruption of the mreA gene using a host-vector system with the ptrA gene as a dominant selectable marker. All of the mreA gene disruptants obtained retained the advantages of the host strain in terms of the brewing characteristics, while their isoamyl alcohol oxidase (IAAOD) activities were significantly lower than that of the host strain. Sake brewing was successfully carried out using the koji prepared with the disruptants, followed by storage of the resultant non-pasteurized sake (nama-shu). The isovaleraldehyde (i-Val) concentration in the sake brewed the host strain increased rapidly and reached the threshold values for mureka, 1.8 ppm and 2.6 ppm after storage at 20 degrees C for 42 d and 63 d, respectively, while those of the disruptants were less than 0.5 ppm even after storage at 20 degrees C or 30 degrees C for 63 d. In the sensory evaluation of the sake stored at 20 degrees C or 30 degrees C for 63 d, all members of the panel recognized the strong mureka flavor of the sake brewed with the host strain, while they did not detect this flavor in the sake brewed with the disruptants. Thus, we concluded that the mreA gene disruptants can be used for the production of sake in which mureka is not formed.

  19. Changes in nucleoid morphology and origin localization upon inhibition or alteration of the actin homolog, MreB, of Vibrio cholerae.

    Science.gov (United States)

    Srivastava, Preeti; Demarre, Gäelle; Karpova, Tatiana S; McNally, James; Chattoraj, Dhruba K

    2007-10-01

    MreB is an actin homolog required for the morphogenesis of most rod-shaped bacteria and for other functions, including chromosome segregation. In Caulobacter crescentus and Escherichia coli, the protein seems to play a role in the segregation of sister origins, but its role in Bacillus subtilis chromosome segregation is less clear. To help clarify its role in segregation, we have here studied the protein in Vibrio cholerae, whose chromosome I segregates like the one in C. crescentus and whose chromosome II like the one in E. coli or B. subtilis. The properties of Vibrio MreB were similar to those of its homologs in other bacteria in that it formed dynamic helical filaments, was essential for viability, and was inhibited by the drug A22. Wild-type (WT) cells exposed to A22 became spherical and larger. The nucleoids enlarged correspondingly, and the origin positions for both the chromosomes no longer followed any fixed pattern. However, the sister origins separated, unlike the situation in other bacteria. In mutants isolated as A22 resistant, the nucleoids in some cases appeared compacted even when the cell shape was nearly normal. In these cells, the origins of chromosome I were at the distal edges of the nucleoid but not all the way to the poles where they normally reside. The sister origins of chromosome II also separated less. Thus, it appears that the inhibition or alteration of Vibrio MreB can affect both the nucleoid morphology and origin localization.

  20. Driver training in steps (DTS).

    NARCIS (Netherlands)

    2010-01-01

    For some years now, it has been possible in the Netherlands to follow a Driver Training in Steps (DTS) as well as the regular driver training. The DTS is a structured training method with clear training objectives which are categorized in four modules. Although the DTS is considerably better than

  1. Petrochemical industry drivers

    International Nuclear Information System (INIS)

    Sedriks, W.

    1995-01-01

    Extensive analyses of profit-ability and pricing over the years have shown that the trends seen in the petrochemical industry have two dominant drivers, namely, industry experience curves (reflecting continuous process improvement and cost savings) and profitability cycles. Any outlook for the future must examine both of these facets. The author's algorithm for price projections has two primary terms: a cost-related one and a supply/demand-related one. Both are strong functions of experience curves; the latter is also a prime function of cyclicality. At SRI International. To arrive at medium-term quantitative projections, SRI typically creates a consistent base-case scenario that more or less mirrors the past but also incorporates observed directional changes. In this article the author examines in detail how these scenarios are used for projection. He describes experience curves, ethylene/gross domestic product (GDP) penetration levels, industry structure, and cyclicality as they apply to ethylene prices

  2. Drivers of Collaborative Advantage

    DEFF Research Database (Denmark)

    Weihe, Gudrid

    processes and behavioural dimensions is practically non-existent. This article tries to remedy the current gap in the literature by reviewing research findings on interfirm collaboration (alliances). On that basis a conceptual framework for analyzing partnership processes is developed. Finally......, the antecedents of collaborative advantage are theoretically examined, and the organizational competences contributing to collaborative success are identified. The conclusion is that operational processes and social dynamics are vital drivers of collaborative advantage. Another significant conclusion...... is that public management research can benefit from drawing upon existing alliance research. Alliance scholars have during the past couple of decades accumulated an impressive amount of knowledge on different aspects of inter-firm cooperation, and therefore the learning potential for public management scholars...

  3. Alternate laser fusion drivers

    International Nuclear Information System (INIS)

    Pleasance, L.D.

    1979-11-01

    One objective of research on inertial confinement fusion is the development of a power generating system based on this concept. Realization of this goal will depend on the availability of a suitable laser or other system to drive the power plant. The primary laser systems used for laser fusion research, Nd 3+ : Glass and CO 2 , have characteristics which may preclude their use for this application. Glass lasers are presently perceived to be incapable of sufficiently high average power operation and the CO 2 laser may be limited by and issues associated with target coupling. These general perceptions have encouraged a search for alternatives to the present systems. The search for new lasers has been directed generally towards shorter wavelengths; most of the new lasers discovered in the past few years have been in the visible and ultraviolet region of the spectrum. Virtually all of them have been advocated as the most promising candidate for a fusion driver at one time or another

  4. Genetic variation in the NBS1, MRE11, RAD50 and BLM genes and susceptibility to non-Hodgkin lymphoma

    Directory of Open Access Journals (Sweden)

    Gascoyne Randy D

    2009-11-01

    Full Text Available Abstract Background Translocations are hallmarks of non-Hodgkin lymphoma (NHL genomes. Because lymphoid cell development processes require the creation and repair of double stranded breaks, it is not surprising that disruption of this type of DNA repair can cause cancer. The members of the MRE11-RAD50-NBS1 (MRN complex and BLM have central roles in maintenance of DNA integrity. Severe mutations in any of these genes cause genetic disorders, some of which are characterized by increased risk of lymphoma. Methods We surveyed the genetic variation in these genes in constitutional DNA of NHL patients by means of gene re-sequencing, then conducted genetic association tests for susceptibility to NHL in a population-based collection of 797 NHL cases and 793 controls. Results 114 SNPs were discovered in our sequenced samples, 61% of which were novel and not previously reported in dbSNP. Although four variants, two in RAD50 and two in NBS1, showed association results suggestive of an effect on NHL, they were not significant after correction for multiple tests. Conclusion These results suggest an influence of RAD50 and NBS1 on susceptibility to diffuse large B-cell lymphoma and marginal zone lymphoma. Larger association and functional studies could confirm such a role.

  5. Highly potent antimicrobial peptides from N-terminal membrane-binding region of E. coli MreB.

    Science.gov (United States)

    Saikia, Karabi; Sravani, Yalavarthi Durga; Ramakrishnan, Vibin; Chaudhary, Nitin

    2017-02-23

    Microbial pathogenesis is a serious health concern. The threat escalates as the existing conventional antimicrobials are losing their efficacy against the evolving pathogens. Peptides hold promise to be developed into next-generation antibiotics. Antimicrobial peptides adopt amphipathic structures that could selectively bind to and disrupt the microbial membranes. Interaction of proteins with membranes is central to all living systems and we reasoned that the membrane-binding domains in microbial proteins could be developed into efficient antimicrobials. This is an interesting approach as self-like sequences could elude the microbial strategies of degrading the antimicrobial peptides, one of the mechanisms of showing resistance to antimicrobials. We selected the 9-residue-long membrane-binding region of E. coli MreB protein. The 9-residue peptide (C-terminal amide) and its N-terminal acetylated analog displayed broad-spectrum activity, killing Gram-negative bacteria, Gram-positive bacteria, and fungi. Extension with a tryptophan residue at the N-terminus drastically improved the activity of the peptides with lethal concentrations ≤10 μM against all the organisms tested. The tryptophan-extended peptides caused complete killing of C. albicans as well as gentamicin and methicillin resistant S. aureus at 5 μM concentration. Lipid-binding studies and electron microscopic analyses of the peptide-treated microbes suggest membrane disruption as the mechanism of killing.

  6. A holistic perspective on corporate sustainability drivers

    NARCIS (Netherlands)

    Lozano, R.

    2013-01-01

    Since company boards are increasingly discussing 'sustainability', it becomes necessary to examine the nature of sustainability drivers. Most approaches to corporate sustainability drivers have focused either on internal or external drivers. This paper is aimed at providing a more holistic

  7. A holistic perspective on corporate sustainability drivers

    NARCIS (Netherlands)

    Lozano, Rodrigo|info:eu-repo/dai/nl/36412380X

    2015-01-01

    Since company boards are increasingly discussing 'sustainability', it becomes necessary to examine the nature of sustainability drivers. Most approaches to corporate sustainability drivers have focused either on internal or external drivers. This paper is aimed at providing a more holistic

  8. Heavy-ion driver design and scaling

    International Nuclear Information System (INIS)

    Bieri, R.; Monsler, M.; Meier, W.; Stewart, L.

    1992-01-01

    Parametric models for scaling heavy-ion driver designs are described. Scaling of target performance and driver cost is done for driver parameters including driver energy, number of beams, type of superconductor used in focusing magnets, maximum magnetic field allowed at the superconducting windings, linear quadrupole array packing fraction mass, and ion charge state. The cumulative accelerator voltage and beam currents are determined from the Maschke limits on beam current for each choice of driver energy and post-acceleration pulse duration. The heavy-ion driver is optimized over the large available driver parameter space. Parametric studies and the choice of a base driver model are described in a companion paper

  9. Schoolbus driver performance can be improved with driver training ...

    African Journals Online (AJOL)

    The Safe Travel to School Programme was recently implemented by a national child safety agency, with a focus on driver road safety awareness, defensive ... of a vehicle telematics tracking system with regular, individual driving behaviour ...

  10. DNA double strand break repair in mammalian cells: role of MRE11 and BLM proteins at the initiation of Non Homologous End Joining (NHEJ)

    International Nuclear Information System (INIS)

    Grabarz, Anastazja

    2011-01-01

    DNA double strand breaks (DSBs) are highly cytotoxic lesions, which can lead to genetic rearrangements. Two pathways are responsible for repairing these lesions: homologous recombination (HR) and non homologous end joining (NHEJ). In our laboratory, an intrachromosomal substrate has been established in order to measure the efficiency and the fidelity of NHEJ in living cells (Guirouilh-Barbat 2004). This approach led us to identify a KU-independent alternative pathway, which uses micro homologies in the proximity of the junction to accomplish repair - the alternative NHEJ (Guirouilh-Barbat 2004, Guirouilh-Barbat et Rass 2007). The goal of my thesis consisted in identifying and characterising major actors of this pathway. In the absence of KU, alternative NHEJ would be initiated by ssDNA resection of damaged ends. We showed that the nuclease activity of MRE11 is necessary for this mechanism. MRE11 overexpression leads to a two fold stimulation of NHEJ efficiency, while the extinction of MRE11 by siRNA results in a two fold decrease. Our results demonstrate that the proteins RAD50 and CtIP act in the same pathway as MRE11. Moreover, in cells deficient for XRCC4, MIRIN - an inhibitor of the MRN complex - leads to a decrease in repair efficiency, implicating MRE11 in alternative NHEJ. We also showed that MRE11 can act in an ATM-dependent and independent manner (Rass et Grabarz Nat Struct Mol Biol 2009). The initiation of break resection needs to be pursued by a more extensive degradation of DNA, which is accomplished in yeast by the proteins Exo1 and Sgs1/Dna2. In human cells, in vitro studies have recently proposed a similar model of a two-step break resection. We chose to elucidate the role of one of the human homologs of Sgs1 - the RecQ helicase BLM - in the resection process. Our experiments show, that he absence of BLM decreases the efficiency of end joining by NHEJ, accompanied by an increase in error-prone events, especially long-range deletions (≥200 nt). This

  11. Alcohol and older drivers' crashes.

    Science.gov (United States)

    2014-09-01

    Researchers have examined the effects of alcohol consumption : on older adults functioning, and some have : addressed alcohols effects on older drivers crash risk. : Generally, the findings have shown that alcohol is less : likely to be a fa...

  12. Research on driver fatigue detection

    Science.gov (United States)

    Zhang, Ting; Chen, Zhong; Ouyang, Chao

    2018-03-01

    Driver fatigue is one of the main causes of frequent traffic accidents. In this case, driver fatigue detection system has very important significance in avoiding traffic accidents. This paper presents a real-time method based on fusion of multiple facial features, including eye closure, yawn and head movement. The eye state is classified as being open or closed by a linear SVM classifier trained using HOG features of the detected eye. The mouth state is determined according to the width-height ratio of the mouth. The head movement is detected by head pitch angle calculated by facial landmark. The driver's fatigue state can be reasoned by the model trained by above features. According to experimental results, drive fatigue detection obtains an excellent performance. It indicates that the developed method is valuable for the application of avoiding traffic accidents caused by driver's fatigue.

  13. Teen driver cell phone blocker.

    Science.gov (United States)

    2012-02-01

    This study was a randomized control intervention to measure the effectiveness of a cellular phone control device : that communicates with the vehicles of teen drivers to deny them access to their phone while driving for the : purpose of reducing dist...

  14. Combining coordination of motion actuators with driver steering interaction.

    Science.gov (United States)

    Tagesson, Kristoffer; Laine, Leo; Jacobson, Bengt

    2015-01-01

    A new method is suggested for coordination of vehicle motion actuators; where driver feedback and capabilities become natural elements in the prioritization. The method is using a weighted least squares control allocation formulation, where driver characteristics can be added as virtual force constraints. The approach is in particular suitable for heavy commercial vehicles that in general are over actuated. The method is applied, in a specific use case, by running a simulation of a truck applying automatic braking on a split friction surface. Here the required driver steering angle, to maintain the intended direction, is limited by a constant threshold. This constant is automatically accounted for when balancing actuator usage in the method. Simulation results show that the actual required driver steering angle can be expected to match the set constant well. Furthermore, the stopping distance is very much affected by this set capability of the driver to handle the lateral disturbance, as expected. In general the capability of the driver to handle disturbances should be estimated in real-time, considering driver mental state. By using the method it will then be possible to estimate e.g. stopping distance implied from this. The setup has the potential of even shortening the stopping distance, when the driver is estimated as active, this compared to currently available systems. The approach is feasible for real-time applications and requires only measurable vehicle quantities for parameterization. Examples of other suitable applications in scope of the method would be electronic stability control, lateral stability control at launch and optimal cornering arbitration.

  15. Variations in Mre11/Rad50/Nbs1 status and DNA damage-induced S-phase arrest in the cell lines of the NCI60 panel

    Directory of Open Access Journals (Sweden)

    Eastman Alan

    2011-05-01

    Full Text Available Abstract Background The Mre11/Rad50/Nbs1 (MRN complex is a regulator of cell cycle checkpoints and DNA repair. Defects in MRN can lead to defective S-phase arrest when cells are damaged. Such defects may elicit sensitivity to selected drugs providing a chemical synthetic lethal interaction that could be used to target therapy to tumors with these defects. The goal of this study was to identify these defects in the NCI60 panel of cell lines and identify compounds that might elicit selective cytotoxicity. Methods We screened the NCI60 panel in search of cell lines that express low levels of MRN proteins, or that fail to arrest in S-phase in response to the topisomerase I inhibitor SN38. The NCI COMPARE program was used to discover compounds that preferentially target cells with these phenotypes. Results HCT116 cells were initially identified as defective in MRN and S phase arrest. Transfection with Mre11 also elevated Rad50 and Nbs1, and rescued the defective S-phase arrest. Cells of the NCI60 panel exhibited a large range of protein expression but a strong correlation existed between Mre11, Rad50 and Nbs1 consistent with complex formation determining protein stability. Mre11 mRNA correlated best with protein level suggesting it was the primary determinant of the overall level of the complex. Three other cell lines failed to arrest in response to SN38, two of which also had low MRN. However, other cell lines with low MRN still arrested suggesting low MRN does not predict an inability to arrest. Many compounds, including a family of benzothiazoles, correlated with the failure to arrest in S phase. The activity of benzothiazoles has been attributed to metabolic activation and DNA alkylation, but we note several cell lines in which sensitivity does not correlate with metabolism. We propose that the checkpoint defect imposes an additional mechanism of sensitivity on cells. Conclusions We have identified cells with possible defects in the MRN complex

  16. Coincident resection at both ends of random, γ-induced double-strand breaks requires MRX (MRN, Sae2 (Ctp1, and Mre11-nuclease.

    Directory of Open Access Journals (Sweden)

    James W Westmoreland

    2013-03-01

    Full Text Available Resection is an early step in homology-directed recombinational repair (HDRR of DNA double-strand breaks (DSBs. Resection enables strand invasion as well as reannealing following DNA synthesis across a DSB to assure efficient HDRR. While resection of only one end could result in genome instability, it has not been feasible to address events at both ends of a DSB, or to distinguish 1- versus 2-end resections at random, radiation-induced "dirty" DSBs or even enzyme-induced "clean" DSBs. Previously, we quantitatively addressed resection and the role of Mre11/Rad50/Xrs2 complex (MRX at random DSBs in circular chromosomes within budding yeast based on reduced pulsed-field gel electrophoretic mobility ("PFGE-shift". Here, we extend PFGE analysis to a second dimension and demonstrate unique patterns associated with 0-, 1-, and 2-end resections at DSBs, providing opportunities to examine coincidence of resection. In G2-arrested WT, Δrad51 and Δrad52 cells deficient in late stages of HDRR, resection occurs at both ends of γ-DSBs. However, for radiation-induced and I-SceI-induced DSBs, 1-end resections predominate in MRX (MRN null mutants with or without Ku70. Surprisingly, Sae2 (Ctp1/CtIP and Mre11 nuclease-deficient mutants have similar responses, although there is less impact on repair. Thus, we provide direct molecular characterization of coincident resection at random, radiation-induced DSBs and show that rapid and coincident initiation of resection at γ-DSBs requires MRX, Sae2 protein, and Mre11 nuclease. Structural features of MRX complex are consistent with coincident resection being due to an ability to interact with both DSB ends to directly coordinate resection. Interestingly, coincident resection at clean I-SceI-induced breaks is much less dependent on Mre11 nuclease or Sae2, contrary to a strong dependence on MRX complex, suggesting different roles for these functions at "dirty" and clean DSB ends. These approaches apply to resection at

  17. Variations in Mre11/Rad50/Nbs1 status and DNA damage-induced S-phase arrest in the cell lines of the NCI60 panel

    International Nuclear Information System (INIS)

    Garner, Kristen M; Eastman, Alan

    2011-01-01

    The Mre11/Rad50/Nbs1 (MRN) complex is a regulator of cell cycle checkpoints and DNA repair. Defects in MRN can lead to defective S-phase arrest when cells are damaged. Such defects may elicit sensitivity to selected drugs providing a chemical synthetic lethal interaction that could be used to target therapy to tumors with these defects. The goal of this study was to identify these defects in the NCI60 panel of cell lines and identify compounds that might elicit selective cytotoxicity. We screened the NCI60 panel in search of cell lines that express low levels of MRN proteins, or that fail to arrest in S-phase in response to the topisomerase I inhibitor SN38. The NCI COMPARE program was used to discover compounds that preferentially target cells with these phenotypes. HCT116 cells were initially identified as defective in MRN and S phase arrest. Transfection with Mre11 also elevated Rad50 and Nbs1, and rescued the defective S-phase arrest. Cells of the NCI60 panel exhibited a large range of protein expression but a strong correlation existed between Mre11, Rad50 and Nbs1 consistent with complex formation determining protein stability. Mre11 mRNA correlated best with protein level suggesting it was the primary determinant of the overall level of the complex. Three other cell lines failed to arrest in response to SN38, two of which also had low MRN. However, other cell lines with low MRN still arrested suggesting low MRN does not predict an inability to arrest. Many compounds, including a family of benzothiazoles, correlated with the failure to arrest in S phase. The activity of benzothiazoles has been attributed to metabolic activation and DNA alkylation, but we note several cell lines in which sensitivity does not correlate with metabolism. We propose that the checkpoint defect imposes an additional mechanism of sensitivity on cells. We have identified cells with possible defects in the MRN complex and S phase arrest, and a series of compounds that may

  18. Adaptive object placement for augmented reality use in driver assistance systems

    OpenAIRE

    Bordes, Lucie; Breckon, Toby P.; Katramados, Ioannis; Kheyrollahi, Alireza

    2011-01-01

    We present an approach for adaptive object placement for Augmented Reality (AR) use in driver assistance systems. Combined vanishing point and road surface detection enable the real-time adaptive emplacement of AR objects within a drivers' natural field of view for on-road information display. This work combines both automotive vision and multimedia production aspects of real-time visual engineering.

  19. Driver style and driver skills – clustering drivers differing in their potential danger in traffic

    DEFF Research Database (Denmark)

    Martinussen, Laila Marianne; Møller, Mette; Prato, Carlo Giacomo

    The Driver Behavior Questionnaire (DBQ) and the Driver Skill Inventory (DSI) are two of the most frequently used measures of driving style and driving skill. The motivation behind the present study was to test drivers’ insight into their own driving ability based on a combined use of the DBQ......, annual mileage and accident involvement. 3908 drivers aged 18–84 participated in the survey. The results suggested that the drivers have good insight into their own driving ability, as the driving skill level mirrored the frequency of aberrant driving behaviors. K-means cluster analysis revealed four...... distinct clusters that differed in the frequency of aberrant driving behavior and driving skills, as well as individual characteristics and driving related factors such as annual mileage, accident frequency and number of tickets and fines. Thus, two sub-groups were identified as more unsafe than the two...

  20. Chlamydia trachomatis protein CT009 is a structural and functional homolog to the key morphogenesis component RodZ and interacts with division septal plane localized MreB

    OpenAIRE

    Kemege, Kyle E.; Hickey, John M.; Barta, Michael L.; Wickstrum, Jason; Balwalli, Namita; Lovell, Scott; Battaile, Kevin P.; Hefty, P. Scott

    2014-01-01

    Cell division in Chlamydiae is poorly understood as apparent homologs to most conserved bacterial cell division proteins are lacking and presence of elongation (rod shape) associated proteins indicate non-canonical mechanisms may be employed. The rod-shape determining protein MreB has been proposed as playing a unique role in chlamydial cell division. In other organisms, MreB is part of an elongation complex that requires RodZ for proper function. A recent study reported that the protein enco...

  1. Locomotor diseases among male long-haul truck drivers and other professional drivers

    DEFF Research Database (Denmark)

    Jensen, Anker; Kaerlev, Linda; Tüchsen, Finn

    2007-01-01

    -249) and for other truck drivers (SHR: 130, 95% CI: 108-156) compared to bus drivers (SHR: 110, 95% CI: 79-149). All drivers had high SHR for lesions of the ulnar nerve (SHR: 159, 95% CI: 119-207), especially bus drivers (SHR: 197, 95% CI: 116-311). Long-haul truck drivers had high SHRs for synovitis and bursitis...

  2. Synoptic and meteorological drivers of extreme ozone concentrations over Europe

    Science.gov (United States)

    Otero, Noelia Felipe; Sillmann, Jana; Schnell, Jordan L.; Rust, Henning W.; Butler, Tim

    2016-04-01

    The present work assesses the relationship between local and synoptic meteorological conditions and surface ozone concentration over Europe in spring and summer months, during the period 1998-2012 using a new interpolated data set of observed surface ozone concentrations over the European domain. Along with local meteorological conditions, the influence of large-scale atmospheric circulation on surface ozone is addressed through a set of airflow indices computed with a novel implementation of a grid-by-grid weather type classification across Europe. Drivers of surface ozone over the full distribution of maximum daily 8-hour average values are investigated, along with drivers of the extreme high percentiles and exceedances or air quality guideline thresholds. Three different regression techniques are applied: multiple linear regression to assess the drivers of maximum daily ozone, logistic regression to assess the probability of threshold exceedances and quantile regression to estimate the meteorological influence on extreme values, as represented by the 95th percentile. The relative importance of the input parameters (predictors) is assessed by a backward stepwise regression procedure that allows the identification of the most important predictors in each model. Spatial patterns of model performance exhibit distinct variations between regions. The inclusion of the ozone persistence is particularly relevant over Southern Europe. In general, the best model performance is found over Central Europe, where the maximum temperature plays an important role as a driver of maximum daily ozone as well as its extreme values, especially during warmer months.

  3. IFE Power Plant design principles. Drivers. Solid state laser drivers

    International Nuclear Information System (INIS)

    Nakai, S.; Andre, M.; Krupke, W.F.; Mak, A.A.; Soures, J.M.; Yamanaka, M.

    1995-01-01

    The present status of solid state laser drivers for an inertial confinement thermonuclear fusion power plant is discussed. In particular, the feasibility of laser diode pumped solid state laser drivers from both the technical and economic points of view is briefly reviewed. Conceptual design studies showed that they can, in principle, satisfy the design requirements. However, development of new solid state materials with long fluorescence lifetimes and good thermal characteristics is a key issue for laser diode pumped solid state lasers. With the advent of laser diode pumping many materials which were abandoned in the past can presently be reconsidered as viable candidates. It is also concluded that it is important to examine the technical requirements for solid state lasers in relation to target performance criteria. The progress of laser diode pumped lasers in industrial applications should also be closely watched to provide additional information on the economic feasibility of this type of driver. 15 refs, 9 figs, 2 tabs

  4. Sexual behavior among truck drivers.

    Science.gov (United States)

    Singh, Rajiv Kumar; Joshi, Hari Shankar

    2012-01-01

    A cross-sectional study was conducted on Lucknow highway in Bareilly district of Uttar Pradesh to study the knowledge of truck drivers about HIV transmission and prevention and to study the sexual behaviour of these drivers with reference to HIV/AIDS. Age, marital status, education, income, drinking alcohol, length of stay away from home, knowledge about transmission and prevention of HIV, and HIV-prone behavior of truck drivers were studied. Chi-square, mean, and SD were calculated. In all, 289 (97.6%) drivers had heard about HIV/AIDS. Only 242 (81.8%) were aware of HIV transmission by heterosexual route. Misconceptions such as HIV transmission by mosquito bites, living in same room, shaking hands, and sharing food were found. Out of 174 (58.8%) who visited Commercial Sex Workers (CSW), 146 (83.9%) used a condom. 38 (12.8%) visited more than 5 CSW in the last 3 months. Time away from home on the road, marital status, alcohol use, and income class were associated with visiting CSW. High-risk behavior was established in the study population. Safe sex and use of condoms need to be promoted among the truck drivers and better condom availability needs to be assured on highways.

  5. A Role for BLM in Double-Strand Break Repair Pathway Choice: Prevention of CtIP/Mre11-Mediated Alternative Nonhomologous End-Joining

    DEFF Research Database (Denmark)

    Grabarz, Anastazja; Guirouilh-Barbat, Josée; Barascu, Aurelia

    2013-01-01

    The choice of the appropriate double-strand break (DSB) repair pathway is essential for the maintenance of genomic stability. Here, we show that the Bloom syndrome gene product, BLM, counteracts CtIP/MRE11-dependent long-range deletions (>200 bp) generated by alternative end-joining (A-EJ). BLM...... represses A-EJ in an epistatic manner with 53BP1 and RIF1 and is required for ionizing-radiation-induced 53BP1 focus assembly. Conversely, in the absence of 53BP1 or RIF1, BLM promotes formation of A-EJ long deletions, consistent with a role for BLM in DSB end resection. These data highlight a dual role...... for BLM that influences the DSB repair pathway choice: (1) protection against CtIP/MRE11 long-range deletions associated with A-EJ and (2) promotion of DNA resection. These antagonist roles can be regulated, according to cell-cycle stage, by interacting partners such as 53BP1 and TopIII, to avoid...

  6. Pathogenic Chlamydia Lack a Classical Sacculus but Synthesize a Narrow, Mid-cell Peptidoglycan Ring, Regulated by MreB, for Cell Division.

    Science.gov (United States)

    Liechti, George; Kuru, Erkin; Packiam, Mathanraj; Hsu, Yen-Pang; Tekkam, Srinivas; Hall, Edward; Rittichier, Jonathan T; VanNieuwenhze, Michael; Brun, Yves V; Maurelli, Anthony T

    2016-05-01

    The peptidoglycan (PG) cell wall is a peptide cross-linked glycan polymer essential for bacterial division and maintenance of cell shape and hydrostatic pressure. Bacteria in the Chlamydiales were long thought to lack PG until recent advances in PG labeling technologies revealed the presence of this critical cell wall component in Chlamydia trachomatis. In this study, we utilize bio-orthogonal D-amino acid dipeptide probes combined with super-resolution microscopy to demonstrate that four pathogenic Chlamydiae species each possess a ≤ 140 nm wide PG ring limited to the division plane during the replicative phase of their developmental cycles. Assembly of this PG ring is rapid, processive, and linked to the bacterial actin-like protein, MreB. Both MreB polymerization and PG biosynthesis occur only in the intracellular form of pathogenic Chlamydia and are required for cell enlargement, division, and transition between the microbe's developmental forms. Our kinetic, molecular, and biochemical analyses suggest that the development of this limited, transient, PG ring structure is the result of pathoadaptation by Chlamydia to an intracellular niche within its vertebrate host.

  7. Pathogenic Chlamydia Lack a Classical Sacculus but Synthesize a Narrow, Mid-cell Peptidoglycan Ring, Regulated by MreB, for Cell Division.

    Directory of Open Access Journals (Sweden)

    George Liechti

    2016-05-01

    Full Text Available The peptidoglycan (PG cell wall is a peptide cross-linked glycan polymer essential for bacterial division and maintenance of cell shape and hydrostatic pressure. Bacteria in the Chlamydiales were long thought to lack PG until recent advances in PG labeling technologies revealed the presence of this critical cell wall component in Chlamydia trachomatis. In this study, we utilize bio-orthogonal D-amino acid dipeptide probes combined with super-resolution microscopy to demonstrate that four pathogenic Chlamydiae species each possess a ≤ 140 nm wide PG ring limited to the division plane during the replicative phase of their developmental cycles. Assembly of this PG ring is rapid, processive, and linked to the bacterial actin-like protein, MreB. Both MreB polymerization and PG biosynthesis occur only in the intracellular form of pathogenic Chlamydia and are required for cell enlargement, division, and transition between the microbe's developmental forms. Our kinetic, molecular, and biochemical analyses suggest that the development of this limited, transient, PG ring structure is the result of pathoadaptation by Chlamydia to an intracellular niche within its vertebrate host.

  8. Examination of supplemental driver training and online basic driver education courses : traffic tech.

    Science.gov (United States)

    2012-08-01

    The first six months of unsupervised driving are the most : hazardous in a novice drivers driving experience. Most : States adopted graduated driver licensing (GDL) systems : to give novice drivers experience in a protective environment, : gradual...

  9. Key drivers of airline loyalty.

    Science.gov (United States)

    Dolnicar, Sara; Grabler, Klaus; Grün, Bettina; Kulnig, Anna

    2011-10-01

    This study investigates drivers of airline loyalty. It contributes to the body of knowledge in the area by investigating loyalty for a number of a priori market segments identified by airline management and by using a method which accounts for the multi-step nature of the airline choice process. The study is based on responses from 687 passengers. Results indicate that, at aggregate level, frequent flyer membership, price, the status of being a national carrier and the reputation of the airline as perceived by friends are the variables which best discriminate between travellers loyal to the airline and those who are not. Differences in drivers of airline loyalty for a number of segments were identified. For example, loyalty programs play a key role for business travellers whereas airline loyalty of leisure travellers is difficult to trace back to single factors. For none of the calculated models satisfaction emerged as a key driver of airline loyalty.

  10. UWB dual burst transmit driver

    Science.gov (United States)

    Dallum, Gregory E [Livermore, CA; Pratt, Garth C [Discovery Bay, CA; Haugen, Peter C [Livermore, CA; Zumstein, James M [Livermore, CA; Vigars, Mark L [Livermore, CA; Romero, Carlos E [Livermore, CA

    2012-04-17

    A dual burst transmitter for ultra-wideband (UWB) communication systems generates a pair of precisely spaced RF bursts from a single trigger event. An input trigger pulse produces two oscillator trigger pulses, an initial pulse and a delayed pulse, in a dual trigger generator. The two oscillator trigger pulses drive a gated RF burst (power output) oscillator. A bias driver circuit gates the RF output oscillator on and off and sets the RF burst packet width. The bias driver also level shifts the drive signal to the level that is required for the RF output device.

  11. YeeU enhances the bundling of cytoskeletal polymers of MreB and FtsZ, antagonizing the CbtA (YeeV) toxicity in Escherichia coli.

    Science.gov (United States)

    Masuda, Hisako; Tan, Qian; Awano, Naoki; Wu, Kuen-Phon; Inouye, Masayori

    2012-06-01

    All free-living bacteria carry the toxin-antitoxin (TA) systems controlling cell growth and death under stress conditions. YeeU-YeeV (CbtA) is one of the Escherichia coli TA systems, and the toxin, CbtA, has been reported to inhibit the polymerization of bacterial cytoskeletal proteins, MreB and FtsZ. Here, we demonstrate that the antitoxin, YeeU, is a novel type of antitoxin (type IV TA system), which does not form a complex with CbtA but functions as an antagonist for CbtA toxicity. Specifically, YeeU was found to directly interact with MreB and FtsZ, and enhance the bundling of their filamentous polymers in vitro. Surprisingly, YeeU neutralized not only the toxicity of CbtA but also the toxicity caused by other inhibitors of MreB and FtsZ, such as A22, SulA and MinC, indicating that YeeU-induced bundling of MreB and FtsZ has an intrinsic global stabilizing effect on their homeostasis. Here we propose to rename YeeU as CbeA for cytoskeleton bundling-enhancing factor A. © 2012 Blackwell Publishing Ltd.

  12. Drivers and Limits for Transport

    DEFF Research Database (Denmark)

    Kristensen, Niels Buus; Nielsen, Thomas A. Sick; Gudmundsson, Henrik

    This report summarizes key outcomes of the study ’Drivers and Limits’ that was supported for the period 2009-2013 by a research grant from the Danish Strategic Research Council. The project investigated - for the empirical context of Denmark - key driving forces behind transport growth, as well...

  13. Modeling taxi driver anticipatory behavior

    NARCIS (Netherlands)

    Zheng, Zhong; Rasouli, S.; Timmermans, H.J.P.

    2018-01-01

    As part of a wider behavioral agent-based model that simulates taxi drivers’ dynamic passenger-finding behavior under uncertainty, we present a model of strategic behavior of taxi drivers in anticipation of substantial time varying demand at locations such as airports and major train stations. The

  14. Driver Psychology during Automated Platooning

    NARCIS (Netherlands)

    Heikoop, D.D.

    2017-01-01

    With the rapid increase in vehicle automation technology, the call for understanding how humans behave while driving in an automated vehicle becomes more urgent. Vehicles that have automated systems such as Lane Keeping Assist (LKA) or Adaptive Cruise Control (ACC) not only support drivers in their

  15. Nonmagnetic driver for piezoelectric actuators

    DEFF Research Database (Denmark)

    Ekhtiari, Marzieh

    2014-01-01

    actuator drive is the only form-fit continuous drive solution currently available for the development of high performance nonmagnetic motors. In this research focus will be on the non magnetic compact high efficiency driver for the piezo actuators and on employing energy recovery from the capacitive...

  16. Free electron laser as a fusion driver

    International Nuclear Information System (INIS)

    Prosnitz, D.; Schlitt, L.

    1981-01-01

    The Free Electron Laser (FEL) is shown to be a potentially attractive solution to the problem of finding a suitable short wavelength fusion driver. The design of a 3 MJ, 250 nm FEL fusion driver is discussed

  17. Anthropogenic Drivers of Ecosystem Change: an Overview

    Directory of Open Access Journals (Sweden)

    Gerald C. Nelson

    2006-12-01

    Full Text Available This paper provides an overview of what the Millennium Ecosystem Assessment (MA calls "indirect and direct drivers" of change in ecosystem services at a global level. The MA definition of a driver is any natural or human-induced factor that directly or indirectly causes a change in an ecosystem. A direct driver unequivocally influences ecosystem processes. An indirect driver operates more diffusely by altering one or more direct drivers. Global driving forces are categorized as demographic, economic, sociopolitical, cultural and religious, scientific and technological, and physical and biological. Drivers in all categories other than physical and biological are considered indirect. Important direct drivers include changes in climate, plant nutrient use, land conversion, and diseases and invasive species. This paper does not discuss natural drivers such as climate variability, extreme weather events, or volcanic eruptions.

  18. 49 CFR 396.13 - Driver inspection.

    Science.gov (United States)

    2010-10-01

    ... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS INSPECTION, REPAIR, AND MAINTENANCE § 396.13 Driver inspection. Before driving a motor vehicle, the driver shall: (a) Be satisfied that the motor vehicle is in safe operating condition; (b) Review the last driver vehicle inspection...

  19. School Bus Accidents and Driver Age.

    Science.gov (United States)

    McMichael, Judith

    The study examines the rates and types of school bus accidents according to the age of the school bus driver. Accident rates in North Carolina for the school year 1971-72 were analyzed using three sources of data: accident reports, driver and mileage data, and questionnaires administered to a sample of school bus drivers. Data were obtained on…

  20. among Taxi Drivers in Addis Ababa, Ethiopia

    African Journals Online (AJOL)

    user

    Long years of driving [AOR =4.6 (95%CI, 1.6-12.9)], involvement in a similar activity prior to becoming taxi driver .... full time taxi driver; produce a valid driving license; .... Self-employee .... professional car drivers in Dhaka city, Bangladesh.

  1. Aktivnosti i društvene mreže u slobodnom vremenu mlađih tinejdžera

    OpenAIRE

    Rattinger, Marija

    2017-01-01

    Slobodno vrijeme učenika je ono vrijeme koje im preostaje nakon svih školskih i obiteljskih obveza. Postoje različite mogućnosti njegovog provođenja i različite mogućnosti utjecaja na način njegovog provođenja ( Byrne i dr., 2006). Ovim se radom istražilo koliko mlađi tinejdžeri imaju slobodnog vremena, na koji način ga koriste, te koliko su online društvene mreže i na koji način zastupljene u slobodnom vremenu ispitivane populacije. Rezultati pokazuju da mlađi tinejdžeri imaju prosječno oko ...

  2. Retrospektiv undersökning av främre korsbandsskada hos fotbollsspelande damer på liganivå i Finland

    OpenAIRE

    Widjeskog, Maria

    2013-01-01

    Främre korsbandsskador är en av de vanligaste allvarliga skadorna bland kvinnliga fotbollsspelare och leder till minst 6 månaders uppehåll från tävlingssammanhang. En hel del studier har gjorts inom området. Den här studien försöker få fram riskfaktorer för skada, i hurudana situationer skadan sker, förebyggande möjligheter samt olikheter i rehabilitering. Studien är retrospektiv och 19 spelare deltog. Deltagarna är damfotbollsspelare som spelat ligafotboll i Finland något år mellan åren ...

  3. MRI and MRE for non-invasive quantitative assessment of hepatic steatosis and fibrosis in NAFLD and NASH: Clinical trials to clinical practice

    Science.gov (United States)

    Dulai, Parambir S.; Sirlin, Claude B.; Loomba, Rohit

    2016-01-01

    Nonalcoholic fatty liver disease (NAFLD) represents one of the most common causes of chronic liver disease, and its prevalence is rising worldwide. The occurrence of nonalcoholic steatohepatitis (NASH) is associated with a substantial increase in disease related morbidity and mortality. Accordingly, there has been a surge of innovation surrounding drug development in an effort to off-set the natural progression and long-term risks of this disease. Disease assessment within clinical trials and clinical practice for NAFLD is currently done with liver biopsies. Liver biopsy-based assessments, however, remain imprecise and are not without cost or risk. This carries significant implications for the feasibility and costs of bringing therapeutic interventions to market. A need therefore arises for reliable and highly accurate surrogate end-points that can be used in phase 2 and 3 clinical trials to reduce trial size requirements and costs, while improving feasibility and ease of implementation in clinical practice. Significant advances have now been made in magnetic resonance technology, and magnetic resonance imaging (MRI) and elastrography (MRE) have been demonstrated to be highly accurate diagnostic tools for the detection of hepatic steatosis and fibrosis. In this review article, we will summarize the currently available evidence regarding the use of MRI and MRE among NAFLD patients, and the evolving role these surrogate biomarkers will play in the rapidly advancing arena of clinical trials in NASH and hepatic fibrosis. Furthermore, we will highlight how these tools can be readily applied to routine clinical practice, where the growing burden of NAFLD will need to be met with enhanced monitoring algorithms. PMID:27312947

  4. Factors Contributing to Crashes among Young Drivers

    Directory of Open Access Journals (Sweden)

    Lyndel J. Bates

    2014-08-01

    Full Text Available Young drivers are the group of drivers most likely to crash. There are a number of factors that contribute to the high crash risk experienced by these drivers. While some of these factors are intrinsic to the young driver, such as their age, gender or driving skill, others relate to social factors and when and how often they drive. This article reviews the factors that affect the risk of young drivers crashing to enable a fuller understanding of why this risk is so high in order to assist in developing effective countermeasures.

  5. Visualization drivers for Geant4

    International Nuclear Information System (INIS)

    Beretvas, Andy

    2005-01-01

    This document is on Geant 4 visualization tools (drivers), evaluating pros and cons of each option, including recommendations on which tools to support at Fermilab for different applications. Four visualization drivers are evaluated. They re OpenGL, HepRep, DAWN and VRML. They all have good features, OpenGL provides graphic output with out an intermediate file. HepRep provides menus to assist the user. DAWN provides high quality plots and even for large files produces output quickly. VRML uses the smallest disk space for intermediate files. Large experiments at Fermilab will want to write their own display. They should proceed to make this display graphics independent. Medium experiment will probably want to use HepRep because of it's menu support. Smaller scale experiments will want to use OpenGL in the spirit of having immediate response, good quality output and keeping things simple

  6. Global desertification: Drivers and feedbacks

    Science.gov (United States)

    D'Odorico, Paolo; Bhattachan, Abinash; Davis, Kyle F.; Ravi, Sujith; Runyan, Christiane W.

    2013-01-01

    Desertification is a change in soil properties, vegetation or climate, which results in a persistent loss of ecosystem services that are fundamental to sustaining life. Desertification affects large dryland areas around the world and is a major cause of stress in human societies. Here we review recent research on the drivers, feedbacks, and impacts of desertification. A multidisciplinary approach to understanding the drivers and feedbacks of global desertification is motivated by our increasing need to improve global food production and to sustainably manage ecosystems in the context of climate change. Classic desertification theories look at this process as a transition between stable states in bistable ecosystem dynamics. Climate change (i.e., aridification) and land use dynamics are the major drivers of an ecosystem shift to a “desertified” (or “degraded”) state. This shift is typically sustained by positive feedbacks, which stabilize the system in the new state. Desertification feedbacks may involve land degradation processes (e.g., nutrient loss or salinization), changes in rainfall regime resulting from land-atmosphere interactions (e.g., precipitation recycling, dust emissions), or changes in plant community composition (e.g., shrub encroachment, decrease in vegetation cover). We analyze each of these feedback mechanisms and discuss their possible enhancement by interactions with socio-economic drivers. Large scale effects of desertification include the emigration of “environmental refugees” displaced from degraded areas, climatic changes, and the alteration of global biogeochemical cycles resulting from the emission and long-range transport of fine mineral dust. Recent research has identified some possible early warning signs of desertification, which can be used as indicators of resilience loss and imminent shift to desert-like conditions. We conclude with a brief discussion on some desertification control strategies implemented in different

  7. Driver competence performance indicators using OTMR

    Energy Technology Data Exchange (ETDEWEB)

    Hassan EL Rashidy, R.A.

    2016-07-01

    The current practice for assessing driver competence performance is in-cab riding by driver managers. However, this paper investigates whether real-world driving data extracted from on-train monitoring recorders data (OTMR) can be used to assess the driver performance. A number of indicators were used to evaluate the drivers’ performance. These include: their use of the emergency bypass switch, the driver's reminder appliance as well as the driver’s reaction time. A study case illustrated the applicability of OTMR data to estimate the proposed indicators, which suggests that the indicators can be useful in the driver management system in addition to the current indicators. Furthermore, the proposed indicators could be used to tailor the driver training schemes up to their individual needs and evaluate their effectiveness. They could even be used for improving driver competence performance and reducing crash involvement by revealing potentially detrimental driving performance. (Author)

  8. Advancing the integration of spatial data to map human and natural drivers on coral reefs

    Science.gov (United States)

    Gove, Jamison M.; Walecka, Hilary R.; Donovan, Mary K.; Williams, Gareth J.; Jouffray, Jean-Baptiste; Crowder, Larry B.; Erickson, Ashley; Falinski, Kim; Friedlander, Alan M.; Kappel, Carrie V.; Kittinger, John N.; McCoy, Kaylyn; Norström, Albert; Nyström, Magnus; Oleson, Kirsten L. L.; Stamoulis, Kostantinos A.; White, Crow; Selkoe, Kimberly A.

    2018-01-01

    A major challenge for coral reef conservation and management is understanding how a wide range of interacting human and natural drivers cumulatively impact and shape these ecosystems. Despite the importance of understanding these interactions, a methodological framework to synthesize spatially explicit data of such drivers is lacking. To fill this gap, we established a transferable data synthesis methodology to integrate spatial data on environmental and anthropogenic drivers of coral reefs, and applied this methodology to a case study location–the Main Hawaiian Islands (MHI). Environmental drivers were derived from time series (2002–2013) of climatological ranges and anomalies of remotely sensed sea surface temperature, chlorophyll-a, irradiance, and wave power. Anthropogenic drivers were characterized using empirically derived and modeled datasets of spatial fisheries catch, sedimentation, nutrient input, new development, habitat modification, and invasive species. Within our case study system, resulting driver maps showed high spatial heterogeneity across the MHI, with anthropogenic drivers generally greatest and most widespread on O‘ahu, where 70% of the state’s population resides, while sedimentation and nutrients were dominant in less populated islands. Together, the spatial integration of environmental and anthropogenic driver data described here provides a first-ever synthetic approach to visualize how the drivers of coral reef state vary in space and demonstrates a methodological framework for implementation of this approach in other regions of the world. By quantifying and synthesizing spatial drivers of change on coral reefs, we provide an avenue for further research to understand how drivers determine reef diversity and resilience, which can ultimately inform policies to protect coral reefs. PMID:29494613

  9. Driving fatigue in professional drivers: a survey of truck and taxi drivers.

    Science.gov (United States)

    Meng, Fanxing; Li, Shuling; Cao, Lingzhi; Li, Musen; Peng, Qijia; Wang, Chunhui; Zhang, Wei

    2015-01-01

    Fatigue among truck drivers has been studied extensively; however, less is known regarding the fatigue experience of taxi drivers in heavily populated metropolitan areas. This study aimed to compare the differences and similarities between truck and taxi driver fatigue to provide implications for the fatigue management and education of professional drivers. A sample of 274 truck drivers and 286 taxi drivers in Beijing was surveyed via a questionnaire, which included items regarding work characteristics, fatigue experience, accident information, attitude toward fatigue, and methods of counteracting fatigue. Driver fatigue was prevalent among professional drivers, and it was even more serious for taxi drivers. Taxi drivers reported more frequent fatigue experiences and were involved in more accidents. Among the contributing factors to fatigue, prolonged driving time was the most important factor identified by both driver groups. Importantly, the reason for the engagement in prolonged driving was neither due to the lack of awareness concerning the serious outcome of fatigue driving nor because of their poor detection of fatigue. The most probable reason was the optimism bias, as a result of which these professional drivers thought that fatigue was more serious for other drivers than for themselves, and they thought that they were effective in counteracting the effect of fatigue on their driving performance. Moreover, truck drivers tended to employ methods that require stopping to counteract fatigue, whereas taxi drivers preferred methods that were simultaneous with driving. Although both driver groups considered taking a nap as one of the most effective means to address fatigue, this method was not commonly used. Interestingly, these drivers were aware that the methods they frequently used were not the most effective means to counteract fatigue. This study provides knowledge on truck and taxi drivers' characteristics in fatigue experience, fatigue attitude, and

  10. Experimental Research in Boost Driver with EDLCs

    Science.gov (United States)

    Matsumoto, Hirokazu

    The supply used in servo systems tends to have a high voltage in order to reduce loss and improve the response of motor drives. We propose a new boost motor driver that comprises EDLCs. The proposed driver has a simple structure, wherein the EDLCs are connected in series to the supply, and comprises a charge circuit to charge the EDLCs. The proposed driver has three advantages over conventional boost drivers. The first advantage is that the driver can easily attain the stable boost voltage. The second advantage is that the driver can reduce input power peaks. In a servo system, the input power peaks become greater than the rated power in order to accelerate the motor rapidly. This implies that the equipments that supply power to servo systems must have sufficient power capacity to satisfy the power peaks. The proposed driver can suppress the increase of the power capacity of supply facilities. The third advantage is that the driver can store almost all of the regenerative energy. Conventional drivers have a braking resistor to suppress the increase in the DC link voltage. This causes a considerable reduction in the efficiency. The proposed driver is more efficient than conventional drivers. In this study, the experimental results confirmed the effectiveness of the proposed driver and showed that the drive performance of the proposed driver is the same as that of a conventional driver. Furthermore, it was confirmed that the results of the simulation of a model of the EDLC module, whose capacitance is dependent on the frequency, correspond well with the experimental results.

  11. Disk generator with nearly shockless accelerated driver plate

    International Nuclear Information System (INIS)

    Fowler, C.M.; Hoeberling, R.F.; Marsh, S.P.

    1990-01-01

    The disk generator, shown in this paper, was first conceived as a useful magnetic field source for a class of in situ plasma experiments. Initial current is supplied (from a capacitor bank) to the generator through radial coaxial cables. It enters the top plate, passes through the central post, and exists through the top of the outer cylindrical glide surface, which is insulated from the top plate. The explosive over the top plate is initiated simultaneously over its upper surface at such a time that the top plate starts its downward motion at about peak initial current. Several conditions were required for the experiments under consideration: the top or driver plate should contact the bottom plate nearly parallel to it; the generator interior should be evacuated; microjetting debris (fluff) arising from the driver plate should be held to a minimum; currents developed should be several tens of megamperes, with values of dI/dt exceeding 10 13 A/s

  12. Assessment of early onset of driver fatigue using multimodal fatigue measures in a static simulator.

    Science.gov (United States)

    Jagannath, M; Balasubramanian, Venkatesh

    2014-07-01

    Driver fatigue is an important contributor to road accidents. This paper reports a study that evaluated driver fatigue using multimodal fatigue measures, i.e., surface electromyography (sEMG), electroencephalography (EEG), seat interface pressure, blood pressure, heart rate and oxygen saturation level. Twenty male participants volunteered in this study by performing 60 min of driving on a static simulator. Results from sEMG showed significant physical fatigue (ρ fatigue. This will help us understand the influence of physical and mental fatigue on driver during monotonous driving. Copyright © 2014 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  13. Driver style and driver skill – Clustering sub-groups of drivers differing in their potential danger in traffic

    DEFF Research Database (Denmark)

    Martinussen, Laila Marianne; Møller, Mette; Prato, Carlo Giacomo

    The Driver Behavior Questionnaire (DBQ) and the Driver Skill Inventory (DSI) are two of the most frequently used measures of self-reported driving style and driving skill. The motivation behind the present study was to test drivers’ consistency or judgment of their own self-reported driving ability...... based on a combined use of the DBQ and the DSI. Moreover, the joint use of the two instruments was applied to identify sub-groups of drivers that differ in their potential danger in traffic (as measured by frequency of aberrant driving behaviors and level of driving skills), as well as to test whether...... the sub-groups of drivers differed in characteristics such as age, gender, annual mileage and accident involvement. 3908 drivers aged 18–84 participated in the survey. The results suggested that the drivers are consistent in their reporting of driving ability, as the self-reported driving skill level...

  14. Cognitive characteristics of older Japanese drivers.

    Science.gov (United States)

    Susilowati, Indri H; Yasukouchi, Akira

    2012-02-29

    Some causes of accidents among older drivers are: not paying attention to traffic signals; missing stop lines; and having to deal with and misjudging emergency situations. These causes of accidents reveal problems with attention and cognition. Such incidents are also related to driver perception and stress-coping mechanisms. It is important to examine the relation of stress reactions to attention and cognition as a factor influencing the causes of accidents commonly involving older drivers. Subjects were 10 young drivers (23.3 ± 3.33 years) and 25 older drivers divided into two groups (older1 [60 to 65 years] and older2 [> 65 years]). This study revealed the correlation within driver stress inventory and driver coping questionnaires parameters was observed only in older drivers. They also needed a longer response time for Trail Making Test A and B. The factors affected the attention and cognition of older drivers by age but not driving experience itself, and coping parameters such as emotion focus, reappraisal, and avoidance were not included as stress inventory parameters. Being prone to fatigue was less for younger drivers than older drivers. Because they have shorter distances, shorter drive times, and no need for expressways, older drivers also had a significantly lower risk of thrill-seeking behaviour and more patience. The intervention addressing their attention skills, aggressive feelings, and emotion focus should be considered. The technological improvements in cars will make older drivers feel safer and make driving easier which might lower the attention paid to the road, and regular driving training might be needed to assess and enhance their safety.

  15. Cognitive characteristics of older Japanese drivers

    Directory of Open Access Journals (Sweden)

    Susilowati Indri H

    2012-02-01

    Full Text Available Abstract Background Some causes of accidents among older drivers are: not paying attention to traffic signals; missing stop lines; and having to deal with and misjudging emergency situations. These causes of accidents reveal problems with attention and cognition. Such incidents are also related to driver perception and stress-coping mechanisms. It is important to examine the relation of stress reactions to attention and cognition as a factor influencing the causes of accidents commonly involving older drivers. Finding Subjects were 10 young drivers (23.3 ± 3.33 years and 25 older drivers divided into two groups (older1 [60 to 65 years] and older2 [> 65 years]. This study revealed the correlation within driver stress inventory and driver coping questionnaires parameters was observed only in older drivers. They also needed a longer response time for Trail Making Test A and B. The factors affected the attention and cognition of older drivers by age but not driving experience itself, and coping parameters such as emotion focus, reappraisal, and avoidance were not included as stress inventory parameters. Being prone to fatigue was less for younger drivers than older drivers. Because they have shorter distances, shorter drive times, and no need for expressways, older drivers also had a significantly lower risk of thrill-seeking behaviour and more patience. Conclusion The intervention addressing their attention skills, aggressive feelings, and emotion focus should be considered. The technological improvements in cars will make older drivers feel safer and make driving easier which might lower the attention paid to the road, and regular driving training might be needed to assess and enhance their safety.

  16. Dominant drivers of business students

    Directory of Open Access Journals (Sweden)

    Radu Cătălina

    2017-07-01

    Full Text Available Taibi Kahler wrote in 1974 a theory about five main drivers that could explain people’s motivation and a series of positive and negative behavior patterns: Be Strong, Be Perfect, Hurry Up, Try Hard and Please People. Of course, we consider there is no absolute positive or negative behavior, since (1 everything needs to be analyzed by taking into account the context and (2 any behavior pattern can mean a series of advantages as long as people understand their own values, beliefs, attitudes and behaviors. It would be interesting to link Kahler’s drivers to the educational process, in order to be able to adapt our courses and our teaching styles to students’ requirements and also to the requirements in the labor market. Our paper is built on literature review and a questionnaire applied to a sample of 607 students in Bucharest University of Economic Studies, Romania. Information was processed with Microsoft Excel 2013, in order to look at the main working styles our students have, at the main explanations for the differences between them and in order to test a series of hypotheses. We were interested to look at the main traits of the current generation of students in our university: dominant drivers, roles of managers and specialists, the attractiveness of the entrepreneurial career path, etc. and at a series of patterns (i.e. gender-related differences. We consider results of this study are useful both for teaching and research purposes. In terms of teaching, we plan to adapt our educational methods in order to improve the educational process.

  17. Microprocessor-based stepping motor driver

    International Nuclear Information System (INIS)

    Halbig, J.K.; Klosterbuer, S.F.

    1979-09-01

    The Pion Generation for Medical Irradiations (PIGMI) program at the Los Alamos Scientific Laboratory requires a versatile stepping motor driver to do beam diagnostic measurements. A driver controlled by a microprocessor that can move eight stepping motors simultaneously was designed. The driver can monitor and respond to clockwise- and counterclockwise-limit switches, and it can monitor a 0- to 10-V dc position signal. The software controls start and stop ramping and maximum stepping rates. 2 figures, 1 table

  18. Risk factors affecting fatal bus accident severity: Their impact on different types of bus drivers.

    Science.gov (United States)

    Feng, Shumin; Li, Zhenning; Ci, Yusheng; Zhang, Guohui

    2016-01-01

    While the bus is generally considered to be a relatively safe means of transportation, the property losses and casualties caused by bus accidents, especially fatal ones, are far from negligible. The reasons for a driver to incur fatalities are different in each case, and it is essential to discover the underlying risk factors of bus fatality severity for different types of drivers in order to improve bus safety. The current study investigates the underlying risk factors of fatal bus accident severity to different types of drivers in the U.S. by estimating an ordered logistic model. Data for the analysis are retrieved from the Buses Involved in Fatal Accidents (BIFA) database from the USA for the years 2006-2010. Accidents are divided into three levels by counting their equivalent fatalities, and the drivers are classified into three clusters by the K-means cluster analysis. The analysis shows that some risk factors have the same impact on different types of drivers, they are: (a) season; (b) day of week; (c) time period; (d) number of vehicles involved; (e) land use; (f) manner of collision; (g) speed limit; (h) snow or ice surface condition; (i) school bus; (j) bus type and seating capacity; (k) driver's age; (l) driver's gender; (m) risky behaviors; and (n) restraint system. Results also show that some risk factors only have impact on the "young and elder drivers with history of traffic violations", they are: (a) section type; (b) number of lanes per direction; (c) roadway profile; (d) wet road surface; and (e) cyclist-bus accident. Notably, history of traffic violations has different impact on different types of bus drivers. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. [E75, R78 and D82 of Escherichia coli FtsZ are key residues for FtsZ cellular self-assembly and FtsZ-MreB interaction].

    Science.gov (United States)

    Huo, Yujia; Lu, Qiaonan; Zheng, Xiaowei; Ma, Yuanfang; Lu, Feng

    2016-02-04

    To explore effects of FtsZ mutants FtsZ(E75A), FtsZ(R78G) and FtsZ(D82A) on FtsZ self-assembly and interaction of FtsZ with MreB in Escherichia coli strains. METHODS) We constructed FtsZ and its mutant's plasmids by molecular clone and site-directed mutagenesis methods, and purified targeted proteins by affinity chromatography. QN6(ftsZ::yfp-cat), QN7(tsZ::yfp-cat), QN8(ftsZ(R78G)::yfp-cat) and QN9 (ftsZ(D82A):.:yfp-cat) strains were constructed by linear DNA homologous recombination. We observed cellular localization pattern of FtsZ and its mutants in E. coli by living cell imaging experiments, examined interaction of FtsZ/FtsZ*-FtsZ* and FtsZ/FtsZ*-MreB by Coimmunoprecipitation and bacteria two hybrid, and analyzed assembly characteristics of FtsZ mutants by Light scattering. RESULTS) The Yfp-labeled FtsZ(E75A), FtsZ(R78G) and FtsZ(D82A) mutant proteins failed to assemble into functional Z-ring structure and localize correctly in E. coli strains. Interaction of FtsZ with its mutants, or FtsZ*-FtsZ* and FtsZ*-MreB interaction were weakened or completely disappeared. In addition, in vitro experiments show that E75A, R78G and D82A mutations decreased the polymerization efficiency of FtsZ monomer. FtsZ E75, R78 and D82 are critical amino acids in the assembly, function of FtsZ protein and FtsZ-MreB interaction in E. coli strains.

  20. Economic drivers of mineral supply

    Science.gov (United States)

    Wagner, Lorie A.; Sullivan, Daniel E.; Sznopek, John L.

    2003-01-01

    The debate over the adequacy of future supplies of mineral resources continues in light of the growing use of mineral-based materials in the United States. According to the U.S. Geological Survey, the quantity of new materials utilized each year has dramatically increased from 161 million tons2 in 1900 to 3.2 billion tons in 2000. Of all the materials used during the 20th century in the United States, more than half were used in the last 25 years. With the Earth?s endowment of natural resources remaining constant, and increased demand for resources, economic theory states that as depletion approaches, prices rise. This study shows that many economic drivers (conditions that create an economic incentive for producers to act in a particular way) such as the impact of globalization, technological improvements, productivity increases, and efficient materials usage are at work simultaneously to impact minerals markets and supply. As a result of these economic drivers, the historical price trend of mineral prices3 in constant dollars has declined as demand has risen. When price is measured by the cost in human effort, the price trend also has been almost steadily downward. Although the United States economy continues its increasing mineral consumption trend, the supply of minerals has been able to keep pace. This study shows that in general supply has grown faster than demand, causing a declining trend in mineral prices.

  1. Zaštita računarskih mreža Ministarstva odbrane i Vojske Srbije primenom virtuelnog honeyneta / Security of computer network of the Ministry of Defence and the Serbian Armed Forces using virtual honeynets

    Directory of Open Access Journals (Sweden)

    Zoran Bobar

    2009-07-01

    Full Text Available U ovom radu obrađena je zaštita računarskih mreža u Ministarstvu odbrane i Vojsci Srbije primenom virtuelnog honeyneta. Zaštita je obrađena sa aspekta arhitekture računarskih mreža koje imaju pristup internetu. Predloženi koncept primene virtuelnog honeyneta uzima u obzir dostignuća nauke u ovoj oblasti u svetu, ostale primenjene metode i tehnike zaštite, mogućnosti i potrebe korisnika i elemente delova računarskog sistema Ministarstva odbrane i Vojske koji bi mogli biti meta napada sa udaljenih mesta globalne (internet mreže. / This paper covers the proposed solution for security of computer network in the Ministry of Defence and the Serbian Armed Forces using virtual honeynets. The security is covered from the aspect of the architecture of computer networks with Internet access. The proposed usage of virtual honeynets for protection takes into account the accomplishments of science in this field as well as security methods and techniques, users' needs and opportunities along with the computer network components of the MoD and the SAF that can be targets for attack.

  2. Analiza tačnosti visina bosanskohercegovačke trigonometrijske mreže pomoću GPS/EGM podataka : Accuracy analyses of B&H trigonometric network heights by GPS/EGM data

    Directory of Open Access Journals (Sweden)

    Medžida Mulić

    2012-06-01

    Full Text Available Dostupnost savremenih globalnih geoidnih modela kao i 3D koordinata u globalnom koordinatnom referentnom sistemu omogućava anlazu tačnosti ortometrijskih visina trionometrijske mreže. Rad pokazuje preliminarne rezultate analize tačnosti visina trigonometrijske mreže u Bosni i Hercegovini, a na osnovu usporedbe visina izračunatih korištenjem GPS visina i EGM geoidnih modela. Preliminarni rezultati ukazuju na postojanje grubih pogrešaka u visinama trigonometrijskih tačaka BiH trigonometrijske mreže. : Analysis of the accuracy of the orthometric heights of the old trigonometric points are posible since the global accurate models of geoid as well as 3D coordinates in the global coordinate system became available. Preliminary results of the heights accuracy analyze in the old trigonometric network in the in Bosnia and Herzegovina are shown in this paper. The analyze has done by comparing the orthometric heights calculated using by GPS height and the modern global geoid models EGM, with the old official heights of trigonometric points. The results indicate the existence of blunders among the heights in the old trigonometric network of Bosnia and Herzegovina.

  3. Drivers' reactions to sudden lead car braking under varying workload conditions; towards a driver support system.

    NARCIS (Netherlands)

    Schaap, Nina; van der Horst, A.R.A.; van Arem, Bart; Brookhuis, K.A.

    2008-01-01

    At urban intersections drivers handle multiple tasks simultaneously, making urban driving a complex task. An advanced driver assistance system may support drivers in this specific driving task, but the design details of such a system need to be determined before they can be fully deployed. A driving

  4. Quantifying the drivers of ocean-atmosphere CO2 fluxes

    Science.gov (United States)

    Lauderdale, Jonathan M.; Dutkiewicz, Stephanie; Williams, Richard G.; Follows, Michael J.

    2016-07-01

    A mechanistic framework for quantitatively mapping the regional drivers of air-sea CO2 fluxes at a global scale is developed. The framework evaluates the interplay between (1) surface heat and freshwater fluxes that influence the potential saturated carbon concentration, which depends on changes in sea surface temperature, salinity and alkalinity, (2) a residual, disequilibrium flux influenced by upwelling and entrainment of remineralized carbon- and nutrient-rich waters from the ocean interior, as well as rapid subduction of surface waters, (3) carbon uptake and export by biological activity as both soft tissue and carbonate, and (4) the effect on surface carbon concentrations due to freshwater precipitation or evaporation. In a steady state simulation of a coarse-resolution ocean circulation and biogeochemistry model, the sum of the individually determined components is close to the known total flux of the simulation. The leading order balance, identified in different dynamical regimes, is between the CO2 fluxes driven by surface heat fluxes and a combination of biologically driven carbon uptake and disequilibrium-driven carbon outgassing. The framework is still able to reconstruct simulated fluxes when evaluated using monthly averaged data and takes a form that can be applied consistently in models of different complexity and observations of the ocean. In this way, the framework may reveal differences in the balance of drivers acting across an ensemble of climate model simulations or be applied to an analysis and interpretation of the observed, real-world air-sea flux of CO2.

  5. Water availability as a driver of spatial and temporal variability in vegetation in the La Mancha plain (Spain): Implications for the land-surface energy, water and carbon budget

    Science.gov (United States)

    Los, Sietse

    2017-04-01

    Vegetation is water limited in large areas of Spain and therefore a close link exists between vegetation greenness observed from satellite and moisture availability. Here we exploit this link to infer spatial and temporal variability in moisture from MODIS NDVI data and thermal data. Discrepancies in the precipitation - vegetation relationship indicate areas with an alternative supply of water (i.e. not rainfall), this can be natural where moisture is supplied by upwelling groundwater, or can be artificial where crops are irrigated. As a result spatial and temporal variability in vegetation in the La Mancha Plain appears closely linked to topography, geology, rainfall and land use. Crop land shows large variability in year-to-year vegetation greenness; for some areas this variability is linked to variability in rainfall but in other cases this variability is linked to irrigation. The differences in irrigation treatment within one plant functional type, in this case crops, will lead to errors in land surface models when ignored. The magnitude of these effects on the energy, carbon and water balance are assessed at the scale of 250 m to 200 km. Estimating the water balance correctly is of particular important since in some areas in Spain more water is used for irrigation than is supplemented by rainfall.

  6. Prediction of Driver's Intention of Lane Change by Augmenting Sensor Information Using Machine Learning Techniques.

    Science.gov (United States)

    Kim, Il-Hwan; Bong, Jae-Hwan; Park, Jooyoung; Park, Shinsuk

    2017-06-10

    Driver assistance systems have become a major safety feature of modern passenger vehicles. The advanced driver assistance system (ADAS) is one of the active safety systems to improve the vehicle control performance and, thus, the safety of the driver and the passengers. To use the ADAS for lane change control, rapid and correct detection of the driver's intention is essential. This study proposes a novel preprocessing algorithm for the ADAS to improve the accuracy in classifying the driver's intention for lane change by augmenting basic measurements from conventional on-board sensors. The information on the vehicle states and the road surface condition is augmented by using an artificial neural network (ANN) models, and the augmented information is fed to a support vector machine (SVM) to detect the driver's intention with high accuracy. The feasibility of the developed algorithm was tested through driving simulator experiments. The results show that the classification accuracy for the driver's intention can be improved by providing an SVM model with sufficient driving information augmented by using ANN models of vehicle dynamics.

  7. Exploring drivers of wetland hydrologic fluxes across parameters and space

    Science.gov (United States)

    Jones, C. N.; Cheng, F. Y.; Mclaughlin, D. L.; Basu, N. B.; Lang, M.; Alexander, L. C.

    2017-12-01

    Depressional wetlands provide diverse ecosystem services, ranging from critical habitat to the regulation of landscape hydrology. The latter is of particular interest, because while hydrologic connectivity between depressional wetlands and downstream waters has been a focus of both scientific research and policy, it remains difficult to quantify the mode, magnitude, and timing of this connectivity at varying spatial and temporary scales. To do so requires robust empirical and modeling tools that accurately represent surface and subsurface flowpaths between depressional wetlands and other landscape elements. Here, we utilize a parsimonious wetland hydrology model to explore drivers of wetland water fluxes in different archetypal wetland-rich landscapes. We validated the model using instrumented sites from regions that span North America: Prairie Pothole Region (south-central Canada), Delmarva Peninsula (Mid-Atlantic Coastal Plain), and Big Cypress Swamp (southern Florida). Then, using several national scale datasets (e.g., National Wetlands Inventory, USFWS; National Hydrography Dataset, USGS; Soil Survey Geographic Database, NRCS), we conducted a global sensitivity analysis to elucidate dominant drivers of simulated fluxes. Finally, we simulated and compared wetland hydrology in five contrasting landscapes dominated by depressional wetlands: prairie potholes, Carolina and Delmarva bays, pocosins, western vernal pools, and Texas coastal prairie wetlands. Results highlight specific drivers that vary across these regions. Largely, hydroclimatic variables (e.g., PET/P ratios) controlled the timing and magnitude of wetland connectivity, whereas both wetland morphology (e.g., storage capacity and watershed size) and soil characteristics (e.g., ksat and confining layer depth) controlled the duration and mode (surface vs. subsurface) of wetland connectivity. Improved understanding of the drivers of wetland hydrologic connectivity supports enhanced, region

  8. Physics at an upgraded Fermilab proton driver

    Energy Technology Data Exchange (ETDEWEB)

    Geer, S.; /Fermilab

    2005-07-01

    In 2004 the Fermilab Long Range Planning Committee identified a new high intensity Proton Driver as an attractive option for the future, primarily motivated by the recent exciting developments in neutrino physics. Over the last few months a physics study has developed the physics case for the Fermilab Proton Driver. The potential physics opportunities are discussed.

  9. Functional Bus Driver-Pupil Passenger Relationships.

    Science.gov (United States)

    Farmer, Ernest

    1987-01-01

    Successful school bus drivers bring much more than mechanical know-how to the job. They develop good rapport with students while acting to bring undesirable student behavior under control. Drivers must also show an interest in students' welfare and have a good sense of humor. (MLH)

  10. Cedar Avenue driver assist system evaluation report.

    Science.gov (United States)

    2011-12-01

    This paper summarizes an evaluation of the Driver Assist System (DAS) used by the Minnesota Valley Transit Authority (MTVA) for bus shoulder operations. The DAS is a GPS-based technology suite that provides lane-position feedback to the driver via a ...

  11. Driver electronic device use in 2013.

    Science.gov (United States)

    2015-04-01

    The percentage of drivers text-messaging or visibly manipulating : hand-held devices increased from 1.5 percent in : 2012 to 1.7 percent in 2013; however, this was not a statistically : significant increase. Driver hand-held cell phone : use decrease...

  12. Vehicle and driver scheduling for public transit.

    Science.gov (United States)

    2009-08-01

    The problem of driver scheduling involves the construction of a legal set of shifts, including allowance : of overtime, which cover the blocks in a particular vehicle schedule. A shift is the work scheduled to be performed by : a driver in one day, w...

  13. Traffic Safety through Driver Assistance and Intelligence

    Directory of Open Access Journals (Sweden)

    Heiner Bubb

    2011-05-01

    BMW, Daimler, Audi, Citroen, Lexus, VW, Opel, Peugeot, Renault, Chevrolet, Saab and Bosch. Both the contributions of research work concerning driving behavior analysis and driver assistance systems have to be aligned with a permanently updated interaction within the system of driver, vehicle and road traffic environment.

  14. Impact Driver With Integral Sliding Hammer

    Science.gov (United States)

    Wallace, Bilby J.

    1987-01-01

    Tool combines impact driver with sliding dead-blow hammer. Used for any purpose for which ordinary impact driver used; tightening fasteners or driving starter holes for drill. Tool protects user from accidental injury and surrounding equipment from damage that might occur from ordinary arm-wielded hammer. Especially useful in underwater work.

  15. Driver citation/carrier data relationship project

    Science.gov (United States)

    1996-09-01

    The Driver/Carrier Relationship Project was commissioned to address three issues. The first was to determine if drivers of commercial motor vehicles get tickets at a different rate, depending on the carrier that they are working for. The second issue...

  16. About Assessment Criteria of Driver's Accidental Abilities

    Science.gov (United States)

    Lobanova, Yuliya I.; Glushko, Kirill V.

    2016-01-01

    The article points at the importance of studying the human factor as a cause of accidents of drivers, especially in loosely structured traffic situations. The description of the experiment on the measurement of driver's accidental abilities is given. Under accidental ability is meant the capability to ensure the security of driving as a behavior…

  17. Optimizing the Universal Robots ROS driver

    DEFF Research Database (Denmark)

    Andersen, Thomas Timm

    improvement both in terms of faster reaction as well as making it possible to control the robot using either ros_control or ordinary joint speed commands, which is required for many types of sensory based control like visual servoing. The developed driver is compared to the drivers already existing in the ROS...

  18. High speed CAMAC differential branch highway driver

    International Nuclear Information System (INIS)

    McMillan, D.E.; Nelson, R.O.; Poore, R.V.; Sunier, J.W.; Ross, J.J.

    1979-01-01

    A new CAMAC branch driver is described that incorporates several unusual features which combine to give reliable, high-speed performance. These include balanced line driver/receivers, stored CAMAC command lists, 8 DMA channels, pseudo LAMS, hardware priority encoding of LAMS, and hardware-implemented Q-controlled block transfers. 3 figures

  19. BDC 500 branch driver controller

    CERN Document Server

    Dijksman, A

    1981-01-01

    This processor has been designed for very fast data acquisition and date pre-processing. The dataway and branch highway speeds have been optimized for approximately 1.5 mu sec. The internal processor cycle is approximately 0.8 mu sec. The standard version contains the following functions (slots): crate controller type A1; branch highway driver including terminator; serial I/O port (TTY, VDU); 24 bit ALU and 24 bit program counter; 16 bit memory address counter and 4 word stack; 4k bit memory for program and/or data; battery backup for the memory; CNAFD and crate LAM display; request/grant logic for time- sharing operation of several BDCs. The free slots can be equipped with e.g. extra RAM, computer interfaces, hardware multiplier/dividers, etc. (0 refs).

  20. Visual behaviour analysis and driver cognitive model

    Energy Technology Data Exchange (ETDEWEB)

    Baujon, J.; Basset, M.; Gissinger, G.L. [Mulhouse Univ., (France). MIPS/MIAM Lab.

    2001-07-01

    Recent studies on driver behaviour have shown that perception - mainly visual but also proprioceptive perception - plays a key role in the ''driver-vehicle-road'' system and so considerably affects the driver's decision making. Within the framework of the behaviour analysis and studies low-cost system (BASIL), this paper presents a correlative, qualitative and quantitative study, comparing the information given by visual perception and by the trajectory followed. This information will help to obtain a cognitive model of the Rasmussen type according to different driver classes. Many experiments in real driving situations have been carried out for different driver classes and for a given trajectory profile, using a test vehicle and innovative, specially designed, real-time tools, such as the vision system or the positioning module. (orig.)

  1. SPIDER: A Framework for Understanding Driver Distraction.

    Science.gov (United States)

    Strayer, David L; Fisher, Donald L

    2016-02-01

    The objective was to identify key cognitive processes that are impaired when drivers divert attention from driving. Driver distraction is increasingly recognized as a significant source of injuries and fatalities on the roadway. A "SPIDER" model is developed that identifies key cognitive processes that are impaired when drivers divert attention from driving. SPIDER is an acronym standing for scanning, predicting, identifying, decision making, and executing a response. When drivers engage in secondary activities unrelated to the task of driving, SPIDER-related processes are impaired, situation awareness is degraded, and the ability to safely operate a motor vehicle may be compromised. The pattern of interference helps to illuminate the sources of driver distraction and may help guide the integration of new technology into the automobile. © 2015, Human Factors and Ergonomics Society.

  2. Modeling of Driver Steering Operations in Lateral Wind Disturbances toward Driver Assistance System

    Science.gov (United States)

    Kurata, Yoshinori; Wada, Takahiro; Kamiji, Norimasa; Doi, Shun'ichi

    Disturbances decrease vehicle stability and increase driver's mental and physical workload. Especially unexpected disturbances such as lateral winds have severe effect on vehicle stability and driver's workload. This study aims at building a driver model of steering operations in lateral wind toward developing effective driver assistance system. First, the relationship between the driver's lateral motion and its reactive quick steering behavior is investigated using driving simulator with lateral 1dof motion. In the experiments, four different wind patterns are displayed by the simulator. As the results, strong correlation was found between the driver's head lateral jerk by the lateral disturbance and the angular acceleration of the steering wheel. Then, we build a mathematical model of driver's steering model from lateral disturbance input to steering torque of the reactive quick feed-forward steering based on the experimental results. Finally, validity of the proposed model is shown by comparing the steering torque of experimental results and that of simulation results.

  3. Reducing risky driver behaviour through the implementation of a driver risk management system

    Directory of Open Access Journals (Sweden)

    Rose Luke

    2014-11-01

    Full Text Available South Africa has one of the highest incidences of road accidents in the world. Most accidents are avoidable and are caused by driver behaviour and errors. The purpose of this article was to identify the riskiest driver behaviours in commercial fleets in South Africa, to determine the business impact of such behaviour, to establish a framework for the management of risky driver behaviour and to test the framework by applying a leading commercial driver behaviour management system as a case study. The case study comprised three South African commercial fleets. Using data from these fleets, critical incident triangles were used to determine the ratio data of risky driver behaviour to near-collisions and collisions. Based on managing the riskiest driver behaviours as causes of more serious incidents and accidents, the results indicated that through the implementation of an effective driver risk management system, risky incidents were significantly reduced.

  4. Evolved osmotolerant Escherichia coli mutants frequently exhibit defective N-acetylglucosamine catabolism and point mutations in cell shape-regulating protein MreB.

    Science.gov (United States)

    Winkler, James D; Garcia, Carlos; Olson, Michelle; Callaway, Emily; Kao, Katy C

    2014-06-01

    Biocatalyst robustness toward stresses imposed during fermentation is important for efficient bio-based production. Osmotic stress, imposed by high osmolyte concentrations or dense populations, can significantly impact growth and productivity. In order to better understand the osmotic stress tolerance phenotype, we evolved sexual (capable of in situ DNA exchange) and asexual Escherichia coli strains under sodium chloride (NaCl) stress. All isolates had significantly improved growth under selection and could grow in up to 0.80 M (47 g/liter) NaCl, a concentration that completely inhibits the growth of the unevolved parental strains. Whole genome resequencing revealed frequent mutations in genes controlling N-acetylglucosamine catabolism (nagC, nagA), cell shape (mrdA, mreB), osmoprotectant uptake (proV), and motility (fimA). Possible epistatic interactions between nagC, nagA, fimA, and proV deletions were also detected when reconstructed as defined mutations. Biofilm formation under osmotic stress was found to be decreased in most mutant isolates, coupled with perturbations in indole secretion. Transcriptional analysis also revealed significant changes in ompACGL porin expression and increased transcription of sulfonate uptake systems in the evolved mutants. These findings expand our current knowledge of the osmotic stress phenotype and will be useful for the rational engineering of osmotic tolerance into industrial strains in the future. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

  5. Dancing on damaged chromatin. Functions of ATM and the RAD50/MRE11/NBS1 complex in cellular responses to DNA damage

    International Nuclear Information System (INIS)

    Iijima, Kenta; Ohara, Maki; Seki, Ryota; Tauchi, Hiroshi

    2008-01-01

    In order to preserve and protect genetic information, eukaryotic cells have developed a signaling or communications network to help the cell respond to DNA damage, and ATM and NBS1 are key players in this network. ATM is a protein kinase which is activated immediately after a DNA double strand break (DSB) is formed, and the resulting signal cascade generated in response to cellular DSBs is regulated by post-translational protein modifications such as phosphorylation and acetylation. In addition, to ensure the efficient functioning of DNA repair and cell cycle checkpoints, the highly ordered structure of eukaryotic chromatin must be appropriately altered to permit access of repair-related factors to DNA. These alterations are termed chromatin remodeling, and are executed by a specific remodeling complex in conjunction with histone modifications. Current advances in the molecular analysis of DNA damage responses have shown that the auto-phosphorylation of ATM and the interaction between ATM and NBS1 are key steps for ATM activation, and that the association of ATM and NBS1 is involved in chromatin remodeling. Identification of novel factors which function in ubiquitination (RNF8, Ubc13, Rap80, etc.) has also enabled us to understand more details of the early stages in DNA repair pathways which respond to DSBs. In this review, the focus is on the role of ATM and the RAD50/MRE11/NBS1 complex in DSB response pathways, and their role in DSB repair and in the regulation of chromatin remodeling. (author)

  6. How driving duration influences drivers' visual behaviors and fatigue ...

    African Journals Online (AJOL)

    unhcc

    Eye fixations express the focus of driver's visual attention on driving, ... driver's attention is attracted by fatigue. The second ... was divided into seven refined categories (see Table 1), ...... driver fatigue in terms of line crossing: a pilot study.

  7. Square pulse linear transformer driver

    Directory of Open Access Journals (Sweden)

    A. A. Kim

    2012-04-01

    Full Text Available The linear transformer driver (LTD technological approach can result in relatively compact devices that can deliver fast, high current, and high-voltage pulses straight out of the LTD cavity without any complicated pulse forming and pulse compression network. Through multistage inductively insulated voltage adders, the output pulse, increased in voltage amplitude, can be applied directly to the load. The usual LTD architecture [A. A. Kim, M. G. Mazarakis, V. A. Sinebryukhov, B. M. Kovalchuk, V. A. Vizir, S. N Volkov, F. Bayol, A. N. Bastrikov, V. G. Durakov, S. V. Frolov, V. M. Alexeenko, D. H. McDaniel, W. E. Fowler, K. LeCheen, C. Olson, W. A. Stygar, K. W. Struve, J. Porter, and R. M. Gilgenbach, Phys. Rev. ST Accel. Beams 12, 050402 (2009PRABFM1098-440210.1103/PhysRevSTAB.12.050402; M. G. Mazarakis, W. E. Fowler, A. A. Kim, V. A. Sinebryukhov, S. T. Rogowski, R. A. Sharpe, D. H. McDaniel, C. L. Olson, J. L. Porter, K. W. Struve, W. A. Stygar, and J. R. Woodworth, Phys. Rev. ST Accel. Beams 12, 050401 (2009PRABFM1098-440210.1103/PhysRevSTAB.12.050401] provides sine shaped output pulses that may not be well suited for some applications like z-pinch drivers, flash radiography, high power microwaves, etc. A more suitable power pulse would have a flat or trapezoidal (rising or falling top. In this paper, we present the design and first test results of an LTD cavity that generates such a type of output pulse by including within its circular array a number of third harmonic bricks in addition to the main bricks. A voltage adder made out of a square pulse cavity linear array will produce the same shape output pulses provided that the timing of each cavity is synchronized with the propagation of the electromagnetic pulse.

  8. Education for older drivers in the future

    Directory of Open Access Journals (Sweden)

    Esko Keskinen

    2014-07-01

    Five presumptions have to be considered when addressing future education for older drivers: 1. Driving a car will continue to be one element of mobility in the future; 2. Older people want to be able to keep driving; 3. Safety will be an even more important factor in mobility in the future; 4. Ecological values will be more important in the future; and 5. Innovative technological applications will be more important in the future. Hierarchical models of driving are suitable in increasing understanding of older drivers' needs and abilities. The highest levels of the driving hierarchy in the Goals for Driver Education (GDE model are especially important for the safety of both young and elderly drivers. In these highest levels goals for life, skills for living, and social environment affect everyday decision making in general but also driving, which has an impact on driver safety. Giving up driving is very much a social decision and should be taken as such. However, the highest levels of the driving hierarchy are by nature inaccessible to teacher-centered instruction These levels require more coaching-like education methods where the learner takes the central role and the teacher helps the drivers understand their own abilities and limitations in traffic. Testing and selecting older drivers to enhance safety is not, according to research findings, working in a proper way. Older drivers do not so much need more information concerning traffic rules, etc., but rather better understanding of themselves, their health restrictions, their skills, and their abilities to ensure daily mobility. Their closest companions also need tools to help them in discussions of traffic safety issues affecting older drivers.

  9. SUBJECTIVE METHODS FOR ASSESSMENT OF DRIVER DROWSINESS

    Directory of Open Access Journals (Sweden)

    Alina Mashko

    2017-12-01

    Full Text Available The paper deals with the issue of fatigue and sleepiness behind the wheel, which for a long time has been of vital importance for the research in the area of driver-car interaction safety. Numerous experiments on car simulators with diverse measurements to observe human behavior have been performed at the laboratories of the faculty of the authors. The paper provides analysis and an overview and assessment of the subjective (self-rating and observer rating methods for observation of driver behavior and the detection of critical behavior in sleep deprived drivers using the developed subjective rating scales.

  10. Will the Driver Seat Ever Be Empty?

    OpenAIRE

    Fraichard , Thierry

    2014-01-01

    Self-driving technologies have matured and improved to the point that, in the past few years, self-driving cars have been able to safely drive an impressive number of kilometers. It should be noted though that, in all cases, the driver seat was never empty: a human driver was behind the wheel, ready to take over whenever the situation dictated it. This is an interesting paradox since the point of a self-driving car is to remove the most unreliable part of the car, namely the human driver. So,...

  11. Tarantula: Killing driver bugs before they hatch

    DEFF Research Database (Denmark)

    Lawall, Julia Laetitia; Muller, Gilles; Urunuela, Richard

    2005-01-01

    The Linux operating system is undergoing continual evolution. Evolution in the kernel and generic driver modules often triggers the need for corresponding evolutions in specific device drivers. Such collateral evolutions are tedious, because of the large number of device drivers, and error......-prone, because of the complexity of the code modifications involved. We propose an automatic tool, Tarantula, to aid in this process. In this paper, we examine some recent evolutions in Linux and the collateral evolutions they trigger, and assess the corresponding requirements on Tarantula....

  12. Assessing the relationship between the Driver Behavior Questionnaire and the Driver Skill Inventory: Revealing sub-groups of drivers

    DEFF Research Database (Denmark)

    Martinussen, Laila Marianne; Møller, Mette; Prato, Carlo Giacomo

    2014-01-01

    The Driver Behavior Questionnaire and the Driver Skill Inventory are two of the most frequently used measures of self-reported driving style and driving skill. The motivation behind the present study was to identify sub-groups of drivers that potentially act dangerously in traffic (as measured...... self-reported driving skills and whether the reported skill level was reflected in the reported aberrant driving behaviors. 3908 drivers aged 18–84 participated in the survey. K-means cluster analysis revealed four distinct sub-groups that differed in driving skills and frequency of aberrant driving...... by frequency of aberrant driving behaviors and level of driving skills), as well as to test whether the sub-groups differ in characteristics such as age, gender, annual mileage and accident involvement. Furthermore, the joint analysis of the two instruments was used to test drivers’ assessment of their own...

  13. 2010 driver attitudes and awareness survey.

    Science.gov (United States)

    2010-08-01

    A basic of questions were developed that could be used in periodic surveys that track drivers attitudes and awareness concerning impaired driving, seat belt use, and speeding issues. The objective of the survey was to learn the knowledge, views, and ...

  14. Understanding & modeling bus transit driver availability.

    Science.gov (United States)

    2014-07-01

    Bus transit agencies are required to hire extraboard (i.e. back-up) operators to account for unexpected absences. Incorrect sizing of extra driver workforce is problematic for a number of reasons. Overestimating the appropriate number of extraboard o...

  15. Chinese Road Safety and Driver Behavior Research

    OpenAIRE

    Wang, Junhua

    2015-01-01

    The seminar will begin with a brief overview of the Chinese road safety situation, including current safety problems, and then move on to discuss safety research including driver behavior, freeway operational safety, and infrastructure development.

  16. Drug involvement of fatally injured drivers

    Science.gov (United States)

    2010-11-01

    While data focusing on the danger of driving under the influence : of alcohol is readily available and often cited, less is : known or discussed about drivers under the influence of : other drugs. The Fatality Analysis Reporting System (FARS), : a ce...

  17. Driver Education for New Multimodal Facilities

    Science.gov (United States)

    2016-05-24

    Local and state transportation agencies are redesigning roads to accommodate multimodal travel, including the addition of new configurations, infrastructures, and rules that may be unfamiliar to current drivers and other road users. Education and out...

  18. Deregulation and Macroeconomic Drivers Of Foreign Direct ...

    African Journals Online (AJOL)

    Deregulation and Macroeconomic Drivers Of Foreign Direct Investment In Nigerian Agriculture (1970 -2009): An Econometric Analysis. ... The study showed that foreign exchange and the economic deregulation policy of Nigerian government ...

  19. Symbol signing design for older drivers

    Science.gov (United States)

    1997-07-01

    This project evaluated the effectiveness of symbol traffic signs for young, middle-aged and elderly drivers. Daytime legibility distance and comprehension of 85 symbols in the Manual on Uniform Traffic Control Devices (MUTCD) were measured. Legibilit...

  20. Teen driver crashes : a report to Congress

    Science.gov (United States)

    2008-07-01

    This report summarizes what is known about the teen driver crash problem and reviews the research on the major contributing factors to the high teen crash rate. Dispositional factors, such as immaturity, inexperience, faulty judgment, and a higher pr...

  1. The importance of sight for drivers

    Directory of Open Access Journals (Sweden)

    Alicja Pas-Wyroślak

    2013-06-01

    Full Text Available Sight is the basic sense for drivers. Condition of the eye determines correct, comfortable and safe performance of the work as drivers. This article presents various factors influencing the sight condition. There are two groups of factors, external (environment, the kind and time of work, stress caused by work and internal (systemic and local disorders. All these factors can reduce significantly visual functions, such as visual acuity, field of vision, color vision, strereoscopic vision, twilight vision and glare sensitivity. There are also presented actual requirements for drivers and causes of the car accidents in various age groups. Impairments in vision functions can be dangerous for both the driver and other road users. Med Pr 2013;64(3:419–425

  2. Experimental testing of designated driver cues

    Science.gov (United States)

    2000-07-27

    In theory, the designated-driver concept holds great promise for reducing the incidences of drunk driving. It is simple, inexpensive, almost universally recognized, and generally positively regarded by the U.S. population as a means for avoiding drun...

  3. Heavy-ion driver parametric studies and choice of a base 5 mega-joule driver design

    International Nuclear Information System (INIS)

    Bieri, R.; Meier, W.

    1992-01-01

    Parametric studies to optimize heavy-ion driver designs are described and an optimized 5 MJ driver design is described. Parametric studies are done on driver parameters including driver energy, number of beams, type of superconductor used in focusing magnets, maximum magnetic field allowed at the superconducting windings, axial quadrupole field packing fraction, ion mass, and ion charge state. All modeled drivers use the maximum beam currents allowed by the Maschke limits; driver scaling is described in a companion paper. The optimized driver described is conservative and cost effective. The base driver direct costs are only $120/Joule, and the base driver uses no recirculation, beam combination, or beam separation. The low driver cost achieved is due, in part, to the use of compact Nb 3 Sn quadrupole arrays, but results primarily from optimization over the large, multi-dimensional, parameter space available for heavy-ion drivers

  4. A study of at-fault older drivers in light-vehicle crashes in Singapore.

    Science.gov (United States)

    Chin, Hoong Chor; Zhou, Mo

    2018-03-01

    A number of studies on motor vehicle crashes have suggested that older drivers are more likely to be at-fault compared to younger drivers. The objective of this paper is to identify factors that contribute to older drivers (aged 65 and above) being at fault in light vehicle crashes in Singapore. Based on 3 years of crash data, the calibrated binary logit model shows that older drivers are more likely to be at fault during peak periods and festive seasons between November to February, as well as at gore areas of expressways, intersections. Curb lanes of multi-lane roads and single-lane roads are also found to increase the odds of older drivers being at fault. Furthermore, older drivers appear to have more problems on roads with wet surfaces and speed limits of 60 km/h and 70 km/h. In the light of an aging population in Singapore, it is imperative that more targeted countermeasures be taken from multiple perspectives to lower such risks. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Identification of drivers for modular production

    DEFF Research Database (Denmark)

    Brunoe, Thomas Ditlev; Bossen, Jacob; Nielsen, Kjeld

    2015-01-01

    Todays competitive environment in industry creates a need for companies to enhance their ability to introduce new products faster. To increase rampup speed reconfigurable manufacturing systems is a promising concept, however to implement this production platforms and modular manufacturing...... is required. This paper presents an analysis whether and which module drivers from general product development can be applied to the development process of a modular manufacturing system. The result is a compiled list of modular drivers for manufacturing and examples of their use....

  6. Important information for drivers in France

    CERN Multimedia

    2012-01-01

    From 1 July 2012, any driver of a motorised road vehicle, excluding two- or three-wheeled vehicles whose engine capacity does not exceed 50cm3, must be in possession of a breathalyser in full working order. With effect from 1 November 2012*, drivers failing to produce a breathalyser run the risk of being served with an 11 euro fine. A breathalyser is used to measure the alcohol content in the motorist's breath. The permissible level of alcohol for drivers is less than 0.5 g of alcohol per litre of blood, or 0.25 mg of alcohol per litre of air exhaled. The obligation to have a breathalyser on board the vehicle also applies to all drivers on the French part of the CERN site. All vehicles belonging to or leased by the Organization must also carry a breathalyser together with all the requisite documentation (cf. Operational Circular No. 4). Drivers of privately owned vehicles can obtain breathalysers from car accessory dealers, service stations or pharmacies, etc. Drivers of vehicles belonging to or l...

  7. Myocardial infarction in Swedish subway drivers.

    Science.gov (United States)

    Bigert, Carolina; Klerdal, Kristina; Hammar, Niklas; Gustavsson, Per

    2007-08-01

    Particulate matter in urban air is associated with the risk of myocardial infarction in the general population. Very high levels of airborne particles have been detected in the subway system of Stockholm, as well as in several other large cities. This situation has caused concern for negative health effects among subway staff. The aim of this study was to investigate whether there is an increased incidence of myocardial infarction among subway drivers. Data from a population-based case-control study of men aged 40-69 in Stockholm County in 1976-1996 were used. The study included all first events of myocardial infarction in registers of hospital discharges and deaths. The controls were selected randomly from the general population. National censuses were used for information on occupation. Altogether, 22 311 cases and 131 496 controls were included. Among these, 54 cases and 250 controls had worked as subway drivers. The relative risk of myocardial infarction among subway drivers was not increased. It was 0.92 [95% confidence interval (95% CI) 0.68-1.25] when the subway drivers were compared with other manual workers and 1.06 (95% CI 0.78-1.43) when the subway drivers were compared with all other gainfully employed men. Subgroup analyses indicated no influence on the risk of myocardial infarction from the duration of employment, latency time, or time since employment stopped. Subway drivers in Stockholm do not have a higher incidence of myocardial infarction than other employed persons.

  8. Effects of Defensive Vehicle Handling on Novice Driver Safety : Phase 3. Data Analysis and Results

    Science.gov (United States)

    2010-09-01

    This project evaluates the effectiveness of a multistage driver education program for Montanas young : drivers. A total of 347 teenaged drivers who had completed high school driver education agreed to participate. : These drivers were randomly spl...

  9. Workshop on transport for a common ion driver

    International Nuclear Information System (INIS)

    Olson, C.C.; Lee, E.; Langdon, B.

    1994-01-01

    This report contains research in the following areas related to beam transport for a common ion driver: multi-gap acceleration; neutralization with electrons; gas neutralization; self-pinched transport; HIF and LIF transport, and relevance to common ion driver; LIF and HIF reactor concepts and relevance to common ion driver; atomic physics for common ion driver; code capabilities and needed improvement

  10. Conceptual Drivers for an Exploration Medical System

    Science.gov (United States)

    Antonsen, Erik; Hanson, Andrea; Shah, Ronak; Reed, Rebekah; Canga, Michael

    2016-01-01

    Interplanetary spaceflight, such as NASA's proposed three-year mission to Mars, provides unique and novel challenges when compared with human spaceflight to date. Extended distance and multi-year missions introduce new elements of operational complexity and additional risk. These elements include: inability to resupply medications and consumables, inability to evacuate injured or ill crew, uncharted psychosocial conditions, and communication delays that create a requirement for some level of autonomous medical capability. Because of these unique challenges, the approaches used in prior programs have limited application to a Mars mission. On a Mars mission, resource limitations will significantly constrain available medical capabilities, and require a paradigm shift in the approach to medical system design and risk mitigation for crew health. To respond to this need for a new paradigm, the Exploration Medical Capability (ExMC) Element is assessing each Mars mission phase-transit, surface stay, rendezvous, extravehicular activity, and return-to identify and prioritize medical needs for the journey beyond low Earth orbit (LEO). ExMC is addressing both planned medical operations, and unplanned contingency medical operations that meld clinical needs and research needs into a single system. This assessment is being used to derive a gap analysis and studies to support meaningful medical capabilities trades. These trades, in turn, allow the exploration medical system design to proceed from both a mission centric and ethics-based approach, and to manage the risks associated with the medical limitations inherent in an exploration class mission. This paper outlines the conceptual drivers used to derive medical system and vehicle needs from an integrated vision of how medical care will be provided within this paradigm. Keywords: (Max 6 keywords: exploration, medicine, spaceflight, Mars, research, NASA)

  11. Reliability of drivers in urban intersections.

    Science.gov (United States)

    Gstalter, Herbert; Fastenmeier, Wolfgang

    2010-01-01

    The concept of human reliability has been widely used in industrial settings by human factors experts to optimise the person-task fit. Reliability is estimated by the probability that a task will successfully be completed by personnel in a given stage of system operation. Human Reliability Analysis (HRA) is a technique used to calculate human error probabilities as the ratio of errors committed to the number of opportunities for that error. To transfer this notion to the measurement of car driver reliability the following components are necessary: a taxonomy of driving tasks, a definition of correct behaviour in each of these tasks, a list of errors as deviations from the correct actions and an adequate observation method to register errors and opportunities for these errors. Use of the SAFE-task analysis procedure recently made it possible to derive driver errors directly from the normative analysis of behavioural requirements. Driver reliability estimates could be used to compare groups of tasks (e.g. different types of intersections with their respective regulations) as well as groups of drivers' or individual drivers' aptitudes. This approach was tested in a field study with 62 drivers of different age groups. The subjects drove an instrumented car and had to complete an urban test route, the main features of which were 18 intersections representing six different driving tasks. The subjects were accompanied by two trained observers who recorded driver errors using standardized observation sheets. Results indicate that error indices often vary between both the age group of drivers and the type of driving task. The highest error indices occurred in the non-signalised intersection tasks and the roundabout, which exactly equals the corresponding ratings of task complexity from the SAFE analysis. A comparison of age groups clearly shows the disadvantage of older drivers, whose error indices in nearly all tasks are significantly higher than those of the other groups

  12. Assessing drivers' response during automated driver support system failures with non-driving tasks.

    Science.gov (United States)

    Shen, Sijun; Neyens, David M

    2017-06-01

    With the increase in automated driver support systems, drivers are shifting from operating their vehicles to supervising their automation. As a result, it is important to understand how drivers interact with these automated systems and evaluate their effect on driver responses to safety critical events. This study aimed to identify how drivers responded when experiencing a safety critical event in automated vehicles while also engaged in non-driving tasks. In total 48 participants were included in this driving simulator study with two levels of automated driving: (a) driving with no automation and (b) driving with adaptive cruise control (ACC) and lane keeping (LK) systems engaged; and also two levels of a non-driving task (a) watching a movie or (b) no non-driving task. In addition to driving performance measures, non-driving task performance and the mean glance duration for the non-driving task were compared between the two levels of automated driving. Drivers using the automated systems responded worse than those manually driving in terms of reaction time, lane departure duration, and maximum steering wheel angle to an induced lane departure event. These results also found that non-driving tasks further impaired driver responses to a safety critical event in the automated system condition. In the automated driving condition, driver responses to the safety critical events were slower, especially when engaged in a non-driving task. Traditional driver performance variables may not necessarily effectively and accurately evaluate driver responses to events when supervising autonomous vehicle systems. Thus, it is important to develop and use appropriate variables to quantify drivers' performance under these conditions. Copyright © 2017 Elsevier Ltd and National Safety Council. All rights reserved.

  13. Climate drivers of regionally synchronous fires in the inland northwest (1651-1900)

    Science.gov (United States)

    Emily K. Heyerdahl; Donald McKenzie; Lori D. Daniels; Amy E. Hessl; Jeremy S. Littell; Nathan J. Mantua

    2008-01-01

    We inferred climate drivers of regionally synchronous surface fires from 1651 to 1900 at 15 sites with existing annually accurate fire-scar chronologies from forests dominated by ponderosa pine or Douglas-fir in the inland Northwest (interior Oregon,Washington and southern British Columbia).Years with widespread fires (35 years with fire at 7 to 11 sites) had warm...

  14. Hydrochloric acid: an overlooked driver of environmental change.

    Science.gov (United States)

    Evans, Chris D; Monteith, Don T; Fowler, David; Cape, J Neil; Brayshaw, Susan

    2011-03-01

    Research on the ecosystem impacts of acidifying pollutants, and measures to control them, has focused almost exclusively on sulfur (S) and nitrogen (N) compounds. Hydrochloric acid (HCl), although emitted by coal burning, has been overlooked as a driver of ecosystem change because most of it was considered to redeposit close to emission sources rather than in remote natural ecosystems. Despite receiving little regulatory attention, measures to reduce S emissions, and changes in energy supply, have led to a 95% reduction in United Kingdom HCl emissions within 20 years. Long-term precipitation, surface water, and soil solution data suggest that the near-disappearance of HCl from deposition could account for 30-40% of chemical recovery from acidification during this time, affecting both near-source and remote areas. Because HCl is highly mobile in reducing environments, it is a more potent acidifier of wetlands than S or N, and HCl may have been the major driver of past peatland acidification. Reduced HCl loadings could therefore have affected the peatland carbon cycle, contributing to increases in dissolved organic carbon leaching to surface waters. With many regions increasingly reliant on coal for power generation, HCl should be recognized as a potentially significant constituent of resulting emissions, with distinctive ecosystem impacts.

  15. Novice drivers' individual trajectories of driver behavior over the first three years of driving.

    Science.gov (United States)

    Roman, Gabriela D; Poulter, Damian; Barker, Edward; McKenna, Frank P; Rowe, Richard

    2015-09-01

    Identifying the changes in driving behavior that underlie the decrease in crash risk over the first few months of driving is key to efforts to reduce injury and fatality risk in novice drivers. This study represented a secondary data analysis of 1148 drivers who participated in the UK Cohort II study. The Driver Behavior Questionnaire was completed at 6 months and 1, 2 and 3 years after licensure. Linear latent growth models indicated significant increases across development in all four dimensions of aberrant driving behavior under scrutiny: aggressive violations, ordinary violations, errors and slips. Unconditional and conditional latent growth class analyses showed that the observed heterogeneity in individual trajectories was explained by the presence of multiple homogeneous groups of drivers, each exhibiting specific trajectories of aberrant driver behavior. Initial levels of aberrant driver behavior were important in identifying sub-groups of drivers. All classes showed positive slopes; there was no evidence of a group of drivers whose aberrant behavior decreased over time that might explain the decrease in crash involvement observed over this period. Male gender and younger age predicted membership of trajectories with higher levels of aberrant behavior. These findings highlight the importance of early intervention for improving road safety. We discuss the implications of our findings for understanding the behavioral underpinnings of the decrease in crash involvement observed in the early months of driving. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Assisting Driver Sovereignty : A Fail-Safe Design Approach to Driver Distraction

    NARCIS (Netherlands)

    Van Gijssel, A.

    2013-01-01

    This thesis investigates the potential of a fail-safe approach to driver distraction through novel interface concepts for integrated Advanced Driver Assistance Systems (ADAS). Traffic accidents are a negative side effect of the universal and economical desire for mobility. The year 2009 saw the

  17. Redesign of Transjakarta Bus Driver's Cabin

    Science.gov (United States)

    Mardi Safitri, Dian; Azmi, Nora; Singh, Gurbinder; Astuti, Pudji

    2016-02-01

    Ergonomic risk at work stations with type Seated Work Control was one of the problems faced by Transjakarta bus driver. Currently “Trisakti” type bus, one type of bus that is used by Transjakarta in corridor 9, serving route Pinang Ranti - Pluit, gained many complaints from drivers. From the results of Nordic Body Map questionnaires given to 30 drivers, it was known that drivers feel pain in the neck, arms, hips, and buttocks. Allegedly this was due to the seat position and the button/panel bus has a considerable distance range (1 meter) to be achieved by drivers. In addition, preliminary results of the questionnaire using Workstation Checklist identified their complaints about uncomfortable cushion, driver's seat backrest, and the exact position of the AC is above the driver head. To reduce the risk level of ergonomics, then did research to design the cabin by using a generic approach to designing products. The risk analysis driver posture before the design was done by using Rapid Upper Limb Assessment (RULA), Rapid Entire Body Assessment (REBA), and Quick Exposure Checklist (QEC), while the calculation of the moment the body is done by using software Mannequin Pro V10.2. Furthermore, the design of generic products was done through the stages: need metric-matrix, house of quality, anthropometric data collection, classification tree concept, concept screening, scoring concept, design and manufacture of products in the form of two-dimensional. While the design after design risk analysis driver posture was done by using RULA, REBA, and calculation of moments body as well as the design visualized using software 3DMax. From the results of analysis before the draft design improvements cabin RULA obtained scores of 6, REBA 9, and the result amounted to 57.38% QEC and moment forces on the back is 247.3 LbF.inch and on the right hip is 72.9 LbF.in. While the results of the proposed improvements cabin design RULA obtained scores of 3, REBA 4, and the moment of force on

  18. Driver's Behavior Modeling Using Fuzzy Logic

    Directory of Open Access Journals (Sweden)

    Sehraneh Ghaemi

    2010-01-01

    Full Text Available In this study, we propose a hierarchical fuzzy system for human in a driver-vehicle-environment system to model takeover by different drivers. The driver's behavior is affected by the environment. The climate, road and car conditions are included in fuzzy modeling. For obtaining fuzzy rules, experts' opinions are benefited by means of questionnaires on effects of parameters such as climate, road and car conditions on driving capabilities. Also the precision, age and driving individuality are used to model the driver's behavior. Three different positions are considered for driving and decision making. A fuzzy model called Model I is presented for modeling the change of steering angle and speed control by considering time distances with existing cars in these three positions, the information about the speed and direction of car, and the steering angle of car. Also we obtained two other models based on fuzzy rules called Model II and Model III by using Sugeno fuzzy inference. Model II and Model III have less linguistic terms than Model I for the steering angle and direction of car. The results of three models are compared for a driver who drives based on driving laws.

  19. Views of US drivers about driving safety.

    Science.gov (United States)

    Williams, Allan F

    2003-01-01

    To assess how drivers view dangers on the highway, what motivates them to drive safely, how they say they reduce their crash and injury risk, and how they rate their own driving skills. Most drivers rated their skills as better than average. The biggest motivating factor for safe driving was concern for safety of others in their vehicle, followed by negative outcomes such as being in a crash, increased insurance costs, and fines. The greatest threats to their safety were thought to be other drivers' actions that increase crash risk such as alcohol impairment or running red lights. In terms of reducing crashes and injuries, drivers tended to focus on actions they could take such as driving defensively or using seat belts. There was less recognition of the role of vehicles and vehicle features in crash or injury prevention. Knowing how drivers view themselves and others, their concerns, and their motivations and techniques for staying out of trouble on the roads provides insight into the difficulty of changing driving practices.

  20. Railway suicide: the psychological effects on drivers.

    Science.gov (United States)

    Farmer, R; Tranah, T; O'Donnell, I; Catalan, J

    1992-05-01

    People have jumped (or fallen) in front of trains on the London Underground system in increasing numbers throughout the twentieth century. During the past decade there have been about 100 such incidents each year, of which around 90 would involve the train driver witnessing his train strike the person on the track. Most are suicides or attempts at suicide. They represent major unexpected and violent events in the lives of the train drivers and it might be expected that some of them would respond by developing a post-traumatic stress reaction of the type identified by Horowitz (1976) or other adverse psychological reactions or both. The research reported in this paper was designed to characterize the range of responses of drivers to the experiences of killing or injuring members of the public during the course of their daily work. It was found that 16.3% of the drivers involved in incidents did develop post-traumatic stress disorder and that other diagnoses, e.g. depression and phobic states, were present in 39.5% of drivers when interviewed one month after the incident.

  1. Determinants and Drivers of Infectious Disease Threat Events in Europe.

    Science.gov (United States)

    Semenza, Jan C; Lindgren, Elisabet; Balkanyi, Laszlo; Espinosa, Laura; Almqvist, My S; Penttinen, Pasi; Rocklöv, Joacim

    2016-04-01

    Infectious disease threat events (IDTEs) are increasing in frequency worldwide. We analyzed underlying drivers of 116 IDTEs detected in Europe during 2008-2013 by epidemic intelligence at the European Centre of Disease Prevention and Control. Seventeen drivers were identified and categorized into 3 groups: globalization and environment, sociodemographic, and public health systems. A combination of >2 drivers was responsible for most IDTEs. The driver category globalization and environment contributed to 61% of individual IDTEs, and the top 5 individual drivers of all IDTEs were travel and tourism, food and water quality, natural environment, global trade, and climate. Hierarchical cluster analysis of all drivers identified travel and tourism as a distinctly separate driver. Monitoring and modeling such disease drivers can help anticipate future IDTEs and strengthen control measures. More important, intervening directly on these underlying drivers can diminish the likelihood of the occurrence of an IDTE and reduce the associated human and economic costs.

  2. A novel membrane-bound toxin for cell division, CptA (YgfX), inhibits polymerization of cytoskeleton proteins, FtsZ and MreB, in Escherichia coli.

    Science.gov (United States)

    Masuda, Hisako; Tan, Qian; Awano, Naoki; Yamaguchi, Yoshihiro; Inouye, Masayori

    2012-03-01

    Nearly all free-living bacteria carry toxin-antitoxin (TA) systems on their genomes, through which cell growth and death are regulated. Toxins target a variety of essential cellular functions, including DNA replication, translation, and cell division. Here, we identified a novel toxin, YgfX, on the Escherichia coli genome. The toxin, consisting of 135 residues, is composed of the N-terminal membrane domain, which encompasses two transmembrane segments, and the C-terminal cytoplasmic domain. Upon YgfX expression, the cells were initially elongated and then the middle portion of the cells became inflated to form a lemon shape. YgfX was found to interact with MreB and FtsZ, two essential cytoskeletal proteins in E. coli. The cytoplasmic domain [YgfX(C)] was found to be responsible for the YgfX toxicity, as purified YgfX(C) was found to block the polymerization of FtsZ and MreB in vitro. YgfY, located immediately upstream of YgfX, was shown to be the cognate antitoxin; notably, YgfX is the first membrane-associating toxin in bacterial TA systems. We propose to rename the toxin and the antitoxin as CptA and CptB (for Cytoskeleton Polymerization inhibiting Toxin), respectively. © 2012 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.

  3. Classifying Drivers' Cognitive Load Using EEG Signals.

    Science.gov (United States)

    Barua, Shaibal; Ahmed, Mobyen Uddin; Begum, Shahina

    2017-01-01

    A growing traffic safety issue is the effect of cognitive loading activities on traffic safety and driving performance. To monitor drivers' mental state, understanding cognitive load is important since while driving, performing cognitively loading secondary tasks, for example talking on the phone, can affect the performance in the primary task, i.e. driving. Electroencephalography (EEG) is one of the reliable measures of cognitive load that can detect the changes in instantaneous load and effect of cognitively loading secondary task. In this driving simulator study, 1-back task is carried out while the driver performs three different simulated driving scenarios. This paper presents an EEG based approach to classify a drivers' level of cognitive load using Case-Based Reasoning (CBR). The results show that for each individual scenario as well as using data combined from the different scenarios, CBR based system achieved approximately over 70% of classification accuracy.

  4. Linear transformer driver for pulse generation

    Science.gov (United States)

    Kim, Alexander A; Mazarakis, Michael G; Sinebryukhov, Vadim A; Volkov, Sergey N; Kondratiev, Sergey S; Alexeenko, Vitaly M; Bayol, Frederic; Demol, Gauthier; Stygar, William A

    2015-04-07

    A linear transformer driver includes at least one ferrite ring positioned to accept a load. The linear transformer driver also includes a first power delivery module that includes a first charge storage devices and a first switch. The first power delivery module sends a first energy in the form of a first pulse to the load. The linear transformer driver also includes a second power delivery module including a second charge storage device and a second switch. The second power delivery module sends a second energy in the form of a second pulse to the load. The second pulse has a frequency that is approximately three times the frequency of the first pulse. The at least one ferrite ring is positioned to force the first pulse and the second pulse to the load by temporarily isolating the first pulse and the second pulse from an electrical ground.

  5. Drivers and moderators of business decline

    Directory of Open Access Journals (Sweden)

    Marius Pretorius

    2010-12-01

    Full Text Available Purpose: Reports of business failure elicit various reactions, while research in this domain often appears to be limited by a lack of access to information about failure and by the negativity that surrounds it. Those who have experienced failure do not readily talk about it, or they disappear from the radar screen of researchers. Yet failure is preceded by decline which, when focused on strategically, can reduce eventual failures if early action is taken. The main purpose of this study is to develop a conceptual framework or typology of the drivers and moderators of business decline. Design/methodology/approach: After applying the "grounded theory" approach to the academic literature on decline and failure, a conceptual framework for the variables that drive and moderate business decline is proposed. Findings: The study proposes that decline has three core drivers, three peripheral drivers and four moderators. The core drivers identified are: resource munificence; leadership as origin; and causality (strategic versus operational origin of decline. The three peripheral drivers are: unique preconditions; continuous decisions impact; and extremes dichotomy. The study describes four moderators of the drivers: life cycle stage; stakeholder perspective; quantitative versus qualitative nature of signs and causes; and finally the age and size effects. Research limitations/implications: The proposed conceptual framework is based on literature only, although it has found support during discussions with practitioners. It is proposed to readers of this journal for scrutiny and validation. Practical implications: Strategists need to understand what drives decline in order to act timeously; practitioners who have an insight into the moderators with their impacts could make better decisions in response to decline in organisations and possibly avoid business failure. Originality/Value: Understanding business decline is still a huge theoretical challenge, which

  6. [Occupational stress situation analysis of different types of train drivers].

    Science.gov (United States)

    Zhou, Wenhui; Gu, Guizhen; Wu, Hui; Yu, Shanfa

    2014-11-01

    To analyze the status of occupational stress in different types of train drivers. By using cluster sampling method, a cross-sectional study was conducted in 1 339 train drivers (including 289 passenger train drivers, 637 freight trains drivers, 339 passenger shunting train drivers, and 74 high speed rail drivers) from a Railway Bureau depot. The survey included individual factors, occupational stress factors, stress response factors and stress mitigating factors. The occupational stress factors, stress response factors and mitigating factors were measured by the revised effort-reward imbalance (ERI) model questionnaires and occupational stress measurement scale. By using the method of covariance analysized the difference of occupational stress factors of all types train drivers, the method of Stepwise regression was used to analyze the effection (R(2)) of occupational stress factors and stress mitigating factors on stress response factors. Covariance analysis as covariates in age, education level, length of service and marital status showed that the scores of ERI (1.58 ± 0.05), extrinsic effort (19.88 ± 0.44), rewards (23.43 ± 0.43), intrinsic effort (17.86 ± 0.36), physical environment (5.70 ± 0.22), social support (30.51 ± 0.88) and daily tension (10.27 ± 0.38 ) of high speed rail drivers were higher than other drivers (F values were 6.06, 11.32, 7.05, 13.25, 5.20, 9.48 and 6.14 respectively, P occupational stress factors and mitigating factors to depressive symptoms of train drivers was high speed rail drivers (R(2) = 0.64), passenger train drivers (R(2) = 0.44), passenger shunting train drivers (R(2) = 0.39), freight trains drivers (R(2) = 0.38); job satisfaction of train drivers was high speed rail drivers (R(2) = 0.68), passenger train drivers (R(2) = 0.62), freight trains drivers (R(2) = 0.43), passenger shunting train drivers(R(2) = 0.38); to daily tension of train drivers was high speed rail drivers (R(2) = 0.54), passenger train drivers (R(2) = 0

  7. Physics at a New Fermilab Proton Driver

    International Nuclear Information System (INIS)

    Geer, Steve

    2005-01-01

    In 2004 the Fermilab Long Range Planning Committee identified a new high intensity Proton Driver as an attractive option for the future, primarily motivated by the recent exciting developments in neutrino physics. The Fermilab Director has requested further development of the physics case for a new Fermilab Proton Driver, exploring both its ability to support a World class neutrino program, and the other physics opportunities it would provide. A physics study has been ongoing for the last 6 months. The emerging physics case will be presented.

  8. Understanding Collateral Evolution in Linux Device Drivers

    DEFF Research Database (Denmark)

    Padioleau, Yoann; Lawall, Julia Laetitia; Muller, Gilles

    2006-01-01

    no tools to help in this process, collateral evolution is thus time consuming and error prone.In this paper, we present a qualitative and quantitative assessment of collateral evolution in Linux device driver code. We provide a taxonomy of evolutions and collateral evolutions, and use an automated patch......-analysis tool that we have developed to measure the number of evolutions and collateral evolutions that affect device drivers between Linux versions 2.2 and 2.6. In particular, we find that from one version of Linux to the next, collateral evolutions can account for up to 35% of the lines modified in such code....

  9. Kin-Driver: a database of driver mutations in protein kinases.

    Science.gov (United States)

    Simonetti, Franco L; Tornador, Cristian; Nabau-Moretó, Nuria; Molina-Vila, Miguel A; Marino-Buslje, Cristina

    2014-01-01

    Somatic mutations in protein kinases (PKs) are frequent driver events in many human tumors, while germ-line mutations are associated with hereditary diseases. Here we present Kin-driver, the first database that compiles driver mutations in PKs with experimental evidence demonstrating their functional role. Kin-driver is a manual expert-curated database that pays special attention to activating mutations (AMs) and can serve as a validation set to develop new generation tools focused on the prediction of gain-of-function driver mutations. It also offers an easy and intuitive environment to facilitate the visualization and analysis of mutations in PKs. Because all mutations are mapped onto a multiple sequence alignment, analogue positions between kinases can be identified and tentative new mutations can be proposed for studying by transferring annotation. Finally, our database can also be of use to clinical and translational laboratories, helping them to identify uncommon AMs that can correlate with response to new antitumor drugs. The website was developed using PHP and JavaScript, which are supported by all major browsers; the database was built using MySQL server. Kin-driver is available at: http://kin-driver.leloir.org.ar/ © The Author(s) 2014. Published by Oxford University Press.

  10. An application of the driver behavior questionnaire to Chinese carless young drivers.

    Science.gov (United States)

    Zhang, Qian; Jiang, Zuhua; Zheng, Dongpeng; Wang, Yifan; Man, Dong

    2013-01-01

    Carless young drivers refers to those drivers aged between 18 and 25 years who have a driver's license but seldom have opportunities to practice their driving skills because they do not have their own cars. Due to China's lower private car ownership, many young drivers turn into carless young drivers after licensure, and the safety issue associated with them has become a matter of great concern in China. Because few studies have examined the driving behaviors of these drivers, this study aims to utilize the Driver Behavior Questionnaire (DBQ) to investigate the self-reported driving behaviors of Chinese carless young drivers. A total of 523 Chinese carless young drivers (214 females, 309 males) with an average age of 21.91 years completed a questionnaire including the 27-item DBQ and demographics. The data were first randomized into 2 subsamples for factor analysis and then combined together for the following analyses. Both an exploratory factor analysis (EFA, n = 174) and a confirmatory factor analysis (CFA, n = 349) were performed to investigate the factor structure of the DBQ. Correlation analysis was conducted to examine the relationships between the demographics and the DBQ scales' variables. Multivariate linear regression and logistic regression were performed to investigate the prediction of the DBQ scales and crash involvement in the previous year. The EFA produced a 4-factor structure identified as errors, violations, attention lapses, and memory lapses, and the CFA revealed a good model fit after the removal of one item with a low factor loading and the permission of the error covariance between some items. The Chinese carless young drivers reported a comparatively low level of aberrant driving behaviors. The 3 most frequently reported behaviors were all lapses and the 3 least were all violations. Gender was the only significant predictor of the 2 lapses scales and lifetime mileage was the only significant predictor of the violations scale. Only the

  11. Levitation With a Single Acoustic Driver

    Science.gov (United States)

    Barmatz, M. B.; Gaspar, M. S.; Allen, J. L.

    1986-01-01

    Pair of reports describes acoustic-levitation systems in which only one acoustic resonance mode excited, and only one driver needed. Systems employ levitation chambers of rectangular and cylindrical geometries. Reports first describe single mode concept and indicate which modes used to levitate sample without rotation. Reports then describe systems in which controlled rotation of sample introduced.

  12. Advanced Competencies for School Bus Drivers.

    Science.gov (United States)

    Illinois State Board of Education, Springfield.

    Four units are provided for formal classroom instruction in advanced competencies for school bus drivers in Illinois. Units cover passenger control, accidents and emergencies, detecting hazards, and first aid. Each unit contains some or all of the following components: table of contents; a list of objectives; informative material, including an…

  13. Driver electronic device use in 2008

    Science.gov (United States)

    2009-09-01

    The 2008 hand-held cell phone use rate translates into 812,000 vehicles being driven by someone using a hand-held cell phone at any given daylight moment.1 It also translates into an estimated 11 percent of the vehicles whose drivers were using some ...

  14. Driver Education for Motorcycle Operation. Final Report.

    Science.gov (United States)

    Council, Forrest M.; And Others

    A three-year pilot project was conducted to evaluate the feasibility of implementing a statewide off-road motorcycle training program for beginning drivers in North Carolina. The first year of the program involved approximately 422 students from five locations, the second year involved seven sites across the State. The three basic criteria for the…

  15. Compulsory treatment of 50 alcoholic drunken drivers

    African Journals Online (AJOL)

    1983-02-12

    Feb 12, 1983 ... Fifty alcoholic drunken drivers receivi~g treatment as part of a suspended ... rehabilitation centres (1 patient died too early to allow for adequate .... Prison sentences were imposed on 10 (of whom 1 subsequently re-attended ...

  16. TMACS Test Procedure TP009: Acromag Driver

    International Nuclear Information System (INIS)

    Washburn, S.J.

    1994-01-01

    The TMACS Software Project Test Procedures translate the project's acceptance criteria into test steps. Software releases are certified when the affected Test Procedures are successfully performed and the customers authorize installation of these changes. This Test Procedure tests the TMACS Acromag Software Driver (Bridge Code)

  17. Evaluation of Beginner Driver Education in Oregon

    Directory of Open Access Journals (Sweden)

    Dan Mayhew

    2017-02-01

    Full Text Available Although driver education (DE is widely accepted as an effective teen driver safety measure and widely available in the United States, Canada and elsewhere, evaluations have generally failed to show that such formal programs actually produce safer drivers. To address the issue of safety effects as part of a larger investigation, two studies were conducted to examine whether the Oregon Department of Transportation (ODOT-approved DE program was associated with reductions in collisions and convictions. In the first study, DE status among a relatively small sample of teens who completed an online survey was not found to have a significant effect on collisions and convictions. In the second study, of a much larger population of teen drivers, DE status was associated with a lower incidence of collisions and convictions. On balance, this suggests that the safety effects of DE are either neutral, based on the results of the first Oregon study, or cautiously optimistic based on the results of the second study. The implications of these findings are discussed in terms of making improvements in DE that are evidence-based, and the need for further evaluation to establish that improved and new programs meet their safety objectives.

  18. Driver Performance Model: 1. Conceptual Framework

    National Research Council Canada - National Science Library

    Heimerl, Joseph

    2001-01-01

    ...'. At the present time, no such comprehensive model exists. This report discusses a conceptual framework designed to encompass the relationships, conditions, and constraints related to direct, indirect, and remote modes of driving and thus provides a guide or 'road map' for the construction and creation of a comprehensive driver performance model.

  19. 29 CFR 782.4 - Drivers' helpers.

    Science.gov (United States)

    2010-07-01

    ... interstate or foreign commerce, because, in the case of an accident or other emergency and in other respects... accidents occur, they help the driver in obtaining aid and protect the vehicle from oncoming traffic. (c) In... commerce within the meaning of the Motor Carrier Act. (Ispass v. Pyramid Motor Freight Corp., 152 F. (2d...

  20. A review of lateral driver support systems

    NARCIS (Netherlands)

    Tideman, Martijn; van der Voort, Mascha C.; van Arem, Bart; Tillema, Frans; Dailey, D.

    2007-01-01

    Lateral driver support systems have the potential to reduce the number of accidents associated with -both intentional and unintentional -lane departures. Additionally, such systems may increase driving comfort and stimulate a more efficient traffic flow, thereby reducing traffic emissions and the

  1. Drivers and barriers for bioenergy trade

    NARCIS (Netherlands)

    Junginger, Martin; Schouwenberg, Peter Paul; Nikolaisen, Lars; Andrade, Onofre

    2014-01-01

    There are several drivers responsible for the strong increase in biomass trade over the past decade: concerns regarding the effects of climate change remain unchanged, and policy targets for renewable energy for 2020 have so far remained (largely) intact despite the economic crisis. At the same

  2. Line driver with adaptive output impedance

    NARCIS (Netherlands)

    Nauta, Bram

    2006-01-01

    Abstract not available for DE69834793D Abstract of corresponding document: US5973490 A line driver comprising a first transistor (M1), a first amplifier (A1) and a reference resistor (10) for converting an input voltage (Vin) to a first current (i1) through the first transistor (M1). A second

  3. Line driver with adaptive output impedance

    NARCIS (Netherlands)

    Nauta, Bram

    1998-01-01

    Abstract not available for DE69834793D Abstract of corresponding document: US5973490 A line driver comprising a first transistor (M1), a first amplifier (A1) and a reference resistor (10) for converting an input voltage (Vin) to a first current (i1) through the first transistor (M1). A second

  4. Drivers of Diversification in Individual Life Courses

    DEFF Research Database (Denmark)

    Hernandez-Pacheco, Raisa; Steiner, Ulrich K

    2017-01-01

    Heterogeneity in life courses among individuals of a population influences the speed of adaptive evolutionary processes, but it is less clear how biotic and abiotic environmental fluctuations influence such heterogeneity. We investigate principal drivers of variability in sequence of stages durin...

  5. Truck drivers as stakeholders in cooperative driving

    NARCIS (Netherlands)

    de Bruijn, F.; Terken, J.M.B.; Aarts, E.; de Ruyter, B.; Markopoulos, P.; van Loenen, E.; Wichert, R.; Schouten, B.; Terken, J.M.B.; van Kranenburg, R.; Den Ouden, E.; O'Hare, G.

    2014-01-01

    Cooperative driving for trucks has been claimed to bring substantial benefits for society and fleet owners because of better throughput and reduced fuel consumption, but benefits for truck drivers are questionable. While most work on cooperative driving focuses on the technology, the current paper

  6. ITER driver blanket, European Community design

    International Nuclear Information System (INIS)

    Simbolotti, G.; Zampaglione, V.; Ferrari, M.; Gallina, M.; Mazzone, G.; Nardi, C.; Petrizzi, L.; Rado, V.; Violante, V.; Daenner, W.; Lorenzetto, P.; Gierszewski, P.; Grattarola, M.; Rosatelli, F.; Secolo, F.; Zacchia, F.; Caira, M.; Sorabella, L.

    1993-01-01

    Depending on the final decision on the operation time of ITER (International Thermonuclear Experimental Reactor), the Driver Blanket might become a basic component of the machine with the main function of producing a significant fraction (close to 0.8) of the tritium required for the ITER operation, the remaining fraction being available from external supplies. The Driver Blanket is not required to provide reactor relevant performance in terms of tritium self-sufficiency. However, reactor relevant reliability and safety are mandatory requirements for this component in order not to significantly afftect the overall plant availability and to allow the ITER experimental program to be safely and successfully carried out. With the framework of the ITER Conceptual Design Activities (CDA, 1988-1990), a conceptual design of the ITER Driver Blanket has been carried out by ENEA Fusion Dept., in collaboration with ANSALDO S.p.A. and SRS S.r.l., and in close consultation with the NET Team and CFFTP (Canadian Fusion Fuels Technology Project). Such a design has been selected as EC (European Community) reference design for the ITER Driver Blanket. The status of the design at the end of CDA is reported in the present paper. (orig.)

  7. Driver Circuit For High-Power MOSFET's

    Science.gov (United States)

    Letzer, Kevin A.

    1991-01-01

    Driver circuit generates rapid-voltage-transition pulses needed to switch high-power metal oxide/semiconductor field-effect transistor (MOSFET) modules rapidly between full "on" and full "off". Rapid switching reduces time of overlap between appreciable current through and appreciable voltage across such modules, thereby increasing power efficiency.

  8. Innovation drivers and barriers in food processing

    NARCIS (Netherlands)

    Fortuin, F.T.J.M.; Omta, S.W.F.

    2009-01-01

    Purpose - The food processing industry, confronted with increased global competition and more stringent customer demands, is pressurized to improve the pace and quality of its innovation processes. This paper aims to find out what factors constitute the main drivers and barriers to innovation and to

  9. Kernel Korner : The Linux keyboard driver

    NARCIS (Netherlands)

    Brouwer, A.E.

    1995-01-01

    Our Kernel Korner series continues with an article describing the Linux keyboard driver. This article is not for "Kernel Hackers" only--in fact, it will be most useful to those who wish to use their own keyboard to its fullest potential, and those who want to write programs to take advantage of the

  10. The antilock braking system anomaly: a drinking driver problem?

    Science.gov (United States)

    Harless, David W; Hoffer, George E

    2002-05-01

    Antilock braking systems (ABS) have held promise for reducing the incidence of accidents because they reduce stopping times on slippery surfaces and allow drivers to maintain steering control during emergency braking. Farmer et al. (Accident Anal. Prevent. 29 (1997) 745) provide evidence that antilock brakes are beneficial to nonoccupants: a set of 1992 model General Motors vehicles equipped with antilock brakes were involved in significantly fewer fatal crashes in which occupants of other vehicles, pedestrians, or bicyclists were killed. But, perversely, the risk of death for occupants of vehicles equipped with antilock brakes increased significantly after adoption. Farmer (Accident Anal. Prevent. 33 (2001) 361) updates the analysis for 1996- 1998 and finds a significant attenuation in the ABS anomaly. Researchers have put forward two hypotheses to explain this antilock brake anomaly: risk compensation and improper operation of antilock brake-equipped vehicles. We provide strong evidence for the improper operation hypothesis by showing that the antilock brake anomaly is confined largely to drinking drivers. Further, we show that the attenuation phenomenon occurs consistently after the first three to four years of vehicle service.

  11. Secondary Behavior of Drivers on Cell Phones.

    Science.gov (United States)

    Farmer, Charles M; Klauer, Sheila G; McClafferty, Julie A; Guo, Feng

    2015-01-01

    The objective of this study was to determine whether cell phone use by drivers leads to changes in the frequency of other types of potentially distracting behavior. There were 2 main questions of interest: (1) As each driver changes cell phone use, does he or she change the amount of driving time spent on other distracting behavior? (2) As each driver changes cell phone use, does he or she change the amount of driving time spent looking away from the driving task? Day-to-day driving behavior of 105 volunteer subjects was monitored over a period of 1 year. The amount of driving time during each trip spent on tasks secondary to driving (or looking away from the driving task) was correlated to the amount of time on a cell phone, taking into account the relationships among trips taken by the same driver. Drivers spent 42% of the time engaging in at least one secondary activity. Drivers were talking on a cell phone 7% of the time, interacting in some other way with a cell phone 5% of the time, and engaging in some other secondary activity (sometimes in conjunction with cell phone use) 33% of the time. Other than cell phone use, the most common secondary activities were interacting with a passenger (12% of driving time), holding but not otherwise interacting with an object (6%), and talking/singing/dancing to oneself (5%). Drivers were looking straight forward 81% of the time, forward left or right 5% of time, in a mirror 4% of the time, and elsewhere (eyes off driving task) 10% of time. On average, for each 1 percentage point increase in cell phone talking, the other secondary behavior rate decreased by 0.28 percentage points (P cell phone interaction per trip, the other secondary behavior rate decreased by 0.08 percentage points (P =.0558), but the rate of eyes off driving task increased by 0.06 percentage points (P cell phone can be distracting from the driving task, other secondary activities can be equally or more distracting, at least as measured by eye glances

  12. Driver ASICs for Advanced Deformable Mirrors, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall goal of the SBIR program is to develop a new Application Specified Integrated Circuit (ASIC) driver to be used in driver electronics of a deformable...

  13. The Effect of Passengers on Teen Driver Behavior

    Science.gov (United States)

    2012-04-01

    A number of studies have shown that passengers substantially increase the risk of crashes for young, novice drivers. This increased risk may result from distractions that young passengers create for drivers. Alternatively, the presence of passengers ...

  14. The effect of passengers on teen driver behavior : traffic tech.

    Science.gov (United States)

    2012-04-01

    A number of studies have shown that passengers substantially : increase the risk of crashes for young, novice drivers. : This increased risk may result from distractions that young : passengers create for drivers. Alternatively, the presence : of pas...

  15. Driver education practices in selected states : traffic tech.

    Science.gov (United States)

    2011-07-01

    Teen drivers have the highest crash rate per mile driven of any : age group (Williams, Ferguson, & Wells, 2005). Immaturity and : inexperience are two explanations for why novice teen drivers : have such a high crash risk (Arnett, 1992; Mayhew, Simps...

  16. 78 FR 26417 - Qualification of Drivers; Application for Exemptions; Hearing

    Science.gov (United States)

    2013-05-06

    ... Cook Mr. Cook holds a driver's license from Virginia. He would like to drive a CMV in interstate.... Thomas Prickett Mr. Prickett holds a driver's license from Minnesota. He would like to drive a CMV in...

  17. 77 FR 70530 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

    Science.gov (United States)

    2012-11-26

    ...-0348] Qualification of Drivers; Exemption Applications; Diabetes Mellitus AGENCY: Federal Motor Carrier Safety Administration (FMCSA), DOT. ACTION: Notice of applications for exemption from the diabetes... revision must provide for individual assessment of drivers with diabetes mellitus, and be consistent with...

  18. Development of a statistical method for predicting human driver decisions.

    Science.gov (United States)

    2015-09-01

    As autonomous vehicles enter the fleet, there will be a long period when these vehicles will have to interact with : human drivers. One of the challenges for autonomous vehicles is that human drivers do not communicate their : decisions well. However...

  19. A UNIX device driver for a Translink II Transputer board

    International Nuclear Information System (INIS)

    Wiley, J.C.

    1991-01-01

    A UNIX device driver for a TransLink II Transputer board is described. A complete listing of the code is presented. The device driver allows a transputer array to be used with the A/UX operating system

  20. Improving safety of teenage and young adult drivers in Kansas.

    Science.gov (United States)

    2013-12-01

    Statistics show that young drivers have higher motor vehicle crash rates compared to other age groups. This study investigated : characteristics, contributory causes, and factors which increase injury severity of young driver crashes in Kansas by com...

  1. Methodology to evaluate teen driver training programs : [brief].

    Science.gov (United States)

    2014-03-01

    In the United States, teenage drivers are more at risk of being involved in crashes than : any other age group. Statistics reveal a clear need for improving teenagers driving : skills, judgment and behavior. Driver education programs are a crucial...

  2. Attitudes of truck drivers and carriers on the use of electronic logging devices and driver harassment.

    Science.gov (United States)

    2014-11-01

    The research contained herein is an examination of managerial harassment experienced by drivers, and whether harassment is associated with the method used to log hours of service (HOS). Similar information was gathered from a sample of carriers. : Tr...

  3. An evidence-based review: distracted driver.

    Science.gov (United States)

    Llerena, Luis E; Aronow, Kathy V; Macleod, Jana; Bard, Michael; Salzman, Steven; Greene, Wendy; Haider, Adil; Schupper, Alex

    2015-01-01

    Cell phone use and texting are prevalent within society and have thus pervaded the driving population. This technology is a growing concern within the confines of distracted driving, as all diversions from attention to the road have been shown to increase the risk of crashes. Adolescent, inexperienced drivers, who have the greatest prevalence of texting while driving, are at a particularly higher risk of crashes because of distraction. Members of the Injury Control Violence Prevention Committee of the Eastern Association for the Surgery of Trauma performed a PubMed search of articles related to distracted driving and cell phone use as a distractor of driving between 2000 and 2013. A total of 19 articles were found to merit inclusion as evidence in the evidence-based review. These articles provided evidence regarding the relationship between distracted driving and crashes, cell phone use contributing to automobile accidents, and/or the relationship between driver experience and automobile accidents. (Adjust methods/results sections to the number of articles that correctly corresponds to the number of references, as well as the methodology for reference inclusion.) Based on the evidence reviewed, we can recommend the following. All drivers should minimize all in-vehicle distractions while on the road. All drivers should not text or use any touch messaging system (including the use of social media sites such as Facebook and Twitter) while driving. Younger, inexperienced drivers should especially not use cell phones, texting, or any touch messaging system while driving because they pose an increased risk for death and injury caused by distractions while driving.

  4. Advanced driver assistance systems for teen drivers: Teen and parent impressions, perceived need, and intervention preferences.

    Science.gov (United States)

    Weiss, Eve; Fisher Thiel, Megan; Sultana, Nahida; Hannan, Chloe; Seacrist, Thomas

    2018-02-28

    From the advent of airbags to electronic stability control, technological advances introduced into automobile design have significantly reduced injury and death from motor vehicle crashes. These advances are especially pertinent among teen drivers, a population whose leading cause of death is motor vehicle crashes. Recently developed advanced driver assistance systems (ADAS) have the potential to compensate for skill deficits and reduce overall crash risk. Yet, ADAS is only effective if drivers are willing to use it. Limited research has been conducted on the suitability of ADAS for teen drivers. The goal of this study is to identify teen drivers' perceived need for ADAS, receptiveness to in-vehicle technology, and intervention preferences. The long-term goal is to understand public perceptions and barriers to ADAS use and to help determine how these systems must evolve to meet the needs of the riskiest driving populations. Three focus groups (N = 24) were conducted with licensed teen drivers aged 16-19 years and 2 focus groups with parents of teen drivers (N = 12). Discussion topics included views on how ADAS might influence driving skills and behaviors; trust in technology; and data privacy. Discussions were transcribed; the team used conventional content analysis and open coding methods to identify 12 coding domains and code transcripts with NVivo 10. Interrater reliability testing showed moderate to high kappa scores. Overall, participants recognized potential benefits of ADAS, including improved safety and crash reduction. Teens suggested that ADAS is still developing and therefore has potential to malfunction. Many teens reported a greater trust in their own driving ability over vehicle technology. They expressed that novice drivers should learn to drive on non-ADAS-equipped cars and that ADAS should be considered a supplemental aid. Many teens felt that overreliance on ADAS may increase distracted driving or risky behaviors among teens. Parents also

  5. Inertial confinement fusion driver enhancements: Final focusing systems and compact heavy-ion driver designs

    International Nuclear Information System (INIS)

    Bieri, R.L.

    1991-01-01

    Required elements of an inertial confinement fusion power plant are modeled and discussed. A detailed analysis of two critical elements of candidate drivers is done, and new component designs are proposed to increase the credibility and feasibility of each driver system. An analysis of neutron damage to the final elements of a laser focusing system is presented, and multilayer -- dielectric mirrors are shown to have damage lifetimes which axe too short to be useful in a commercial power plant. A new final-focusing system using grazing incidence metal mirrors to protect sensitive laser optics is designed and shown to be effective in extending the lifetime of the final focusing system. The reflectivities and damage limits of grazing incidence metal mirrors are examined in detail, and the required mirror sizes are shown to be compatible with the beam sizes and illumination geometries currently envisioned for laser drivers. A detailed design and analysis is also done for compact arrays of superconducting magnetic quadrupoles, which are needed in a multi-beam heavy-ion driver. The new array model is developed in more detail than some previous conceptual designs and models arrays which are more compact than arrays scaled from existing single -- quadrupole designs. The improved integrated model for compact arrays is used to compare the effects of various quadrupole array design choices on the size and cost of a heavy-ion driver. Array design choices which significantly affect the cost of a heavy-ion driver include the choice of superconducting material and the thickness of the collar used to support the winding stresses. The effect of these array design choices on driver size and cost is examined and the array model is used to estimate driver cost savings and performance improvements attainable with aggressive quadrupole array designs with high-performance superconductors

  6. Odds of fault and factors for out-of-state drivers in crashes in four states of the USA.

    Science.gov (United States)

    Harootunian, Kristine; Lee, Brian H Y; Aultman-Hall, Lisa

    2014-11-01

    Drivers outside their country of residence are at a safety disadvantage when compared to native counterparts. This research aimed to (1) investigate if out-of-state drivers in the United States experienced the same vulnerabilities as foreign drivers, and (2) examine the relations of out-of-state crashes to various human and environmental factors. Crash data from Florida, Maine, Minnesota, and Nevada was analyzed to model fault using logistic regressions. Univariate regressions showed that out-of-state drivers had increased odds of fault, ranging from 17% to 92%, for a single-vehicle crash compared to in-state drivers in all states except Florida, where there was no difference between groups. Odds were elevated for out-of-state drivers in two-vehicle crashes by 3% to 19% in all states except Florida and Minnesota, where, again, there was no difference between groups. Human and environmental factors such as age, sex, driving conditions, and seasons were examined with multivariate regressions for in- and out-of-state groups separately, and their odds ratios were compared. For single-vehicle crashes age, sex, road grade, surface condition, light conditions, and day of week were factors that increased at least one of the two groups' odds of fault in all states. Sex, surface condition, and light conditions increased the odds of fault for at least one of the groups in two-vehicle crashes in all four states. Factors that consistently increased odds of fault for both single- and two-vehicle crashes were males, non-vehicle owners, curves, and inclement weather. Although there were several factors in each state that increased odds of fault for out-of-state drivers, no factors consistently increased odds of fault for out-of-state drivers across all four states. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Schoolbus driver performance can be improved with driver training, safety incentivisation, and vehicle roadworthy modifications

    Directory of Open Access Journals (Sweden)

    A van Niekerk

    2017-03-01

    Full Text Available In South Africa (SA, the school transport industry provides millions of children with a means of travelling to and from school. The industry has, however, been reported to be plagued by widespread safety concerns. The consequent road traffic incidents have often been attributed to driver factors, including driving in excess of legal speeds or at inappropriate speeds; driving while under the influence of alcohol, while sleepy or fatigued; or driving without using protective equipment for vehicle occupants. There are currently very few SA interventions that specifically target this important industry role-player. The Safe Travel to School Programme was recently implemented by a national child safety agency, with a focus on driver road safety awareness, defensive driver training, eye- testing, vehicle roadworthy inspections with selected upgrades, incentives for safe performance, and implementation of a vehicle telematics tracking system with regular, individual driving behaviour information updates. This quasi-experimental study offers an evaluation of the initial impact on safety performance of this telematics-based driver and vehicle safety intervention in terms of speeding, acceleration, braking, cornering, and time-of-day driving, and compares the school transport driver performance with that of general motorists. Despite concerns that some school transport vehicles are used for multiple purposes outside of school transport duties, at night, and for longer distances, overall these vehicles recorded lower percentages of speeding, lower harsh braking, and lower average harsh cornering and acceleration than general drivers.

  8. Induction linac drivers for commercial heavy-ion beam fusion

    International Nuclear Information System (INIS)

    Keefe, D.

    1987-11-01

    This paper discusses induction linac drivers necessary to accelerate heavy ions at inertial fusion targets. Topics discussed are: driver configurations, the current-amplifying induction linac, high current beam behavior and emittance growth, new considerations for driver design, the heavy ion fusion systems study, and future studies. 13 refs., 6 figs., 1 tab

  9. Prevalence of Psychoactive Drug Use by Taxi Drivers in Nigeria ...

    African Journals Online (AJOL)

    Aim: To ascertain the prevalence and nature of psychoactive drug use amongst taxi drivers in Nigeria. Materials and Method: A total of 192 taxi drivers in Enugu, South East Nigeria was studied using a questionnaire. Information obtained from the questionnaire included socio-demographic characteristics of the drivers, ...

  10. Pattern of Eye Diseases among Commercial Intercity Vehicle Drivers ...

    African Journals Online (AJOL)

    Objective: To determine the pattern of eye diseases among commercial intercity vehicle drivers (CIVDs) in Ilorin, Nigeria. Design: A cross-sectional descriptive study. Methodology: Out of the estimated 450 drivers operating in the five major motor parks for CIVDs in Ilorin, 399 consecutive drivers participated in the study.

  11. 18- to 24-year-olds : young drivers.

    NARCIS (Netherlands)

    2016-01-01

    The fatality rate (fatalities per distance travelled) of young drivers (18- to 24-year-olds) is more than five times higher than that of drivers between the ages of 30 and 59 years. The fatality rate of young males is even as much as ten times higher. The high risk of young drivers is due to both

  12. Driver's anger state identification by using facial expression in ...

    African Journals Online (AJOL)

    Preventive safety system of vehicle is highlighted to reduce the number of traffic accidents. Driver's state adaptive driving safety system may be one of candidates of the safety system. Identifying driver's psychosomatic states is indispensable to establish those safety systems. Anger of driver state is often seen in traffic ...

  13. High frequency MOSFET gate drivers technologies and applications

    CERN Document Server

    Zhang, Zhiliang

    2017-01-01

    This book describes high frequency power MOSFET gate driver technologies, including gate drivers for GaN HEMTs, which have great potential in the next generation of switching power converters. Gate drivers serve as a critical role between control and power devices.

  14. 75 FR 32983 - Commercial Driver's License (CDL) Standards: Exemption

    Science.gov (United States)

    2010-06-10

    ...-28480] Commercial Driver's License (CDL) Standards: Exemption AGENCY: Federal Motor Carrier Safety... commercial driver's license (CDL) as required by current regulations. FMCSA reviewed NAAA's application for... demonstrate alternatives its members would employ to ensure that their commercial motor vehicle (CMV) drivers...

  15. Mandatory Driver Training and Road Safety: The Quebec Experience.

    Science.gov (United States)

    Potvin, Louise; And Others

    1988-01-01

    1983 legislation making driver training courses mandatory for any person in Quebec seeking a first driver's license had no effect on the risk of accident or the mortality/morbidity rate for newly licensed drivers over 18. However, since 1983 more women under 18 are becoming licensed, and their risks may be increased. (Author/BJV)

  16. Do young novice drivers overestimate their driving skills?

    NARCIS (Netherlands)

    Craen, S. de Twisk, D.A.M. Hagenzieker, M.P. Elffers, H. & Brookhuis, K.A.

    2007-01-01

    In this study the authors argue that, in order to sufficiently adapt to task demands in traffic, drivers have to make an assessment of their own driving skills. There are indications that drivers in general, and novice drivers in particular, overestimate their driving skills. The objective of this

  17. Licensing and Other Controls of the Drinking Driver.

    Science.gov (United States)

    Waller, Patricia F.

    Driver licensing, the only state program with the opportunity for routine personal contact with every driver, has unmatched potential for both general and specific countermeasures to the problem of drunk driving. General countermeasures apply to large groups of drivers prior to the occurrence of any infraction. They may be considered basically…

  18. Traffic safety issues in North Dakota : phase II : driver knowledge, attitude, behavior and beliefs : focus group : young male drivers

    Science.gov (United States)

    2008-10-01

    Traffic safety is a widespread social concern. Tackling the problem requires understanding the people : who are driving. This includes information about driver behavior, but also about perceptions these drivers : hold regarding their driving. North D...

  19. Resource utilization and outcomes of intoxicated drivers.

    Science.gov (United States)

    Cherry, Robert A; Nichols, Pamela A; Snavely, Theresa M; Camera, Lindsay J; Mauger, David T

    2010-08-05

    The high risk behavior of intoxicated drivers, impaired reaction time, lack of seat belt use, and increased incidence of head injury raises questions of whether pre-hospital use of alcohol leads to a higher injury severity score and worse clinical outcomes. We therefore compared intoxicated and non-intoxicated drivers of motor vehicle crashes with respect to outcome measurements and also describe the resources utilized to achieve those outcomes at our Level 1 trauma center. Retrospective descriptive study (Jan 2002-June 2007) of our trauma registry and financial database comparing intoxicated drivers with blood alcohol levels (BAC) > 80 mg/dl (ETOH > 80) with drivers who had a BAC of 0 mg/dl (ETOH = 0). Drivers without a BAC drawn or who had levels ranging from 1 mg/dL to 80 mg/dL were excluded. Data was collected on demographic information (age, gender, injury severity score or ISS), outcome variables (mortality, complications, ICU and hospital LOS, ventilator days) and resource utilization (ED LOS, insurance, charges, costs, payments). p 80; stratified chi square. Out of 1732 drivers, the combined study group (n = 987) of 623 ETOH = 0 and 364 ETOH > 80 had a mean age of 38.8 +/- 17.9, ISS of 18.0 +/- 12.1, and 69.8%% male. There was no difference in ISS (p = 0.67) or complications (p = 0.38). There was a trend towards decreased mortality (p = 0.06). The ETOH = 0 group had more patients with a prolonged ICU LOS (>/= 5 days), ventilator days (>/= 8 days), and hospital LOS (> 14 days) when compared to the ETOH > 80 group (p 80 group tended to be self pay (4.9% vs. 0.7%, p pay, less likely to have charges > $50K, and less likely to pay >/= 90% of the charges. Further research using multivariable analysis is needed to determine if these apparent outcomes differences are driven by acute intoxication, and the tendency for endotracheal intubation and ICU admission, rather than injury severity.

  20. Drivers' reactions to sudden braking by lead car under varying workload conditions; towards a driver support system

    NARCIS (Netherlands)

    Schaap, T. W.; van der Horst, A. R. A.; van Arem, B.; Brookhuis, K. A.

    2008-01-01

    At urban intersections drivers handle multiple tasks simultaneously, making urban driving a complex task. An advanced driver assistance system may support drivers in this specific driving task, but the design details of such a system need to be determined before they can be fully deployed. A driving

  1. 78 FR 76757 - Regulatory Guidance on Hours of Service of Drivers Rest Break Requirement; Drivers Who Become...

    Science.gov (United States)

    2013-12-19

    ... limitations for unforeseen reasons, is the driver in violation of the Sec. 395.3 rest break provision if more... unforeseen reasons, is not in violation of the Sec. 395.3 rest-break requirements if 8 or more hours have... Regulatory Guidance on Hours of Service of Drivers Rest Break Requirement; Drivers Who Become Ineligible for...

  2. Do young novice drivers overestimate their driving skills more than experienced drivers? : different methods lead to different conclusions.

    NARCIS (Netherlands)

    Craen, S. de Twisk, D.A.M. Hagenzieker, M.P. Elffers, H. & Brookhuis, K.A.

    2011-01-01

    In this study the authors argue that drivers have to make an assessment of their own driving skills, in order to sufficiently adapt to their task demands in traffic. There are indications that drivers in general, but novice drivers in particular, overestimate their driving skills. However, study

  3. Influence of multiple global change drivers on terrestrial carbon storage

    DEFF Research Database (Denmark)

    Yue, Kai; Fornara, Dario A; Yang, Wanqin

    2017-01-01

    The interactive effects of multiple global change drivers on terrestrial carbon (C) storage remain poorly understood. Here, we synthesise data from 633 published studies to show how the interactive effects of multiple drivers are generally additive (i.e. not differing from the sum of their indivi......The interactive effects of multiple global change drivers on terrestrial carbon (C) storage remain poorly understood. Here, we synthesise data from 633 published studies to show how the interactive effects of multiple drivers are generally additive (i.e. not differing from the sum...... additive effects of multiple global change drivers into future assessments of the C storage ability of terrestrial ecosystems....

  4. A COOPERATIVE ASSISTANCE SYSTEM BETWEEN VEHICLES FOR ELDERLY DRIVERS

    Directory of Open Access Journals (Sweden)

    Naohisa HASHIMOTO

    2009-01-01

    Full Text Available This paper proposes a new concept of elderly driver assistance systems, which performs the assistance by cooperative driving between two vehicles, and describes some experiments with elderly drivers. The assistance consists of one vehicle driven by an elderly driver called a guest vehicle and the other driven by a assisting driver called a host vehicle, and the host vehicle assists or escorts the guest vehicle through the inter-vehicle communications. The functions of the systems installed on a single-seat electric vehicle are highly evaluated by subjects of elderly drivers in virtual streets on a test track.

  5. The electromagnetic rocket gun impact fusion driver

    International Nuclear Information System (INIS)

    Winterberg, F.

    1984-01-01

    A macroparticle accelerator to be used as an impact fusion driver is discussed and which can accelerate a small projectile to --200 km/sec over a distance of a few 100 meters. The driver which we have named electromagnetic rocket gun, accelerates a small rocket-like projectile by a travelling magnetic wave. The rocket propellant not only serves as a sink to absorb the heat produced in the projectile by resistive energy losses, but at the same time is also the source of additional thrust through the heating of the propellant to high temperatures by the travelling magnetic wave. The total thrust on the projectile is the sum of the magnetic and recoil forces. In comparison to a rocket, the efficiency is here much larger, with the momentum transferred to the gun barrel of the gun rather than to a tenuous jet. (author)

  6. Flow processes in electric discharge drivers

    Science.gov (United States)

    Baganoff, D.

    1975-01-01

    The performance of an electric discharge shock tube is discussed from the point of view that the conditions at the sonic station are the primary controlling variables (likewise in comparing designs), and that the analysis of the flow on either side of the sonic station should be done separately. The importance of considering mass-flow rate in matching a given driver design to the downstream flow required for a particular shock-wave speed is stressed. It is shown that a driver based on the principle of liquid injection (of H2) is superior to one based on the Ludwieg tube, because of the greater mass-flow rate and the absence of a massive diaphragm.

  7. Drivers of Changes in Product Development Rules

    DEFF Research Database (Denmark)

    Christiansen, John K.; Varnes, Claus J.

    2015-01-01

    regimes. However, the analysis here indicates that there are different drivers, both internal and external, that cause companies to adopt new rules or modify their existing ones, such as changes in organizational structures, organizational conflicts, and changes in ownership or strategy. In addition......Purpose: - The purpose of this research is to investigate the drivers that induce companies to change their rules for managing product development. Most companies use a form of rule-based management approach, but surprisingly little is known about what makes companies change these rules...... 10 years based on three rounds of interviews with 40 managers. Findings: - Previous research has assumed that the dynamics of product development rules are based on internal learning processes, and that increasingly competent management will stimulate the implementation of newer and more complex rule...

  8. Geopolitical drivers of future tourist flows

    Directory of Open Access Journals (Sweden)

    Craig Webster

    2015-03-01

    Full Text Available Purpose – The purpose of this paper is to investigate the major political and economic changes in the world and the likely impact that these changes will bring to tourism and hospitality industries. Design/methodology/approach – The paper adopts a geopolitical perspective on the dynamics of tourist flows, stipulating that geopolitics has a major impact on the size, structure, and direction of these flows. Findings – The paper identifies six geopolitical drivers of tourist flows in the future, namely: the fall of the American Empire, the rise of the BRIC and the PINE countries, increased global political instability, increased importance of regional supranational organisations, greater control of the individuals on a global scale, and the greater importance and power of corporations than national governments. Originality/value – The paper critically evaluates the geopolitical drivers of tourist flows, their likely future development and the impact they have on tourism.

  9. Drivers for Malaysian SMEs to Go Green

    OpenAIRE

    M. Krishna Moorthy; Peter a/l Yacob; Mahendra Kumar a/l Chelliah; Lawrence Arokiasamy

    2012-01-01

    Small and Medium Enterprises (SMEs) around the world have little knowledge about environmental management and do not understand the concept of environmental management. The concept of green is still very new to Malaysian SME owners/managers, although many green conferences, seminars and campaigns have been carried out for quite some time. The concept for green process and products in Malaysia is at the infancy stage. The drivers of environmental behavior in SMEs are relatively under-researche...

  10. Review of advanced driver assistance systems (ADAS)

    Science.gov (United States)

    Ziebinski, Adam; Cupek, Rafal; Grzechca, Damian; Chruszczyk, Lukas

    2017-11-01

    New cars can be equipped with many advanced safety solutions. Airbags, seatbelts and all of the essential passive safety parts are standard equipment. Now cars are often equipped with new advanced active safety systems that can prevent accidents. The functions of the Advanced Driver Assistance Systems are still growing. A review of the most popular available technologies used in ADAS and descriptions of their application areas are discussed in this paper.

  11. Multiprogrammation fast branch driver for microcomputer MICRAL

    International Nuclear Information System (INIS)

    Kaiser, Josef; Lacroix, Jean.

    1975-01-01

    This branch driver allows in association with the FIFO memories of the microcomputer Micral, very fast exchanges with the 7 crates of a CAMAC branch. A CAMAC programm (command, test, read, write) is loaded in the 1K FIFO buffer of the Micral before execution time and executed in sequence at a rate of 1,5μs per CAMAC command. After programm execution, data may be transferred directly on a magnetic tape [fr

  12. Naturalistic distraction and driving safety in older drivers.

    Science.gov (United States)

    Aksan, Nazan; Dawson, Jeffrey D; Emerson, Jamie L; Yu, Lixi; Uc, Ergun Y; Anderson, Steven W; Rizzo, Matthew

    2013-08-01

    In this study, we aimed to quantify and compare performance of middle-aged and older drivers during a naturalistic distraction paradigm (visual search for roadside targets) and to predict older drivers performance given functioning in visual, motor, and cognitive domains. Distracted driving can imperil healthy adults and may disproportionally affect the safety of older drivers with visual, motor, and cognitive decline. A total of 203 drivers, 120 healthy older (61 men and 59 women, ages 65 years and older) and 83 middle-aged drivers (38 men and 45 women, ages 40 to 64 years), participated in an on-road test in an instrumented vehicle. Outcome measures included performance in roadside target identification (traffic signs and restaurants) and concurrent driver safety. Differences in visual, motor, and cognitive functioning served as predictors. Older drivers identified fewer landmarks and drove slower but committed more safety errors than did middle-aged drivers. Greater familiarity with local roads benefited performance of middle-aged but not older drivers.Visual cognition predicted both traffic sign identification and safety errors, and executive function predicted traffic sign identification over and above vision. Older adults are susceptible to driving safety errors while distracted by common secondary visual search tasks that are inherent to driving. The findings underscore that age-related cognitive decline affects older drivers' management of driving tasks at multiple levels and can help inform the design of on-road tests and interventions for older drivers.

  13. Driver steering model for closed-loop steering function analysis

    Science.gov (United States)

    Bolia, Pratiksh; Weiskircher, Thomas; Müller, Steffen

    2014-05-01

    In this paper, a two level preview driver steering control model for the use in numerical vehicle dynamics simulation is introduced. The proposed model is composed of cascaded control loops: The outer loop is the path following layer based on potential field framework. The inner loop tries to capture the driver's physical behaviour. The proposed driver model allows easy implementation of different driving situations to simulate a wide range of different driver types, moods and vehicle types. The expediency of the proposed driver model is shown with the help of developed driver steering assist (DSA) function integrated with a conventional series production (Electric Power steering System with rack assist servo unit) system. With the help of the DSA assist function, the driver is prevented from over saturating the front tyre forces and loss of stability and controllability during cornering. The simulation results show different driver reactions caused by the change in the parameters or properties of the proposed driver model if the DSA assist function is activated. Thus, the proposed driver model is useful for the advanced driver steering and vehicle stability assist function evaluation in the early stage of vehicle dynamics handling and stability evaluation.

  14. Older drivers' risks of at-fault motor vehicle collisions.

    Science.gov (United States)

    Ichikawa, Masao; Nakahara, Shinji; Taniguchi, Ayako

    2015-08-01

    In aging societies, increasing numbers of older drivers are involved in motor vehicle collisions (MVCs), and preserving their safety is a growing concern. In this study, we focused on whether older drivers were more likely to cause MVCs and injuries than drivers in other age groups. To do so we compared at-fault MVC incidence and resulting injury risks by drivers' ages, using data from Japan, a country with a rapidly aging population. The at-fault MVC incidence was calculated based on distance traveled made for non-commercial purposes, and the injury risks posed to at-fault drivers and other road users per at-fault MVCs. We used MVC data for 2010 from the National Police Agency of Japan and driving exposure data from the Nationwide Person Trip Survey conducted by a Japanese governmental ministry in 2010. The at-fault MVC incidence showed a U-shaped curve across the drivers' ages, where teenage and the oldest drivers appeared to be the highest risk groups in terms of causing MVCs, and the incidence was higher for female drivers after age 25. The injury risk older drivers posed to other vehicle occupants because of their at-fault MVCs was lower than for drivers in other age groups, while their own injury risk appeared much higher. As the number of older drivers is increasing, efforts to reduce their at-fault MVCs appear justified. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Anionic lipids and the cytoskeletal proteins MreB and RodZ define the spatio-temporal distribution and function of membrane stress controller PspA in Escherichia coli.

    Science.gov (United States)

    Jovanovic, Goran; Mehta, Parul; Ying, Liming; Buck, Martin

    2014-11-01

    All cell types must maintain the integrity of their membranes. The conserved bacterial membrane-associated protein PspA is a major effector acting upon extracytoplasmic stress and is implicated in protection of the inner membrane of pathogens, formation of biofilms and multi-drug-resistant persister cells. PspA and its homologues in Gram-positive bacteria and archaea protect the cell envelope whilst also supporting thylakoid biogenesis in cyanobacteria and higher plants. In enterobacteria, PspA is a dual function protein negatively regulating the Psp system in the absence of stress and acting as an effector of membrane integrity upon stress. We show that in Escherichia coli the low-order oligomeric PspA regulatory complex associates with cardiolipin-rich, curved polar inner membrane regions. There, cardiolipin and the flotillin 1 homologue YqiK support the PspBC sensors in transducing a membrane stress signal to the PspA-PspF inhibitory complex. After stress perception, PspA high-order oligomeric effector complexes initially assemble in polar membrane regions. Subsequently, the discrete spatial distribution and dynamics of PspA effector(s) in lateral membrane regions depend on the actin homologue MreB and the peptidoglycan machinery protein RodZ. The consequences of loss of cytoplasmic membrane anionic lipids, MreB, RodZ and/or YqiK suggest that the mode of action of the PspA effector is closely associated with cell envelope organization. © 2014 The Authors.

  16. Advances of energy drivers at Osaka

    International Nuclear Information System (INIS)

    Kato, Yoshiaki; Nakai, Sadao; Yamanaka, Chiyoe.

    1979-01-01

    The energy driver development at the Institute of Laser Engineering (ILE), Osaka University, comprises three fields; glass, laser, carbon dioxide laser, and relativistic electron beam. The development of reliable glass lasers has been the main program at ILE. The GEKKO 12 module program was carried out in the fiscal years from 1977 to 1979 in order to develop various laser components and subsystems which are necessary to construct a 20 kJ GEKKO 12 glass laser. The measured gain coefficient of the 200 mm disk amplifier was 0.10/cm corresponding to the αD product of 4.0. The expected peak output power of the system was 2 TW at 0.1 ns and 0.9 kJ at 1 ns. The recent advances in coating techniques will enable to operate this system over 1.3 kJ per beam at 3 ns. Carbon dioxide lasers have been developed as efficient high energy lasers to study the wave length scaling of implosion process. The design and construction of the 10 kJ LEKKO 8 laser system are in progress. Relativistic electron beam machines, being the most cost-effective driver, have been studied to control pulsed power and to investigate electron beam plasma interaction. As the future plans of ILE, the construction of a 100 kJ energy driver from 1958 to 1987 for scientific break-even experiments is considered. (Kato, T.)

  17. Driver behavior following an automatic steering intervention.

    Science.gov (United States)

    Fricke, Nicola; Griesche, Stefan; Schieben, Anna; Hesse, Tobias; Baumann, Martin

    2015-10-01

    The study investigated driver behavior toward an automatic steering intervention of a collision mitigation system. Forty participants were tested in a driving simulator and confronted with an inevitable collision. They performed a naïve drive and afterwards a repeated exposure in which they were told to hold the steering wheel loosely. In a third drive they experienced a false alarm situation. Data on driving behavior, i.e. steering and braking behavior as well as subjective data was assessed in the scenarios. Results showed that most participants held on to the steering wheel strongly or counter-steered during the system intervention during the first encounter. Moreover, subjective data collected after the first drive showed that the majority of drivers was not aware of the system intervention. Data from the repeated drive in which participants were instructed to hold the steering wheel loosely, led to significantly more participants holding the steering wheel loosely and thus complying with the instruction. This study seems to imply that without knowledge and information of the system about an upcoming intervention, the most prevalent driving behavior is a strong reaction with the steering wheel similar to an automatic steering reflex which decreases the system's effectiveness. Results of the second drive show some potential for countermeasures, such as informing drivers shortly before a system intervention in order to prevent inhibiting reactions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Underlying substance abuse problems in drunk drivers.

    Science.gov (United States)

    Snenghi, Rossella; Forza, Giovanni; Favretto, Donata; Sartore, Daniela; Rodinis, Silvia; Terranova, Claudio; Nalesso, Alessandro; Montisci, Massimo; Ferrara, Santo Davide

    2015-01-01

    The aim of this study was to investigate polydrug use in drunk drivers. The experimental study was conducted on 2,072 drunk drivers undergoing a driving license reissue protocol at the Department of Legal Medicine of Padova University Hospital in the period between January 2011 and December 2012. The study protocol involved anamnesis, clinical examination, toxicological history, and toxicological analyses on multiple biological samples. One thousand eight hundred seventy-seven subjects (90.6%) were assessed as fit to drive, and 195 (9.5%) were declared unfit. Among those unfit, 32 subjects (1.6%) were declared unfit due to recent use of an illicit drug (time span drive after completeness of the protocol was established in 1.2% of cases for alcohol disorders and in 5.7% of cases for illicit drug abuse; only one subject was included in both subgroups. Cocaine was the most widely used substance, followed by cannabis, opiates, and psychotropic pharmaceutical drugs. The application of the protocol presented in this study allowed the identification of underlying polydrug use in drunk drivers. The study led to the identification of 6.8% unfit subjects on the basis of alcohol disorders and/or drug abuse, compared to 1.2% of identifiable unfitness if the protocol were limited to the mere assessment of alcohol consumption. The frequent association of alcohol and cocaine is different from other patterns of use in North Europe countries.

  19. Challenges for Older Drivers in Urban, Suburban, and Rural Settings

    Directory of Open Access Journals (Sweden)

    Rashmi P. Payyanadan

    2018-03-01

    Full Text Available Along with age-related factors, geographical settings—urban, suburban, and rural areas—also contribute to the differences in fatal crashes among older drivers. These differences in crash outcomes might be attributed to the various driving challenges faced by older drivers residing in different locations. To understand these challenges from the perspective of the older driver, a focus group study was conducted with drivers 65 and older from urban, suburban, and rural settings. Guided-group interviews were used to assess driving challenges, mobility options, opportunities for driver support systems (DSS, and alternate transportation needs. Content analysis of the interview responses resulted in four categories representing common challenges faced by older drivers across the settings: behavior of other drivers on the road, placement of road signs, reduced visibility of road signs due to age-related decline, and difficulties using in-vehicle technologies. Six categories involved location-specific challenges such as heavy traffic situations for urban and suburban drivers, and multi-destination trips for rural drivers. Countermeasures implemented by older drivers to address these challenges primarily involved route selection and avoidance. Technological advances of DSS systems provide a unique opportunity to support the information needs for route selection and avoidance preferences of drivers. Using the content analysis results, a framework was built to determine additional and modified DSS features to meet the specific challenges of older drivers in urban, suburban, and rural settings. These findings suggest that there is heterogeneity in the driving challenges and preferences of older drivers based on their location. Consequently, DSS technologies and vehicle automation need to be tailored to not only meet the driving safety and mobility needs of older drivers as a population, but also to their driving environment.

  20. Fusion of optimized indicators from Advanced Driver Assistance Systems (ADAS) for driver drowsiness detection.

    Science.gov (United States)

    Daza, Iván García; Bergasa, Luis Miguel; Bronte, Sebastián; Yebes, Jose Javier; Almazán, Javier; Arroyo, Roberto

    2014-01-09

    This paper presents a non-intrusive approach for monitoring driver drowsiness using the fusion of several optimized indicators based on driver physical and driving performance measures, obtained from ADAS (Advanced Driver Assistant Systems) in simulated conditions. The paper is focused on real-time drowsiness detection technology rather than on long-term sleep/awake regulation prediction technology. We have developed our own vision system in order to obtain robust and optimized driver indicators able to be used in simulators and future real environments. These indicators are principally based on driver physical and driving performance skills. The fusion of several indicators, proposed in the literature, is evaluated using a neural network and a stochastic optimization method to obtain the best combination. We propose a new method for ground-truth generation based on a supervised Karolinska Sleepiness Scale (KSS). An extensive evaluation of indicators, derived from trials over a third generation simulator with several test subjects during different driving sessions, was performed. The main conclusions about the performance of single indicators and the best combinations of them are included, as well as the future works derived from this study.

  1. Fusion of Optimized Indicators from Advanced Driver Assistance Systems (ADAS for Driver Drowsiness Detection

    Directory of Open Access Journals (Sweden)

    Iván G. Daza

    2014-01-01

    Full Text Available This paper presents a non-intrusive approach for monitoring driver drowsiness using the fusion of several optimized indicators based on driver physical and driving performance measures, obtained from ADAS (Advanced Driver Assistant Systems in simulated conditions. The paper is focused on real-time drowsiness detection technology rather than on long-term sleep/awake regulation prediction technology. We have developed our own vision system in order to obtain robust and optimized driver indicators able to be used in simulators and future real environments. These indicators are principally based on driver physical and driving performance skills. The fusion of several indicators, proposed in the literature, is evaluated using a neural network and a stochastic optimization method to obtain the best combination. We propose a new method for ground-truth generation based on a supervised Karolinska Sleepiness Scale (KSS. An extensive evaluation of indicators, derived from trials over a third generation simulator with several test subjects during different driving sessions, was performed. The main conclusions about the performance of single indicators and the best combinations of them are included, as well as the future works derived from this study.

  2. Work fatigue in urban bus drivers

    Directory of Open Access Journals (Sweden)

    Teresa Makowiec-Dąbrowska

    2015-10-01

    Full Text Available Background: Bus drivers are a special group of professional drivers who are at a very high risk of fatigue. The aim of the study was to examine whether the driver’s subjective assessment of fatigue allows for the determination of its level and identification of its causes. Material and Methods: The study group comprised 45 randomly selected bus drivers (mean age – 43.7±7.9 years, period of employment as drivers – 14.7±8.6 years. Examinations were performed in all subjects four times – before and after work on the “easy” route (outside the city center, small traffic intensity and before and after work on the “difficult” route (city center, heavy traffic. The fatigue test questionnaire, based on the list of symptoms of fatigue prepared by the Japan Research Committee of Fatigue, was used in the study. Results: The rating of fatigue after the work was significantly higher than that before the work. The profile of fatigue after work was not influenced by the type of route, but the assessment of most symptoms of fatigue reached a higher level after the “difficult” routes and the differences were statistically significant for 7 symptoms. Only the ratings of leg fatigue, feeling of heaviness, and the necessity to squint eyes and gaze with effort reached the higher levels after driving the “easy” routes. It has been found that the level of fatigue was significantly correlated with the job characteristics (driving time, the length of the route, number of stops, etc. and with the abundance of food ingested and type of beverage (coffee vs. others drunk prior to driving. Conclusions: The questionnaire used in our study to assess the subjective feeling of fatigue has proved to be a sensitive and useful tool for indicating the level and causes of fatigue. The relationship between the symptoms of fatigue and the characteristics of job and lifestyle shows that actions must be taken by both the employers and employees to prevent fatigue

  3. Driver behavior analysis for right-turn drivers at signalized intersections using SHRP 2 naturalistic driving study data.

    Science.gov (United States)

    Wu, Jianqing; Xu, Hao

    2017-12-01

    Understanding driver behavior is important for traffic safety and operation, especially at intersections where different traffic movements conflict. While most driver-behavior studies are based on simulation, this paper documents the analysis of driver-behavior at signalized intersections with the SHRP 2 Naturalistic Driving Study (NDS) data. This study analyzes the different influencing factors on the operation (speed control) and observation of right-turn drivers. A total of 300 NDS trips at six signalized intersections were used, including the NDS time-series sensor data, the forward videos and driver face videos. Different factors of drivers, vehicles, roads and environments were studied for their influence on driver behavior. An influencing index function was developed and the index was calculated for each influencing factor to quantitatively describe its influencing level. The influencing index was applied to prioritize the factors, which facilitates development and selection of safety countermeasures to improve intersection safety. Drivers' speed control was analyzed under different conditions with consideration of the prioritized influencing factors. Vehicle type, traffic signal status, conflicting traffic, conflicting pedestrian and driver age group were identified as the five major influencing factors on driver observation. This research revealed that drivers have high acceleration and low observation frequency under Right-Turn-On-Red (RTOR), which constituted potential danger for other roadway users, especially for pedestrians. As speed has a direct influence on crash rates and severities, the revealed speed patterns of the different situations also benefit selection of safety countermeasures at signalized intersections. Published by Elsevier Ltd.

  4. Exploratory multinomial logit model-based driver injury severity analyses for teenage and adult drivers in intersection-related crashes.

    Science.gov (United States)

    Wu, Qiong; Zhang, Guohui; Ci, Yusheng; Wu, Lina; Tarefder, Rafiqul A; Alcántara, Adélamar Dely

    2016-05-18

    Teenage drivers are more likely to be involved in severely incapacitating and fatal crashes compared to adult drivers. Moreover, because two thirds of urban vehicle miles traveled are on signal-controlled roadways, significant research efforts are needed to investigate intersection-related teenage driver injury severities and their contributing factors in terms of driver behavior, vehicle-infrastructure interactions, environmental characteristics, roadway geometric features, and traffic compositions. Therefore, this study aims to explore the characteristic differences between teenage and adult drivers in intersection-related crashes, identify the significant contributing attributes, and analyze their impacts on driver injury severities. Using crash data collected in New Mexico from 2010 to 2011, 2 multinomial logit regression models were developed to analyze injury severities for teenage and adult drivers, respectively. Elasticity analyses and transferability tests were conducted to better understand the quantitative impacts of these factors and the teenage driver injury severity model's generality. The results showed that although many of the same contributing factors were found to be significant in the both teenage and adult driver models, certain different attributes must be distinguished to specifically develop effective safety solutions for the 2 driver groups. The research findings are helpful to better understand teenage crash uniqueness and develop cost-effective solutions to reduce intersection-related teenage injury severities and facilitate driver injury mitigation research.

  5. A learning-based autonomous driver: emulate human driver's intelligence in low-speed car following

    Science.gov (United States)

    Wei, Junqing; Dolan, John M.; Litkouhi, Bakhtiar

    2010-04-01

    In this paper, an offline learning mechanism based on the genetic algorithm is proposed for autonomous vehicles to emulate human driver behaviors. The autonomous driving ability is implemented based on a Prediction- and Cost function-Based algorithm (PCB). PCB is designed to emulate a human driver's decision process, which is modeled as traffic scenario prediction and evaluation. This paper focuses on using a learning algorithm to optimize PCB with very limited training data, so that PCB can have the ability to predict and evaluate traffic scenarios similarly to human drivers. 80 seconds of human driving data was collected in low-speed (car-following scenarios. In the low-speed car-following tests, PCB was able to perform more human-like carfollowing after learning. A more general 120 kilometer-long simulation showed that PCB performs robustly even in scenarios that are not part of the training set.

  6. X3 expansion tube driver gas spectroscopy and temperature measurements

    Science.gov (United States)

    Parekh, V.; Gildfind, D.; Lewis, S.; James, C.

    2017-11-01

    The University of Queensland's X3 facility is a large, free-piston driven expansion tube used for super-orbital and high Mach number scramjet aerothermodynamic studies. During recent development of new scramjet test flow conditions, experimentally measured shock speeds were found to be significantly lower than that predicted by initial driver performance calculations. These calculations were based on ideal, isentropic compression of the driver gas and indicated that loss mechanisms, not accounted for in the preliminary analysis, were significant. The critical determinant of shock speed is peak driver gas sound speed, which for a given gas composition depends on the peak driver gas temperature. This temperature may be inaccurately estimated if an incorrect fill temperature is assumed, or if heat losses during driver gas compression are significant but not accounted for. For this study, the ideal predicted peak temperature was 3750 K, without accounting for losses. However, a much lower driver temperature of 2400 K is suggested based on measured experimental shock speeds. This study aimed to measure initial and peak driver gas temperatures for a representative X3 operating condition. Examination of the transient temperatures of the driver gas and compression tube steel wall during the initial fill process showed that once the filling process was complete, the steady-state driver gas temperature closely matched the tube wall temperature. Therefore, while assuming the gas is initially at the ambient laboratory temperature is not a significant source of error, it can be entirely mitigated by simply monitoring tube wall temperature. Optical emission spectroscopy was used to determine the driver gas spectra after diaphragm rupture; the driver gas emission spectrum exhibited a significant continuum radiation component, with prominent spectral lines attributed to contamination of the gas. A graybody approximation of the continuum suggested a peak driver gas temperature of

  7. X3 expansion tube driver gas spectroscopy and temperature measurements

    Science.gov (United States)

    Parekh, V.; Gildfind, D.; Lewis, S.; James, C.

    2018-07-01

    The University of Queensland's X3 facility is a large, free-piston driven expansion tube used for super-orbital and high Mach number scramjet aerothermodynamic studies. During recent development of new scramjet test flow conditions, experimentally measured shock speeds were found to be significantly lower than that predicted by initial driver performance calculations. These calculations were based on ideal, isentropic compression of the driver gas and indicated that loss mechanisms, not accounted for in the preliminary analysis, were significant. The critical determinant of shock speed is peak driver gas sound speed, which for a given gas composition depends on the peak driver gas temperature. This temperature may be inaccurately estimated if an incorrect fill temperature is assumed, or if heat losses during driver gas compression are significant but not accounted for. For this study, the ideal predicted peak temperature was 3750 K, without accounting for losses. However, a much lower driver temperature of 2400 K is suggested based on measured experimental shock speeds. This study aimed to measure initial and peak driver gas temperatures for a representative X3 operating condition. Examination of the transient temperatures of the driver gas and compression tube steel wall during the initial fill process showed that once the filling process was complete, the steady-state driver gas temperature closely matched the tube wall temperature. Therefore, while assuming the gas is initially at the ambient laboratory temperature is not a significant source of error, it can be entirely mitigated by simply monitoring tube wall temperature. Optical emission spectroscopy was used to determine the driver gas spectra after diaphragm rupture; the driver gas emission spectrum exhibited a significant continuum radiation component, with prominent spectral lines attributed to contamination of the gas. A graybody approximation of the continuum suggested a peak driver gas temperature of

  8. Deep Learning-Based Gaze Detection System for Automobile Drivers Using a NIR Camera Sensor.

    Science.gov (United States)

    Naqvi, Rizwan Ali; Arsalan, Muhammad; Batchuluun, Ganbayar; Yoon, Hyo Sik; Park, Kang Ryoung

    2018-02-03

    A paradigm shift is required to prevent the increasing automobile accident deaths that are mostly due to the inattentive behavior of drivers. Knowledge of gaze region can provide valuable information regarding a driver's point of attention. Accurate and inexpensive gaze classification systems in cars can improve safe driving. However, monitoring real-time driving behaviors and conditions presents some challenges: dizziness due to long drives, extreme lighting variations, glasses reflections, and occlusions. Past studies on gaze detection in cars have been chiefly based on head movements. The margin of error in gaze detection increases when drivers gaze at objects by moving their eyes without moving their heads. To solve this problem, a pupil center corneal reflection (PCCR)-based method has been considered. However, the error of accurately detecting the pupil center and corneal reflection center is increased in a car environment due to various environment light changes, reflections on glasses surface, and motion and optical blurring of captured eye image. In addition, existing PCCR-based methods require initial user calibration, which is difficult to perform in a car environment. To address this issue, we propose a deep learning-based gaze detection method using a near-infrared (NIR) camera sensor considering driver head and eye movement that does not require any initial user calibration. The proposed system is evaluated on our self-constructed database as well as on open Columbia gaze dataset (CAVE-DB). The proposed method demonstrated greater accuracy than the previous gaze classification methods.

  9. Using shadow page cache to improve isolated drivers performance.

    Science.gov (United States)

    Zheng, Hao; Dong, Xiaoshe; Wang, Endong; Chen, Baoke; Zhu, Zhengdong; Liu, Chengzhe

    2015-01-01

    With the advantage of the reusability property of the virtualization technology, users can reuse various types and versions of existing operating systems and drivers in a virtual machine, so as to customize their application environment. In order to prevent users' virtualization environments being impacted by driver faults in virtual machine, Chariot examines the correctness of driver's write operations by the method of combining a driver's write operation capture and a driver's private access control table. However, this method needs to keep the write permission of shadow page table as read-only, so as to capture isolated driver's write operations through page faults, which adversely affect the performance of the driver. Based on delaying setting frequently used shadow pages' write permissions to read-only, this paper proposes an algorithm using shadow page cache to improve the performance of isolated drivers and carefully study the relationship between the performance of drivers and the size of shadow page cache. Experimental results show that, through the shadow page cache, the performance of isolated drivers can be greatly improved without impacting Chariot's reliability too much.

  10. Truck Drivers And Risk Of STDs Including HIV

    Directory of Open Access Journals (Sweden)

    Bansal R.K

    1995-01-01

    Full Text Available Research Question: Whether long distance truck drivers are at a higher risk of contracting and transmitting STDs including HIV? Objectives: i To study the degree of knowledge of HIV and AIDS among long- distance truck drivers. ii Assess their sexual behaviour including condom use. iii Explore their prevailing social influences and substance abuse patterns. iv Explore their treatment seeking bahaviour as regards STDs. v Deduce their risk of contracting and transmitting STDs including HIV. Study Design: Cross- sectional interview. Setting: Transport Nagar, Indore (M.P Participants: 210 senior drivers (First drivers and 210 junior drivers (Second drivers. Study Variables: Extra-Marital sexual intercourse, condom usage, past and present history of STDs, treatment and counseling, substance abuse, social â€" cultural milieu. Outcome Variables: Risk of contraction of STDs. Statistical Analysis: Univariate analysis. Results: 94% of the drivers were totally ignorant about AIDS. 82.9% and 43.8 % of the senior and junior drivers had a history of extra- marital sex and of these only 2 regularly used condoms. 13.8% and 3.3 % of the senior and junior drivers had a past or present history suggestive of STD infection. Alcohol and Opium were regularly used by them. Conclusion: The studied drivers are at a high risk of contracting and transmitting STDs including HIV.

  11. Drivers for animal welfare policies in Europe.

    Science.gov (United States)

    Dalla Villa, P; Matthews, L R; Alessandrini, B; Messori, S; Migliorati, G

    2014-04-01

    The European region has been, and remains, a global leader in the development of animal welfare policies. The region has a great diversity of cultures and religions, different levels of socio-economic development, and varied legislation, policies and practices. Nevertheless, there are common drivers for animal welfare policy based on a history of animal welfare ethics and obligations to animal users and society in general. A unifying goal of countries in the region is to achieve sustainable compliance with the World Organisation for Animal Health (OIE) standards on animal health and welfare. Ethics isthe overarching driver, supported by the actions of governmental, inter-governmental and non-governmental activities, markets and trade, science and knowledge. Historically, organisations involved in promoting animal welfare have tended to act in isolation. For example, non-governmental organisations (NGOs) have run campaigns to influence retailers and the welfare policies of their farmer suppliers. Increasingly, different organisations with common or complementary goals are working together. For example, competent authorities, inter-governmental bodies and NGOs have combined their efforts to address dog population control across several countries in the region. Also, animal welfare is becoming integrated into the corporate social responsibility targets of private companies. Science and knowledge, as drivers and tools, are assisting with the harmonisation of welfare standards, e.g. by providing a common basis for measuring welfare impacts through animal-based measures and widespread sharing of this information. Current trends suggest that there will be greater collaboration among the organisations driving change, and increasing convergence of animal welfare strategies and welfare assessment tools. The result will be increased harmonisation of animal welfare standards throughout the region.

  12. Global drivers, sustainable manufacturing and systems ergonomics.

    Science.gov (United States)

    Siemieniuch, C E; Sinclair, M A; Henshaw, M J deC

    2015-11-01

    This paper briefly explores the expected impact of the 'Global Drivers' (such as population demographics, food security; energy security; community security and safety), and the role of sustainability engineering in mitigating the potential effects of these Global Drivers. The message of the paper is that sustainability requires a significant input from Ergonomics/Human Factors, but the profession needs some expansion in its thinking in order to make this contribution. Creating a future sustainable world in which people experience an acceptable way of life will not happen without a large input from manufacturing industry into all the Global Drivers, both in delivering products that meet sustainability criteria (such as durability, reliability, minimised material requirement and low energy consumption), and in developing sustainable processes to deliver products for sustainability (such as minimum waste, minimum emissions and low energy consumption). Appropriate changes are already being implemented in manufacturing industry, including new business models, new jobs and new skills. Considerable high-level planning around the world is in progress and is bringing about these changes; for example, there is the US 'Advanced Manufacturing National Program' (AMNP)', the German 'Industrie 4.0' plan, the French plan 'la nouvelle France industrielle' and the UK Foresight publications on the 'Future of Manufacturing'. All of these activities recognise the central part that humans will continue to play in the new manufacturing paradigms; however, they do not discuss many of the issues that systems ergonomics professionals acknowledge. This paper discusses a number of these issues, highlighting the need for some new thinking and knowledge capture by systems ergonomics professionals. Among these are ethical issues, job content and skills issues. Towards the end, there is a summary of knowledge extensions considered necessary in order that systems ergonomists can be fully

  13. Rectangular waveform linear transformer driver module design

    International Nuclear Information System (INIS)

    Zhao Yue; Xie Weiping; Zhou Liangji; Chen Lin

    2014-01-01

    Linear Transformer Driver is a novel pulsed power technology, its main merits include a parallel LC discharge array and Inductive Voltage Adder. The parallel LC discharge array lowers the whole circuit equivalent inductance and the Inductive Voltage Adder unites the modules in series in order to create a high electric field grads, meanwhile, restricts the high voltage in a small space. The lower inductance in favor of LTD output a fast waveform and IVA confine high voltage in secondary cavity. In recently, some LTD-based pulsed power system has been development yet. The usual LTD architecture provides damped sine shaped output pulses that may not be suitable in flash radiography, high power microwave production, z-pinch drivers, and certain other applications. A more suitable driver output pulse would have a flat or inclined top (slightly rising or falling). In this paper, we present the design of an LTD cavity that generates this type of the output pulse by including within its circular array some number of the harmonic bricks in addition to the standard bricks according to Fourier progression theory. The parallel LC discharge array circuit formula is introduced by Kirchhoff Law, and the sum of harmonic is proofed as an analytic result, meanwhile, rationality of design is proved by simulation. Varying gas spark discharge dynamic resistance with harmonic order and switches jitter are analyzed. The results are as following: The more harmonic order is an approach to the ideal rectangular waveform, but lead to more system complexity. The capacity decreases as harmonic order increase, and gas spark discharge dynamic resistance rises with the capacity. The rising time protracts and flat is decay or even vanishes and the shot to shot reproducibility is degenerate as the switches jitter is high. (authors)

  14. Conscientious personality and young drivers' crash risk.

    Science.gov (United States)

    Ehsani, Johnathon P; Li, Kaigang; Simons-Morton, Bruce G; Fox Tree-McGrath, Cheyenne; Perlus, Jessamyn G; O'Brien, Fearghal; Klauer, Sheila G

    2015-09-01

    Personality characteristics are associated with many risk behaviors. However, the relationship between personality traits, risky driving behavior, and crash risk is poorly understood. The purpose of this study was to examine the association between personality, risky driving behavior, and crashes and near-crashes, using naturalistic driving research methods. Participants' driving exposure, kinematic risky driving (KRD), high-risk secondary task engagement, and the frequency of crashes and near-crashes (CNC) were assessed over the first 18months of licensure using naturalistic driving methods. A personality survey (NEO-Five Factor Inventory) was administered at baseline. The association between personality characteristics, KRD rate, secondary task engagement rate, and CNC rate was estimated using a linear regression model. Mediation analysis was conducted to examine if participants' KRD rate or secondary task engagement rate mediated the relationship between personality and CNC. Data were collected as part of the Naturalistic Teen Driving Study. Conscientiousness was marginally negatively associated with CNC (path c=-0.034, p=.09) and both potential mediators KRD (path a=-0.040, p=.09) and secondary task engagement while driving (path a=-0.053, p=.03). KRD, but not secondary task engagement, was found to mediate (path b=0.376, p=.02) the relationship between conscientiousness and CNC (path c'=-0.025, p=.20). Using objective measures of driving behavior and a widely used personality construct, these findings present a causal pathway through which personality and risky driving are associated with CNC. Specifically, more conscientious teenage drivers engaged in fewer risky driving maneuvers, and suffered fewer CNC. Part of the variability in crash risk observed among newly licensed teenage drivers can be explained by personality. Parents and driving instructors may take teenage drivers' personality into account when providing guidance, and establishing norms and

  15. Drivers of productivity in Vietnamese SMEs

    DEFF Research Database (Denmark)

    Calza, Elisa; Goedhuys, Micheline; Trifkovic, Neda

    2017-01-01

    Using a rich panel dataset of SMEs active in the manufacturing sector in Viet Nam, this paper investigates the drivers of firm productivity, focusing on the role played by international management standards certification. We develop and test the hypothesis that, controlling for technological...... international standards, the main findings show that the possession of an internationally recognized standard certificate leads to significant productivity premium. We further investigate the relationship between technological innovation and standard adoption. We find that the likelihood of certificate adoption...... is higher when firms implement technological innovations and that the effect of certification on productivity is particularly strong for firms with technological innovation....

  16. Drowsy Driver Detection via Steering Wheel

    Directory of Open Access Journals (Sweden)

    Herlina ABDUL RAHIM

    2010-09-01

    Full Text Available The main purpose of this project is to produce a safety system especially for fatigue car driver so as to prevent from accidents. The statistic on road fatality shows that human error constitute of 64.84 % road accidents fatality and 17.4 % due to technical factors. These systems encompassed the approach of hand pressure applied on the steering wheel. The steering will be installed with pressure sensors. At the same time these sensors can be used to measure gripping force while driving.

  17. Ludic interfaces. Driver and product of gamification

    Directory of Open Access Journals (Sweden)

    Mathias Fuchs

    2012-05-01

    Full Text Available The recent success of non-standard and playful interface devices like Wii Remote, Move, and Kinect is an indicator of a process that demonstrates that ludic interfaces might be the core driver for a transformation in the sector of video games cultures and beyond. Yet, ludic interfaces are drivers—as well as driven by social developments known as the ludification (Raessens, 2006; Fuchs & Strouhal, 2008, or the gamification of society (Schell, 2010; Bogost, 2010; Ionifides, 2011; Deterding, Khaled, Nacke, & Dixon, 2011.

  18. High current, high bandwidth laser diode current driver

    Science.gov (United States)

    Copeland, David J.; Zimmerman, Robert K., Jr.

    1991-01-01

    A laser diode current driver has been developed for free space laser communications. The driver provides 300 mA peak modulation current and exhibits an optical risetime of less than 400 ps. The current and optical pulses are well behaved and show minimal ringing. The driver is well suited for QPPM modulation at data rates up to 440 Mbit/s. Much previous work has championed current steering circuits; in contrast, the present driver is a single-ended on/off switch. This results in twice the power efficiency as a current steering driver. The driver electrical efficiency for QPPM data is 34 percent. The high speed switch is realized with a Ku-band GaAsFET transistor, with a suitable pre-drive circuit, on a hybrid microcircuit adjacent to the laser diode.

  19. Driver's mental workload prediction model based on physiological indices.

    Science.gov (United States)

    Yan, Shengyuan; Tran, Cong Chi; Wei, Yingying; Habiyaremye, Jean Luc

    2017-09-15

    Developing an early warning model to predict the driver's mental workload (MWL) is critical and helpful, especially for new or less experienced drivers. The present study aims to investigate the correlation between new drivers' MWL and their work performance, regarding the number of errors. Additionally, the group method of data handling is used to establish the driver's MWL predictive model based on subjective rating (NASA task load index [NASA-TLX]) and six physiological indices. The results indicate that the NASA-TLX and the number of errors are positively correlated, and the predictive model shows the validity of the proposed model with an R 2 value of 0.745. The proposed model is expected to provide a reference value for the new drivers of their MWL by providing the physiological indices, and the driving lesson plans can be proposed to sustain an appropriate MWL as well as improve the driver's work performance.

  20. Young Drivers Perceptual Learning Styles Preferences and Traffic Accidents

    Directory of Open Access Journals (Sweden)

    Svetlana Čičević

    2011-05-01

    Full Text Available Young drivers are over-represented in crash and fatality statistics. One way of dealing with this problem is to achieve primary prevention through driver education and training. Factors of traffic accidents related to gender, age, driving experience, and self-assessments of safety and their relationship to perceptual learning styles (LS preferences have been analyzed in this study. The results show that auditory is the most prominent LS. Drivers in general, as well as drivers without traffic accidents favour visual and tactile LS. Both inexperienced and highly experienced drivers show relatively high preference of kinaesthetic style. Yet, taking into account driving experience we could see that the role of kinaesthetic LS is reduced, since individual LS has become more important. Based on the results of this study it can be concluded that a multivariate and multistage approach to driver education, taking into account differences in LS preferences, would be highly beneficial for traffic safety.

  1. Real-time driver fatigue detection based on face alignment

    Science.gov (United States)

    Tao, Huanhuan; Zhang, Guiying; Zhao, Yong; Zhou, Yi

    2017-07-01

    The performance and robustness of fatigue detection largely decrease if the driver with glasses. To address this issue, this paper proposes a practical driver fatigue detection method based on face alignment at 3000 FPS algorithm. Firstly, the eye regions of the driver are localized by exploiting 6 landmarks surrounding each eye. Secondly, the HOG features of the extracted eye regions are calculated and put into SVM classifier to recognize the eye state. Finally, the value of PERCLOS is calculated to determine whether the driver is drowsy or not. An alarm will be generated if the eye is closed for a specified period of time. The accuracy and real-time on testing videos with different drivers demonstrate that the proposed algorithm is robust and obtain better accuracy for driver fatigue detection compared with some previous method.

  2. Peptic ulcer among urban bus drivers in Denmark

    DEFF Research Database (Denmark)

    Netterstrøm, Bo; Juel, K

    1990-01-01

    As part of a survey on the work environment of bus drivers, 2045 (83%) of 2465 male bus drivers in the three major cities in Denmark in 1978 answered a postal questionnaire on health and working conditions. In order to evaluate the relative occurrence of peptic ulcer among the bus drivers, a follow......-up study was also conducted. All hospital discharges with a peptic ulcer diagnosis among the bus drivers were registered from the Danish National Patient Register. All Danish men were used as reference group. On the basis of the 1978-questionnaire association between occupational and psychosocial factors...... and subsequent hospital discharge with a peptic ulcer diagnosis was studied. The prevalence of abdominal pain alleviated by food intake was 12% among bus drivers and 6% in the reference group. The incidence of hospital discharge with duodenal ulcer among younger bus drivers was twice the incidence among Danish...

  3. Solid state light source driver establishing buck or boost operation

    Science.gov (United States)

    Palmer, Fred

    2017-08-29

    A solid state light source driver circuit that operates in either a buck convertor or a boost convertor configuration is provided. The driver circuit includes a controller, a boost switch circuit and a buck switch circuit, each coupled to the controller, and a feedback circuit, coupled to the light source. The feedback circuit provides feedback to the controller, representing a DC output of the driver circuit. The controller controls the boost switch circuit and the buck switch circuit in response to the feedback signal, to regulate current to the light source. The controller places the driver circuit in its boost converter configuration when the DC output is less than a rectified AC voltage coupled to the driver circuit at an input node. The controller places the driver circuit in its buck converter configuration when the DC output is greater than the rectified AC voltage at the input node.

  4. Microcontroller based driver alertness detection systems to detect drowsiness

    Science.gov (United States)

    Adenin, Hasibah; Zahari, Rahimi; Lim, Tiong Hoo

    2018-04-01

    The advancement of embedded system for detecting and preventing drowsiness in a vehicle is a major challenge for road traffic accident systems. To prevent drowsiness while driving, it is necessary to have an alert system that can detect a decline in driver concentration and send a signal to the driver. Studies have shown that traffc accidents usually occur when the driver is distracted while driving. In this paper, we have reviewed a number of detection systems to monitor the concentration of a car driver and propose a portable Driver Alertness Detection System (DADS) to determine the level of concentration of the driver based on pixelated coloration detection technique using facial recognition. A portable camera will be placed at the front visor to capture facial expression and the eye activities. We evaluate DADS using 26 participants and have achieved 100% detection rate with good lighting condition and a low detection rate at night.

  5. Driver behaviour in motorway car-following transitions and driver support systems

    NARCIS (Netherlands)

    Feenstra, P.; Horst, A.R.A. van der

    2006-01-01

    Co-operative driving with speed adaptation functionality has great potential to improve traffic-throughput, traffic-safety, and environmental-impact on heavily used traffic-infrastructures. A driving-simulator study was performed to investigate the driver behaviour with respect to such

  6. Smart driver monitoring : when signal processing meets human factors : in the driver's seat

    NARCIS (Netherlands)

    Aghaei, A.S.; Donmez, B.; Liu, C.C.; He, D.; Liu, G.; Plataniotis, K.N.; Chen, H.Y.W.; Sojoudi, Z.

    2016-01-01

    This article provides an interdisciplinary perspective on driver monitoring systems by discussing state-of-the-art signal processing solutions in the context of road safety issues identified in human factors research. Recently, the human factors community has made significant progress in

  7. Driver support in congestion. An assessment of user needs and impacts on driver and traffic flow

    NARCIS (Netherlands)

    van Driel, Cornelie

    2007-01-01

    Mobility is a key factor for modern societies. However, it also brings about problems, such as congestion, accidents and pollution. High expectations rest on in-vehicle systems to contribute to solving these problems. These so-called driver support systems use advanced information and communication

  8. Hearing status among Norwegian train drivers and train conductors

    OpenAIRE

    Lie, A.; Skogstad, M.; Johnsen, T. S.; Engdahl, B.; Tambs, K.

    2013-01-01

    Background There is a general perception that train drivers and conductors may be at increased risk of developing noise-induced hearing loss. Aims To study job-related hearing loss among train drivers and train conductors. Methods Audiograms from train drivers and train conductors were obtained from the medical records of the occupational health service of the major Norwegian railway company. The results were compared with audiograms from an internal control group of railway workers and an ex...

  9. Processes, Performance Drivers and ICT Tools in Human Resources Management

    OpenAIRE

    Oškrdal Václav; Pavlíček Antonín; Jelínková Petra

    2011-01-01

    This article presents an insight to processes, performance drivers and ICT tools in human resources (HR) management area. On the basis of a modern approach to HR management, a set of business processes that are handled by today’s HR managers is defined. Consequently, the concept of ICT-supported performance drivers and their relevance in the area of HR management as well as the relationship between HR business processes, performance drivers and ICT tools are defined. The theoretical outcomes ...

  10. SSCL DD2 driver port and project update

    International Nuclear Information System (INIS)

    Mestad, S.L.

    1993-04-01

    A paper previously published in the 1992 ICHEP proceedings outlined the SSC's need for a high speed, high capacity tape drive to store detector data. Also described were stages and lessons learned while developing a custom device driver for the Ampex DD2 tape drive on a Silicon Graphics 4D/310. This paper updates the work on the SGI driver and describes the efforts in porting the driver to a Sun Microsystems 670 server

  11. SSCL DD2 driver port and project update

    International Nuclear Information System (INIS)

    Mestad, S.L.

    1994-01-01

    A paper previously published in the 1992 ICHEP proceedings outlined the SSC's need for a high speed, high capacity tape drive to store detector data. Also described were stages and lessons learned while developing a custom device driver for the Ampex DD2 tape drive on a Silicon Graphics 4D/310. This paper updates the work on the SGI driver and describes the efforts in porting the driver to a Sun Microsystems 670 server

  12. Improving drivers' knowledge of road rules using digital games.

    Science.gov (United States)

    Li, Qing; Tay, Richard

    2014-04-01

    Although a proficient knowledge of the road rules is important to safe driving, many drivers do not retain the knowledge acquired after they have obtained their licenses. Hence, more innovative and appealing methods are needed to improve drivers' knowledge of the road rules. This study examines the effect of game based learning on drivers' knowledge acquisition and retention. We find that playing an entertaining game that is designed to impart knowledge of the road rules not only improves players' knowledge but also helps them retain such knowledge. Hence, learning by gaming appears to be a promising learning approach for driver education. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Car drivers' perceptions of electronic stability control (ESC) systems.

    Science.gov (United States)

    Vadeby, Anna; Wiklund, Mats; Forward, Sonja

    2011-05-01

    As a way to reduce the number of car crashes different in-car safety devices are being introduced. In this paper one such application is being investigated, namely the electronic stability control system (ESC). The study used a survey method, including 2000 private car drivers (1000 driving a car with ESC and 1000 driving a car without ESC). The main objective was to investigate the effect of ESC on driver behaviour. Results show that drivers report that they drive even more carelessly when they believe that they have ESC, than when they do not. Men are more risk prone than women and young drivers more than older drivers. Using the theory of planned behaviour the results show that attitude, subjective norm and perceived control explain between 62% and 67% of driver's variation of intentions to take risks. When descriptive norm was added to the model a small but statistically significant increase was found. The study also shows that more than 35% erroneously believe that their car is equipped with an ESC system. These findings may suggest that driver behaviour could reduce the positive effect ESC has on accidents. It also shows that drivers who purchase a new car are not well informed about what kind of safety devices the car is equipped with. These findings highlight the need for more targeted information to drivers. Copyright © 2010 Elsevier Ltd. All rights reserved.

  14. Estimating likelihood of future crashes for crash-prone drivers

    OpenAIRE

    Subasish Das; Xiaoduan Sun; Fan Wang; Charles Leboeuf

    2015-01-01

    At-fault crash-prone drivers are usually considered as the high risk group for possible future incidents or crashes. In Louisiana, 34% of crashes are repeatedly committed by the at-fault crash-prone drivers who represent only 5% of the total licensed drivers in the state. This research has conducted an exploratory data analysis based on the driver faultiness and proneness. The objective of this study is to develop a crash prediction model to estimate the likelihood of future crashes for the a...

  15. Systems analysis for modular versus multi-beam HIF drivers

    International Nuclear Information System (INIS)

    Meier, W.R.; Logan, B.G.

    2004-01-01

    Previous modeling for HIF drivers concentrated on designs in which 100 or more beams are grouped in an array and accelerated through a common set of induction cores. The total beam energy required by the target is achieved by the combination of final ion energy, current per beam and number of beams. Economic scaling favors a large number of small (∼1 cm dia.) beams. An alternative architecture has now been investigated, which we refer to as a modular driver. In this case, the driver is subdivided into many (>10) independent accelerators with one or many beams each. A key objective of the modular driver approach is to be able to demonstrate all aspects of the driver (source-to-target) by building a single, lower cost module compared to a full-scale, multi-beam driver. We consider and compare several design options for the modular driver including single-beam designs with solenoid instead of quadrupole magnets in order to transport the required current per module in a single beam, solenoid/quad combinations, and multi-beam, all-quad designs. The drivers are designed to meet the requirements of the hybrid target, which can accommodate a larger spot size than the distributed radiator target that was used for the Robust Point Design. We compare the multi-beam and modular driver configuration for a variety and assumptions and identify key technology advances needed for the modular design

  16. Theoretical models of drivers behavior on the road

    Directory of Open Access Journals (Sweden)

    Marcin Piotr Biernacki

    2017-06-01

    Full Text Available Understanding of mechanisms and factors responsible for the driver behavior on the road is the subject of ongoing interest to transportation psychologists, occupational doctors and engineers. Models of driver behavior are a key point for the understanding the mechanisms and factors which may cause limitations to the optimal functioning on the road. They also systematize knowledge about the factors responsible for the behavior of the driver and thus constitute a starting point for formulating empirical or diagnostic hypotheses. The aim of this study is to present models of driver behavior from the descriptive and functional perspectives. Med Pr 2017;68(3:401–411

  17. 77 FR 10607 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

    Science.gov (United States)

    2012-02-22

    ...-2011-0367] Qualification of Drivers; Exemption Applications; Diabetes Mellitus AGENCY: Federal Motor... diabetes mellitus (ITDM) from operating commercial motor vehicles (CMVs) in interstate commerce. The...). [[Page 10608

  18. Testing a structural model of young driver willingness to uptake Smartphone Driver Support Systems.

    Science.gov (United States)

    Kervick, Aoife A; Hogan, Michael J; O'Hora, Denis; Sarma, Kiran M

    2015-10-01

    There is growing interest in the potential value of using phone applications that can monitor driver behaviour (Smartphone Driver Support Systems, 'SDSSs') in mitigating risky driving by young people. However, their value in this regard will only be realised if young people are willing to use this technology. This paper reports the findings of a study in which a novel structural model of willingness to use SDSSs was tested. Grounded in the driver monitoring and Technology Acceptance (TA) research literature, the model incorporates the perceived risks and gains associated with potential SDSS usage and additional social cognitive factors, including perceived usability and social influences. A total of 333 smartphone users, aged 18-24, with full Irish driving licenses completed an online questionnaire examining willingness or Behavioural Intention (BI) to uptake a SDSS. Following exploratory and confirmatory factor analyses, structural equation modelling indicated that perceived gains and social influence factors had significant direct effects on BI. Perceived risks and social influence also had significant indirect effects on BI, as mediated by perceived gains. Overall, this model accounted for 72.5% of the variance in willingness to uptake SDSSs. Multi-group structural models highlighted invariance of effects across gender, high and low risk drivers, and those likely or unlikely to adopt novel phone app technologies. These findings have implications for our understanding of the willingness of young drivers to adopt and use SDSSs, and highlight potential factors that could be targeted in behavioural change interventions seeking to improve usage rates. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Inertially confined fusion using heavy ion drivers

    International Nuclear Information System (INIS)

    Herrmannsfeldt, W.B.; Bangerter, R.O.; Bock, R.; Hogan, W.J.; Lindl, J.D.

    1991-10-01

    The various technical issues of HIF will be briefly reviewed in this paper. It will be seen that there are numerous areas in common in all the approaches to HIF. In the recent International Symposium on Heavy Ion Inertial Fusion, the attendees met in specialized workshop sessions to consider the needs for research in each area. Each of the workshop groups considered the key questions of this report: (1) Is this an appropriate time for international collaboration in HIF? (2) Which problems are most appropriate for such collaboration? (3) Can the sharing of target design information be set aside until other driver and systems issues are better resolved, by which time it might be supposed that there could be a relaxation of classification of target issues? (4) What form(s) of collaboration are most appropriate, e.g., bilateral or multilateral? (5) Can international collaboration be sensibly attempted without significant increases in funding for HIF? The authors of this report share the conviction that collaboration on a broad scale is mandatory for HIF to have the resources, both financial and personnel, to progress to a demonstration experiment. Ultimately it may be possible for a single driver with the energy, power, focusibility, and pulse shape to satisfy the needs of the international community for target physics research. Such a facility could service multiple experimental chambers with a variety of beam geometries and target concepts

  20. Convenience food products. Drivers for consumption.

    Science.gov (United States)

    Brunner, Thomas A; van der Horst, Klazine; Siegrist, Michael

    2010-12-01

    Convenience is one of the big trends in the food business. The demand for convenience food products is steadily increasing; therefore, understanding convenience food consumption is an important issue. Despite being vital properties of convenience food, saving time and effort have not been very successful constructs for predicting convenience food consumption. To examine a wide range of possible drivers for convenience food consumption, the present study uses a convenience food frequency questionnaire that asks about consumption behavior. A paper-and-pencil questionnaire was sent out to a representative sample of people in German-speaking Switzerland and yielded N = 918 complete datasets from persons mainly responsible for buying and preparing food in the household. The various convenience food products could be categorized into four groups, which we labeled as highly processed food items, moderately processed food items, single components, and salads. Fifteen drivers were found to have a significant impact either on total convenience consumption or on one of the identified categories. Strong predictors were age, concern about naturalness, nutrition knowledge, and cooking skills. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Induction linac drivers: Prospects for the future

    International Nuclear Information System (INIS)

    Keefe, D.

    1989-01-01

    This review is intended to place in perspective our current view of the parameter ranges for induction linac drivers that lead to attractive scenarios for civilian electrical power plants; there is a surprising degree of choice (a factor of 2 or so in most parameters) before any significant impact on the cost of energy results. The progress and goals of the US heavy-ion fusion accelerator research (HIFAR) program are reviewed. The step between the realization of the HIFAR goals and a full-scale driver is seen to be very large indeed and will require one or more significant intermediate steps which can be justified only by a commitment to advance the HIF method towards a true fusion goal. Historial anomalies in the way that fusion programs for both military and civilian applications are administered will need to be resolved; the absence of any presently perceived energy crisis results in little current sense of urgency to develop vigorous long-term energy solutions. (orig.)

  2. Experiments and prospects for induction linac drivers

    International Nuclear Information System (INIS)

    Keefe, D.

    1986-05-01

    In the last three years, the US program in Heavy Ion Fusion has concentrated on understanding the induction linac approach to a power-plant driver. In this method it is important that the beam current be maximized throughout the accelerator. Consequently, it is crucial to understand the space-charge limit in the AG transport system in the linac and, also, to achieve current amplification during acceleration to keep pace with the kinematical increase of this limit with energy. Experimental results on both these matters and also on the use of multiple beams (inside the same accelerating structure) will be described. A new examination of the most attractive properties of the induction linac for a fusion driver has clearly pointed to the advantage of using heavy ions with a charge-state greater than unity - perhaps q = 3 may be an optimum. This development places even greater importance on understanding space-charge limits and mechanisms for emittance growth; also, it will require a new emphasis on the development of a suitable ion source

  3. Drivers of Pontocaspian Biodiversity Rise and Demise

    Science.gov (United States)

    Wesselingh, Frank; Flecker, Rachel; Wilke, Thomas; Leroy, Suzanne; Krijgsman, Wout; Stoica, Marius

    2015-04-01

    In the past two million years, the region of the Black Sea Basin, Caspian Basin and adjacent Anatolia and the Balkans were the stage of the evolution of a unique brackish water fauna, the so-called Pontocaspian fauna. The fauna is the result of assembly of genera with a Paratethyan origin and Anatolian origins during the Early Pleistocene. The rapid diversification of the Pontocaspian fauna is the result of the very dynamic nature of the lakes (the Caspian Sea is technically a lake) and seas in the region in the past two million years. In most times the various lake basins were isolated (like today), but in other episodes connections existed. Regional and global climate as well as the regional tectonic regimes were main drivers of lake basin evolution. Over the past 80 years a major biodiversity crisis is hitting the Pontocaspian faunas due to environmental degradation, pollution and invasive species. In the new EU-ETN PRIDE (Drivers of Pontocaspian Biodiversity Rise and Demise)we will be documenting the geological context of past diversifications and turnover events. We present examples of rapid turnover (biodiversity crises) in the Quaternary, assess driving forces and draw implications for the nature of the current human-mediated biodiversity crisis in the region.

  4. Induction linac drivers: Prospects for the future

    International Nuclear Information System (INIS)

    Keefe, D.

    1988-06-01

    This review is intended to place in perspective our current view of the parameter ranges for induction linac drivers that lead to attractive scenarios for civilian electrical power plants; there is a surprising degree of choice (a factor of two or so in most parameters) before any significant impact on the cost of energy results. The progress and goals of the US Heavy Ion Accelerator Research (HIFAR) program are reviewed. The step between the realization of the HIFAR goals and a full-scale driver is seen to be very large indeed and will require one or more significant intermediate steps which can be justified only by a commitment to advance the HIF method towards a true fusion goal. Historical anomalies in the way that fusion programs for both military and civilian applications are administered will need to be resolved; the absence of any presently perceived energy crisis results in little current sense of urgency to develop vigorous long-term energy solutions. 12 refs., 3 figs., 1 tab

  5. Experiments and prospects for induction linac drivers

    International Nuclear Information System (INIS)

    Keefe, D.

    1986-12-01

    In the last three years, the US program in Heavy Ion Fusion has concentrated on understanding the induction linac approach to a power-plant driver. In this method it is important that the beam current be maximized throughout the accelerator. Consequently, it is crucial to understand the space-charge limit in the AG transport system in the linac and, also, to achieve current amplification during acceleration to keep pace with the kinematical increase of this limit with energy. Experimental results on both these matters and also on the use of multiple beams (inside the same accelerating structure) will be described. A new examination of the most attractive properties of the induction linac for a fusion driver has clearly pointed to the advantage of using heavy ions with a charge-state greater than unity - perhaps q = 3 may be an optimum. This development places even greater importance on understanding space-charge limits and mechanisms for emittance growth; also, it will require a new emphasis on the development of a suitable ion source

  6. Cognitive compatibility of motorcyclists and car drivers.

    Science.gov (United States)

    Walker, Guy H; Stanton, Neville A; Salmon, Paul M

    2011-05-01

    Incompatibility between different types of road user is a problem that previous research has shown to be resistant to a range of interventions. Cars and motorcycles are particularly prone to this. Insight is provided in this paper by a naturalistic method using concurrent verbal protocols and an automatic, highly reliable semantic network creation tool. The method shows how the same road situation is interpreted differently by car drivers and motorcyclists in ways congruent with wider accident rates. Analysis of the structure and content of the semantic networks reveals a greater degree of cognitive compatibility on faster roads such as motorways, but evidence of more critical incompatibilities on country roads and junctions. Both of these road types are implicated in helping to activate cognitive schema which in turn generate stereotypical behaviors unfavourable to the anticipation of motorcyclists by car drivers. The results are discussed in terms of practical measures such as road signs which warn of events behind as well as in front, cross-mode training and the concept of route driveability. Copyright © 2010 Elsevier Ltd. All rights reserved.

  7. Lifestyle and accidents among young drivers.

    Science.gov (United States)

    Gregersen, N P; Berg, H Y

    1994-06-01

    This study covers the lifestyle component of the problems related to young drivers' accident risk. The purpose of the study is to measure the relationship between lifestyle and accident risk, and to identify specific high-risk and low-risk groups. Lifestyle is measured through a questionnaire, where 20-year-olds describe themselves and how often they deal with a large number of different activities, like sports, music, movies, reading, cars and driving, political engagement, etc. They also report their involvement in traffic accidents. With a principal component analysis followed by a cluster analysis, lifestyle profiles are defined. These profiles are finally correlated to accidents, which makes it possible to define high-risk and low-risk groups. The cluster analysis defined 15 clusters including four high-risk groups with an average overrisk of 150% and two low-risk groups with an average underrisk of 75%. The results are discussed from two perspectives. The first is the importance of theoretical understanding of the contribution of lifestyle factors to young drivers' high accident risk. The second is how the findings could be used in practical road safety measures, like education, campaigns, etc.

  8. Data and methods for studying commercial motor vehicle driver fatigue, highway safety and long-term driver health.

    Science.gov (United States)

    Stern, Hal S; Blower, Daniel; Cohen, Michael L; Czeisler, Charles A; Dinges, David F; Greenhouse, Joel B; Guo, Feng; Hanowski, Richard J; Hartenbaum, Natalie P; Krueger, Gerald P; Mallis, Melissa M; Pain, Richard F; Rizzo, Matthew; Sinha, Esha; Small, Dylan S; Stuart, Elizabeth A; Wegman, David H

    2018-03-09

    This article summarizes the recommendations on data and methodology issues for studying commercial motor vehicle driver fatigue of a National Academies of Sciences, Engineering, and Medicine study. A framework is provided that identifies the various factors affecting driver fatigue and relating driver fatigue to crash risk and long-term driver health. The relevant factors include characteristics of the driver, vehicle, carrier and environment. Limitations of existing data are considered and potential sources of additional data described. Statistical methods that can be used to improve understanding of the relevant relationships from observational data are also described. The recommendations for enhanced data collection and the use of modern statistical methods for causal inference have the potential to enhance our understanding of the relationship of fatigue to highway safety and to long-term driver health. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  9. Dynamic Characteristics of DC Servo Motor Driven by Conventional Servo Driver: Estimation of Circuit Constants in Conventional Servo Driver

    OpenAIRE

    酒井, 史敏; 神谷, 好承; 関, 啓明; 疋津, 正利

    2000-01-01

    DC servo motors that are made as manufactured goods in the factory are widely used as actuators for driving many automatic machines. Then the manufactured driver (amplifier) that is matched to its servo motor is coveniently chosen to drive when aiming at high performance of the motion control. Motion of motor that is driven by the manufactured servo driver has very complicated dynamic characteristics. In this study, it is tried to make clear about inner composition of the servo driver through...

  10. In-reactor cladding breach of EBR-II driver-fuel elements

    International Nuclear Information System (INIS)

    Seidel, B.R.; Einziger, R.E.

    1977-01-01

    Knowledge of performance and minimum useful element lifetime of Mark-II driver-fuel elements is required to maintain a high plant operating capacity factor with maximum fuel utilization. To obtain such knowledge, intentional cladding breach has been obtained in four run-to-cladding-breach Mark-II experimental driver-fuel subassemblies operating under normal conditions in EBR-II. Breach and subsequent fission-product release proved benign to reactor operations. The breaches originated on the outer surface of the cladding in the root of the restrainer dimples and were intergranular. The Weibull distribution of lifetime accurately predicts the observed minimum useful element lifetime of 10 at.% burnup, with breach ensuing shortly thereafter

  11. Sensorimotor and postural control factors associated with driving safety in a community-dwelling older driver population.

    Science.gov (United States)

    Lacherez, Philippe; Wood, Joanne M; Anstey, Kaarin J; Lord, Stephen R

    2014-02-01

    To establish whether sensorimotor function and balance are associated with on-road driving performance in older adults. The performance of 270 community-living adults aged 70-88 years recruited via the electoral roll was measured on a battery of peripheral sensation, strength, flexibility, reaction time, and balance tests and on a standardized measure of on-road driving performance. Forty-seven participants (17.4%) were classified as unsafe based on their driving assessment. Unsafe driving was associated with reduced peripheral sensation, lower limb weakness, reduced neck range of motion, slow reaction time, and poor balance in univariate analyses. Multivariate logistic regression analysis identified poor vibration sensitivity, reduced quadriceps strength, and increased sway on a foam surface with eyes closed as significant and independent risk factors for unsafe driving. These variables classified participants into safe and unsafe drivers with a sensitivity of 74% and specificity of 70%. A number of sensorimotor and balance measures were associated with driver safety and the multivariate model comprising measures of sensation, strength, and balance was highly predictive of unsafe driving in this sample. These findings highlight important determinants of driver safety and may assist in developing efficacious driver safety strategies for older drivers.

  12. Illinois School Bus Driver Instructional Program. Trainee Guide. Revised.

    Science.gov (United States)

    Illinois State Board of Education, Springfield.

    This trainee guide contains six units of materials for use by those studying to become school bus drivers in the State of Illinois. Covered in the units are the following topics: school bus driver role and responsibility, passenger control, first aid, driving fundamentals, accidents and emergencies, and detecting hazards. Each unit contains a…

  13. 49 CFR 383.51 - Disqualification of drivers.

    Science.gov (United States)

    2010-10-01

    ... parking violation) arising in connection with a fatal accident 60 days 60 days 120 days 120 days. (6... less than 120 days No less than 1 year. (4) The driver fails to have sufficient space to drive... driver fails to negotiate a crossing because of insufficient undercarriage clearance * * * No less than...

  14. The role of simulation in the assessment of older drivers.

    NARCIS (Netherlands)

    Sommer, Sascha; Rothermel, Stefan; Henriksson, Per; de Waard, Dick; Brookhuis, Karel; Sommer, Sascha; Verwey, Willem B.

    2003-01-01

    Within the project AGILE an assessment system for ageing drivers is developed. A multi-tier procedure including simulator-based diagnostic tests is will be created. Objective driver performance measurement, design of risky scenarios to test performance limits and high face validity are benefits of

  15. Analyzing the drivers of green manufacturing with fuzzy approach

    DEFF Research Database (Denmark)

    Govindan, Kannan; Diabat, Ali; Madan Shankar, K.

    2015-01-01

    India, and aided by their replies; a pair-wise comparison was made among the drivers. The pair-wise comparison is used as an input data and the drivers were analyzed on its basis. The analysis resorted to the use of a fuzzy Multi Criteria Decision Making (MCDM) approach. The obtained results...

  16. Matching Countermeasures to Driver Types and Speeding Behavior : Traffic Tech

    Science.gov (United States)

    2017-06-01

    Speeding is a common behavior; most drivers exceed the speed limit some of the time. It is also a complicated behavior that varies by driver and situation. Speeding-related crashes take a large annual toll in injuries, lost lives, and high economic c...

  17. 49 CFR 391.11 - General qualifications of drivers.

    Science.gov (United States)

    2010-10-01

    ... understand highway traffic signs and signals in the English language, to respond to official inquiries, and... QUALIFICATIONS OF DRIVERS AND LONGER COMBINATION VEHICLE (LCV) DRIVER INSTRUCTORS Qualification and... motor vehicle unless he/she is qualified to drive a commercial motor vehicle. Except as provided in...

  18. 75 FR 47886 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2010-08-09

    ... greater level of safety is likely to be achieved by permitting each of these drivers to drive in... performance is especially important in evaluating future safety, according to several research studies... the drivers was involved in a crash. All the applicants achieved a record of safety while driving with...

  19. 76 FR 5324 - Hours of Service of Drivers

    Science.gov (United States)

    2011-01-31

    ... and how frequently the 11th hour is used. It seeks data on how much of the 11th hour is used when a... soliciting information on patterns of work for night drivers: 2a. For drivers who always drive at night, what... Act restrictions which prohibit Agency officials from engaging in policy discussions about open...

  20. Comprehensive Characterization of Cancer Driver Genes and Mutations

    NARCIS (Netherlands)

    Bailey, Matthew H.; Tokheim, Collin; Porta-Pardo, Eduard; Sengupta, Sohini; Bertrand, Denis; Weerasinghe, Amila; Colaprico, Antonio; Wendl, Michael C.; Kim, Jaegil; Reardon, Brendan; Ng, Patrick Kwok Shing; Jeong, Kang Jin; Cao, Song; Wang, Zixing; Gao, Jianjiong; Gao, Qingsong; Wang, Fang; Liu, Eric Minwei; Mularoni, Loris; Rubio-Perez, Carlota; Nagarajan, Niranjan; Cortés-Ciriano, Isidro; Zhou, Daniel Cui; Liang, Wen Wei; Hess, Julian M.; Yellapantula, Venkata D.; Tamborero, David; Gonzalez-Perez, Abel; Suphavilai, Chayaporn; Ko, Jia Yu; Khurana, Ekta; Park, Peter J.; Van Allen, Eliezer M.; Liang, Han; Caesar-Johnson, Samantha J.; Demchok, John A.; Felau, Ina; Kasapi, Melpomeni; Ferguson, Martin L.; Hutter, Carolyn M.; Sofia, Heidi J.; Tarnuzzer, Roy; Wang, Zhining; Yang, Liming; Zenklusen, Jean C.; Zhang, Jiashan (Julia); Chudamani, Sudha; Liu, Jia; Lolla, Laxmi; Naresh, Rashi; Pihl, Todd; Sun, Qiang; Wan, Yunhu; Wu, Ye; Cho, Juok; DeFreitas, Timothy; Frazer, Scott; Gehlenborg, Nils; Getz, Gad; Heiman, David I.; Kim, Jaegil; Lawrence, Michael S.; Lin, Pei; Meier, Sam; Noble, Michael S.; Saksena, Gordon; Voet, Doug; Zhang, Hailei; Bernard, Brady; Chambwe, Nyasha; Dhankani, Varsha; Knijnenburg, Theo; Kramer, Roger; Leinonen, Kalle; Liu, Yuexin; Miller, Michael; Reynolds, Sheila; Shmulevich, Ilya; Thorsson, Vesteinn; Zhang, Wei; Akbani, Rehan; Broom, Bradley M.; Hegde, Apurva M.; Ju, Zhenlin; Kanchi, Rupa S.; Korkut, Anil; Li, Jun; Liang, Han; Ling, Shiyun; Liu, Wenbin; Lu, Yiling; Mills, Gordon B.; Ng, Kwok Shing; Rao, Arvind; Ryan, Michael; Wang, Jing; Weinstein, John N.; Zhang, Jiexin; Abeshouse, Adam; Armenia, Joshua; Chakravarty, Debyani; Chatila, Walid K.; de Bruijn, Ino; Gao, Jianjiong; Gross, Benjamin E.; Heins, Zachary J.; Kundra, Ritika; La, Konnor; Ladanyi, Marc; Luna, Augustin; Nissan, Moriah G.; Ochoa, Angelica; Phillips, Sarah M.; Reznik, Ed; Sanchez-Vega, Francisco; Sander, Chris; Schultz, Nikolaus; Sheridan, Robert; Sumer, S. Onur; Sun, Yichao; Taylor, Barry S.; Wang, Jioajiao; Zhang, Hongxin; Anur, Pavana; Peto, Myron; Spellman, Paul; Benz, Christopher; Stuart, Joshua M.; Wong, Christopher K.; Yau, Christina; Hayes, D. Neil; Parker, Joel S.; Wilkerson, Matthew D.; Ally, Adrian; Balasundaram, Miruna; Bowlby, Reanne; Brooks, Denise; Carlsen, Rebecca; Chuah, Eric; Dhalla, Noreen; Holt, Robert; Jones, Steven J.M.; Kasaian, Katayoon; Lee, Darlene; Ma, Yussanne; Marra, Marco A.; Mayo, Michael; Moore, Richard A.; Mungall, Andrew J.; Mungall, Karen; Robertson, A. Gordon; Sadeghi, Sara; Schein, Jacqueline E.; Sipahimalani, Payal; Tam, Angela; Thiessen, Nina; Tse, Kane; Wong, Tina; Berger, Ashton C.; Beroukhim, Rameen; Cherniack, Andrew D.; Cibulskis, Carrie; Gabriel, Stacey B.; Gao, Galen F.; Ha, Gavin; Meyerson, Matthew; Schumacher, Steven E.; Shih, Juliann; Kucherlapati, Melanie H.; Kucherlapati, Raju S.; Baylin, Stephen; Cope, Leslie; Danilova, Ludmila; Bootwalla, Moiz S.; Lai, Phillip H.; Maglinte, Dennis T.; Van Den Berg, David J.; Weisenberger, Daniel J.; Auman, J. Todd; Balu, Saianand; Bodenheimer, Tom; Fan, Cheng; Hoadley, Katherine A.; Hoyle, Alan P.; Jefferys, Stuart R.; Jones, Corbin D.; Meng, Shaowu; Mieczkowski, Piotr A.; Mose, Lisle E.; Perou, Amy H.; Perou, Charles M.; Roach, Jeffrey; Shi, Yan; Simons, Janae V.; Skelly, Tara; Soloway, Matthew G.; Tan, Donghui; Veluvolu, Umadevi; Fan, Huihui; Hinoue, Toshinori; Laird, Peter W.; Shen, Hui; Zhou, Wanding; Bellair, Michelle; Chang, Kyle; Covington, Kyle; Creighton, Chad J.; Dinh, Huyen; Doddapaneni, Harsha Vardhan; Donehower, Lawrence A.; Drummond, Jennifer; Gibbs, Richard A.; Glenn, Robert; Hale, Walker; Han, Yi; Hu, Jianhong; Korchina, Viktoriya; Lee, Sandra; Lewis, Lora; Li, Wei; Liu, Xiuping; Morgan, Margaret; Morton, Donna; Muzny, Donna; Santibanez, Jireh; Sheth, Margi; Shinbrot, Eve; Wang, Linghua; Wang, Min; Wheeler, David; Xi, Liu; Zhao, Fengmei; Hess, Julian; Appelbaum, Elizabeth L.; Bailey, Matthew; Cordes, Matthew G.; Ding, Li; Fronick, Catrina C.; Fulton, Lucinda A.; Fulton, Robert S.; Kandoth, Cyriac; Mardis, Elaine R.; McLellan, Michael D.; Miller, Christopher A.; Schmidt, Heather K.; Wilson, Richard K.; Crain, Daniel; Curley, Erin; Gardner, Johanna; Lau, Kevin; Mallery, David; Morris, Scott; Paulauskis, Joseph; Penny, Robert; Shelton, Candace; Shelton, Troy; Sherman, Mark; Thompson, Eric; Yena, Peggy; Bowen, Jay; Gastier-Foster, Julie M.; Gerken, Mark; Leraas, Kristen M.; Lichtenberg, Tara M.; Ramirez, Nilsa C.; Wise, Lisa; Zmuda, Erik; Corcoran, Niall; Costello, Tony; Hovens, Christopher; Carvalho, Andre L.; de Carvalho, Ana C.; Fregnani, José H.; Longatto-Filho, Adhemar; Reis, Rui M.; Scapulatempo-Neto, Cristovam; Silveira, Henrique C.S.; Vidal, Daniel O.; Burnette, Andrew; Eschbacher, Jennifer; Hermes, Beth; Noss, Ardene; Singh, Rosy; Anderson, Matthew L.; Castro, Patricia D.; Ittmann, Michael; Huntsman, David; Kohl, Bernard; Le, Xuan; Thorp, Richard; Andry, Chris; Duffy, Elizabeth R.; Lyadov, Vladimir; Paklina, Oxana; Setdikova, Galiya; Shabunin, Alexey; Tavobilov, Mikhail; McPherson, Christopher; Warnick, Ronald; Berkowitz, Ross; Cramer, Daniel; Feltmate, Colleen; Horowitz, Neil; Kibel, Adam; Muto, Michael; Raut, Chandrajit P.; Malykh, Andrei; Barnholtz-Sloan, Jill S.; Barrett, Wendi; Devine, Karen; Fulop, Jordonna; Ostrom, Quinn T.; Shimmel, Kristen; Wolinsky, Yingli; Sloan, Andrew E.; De Rose, Agostino; Giuliante, Felice; Goodman, Marc; Karlan, Beth Y.; Hagedorn, Curt H.; Eckman, John; Harr, Jodi; Myers, Jerome; Tucker, Kelinda; Zach, Leigh Anne; Deyarmin, Brenda; Hu, Hai; Kvecher, Leonid; Larson, Caroline; Mural, Richard J.; Somiari, Stella; Vicha, Ales; Zelinka, Tomas; Bennett, Joseph; Iacocca, Mary; Rabeno, Brenda; Swanson, Patricia; Latour, Mathieu; Lacombe, Louis; Têtu, Bernard; Bergeron, Alain; McGraw, Mary; Staugaitis, Susan M.; Chabot, John; Hibshoosh, Hanina; Sepulveda, Antonia; Su, Tao; Wang, Timothy; Potapova, Olga; Voronina, Olga; Desjardins, Laurence; Mariani, Odette; Roman-Roman, Sergio; Sastre, Xavier; Stern, Marc Henri; Cheng, Feixiong; Signoretti, Sabina; Berchuck, Andrew; Bigner, Darell; Lipp, Eric; Marks, Jeffrey; McCall, Shannon; McLendon, Roger; Secord, Angeles; Sharp, Alexis; Behera, Madhusmita; Brat, Daniel J.; Chen, Amy; Delman, Keith; Force, Seth; Khuri, Fadlo; Magliocca, Kelly; Maithel, Shishir; Olson, Jeffrey J.; Owonikoko, Taofeek; Pickens, Alan; Ramalingam, Suresh; Shin, Dong M.; Sica, Gabriel; Van Meir, Erwin G.; Zhang, Hongzheng; Eijckenboom, Wil; Gillis, Ad; Korpershoek, Esther; Looijenga, Leendert; Oosterhuis, Wolter; Stoop, Hans; van Kessel, Kim E.; Zwarthoff, Ellen C.; Calatozzolo, Chiara; Cuppini, Lucia; Cuzzubbo, Stefania; DiMeco, Francesco; Finocchiaro, Gaetano; Mattei, Luca; Perin, Alessandro; Pollo, Bianca; Chen, Chu; Houck, John; Lohavanichbutr, Pawadee; Hartmann, Arndt; Stoehr, Christine; Stoehr, Robert; Taubert, Helge; Wach, Sven; Wullich, Bernd; Kycler, Witold; Murawa, Dawid; Wiznerowicz, Maciej; Chung, Ki; Edenfield, W. Jeffrey; Martin, Julie; Baudin, Eric; Bubley, Glenn; Bueno, Raphael; De Rienzo, Assunta; Richards, William G.; Kalkanis, Steven; Mikkelsen, Tom; Noushmehr, Houtan; Scarpace, Lisa; Girard, Nicolas; Aymerich, Marta; Campo, Elias; Giné, Eva; Guillermo, Armando López; Van Bang, Nguyen; Hanh, Phan Thi; Phu, Bui Duc; Tang, Yufang; Colman, Howard; Evason, Kimberley; Dottino, Peter R.; Martignetti, John A.; Gabra, Hani; Juhl, Hartmut; Akeredolu, Teniola; Stepa, Serghei; Hoon, Dave; Ahn, Keunsoo; Kang, Koo Jeong; Beuschlein, Felix; Breggia, Anne; Birrer, Michael; Bell, Debra; Borad, Mitesh; Bryce, Alan H.; Castle, Erik; Chandan, Vishal; Cheville, John; Copland, John A.; Farnell, Michael; Flotte, Thomas; Giama, Nasra; Ho, Thai; Kendrick, Michael; Kocher, Jean Pierre; Kopp, Karla; Moser, Catherine; Nagorney, David; O'Brien, Daniel; O'Neill, Brian Patrick; Patel, Tushar; Petersen, Gloria; Que, Florencia; Rivera, Michael; Roberts, Lewis; Smallridge, Robert; Smyrk, Thomas; Stanton, Melissa; Thompson, R. Houston; Torbenson, Michael; Yang, Ju Dong; Zhang, Lizhi; Brimo, Fadi; Ajani, Jaffer A.; Gonzalez, Ana Maria Angulo; Behrens, Carmen; Bondaruk, Jolanta; Broaddus, Russell; Czerniak, Bogdan; Esmaeli, Bita; Fujimoto, Junya; Gershenwald, Jeffrey; Guo, Charles; Lazar, Alexander J.; Logothetis, Christopher; Meric-Bernstam, Funda; Moran, Cesar; Ramondetta, Lois; Rice, David; Sood, Anil; Tamboli, Pheroze; Thompson, Timothy; Troncoso, Patricia; Tsao, Anne; Wistuba, Ignacio; Carter, Candace; Haydu, Lauren; Hersey, Peter; Jakrot, Valerie; Kakavand, Hojabr; Kefford, Richard; Lee, Kenneth; Long, Georgina; Mann, Graham; Quinn, Michael; Saw, Robyn; Scolyer, Richard; Shannon, Kerwin; Spillane, Andrew; Stretch, Jonathan; Synott, Maria; Thompson, John; Wilmott, James; Al-Ahmadie, Hikmat; Chan, Timothy A.; Ghossein, Ronald; Gopalan, Anuradha; Levine, Douglas A.; Reuter, Victor; Singer, Samuel; Singh, Bhuvanesh; Tien, Nguyen Viet; Broudy, Thomas; Mirsaidi, Cyrus; Nair, Praveen; Drwiega, Paul; Miller, Judy; Smith, Jennifer; Zaren, Howard; Park, Joong Won; Hung, Nguyen Phi; Kebebew, Electron; Linehan, W. Marston; Metwalli, Adam R.; Pacak, Karel; Pinto, Peter A.; Schiffman, Mark; Schmidt, Laura S.; Vocke, Cathy D.; Wentzensen, Nicolas; Worrell, Robert; Yang, Hannah; Moncrieff, Marc; Goparaju, Chandra; Melamed, Jonathan; Pass, Harvey; Botnariuc, Natalia; Caraman, Irina; Cernat, Mircea; Chemencedji, Inga; Clipca, Adrian; Doruc, Serghei; Gorincioi, Ghenadie; Mura, Sergiu; Pirtac, Maria; Stancul, Irina; Tcaciuc, Diana; Albert, Monique; Alexopoulou, Iakovina; Arnaout, Angel; Bartlett, John; Engel, Jay; Gilbert, Sebastien; Parfitt, Jeremy; Sekhon, Harman; Thomas, George; Rassl, Doris M.; Rintoul, Robert C.; Bifulco, Carlo; Tamakawa, Raina; Urba, Walter; Hayward, Nicholas; Timmers, Henri; Antenucci, Anna; Facciolo, Francesco; Grazi, Gianluca; Marino, Mirella; Merola, Roberta; de Krijger, Ronald; Gimenez-Roqueplo, Anne Paule; Piché, Alain; Chevalier, Simone; McKercher, Ginette; Birsoy, Kivanc; Barnett, Gene; Brewer, Cathy; Farver, Carol; Naska, Theresa; Pennell, Nathan A.; Raymond, Daniel; Schilero, Cathy; Smolenski, Kathy; Williams, Felicia; Morrison, Carl; Borgia, Jeffrey A.; Liptay, Michael J.; Pool, Mark; Seder, Christopher W.; Junker, Kerstin; Omberg, Larsson; Dinkin, Mikhail; Manikhas, George; Alvaro, Domenico; Bragazzi, Maria Consiglia; Cardinale, Vincenzo; Carpino, Guido; Gaudio, Eugenio; Chesla, David; Cottingham, Sandra; Dubina, Michael; Moiseenko, Fedor; Dhanasekaran, Renumathy; Becker, Karl Friedrich; Janssen, Klaus Peter; Slotta-Huspenina, Julia; Abdel-Rahman, Mohamed H.; Aziz, Dina; Bell, Sue; Cebulla, Colleen M.; Davis, Amy; Duell, Rebecca; Elder, J. Bradley; Hilty, Joe; Kumar, Bahavna; Lang, James; Lehman, Norman L.; Mandt, Randy; Nguyen, Phuong; Pilarski, Robert; Rai, Karan; Schoenfield, Lynn; Senecal, Kelly; Wakely, Paul; Hansen, Paul; Lechan, Ronald; Powers, James; Tischler, Arthur; Grizzle, William E.; Sexton, Katherine C.; Kastl, Alison; Henderson, Joel; Porten, Sima; Waldmann, Jens; Fassnacht, Martin; Asa, Sylvia L.; Schadendorf, Dirk; Couce, Marta; Graefen, Markus; Huland, Hartwig; Sauter, Guido; Schlomm, Thorsten; Simon, Ronald; Tennstedt, Pierre; Olabode, Oluwole; Nelson, Mark; Bathe, Oliver; Carroll, Peter R.; Chan, June M.; Disaia, Philip; Glenn, Pat; Kelley, Robin K.; Landen, Charles N.; Phillips, Joanna; Prados, Michael; Simko, Jeffry; Smith-McCune, Karen; VandenBerg, Scott; Roggin, Kevin; Fehrenbach, Ashley; Kendler, Ady; Sifri, Suzanne; Steele, Ruth; Jimeno, Antonio; Carey, Francis; Forgie, Ian; Mannelli, Massimo; Carney, Michael; Hernandez, Brenda; Campos, Benito; Herold-Mende, Christel; Jungk, Christin; Unterberg, Andreas; von Deimling, Andreas; Bossler, Aaron; Galbraith, Joseph; Jacobus, Laura; Knudson, Michael; Knutson, Tina; Ma, Deqin; Milhem, Mohammed; Sigmund, Rita; Godwin, Andrew K.; Madan, Rashna; Rosenthal, Howard G.; Adebamowo, Clement; Adebamowo, Sally N.; Boussioutas, Alex; Beer, David; Giordano, Thomas; Mes-Masson, Anne Marie; Saad, Fred; Bocklage, Therese; Landrum, Lisa; Mannel, Robert; Moore, Kathleen; Moxley, Katherine; Postier, Russel; Walker, Joan; Zuna, Rosemary; Feldman, Michael; Valdivieso, Federico; Dhir, Rajiv; Luketich, James; Pinero, Edna M.Mora; Quintero-Aguilo, Mario; Carlotti, Carlos Gilberto; Dos Santos, Jose Sebastião; Kemp, Rafael; Sankarankuty, Ajith; Tirapelli, Daniela; Catto, James; Agnew, Kathy; Swisher, Elizabeth; Creaney, Jenette; Robinson, Bruce; Shelley, Carl Simon; Godwin, Eryn M.; Kendall, Sara; Shipman, Cassaundra; Bradford, Carol; Carey, Thomas; Haddad, Andrea; Moyer, Jeffey; Peterson, Lisa; Prince, Mark; Rozek, Laura; Wolf, Gregory; Bowman, Rayleen; Fong, Kwun M.; Yang, Ian; Korst, Robert; Rathmell, W. Kimryn; Fantacone-Campbell, J. Leigh; Hooke, Jeffrey A.; Kovatich, Albert J.; Shriver, Craig D.; DiPersio, John; Drake, Bettina; Govindan, Ramaswamy; Heath, Sharon; Ley, Timothy; Van Tine, Brian; Westervelt, Peter; Rubin, Mark A.; Lee, Jung Il; Aredes, Natália D.; Mariamidze, Armaz; Lawrence, Michael S.; Godzik, Adam; Lopez-Bigas, Nuria; Stuart, Josh; Wheeler, David; Getz, Gad; Chen, Ken; Lazar, Alexander J.; Mills, Gordon B.; Karchin, Rachel; Ding, Li

    2018-01-01

    Identifying molecular cancer drivers is critical for precision oncology. Multiple advanced algorithms to identify drivers now exist, but systematic attempts to combine and optimize them on large datasets are few. We report a PanCancer and PanSoftware analysis spanning 9,423 tumor exomes (comprising

  1. 29 CFR 541.504 - Drivers who sell.

    Science.gov (United States)

    2010-07-01

    ... DELIMITING THE EXEMPTIONS FOR EXECUTIVE, ADMINISTRATIVE, PROFESSIONAL, COMPUTER AND OUTSIDE SALES EMPLOYEES Outside Sales Employees § 541.504 Drivers who sell. (a) Drivers who deliver products and also sell such products may qualify as exempt outside sales employees only if the employee has a primary duty of making...

  2. Functionally Assessing Candidate Drivers Advances Precision Cancer Medicine.

    Science.gov (United States)

    Scott, Kenneth L; Powers, Scott

    2016-08-08

    The complexity of genomic alterations in cancer has made it difficult to identify oncogenic drivers for the development of targeted therapies. The study by Berger et al. in this issue of Cancer Cell demonstrates that high-throughput functional profiling can uncover impactful mutations and oncogenic driver alleles. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Design and validation of advanced driver assistance systems

    NARCIS (Netherlands)

    Gietelink, O.J.

    2007-01-01

    This thesis presents new tools and methods for the design and validation of advanced driver assistance systems (ADASs). ADASs aim to improve driving comfort and traffic safety by assisting the driver in recognizing and reacting to potentially dangerous traffic situations. A major challenge in

  4. Discovery of cancer common and specific driver gene sets

    Science.gov (United States)

    2017-01-01

    Abstract Cancer is known as a disease mainly caused by gene alterations. Discovery of mutated driver pathways or gene sets is becoming an important step to understand molecular mechanisms of carcinogenesis. However, systematically investigating commonalities and specificities of driver gene sets among multiple cancer types is still a great challenge, but this investigation will undoubtedly benefit deciphering cancers and will be helpful for personalized therapy and precision medicine in cancer treatment. In this study, we propose two optimization models to de novo discover common driver gene sets among multiple cancer types (ComMDP) and specific driver gene sets of one certain or multiple cancer types to other cancers (SpeMDP), respectively. We first apply ComMDP and SpeMDP to simulated data to validate their efficiency. Then, we further apply these methods to 12 cancer types from The Cancer Genome Atlas (TCGA) and obtain several biologically meaningful driver pathways. As examples, we construct a common cancer pathway model for BRCA and OV, infer a complex driver pathway model for BRCA carcinogenesis based on common driver gene sets of BRCA with eight cancer types, and investigate specific driver pathways of the liquid cancer lymphoblastic acute myeloid leukemia (LAML) versus other solid cancer types. In these processes more candidate cancer genes are also found. PMID:28168295

  5. Improvements in Symbol Sign Design To Aid Older Drivers

    Science.gov (United States)

    1995-08-01

    Studies have shown that older drivers have higher rates of accidents, injuries, and fatalities on a per-mile-driven basis. A major cause of roadway accidents for older drivers is failure to heed traffic signs. Previous research found that older drive...

  6. 78 FR 64267 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

    Science.gov (United States)

    2013-10-28

    ...-0184] Qualification of Drivers; Exemption Applications; Diabetes Mellitus AGENCY: Federal Motor Carrier... against persons with insulin- treated diabetes mellitus (ITDM) operating commercial motor vehicles (CMVs... such an exemption from the diabetes prohibition in 49 CFR 391.41(b)(3), which applies to drivers of...

  7. 78 FR 78479 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

    Science.gov (United States)

    2013-12-26

    ...-0192] Qualification of Drivers; Exemption Applications; Diabetes Mellitus AGENCY: Federal Motor Carrier... insulin- treated diabetes mellitus (ITDM) operating commercial motor vehicles (CMVs) in interstate... diabetes prohibition in 49 CFR 391.41(b)(3), which applies to drivers of CMVs in interstate commerce...

  8. Guiding Teen Drivers (A Cup of Health with CDC)

    Centers for Disease Control (CDC) Podcasts

    Motor-vehicle crashes are the leading cause of death among teens. Parents have a big influence on young drivers and can help them reduce their risk for being involved in a crash. In this podcast, Amy Jewett discusses what parents can do to help keep young drivers safer on the road.

  9. Priming Drivers before Handover in Semi-Autonomous Cars

    NARCIS (Netherlands)

    van der Heiden, R.M.A.; Iqbal, Shamsi T.; Janssen, C.P.

    2017-01-01

    Semi-autonomous vehicles occasionally require control to be handed over to the driver in situations where the vehicle is unable to operate safely. Currently, such handover requests require the driver to take control almost instantaneously. We investigate how auditory pre-alerts that occur well

  10. Improved power quality based high brightness LED lamp driver

    African Journals Online (AJOL)

    user

    consists of a PFC Cuk DC-DC converter which operates in continuous conduction mode (CCM) to improve the ... In proposed LED driver as shown in Figure 1, a Cuk buck boost AC-DC converter ... Design and Analysis of Proposed LED Driver.

  11. Observed and projected drivers of emerging infectious diseases in Europe.

    Science.gov (United States)

    Semenza, Jan C; Rocklöv, Joacim; Penttinen, Pasi; Lindgren, Elisabet

    2016-10-01

    Emerging infectious diseases are of international concern because of the potential for, and impact of, pandemics; however, they are difficult to predict. To identify the drivers of disease emergence, we analyzed infectious disease threat events (IDTEs) detected through epidemic intelligence collected at the European Centre for Disease Prevention and Control (ECDC) between 2008 and 2013, and compared the observed results with a 2008 ECDC foresight study of projected drivers of future IDTEs in Europe. Among 10 categories of IDTEs, foodborne and waterborne IDTEs were the most common, vaccine-preventable IDTEs caused the highest number of cases, and airborne IDTEs caused the most deaths. Observed drivers for each IDTE were sorted into three main groups: globalization and environmental drivers contributed to 61% of all IDTEs, public health system drivers contributed to 21%, and social and demographic drivers to 18%. A multiple logistic regression analysis showed that four of the top five drivers for observed IDTEs were in the globalization and environment group. In the observational study, the globalization and environment group was related to all IDTE categories, but only to five of eight categories in the foresight study. Directly targeting these drivers with public health interventions may diminish the chances of IDTE occurrence from the outset. © 2016 New York Academy of Sciences.

  12. The definition of and drivers of new product performance

    DEFF Research Database (Denmark)

    Jespersen, Kristina Risom; Juhl, Hans Jørn

    In the last three decades academic research on new product development has tried to identify the drivers of new product development performance. This body of research is characterised by a vast amount of different definitions of both the drivers of new product performance and the performance...

  13. Lane-changing model with dynamic consideration of driver's propensity

    Science.gov (United States)

    Wang, Xiaoyuan; Wang, Jianqiang; Zhang, Jinglei; Ban, Xuegang Jeff

    2015-07-01

    Lane-changing is the driver's selection result of the satisfaction degree in different lane driving conditions. There are many different factors influencing lane-changing behavior, such as diversity, randomicity and difficulty of measurement. So it is hard to accurately reflect the uncertainty of drivers' lane-changing behavior. As a result, the research of lane-changing models is behind that of car-following models. Driver's propensity is her/his emotion state or the corresponding preference of a decision or action toward the real objective traffic situations under the influence of various dynamic factors. It represents the psychological characteristics of the driver in the process of vehicle operation and movement. It is an important factor to influence lane-changing. In this paper, dynamic recognition of driver's propensity is considered during simulation based on its time-varying discipline and the analysis of the driver's psycho-physic characteristics. The Analytic Hierarchy Process (AHP) method is used to quantify the hierarchy of driver's dynamic lane-changing decision-making process, especially the influence of the propensity. The model is validated using real data. Test results show that the developed lane-changing model with the dynamic consideration of a driver's time-varying propensity and the AHP method are feasible and with improved accuracy.

  14. Truck Drivers' Use of the Internet: A Mobile Health Lifeline.

    Science.gov (United States)

    Heaton, Karen; Combs, Bryan; Griffin, Russell

    2017-06-01

    Because of their social isolation, irregular and unpredictable schedules, limited access to health care, and long periods of travel, long-haul truckers may benefit from the use of mobile health applications on Internet-capable devices. The purpose of this study was to determine Internet access and usage among a sample of long-haul truck drivers. In this cross-sectional study, truck drivers completed a pencil and paper survey with questions on demographics, work and health histories, and Internet access and usage for both personal and job reasons. A total of 106 truck drivers were recruited from trucking industry trade shows, by word of mouth, and directly from trucking companies. Overall, the truck drivers' use of the Internet was limited. Their usage for personal and job-related reasons differed. Social connectivity and access to health and wellness information were important during personal usage time. Job-related Internet use was highly practical, and applied to seeking information for directions and maps, fuel stops and pricing, and communicating with employers or transmitting documents. Age and experience were associated with Internet use. Younger, less-experienced drivers used the Internet more than older, experienced drivers. Targeted mobile health messaging may be a useful tool to inform truck drivers of health conditions and plans, and may provide links to primary care providers needing to monitor or notify drivers of diagnostic results or treatment plans.

  15. Knowledge, Attitude and Practice of Commercial Drivers in Dar es ...

    African Journals Online (AJOL)

    Purpose: The objective of this study was, first, to assess the knowledge, attitude and practice of commercial drivers in Dar es Salaam with regard to medicines that impair driving, and second, to evaluate the adequacy of antihistamine label information. Methods: Drivers were interviewed using a questionnaire after obtaining ...

  16. Alpena Community College Commercial Driver's License Program. Evaluation Summary.

    Science.gov (United States)

    Alpena Community Coll., MI.

    The Alpena Community College (ACC) Drivers Education Program was developed to deliver a basic skills program providing specific job-related basic skills instruction to approximately 300 workers throughout Michigan who desired to pass the Commercial Drivers License (CDL) examination. Other program goals were to establish greater partnerships…

  17. Intersection assistance : A safe solution for older drivers?

    NARCIS (Netherlands)

    Dotzauer, Mandy; Caljouw, Simone R.; de Waard, Dick; Brouwer, Wiebo H.

    2013-01-01

    Within the next few decades, the number of older drivers operating a vehicle will increase rapidly (Eurostat, 2011). As age increases so does physical vulnerability, age-related impairments, and the risk of being involved in a fatal crashes. Older drivers experience problems in driving situations

  18. 32 CFR 634.10 - Remedial driver training programs.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Remedial driver training programs. 634.10 Section 634.10 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) LAW ENFORCEMENT AND CRIMINAL INVESTIGATIONS MOTOR VEHICLE TRAFFIC SUPERVISION Driving Privileges § 634.10 Remedial driver training programs. (a) Navy...

  19. Factors associated with suicide ideation among subway drivers in Korea.

    Science.gov (United States)

    Byun, Junsu; Kim, Hyoung-Ryoul; Lee, Hye-Eun; Kim, Se-Eun; Lee, Jongin

    2016-01-01

    There were several suicide events of subway drivers in Korea. The aim of this study is to explore work-related factors associated with suicide ideation among subway drivers. We analyzed data from 980 male subway drivers. A section of the Korean version of the Composite International Diagnostic Interview (K-CIDI 2.1) was administered by trained interviewers to judge whether a driver has suicide ideation and to diagnose psychiatric disorders. A questionnaire was also administered to collect data on sociodemographic characteristics, work environments, occupational stress, person under train (PUT) experience, and work-related problems. Occupational stress was examined by using the Korean Occupational Stress Scale (KOSS). Logistic regression was applied to evaluate the association between work-related factors and suicide ideation among subway drivers. Regarding work-related problems, conflict with passengers and sudden stops due to the emergency bell were significantly associated with suicide ideation. MDD, PTSD, and panic disorder were strongly associated with suicide ideation. In the analysis of occupational stress, insufficient job control (OR 2.34) and lack of reward (OR 2.52) were associated with suicide ideation even after being adjusted for psychiatric disorders and other work-related factors. Insufficient job control and lack of reward were associated with suicide ideation among subway drivers. Strategies for drivers to have autonomy while working and to achieve effort-reward balance should be implemented. Furthermore, drivers who have experienced negative work-related problems should be managed appropriately.

  20. Older drivers and ADAS : which systems improve road safety?

    NARCIS (Netherlands)

    Davidse, R.J.

    2006-01-01

    In the coming decades, the number of older drivers that experiences difficulties in traffic as a result of functional limitations will strongly increase. Advanced Driver Assistance Systems (ADAS) could resolve some of these difficulties, by providing personal assistance in a road environment that

  1. Highly automated driving, secondary task performance, and driver state.

    Science.gov (United States)

    Merat, Natasha; Jamson, A Hamish; Lai, Frank C H; Carsten, Oliver

    2012-10-01

    A driving simulator study compared the effect of changes in workload on performance in manual and highly automated driving. Changes in driver state were also observed by examining variations in blink patterns. With the addition of a greater number of advanced driver assistance systems in vehicles, the driver's role is likely to alter in the future from an operator in manual driving to a supervisor of highly automated cars. Understanding the implications of such advancements on drivers and road safety is important. A total of 50 participants were recruited for this study and drove the simulator in both manual and highly automated mode. As well as comparing the effect of adjustments in driving-related workload on performance, the effect of a secondary Twenty Questions Task was also investigated. In the absence of the secondary task, drivers' response to critical incidents was similar in manual and highly automated driving conditions. The worst performance was observed when drivers were required to regain control of driving in the automated mode while distracted by the secondary task. Blink frequency patterns were more consistent for manual than automated driving but were generally suppressed during conditions of high workload. Highly automated driving did not have a deleterious effect on driver performance, when attention was not diverted to the distracting secondary task. As the number of systems implemented in cars increases, an understanding of the implications of such automation on drivers' situation awareness, workload, and ability to remain engaged with the driving task is important.

  2. 78 FR 50486 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

    Science.gov (United States)

    2013-08-19

    ...-0182] Qualification of Drivers; Exemption Applications; Diabetes Mellitus AGENCY: Federal Motor Carrier... individuals for exemption from the prohibition against persons with insulin-treated diabetes mellitus (ITDM... revision must provide for individual assessment of drivers with diabetes mellitus, and be consistent with...

  3. 76 FR 79756 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

    Science.gov (United States)

    2011-12-22

    ...-0326] Qualification of Drivers; Exemption Applications; Diabetes Mellitus AGENCY: Federal Motor Carrier... individuals for exemption from the prohibition against persons with insulin-treated diabetes mellitus (ITDM...).\\1\\ The revision must provide for individual assessment of drivers with diabetes mellitus, and be...

  4. 77 FR 48587 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

    Science.gov (United States)

    2012-08-14

    ...-0217] Qualification of Drivers; Exemption Applications; Diabetes Mellitus AGENCY: Federal Motor Carrier... individuals for exemption from the prohibition against persons with insulin-treated diabetes mellitus (ITDM... drivers with diabetes mellitus, and be consistent with the criteria described in section 4018 of the...

  5. 77 FR 59447 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

    Science.gov (United States)

    2012-09-27

    ...-0281] Qualification of Drivers; Exemption Applications; Diabetes Mellitus AGENCY: Federal Motor Carrier... individuals for exemption from the prohibition against persons with insulin-treated diabetes mellitus (ITDM... drivers with diabetes mellitus, and be consistent with the criteria described in section 4018 of the...

  6. 78 FR 50482 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

    Science.gov (United States)

    2013-08-19

    ...-0183] Qualification of Drivers; Exemption Applications; Diabetes Mellitus AGENCY: Federal Motor Carrier... individuals for exemption from the prohibition against persons with insulin-treated diabetes mellitus (ITDM... revision must provide for individual assessment of drivers with diabetes mellitus, and be consistent with...

  7. 77 FR 18302 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

    Science.gov (United States)

    2012-03-27

    ...-0043] Qualification of Drivers; Exemption Applications; Diabetes Mellitus AGENCY: Federal Motor Carrier... individuals for exemption from the prohibition against persons with insulin-treated diabetes mellitus (ITDM... for individual assessment of drivers with diabetes mellitus, and be consistent with the criteria...

  8. 77 FR 17111 - Qualification of Drivers; Exemption Applications; Diabetes Mellitus

    Science.gov (United States)

    2012-03-23

    ...-0042] Qualification of Drivers; Exemption Applications; Diabetes Mellitus AGENCY: Federal Motor Carrier... individuals for exemption from the prohibition against persons with insulin-treated diabetes mellitus (ITDM... revision must provide for individual assessment of drivers with diabetes mellitus, and be consistent with...

  9. China-US-Japan workshop on laser plasma and drivers

    International Nuclear Information System (INIS)

    1994-01-01

    Organized by China Institute of Applied Physics and Computational Mathematics (IMPCM) and other 5 organizations, China-US-Japan Workshop on Laser Plasma and Drivers, LPD'94, was held on October 17-21, 1994 at Fragrant Hill Hotel, Beijing, China. Main topics includes: target and plasma physics, ICF Experiments, ICF drivers, etc.. More than 50 pieces of papers are included in the proceedings

  10. 78 FR 29431 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2013-05-20

    ..., driving in congested urban areas exposes the driver to more pedestrian and vehicular traffic than exists... qualification file if he/she is self-employed. The driver must have a copy of the certification when driving... your comments, please include a self-addressed, stamped envelope or postcard or print the...

  11. 78 FR 37274 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2013-06-20

    ..., driving in congested urban areas exposes the driver to more pedestrian and vehicular traffic than exists... qualification file if he/she is self-employed. The driver must have a copy of the certification when driving... that we received your comments, please include a self-addressed, stamped envelope or postcard or print...

  12. 78 FR 34141 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2013-06-06

    .... Moreover, driving in congested urban areas exposes the driver to more pedestrian and vehicular traffic than... qualification file if he/she is self-employed. The driver must have a copy of the certification when driving... your comments, please include a self-addressed, stamped envelope or postcard or print the...

  13. 77 FR 31427 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2012-05-25

    .... Moreover, driving in congested urban areas exposes the driver to more pedestrian and vehicular traffic than... qualification file if he/she is self-employed. The driver must have a copy of the certification when driving... that we received your comments, please include a self-addressed, stamped envelope or postcard or print...

  14. 78 FR 41188 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2013-07-09

    ..., driving in congested urban areas exposes the driver to more pedestrian and vehicular traffic than exists... qualification file if he/she is self-employed. The driver must have a copy of the certification when driving... your comments, please include a self-addressed, stamped envelope or postcard or print the...

  15. 77 FR 71669 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2012-12-03

    .... Moreover, driving in congested urban areas exposes the driver to more pedestrian and vehicular traffic than... qualification file if he/she is self-employed. The driver must have a copy of the certification when driving... that we received your comments, please include a self-addressed, stamped envelope or postcard or print...

  16. 77 FR 44708 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2012-07-30

    .... Moreover, driving in congested urban areas exposes the driver to more pedestrian and vehicular traffic than... qualification file if he/she is self-employed. The driver must have a copy of the certification when driving... that we received your comments, please include a self-addressed, stamped envelope or postcard or print...

  17. 78 FR 56986 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2013-09-16

    .... Moreover, driving in congested urban areas exposes the driver to more pedestrian and vehicular traffic than... qualification file if he/she is self-employed. The driver must have a copy of the certification when driving... that we received your comments, please include a self-addressed, stamped envelope or postcard or print...

  18. 77 FR 10608 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2012-02-22

    .... Moreover, driving in congested urban areas exposes the driver to more pedestrian and vehicular traffic than... qualification file if he/she is self-employed. The driver must have a copy of the certification when driving... you want acknowledgement that we received your comments, please include a self-addressed, stamped...

  19. 77 FR 33558 - Qualification of Drivers; Exemption Applications; Vision

    Science.gov (United States)

    2012-06-06

    ..., driving in congested urban areas exposes the driver to more pedestrian and vehicular traffic than exists... qualification file if he/she is self-employed. The driver must have a copy of the certification when driving... that we received your comments, please include a self-addressed, stamped envelope or postcard or print...

  20. TRENDS AND ISSUES IN SAFE DRIVER ASSISTANCE SYSTEMS

    Directory of Open Access Journals (Sweden)

    Sadayuki TSUGAWA

    2006-01-01

    Full Text Available In recent years, ITS projects in Japan, Europe and the US have been characterized by a strong emphasis on safe driver assistance systems designed to prevent traffic accidents. As it has become clear that eradicating accidents will be impossible by means of vehicle passive safety and single-vehicle active safety efforts alone, research and development of systems for preventing accidents through road-vehicle cooperation and vehicle-vehicle cooperation have been promoted in Japan (ASV, AHS, Europe (PReVENT, SAFESPOT and the US (VII. The key to such technology is road-to-vehicle communications and inter-vehicle communications. On the other hand, a number of driver assistance systems have been brought to market, including lidar-based forward collision warnings, ACC, lane keeping support and drowsiness warnings, but their penetration rates in Japan are extremely low. Furthermore, one major challenge is that safe driver assistance systems based on road-vehicle and vehicle-vehicle cooperation are premised upon a high penetration rate. Finally, we introduce a system for improving driver acceptance of safe driver assistance systems based on driver monitoring and forward monitoring as well as cooperative driver assistance systems for elderly drivers, an issue now receiving attention in Japan.