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Sample records for drive neutralization escape

  1. Viral escape from HIV-1 neutralizing antibodies drives increased plasma neutralization breadth through sequential recognition of multiple epitopes and immunotypes.

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    Constantinos Kurt Wibmer

    2013-10-01

    Full Text Available Identifying the targets of broadly neutralizing antibodies to HIV-1 and understanding how these antibodies develop remain important goals in the quest to rationally develop an HIV-1 vaccine. We previously identified a participant in the CAPRISA Acute Infection Cohort (CAP257 whose plasma neutralized 84% of heterologous viruses. In this study we showed that breadth in CAP257 was largely due to the sequential, transient appearance of three distinct broadly neutralizing antibody specificities spanning the first 4.5 years of infection. The first specificity targeted an epitope in the V2 region of gp120 that was also recognized by strain-specific antibodies 7 weeks earlier. Specificity for the autologous virus was determined largely by a rare N167 antigenic variant of V2, with viral escape to the more common D167 immunotype coinciding with the development of the first wave of broadly neutralizing antibodies. Escape from these broadly neutralizing V2 antibodies through deletion of the glycan at N160 was associated with exposure of an epitope in the CD4 binding site that became the target for a second wave of broadly neutralizing antibodies. Neutralization by these CD4 binding site antibodies was almost entirely dependent on the glycan at position N276. Early viral escape mutations in the CD4 binding site drove an increase in wave two neutralization breadth, as this second wave of heterologous neutralization matured to recognize multiple immunotypes within this site. The third wave targeted a quaternary epitope that did not overlap any of the four known sites of vulnerability on the HIV-1 envelope and remains undefined. Altogether this study showed that the human immune system is capable of generating multiple broadly neutralizing antibodies in response to a constantly evolving viral population that exposes new targets as a consequence of escape from earlier neutralizing antibodies.

  2. Viral escape from neutralizing antibodies in early subtype A HIV-1 infection drives an increase in autologous neutralization breadth.

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    Megan K Murphy

    2013-02-01

    Full Text Available Antibodies that neutralize (nAbs genetically diverse HIV-1 strains have been recovered from a subset of HIV-1 infected subjects during chronic infection. Exact mechanisms that expand the otherwise narrow neutralization capacity observed during early infection are, however, currently undefined. Here we characterized the earliest nAb responses in a subtype A HIV-1 infected Rwandan seroconverter who later developed moderate cross-clade nAb breadth, using (i envelope (Env glycoproteins from the transmitted/founder virus and twenty longitudinal nAb escape variants, (ii longitudinal autologous plasma, and (iii autologous monoclonal antibodies (mAbs. Initially, nAbs targeted a single region of gp120, which flanked the V3 domain and involved the alpha2 helix. A single amino acid change at one of three positions in this region conferred early escape. One immunoglobulin heavy chain and two light chains recovered from autologous B cells comprised two mAbs, 19.3H-L1 and 19.3H-L3, which neutralized the founder Env along with one or three of the early escape variants carrying these mutations, respectively. Neither mAb neutralized later nAb escape or heterologous Envs. Crystal structures of the antigen-binding fragments (Fabs revealed flat epitope contact surfaces, where minimal light chain mutation in 19.3H-L3 allowed for additional antigenic interactions. Resistance to mAb neutralization arose in later Envs through alteration of two glycans spatially adjacent to the initial escape signatures. The cross-neutralizing nAbs that ultimately developed failed to target any of the defined V3-proximal changes generated during the first year of infection in this subject. Our data demonstrate that this subject's first recognized nAb epitope elicited strain-specific mAbs, which incrementally acquired autologous breadth, and directed later B cell responses to target distinct portions of Env. This immune re-focusing could have triggered the evolution of cross

  3. Autologous HIV-1 neutralizing antibodies: emergence of neutralization-resistant escape virus and subsequent development of escape virus neutralizing antibodies

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    Arendrup, M; Nielsen, C; Hansen, J E

    1992-01-01

    The capacity of consecutive human sera to neutralize sequentially obtained autologous virus isolates was studied. HIV-1 was isolated three times over a 48-164-week period from three individuals immediately after seroconversion and from two individuals in later stages of infection. Development...... escape virus may be part of the explanation of the apparent failure of the immune system to control HIV infection....... of neutralizing antibodies to the primary virus isolates was detected 13-45 weeks after seroconversion. Emergence of escape virus with reduced sensitivity to neutralization by autologous sera was demonstrated. The patients subsequently developed neutralizing antibodies against the escape virus but after a delay...

  4. Autologous HIV-1 neutralizing antibodies: emergence of neutralization-resistant escape virus and subsequent development of escape virus neutralizing antibodies

    DEFF Research Database (Denmark)

    Arendrup, M; Nielsen, C; Hansen, J E

    1992-01-01

    The capacity of consecutive human sera to neutralize sequentially obtained autologous virus isolates was studied. HIV-1 was isolated three times over a 48-164-week period from three individuals immediately after seroconversion and from two individuals in later stages of infection. Development of ...... escape virus may be part of the explanation of the apparent failure of the immune system to control HIV infection.......The capacity of consecutive human sera to neutralize sequentially obtained autologous virus isolates was studied. HIV-1 was isolated three times over a 48-164-week period from three individuals immediately after seroconversion and from two individuals in later stages of infection. Development...... of neutralizing antibodies to the primary virus isolates was detected 13-45 weeks after seroconversion. Emergence of escape virus with reduced sensitivity to neutralization by autologous sera was demonstrated. The patients subsequently developed neutralizing antibodies against the escape virus but after a delay...

  5. Escape from neutralization by the respiratory syncytial virus-specific neutralizing monoclonal antibody palivizumab is driven by changes in on-rate of binding to the fusion protein

    International Nuclear Information System (INIS)

    Bates, John T.; Keefer, Christopher J.; Slaughter, James C.; Kulp, Daniel W.; Schief, William R.; Crowe, James E.

    2014-01-01

    The role of binding kinetics in determining neutralizing potency for antiviral antibodies is poorly understood. While it is believed that increased steady-state affinity correlates positively with increased virus-neutralizing activity, the relationship between association or dissociation rate and neutralization potency is unclear. We investigated the effect of naturally-occurring antibody resistance mutations in the RSV F protein on the kinetics of binding to palivizumab. Escape from palivizumab-mediated neutralization of RSV occurred with reduced association rate (K on ) for binding to RSV F protein, while alteration of dissociation rate (K off ) did not significantly affect neutralizing activity. Interestingly, linkage of reduced K on with reduced potency mirrored the effect of increased K on found in a high-affinity enhanced potency palivizumab variant (motavizumab). These data suggest that association rate is the dominant factor driving neutralization potency for antibodies to RSV F protein antigenic site A and determines the potency of antibody somatic variants or efficiency of escape of viral glycoprotein variants. - Highlights: • The relationship of affinity to neutralization for virus antibodies is uncertain. • Palivizumab binds to RSV escape mutant fusion proteins, but with reduced affinity. • Association rate (K on ) correlated well with the potency of neutralization

  6. Escape from neutralization by the respiratory syncytial virus-specific neutralizing monoclonal antibody palivizumab is driven by changes in on-rate of binding to the fusion protein

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    Bates, John T. [The Vanderbilt Vaccine Center, Departments of Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN (United States); Keefer, Christopher J. [The Vanderbilt Vaccine Center, Departments of Pediatrics, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN (United States); Slaughter, James C. [The Vanderbilt Vaccine Center, Departments of Biostatistics and Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN (United States); Kulp, Daniel W. [IAVI Neutralizing Antibody Center and Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA (United States); Schief, William R. [IAVI Neutralizing Antibody Center and Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA (United States); Center for HIV/AIDS Vaccine Immunology and Immunogen Discovery, The Scripps Research Institute, La Jolla, CA (United States); Crowe, James E., E-mail: james.crowe@vanderbilt.edu [The Vanderbilt Vaccine Center, Departments of Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN (United States); The Vanderbilt Vaccine Center, Departments of Pediatrics, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN (United States)

    2014-04-15

    The role of binding kinetics in determining neutralizing potency for antiviral antibodies is poorly understood. While it is believed that increased steady-state affinity correlates positively with increased virus-neutralizing activity, the relationship between association or dissociation rate and neutralization potency is unclear. We investigated the effect of naturally-occurring antibody resistance mutations in the RSV F protein on the kinetics of binding to palivizumab. Escape from palivizumab-mediated neutralization of RSV occurred with reduced association rate (K{sub on}) for binding to RSV F protein, while alteration of dissociation rate (K{sub off}) did not significantly affect neutralizing activity. Interestingly, linkage of reduced K{sub on} with reduced potency mirrored the effect of increased K{sub on} found in a high-affinity enhanced potency palivizumab variant (motavizumab). These data suggest that association rate is the dominant factor driving neutralization potency for antibodies to RSV F protein antigenic site A and determines the potency of antibody somatic variants or efficiency of escape of viral glycoprotein variants. - Highlights: • The relationship of affinity to neutralization for virus antibodies is uncertain. • Palivizumab binds to RSV escape mutant fusion proteins, but with reduced affinity. • Association rate (K{sub on}) correlated well with the potency of neutralization.

  7. Mechanisms of equine infectious anemia virus escape from neutralizing antibody responses define epitope specificity.

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    Sponseller, Brett A; Clark, Sandra K; Friedrich, Rachel A

    2012-08-01

    Determining mechanisms of viral escape to particular epitopes recognized by virus-neutralizing antibody can facilitate characterization of host-neutralizing antibody responses as type- versus group-specific, and provides necessary information for vaccine development. Our study reveals that a single N-glycan located in the 5' region of the Wyoming wild-type equine infectious anemia virus (EIAV) principal neutralizing domain (PND) accounts for the differences in neutralization phenotype observed between PND variants, while variations in charged amino acids within the PND do not appear to play a key role in viral escape. Site-directed mutagenesis and peptide mapping of a conserved epitope to neutralizing antibody in the 3' region of the PND showed rapid selective pressure for acquisition of a 5' PND N-glycan responsible for defining the specificity of the neutralizing-antibody response.

  8. Emergent neutrality drives phytoplankton species coexistence

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    Segura, Angel M.; Calliari, Danilo; Kruk, Carla; Conde, Daniel; Bonilla, Sylvia; Fort, Hugo

    2011-01-01

    The mechanisms that drive species coexistence and community dynamics have long puzzled ecologists. Here, we explain species coexistence, size structure and diversity patterns in a phytoplankton community using a combination of four fundamental factors: organism traits, size-based constraints, hydrology and species competition. Using a ‘microscopic’ Lotka–Volterra competition (MLVC) model (i.e. with explicit recipes to compute its parameters), we provide a mechanistic explanation of species coexistence along a niche axis (i.e. organismic volume). We based our model on empirically measured quantities, minimal ecological assumptions and stochastic processes. In nature, we found aggregated patterns of species biovolume (i.e. clumps) along the volume axis and a peak in species richness. Both patterns were reproduced by the MLVC model. Observed clumps corresponded to niche zones (volumes) where species fitness was highest, or where fitness was equal among competing species. The latter implies the action of equalizing processes, which would suggest emergent neutrality as a plausible mechanism to explain community patterns. PMID:21177680

  9. Feature Integration Drives Probabilistic Behavior in the Drosophila Escape Response.

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    von Reyn, Catherine R; Nern, Aljoscha; Williamson, W Ryan; Breads, Patrick; Wu, Ming; Namiki, Shigehiro; Card, Gwyneth M

    2017-06-21

    Animals rely on dedicated sensory circuits to extract and encode environmental features. How individual neurons integrate and translate these features into behavioral responses remains a major question. Here, we identify a visual projection neuron type that conveys predator approach information to the Drosophila giant fiber (GF) escape circuit. Genetic removal of this input during looming stimuli reveals that it encodes angular expansion velocity, whereas other input cell type(s) encode angular size. Motor program selection and timing emerge from linear integration of these two features within the GF. Linear integration improves size detection invariance over prior models and appropriately biases motor selection to rapid, GF-mediated escapes during fast looms. Our findings suggest feature integration, and motor control may occur as simultaneous operations within the same neuron and establish the Drosophila escape circuit as a model system in which these computations may be further dissected at the circuit level. VIDEO ABSTRACT. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. A method for ion distribution function evaluation using escaping neutral atom kinetic energy samples

    International Nuclear Information System (INIS)

    Goncharov, P.R.; Ozaki, T.; Veshchev, E.A.; Sudo, S.

    2008-01-01

    A reliable method to evaluate the probability density function for escaping atom kinetic energies is required for the analysis of neutral particle diagnostic data used to study the fast ion distribution function in fusion plasmas. Digital processing of solid state detector signals is proposed in this paper as an improvement of the simple histogram approach. Probability density function for kinetic energies of neutral particles escaping from the plasma has been derived in a general form taking into account the plasma ion energy distribution, electron capture and loss rates, superposition along the diagnostic sight line and the magnetic surface geometry. A pseudorandom number generator has been realized that enables a sample of escaping neutral particle energies to be simulated for given plasma parameters and experimental conditions. Empirical probability density estimation code has been developed and tested to reconstruct the probability density function from simulated samples assuming. Maxwellian and classical slowing down plasma ion energy distribution shapes for different temperatures and different slowing down times. The application of the developed probability density estimation code to the analysis of experimental data obtained by the novel Angular-Resolved Multi-Sightline Neutral Particle Analyzer has been studied to obtain the suprathermal particle distributions. The optimum bandwidth parameter selection algorithm has also been realized. (author)

  11. Early low-titer neutralizing antibodies impede HIV-1 replication and select for virus escape.

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    Katharine J Bar

    Full Text Available Single genome sequencing of early HIV-1 genomes provides a sensitive, dynamic assessment of virus evolution and insight into the earliest anti-viral immune responses in vivo. By using this approach, together with deep sequencing, site-directed mutagenesis, antibody adsorptions and virus-entry assays, we found evidence in three subjects of neutralizing antibody (Nab responses as early as 2 weeks post-seroconversion, with Nab titers as low as 1∶20 to 1∶50 (IC(50 selecting for virus escape. In each of the subjects, Nabs targeted different regions of the HIV-1 envelope (Env in a strain-specific, conformationally sensitive manner. In subject CH40, virus escape was first mediated by mutations in the V1 region of the Env, followed by V3. HIV-1 specific monoclonal antibodies from this subject mapped to an immunodominant region at the base of V3 and exhibited neutralizing patterns indistinguishable from polyclonal antibody responses, indicating V1-V3 interactions within the Env trimer. In subject CH77, escape mutations mapped to the V2 region of Env, several of which selected for alterations of glycosylation. And in subject CH58, escape mutations mapped to the Env outer domain. In all three subjects, initial Nab recognition was followed by sequential rounds of virus escape and Nab elicitation, with Nab escape variants exhibiting variable costs to replication fitness. Although delayed in comparison with autologous CD8 T-cell responses, our findings show that Nabs appear earlier in HIV-1 infection than previously recognized, target diverse sites on HIV-1 Env, and impede virus replication at surprisingly low titers. The unexpected in vivo sensitivity of early transmitted/founder virus to Nabs raises the possibility that similarly low concentrations of vaccine-induced Nabs could impair virus acquisition in natural HIV-1 transmission, where the risk of infection is low and the number of viruses responsible for transmission and productive clinical

  12. Neutralizing antibody response during human immunodeficiency virus type 1 infection: type and group specificity and viral escape

    DEFF Research Database (Denmark)

    Arendrup, M; Sönnerborg, A; Svennerholm, B

    1993-01-01

    of recombinant soluble gp120IIIB to cell-associated CD4, but group-specific virus neutralization required binding of NA to HIV-1 prior to viral attachment to target cells. Consecutive escape virus isolates were tested for sensitivity to neutralization by heterologous sera. Only minor differences were...

  13. Structural Basis for Escape of Human Astrovirus from Antibody Neutralization: Broad Implications for Rational Vaccine Design

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    Bogdanoff, Walter A.; Perez, Edmundo I.; López, Tomás; Arias, Carlos F.; DuBois, Rebecca M. (UNAM-Mexico); (UCSC)

    2017-10-25

    a single amino acid mutation induces a structural change in a loop that is responsible for antibody binding. Our findings reveal how viruses can escape antibody neutralization and provide insight for the rational design of vaccines to elicit diverse antibodies that provide broader protection from infection.

  14. A transmission/escape probabilities model for neutral particle transport in the outer regions of a diverted tokamak

    International Nuclear Information System (INIS)

    Stacey, W.M.

    1992-12-01

    A new computational model for neutral particle transport in the outer regions of a diverted tokamak plasma chamber is presented. The model is based on the calculation of transmission and escape probabilities using first-flight integral transport theory and the balancing of fluxes across the surfaces bounding the various regions. The geometrical complexity of the problem is included in precomputed probabilities which depend only on the mean free path of the region

  15. The HIV-1 V3 domain on field isolates: participation in generation of escape virus in vivo and accessibility to neutralizing antibodies

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    Arendrup, M; Akerblom, L; Heegaard, P M

    1995-01-01

    patterns against V3 peptides corresponding to sequential primary and escape field isolates, with the strongest reactivity against late isolated escape virus. These observations suggest that the neutralization epitope was influenced by the appearance of mutations. When used as immunogen in rabbits, V3...

  16. Neutralization Interfering Antibodies: A “Novel” Example of Humoral Immune Dysfunction Facilitating Viral Escape?

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    Roberto Burioni

    2012-09-01

    Full Text Available The immune response against some viral pathogens, in particular those causing chronic infections, is often ineffective notwithstanding a robust humoral neutralizing response. Several evasion mechanisms capable of subverting the activity of neutralizing antibodies (nAbs have been described. Among them, the elicitation of non-neutralizing and interfering Abs has been hypothesized. Recently, this evasion mechanism has acquired an increasing interest given its possible impact on novel nAb-based antiviral therapeutic and prophylactic approaches. In this review, we illustrate the mechanisms of Ab-mediated interference and the viral pathogens described in literature as able to adopt this “novel” evasion strategy.

  17. Neutralization Interfering Antibodies: A “Novel” Example of Humoral Immune Dysfunction Facilitating Viral Escape?

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    Nicasio, Mancini; Sautto, Giuseppe; Clementi, Nicola; Diotti, Roberta A.; Criscuolo, Elena; Castelli, Matteo; Solforosi, Laura; Clementi, Massimo; Burioni, Roberto

    2012-01-01

    The immune response against some viral pathogens, in particular those causing chronic infections, is often ineffective notwithstanding a robust humoral neutralizing response. Several evasion mechanisms capable of subverting the activity of neutralizing antibodies (nAbs) have been described. Among them, the elicitation of non-neutralizing and interfering Abs has been hypothesized. Recently, this evasion mechanism has acquired an increasing interest given its possible impact on novel nAb-based antiviral therapeutic and prophylactic approaches. In this review, we illustrate the mechanisms of Ab-mediated interference and the viral pathogens described in literature as able to adopt this “novel” evasion strategy. PMID:23170181

  18. Neutralization interfering antibodies: a "novel" example of humoral immune dysfunction facilitating viral escape?

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    Nicasio, Mancini; Sautto, Giuseppe; Clementi, Nicola; Diotti, Roberta A; Criscuolo, Elena; Castelli, Matteo; Solforosi, Laura; Clementi, Massimo; Burioni, Roberto

    2012-09-01

    The immune response against some viral pathogens, in particular those causing chronic infections, is often ineffective notwithstanding a robust humoral neutralizing response. Several evasion mechanisms capable of subverting the activity of neutralizing antibodies (nAbs) have been described. Among them, the elicitation of non-neutralizing and interfering Abs has been hypothesized. Recently, this evasion mechanism has acquired an increasing interest given its possible impact on novel nAb-based antiviral therapeutic and prophylactic approaches. In this review, we illustrate the mechanisms of Ab-mediated interference and the viral pathogens described in literature as able to adopt this "novel" evasion strategy.

  19. THE LYMAN ALPHA REFERENCE SAMPLE. V. THE IMPACT OF NEUTRAL ISM KINEMATICS AND GEOMETRY ON Lyα ESCAPE

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    Rivera-Thorsen, Thøger E.; Hayes, Matthew; Östlin, Göran; Duval, Florent; Sandberg, Andreas; Guaita, Lucia; Adamo, Angela [Department of Astronomy, Oskar Klein Centre, Stockholm University, AlbaNova University Centre, SE-106 91 Stockholm (Sweden); Orlitová, Ivana [Astronomical Institute, Academy of Sciences of the Czech Republic, Boční II, CZ-14131 Prague (Czech Republic); Verhamme, Anne; Schaerer, Daniel [Geneva Observatory, University of Geneva, 51 Chemin des Maillettes, CH-1290 Versoix (Switzerland); Mas-Hesse, J. Miguel [Centro de Astrobiología (CSIC–INTA), Departamento de Astrofísica, P.O. Box 78, E-28691 Villanueva de la Cañada (Spain); Cannon, John M. [Department of Physics and Astronomy, Macalester College, 1600 Grand Avenue, Saint Paul, MN 55105 (United States); Otí-Floranes, Héctor [Instituto de Astronomía, Universidad Nacional Autónoma de México, Apdo. Postal 106, B. C. 22800 Ensenada (Mexico); Atek, Hakim [Laboratoire d’Astrophysique, École Polytechnique Fédérale de Lausanne (EPFL), Observatoire, CH-1290 Sauverny (Switzerland); Herenz, E. Christian [Leibniz-Institut für Astrophysik (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany); Kunth, Daniel, E-mail: trive@astro.su.se [Institut d’Astrophysique de Paris, UMR 7095 CNRS and UPMC, 98 bis Bd Arago, F-75014 Paris (France); and others

    2015-05-20

    We present high-resolution far-UV spectroscopy of the 14 galaxies of the Lyα Reference Sample; a sample of strongly star-forming galaxies at low redshifts (0.028 < z < 0.18). We compare the derived properties to global properties derived from multi-band imaging and 21 cm H i interferometry and single-dish observations, as well as archival optical SDSS spectra. Besides the Lyα line, the spectra contain a number of metal absorption features allowing us to probe the kinematics of the neutral ISM and evaluate the optical depth and and covering fraction of the neutral medium as a function of line of sight velocity. Furthermore, we show how this, in combination with the precise determination of systemic velocity and good Lyα spectra, can be used to distinguish a model in which separate clumps together fully cover the background source, from the “picket fence” model named by Heckman et al. We find that no one single effect dominates in governing Lyα radiative transfer and escape. Lyα escape in our sample coincides with a maximum velocity-binned covering fraction of ≲0.9 and bulk outflow velocities of ≳50 km s{sup −1}, although a number of galaxies show these characteristics and yet little or no Lyα escape. We find that Lyα peak velocities, where available, are not consistent with a strong backscattered component, but rather with a simpler model of an intrinsic emission line overlaid by a blueshifted absorption profile from the outflowing wind. Finally, we find a strong anticorrelation between Hα equivalent width and maximum velocity-binned covering factor, and propose a heuristic explanatory model.

  20. Fast-ion transport and neutral beam current drive in ASDEX upgrade

    DEFF Research Database (Denmark)

    Geiger, B.; Weiland, M.; Jacobsen, Asger Schou

    2015-01-01

    The neutral beam current drive efficiency has been investigated in the ASDEX Upgrade tokamak by replacing on-axis neutral beams with tangential off-axis beams. A clear modification of the radial fast-ion profiles is observed with a fast-ion D-alpha diagnostic that measures centrally peaked profiles...

  1. The HIV-1 V3 domain on field isolates: participation in generation of escape virus in vivo and accessibility to neutralizing antibodies

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    Arendrup, M; Akerblom, L; Heegaard, P M

    1995-01-01

    The V3 domain is highly variable and induces HIV neutralizing antibodies (NA). Here we addressed the issues of 1) the participation of mutations in V3 in generation of neutralization resistant escape virus in vivo and 2) the applicability of synthetic V3 peptides corresponding to field isolates...... to induce neutralizing immune sera. Seven peptides corresponding to the V3 region of primary and escape virus from 3 HIV-1 infected patients were synthesized and used for antibody (Abs) studies and immunizations. The anti-V3 Abs titre in patient serum was generally low against peptides corresponding...... to autologous virus isolated later than the serum sample in contrast to the titre against peptides corresponding to virus isolated earlier than the serum sample. Furthermore, neutralizing anti-V3 monoclonal antibodies (MAbs) raised against V3 peptides from laboratory strains of HIV-1 showed distinct binding...

  2. Chikungunya virus neutralization antigens and direct cell-to-cell transmission are revealed by human antibody-escape mutants.

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    Chia Yin Lee

    2011-12-01

    Full Text Available Chikungunya virus (CHIKV is an alphavirus responsible for numerous epidemics throughout Africa and Asia, causing infectious arthritis and reportedly linked with fatal infections in newborns and elderly. Previous studies in animal models indicate that humoral immunity can protect against CHIKV infection, but despite the potential efficacy of B-cell-driven intervention strategies, there are no virus-specific vaccines or therapies currently available. In addition, CHIKV has been reported to elicit long-lasting virus-specific IgM in humans, and to establish long-term persistence in non-human primates, suggesting that the virus might evade immune defenses to establish chronic infections in man. However, the mechanisms of immune evasion potentially employed by CHIKV remain uncharacterized. We previously described two human monoclonal antibodies that potently neutralize CHIKV infection. In the current report, we have characterized CHIKV mutants that escape antibody-dependent neutralization to identify the CHIKV E2 domain B and fusion loop "groove" as the primary determinants of CHIKV interaction with these antibodies. Furthermore, for the first time, we have also demonstrated direct CHIKV cell-to-cell transmission, as a mechanism that involves the E2 domain A and that is associated with viral resistance to antibody-dependent neutralization. Identification of CHIKV sub-domains that are associated with human protective immunity, will pave the way for the development of CHIKV-specific sub-domain vaccination strategies. Moreover, the clear demonstration of CHIKV cell-to-cell transmission and its possible role in the establishment of CHIKV persistence, will also inform the development of future anti-viral interventions. These data shed new light on CHIKV-host interactions that will help to combat human CHIKV infection and inform future studies of CHIKV pathogenesis.

  3. The HIV-1 V3 domain on field isolates: participation in generation of escape virus in vivo and accessibility to neutralizing antibodies

    DEFF Research Database (Denmark)

    Arendrup, M; Akerblom, L; Heegaard, P M

    1995-01-01

    to induce neutralizing immune sera. Seven peptides corresponding to the V3 region of primary and escape virus from 3 HIV-1 infected patients were synthesized and used for antibody (Abs) studies and immunizations. The anti-V3 Abs titre in patient serum was generally low against peptides corresponding...... to autologous virus isolated later than the serum sample in contrast to the titre against peptides corresponding to virus isolated earlier than the serum sample. Furthermore, neutralizing anti-V3 monoclonal antibodies (MAbs) raised against V3 peptides from laboratory strains of HIV-1 showed distinct binding...... peptides corresponding to field isolates were highly immunogenic but failed to induce neutralizing or gp120-precipitating Abs. On the contrary, V3 peptide corresponding to the laboratory strain HXB2 induced HIV neutralizing, gp120-precipitating immune serum. In conclusion, these data suggest...

  4. A single amino acid substitution in the S1 and S2 Spike protein domains determines the neutralization escape phenotype of SARS-CoV.

    Science.gov (United States)

    Mitsuki, Yu-ya; Ohnishi, Kazuo; Takagi, Hirotaka; Oshima, Masamichi; Yamamoto, Takuya; Mizukoshi, Fuminori; Terahara, Kazutaka; Kobayashi, Kazuo; Yamamoto, Naoki; Yamaoka, Shoji; Tsunetsugu-Yokota, Yasuko

    2008-07-01

    In response to SARS-CoV infection, neutralizing antibodies are generated against the Spike (S) protein. Determination of the active regions that allow viral escape from neutralization would enable the use of these antibodies for future passive immunotherapy. We immunized mice with UV-inactivated SARS-CoV to generate three anti-S monoclonal antibodies, and established several neutralization escape mutants with S protein. We identified several amino acid substitutions, including Y442F and V601G in the S1 domain and D757N and A834V in the S2 region. In the presence of each neutralizing antibody, double mutants with substitutions in both domains exhibited a greater growth advantage than those with only one substitution. Importantly, combining two monoclonal antibodies that target different epitopes effected almost complete suppression of wild type virus replication. Thus, for effective passive immunotherapy, it is important to use neutralizing antibodies that recognize both the S1 and S2 regions.

  5. Exploring drive for thinness as a perfectionistic strategy to escape from shame experiences.

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    Ferreira, Cláudia; Trindade, Inês A; Ornelas, Luísa

    2015-05-20

    Perfectionistic self-presentation defines the attempt at presenting the self as perfect through the public concealment of personal defects and/or through the display of attributes perceived as capable to gather positive attention of others. Although perfectionism has long been considered a central aspect of eating psychopathology mediational studies between this construct and these conditions are scarce. This study aimed at examining the mediational role of body image-related perfectionistic self-presentation in the effects of external shame and internal shame on drive for thinness, in a sample of young women. Results revealed body image-related perfectionistic self-presentation as a significant mediator (p strategy to deal with shame when mediated by an endorsement in the belief that presenting a perfect body image is crucial to be accepted and valued by others. Study findings suggest that this perfectionistic strategy should be targeted while treating eating psychopathology.

  6. Applying antibody-sensitive hypervariable region 1-deleted hepatitis C virus to the study of escape pathways of neutralizing human monoclonal antibody AR5A

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    Velazquez-Moctezuma, Rodrigo; Law, Mansun; Bukh, Jens

    2017-01-01

    isolates with high antibody resistance, or antibodies with moderate potency, it remains challenging to induce escape mutations in vitro. Here, as proof-of-concept, we used antibody-sensitive HVR1-deleted (ΔHVR1) viruses to generate escape mutants for a human monoclonal antibody, AR5A, targeting a rare...... effect but sensitized the virus to AR5A. Of note, H77/JFH1L665S was non-viable. The resistance mutations did not affect cell-to-cell spread or E1/E2 interactions. Finally, introducing L665W, identified in genotype 1, into genotypes 2–6 parental and HVR1-deleted variants (not available for genotype 4a) we...... observed diverse effects on viral fitness and a universally pronounced reduction in AR5A sensitivity. Thus, we were able to take advantage of the neutralization-sensitive HVR1-deleted viruses to rapidly generate escape viruses aiding our understanding of the divergent escape pathways used by HCV to evade...

  7. Human monoclonal antibodies to a novel cluster of conformational epitopes on HCV E2 with resistance to neutralization escape in a genotype 2a isolate

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    Keck, Zhen-yong; Xia, Jinming; Wang, Yong

    2012-01-01

    regions that will be relevant for vaccine design, we employed yeast surface display of antibodies that bound to genotype 1a H77C E2 mutant proteins containing a substitution either at Y632A (to avoid selecting non-neutralizing antibodies) or D535A. A panel of nine human monoclonal antibodies (HMAbs......, when HCVcc were passaged in the presence of each of these antibodies, virus escape was not observed. Thus, the cluster of HC-84 epitopes, designated as antigenic domain D, is relevant for vaccine design for this highly diverse virus....

  8. Neutralizing antibody response during human immunodeficiency virus type 1 infection: type and group specificity and viral escape

    DEFF Research Database (Denmark)

    Arendrup, M; Sönnerborg, A; Svennerholm, B

    1993-01-01

    demonstrated, suggesting that the majority of the change in neutralization sensitivity is driven by the selective pressure of type-specific NA. Furthermore, no differences were observed in sensitivity to neutralization by anti-carbohydrate neutralizing monoclonal antibodies or the lectin concanavalin A......The paradox that group-specific neutralizing antibodies (NA) exist in the majority of human immunodeficiency virus type 1 (HIV-1)-infected patients, whereas the NA response against autologous HIV-1 virus isolates is highly type-specific, motivated us to study the type- and group-specific NA...

  9. Direct Torque Control for Three-Level Neutral Point Clamped Inverter-Fed Induction Motor Drive

    Directory of Open Access Journals (Sweden)

    M. K. Sahu

    2012-04-01

    Full Text Available Direct torque control (DTC is a control technique in AC drive systems to obtain high performance torque control. The classical DTC drive contains a pair of hysteresis comparators and suffers from variable switching frequency and high torque ripple. These problems can be solved by using space vector depending on the reference torque and flux. In this paper the space vector modulation technique is applied to the three-level Neutral Point Clamped (NPC inverter control in the proposed DTC-based induction motor drive system, resulting to a significant reduce of torque ripple. Three-level neutral point clamped inverters have been widely used in medium voltage applications. This type of inverters have several advantages over standard two-level VSI, such as greater number of levels in the output voltage waveforms, less harmonic distortion in voltage and current waveforms and lower switching frequencies. This paper emphasizes the derivation of switching states using the Space Vector Pulse Width Modulation (SVPWM technique. The control scheme is implemented using Matlab/Simulink. Experimental results using dSPACE validate the steady-state and the dynamic performance of the proposed control strategy.

  10. RAMI Analysis of Neutral Beam Heating and Current Drive System for ITER

    International Nuclear Information System (INIS)

    Chang, Doo Hee; Lee, Sang Il

    2009-01-01

    A RAMI (Reliability, Availability, Maintainability, Inspectability) analysis has been performed for the neutral beam (NB) heating and current drive (H and CD) system of ITER (International Thermonuclear Experimental Reactor) device. The objective of this analysis is to implement RAMI engineering requirements for the design and testing to prepare a reliability-centred plan for commissioning, operation, and maintenance of the system in the framework of a technical risk control to support the overall ITER Project. These RAMI requirements will correspond to the RAMI targets for the ITER project and the compensating provisions to reach them as deduced from the necessary actions to decrease the risk level of the function failure modes. The RAMI analyses have to match with the procurement plan of the system

  11. Fast wave current drive in neutral beam heated plasmas on DIII-D

    International Nuclear Information System (INIS)

    Petty, C.C.; Forest, C.B.; Pinsker, R.I.

    1997-04-01

    The physics of non-inductive current drive and current profile control using the fast magnetosonic wave has been demonstrated on the DIII-D tokamak. In non-sawtoothing discharges formed by neutral beam injection (NBI), the radial profile of the fast wave current drive (FWCD) was determined by the response of the loop voltage profile to co, counter, and symmetric antenna phasings, and was found to be in good agreement with theoretical models. The application of counter FWCD increased the magnetic shear reversal of the plasma and delayed the onset of sawteeth, compared to co FWCD. The partial absorption of fast waves by energetic beam ions at high harmonics of the ion cyclotron frequency was also evident from a build up of fast particle pressure near the magnetic axis and a correlated increase in the neutron rate. The anomalous fast particle pressure and neutron rate increased with increasing NBI power and peaked when a harmonic of the deuterium cyclotron frequency passed through the center of the plasma. The experimental FWCD efficiency was highest at 2 T where the interaction between the fast waves and the beam ions was weakest; as the magnetic field strength was lowered, the FWCD efficiency decreased to approximately half of the maximum theoretical value

  12. Current drive with fast waves, electron cyclotron waves, and neutral injection in the DIII-D tokamak

    International Nuclear Information System (INIS)

    Prater, R.; Petty, C.C.; Pinsker, R.I.

    1993-01-01

    Current drive experiments have been performed on the DIII-D tokamak using fast waves, electron cyclotron waves, and neutral injection. Fast wave experiments were performed using a 4-strap antenna with 1 MW of power at 60 MHz. These experiments showed effective heating of electrons, with a global heating efficiency equivalent to that of neutral injection even when the single pass damping was calculated to be as small as 5%. The damping was probably due to the effect of multiple passes of the wave through the plasma. Fast wave current drive experiments were performed with a toroidally directional phasing of the antenna straps. Currents driven by fast wave current drive (FWCD) in the direction of the main plasma current of up to 100 kA were found, not including a calculated 40 kA of bootstrap current. Experiments with FWCD in the counter current direction showed little current drive. In both cases, changes in the sawtooth behavior and the internal inductance qualitatively support the measurement of FWCD. Experiments on electron cyclotron current drive have shown that 100 kA of current can be driven by 1 MW of power at 60 GHz. Calculations with a Fokker-Planck code show that electron cyclotron current drive (ECCD) can be well predicted when the effects of electron trapping and of the residual electric field are included. Experiments on driving current with neutral injection showed that effective current drive could be obtained and discharges with full current drive were demonstrated. Interestingly, all of these methods of current drive had about the same efficiency. (Author)

  13. Feasibility of driving perpendicular rotation in core plasma by off-axis neutral beam injection to suppress microturbulence

    International Nuclear Information System (INIS)

    Hassam, A.B.

    1993-01-01

    Various aspects pertaining to driving perpendicular rotation in core plasma with neutral beam injection to suppress microturbulence are discussed. The assessment is based on the premise that a critical perpendicular velocity shear of order C s /L s is required to effect significant turbulence suppression. The equilibrium of a tokamak plasma rotating poloidally at such high frequencies is examined from drift-kinetic theory. It is shown that a substantial fraction of trapped particles is now detrapped. The calculation also shows that viscous damping from magnetic pumping falls off as the square of the poloidal speed. This reduction in viscous damping makes more efficacious the driving of large poloidal flows from off-axis neutral beam injection. The feasibility of exceeding the critical velocity shear is assessed, both for present day tokamaks as well as for reactor parameters. The magnetohydrodynamic stability of tokamak plasma rotating at high speeds with respect to Kelvin-Helmholtz and interchange modes is assessed

  14. Non-random escape pathways from a broadly neutralizing human monoclonal antibody map to a highly conserved region on the hepatitis C virus E2 glycoprotein encompassing amino acids 412-423.

    Directory of Open Access Journals (Sweden)

    Zhen-yong Keck

    2014-08-01

    Full Text Available A challenge for hepatitis C virus (HCV vaccine development is to define epitopes that are able to elicit protective antibodies against this highly diverse virus. The E2 glycoprotein region located at residues 412-423 is conserved and antibodies to 412-423 have broadly neutralizing activities. However, an adaptive mutation, N417S, is associated with a glycan shift in a variant that cannot be neutralized by a murine but by human monoclonal antibodies (HMAbs against 412-423. To determine whether HCV escapes from these antibodies, we analyzed variants that emerged when cell culture infectious HCV virions (HCVcc were passaged under increasing concentrations of a specific HMAb, HC33.1. Multiple nonrandom escape pathways were identified. Two pathways occurred in the context of an N-glycan shift mutation at N417T. At low antibody concentrations, substitutions of two residues outside of the epitope, N434D and K610R, led to variants having improved in vitro viral fitness and reduced sensitivity to HC33.1 binding and neutralization. At moderate concentrations, a S419N mutation occurred within 412-423 in escape variants that have greatly reduced sensitivity to HC33.1 but compromised viral fitness. Importantly, the variants generated from these pathways differed in their stability. N434D and K610R-associated variants were stable and became dominant as the virions were passaged. The S419N mutation reverted back to N419S when immune pressure was reduced by removing HC33.1. At high antibody concentrations, a mutation at L413I was observed in variants that were resistant to HC33.1 neutralization. Collectively, the combination of multiple escape pathways enabled the virus to persist under a wide range of antibody concentrations. Moreover, these findings pose a different challenge to vaccine development beyond the identification of highly conserved epitopes. It will be necessary for a vaccine to induce high potency antibodies that prevent the formation of escape

  15. Neutral-point current modeling and control for Neutral-Point Clamped three-level converter drive with small DC-link capacitors

    DEFF Research Database (Denmark)

    Maheshwari, Ram Krishan; Munk-Nielsen, Stig; Busquets-Monge, Sergio

    2011-01-01

    A Neutral-Point-Clamped (NPC) three-level inverter with small DC-link capacitors is presented in this paper. This inverter requires zero average neutral-point current for stable neutral-point potential. A simple carrier based modulation strategy is proposed for achieving zero average neutral......-point current. A new simplified model of the neutral-point voltage dynamics is derived for the proposed modulation strategy. This model shows that the neutral-point current is proportional to the power drawn from the converter and it enables the use of well established classical control theory for neutral......-point voltage controller design. A PI controller is used for neutral-point voltage balance. The implementation of the proposed modulation strategy and controller is simple. It does not require any information about the output phase currents. The controller is implemented in a 7.5 kW induction machine based...

  16. Noninfectious retrovirus particles drive the APOBEC3/Rfv3 dependent neutralizing antibody response.

    Directory of Open Access Journals (Sweden)

    Diana S Smith

    2011-10-01

    Full Text Available Members of the APOBEC3 family of deoxycytidine deaminases counteract a broad range of retroviruses in vitro through an indirect mechanism that requires virion incorporation and inhibition of reverse transcription and/or hypermutation of minus strand transcripts in the next target cell. The selective advantage to the host of this indirect restriction mechanism remains unclear, but valuable insights may be gained by studying APOBEC3 function in vivo. Apobec3 was previously shown to encode Rfv3, a classical resistance gene that controls the recovery of mice from pathogenic Friend retrovirus (FV infection by promoting a more potent neutralizing antibody (NAb response. The underlying mechanism does not involve a direct effect of Apobec3 on B cell function. Here we show that while Apobec3 decreased titers of infectious virus during acute FV infection, plasma viral RNA loads were maintained, indicating substantial release of noninfectious particles in vivo. The lack of plasma virion infectivity was associated with a significant post-entry block during early reverse transcription rather than G-to-A hypermutation. The Apobec3-dependent NAb response correlated with IgG binding titers against native, but not detergent-lysed virions. These findings indicate that innate Apobec3 restriction promotes NAb responses by maintaining high concentrations of virions with native B cell epitopes, but in the context of low virion infectivity. Finally, Apobec3 restriction was found to be saturable in vivo, since increasing FV inoculum doses resulted in decreased Apobec3 inhibition. By analogy, maximizing the release of noninfectious particles by modulating APOBEC3 expression may improve humoral immunity against pathogenic human retroviral infections.

  17. Chinks in the armor of the HIV-1 Envelope glycan shield: Implications for immune escape from anti-glycan broadly neutralizing antibodies.

    Science.gov (United States)

    Moyo, Thandeka; Ferreira, Roux-Cil; Davids, Reyaaz; Sonday, Zarinah; Moore, Penny L; Travers, Simon A; Wood, Natasha T; Dorfman, Jeffrey R

    2017-01-15

    Glycans on HIV-1 Envelope serve multiple functions including blocking epitopes from antibodies. We show that removal of glycan 301, a major target of anti-V3/glycan antibodies, has substantially different effects in two viruses. While glycan 301 on Du156.12 blocks epitopes commonly recognized by sera from chronically HIV-1-infected individuals, it does not do so on CAP45.G3, suggesting that removing the 301 glycan has a smaller effect on the integrity of the glycan shield in CAP45.G3. Changes in sensitivity to broadly neutralizing monoclonal antibodies suggest that the interaction between glycan 301 and the CD4 binding site differ substantially between these 2 viruses. Molecular modeling suggests that removal of glycan 301 likely exposes a greater surface area of the V3 and C4 regions in Du156.12. Our data indicate that the contribution of the 301 glycan to resistance to common neutralizing antibodies varies between viruses, allowing for easier selection for its loss in some viruses. Copyright © 2016 Elsevier B.V. All rights reserved.

  18. The driving force for magnetospheric convection

    Science.gov (United States)

    Johnson, F. S.

    1978-01-01

    Viscously driven magnetospheric models, as well as a model involving interconnection between the geomagnetic field and the magnetic field in the solar wind, have been proposed to describe the driving force for magnetospheric convection. Lack of a satisfactory theory for the interconnection in the latter model and, in the case of the viscous interaction models, inadequacies in predicting the quantity of the driving force, make these two classes of models less than successful. Accordingly, a mechanically driven magnetospheric model is proposed: solar wind plasma enters the magnetosphere around the neutral points, covers the inner surface of the magnetopause and subsequently expands, driving convection as it escapes from the open tail.

  19. On the NBI system for substantial current drive in a fusion power plant: Status and R and D needs for ion source and laser neutralizer

    Energy Technology Data Exchange (ETDEWEB)

    Franzen, P., E-mail: peter.franzen@ipp.mpg.de; Fantz, U.

    2014-11-15

    Highlights: • NBI is a candidate for a cw tokamak DEMO due to its high current drive efficiency. • The plug-in efficiency must be improved from the present 20–30% to more than 50%. • A suitable candidate is a photo neutralizer with almost 100% neutralization efficiency; basic feasibility studies are underway. • Cw operation with a large availability puts rather high demands on source operation with some safety margins, especially for the components with high power density loads (source back plate and extraction system). • Alternatives to the present use of cesium are under exploitations. - Abstract: The requirements for the heating and current drive systems of a fusion power plant will strongly depend on the DEMO scenario. The paper discusses the R and D needs for a neutral beam injection system — being a candidate due to the highest current drive efficiency — for the most demanding scenario, a steady state tokamak DEMO. Most important issues are the improvement of the wall-plug efficiency from the present ∼25% to the required 50–60% by improving the neutralization efficiency with a laser neutralizer system and the improvement of the reliability of the ion source operation. The demands on and the potential of decreasing the ion source operation pressure, as well as decreasing the amount of co-extracted electrons and backstreaming ions are discussed using the ITER requirements and solutions as basis. A further concern is the necessity of cesium for which either the cesium management must be improved or alternatives to cesium for the production of negative ions have to be identified.

  20. Design and Comparison of Cascaded H-Bridge, Modular Multilevel Converter, and 5-L Active Neutral Point Clamped Topologies for Motor Drive Applications

    Energy Technology Data Exchange (ETDEWEB)

    Marzoughi, Alinaghi [Virginia Tech, Blacksburg, VA (United States). Center for Power Electronics Systems; Burgos, Rolando [Virginia Tech, Blacksburg, VA (United States). Bradley Dept. of Electrical and Computer Engineering; Boroyevich, Dushan [Virginia Tech, Blacksburg, VA (United States). Bradley Dept. of Electrical and Computer Engineering; Xue, Yaosuo [Siemens Corporate Research, Princeton, NJ (United States). Power Electronics Dept.

    2018-03-01

    This paper presents the design procedure and comparison of converters currently used in medium-voltage high-power motor drive applications. For this purpose, the cascaded H-bridge (CHB), modular multilevel converter (MMC), and five-level active neutral point clamped (5-L ANPC) topologies are targeted. The design is performed using 1.7-kV insulated gate bipolar transistors (IGBTs) for CHB and MMC converters, and utilizing 3.3- and 4.5-kV IGBTs for 5-L ANPC topology as normally done in industry. The comparison is done between the designed converter topologies at three different voltage levels (4.16, 6.9, and 13.8 kV, with only the first two voltage levels in case of the 5-L ANPC) and two different power levels (3 and 5 MVA), in order to elucidate the dependence of different parameters on voltage and power rating. Finally, the comparison is done from several points of view such as efficiency, capacitive energy storage, semiconductor utilization, parts count (for measure of reliability), and power density.

  1. Natural selection and neutral evolution jointly drive population divergence between alpine and lowland ecotypes of the allopolyploid plant Anemone multifida (Ranunculaceae).

    Science.gov (United States)

    McEwen, Jamie R; Vamosi, Jana C; Rogers, Sean M

    2013-01-01

    Population differentiation can be driven in large part by natural selection, but selectively neutral evolution can play a prominent role in shaping patters of population divergence. The decomposition of the evolutionary history of populations into the relative effects of natural selection and selectively neutral evolution enables an understanding of the causes of population divergence and adaptation. In this study, we examined heterogeneous genomic divergence between alpine and lowland ecotypes of the allopolyploid plant, Anemone multifida. Using peak height and dominant AFLP data, we quantified population differentiation at non-outlier (neutral) and outlier loci to determine the potential contribution of natural selection and selectively neutral evolution to population divergence. We found 13 candidate loci, corresponding to 2.7% of loci, with signatures of divergent natural selection between alpine and lowland populations and between alpine populations (Fst  = 0.074-0.445 at outlier loci), but neutral population differentiation was also evident between alpine populations (FST  = 0.041-0.095 at neutral loci). By examining population structure at both neutral and outlier loci, we determined that the combined effects of selection and neutral evolution are associated with the divergence of alpine populations, which may be linked to extreme abiotic conditions and isolation between alpine sites. The presence of outlier levels of genetic variation in structured populations underscores the importance of separately analyzing neutral and outlier loci to infer the relative role of divergent natural selection and neutral evolution in population divergence.

  2. Natural selection and neutral evolution jointly drive population divergence between alpine and lowland ecotypes of the allopolyploid plant Anemone multifida (Ranunculaceae.

    Directory of Open Access Journals (Sweden)

    Jamie R McEwen

    Full Text Available Population differentiation can be driven in large part by natural selection, but selectively neutral evolution can play a prominent role in shaping patters of population divergence. The decomposition of the evolutionary history of populations into the relative effects of natural selection and selectively neutral evolution enables an understanding of the causes of population divergence and adaptation. In this study, we examined heterogeneous genomic divergence between alpine and lowland ecotypes of the allopolyploid plant, Anemone multifida. Using peak height and dominant AFLP data, we quantified population differentiation at non-outlier (neutral and outlier loci to determine the potential contribution of natural selection and selectively neutral evolution to population divergence. We found 13 candidate loci, corresponding to 2.7% of loci, with signatures of divergent natural selection between alpine and lowland populations and between alpine populations (Fst  = 0.074-0.445 at outlier loci, but neutral population differentiation was also evident between alpine populations (FST  = 0.041-0.095 at neutral loci. By examining population structure at both neutral and outlier loci, we determined that the combined effects of selection and neutral evolution are associated with the divergence of alpine populations, which may be linked to extreme abiotic conditions and isolation between alpine sites. The presence of outlier levels of genetic variation in structured populations underscores the importance of separately analyzing neutral and outlier loci to infer the relative role of divergent natural selection and neutral evolution in population divergence.

  3. Restricting wolves risks escape

    Science.gov (United States)

    Mech, L. David; Ballard, Warren; Bangs, Ed; Ream, Bob

    2010-01-01

    Implementing the proposal set forth by Licht and colleagues (BioScience 60: 147–153) requires restricting wolves to tiny "islands," areas that are magnitudes smaller than the ranges of most wolf populations. Wolves naturally have large ranges; restricting their spatial needs increases the risk of wolves escaping, exacerbating public relations and political and legal problems.

  4. Writing E/scapes

    Directory of Open Access Journals (Sweden)

    Jasmine Ulmer

    2017-12-01

    Full Text Available scape. 1 a brief ‘escape or means of escape’ 2 ‘a scenic view, whether of sea, land, or sky’ 3 ‘in its various senses’ 4 ‘a long flower-stalk rising directly from the root or rhizome’ 5 a theoretical approach to writing

  5. Escape From Cultural Isolation

    Science.gov (United States)

    Umesao, Tadao

    1975-01-01

    On the premise that the fundamental character of international interchange lies in a cruel and merciless collision of mutually suspicious and distrustful cultures, the historical resistance of the Japanese to cultural interchange is examined, the consequences of international trade without interchange noted, and the means of escape outlined. (JT)

  6. Escape from planetary neighbourhoods

    NARCIS (Netherlands)

    Waalkens, H.; Burbanks, A.; Wiggins, S.

    2005-01-01

    In this paper we use recently developed phase-space transport theory coupled with a so-called classical spectral theorem to develop a dynamically exact and computationally efficient procedure for studying escape from a planetary neighbourhood. The ‘planetary neighbourhood’ is a bounded region of

  7. Near-horizon Structure of Escape Zones of Electrically Charged Particles around Weakly Magnetized Rotating Black Hole

    Science.gov (United States)

    Kopáček, Ondřej; Karas, Vladimír

    2018-01-01

    An interplay of magnetic fields and gravitation drives accretion and outflows near black holes. However, a specific mechanism is still a matter of debate; it is very likely that different processes dominate under various conditions. In particular, for the acceleration of particles and their collimation in jets, an ordered component of the magnetic field seems to be essential. Here we discuss the role of large-scale magnetic fields in transporting the charged particles and dust grains from the bound orbits in the equatorial plane of a rotating (Kerr) black hole and the resulting acceleration along trajectories escaping the system in a direction parallel to the symmetry axis (perpendicular to the accretion disk). We consider a specific scenario of destabilization of circular geodesics of initially neutral matter by charging (e.g., due to photoionization). Some particles may be set on escaping trajectories and attain relativistic velocity. The case of charged particles differs from charged dust grains by their charge-to-mass ratio, but the acceleration mechanism operates in a similar manner. It appears that the chaotic dynamics controls the outflow and supports the formation of near-horizon escape zones. We employ the technique of recurrence plots to characterize the onset of chaos in the outflowing medium. We investigate the system numerically and construct the basin-boundary plots, which show the location and the extent of the escape zones. The effects of black hole spin and magnetic field strength on the formation and location of escape zones are discussed, and the maximal escape velocity is computed.

  8. Antibody escape kinetics of equine infectious anemia virus infection of horses.

    Science.gov (United States)

    Schwartz, Elissa J; Nanda, Seema; Mealey, Robert H

    2015-07-01

    Lentivirus escape from neutralizing antibodies (NAbs) is not well understood. In this work, we quantified antibody escape of a lentivirus, using antibody escape data from horses infected with equine infectious anemia virus. We calculated antibody blocking rates of wild-type virus, fitness costs of mutant virus, and growth rates of both viruses. These quantitative kinetic estimates of antibody escape are important for understanding lentiviral control by antibody neutralization and in developing NAb-eliciting vaccine strategies. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  9. Escape of Cosmic Rays from their Acceleration Sites

    Science.gov (United States)

    Malkov, Mikhail; Sagdeev, Roald; Diamond, Patrick

    2012-07-01

    The escape of cosmic rays (CR) from sites of their acceleration, such as supernova remnants (SNR), is calculated self-consistently with the CR transport suppression by self-excited Alfvén waves. The treatment uniformly applies both to the accelerator's nearby zone where intense CRs drive strong turbulence efficiently reducing their escape, and far zone where the CRs rapidly diffuse as test particles. To demonstrate the inseparability of the two zones in calculating the escape flux, an exact solution is obtained for the nonlinear spreading of a sharply localized CR cloud.

  10. Escape from the Alternative

    Directory of Open Access Journals (Sweden)

    Marin Dinu

    2006-12-01

    Full Text Available This paper sets out to elaborate on Romania’s specific agenda regarding the approach to the integration process in the EU as a project of modernization. The focus is on the functional aspects, the type of strategic solutions destined to consolidate the specific transformations belonging to post-communist transition seen as an internal transition, on the one hand and on the other hand to push convergence as the essence of integration, marked by the vision of EU integration as a continuation of change, which is the stage of external transition. Identifying the prominent factors and the pragmatic priorities of the escape from the peripheries of development by engaging in evolution by way of the second modernization constitutes as well a target for analysis. One particularity of the method of analysis is the review if the value-set of the bobsled effect of path dependency – the path of the peripheries – as well as of the set of values of the escape from the peripheries.

  11. Reconstructing the Alcatraz escape

    Science.gov (United States)

    Baart, F.; Hoes, O.; Hut, R.; Donchyts, G.; van Leeuwen, E.

    2014-12-01

    In the night of June 12, 1962 three inmates used a raft made of raincoatsto escaped the ultimate maximum security prison island Alcatraz in SanFrancisco, United States. History is unclear about what happened tothe escapees. At what time did they step into the water, did theysurvive, if so, where did they reach land? The fate of the escapees has been the subject of much debate: did theymake landfall on Angel Island, or did the current sweep them out ofthe bay and into the cold pacific ocean? In this presentation, we try to shed light on this historic case using avisualization of a high-resolution hydrodynamic simulation of the San Francisco Bay, combined with historical tidal records. By reconstructing the hydrodynamic conditions and using a particle based simulation of the escapees we show possible scenarios. The interactive model is visualized using both a 3D photorealistic and web based visualization. The "Escape from Alcatraz" scenario demonstrates the capabilities of the 3Di platform. This platform is normally used for overland flooding (1D/2D). The model engine uses a quad tree structure, resulting in an order of magnitude speedup. The subgrid approach takes detailed bathymetry information into account. The inter-model variability is tested by comparing the results with the DFlow Flexible Mesh (DFlowFM) San Francisco Bay model. Interactivity is implemented by converting the models from static programs to interactive libraries, adhering to the Basic ModelInterface (BMI). Interactive models are more suitable for answeringexploratory research questions such as this reconstruction effort. Although these hydrodynamic simulations only provide circumstantialevidence for solving the mystery of what happened during the foggy darknight of June 12, 1962, it can be used as a guidance and provides aninteresting testcase to apply interactive modelling.

  12. How does ionizing radiation escape from galaxies?

    Science.gov (United States)

    Orlitova, Ivana

    2016-10-01

    Search for sources that reionized the Universe from z 15 to z 6 is one of the main drivers of present-day astronomy. Low-mass star-forming galaxies are the most favoured sources of ionizing photons, but the searches of escaping Lyman continuum (LyC) have not been extremely successful. Our team has recently detected prominent LyC escape from five Green Pea galaxies at redshift 0.3, using the HST/COS spectrograph, which represents a significant breakthrough. We propose here to study the LyC escape of the strongest among these leakers, J1152, with spatial resolution. From the comparison of the ionizing and non-ionizing radiation maps, and surface brightness profiles, we will infer the major mode in which LyC is escaping: from the strongest starburst, from the galaxy edge, through a hole along our line-of-sight, through clumpy medium, or directly from all the production sites due to highly ionized medium in the entire galaxy. In parallel, we will test the predictive power of two highly debated indirect indicators of LyC leakage: the [OIII]5007/[OII]3727 ratio, and Lyman-alpha. We predict that their spatial distribution should closely follow that of the ionizing continuum if column densities of the neutral gas are low. This combined study, which relies on the HST unique capabilities, will bring crucial information on the structure of the leaking galaxies, provide constraints for hydrodynamic simulations, and will lead to efficient future searches for LyC leakers across a large range of redshifts.

  13. HIV Evolution and Escape.

    Science.gov (United States)

    Richman, Douglas D.; Little, Susan J.; Smith, Davey M.; Wrin, Terri; Petropoulos, Christos; Wong, Joseph K.

    2004-01-01

    Human immunodeficiency virus (HIV) exemplifies the principles of Darwinian evolution with a telescoped chronology. Because of its high mutation rate and remarkably high rates of replication, evolution can be appreciated over periods of days in contrast to the durations conceived of by Darwin. Certain selective pressures that drive the evolution of HIV include chemotherapy, anatomic compartmentalization and the immune response. Examples of these selective forces on HIV evolution are described. Images Fig. 5 PMID:17060974

  14. Quantum and thermal phase escape in extended Josephson systems

    Energy Technology Data Exchange (ETDEWEB)

    Kemp, A.

    2006-07-12

    In this work I examine phase escape in long annular Josephson tunnel junctions. The sine-Gordon equation governs the dynamics of the phase variable along the junction. This equation supports topological soliton solutions, which correspond to quanta of magnetic flux trapped in the junction barrier. For such Josephson vortices an effective potential is formed by an external magnetic field, while a bias current acts as a driving force. Both together form a metastable potential well, which the vortex is trapped in. When the driving force exceeds the pinning force of the potential, the vortex escapes and the junction switches to the voltage state. At a finite temperature the driving force fluctuates. If the junction's energy scale is small, the phase variable can undergo a macroscopic quantum tunneling (MQT) process at temperatures below the crossover temperature. Without a vortex trapped, the metastable state is not a potential minimum in space, but a potential minimum at zero phase difference. (orig.)

  15. Creating Engaging Escape Rooms for the Classroom

    Science.gov (United States)

    Nicholson, Scott

    2018-01-01

    Escape rooms are "live-action team-based games where players discover clues, solve puzzles, and accomplish tasks in one or more rooms in order to accomplish a specific goal (usually escaping from the room) in a limited amount of time." Escape Rooms are one type of Escape Game, which are narrative-based challenges that use puzzles, tasks,…

  16. Automated Escape Guidance Algorithms for An Escape Vehicle

    Science.gov (United States)

    Flanary, Ronald; Hammen, David; Ito, Daigoro; Rabalais, Bruce; Rishikof, Brian; Siebold, Karl

    2002-01-01

    An escape vehicle was designed to provide an emergency evacuation for crew members living on a space station. For maximum escape capability, the escape vehicle needs to have the ability to safely evacuate a station in a contingency scenario such as an uncontrolled (e.g., tumbling) station. This emergency escape sequence will typically be divided into three events: The fust separation event (SEP1), the navigation reconstruction event, and the second separation event (SEP2). SEP1 is responsible for taking the spacecraft from its docking port to a distance greater than the maximum radius of the rotating station. The navigation reconstruction event takes place prior to the SEP2 event and establishes the orbital state to within the tolerance limits necessary for SEP2. The SEP2 event calculates and performs an avoidance burn to prevent station recontact during the next several orbits. This paper presents the tools and results for the whole separation sequence with an emphasis on the two separation events. The fust challenge includes collision avoidance during the escape sequence while the station is in an uncontrolled rotational state, with rotation rates of up to 2 degrees per second. The task of avoiding a collision may require the use of the Vehicle's de-orbit propulsion system for maximum thrust and minimum dwell time within the vicinity of the station vicinity. The thrust of the propulsion system is in a single direction, and can be controlled only by the attitude of the spacecraft. Escape algorithms based on a look-up table or analytical guidance can be implemented since the rotation rate and the angular momentum vector can be sensed onboard and a-priori knowledge of the position and relative orientation are available. In addition, crew intervention has been provided for in the event of unforeseen obstacles in the escape path. The purpose of the SEP2 burn is to avoid re-contact with the station over an extended period of time. Performing this maneuver properly

  17. Lise Meitner's escape from Germany

    Science.gov (United States)

    Sime, Ruth Lewin

    1990-03-01

    Lise Meitner (1878-1968) achieved prominence as a nuclear physicist in Germany; although of Jewish origin, her Austrian citizenship exempted her from Nazi racial laws until the annexation of Austria in 1938 precipitated her dismissal. Forbidden to emigrate, she narrowly escaped to the Netherlands with the help of concerned friends in the international physics community.

  18. Escaping carbon lock-in

    International Nuclear Information System (INIS)

    Unruh, G.C.

    2002-01-01

    This article explores the climate policy implications of the arguments made in ''Understanding carbon lock-in'' (Unruh, 2000), which posited that industrial countries have become locked-into fossil fuel-based energy systems through path dependent processes driven by increasing returns to scale. Carbon lock-in arises through technological, organizational, social and institutional co-evolution, ''culminating'' in what was termed as techno-institutional complex (TIC). In order to resolve the climate problem, an escape from the lock-in condition is required. However, due to the self-referential nature of TIC, escape conditions are unlikely to be generated internally and it is argued here that erogenous forces are probably required. (author)

  19. The escape gated proportional counter

    International Nuclear Information System (INIS)

    Bibbo, G.; Sanford, P.W.

    1981-01-01

    Proportional counters, designed to detect hard X-rays, are generally filled with Xe or Kr or a mixture of Xe and Kr. In a large multichamber proportional counter the K-fluorescent radiation of these gases, which escapes the cell of origin, but is absorbed in other cells of the counter, provides an additional signal. A coincidence technique, which makes use of this signal to reduce the charged particle background and to correct the energy spectrum for the escape peak, has been evaluated. The detector has an improved energy resolution over that of the conventional proportional counter and preliminary results indicate that a reduction in the background by a factor of about 1000 can be obtained. Its combined properties of very efficient background reduction and improved energy resolution make this type of instrument most suitable for spectroscopic studies of astronomical X-ray sources in the energy range of 15-100 keV. (orig.)

  20. EscapED: A Framework for Creating Educational Escape Rooms and Interactive Games to For Higher/Further Education.

    Directory of Open Access Journals (Sweden)

    Samantha Jane Clarke

    2017-09-01

    Full Text Available Game-based learning (GBL is often found to be technologically driven and more often than not, serious games for instance, are conceptualised and designed solely for digital platforms and state of the art technologies. To encourage a greater discussion on the potential benefits and challenges of a more holistic approach to developing GBL that promote human centered interactions and play for learning, the authors present the escapED programme. The escapED programme was conceived following the recent entertainment trend of escape rooms and is used for developing non-digital GBL approaches within education. escapED aids the design and creation of educational Escape Rooms and Interactive Gaming Experiences for staff and students in further/higher education settings. The paper first presents a pilot study that was used to assess the feasibility and acceptance of University teaching staff of embedding interactive GBL into a higher education environment. The authors then present the escapED theoretical framework that was used to create the prototype game for the pilot study as a tool to aid future design and development of on-site interactive experiences. The paper also presents an external developer report of using the escapED framework to develop a prototype game for teaching research methods to Southampton University students. Finally, the authors present a discussion on the use of the escapED framework so far and plans for future work and evaluation in order to provide engaging alternatives for learning and soft skills development amongst higher education staff andstudents.

  1. Malaria parasites: the great escape

    Directory of Open Access Journals (Sweden)

    Laurent Rénia

    2016-11-01

    Full Text Available Parasites of the genus Plasmodium have a complex life cycle. They alternate between their final mosquito host and their intermediate hosts. The parasite can be either extra- or intracellular, depending on the stage of development. By modifying their shape, motility, and metabolic requirements, the parasite adapts to the different environments in their different hosts. The parasite has evolved to escape the multiple immune mechanisms in the host that try to block parasite development at the different stages of their development. In this article, we describe the mechanisms reported thus far that allow the Plasmodium parasite to evade innate and adaptive immune responses.

  2. Dementia & Driving

    Science.gov (United States)

    ... find the loss of driving privileges and the inherent loss of independence upsetting. Encourage the individual with ... to modify their driving. This can reduce the risk of an accident if the individual’s driving skills ...

  3. Drive Stands

    Data.gov (United States)

    Federal Laboratory Consortium — The Electrical Systems Laboratory (ESL)houses numerous electrically driven drive stands. A drive stand consists of an electric motor driving a gearbox and a mounting...

  4. Generalized Jeans' Escape of Pick-Up Ions in Quasi-Linear Relaxation

    Science.gov (United States)

    Moore, T. E.; Khazanov, G. V.

    2011-01-01

    Jeans escape is a well-validated formulation of upper atmospheric escape that we have generalized to estimate plasma escape from ionospheres. It involves the computation of the parts of particle velocity space that are unbound by the gravitational potential at the exobase, followed by a calculation of the flux carried by such unbound particles as they escape from the potential well. To generalize this approach for ions, we superposed an electrostatic ambipolar potential and a centrifugal potential, for motions across and along a divergent magnetic field. We then considered how the presence of superthermal electrons, produced by precipitating auroral primary electrons, controls the ambipolar potential. We also showed that the centrifugal potential plays a small role in controlling the mass escape flux from the terrestrial ionosphere. We then applied the transverse ion velocity distribution produced when ions, picked up by supersonic (i.e., auroral) ionospheric convection, relax via quasi-linear diffusion, as estimated for cometary comas [1]. The results provide a theoretical basis for observed ion escape response to electromagnetic and kinetic energy sources. They also suggest that super-sonic but sub-Alfvenic flow, with ion pick-up, is a unique and important regime of ion-neutral coupling, in which plasma wave-particle interactions are driven by ion-neutral collisions at densities for which the collision frequency falls near or below the gyro-frequency. As another possible illustration of this process, the heliopause ribbon discovered by the IBEX mission involves interactions between the solar wind ions and the interstellar neutral gas, in a regime that may be analogous [2].

  5. Submarine 'safe to escape' studies in man.

    Science.gov (United States)

    Jurd, K M; Seddon, F M; Thacker, J C; Blogg, S L; Stansfield, M R D; White, M G; Loveman, G A M

    2014-01-01

    The Royal Navy requires reliable advice on the safe limits of escape from a distressed submarine (DISSUB). Flooding in a DISSUB may cause a rise in ambient pressure, increasing the risk of decompression sickness (DCS) and decreasing the maximum depth from which it is safe to escape. The aim of this study was to investigate the pressure/depth limits to escape following saturation at raised ambient pressure. Exposure to saturation pressures up to 1.6 bar (a) (160 kPa) (n = 38); escapes from depths down to 120 meters of sea water (msw) (n = 254) and a combination of saturation followed by escape (n = 90) was carried out in the QinetiQ Submarine Escape Simulator, Alverstoke, United Kingdom. Doppler ultrasound monitoring was used to judge the severity of decompression stress. The trials confirmed the previously untested advice, in the Guardbook, that if a DISSUB was lying at a depth of 90 msw, then it was safe to escape when the pressure in the DISSUB was 1.5 bar (a), but also indicated that this advice may be overly conservative. This study demonstrated that the upper DISSUB saturation pressure limit to safe escape from 90 msw was 1.6 bar (a), resulting in two cases of DCS.

  6. Escape of atmospheric gases from the Moon

    Indian Academy of Sciences (India)

    The escape rate of atmospheric molecules on the Moon is calculated.Based on the assumption that the rates of emission and escape of gases attain equilibrium, the ratio of molecular number densities during day and night, 0/0, can be explained. The plausible emission rate of helium and radioactive elements present ...

  7. Escape of atmospheric gases from the Moon

    Indian Academy of Sciences (India)

    its weak gravity, the atmospheric molecules gradu- ally escaped, resulting in the very thin atmosphere existing now. To see if a thick atmosphere could be retained or not, we assume that the air hav- ing pressure of 1atmosphere (as exists on Earth now) existed on the Moon initially and calculate the escape life times for ...

  8. Two examples of escaping harmonic maps

    International Nuclear Information System (INIS)

    Pereira do Valle, A.; Verjovsky, A.

    1988-12-01

    This paper is part of a study on the existence of special harmonic maps on complete non-compact Riemannian manifolds. We generalize the notion of escaping geodesic and prove some results on the existence of escaping harmonic maps. 11 refs, 6 figs

  9. Escaping Homelessness: Anticipated and Perceived Facilitators

    Science.gov (United States)

    Patterson, Allisha; Tweed, Roger

    2009-01-01

    One study with two distinct sections was conducted to identify factors facilitating escape from homelessness. In Section 1, 58 homeless individuals rated possible facilitators of escape (factors they believed would help them become more independent and self-sufficient). In Section 2, 80 participants who had already exited homelessness rated the…

  10. Learning from escaped prescribed fire reviews [Abstract

    Science.gov (United States)

    Anne Black; Dave Thomas; James Saveland

    2011-01-01

    Over the past decade, the wildland fire community has developed a number of innovative methods for conducting a review following escape of a prescribed fire. The stated purpose been to identify methods that not only meet policy requirements, but to reduce future escapes. Implicit is the assumption that a review leads to learning. Yet, as organizational learning expert...

  11. Feline immunodeficiency virus (FIV) neutralization: a review.

    Science.gov (United States)

    Hosie, Margaret J; Pajek, Daniela; Samman, Ayman; Willett, Brian J

    2011-10-01

    One of the major obstacles that must be overcome in the design of effective lentiviral vaccines is the ability of lentiviruses to evolve in order to escape from neutralizing antibodies. The primary target for neutralizing antibodies is the highly variable viral envelope glycoprotein (Env), a glycoprotein that is essential for viral entry and comprises both variable and conserved regions. As a result of the complex trimeric nature of Env, there is steric hindrance of conserved epitopes required for receptor binding so that these are not accessible to antibodies. Instead, the humoral response is targeted towards decoy immunodominant epitopes on variable domains such as the third hypervariable loop (V3) of Env. For feline immunodeficiency virus (FIV), as well as the related human immunodeficiency virus-1 (HIV-1), little is known about the factors that lead to the development of broadly neutralizing antibodies. In cats infected with FIV and patients infected with HIV-1, only rarely are plasma samples found that contain antibodies capable of neutralizing isolates from other clades. In this review we examine the neutralizing response to FIV, comparing and contrasting with the response to HIV. We ask whether broadly neutralizing antibodies are induced by FIV infection and discuss the comparative value of studies of neutralizing antibodies in FIV infection for the development of more effective vaccine strategies against lentiviral infections in general, including HIV-1.

  12. Feline Immunodeficiency Virus (FIV Neutralization: A Review

    Directory of Open Access Journals (Sweden)

    Margaret J. Hosie

    2011-10-01

    Full Text Available One of the major obstacles that must be overcome in the design of effective lentiviral vaccines is the ability of lentiviruses to evolve in order to escape from neutralizing antibodies. The primary target for neutralizing antibodies is the highly variable viral envelope glycoprotein (Env, a glycoprotein that is essential for viral entry and comprises both variable and conserved regions. As a result of the complex trimeric nature of Env, there is steric hindrance of conserved epitopes required for receptor binding so that these are not accessible to antibodies. Instead, the humoral response is targeted towards decoy immunodominant epitopes on variable domains such as the third hypervariable loop (V3 of Env. For feline immunodeficiency virus (FIV, as well as the related human immunodeficiency virus-1 (HIV-1, little is known about the factors that lead to the development of broadly neutralizing antibodies. In cats infected with FIV and patients infected with HIV-1, only rarely are plasma samples found that contain antibodies capable of neutralizing isolates from other clades. In this review we examine the neutralizing response to FIV, comparing and contrasting with the response to HIV. We ask whether broadly neutralizing antibodies are induced by FIV infection and discuss the comparative value of studies of neutralizing antibodies in FIV infection for the development of more effective vaccine strategies against lentiviral infections in general, including HIV-1.

  13. Noninductive current drive in tokamaks

    International Nuclear Information System (INIS)

    Uckan, N.A.

    1985-01-01

    Various current drive mechanisms may be grouped into four classes: (1) injection of energetic particle beams; (2) launching of rf waves; (3) hybrid schemes, which are combinations of various rf schemes (rf plus beams, rf and/or beam plus ohmic heating, etc.); and (4) other schemes, some of which are specific to reactor plasma conditions requiring the presence of alpha particle or intense synchrotron radiation. Particle injection schemes include current drive by neutral beams and relativistic electron beams. The rf schemes include current drive by the lower hybrid (LH) waves, the electron waves, the waves in the ion cyclotron range of frequencies, etc. Only a few of these approaches, however, have been tested experimentally, with the broadest data base available for LH waves. Included in this report are (1) efficiency criteria for current drive, (2) current drive by neutral beam injection, (3) LH current drive, (4) electron cyclotron current drive, (5) current drive by ion cyclotron waves - minority species heating, and (6) current drive by other schemes (such as hybrids and low frequency waves)

  14. Physics escape room as an educational tool

    Science.gov (United States)

    Vörös, Alpár István Vita; Sárközi, Zsuzsa

    2017-12-01

    Escape rooms have flourished in the last decade. These are adventure games in which players work together to solve puzzles using hints, clues and a strategy to escape from a locked room. In many cases they use different phenomena related to physics. Hence the idea of using escape rooms in science centers or even in classroom activities. Escape rooms are designed for one single team of players, the method is more suitable for activities in a science centre. In our paper, we show that escape rooms' puzzle solving methods could be used in physics classroom activities as well, taking into account that several teams have to work together in the same room/place. We have developed an educational escape game for physics of fluids, as this topic is left out from the Romanian high-school curriculum. We have tried out our game during the project week called "Şcoala altfel" ("school in a different way") and in a physics camp for gifted students. We present the designed physics escape game and the results.

  15. A Model for SEP Escape

    Science.gov (United States)

    Antiochos, S. K.; Masson, S.; DeVore, C. R.

    2012-01-01

    Magnetic reconnection in the solar atmosphere is believed to be the driver of most solar explosive phenomena. Therefore, the topology of the coronal magnetic field is central to understanding the solar drivers of space weather. Of particular importance to space weather are the impulsive Solar Energetic particles that are associated with some CME/eruptive flare events. Observationally, the magnetic configuration of active regions where solar eruptions originate appears to agree with the standard eruptive flare model. According to this model, particles accelerated at the flare reconnection site should remain trapped in the corona and the ejected plasmoid. However, flare-accelerated particles frequently reach the Earth long before the CME does. We present a model that may account for the injection of energetic particles onto open magnetic flux tubes connecting to the Earth. Our model is based on the well-known 2.5D breakout topology, which has a coronal null point (null line) and a four-flux system. A key new addition, however, is that we include an isothermal solar wind with open-flux regions. Depending on the location of the open flux with respect to the null point, we find that the flare reconnection can consist of two distinct phases. At first, the flare reconnection involves only closed field, but if the eruption occurs close to the open field, we find a second phase involving interchange reconnection between open and closed. We argue that this second reconnection episode is responsible for the injection of flare-accelerated particles into the interplanetary medium. We will report on our recent work toward understanding how flare particles escape to the heliosphere. This work uses high-resolution 2.5D MHD numerical simulations performed with the Adaptively Refined MHD Solver (ARMS).

  16. What is Neutrality?

    NARCIS (Netherlands)

    Pierik, R.; van der Burg, W.

    2014-01-01

    This paper reinvestigates the question of liberal neutrality. We contend that current liberal discussions have been dominated - if not hijacked - by one particular interpretation of what neutrality could imply, namely, exclusive neutrality, that aims to exclude religious and cultural expressions

  17. Electric drives

    CERN Document Server

    Boldea, Ion

    2005-01-01

    ENERGY CONVERSION IN ELECTRIC DRIVESElectric Drives: A DefinitionApplication Range of Electric DrivesEnergy Savings Pay Off RapidlyGlobal Energy Savings Through PEC DrivesMotor/Mechanical Load MatchMotion/Time Profile MatchLoad Dynamics and StabilityMultiquadrant OperationPerformance IndexesProblemsELECTRIC MOTORS FOR DRIVESElectric Drives: A Typical ConfigurationElectric Motors for DrivesDC Brush MotorsConventional AC MotorsPower Electronic Converter Dependent MotorsEnergy Conversion in Electric Motors/GeneratorsPOWER ELECTRONIC CONVERTERS (PECs) FOR DRIVESPower Electronic Switches (PESs)The

  18. Escape dynamics: a continuous-time approximation

    Czech Academy of Sciences Publication Activity Database

    Kolyuzhnov, D.; Bogomolova, A.; Slobodyan, Sergey

    2014-01-01

    Roč. 38, January (2014), s. 161-183 ISSN 0165-1889 Institutional support: RVO:67985998 Keywords : constant gain adaptive learning * escape dynamics * recursive least squares Subject RIV: AH - Economics Impact factor: 1.018, year: 2014

  19. Non-thermal escape rates of atmospheric H and D from Mars using MAVEN data

    Science.gov (United States)

    Gacesa, M.; Zahnle, K. J.

    2017-12-01

    Geological evidence suggests that an ocean of liquid water existed on Mars until at least middle to late Noachian era (4.1 to 3.8 Ga) and possibly, at least episodically, as late as Hesperian. Between 67% and 87% of the total primordial amount of water, equal to about 70 to 110 meters equivalent (spread over the entire Mars' surface), is believed to have escape to space, while about 35 meters remains on or beneath the surface as water ice. Establishing better constraints on these numbers and identifying the responsible atmospheric loss processes remains the major objective of NASA's Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. The ratio of atmospheric Deuterium and Hydrogen (D/H) on Mars is one of the best indicators of water loss to space. While majority of H and D escape through thermal Jeans escape, up to 10% of D can escape to space via non-thermal mechanisms, such as collisions with superthermal neutral atoms. In this study, we present new estimates of non-thermal escape rates of light molecules of interest to the water evolution, including H2, HD, OH, and OD, based on recent measurements of atmospheric density and temperature profiles by MAVEN. The escape mechanisms considered include photochemical sources of hot O, as well as collisions with energetic neutral atoms produced in charge-exchange of solar wind ions with atmospheric gases1,2. Energy transport and escape rates are modeled using quantum reactive scattering formalism3 and seasonal variations are illustrated. Finally, a simple estimate of the role of the non-thermal escape mechanisms in previous eras is given. We conclude that D escape rates can be affected by the non-thermal processes with consequences on the estimates of primordial water inventory based on the D/H ratio. [1] N. Lewkow and V. Kharchenko, Astroph. J., 790, 98 (2014) [2] M. Gacesa, N. Lewkow, V. Kharchenko, Icarus 284, 90 (2017) [3] M. Gacesa and V. Kharchenko, Geophys. Res. Lett., 39, L10203 (2012)

  20. St.Petersburg Escape Experience Tour

    OpenAIRE

    Palagina, Mariia; Zhak, Svetlana

    2017-01-01

    The growing popularity of Russia as a tourist destination and the high interest towards escape rooms and quests opens new business opportunities and market niches. The aim of this thesis is to develop a tourist product based on the new escape room tourism concept combining the historical, cultural and game experiences. The choice of the theme and destination was determined by the authors’ personal backgrounds and the destination proximity to Finland. The theoretical research was implement...

  1. The escape problem for mortal walkers

    OpenAIRE

    Grebenkov, D. S.; Rupprecht, J. -F.

    2016-01-01

    We introduce and investigate the escape problem for random walkers that may eventually die, decay, bleach, or lose activity during their diffusion towards an escape or reactive region on the boundary of a confining domain. In the case of a first-order kinetics (i.e., exponentially distributed lifetimes), we study the effect of the associated death rate onto the survival probability, the exit probability, and the mean first passage time. We derive the upper and lower bounds and some approximat...

  2. Potential Effects of Permanent Neutrality on Mongolia’s Defense Foreign Cooperation

    Science.gov (United States)

    2016-09-01

    and provided broad intelligence for the Allies, and Sweden provided arms and military equipment for Norway to fight alongside the Soviet Union.36...more duties for the neutral states to affirm the safety of war victims such as prisoners of war, escaped prisoners of war, and internees, including...of war to protect military prisoners , 71 Karsh, Neutrality and Small States, 38. 72 Karsh

  3. Submarine tower escape decompression sickness risk estimation.

    Science.gov (United States)

    Loveman, G A M; Seddon, E M; Thacker, J C; Stansfield, M R; Jurd, K M

    2014-01-01

    Actions to enhance survival in a distressed submarine (DISSUB) scenario may be guided in part by knowledge of the likely risk of decompression sickness (DCS) should the crew attempt tower escape. A mathematical model for DCS risk estimation has been calibrated against DCS outcome data from 3,738 exposures of either men or goats to raised pressure. Body mass was used to scale DCS risk. The calibration data included more than 1,000 actual or simulated submarine escape exposures and no exposures with substantial staged decompression. Cases of pulmonary barotrauma were removed from the calibration data. The calibrated model was used to estimate the likelihood of DCS occurrence following submarine escape from the United Kingdom Royal Navy tower escape system. Where internal DISSUB pressure remains at - 0.1 MPa, escape from DISSUB depths 60% DCS risk predicted for a 200-meter escape from saturation at 0.21 MPa. Using the calibrated model to predict DCS for direct ascent from saturation gives similar risk estimates to other published models.

  4. Polymer escape from a confining potential

    International Nuclear Information System (INIS)

    Mökkönen, Harri; Ikonen, Timo; Jónsson, Hannes; Ala-Nissila, Tapio

    2014-01-01

    The rate of escape of polymers from a two-dimensionally confining potential well has been evaluated using self-avoiding as well as ideal chain representations of varying length, up to 80 beads. Long timescale Langevin trajectories were calculated using the path integral hyperdynamics method to evaluate the escape rate. A minimum is found in the rate for self-avoiding polymers of intermediate length while the escape rate decreases monotonically with polymer length for ideal polymers. The increase in the rate for long, self-avoiding polymers is ascribed to crowding in the potential well which reduces the free energy escape barrier. An effective potential curve obtained using the centroid as an independent variable was evaluated by thermodynamic averaging and Kramers rate theory then applied to estimate the escape rate. While the qualitative features are well reproduced by this approach, it significantly overestimates the rate, especially for the longer polymers. The reason for this is illustrated by constructing a two-dimensional effective energy surface using the radius of gyration as well as the centroid as controlled variables. This shows that the description of a transition state dividing surface using only the centroid fails to confine the system to the region corresponding to the free energy barrier and this problem becomes more pronounced the longer the polymer is. A proper definition of a transition state for polymer escape needs to take into account the shape as well as the location of the polymer

  5. Broadening of neutralization activity to directly block a dominant antibody-driven SARS-coronavirus evolution pathway.

    Directory of Open Access Journals (Sweden)

    Jianhua Sui

    2008-11-01

    Full Text Available Phylogenetic analyses have provided strong evidence that amino acid changes in spike (S protein of animal and human SARS coronaviruses (SARS-CoVs during and between two zoonotic transfers (2002/03 and 2003/04 are the result of positive selection. While several studies support that some amino acid changes between animal and human viruses are the result of inter-species adaptation, the role of neutralizing antibodies (nAbs in driving SARS-CoV evolution, particularly during intra-species transmission, is unknown. A detailed examination of SARS-CoV infected animal and human convalescent sera could provide evidence of nAb pressure which, if found, may lead to strategies to effectively block virus evolution pathways by broadening the activity of nAbs. Here we show, by focusing on a dominant neutralization epitope, that contemporaneous- and cross-strain nAb responses against SARS-CoV spike protein exist during natural infection. In vitro immune pressure on this epitope using 2002/03 strain-specific nAb 80R recapitulated a dominant escape mutation that was present in all 2003/04 animal and human viruses. Strategies to block this nAb escape/naturally occurring evolution pathway by generating broad nAbs (BnAbs with activity against 80R escape mutants and both 2002/03 and 2003/04 strains were explored. Structure-based amino acid changes in an activation-induced cytidine deaminase (AID "hot spot" in a light chain CDR (complementarity determining region alone, introduced through shuffling of naturally occurring non-immune human VL chain repertoire or by targeted mutagenesis, were successful in generating these BnAbs. These results demonstrate that nAb-mediated immune pressure is likely a driving force for positive selection during intra-species transmission of SARS-CoV. Somatic hypermutation (SHM of a single VL CDR can markedly broaden the activity of a strain-specific nAb. The strategies investigated in this study, in particular the use of structural

  6. Antibody neutralization of retargeted measles viruses

    Science.gov (United States)

    Lech, Patrycja J.; Pappoe, Roland; Nakamura, Takafumi; Tobin, Gregory J.; Nara, Peter L.; Russell, Stephen J.

    2014-01-01

    The measles virus (MV) vaccine lineage is a promising oncolytic but prior exposure to the measles vaccine or wild-type MV strains limits treatment utility due to the presence of anti-measles antibodies. MV entry can be redirected by displaying a polypeptide ligand on the Hemagglutinin (H) C-terminus. We hypothesized that retargeted MV would escape neutralization by monoclonal antibodies (mAbs) recognizing the H receptor-binding surface and be less susceptible to neutralization by human antisera. Using chimeric H proteins, with and without mutations that ablate MV receptor binding, we show that retargeted MVs escape mAbs that target the H receptor-binding surface by virtue of mutations that ablate infection via SLAM and CD46. However, C-terminally displayed domains do not mediate virus entry in the presence of human antibodies that bind to the underlying H domain. In conclusion, utility of retargeted oncolytic measles viruses does not extend to evasion of human serum neutralization. PMID:24725950

  7. Radon escape from New Zealand speleothems

    International Nuclear Information System (INIS)

    Lyons, R.G.; Crossley, P.C.; Ditchburn, R.G.; McCabe, W.J.; Whitehead, N.

    1989-01-01

    When calculating the environment radiation absorbed dose rate in ESR or TL dating, it is usual to allow for the possibility of disequilibrium in the uranium-series decay chain, due to the escape of radon from the sample. A number of speleothems from a temperate climate, varying in age have been analysed for thorium and polonium isotopes. A comparison of thorium and polonium activities with the expected values, derived from the age of the sample and the initial concentrations, gives an estimate of the radon escape. The recovery rates of uranium and thorium were monitored by spiking but the recovery rate of polonium must be regarded as a minimum; estimates of radon escape are therefore likely to be overestimates. Of 19 speleothems studied, only two gave results inconsistent with values predicted on the basis of no radon loss one, a relatively young sample, showed evidence of radium coprecipitation with uranium, and one, a dog-tooth spar with an open crystal structure and a high porosity showed evidence for radon escape. A third sample, also a flowstone/spar with a higher porosity than normal, was marginally significant. As the degree of radon escape will vary from sample to sample, the environment dose rate must be regarded as having a high level of uncertainty for samples of this type, unless radon escape is determined experimentally. The remaining samples (12 stalagmites, 3 stalactites and 1 flowstone), of a more massive structure, showed no significant radon escape and therefore the environment dose rate for such samples should be calculated on the basis of radon retention. (author)

  8. Radon escape from New Zealand speleothems

    Energy Technology Data Exchange (ETDEWEB)

    Lyons, R.G.; Crossley, P.C. (Auckland Univ. (New Zealand). Dept. of Geography); Ditchburn, R.G.; McCabe, W.J.; Whitehead, N. (Department of Scientific and Industrial Research, Lower Hutt (New Zealand). Inst. of Nuclear Sciences)

    1989-01-01

    When calculating the environment radiation absorbed dose rate in ESR or TL dating, it is usual to allow for the possibility of disequilibrium in the uranium-series decay chain, due to the escape of radon from the sample. A number of speleothems from a temperate climate, varying in age have been analysed for thorium and polonium isotopes. A comparison of thorium and polonium activities with the expected values, derived from the age of the sample and the initial concentrations, gives an estimate of the radon escape. The recovery rates of uranium and thorium were monitored by spiking but the recovery rate of polonium must be regarded as a minimum; estimates of radon escape are therefore likely to be overestimates. Of 19 speleothems studied, only two gave results inconsistent with values predicted on the basis of no radon loss one, a relatively young sample, showed evidence of radium coprecipitation with uranium, and one, a dog-tooth spar with an open crystal structure and a high porosity showed evidence for radon escape. A third sample, also a flowstone/spar with a higher porosity than normal, was marginally significant. As the degree of radon escape will vary from sample to sample, the environment dose rate must be regarded as having a high level of uncertainty for samples of this type, unless radon escape is determined experimentally. The remaining samples (12 stalagmites, 3 stalactites and 1 flowstone), of a more massive structure, showed no significant radon escape and therefore the environment dose rate for such samples should be calculated on the basis of radon retention. (author).

  9. ITER Neutral Beam Injection System

    International Nuclear Information System (INIS)

    Ohara, Yoshihiro; Tanaka, Shigeru; Akiba, Masato

    1991-03-01

    A Japanese design proposal of the ITER Neutral Beam Injection System (NBS) which is consistent with the ITER common design requirements is described. The injection system is required to deliver a neutral deuterium beam of 75MW at 1.3MeV to the reactor plasma and utilized not only for plasma heating but also for current drive and current profile control. The injection system is composed of 9 modules, each of which is designed so as to inject a 1.3MeV, 10MW neutral beam. The most important point in the design is that the injection system is based on the utilization of a cesium-seeded volume negative ion source which can produce an intense negative ion beam with high current density at a low source operating pressure. The design value of the source is based on the experimental values achieved at JAERI. The utilization of the cesium-seeded volume source is essential to the design of an efficient and compact neutral beam injection system which satisfies the ITER common design requirements. The critical components to realize this design are the 1.3MeV, 17A electrostatic accelerator and the high voltage DC acceleration power supply, whose performances must be demonstrated prior to the construction of ITER NBI system. (author)

  10. Thermal escape from extrasolar giant planets.

    Science.gov (United States)

    Koskinen, Tommi T; Lavvas, Panayotis; Harris, Matthew J; Yelle, Roger V

    2014-04-28

    The detection of hot atomic hydrogen and heavy atoms and ions at high altitudes around close-in extrasolar giant planets (EGPs) such as HD209458b implies that these planets have hot and rapidly escaping atmospheres that extend to several planetary radii. These characteristics, however, cannot be generalized to all close-in EGPs. The thermal escape mechanism and mass loss rate from EGPs depend on a complex interplay between photochemistry and radiative transfer driven by the stellar UV radiation. In this study, we explore how these processes change under different levels of irradiation on giant planets with different characteristics. We confirm that there are two distinct regimes of thermal escape from EGPs, and that the transition between these regimes is relatively sharp. Our results have implications for thermal mass loss rates from different EGPs that we discuss in the context of currently known planets and the detectability of their upper atmospheres.

  11. Martian Atmospheric and Ionospheric plasma Escape

    Science.gov (United States)

    Lundin, Rickard

    2016-04-01

    Solar forcing is responsible for the heating, ionization, photochemistry, and erosion processes in the upper atmosphere throughout the lifetime of the terrestrial planets. Of the four terrestrial planets, the Earth is the only one with a fully developed biosphere, while our kin Venus and Mars have evolved into arid inhabitable planets. As for Mars, there are ample evidences for an early Noachian, water rich period on Mars. The question is, what made Mars evolve so differently compared to the Earth? Various hydrosphere and atmospheric evolution scenarios for Mars have been forwarded based on surface morphology, chemical composition, simulations, semi-empiric (in-situ data) models, and the long-term evolution of the Sun. Progress has been made, but the case is still open regarding the changes that led to the present arid surface and tenuous atmosphere at Mars. This presentation addresses the long-term variability of the Sun, the solar forcing impact on the Martian atmosphere, and its interaction with the space environment - an electromagnetic wave and particle interaction with the upper atmosphere that has implications for its photochemistry, composition, and energization that governs thermal and non-thermal escape. Non-thermal escape implies an electromagnetic upward energization of planetary ions and molecules to velocities above escape velocity, a process governed by a combination of solar EUV radiation (ionization), and energy and momentum transfer by the solar wind. The ion escape issue dates back to the early Soviet and US-missions to Mars, but the first more accurate estimates of escape rates came with the Phobos-2 mission in 1989. Better-quality ion composition measurement results of atmospheric/ionospheric ion escape from Mars, obtained from ESA Mars Express (MEX) instruments, have improved our understanding of the ion escape mechanism. With the NASA MAVEN spacecraft orbiting Mars since Sept. 2014, dual in-situ measurement with plasma instruments are now

  12. CANCER Escape from senescence boosts tumour growth

    NARCIS (Netherlands)

    Medema, Jan Paul

    2018-01-01

    Some chemotherapies block cancer growth by driving tumour cells into a state of cell-division arrest termed senescence. It emerges that such cells have a boosted capacity to drive tumour growth if they exit senescence

  13. Neutral Buoyancy Laboratory (NBL)

    Data.gov (United States)

    Federal Laboratory Consortium — The Neutral Buoyancy Laboratory (NBL) is an astronaut training facility and neutral buoyancy pool operated by NASA and located at the Sonny Carter Training Facility,...

  14. Drowsy Driving

    Science.gov (United States)

    ... at least 8 hours. 8-9 Develop good sleeping habits such as sticking to a sleep schedule. If ... K, Howard ME. Cognitive components of simulated driving performance: sleep loss effects and predictors. Accid Anal Prev. 2012; ...

  15. Distracted Driving

    Science.gov (United States)

    ... Communities Toolkit Best Practices Guide Publications Motorcycle Safety Bicycle Safety Publications Global Road Safety Get Email Updates ... study. The Insurance Institute for Highway Safety keeps track of distracted driving laws. 7 As of June ...

  16. Nociception and escape behavior in planarians

    Science.gov (United States)

    Schoetz Collins, Eva-Maria

    2015-03-01

    Planarians are famous and widely studied for their regenerative capabilities. When a moving planarian is cut through the middle, the resulting head and tail pieces instantaneously retract and exhibit a characteristic escape response that differs from normal locomotion. In asexual animals, a similar reaction is observed when the planarian undergoes fission, suggesting that reproduction through self-tearing is a rather traumatic event for the animal. Using a multiscale approach, we unravel the dynamics, mechanics, and functional aspects of the planarian escape response. This musculature-driven gait was found to be a dominating response that supersedes the urge to feed or reproduce and quantitatively differs from other modes of planarian locomotion (gliding, peristalsis). We show that this escape gait constitutes the animal's pain response mediated by TRP like receptors and the neurotransmitter histamine, and that it can be induced through adverse thermal, mechanical, electrical or chemical stimuli. Ultimately, we will examine the neuronal subpopulations involved in mediating escape reflexes in planarians and how they are functionally restored during regeneration, thereby gaining mechanistic insight into the neuronal circuits required for specific behaviors. Supported by BWF CASI and Sloan Foundation.

  17. Pade approximant calculations for neutron escape probability

    International Nuclear Information System (INIS)

    El Wakil, S.A.; Saad, E.A.; Hendi, A.A.

    1984-07-01

    The neutron escape probability from a non-multiplying slab containing internal source is defined in terms of a functional relation for the scattering function for the diffuse reflection problem. The Pade approximant technique is used to get numerical results which compare with exact results. (author)

  18. How do biological systems escape 'chaotic' state?

    Indian Academy of Sciences (India)

    B J Rao

    2018-02-13

    Feb 13, 2018 ... triggering 'escape from homeostasis' (Nijhout et al. 2014) where phenotypes begin to become less stable and eventually turn into fully unstable state, the start of 'chaos' in a system. Therefore, the key to biological designs is to stay close to or within the 'homeostatic plateau' and resist drifting into 'chaos'.

  19. Escape dynamics: a continuous-time approximation

    Czech Academy of Sciences Publication Activity Database

    Kolyuzhnov, Dmitri; Bogomolova, Anna; Slobodyan, S.

    2014-01-01

    Roč. 38, January (2014), s. 161-183 ISSN 0165-1889 R&D Projects: GA ČR(CZ) GBP402/12/G097 Institutional support: PRVOUK-P23 Keywords : constant gain adaptive learning * escape dynamics * recursive least squares Subject RIV: AH - Economics Impact factor: 1.018, year: 2014

  20. Net escapement of Antartic krill in trawls

    DEFF Research Database (Denmark)

    Krafft, B.A.; Krag, Ludvig Ahm; Herrmann, Bent

    This document describes the aims and methodology of a three year project (commenced in 2012) entitled Net Escapement of Antarctic krill in Trawls (NEAT). The study will include a morphology based mathematical modeling (FISHSELECT) of different sex and maturity groups of Antarctic krill (Euphausia...

  1. Escape dynamics: a continuous-time approximation

    Czech Academy of Sciences Publication Activity Database

    Kolyuzhnov, Dmitri; Bogomolova, Anna; Slobodyan, Sergey

    -, č. 285 (2006), s. 1-42 ISSN 1211-3298 Institutional research plan: CEZ:AV0Z70850503 Keywords : escape dynamics * constant gain adaptive learning * large deviations theory Subject RIV: AH - Economics http://www.cerge-ei.cz/pdf/wp/Wp285.pdf

  2. Centrifugally Stimulated Exospheric Ion Escape at Mercury

    Science.gov (United States)

    Delcourt, Dominique; Seki, K.; Terada, N.; Moore, Thomas E.

    2012-01-01

    We investigate the transport of ions in the low-altitude magnetosphere magnetosphere of Mercury. We show that, because of small spatial scales, the centrifugal effect due to curvature of the E B drift paths can lead to significant particle energization in the parallel direction. We demonstrate that because of this effect, ions with initial speed smaller than the escape speed such as those produced via thermal desorption can overcome gravity and escape into the magnetosphere. The escape route of this low-energy exosphere originating material is largely controlled by the magnetospheric convection rate. This escape route spreads over a narrower range of altitudes when the convection rate increases. Bulk transport of low-energy planetary material thus occurs within a limited region of space once moderate magnetospheric convection is established. These results suggest that, via release of material otherwise gravitationally trapped, the E B related centrifugal acceleration is an important mechanism for the net supply of plasma to the magnetosphere of Mercury.

  3. Learning from escaped prescribed fire reviews

    Science.gov (United States)

    Anne E. Black; Dave Thomas; James Saveland; Jennifer D. Ziegler

    2011-01-01

    The U.S. wildland fire community has developed a number of innovative methods for conducting a review following escape of a prescribed fire (expanding on the typical regional or local reviews, to include more of a learning focus - expanded After Action Reviews, reviews that incorporate High Reliability Organizing, Facilitated Learning Analyses, etc). The stated purpose...

  4. Escape driven by α -stable white noises

    Science.gov (United States)

    Dybiec, B.; Gudowska-Nowak, E.; Hänggi, P.

    2007-02-01

    We explore the archetype problem of an escape dynamics occurring in a symmetric double well potential when the Brownian particle is driven by white Lévy noise in a dynamical regime where inertial effects can safely be neglected. The behavior of escaping trajectories from one well to another is investigated by pointing to the special character that underpins the noise-induced discontinuity which is caused by the generalized Brownian paths that jump beyond the barrier location without actually hitting it. This fact implies that the boundary conditions for the mean first passage time (MFPT) are no longer determined by the well-known local boundary conditions that characterize the case with normal diffusion. By numerically implementing properly the set up boundary conditions, we investigate the survival probability and the average escape time as a function of the corresponding Lévy white noise parameters. Depending on the value of the skewness β of the Lévy noise, the escape can either become enhanced or suppressed: a negative asymmetry parameter β typically yields a decrease for the escape rate while the rate itself depicts a non-monotonic behavior as a function of the stability index α that characterizes the jump length distribution of Lévy noise, exhibiting a marked discontinuity at α=1 . We find that the typical factor of 2 that characterizes for normal diffusion the ratio between the MFPT for well-bottom-to-well-bottom and well-bottom-to-barrier-top no longer holds true. For sufficiently high barriers the survival probabilities assume an exponential behavior versus time. Distinct non-exponential deviations occur, however, for low barrier heights.

  5. Life events and escape in conversion disorder.

    Science.gov (United States)

    Nicholson, T R; Aybek, S; Craig, T; Harris, T; Wojcik, W; David, A S; Kanaan, R A

    2016-09-01

    Psychological models of conversion disorder (CD) traditionally assume that psychosocial stressors are identifiable around symptom onset. In the face of limited supportive evidence such models are being challenged. Forty-three motor CD patients, 28 depression patients and 28 healthy controls were assessed using the Life Events and Difficulties Schedule in the year before symptom onset. A novel 'escape' rating for events was developed to test the Freudian theory that physical symptoms of CD could provide escape from stressors, a form of 'secondary gain'. CD patients had significantly more severe life events and 'escape' events than controls. In the month before symptom onset at least one severe event was identified in 56% of CD patients - significantly more than 21% of depression patients [odds ratio (OR) 4.63, 95% confidence interval (CI) 1.56-13.70] and healthy controls (OR 5.81, 95% CI 1.86-18.2). In the same time period 53% of CD patients had at least one 'high escape' event - again significantly higher than 14% in depression patients (OR 6.90, 95% CI 2.05-23.6) and 0% in healthy controls. Previous sexual abuse was more commonly reported in CD than controls, and in one third of female patients was contextually relevant to life events at symptom onset. The majority (88%) of life events of potential aetiological relevance were not identified by routine clinical assessments. Nine per cent of CD patients had no identifiable severe life events. Evidence was found supporting the psychological model of CD, the Freudian notion of escape and the potential aetiological relevance of childhood traumas in some patients. Uncovering stressors of potential aetiological relevance requires thorough psychosocial evaluation.

  6. Study of neutral particles

    International Nuclear Information System (INIS)

    Bartel, W.; Bulos, F.; Eisner, A.

    1975-01-01

    The range of physics problems for which a detector emphasizing neutrals is most suitable is discussed. The primary goals are the all neutrals cross section, sigma/sub o/ (e + e - → neutrals), the characterization of the neutral energy in multi-hadronic events, the search for monoenergetic photons, and good sensitivity in the difficult region of low energy photons. Those features of multi-hadronic events which are most relevant to a neutral detector were calculated using a jet model with parameters extrapolated from SPEAR energies. These distributions are presented and discussed

  7. Plasticity of Escape Responses: Prior Predator Experience Enhances Escape Performance in a Coral Reef Fish.

    Directory of Open Access Journals (Sweden)

    Ryan A Ramasamy

    Full Text Available Teleost and amphibian prey undertake fast-start escape responses during a predatory attack in an attempt to avoid being captured. Although previously viewed as a reflex reaction controlled by the autonomic nervous system, the escape responses of individuals when repeatedly startled are highly variable in their characteristics, suggesting some behavioural mediation of the response. Previous studies have shown that fishes are able to learn from past experiences, but few studies have assessed how past experience with predators affect the fast-start response. Here we determined whether prior experience with the smell or sight of a predator (the Dottyback, Pseudochromis fuscus affected the escape response of juveniles of the Spiny Chromis (Acanthochromis polyacanthus. Results show that individuals exposed to any of the predator cues prior to being startled exhibited a stronger escape response (i.e., reduced latency, increased escape distance, mean response speed, maximum response speed and maximum acceleration when compared with controls. This study demonstrates the plasticity of escape responses and highlights the potential for naïve reef fish to take into account both visual and olfactory threat cues simultaneously to optimise the amplitude of their kinematic responses to perceived risk.

  8. TWO REGIMES OF INTERACTION OF A HOT JUPITER’S ESCAPING ATMOSPHERE WITH THE STELLAR WIND AND GENERATION OF ENERGIZED ATOMIC HYDROGEN CORONA

    International Nuclear Information System (INIS)

    Shaikhislamov, I. F.; Prokopov, P. A.; Berezutsky, A. G.; Zakharov, Yu. P.; Posukh, V. G.; Khodachenko, M. L.; Lammer, H.; Kislyakova, K. G.; Fossati, L.; Johnstone, C. P.

    2016-01-01

    The interaction of escaping the upper atmosphere of a hydrogen-rich non-magnetized analog of HD 209458b with a stellar wind (SW) of its host G-type star at different orbital distances is simulated with a 2D axisymmetric multi-fluid hydrodynamic (HD) model. A realistic Sun-like spectrum of X-ray and ultraviolet radiation, which ionizes and heats the planetary atmosphere, together with hydrogen photochemistry, as well as stellar-planetary tidal interaction are taken into account to generate self-consistently an atmospheric HD outflow. Two different regimes of the planetary and SW interaction have been modeled. These are: (1) the “ captured by the star ” regime, when the tidal force and pressure gradient drive the planetary material beyond the Roche lobe toward the star, and (2) the “ blown by the wind ” regime, when sufficiently strong SW confines the escaping planetary atmosphere and channels it into the tail. The model simulates in detail the HD interaction between the planetary atoms, protons and the SW, as well as the production of energetic neutral atoms (ENAs) around the planet due to charge exchange between planetary atoms and stellar protons. The revealed location and shape of the ENA cloud, either as a paraboloid shell between the ionopause and bowshock (for the “ blown by the wind ” regime), or a turbulent layer at the contact boundary between the planetary stream and SW (for the “ captured by the star ” regime) are of importance for the interpretation of Ly α absorption features in exoplanetary transit spectra and characterization of the plasma environments.

  9. TWO REGIMES OF INTERACTION OF A HOT JUPITER’S ESCAPING ATMOSPHERE WITH THE STELLAR WIND AND GENERATION OF ENERGIZED ATOMIC HYDROGEN CORONA

    Energy Technology Data Exchange (ETDEWEB)

    Shaikhislamov, I. F.; Prokopov, P. A.; Berezutsky, A. G.; Zakharov, Yu. P.; Posukh, V. G. [Institute of Laser Physics SB RAS, Novosibirsk (Russian Federation); Khodachenko, M. L.; Lammer, H.; Kislyakova, K. G.; Fossati, L. [Space Research Institute, Austrian Acad. Sci., Graz (Austria); Johnstone, C. P., E-mail: maxim.khodachenko@oeaw.ac.at [Department of Astrophysics, University of Vienna, Vienna (Austria)

    2016-12-01

    The interaction of escaping the upper atmosphere of a hydrogen-rich non-magnetized analog of HD 209458b with a stellar wind (SW) of its host G-type star at different orbital distances is simulated with a 2D axisymmetric multi-fluid hydrodynamic (HD) model. A realistic Sun-like spectrum of X-ray and ultraviolet radiation, which ionizes and heats the planetary atmosphere, together with hydrogen photochemistry, as well as stellar-planetary tidal interaction are taken into account to generate self-consistently an atmospheric HD outflow. Two different regimes of the planetary and SW interaction have been modeled. These are: (1) the “ captured by the star ” regime, when the tidal force and pressure gradient drive the planetary material beyond the Roche lobe toward the star, and (2) the “ blown by the wind ” regime, when sufficiently strong SW confines the escaping planetary atmosphere and channels it into the tail. The model simulates in detail the HD interaction between the planetary atoms, protons and the SW, as well as the production of energetic neutral atoms (ENAs) around the planet due to charge exchange between planetary atoms and stellar protons. The revealed location and shape of the ENA cloud, either as a paraboloid shell between the ionopause and bowshock (for the “ blown by the wind ” regime), or a turbulent layer at the contact boundary between the planetary stream and SW (for the “ captured by the star ” regime) are of importance for the interpretation of Ly α absorption features in exoplanetary transit spectra and characterization of the plasma environments.

  10. Driving things

    DEFF Research Database (Denmark)

    Nevile, Maurice Richard

    2015-01-01

    . pp.155 ((http://www.infrastructure.gov.au/roads/safety/publications/2010/pdf/rsgr_2010001.pdf)) Nevile, M., Haddington, P., Heinemann, T., Rauniomaa, M. (Eds.) Interacting with objects: Language, materiality, and social activity. Amsterdam/Philadelphia: John Benjamins. Redshaw, S. (2008....... Interaction with objects reflects the car’s role beyond mere transport as a site of personal, social, and work life (Featherstone et al. 2005; Redshaw 2008). Studies of interaction examine this role as it is actually enacted, understood, and accomplished, in situ through participants’ practices (e.g. Laurier...... of in-car distractions, and how they impact driving activities (Nevile & Haddington 2010). Data are video recordings of ordinary journeys, capturing drivers and passengers in real-world real-time driving situations (27 hours, 90 journeys). For driving and road safety, research and experience has...

  11. Community Drive

    DEFF Research Database (Denmark)

    Magnussen, Rikke

    2018-01-01

    opportunity to break boundaries between research institutions and surrounding communities through the involvement of new types of actors, knowledge forms and institutions (OECD, 2011). This paper presents the project Community Drive a three year cross disciplinary community-driven game– and data-based project....... In the paper we present how the project Community Drive initiated in May 2018 is based on results from pilot projects conducted from 2014 – 2017. Overall these studies showed that it is a strong motivational factor for students to be given the task to change their living conditions through redesign...... of living in the area. The paper discusses potentials and pitfalls of designing community-driven science gaming environments and how results from previous studies can form the project Community Drive....

  12. Asymmetric Effects on Escape Rates of Bistable System

    International Nuclear Information System (INIS)

    Wang Canjun; Mei Dongcheng; Dai Zucheng

    2011-01-01

    The asymmetric effects on the escape rates from the stable states x ± in the bistable system are analyzed. The results indicate that the multiplicative noise and the additive noise always enhance the particle escape from stable states x ± of bistable. However, the asymmetric parameter r enhances the particle escape from stable state x + , and holds back the particle escape from stable state x - . (general)

  13. Measurement of the resonance escape probability

    International Nuclear Information System (INIS)

    Anthony, J.P.; Bacher, P.; Lheureux, L.; Moreau, J.; Schmitt, A.P.

    1957-01-01

    The average cadmium ratio in natural uranium rods has been measured, using equal diameter natural uranium disks. These values correlated with independent measurements of the lattice buckling, enabled us to calculate values of the resonance escape probability for the G1 reactor with one or the other of two definitions. Measurements were performed on 26 mm and 32 mm rods, giving the following values for the resonance escape probability p: 0.8976 ± 0.005 and 0.912 ± 0.006 (d. 26 mm), 0.8627 ± 0.009 and 0.884 ± 0.01 (d. 32 mm). The influence of either definition on the lattice parameters is discussed, leading to values of the effective integral. Similar experiments have been performed with thorium rods. (author) [fr

  14. Influenza A virus hemagglutinin glycosylation compensates for antibody escape fitness costs.

    Directory of Open Access Journals (Sweden)

    Ivan Kosik

    2018-01-01

    Full Text Available Rapid antigenic evolution enables the persistence of seasonal influenza A and B viruses in human populations despite widespread herd immunity. Understanding viral mechanisms that enable antigenic evolution is critical for designing durable vaccines and therapeutics. Here, we utilize the primerID method of error-correcting viral population sequencing to reveal an unexpected role for hemagglutinin (HA glycosylation in compensating for fitness defects resulting from escape from anti-HA neutralizing antibodies. Antibody-free propagation following antigenic escape rapidly selected viruses with mutations that modulated receptor binding avidity through the addition of N-linked glycans to the HA globular domain. These findings expand our understanding of the viral mechanisms that maintain fitness during antigenic evolution to include glycan addition, and highlight the immense power of high-definition virus population sequencing to reveal novel viral adaptive mechanisms.

  15. Scrunching: a novel escape gait in planarians

    Science.gov (United States)

    Cochet-Escartin, Olivier; Mickolajczyk, Keith J.; Collins, Eva-Maria S.

    2015-10-01

    The ability to escape a predator or other life-threatening situations is central to animal survival. Different species have evolved unique strategies under anatomical and environmental constraints. In this study, we describe a novel musculature-driven escape gait in planarians, ‘scrunching’, which is quantitatively different from other planarian gaits, such as gliding and peristalsis. We show that scrunching is a conserved gait among different flatworm species, underlying its importance as an escape mechanism. We further demonstrate that it can be induced by a variety of physical stimuli, including amputation, high temperature, electric shock and low pH. We discuss the functional basis for scrunching as the preferential gait when gliding is impaired due to a disruption of mucus production. Finally, we show that the key mechanical features of scrunching are adequately captured by a simple biomechanical model that is solely based on experimental data from traction force microscopy and tissue rheology without fit parameters. Together, our results form a complete description of this novel form of planarian locomotion. Because scrunching has distinct dynamics, this gait can serve as a robust behavioral readout for studies of motor neuron and muscular functions in planarians and in particular the restoration of these functions during regeneration.

  16. Escape probabilities for fluorescent x-rays

    International Nuclear Information System (INIS)

    Dance, D.R.; Day, G.J.

    1985-01-01

    Computation of the energy absorption efficiency of an x-ray photon detector involves consideration of the histories of the secondary particles produced in any initial or secondary interaction which may occur within the detector. In particular, the K or higher shell fluorescent x-rays which may be emitted following a photoelectric interaction can carry away a large fraction of the energy of the incident photon, especially if this energy is just above an absorption edge. The effects of such photons cannot be ignored and a correction term, depending upon the probability that the fluorescent x-rays will escape from the detector, must be applied to the energy absorption efficiency. For detectors such as x-ray intensifying screens, it has been usual to calculate this probability by numerical integration. In this note analytic expressions are derived for the escape probability of fluorescent photons from planar detectors in terms of exponential integral functions. Rational approximations for these functions are readily available and these analytic expressions therefore facilitate the computation of photon absorption efficiencies. A table is presented which should obviate the need for calculating the escape probability for most cases of interest. (author)

  17. Autonomous Soft Robotic Fish Capable of Escape Maneuvers Using Fluidic Elastomer Actuators.

    Science.gov (United States)

    Marchese, Andrew D; Onal, Cagdas D; Rus, Daniela

    2014-03-01

    In this work we describe an autonomous soft-bodied robot that is both self-contained and capable of rapid, continuum-body motion. We detail the design, modeling, fabrication, and control of the soft fish, focusing on enabling the robot to perform rapid escape responses. The robot employs a compliant body with embedded actuators emulating the slender anatomical form of a fish. In addition, the robot has a novel fluidic actuation system that drives body motion and has all the subsystems of a traditional robot onboard: power, actuation, processing, and control. At the core of the fish's soft body is an array of fluidic elastomer actuators. We design the fish to emulate escape responses in addition to forward swimming because such maneuvers require rapid body accelerations and continuum-body motion. These maneuvers showcase the performance capabilities of this self-contained robot. The kinematics and controllability of the robot during simulated escape response maneuvers are analyzed and compared with studies on biological fish. We show that during escape responses, the soft-bodied robot has similar input-output relationships to those observed in biological fish. The major implication of this work is that we show soft robots can be both self-contained and capable of rapid body motion.

  18. Neutralization epitopes on HIV pseudotyped with HTLV-I: conservation of carbohydrate epitopes

    DEFF Research Database (Denmark)

    Sørensen, A M; Nielsen, C; Arendrup, M

    1994-01-01

    for pseudotypes to escape neutralization by the immune system in vivo. Previous reports have suggested that carbohydrate structures may be conserved neutralization epitopes on retroviruses. In this study, the neutralizing capacity of lectins and anti-carbohydrate monoclonal antibodies was found to block infection......-negative cells, previously nonsusceptible to HIV infection. The infection of CD4-negative cells with pseudotypes could be blocked with anti-HTLV-I serum but failed to be significantly inhibited with anti-HIV serum or a V3-neutralizing anti-gp120 monoclonal antibody. This may represent a possibility...

  19. Plasma heating with multi-MeV neutral atom beams

    Energy Technology Data Exchange (ETDEWEB)

    Grisham, L.R.; Post, D.E.; Mikkelsen, D.R.; Eubank, H.P.

    1981-10-01

    We explore the utility and feasibility of neutral beams of greater than or equal to 6 AMU formed from negative ions, and also of D/sup 0/ formed from D/sup -/. The negative ions would be accelerated to approx. 1 to 2 MeV/AMU and neutralized, whereupon the neutral atoms would be used to heat and, perhaps, to drive current in magnetically confined plasmas. Such beams appear feasible and offer the promise of significant advantages relative to conventional neutral beams based on positive deuterium ions at approx. 150 keV.

  20. The cost of the sword: escape performance in male swordtails.

    Directory of Open Access Journals (Sweden)

    Alex Baumgartner

    2011-01-01

    Full Text Available The handicap theory of sexual selection posits that male display traits that are favored in mate choice come at a significant cost to performance. We tested one facet of this hypothesis in the green swordtail (Xiphophorus helleri. In this species, the lower ray of male caudal fin is extended into a 'sword', which serves to attract potential mates. However, bearing a long sword may increase drag and thus compromise a male's ability to swim effectively. We tested escape performance in this species by eliciting C-start escape responses, an instinctive escape behavior, in males with various sword lengths. We then removed males' swords and retested escape performance. We found no relationship between escape performance and sword length and no effect of sword removal on escape performance. While having a large sword may attract a predator's attention, our results suggest that sword size does not compromise a male's escape performance.

  1. Strange culinary encounters::stranger fetichism in "Jamie's Italian escape" and "Gordon's great escape"

    OpenAIRE

    Leer, Jonatan; Kjær, Katrine Meldgaard

    2015-01-01

    In this article, we examine the ways in which the encountering of 'other' food cultures is played out in the two travelogue cooking shows Gordon's Great Escape and Jamie's Italian Escape. We investigate how the two protagonist chefs Jamie Oliver and Gordon Ramsay imagine, meet and evaluate the ‘other’ food cultures in these programs, paying special attention to how the encounter with the local Indian and Italian is imagined to be a gateway to an authentic and/or primitive experience. Our main...

  2. Room escape at class: Escape games activities to facilitate the motivation and learning in computer science

    Directory of Open Access Journals (Sweden)

    Carlos Borrego

    2017-06-01

    Full Text Available Real-life room-escape games are ludic activities in which participants enter a room in order to get out of it only after solving some riddles. In this paper, we explain a Room Escape teaching experience developed in the Engineering School at Universitat Autònoma de Barcelona. The goal of this activity is to increase student’s motivation and to improve their learning on two courses of the second year in the Computer Engineering degree: Computer Networksand Information and Security.

  3. Localized Reactive Oxygen and Nitrogen Intermediates Inhibit Escape of Listeria monocytogenes from Vacuoles in Activated Macrophages1

    Science.gov (United States)

    Myers, Jesse T.; Tsang, Albert W.; Swanson, Joel A.

    2010-01-01

    Listeria monocytogenes (Lm) evades being killed after phagocytosis by macrophages by escaping from vacuoles into cytoplasm. Activated macrophages are listericidal, in part because they can retain Lm in vacuoles. This study examined the contribution of reactive oxygen intermediates (ROI) and reactive nitrogen intermediates (RNI) to the inhibition of Lm escape from vacuoles. Lm escaped from vacuoles of non-activated macrophages within 30 min of infection. Macrophages activated with IFN-γ, LPS, IL-6, and a neutralizing antibody against IL-10 retained Lm within the vacuoles, and inhibitors of ROI and RNI blocked inhibition of vacuolar escape to varying degrees. Measurements of Lm escape in macrophages from gp91phox−/− and NOS2−/− mice showed that vacuolar retention required ROI and was augmented by RNI. Live-cell imaging with the fluorogenic probe dihydro-2′,4,5,6,7,7′-hexafluorofluorescein coupled to BSA (DHFF-BSA) indicated that oxidative chemistries were generated rapidly and were localized to Lm vacuoles. Chemistries that oxidized DHFF-BSA were similar to those that retained Lm in phagosomes. Fluorescent conversion of DHFF-BSA occurred more efficiently in smaller vacuoles, indicating that higher concentrations of ROI or RNI were generated in more confining volumes. Thus, activated macrophages retained Lm within phagosomes by the combined actions of ROI and RNI in a small space. PMID:14607950

  4. Arduino adventures escape from Gemini station

    CERN Document Server

    Kelly, James Floyd

    2013-01-01

    Arduino Adventures: Escape from Gemini Station provides a fun introduction to the Arduino microcontroller by putting you (the reader) into the action of a science fiction adventure story.  You'll find yourself following along as Cade and Elle explore Gemini Station-an orbiting museum dedicated to preserving and sharing technology throughout the centuries. Trouble ensues. The station is evacuated, including Cade and Elle's class that was visiting the station on a field trip. Cade and Elle don't make it aboard their shuttle and are trapped on the station along with a friendly artificial intellig

  5. Suicide as escape from psychotic panic.

    Science.gov (United States)

    Goldblatt, Mark J; Ronningstam, Elsa; Schechter, Mark; Herbstman, Benjamin; Maltsberger, John T

    2016-01-01

    Suicides of patients in states of acute persecutory panic may be provoked by a subjective experience of helpless terror threatening imminent annihilation or dismemberment. These patients are literally scared to death and try to run away. They imagine suicide is survivable and desperately attempt to escape from imaginary enemies. These states of terror occur in a wide range of psychotic illnesses and are often associated with command hallucinations and delusions. In this article, the authors consider the subjective experience of persecutory panic and the suicide response as an attempt to flee from danger.

  6. Neutral surfaces in neutral four-spaces

    Directory of Open Access Journals (Sweden)

    Gary Jensen

    1990-11-01

    Full Text Available Properties of the Gauss map of neutral surfaces are studied. Special attention is given to surfaces of parallel, or zero, mean curvature. Bilagrangian structures are defined and used in ways analogous to the use of complex structures in the Riemannian case. The nonsimplicity of the structure group SO(2,2 is used to factor the Gauss map and to construct analogs of the twistor space, called in this context reflector space.

  7. Structural basis of hepatitis C virus neutralization by broadly neutralizing antibody HCV1

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Leopold; Giang, Erick; Robbins, Justin B.; Stanfield, Robyn L.; Burton, Dennis R.; Wilson, Ian A.; Law, Mansun (Scripps)

    2012-10-29

    Hepatitis C virus (HCV) infects more than 2% of the global population and is a leading cause of liver cirrhosis, hepatocellular carcinoma, and end-stage liver diseases. Circulating HCV is genetically diverse, and therefore a broadly effective vaccine must target conserved T- and B-cell epitopes of the virus. Human mAb HCV1 has broad neutralizing activity against HCV isolates from at least four major genotypes and protects in the chimpanzee model from primary HCV challenge. The antibody targets a conserved antigenic site (residues 412-423) on the virus E2 envelope glycoprotein. Two crystal structures of HCV1 Fab in complex with an epitope peptide at 1.8-{angstrom} resolution reveal that the epitope is a {beta}-hairpin displaying a hydrophilic face and a hydrophobic face on opposing sides of the hairpin. The antibody predominantly interacts with E2 residues Leu{sup 413} and Trp{sup 420} on the hydrophobic face of the epitope, thus providing an explanation for how HCV isolates bearing mutations at Asn{sup 415} on the same binding face escape neutralization by this antibody. The results provide structural information for a neutralizing epitope on the HCV E2 glycoprotein and should help guide rational design of HCV immunogens to elicit similar broadly neutralizing antibodies through vaccination.

  8. Molecular Dications in Planetary Atmospheric Escape

    Directory of Open Access Journals (Sweden)

    Stefano Falcinelli

    2016-08-01

    Full Text Available Fundamental properties of multiply charged molecular ions, such as energetics, structure, stability, lifetime and fragmentation dynamics, are relevant to understand and model the behavior of gaseous plasmas as well as ionosphere and astrophysical environments. Experimental determinations of the Kinetic Energy Released (KER for ions originating from dissociations reactions, induced by Coulomb explosion of doubly charged molecular ions (molecular dications produced by double photoionization of CO2, N2O and C2H2 molecules of interest in planetary atmospheres, are reported. The KER measurement as a function of the ultraviolet (UV photon energy in the range of 28–65 eV was extracted from the electron-ion-ion coincidence spectra obtained by using tunable synchrotron radiation coupled with ion imaging techniques at the ELETTRA Synchrotron Light Laboratory Trieste, Italy. These experiments, coupled with a computational analysis based on a Monte Carlo trajectory simulation, allow assessing the probability of escape for simple ionic species in the upper atmosphere of Mars, Venus and Titan. The measured KER in the case of H+, C+, CH+, CH2+, N+, O+, CO+, N2+ and NO+ fragment ions range between 1.0 and 5.5 eV, being large enough to allow these ionic species to participate in the atmospheric escape from such planets into space. In the case of Mars, we suggest a possible explanation for the observed behavior of the O+ and CO22+ ion density profiles.

  9. The escape problem for mortal walkers

    Science.gov (United States)

    Grebenkov, D. S.; Rupprecht, J.-F.

    2017-02-01

    We introduce and investigate the escape problem for random walkers that may eventually die, decay, bleach, or lose activity during their diffusion towards an escape or reactive region on the boundary of a confining domain. In the case of a first-order kinetics (i.e., exponentially distributed lifetimes), we study the effect of the associated death rate onto the survival probability, the exit probability, and the mean first passage time. We derive the upper and lower bounds and some approximations for these quantities. We reveal three asymptotic regimes of small, intermediate, and large death rates. General estimates and asymptotics are compared to several explicit solutions for simple domains and to numerical simulations. These results allow one to account for stochastic photobleaching of fluorescent tracers in bio-imaging, degradation of mRNA molecules in genetic translation mechanisms, or high mortality rates of spermatozoa in the fertilization process. Our findings provide a mathematical ground for optimizing storage containers and materials to reduce the risk of leakage of dangerous chemicals or nuclear wastes.

  10. Pavlovian Control of Escape and Avoidance.

    Science.gov (United States)

    Millner, Alexander J; Gershman, Samuel J; Nock, Matthew K; den Ouden, Hanneke E M

    2017-12-15

    To survive in complex environments, animals need to have mechanisms to select effective actions quickly, with minimal computational costs. As perhaps the computationally most parsimonious of these systems, Pavlovian control accomplishes this by hardwiring specific stereotyped responses to certain classes of stimuli. It is well documented that appetitive cues initiate a Pavlovian bias toward vigorous approach; however, Pavlovian responses to aversive stimuli are less well understood. Gaining a deeper understanding of aversive Pavlovian responses, such as active avoidance, is important given the critical role these behaviors play in several psychiatric conditions. The goal of the current study was to establish a behavioral and computational framework to examine aversive Pavlovian responses (activation vs. inhibition) depending on the proximity of an aversive state (escape vs. avoidance). We introduce a novel task in which participants are exposed to primary aversive (noise) stimuli and characterized behavior using a novel generative computational model. This model combines reinforcement learning and drift-diffusion models so as to capture effects of invigoration/inhibition in both explicit choice behavior as well as changes in RT. Choice and RT results both suggest that escape is associated with a bias for vigorous action, whereas avoidance is associated with behavioral inhibition. These results lay a foundation for future work seeking insights into typical and atypical aversive Pavlovian responses involved in psychiatric disorders, allowing us to quantify both implicit and explicit indices of vigorous choice behavior in the context of aversion.

  11. UNESCO TO BLAME: Reality or Easy Escape?

    Directory of Open Access Journals (Sweden)

    Anna Pereira Roders

    2015-03-01

    Full Text Available “UNESCO to blame” is a trend often observed in scholarly works. In those studies UNESCO is accused to privilege Eurocentric standards on heritage conservation. Is this reality or an easy escape? Can this trend be noted in other UNESCO reference texts? This article seeks to answer this question by studying the two main inscription-based conventions and their contribution to heritage management, while performing a data analysis on the countries behind these conventions, and their roles over time. The 1972 World Heritage Convention and the 2003 Convention for the Safeguarding of the Intangible Cultural Heritage are, therefore, taken as case studies. Based on the results, this paper elaborates on a critical analysis, distinguishing what UNESCO, as well as, Europe can eventually be blamed for and what may be used by the countries as an easy escape. This paper ends setting a research agenda to raise awareness and generate factual knowledge on the role of supranational governance in setting standards in global ethics, in particular, to guideline heritage conservation.

  12. Factors affecting escape distance in birds

    Directory of Open Access Journals (Sweden)

    Augusto J. Piratelli

    2015-12-01

    Full Text Available ABSTRACT The flight initiation distance has been used either to understand the cost-benefit trade-offs related to the risk of predation or as an important tool for wildlife managers. Although this variable is well-discussed for temperate regions, it is still poorly known in the Neotropics. Here we analyze the escape behavior of birds from southeastern Brazil, comparing an urban to a non-urban area. We tested for the influence of sites (urban vs. non-urban area, approaching (by one vs. two people, daytime (morning vs. afternoon, seasons (breeding vs. non-breeding and body mass on the determination of the initial (FID and final (FFD flight distances across different bird species. We predict that FID will be greater in rural areas and under a greater threat (higher number of predators approaching in the afternoon and in the non-breeding season. We also expect a direct relationship between body mass and FID and between FID and FFD. We sampled 11 species after measuring 331 escape behaviors, and we confirmed our predictions for sites (five species, daytime (one species and rejected our premise about seasons for one species. Mean FID was strongly affected by body mass, and directly affected FFD. Adjustments in FID are, most likely, an important adaptive trait in urban habitats and may partially explain the predominance of species with higher ecological plasticity in cities.

  13. Escape from viscosity : the kinematics and hydrodynamics of copepod foraging and escape swimming

    NARCIS (Netherlands)

    van Duren, LA; Videler, JJ

    Feeding and escape swimming in adult females of the calanoid copepod. Temora lopgicornis Muller were investigated and compared. Swimming velocities were calculated using a 3-D filming setup., Foraging velocities ranged between 2 and 6 min s(-1), while maximum velocities of up to 80 mm s(-1) were

  14. Strain-Specific V3 and CD4 Binding Site Autologous HIV-1 Neutralizing Antibodies Select Neutralization-Resistant Viruses.

    Science.gov (United States)

    Moody, M Anthony; Gao, Feng; Gurley, Thaddeus C; Amos, Joshua D; Kumar, Amit; Hora, Bhavna; Marshall, Dawn J; Whitesides, John F; Xia, Shi-Mao; Parks, Robert; Lloyd, Krissey E; Hwang, Kwan-Ki; Lu, Xiaozhi; Bonsignori, Mattia; Finzi, Andrés; Vandergrift, Nathan A; Alam, S Munir; Ferrari, Guido; Shen, Xiaoying; Tomaras, Georgia D; Kamanga, Gift; Cohen, Myron S; Sam, Noel E; Kapiga, Saidi; Gray, Elin S; Tumba, Nancy L; Morris, Lynn; Zolla-Pazner, Susan; Gorny, Miroslaw K; Mascola, John R; Hahn, Beatrice H; Shaw, George M; Sodroski, Joseph G; Liao, Hua-Xin; Montefiori, David C; Hraber, Peter T; Korber, Bette T; Haynes, Barton F

    2015-09-09

    The third variable (V3) loop and the CD4 binding site (CD4bs) of the HIV-1 envelope are frequently targeted by neutralizing antibodies (nAbs) in infected individuals. In chronic infection, HIV-1 escape mutants repopulate the plasma, and V3 and CD4bs nAbs emerge that can neutralize heterologous tier 1 easy-to-neutralize but not tier 2 difficult-to-neutralize HIV-1 isolates. However, neutralization sensitivity of autologous plasma viruses to this type of nAb response has not been studied. We describe the development and evolution in vivo of antibodies distinguished by their target specificity for V3 and CD4bs epitopes on autologous tier 2 viruses but not on heterologous tier 2 viruses. A surprisingly high fraction of autologous circulating viruses was sensitive to these antibodies. These findings demonstrate a role for V3 and CD4bs antibodies in constraining the native envelope trimer in vivo to a neutralization-resistant phenotype, explaining why HIV-1 transmission generally occurs by tier 2 neutralization-resistant viruses. Copyright © 2015 Elsevier Inc. All rights reserved.

  15. Crystal engineering of a zwitterionic drug to neutral cocrystals: a general solution for floxacins.

    Science.gov (United States)

    Gunnam, Anilkumar; Suresh, Kuthuru; Ganduri, Ramesh; Nangia, Ashwini

    2016-10-18

    The transformation of zwitterionic Sparfloxacin (SPX) to the neutral form is achieved by cocrystallization. Neutral forms of drugs are important for higher membrane permeability, while zwitterions are more soluble in water. The twin advantages of higher solubility/dissolution rate and good stability of neutral SPX are achieved in a molecular cocrystal compared to its zwitterionic SPX hydrate. The amine-phenol supramolecular synthon drives cocrystal formation, with the paraben ester acting as a "proton migrator" for the ionic to neutral transformation.

  16. Quantitative calculations of helium ion escape fluxes from the polar ionospheres

    International Nuclear Information System (INIS)

    Raitt, W.J.; Schunk, R.W.; Banks, P.M.

    1978-01-01

    Recent experimental measurements of He + outward fluxes have been obtained for winter and summer hemispheres. The observed fluxes indicate an average He + escape flux of 2 x 10 7 cm -2 s -1 in the winter hemisphere and a factor of 10-20 lower in the summer hemisphere. Earlier theoretical calculations had yielded winter fluxes a factor of 4 lower than the measured values and summer fluxes a further factor of 20 below the winter fluxes. We have attempted to reduce this discrepancy between our earlier theoretical model and the experimental observations by improving our theoretical model in the following ways. The helium photoionization cross sections used are accurate to 10%, the latest solar EUV fluxes measured by the Atmosphere Explorer satellites have been incorporated, and the most recent MSIS model of the neutral atmosphere is contained in the model. A range of conditions covering solar cycle, seasonal, and geomagnetic conditions were studied. The results show a maximum He + escape flux of 1.4 x 10 7 cm -2 s -1 for solar maximum, winter, low magnetic activity conditions, which is within the scatter of the measured fluxes. The computed summer He + escape flux is a factor of 20 lower than the winter value, a result which is in reasonable agreement with the summer experimental observations. Possible reasons for the slight discrepancy between theory and experiment in summer are discussed

  17. Achieving Airport Carbon Neutrality

    Science.gov (United States)

    2016-03-01

    This report is a guide for airports that wish to reduce or eliminate greenhouse gas (GHG) emissions from existing buildings and operations. Reaching carbon neutrality typically requires the use of multiple mechanisms to first minimize energy consumpt...

  18. A high energy neutral beam system for reactors

    International Nuclear Information System (INIS)

    Anderson, O.A.; Chan, C.F.; Cooper, W.S.

    1988-09-01

    High energy neutral beams provide a promising method of heating and driving current in steady-state tokamak fusion reactors. As an example, we have made a conceptual design of a neutral beam system for current drive on the International Thermonuclear Experimental Reactor (ITER). The system, based on electrostatic acceleration of D/sup /minus// ions, can deliver up to 100 MW of 1.6 MeV D 0 neutrals through three ports. Radiation protection is provided by locating sensitive beamline components 35 to 50 m from the reactor. In an application to a 3300 MW power reactor, a system delivering 120 MW of 2-2.4 MeV deuterium beams assisted by 21 MW of lower hybrid wave power drives 25 MA and provides an adequate plasma power gain (Q = 24) for a commercial fusion power plant. 8 refs., 1 fig., 2 tabs

  19. Some Possible Cases of Escape Mimicry in Neotropical Butterflies.

    Science.gov (United States)

    Pinheiro, C E G; Freitas, A V L

    2014-10-01

    The possibility that escape or evasive mimicry evolved in butterflies and other prey insects in a similar fashion to classical Batesian and Müllerian mimicry has long been advanced in the literature. However, there is a general disagreement among lepidopterists and evolutionary biologists on whether or not escape mimicry exists, as well as in which mimicry rings this form of mimicry has evolved. Here, we review some purported cases of escape mimicry in Neotropical butterflies and suggest new mimicry rings involving several species of Archaeoprepona, Prepona, and Doxocopa (the "bright blue bands" ring) and species of Colobura and Hypna (the "creamy bands" ring) where the palatability of butterflies, their ability to escape predator attacks, geographic distribution, relative abundance, and co-occurrence in the same habitats strongly suggest that escape mimicry is involved. In addition, we also indicate other butterfly taxa whose similarities of coloration patterns could be due to escape mimicry and would constitute important case studies for future investigation.

  20. Effect of Orbital Distance on the Atmospheric Escape of Exoplanets

    Science.gov (United States)

    Mo, Yang; Jian-heng, Guo

    2018-01-01

    Atmospheric escape is an important sector in the evolution of planetary atmosphere, and its energy is mainly originated from the radiation of the host star at the high energy band. The radiation flux drops dramatically with the increase of orbital distance, there is a large difference of planetary atmospheric escape in different orbits, so it is necessary to study the impact of orbital distance on the atmospheric escape of an exoplanet. We consider the radiation transfer and the photochemical reactions of multiple kinds of particles to study the variation of planetary atmospheric escape with the orbital distance by using a 1-D hydrodynamic model. Due to the large differences of the spectra of host stars in different evolution stages, the Astrophysical Plasma Emission Code (APEC) in the X-Ray Spectral Fitting Package (XSPEC) is used to obtain the spectra of solar-type stars with different ages as the input spectra of the model. The results indicate that the escape rates of the exoplanets in different orbits are different significantly, and the escape mechanism is converted from the drastic hydrodynamic escape into the moderate Jeans escape as the orbital distance increases, the smaller the planetary gravitational potential, the younger the star-planet system, the larger the distance of this conversion. The correlation between the escape rate and the radiation flux decreases for the short-period exoplanets in a younger star-planet system. It is shown that the classical energy-limited escape theory is not suitable for this kind of exoplanets. These results have enriched the studies on the atmospheric escape of exoplanets, especially, extended the studies on the escape mechanism and energy conversion under different orbital distances and stellar ages.

  1. Escape response of planktonic protists to fluid mechanical signals

    DEFF Research Database (Denmark)

    Jakobsen, Hans Henrik

    2001-01-01

    The escape response to fluid mechanical signals was examined in 6 protists, 4 ciliates and 2 dinoflagellates. When exposed to a siphon flow. 3 species of ciliates, Balanion comatum, Strobilidium sp., and Mesodinium pulex, responded with escape jumps. The threshold deformation rates required...... to elicit an escape ranged between 1.8 and 3 s(-1). Escape speeds varied between 100 to 150 body length s(-1). Jump directions were non- random in all jumping species and had a negative geotactic component. In a grazing experiment with copepods, the predation mortality of a jumping ciliate was about 15...

  2. Immunogenetic mechanisms driving norovirus GII.4 antigenic variation.

    Directory of Open Access Journals (Sweden)

    Lisa C Lindesmith

    Full Text Available Noroviruses are the principal cause of epidemic gastroenteritis worldwide with GII.4 strains accounting for 80% of infections. The major capsid protein of GII.4 strains is evolving rapidly, resulting in new epidemic strains with altered antigenic potentials. To test if antigenic drift may contribute to GII.4 persistence, human memory B cells were immortalized and the resulting human monoclonal antibodies (mAbs characterized for reactivity to a panel of time-ordered GII.4 virus-like particles (VLPs. Reflecting the complex exposure history of the volunteer, human anti-GII.4 mAbs grouped into three VLP reactivity patterns; ancestral (1987-1997, contemporary (2004-2009, and broad (1987-2009. NVB 114 reacted exclusively to the earliest GII.4 VLPs by EIA and blockade. NVB 97 specifically bound and blocked only contemporary GII.4 VLPs, while NBV 111 and 43.9 exclusively reacted with and blocked variants of the GII.4.2006 Minerva strain. Three mAbs had broad GII.4 reactivity. Two, NVB 37.10 and 61.3, also detected other genogroup II VLPs by EIA but did not block any VLP interactions with carbohydrate ligands. NVB 71.4 cross-neutralized the panel of time-ordered GII.4 VLPs, as measured by VLP-carbohydrate blockade assays. Using mutant VLPs designed to alter predicted antigenic epitopes, two evolving, GII.4-specific, blockade epitopes were mapped. Amino acids 294-298 and 368-372 were required for binding NVB 114, 111 and 43.9 mAbs. Amino acids 393-395 were essential for binding NVB 97, supporting earlier correlations between antibody blockade escape and carbohydrate binding variation. These data inform VLP vaccine design, provide a strategy for expanding the cross-blockade potential of chimeric VLP vaccines, and identify an antibody with broadly neutralizing therapeutic potential for the treatment of human disease. Moreover, these data support the hypothesis that GII.4 norovirus evolution is heavily influenced by antigenic variation of neutralizing

  3. Escape of Black Holes from the Brane

    International Nuclear Information System (INIS)

    Flachi, Antonino; Tanaka, Takahiro

    2005-01-01

    TeV-scale gravity theories allow the possibility of producing small black holes at energies that soon will be explored at the CERN LHC or at the Auger observatory. One of the expected signatures is the detection of Hawking radiation that might eventually terminate if the black hole, once perturbed, leaves the brane. Here, we study how the 'black hole plus brane' system evolves once the black hole is given an initial velocity that mimics, for instance, the recoil due to the emission of a graviton. The results of our dynamical analysis show that the brane bends around the black hole, suggesting that the black hole eventually escapes into the extra dimensions once two portions of the brane come in contact and reconnect. This gives a dynamical mechanism for the creation of baby branes

  4. The fastest saccadic responses escape visual masking

    DEFF Research Database (Denmark)

    Crouzet, Sébastien M.; Overgaard, Morten; Busch, Niko A.

    2014-01-01

    visual processing while the initial feedforward processing is thought to be left intact. We tested a prediction derived from this hypothesis: the fastest responses, being triggered before the beginning of reentrant processing, should escape the OSM interference. In a saccadic choice reaction time task......, which gives access to very early stages of visual processing, target visibility was reduced either by OSM, conventional backward masking, or low stimulus contrast. A general reduction of performance was observed in all three conditions. However, the fastest saccades did not show any sign of interference...... under either OSM or backward masking, as they did under the low-contrast condition. This finding supports the hypothesis that masking interferes mostly with reentrant processing at later stages, while leaving early feedforward processing largely intact....

  5. Escape Burrowing of Modern Freshwater Bivalves as a Paradigm for Escape Behavior in the Devonian Bivalve Archanodon catskillensis

    Directory of Open Access Journals (Sweden)

    Katja Knoll

    2017-10-01

    Full Text Available Many freshwater bivalves restore themselves to the sediment water interface after burial by upward escape burrowing. We studied the escape burrowing capacity of two modern unionoids, Elliptio complanata and Pyganodon cataracta and the invasive freshwater venerid Corbicula fluminea, in a controlled laboratory setting varying sediment grain size and burial depth. We found that the relatively streamlined E. complanata is a better escape burrower than the more obese P. cataracta. E. complanata is more likely to escape burial in both fine and coarse sand, and at faster rates than P. cataracta. However, successful escape from 10 cm burial, especially in fine sand, is unlikely for both unionoids. The comparatively small and obese C. fluminea outperforms both unionoids in terms of escape probability and escape time, especially when body size is taken into consideration. C. fluminea can escape burial depths many times its own size, while the two unionoids rarely escape from burial equivalent to the length of their shells. E. complanata, and particularly P. cataracta, are morphological paradigms for the extinct Devonian unionoid bivalve Archanodon catskillensis, common in riverine facies of the Devonian Catskill Delta Complex of the eastern United States. Our observations suggest that the escape burrowing capability of A. catskillensis was no better than that of P. cataracta. Archanodon catskillensis was likely unable to escape burial of more than a few centimeters of anastrophically deposited sediment. The long (up to 1 meter, vertical burrows that are associated with A. catskillensis, and interpreted to be its escape burrows, represent a response to episodic, small-scale sedimentation events due to patterns of repetitive hydrologic or weather-related phenomena. They are not a response to a single anastrophic event involving the influx of massive volumes of sediment.

  6. Neutralizing Antibodies and Pathogenesis of Hepatitis C Virus Infection

    Directory of Open Access Journals (Sweden)

    Françoise Stoll-Keller

    2012-10-01

    Full Text Available Hepatitis C virus (HCV infection is a major cause of chronic liver disease worldwide. The interplay between the virus and host innate and adaptive immune responses determines the outcome of infection. There is increasing evidence that host neutralizing responses play a relevant role in the resulting pathogenesis. Furthermore, viral evasion from host neutralizing antibodies has been revealed to be an important contributor in leading both to viral persistence in acute liver graft infection following liver transplantation, and to chronic viral infection. The development of novel model systems to study HCV entry and neutralization has allowed a detailed understanding of the molecular mechanisms of virus-host interactions during antibody-mediated neutralization. The understanding of these mechanisms will ultimately contribute to the development of novel antiviral preventive strategies for liver graft infection and an urgently needed vaccine. This review summarizes recent concepts of the role of neutralizing antibodies in viral clearance and protection, and highlights consequences of viral escape from neutralizing antibodies in the pathogenesis of HCV infection.

  7. Escaping 1 MeV tritons in TFTR

    International Nuclear Information System (INIS)

    Zweben, S.J.; Strachan, J.D.; Boivin, R.; Cavallo, A.; Fredrickson, E.D.; McGuire, K.; Mynick, H.E.; White, R.B.

    1989-01-01

    1 MeV tritons created by D-D reactions can simulate the 'single-particle' behavior expected with 3.5 MeV D-T alphas, since the gyroradii and slowing-down of these two particles are similar. This paper describes measurements of the flux of escaping 1 MeV tritons from the TFTR plasma during high power D 0 →D neutral beam injection, and shows that in most cases the observed triton loss is consistent with the classical (single-particle) first-orbit loss model. In this model tritons are lost if their first orbit intersects the wall due to their large banana width, while almost all tritons confined on their first orbit should stay confined until thermalized. The triton detectors are ZnS(Ag) scintillator screens housed in light-tight boxes located just outside the plasma boundary at the bottom of the TFTR vessel. They are particle 'pinhole' cameras which can resolve the triton flux vs. pitch angle (to ±5 o ), energy (to ±50 %), and time (to <20 μsec). The 2-D images of triton flux onto these scintillators are optically coupled to either an intensified TV camera or to photomultiplyer tubes for fast time resolution. The soft x-ray background in an earlier prototype has been eliminated. Although there are presently 8 such detectors in TFTR, this paper discusses results from only the detector located just below the vessel center (R=259 cm, r=102 cm). Note that the '1 MeV triton' signal discussed below also has about a 30 % contribution from 3 MeV protons; however, since these two particles have identical gyroradii they should behave alike. 5 refs., 5 figs

  8. Managing Pacific salmon escapements: The gaps between theory and reality

    Science.gov (United States)

    Knudsen, E. Eric; Knudsen, E. Eric; Steward, Cleveland R.; MacDonald, Donald D.; Williams, Jack E.; Reiser, Dudley W.

    1999-01-01

    There are myriad challenges to estimating intrinsic production capacity for Pacific salmon populations that are heavily exploited and/or suffering from habitat alteration. Likewise, it is difficult to determine whether perceived decreases in production are due to harvest, habitat, or hatchery influences, natural variation, or some combination of all four. There are dramatic gaps between the true nature of the salmon spawner/recruit relationship and the theoretical basis for describing and understanding the relationship. Importantly, there are also extensive practical difficulties associated with gathering and interpreting accurate escapement and run-size information and applying it to population management. Paradoxically, certain aspects of salmon management may well be contributing to losses in abundance and biodiversity, including harvesting salmon in mixed population fisheries, grouping populations into management units subject to a common harvest rate, and fully exploiting all available hatchery fish at the expense of wild fish escapements. Information on U.S. Pacific salmon escapement goal-setting methods, escapement data collection methods and estimation types, and the degree to which stocks are subjected to mixed stock fisheries was summarized and categorized for 1,025 known management units consisting of 9,430 known populations. Using criteria developed in this study, only 1% of U.S. escapement goals are by methods rated as excellent. Escapement goals for 16% of management units were rated as good. Over 60% of escapement goals have been set by methods rated as either fair or poor and 22% of management units have no escapement goals at all. Of the 9,430 populations for which any information was available, 6,614 (70%) had sufficient information to categorize the method by which escapement data are collected. Of those, data collection methods were rated as excellent for 1%, good for 1%, fair for 2%, and poor for 52%. Escapement estimates are not made for 44

  9. Lower hybrid current drive in shaped tokamaks

    International Nuclear Information System (INIS)

    Kesner, J.

    1993-01-01

    A time dependent lower hybrid current drive tokamak simulation code has been developed. This code combines the BALDUR tokamak simulation code and the Bonoli/Englade lower hybrid current drive code and permits the study of the interaction of lower hybrid current drive with neutral beam heating in shaped cross-section plasmas. The code is time dependent and includes the beam driven and bootstrap currents in addition to the current driven by the lower hybrid system. Examples of simulations are shown for the PBX-M experiment which include the effect of cross section shaping on current drive, ballooning mode stabilization by current profile control and sawtooth stabilization. A critical question in current drive calculations is the radial transport of the energetic electrons. The authors have developed a response function technique to calculate radial transport in the presence of an electric field. The consequences of the combined influences of radial diffusion and electric field acceleration are discussed

  10. Neutral Beam Development for the Lockheed Martin Compact Fusion Reactor

    Science.gov (United States)

    Ebersohn, Frans; Sullivan, Regina

    2017-10-01

    The Compact Fusion Reactor project at Lockheed Martin Skunk Works is developing a neutral beam injection system for plasma heating. The neutral beam plasma source consists of a high current lanthanum hexaboride (LaB6) hollow cathode which drives an azimuthal cusp discharge similar to gridded ion thrusters. The beam is extracted with a set of focusing grids and is then neutralized in a chamber pumped with Titanium gettering. The design, testing, and analyses of individual components are presented along with the most current full system results. The goal of this project is to advance in-house neutral beam expertise at Lockheed Martin to aid in operation, procurement, and development of neutral beam technology. ©2017 Lockheed Martin Corporation. All Rights Reserved.

  11. Buying to blunt negative feelings : Materialistic escape from the self

    NARCIS (Netherlands)

    Donnelly, Grant E.; Ksendzova, Masha; Howell, Ryan T.; Vohs, Kathleen D.; Baumeister, Roy F.

    2016-01-01

    We propose that escape theory, which describes how individuals seek to free themselves from aversive states of self-awareness, helps explain key patterns of materialistic people's behavior. As predicted by escape theory, materialistic individuals may feel dissatisfied with their standard of living,

  12. Escape of protists in predator-generated feeding currents

    DEFF Research Database (Denmark)

    Jakobsen, Hans Henrik

    2002-01-01

    The ciliate Strobilidium sp. and 2 flagellates, Chrysochromulina simplex and Gymnodinium sp., were exposed to predator-generated feeding currents, and their escape responses were quantified using 2- and 3-dimensional video techniques. All 3 studied organisms responded by escaping at a defined...

  13. 30 CFR 75.382 - Mechanical escape facilities.

    Science.gov (United States)

    2010-07-01

    ... with brakes that can stop the fully loaded platform, cage, or other device. (c) Mechanical escape facilities, including automatic elevators, shall be examined weekly. The weekly examination of this equipment... cages, platforms, or elevators. (e) Mechanical escape facilities shall have rated capacities consistent...

  14. Theoretical studies of non inductive current drive in compact toroids

    NARCIS (Netherlands)

    Farengo, R; Lifschitz, AF; Caputi, KI; Arista, NR; Clemente, RA

    Three non inductive current drive methods that can be applied to compact toroids axe studied. The use of neutral beams to drive current in field reversed configurations and spheromaks is studied using a Monte Carlo code that includes a complete ionization package and follows the exact particle

  15. The importance of timing for breaking commuters’ car driving habits

    DEFF Research Database (Denmark)

    Thøgersen, John

    2012-01-01

    A large sample of Copenhagen car drivers were randomly assigned to either receive a free month travel card for public transportation or serve as a control group. As predicted, the free travel card neutralized the negative effect of car driving habits and made the use of public transportation more...... alternatives to car-driving....

  16. Escape rate scaling in infinite measure preserving systems

    International Nuclear Information System (INIS)

    Munday, Sara; Knight, Georgie

    2016-01-01

    We investigate the scaling of the escape rate from piecewise linear dynamical systems displaying intermittency due to the presence of an indifferent fixed point. Strong intermittent behaviour in the dynamics can result in the system preserving an infinite measure. We define a neighbourhood of the indifferent fixed point to be a hole through which points escape and investigate the scaling of the rate of this escape as the length of the hole decreases, both in the finite measure preserving case and infinite measure preserving case. In the infinite measure preserving systems we observe logarithmic corrections to and polynomial scaling of the escape rate with hole length. Finally we conjecture a relationship between the wandering rate and the observed scaling of the escape rate. (paper)

  17. Entrapment and escape of liquid lubricant in metal forming

    DEFF Research Database (Denmark)

    Bech, Jakob Ilsted; Bay, Niels; Eriksen, Morten

    1999-01-01

    Using a transparent tool entrapment, compression and eventual escape of liquid lubricant in surface pockets is observed in plane strip drawing. The two mechanisms of lubricant escape. Micro Plasto HydroDynamic and Hydrostatic Lubrication (MPHDL and MPHSL), are observed and quantified experimentally...... with Varying viscosity, speed, reduction, workpiece material, back tension and friction. The mechanisms are influenced by all these parameters in an explicable way. Theoretical models of the escape mechanisms are established combining continuum mechanic analyses of the die pressure distribution with a fluid...... mechanic analysis of the lubricant escape. Oscillations in the drawing force are caused by the local escape of lubricant. (C) 1999 Elsevier Science S.A. All rights reserved....

  18. Measurements of Lyman-Alpha Escape From HST Far-UV Spectral SNAP Survey of 33 Starforming Galaxies: Initial Results

    Science.gov (United States)

    Redwine, Keith

    2018-01-01

    This thesis will describe and analyze far-UV spectra from nearby starforming galaxies to investigate how line features like the hydrogen Lyman-alpha (Lyα) line at 1216 Å are related to the local properties of the host galaxy. It has been suggested that Lyα can be used as a proxy for the escape of Lyman continuum (LyC) radiation, the escape of of which from bright regions of galaxies is of particular interest. Most notably, the reionization epoch of neutral atomic hydrogen in the universe over a redshift range from z∼6 to z∼12, was highly dependent on the flux of ionizing LyC photons in the interstellar and intergalactic media. Expanding our understanding of the dynamics of the Lyα escape fraction (fLyα) from the local environment of its emission could be key to determining a total LyC escape fraction (fLyC) across all morphologies of galaxies. The wide range of Lyα emitters and absorbors (occasionally both) of this Cycle 22 SNAP survey observed by the Cosmic Origins Spectrograph (COS) onboard Hubble Space Telescope (HST) provides a unique look at far-UV spectra in candidate LyC emitters. Lyα profiles are easily observable in short exposures, and line features discernable in the low-resolution G140L mode can inform and guide future observations by COS or other FUV spectroscopy.

  19. CO2-Neutral Fuels

    NARCIS (Netherlands)

    Goede, A.; van de Sanden, M. C. M.

    2016-01-01

    Mimicking the biogeochemical cycle of System Earth, synthetic hydrocarbon fuels are produced from recycled CO2 and H2O powered by renewable energy. Recapturing CO2 after use closes the carbon cycle, rendering the fuel cycle CO2 neutral. Non-equilibrium molecular CO2 vibrations are key to high energy

  20. Issues in neutral currents

    International Nuclear Information System (INIS)

    Sehgal, L.M.

    1980-01-01

    The experimental results on low energy confirming the structure of the effective Lagrangian of the weak neutral current processes as predicted by the Salam-Weinberg model are reviewed. Some possible modifications of the effective Lagrangian and the feasibility of their experimental verification are also considered. (P.L.)

  1. Escape route simulator utilizing augmented reality

    Energy Technology Data Exchange (ETDEWEB)

    Mattos, Karen Salazar Ribeiro de; Mó, Antônio Carlos de A.; Santo, André Cotelli do E.; Silva, Marcio Henrique, E-mail: karensalazar.1190@gmail.com [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Centro Universitário Carioca (UniCarioca), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    Due to increasing demand and interest in the interaction of technology platforms and integration of different types of systems and technologies, some tools are already providing practical ways to develop integrated applications. The tools explored by this article are Unity, a platform for game development, and Vuforia, an SDK, software development kit, for augmented reality creation. The coalition proposal of these resources is to create an intuitive escape route that can be used for the evacuation of buildings or open spaces in view of imminent danger, such as radiation leakage, and that can be accessed from a target available at the institution. It has also the intention of simulating situations that involve training of personnel in order to obtain methods that allow to save financial resources, and even to avoid that those who are involved are exposed to risks unnecessarily. The simulator is expected to help design, test, and improve ways to maintain the physical integrity of the facility and provide end users with a better sense of immersion and attractiveness. (author)

  2. Immune escape strategies of malaria parasites

    Directory of Open Access Journals (Sweden)

    Pollyanna Stephanie Gomes

    2016-10-01

    Full Text Available Malaria is one of the most life-threatening infectious diseases worldwide. Immunity to malaria is slow and short-lived despite the repeated parasite exposure in endemic areas. Malaria parasites have evolved refined machinery to evade the immune system based on a range of genetic changes that include allelic variation, biomolecular exposure of proteins and intracellular replication. All of these features increase the probability of survival in both mosquitoes and the vertebrate host. Plasmodium species escape from the first immunological trap in its invertebrate vector host, the Anopheles mosquitoes. The parasites have to pass through various immunological barriers within the mosquito such as anti-microbial molecules and the mosquito microbiota in order to achieve successful transmission to the vertebrate host. Within these hosts, Plasmodium species employ various immune evasion strategies during different life cycle stages. Parasite persistence against the vertebrate immune response depends on the balance among virulence factors, pathology, metabolic cost of the host immune response, and the parasites ability to evade the immune response. In this review we discuss the strategies that Plasmodium parasites use to avoid the vertebrate host immune system and how they promote successful infection and transmission.

  3. Escaping the resource curse in China.

    Science.gov (United States)

    Cao, Shixiong; Li, Shurong; Ma, Hua; Sun, Yutong

    2015-02-01

    Many societies face an income gap between rich regions with access to advanced technology and regions that are rich in natural resources but poorer in technology. This "resource curse" can lead to a Kuznets trap, in which economic inequalities between the rich and the poor increase during the process of socioeconomic development. This can also lead to depletion of natural resources, environmental degradation, social instability, and declining socioeconomic development. These problems will jeopardize China's achievements if the current path continues to be pursued without intervention by the government to solve the problems. To mitigate the socioeconomic development gap between western and eastern China, the government implemented its Western Development Program in 2000. However, recent data suggest that this program has instead worsened the resource curse. Because each region has its own unique strengths and weaknesses, China must escape the resource curse by accounting for this difference; in western China, this can be done by improving education, promoting high-tech industry, adjusting its economic strategy to balance regional development, and seeking more sustainable approaches to socioeconomic development.

  4. Escape route simulator utilizing augmented reality

    International Nuclear Information System (INIS)

    Mattos, Karen Salazar Ribeiro de; Mó, Antônio Carlos de A.; Santo, André Cotelli do E.; Silva, Marcio Henrique

    2017-01-01

    Due to increasing demand and interest in the interaction of technology platforms and integration of different types of systems and technologies, some tools are already providing practical ways to develop integrated applications. The tools explored by this article are Unity, a platform for game development, and Vuforia, an SDK, software development kit, for augmented reality creation. The coalition proposal of these resources is to create an intuitive escape route that can be used for the evacuation of buildings or open spaces in view of imminent danger, such as radiation leakage, and that can be accessed from a target available at the institution. It has also the intention of simulating situations that involve training of personnel in order to obtain methods that allow to save financial resources, and even to avoid that those who are involved are exposed to risks unnecessarily. The simulator is expected to help design, test, and improve ways to maintain the physical integrity of the facility and provide end users with a better sense of immersion and attractiveness. (author)

  5. Neutral particle dynamics in the Alcator C-Mod tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Niemczewski, Artur P. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

    1995-08-01

    This thesis presents an experimental study of neutral particle dynamics in the Alcator C-Mod tokamak. The primary diagnostic used is a set of six neutral pressure gauges, including special-purpose gauges built for in situ tokamak operation. While a low main chamber neutral pressure coincides with high plasma confinement regimes, high divertor pressure is required for heat and particle flux dispersion in future devices such as ITER. Thus we examine conditions that optimize divertor compression, defined here as a divertor-to-midplane pressure ratio. We find both pressures depend primarily on the edge plasma regimes defined by the scrape-off-layer heat transport. While the maximum divertor pressure is achieved at high core plasma densities corresponding to the detached divertor state, the maximum compression is achieved in the high-recycling regime. Variations in the divertor geometry have a weaker effect on the neutral pressures. For otherwise similar plasmas the divertor pressure and compression are maximum when the strike point is at the bottom of the vertical target plate. We introduce a simple flux balance model, which allows us to explain the divertor neutral pressure across a wide range of plasma densities. In particular, high pressure sustained in the detached divertor (despite a considerable drop in the recycling source) can be explained by scattering of neutrals off the cold plasma plugging the divertor throat. Because neutrals are confined in the divertor through scattering and ionization processes (provided the mean-free-paths are much shorter than a typical escape distance) tight mechanical baffling is unnecessary. The analysis suggests that two simple structural modifications may increase the divertor compression in Alcator C-Mod by a factor of about 5. Widening the divertor throat would increase the divertor recycling source, while closing leaks in the divertor structure would eliminate a significant neutral loss mechanism.

  6. Modelling the evolution and spread of HIV immune escape mutants.

    Directory of Open Access Journals (Sweden)

    Helen R Fryer

    2010-11-01

    Full Text Available During infection with human immunodeficiency virus (HIV, immune pressure from cytotoxic T-lymphocytes (CTLs selects for viral mutants that confer escape from CTL recognition. These escape variants can be transmitted between individuals where, depending upon their cost to viral fitness and the CTL responses made by the recipient, they may revert. The rates of within-host evolution and their concordant impact upon the rate of spread of escape mutants at the population level are uncertain. Here we present a mathematical model of within-host evolution of escape mutants, transmission of these variants between hosts and subsequent reversion in new hosts. The model is an extension of the well-known SI model of disease transmission and includes three further parameters that describe host immunogenetic heterogeneity and rates of within host viral evolution. We use the model to explain why some escape mutants appear to have stable prevalence whilst others are spreading through the population. Further, we use it to compare diverse datasets on CTL escape, highlighting where different sources agree or disagree on within-host evolutionary rates. The several dozen CTL epitopes we survey from HIV-1 gag, RT and nef reveal a relatively sedate rate of evolution with average rates of escape measured in years and reversion in decades. For many epitopes in HIV, occasional rapid within-host evolution is not reflected in fast evolution at the population level.

  7. Structure of Rotavirus Outer-Layer Protein VP7 Bound with a Neutralizing Fab

    Energy Technology Data Exchange (ETDEWEB)

    Aoki, Scott T.; Settembre, Ethan C.; Trask, Shane D.; Greenberg, Harry B.; Harrison, Stephen C.; Dormitzer, Philip R.; (Stanford-MED); (CH-Boston)

    2009-06-17

    Rotavirus outer-layer protein VP7 is a principal target of protective antibodies. Removal of free calcium ions (Ca{sup 2+}) dissociates VP7 trimers into monomers, releasing VP7 from the virion, and initiates penetration-inducing conformational changes in the other outer-layer protein, VP4. We report the crystal structure at 3.4 angstrom resolution of VP7 bound with the Fab fragment of a neutralizing monoclonal antibody. The Fab binds across the outer surface of the intersubunit contact, which contains two Ca{sup 2+} sites. Mutations that escape neutralization by other antibodies suggest that the same region bears the epitopes of most neutralizing antibodies. The monovalent Fab is sufficient to neutralize infectivity. We propose that neutralizing antibodies against VP7 act by stabilizing the trimer, thereby inhibiting the uncoating trigger for VP4 rearrangement. A disulfide-linked trimer is a potential subunit immunogen.

  8. Safe driving for teens

    Science.gov (United States)

    Driving and teenagers; Teens and safe driving; Automobile safety - teenage drivers ... MAKE A COMMITTMENT TO SAFETY Teens also need to commit to being safe and responsible drivers in order to improve the odds in their favor. Reckless driving ...

  9. Escape to infinity under the action of a potential and a constant electromagnetic field

    CERN Document Server

    Gascon, F G

    2003-01-01

    Escape to infinity is proved for a great variety of potentials, including the potential created by an infinite number of sources. Relativistic escape is studied. Escape in the presence of a constant electromagnetic field and a potential is also considered.

  10. Neutral atom traps.

    Energy Technology Data Exchange (ETDEWEB)

    Pack, Michael Vern

    2008-12-01

    This report describes progress in designing a neutral atom trap capable of trapping sub millikelvin atom in a magnetic trap and shuttling the atoms across the atom chip from a collection area to an optical cavity. The numerical simulation and atom chip design are discussed. Also, discussed are preliminary calculations of quantum noise sources in Kerr nonlinear optics measurements based on electromagnetically induced transparency. These types of measurements may be important for quantum nondemolition measurements at the few photon limit.

  11. Ion-Ion Neutralization.

    Science.gov (United States)

    1982-05-31

    of Birmingam, P 0 Box 363, 2310/A2 Birmingham B15 2TT, England. 2303/GlAC II. Controlling Office Name and Address 12. Report Date Air Force Geophysics...source. Thus unwanted molecular excitation and dissociation can be avoided and greater control can be exercised in the creation of suitable plasma...The Fall fractigRal ionization density in these afterglow plagas (%-10 -𔃺) ensures that electron- neutral collisions are the most effective. This

  12. Exercise Equipment: Neutral Buoyancy

    Science.gov (United States)

    Shackelford, Linda; Valle, Paul

    2016-01-01

    Load Bearing Equipment for Neutral Buoyancy (LBE-NB) is an exercise frame that holds two exercising subjects in position as they apply counter forces to each other for lower extremity and spine loading resistance exercises. Resistance exercise prevents bone loss on ISS, but the ISS equipment is too massive for use in exploration craft. Integrating the human into the load directing, load generating, and motion control functions of the exercise equipment generates safe exercise loads with less equipment mass and volume.

  13. Gargamelle: neutral current event

    CERN Multimedia

    1973-01-01

    This event shows real tracks of particles from the 1200 litre Gargamelle bubble chamber that ran on the PS from 1970 to 1976 and on the SPS from 1976 to 1979. In this image a neutrino passes close to a nucleon and reemerges as a neutrino. Such events are called neutral curent, as they are mediated by the Z0 boson which has no electric charge.

  14. Antihypertensive neutral lipid

    Science.gov (United States)

    Snyder, F.L.; Blank, M.L.

    1984-10-26

    The invention relates to the discovery of a class of neutral acetylated either-linked glycerolipids having the capacity to lower blood presure in warm-blooded animals. This physiological effect is structure sensitive requiring a long chain alkyl group at the sn-1 position and a short carbon chain acyl group (acetyl or propionyl) at the sn-2 position, and a hydroxyl group at the sn-3 position.

  15. Neutral particle beam intensity controller

    Science.gov (United States)

    Dagenhart, W.K.

    1984-05-29

    The neutral beam intensity controller is based on selected magnetic defocusing of the ion beam prior to neutralization. The defocused portion of the beam is dumped onto a beam dump disposed perpendicular to the beam axis. Selective defocusing is accomplished by means of a magnetic field generator disposed about the neutralizer so that the field is transverse to the beam axis. The magnetic field intensity is varied to provide the selected partial beam defocusing of the ions prior to neutralization. The desired focused neutral beam portion passes along the beam path through a defining aperture in the beam dump, thereby controlling the desired fraction of neutral particles transmitted to a utilization device without altering the kinetic energy level of the desired neutral particle fraction. By proper selection of the magnetic field intensity, virtually zero through 100% intensity control of the neutral beam is achieved.

  16. Neutral ISM, Ly α , and Lyman-continuum in the Nearby Starburst Haro 11

    Energy Technology Data Exchange (ETDEWEB)

    Rivera-Thorsen, T. Emil; Östlin, Göran; Hayes, Matthew; Puschnig, Johannes, E-mail: trive@astro.su.se [Department of Astronomy, Stockholm University, AlbaNova University Centre, SE-106 91 Stockholm (Sweden)

    2017-03-01

    Star-forming galaxies are believed to be a major source of Lyman continuum (LyC) radiation responsible for reionizing the early universe. Direct observations of escaping ionizing radiation have however been sparse and with low escape fractions. In the local universe, only 10 emitters have been observed, with typical escape fractions of a few percent. The mechanisms regulating this escape need to be strongly evolving with redshift in order to account for the epoch of reionization. Gas content and star formation feedback are among the main suspects, known to both regulate neutral gas coverage and evolve with cosmic time. In this paper, we reanalyze Hubble Space Telescope ( HST )-Cosmic Origins Spectrograph (COS) spectrocopy of the first detected local LyC leaker, Haro 11. We examine the connection between LyC leakage and Ly α line shape, and feedback-influenced neutral interstellar medium (ISM) properties like kinematics and gas distribution. We discuss the two extremes of an optically thin, density bounded ISM and a riddled, optically thick, ionization bounded ISM, and how Haro 11 fits into theoretical predictions. We find that the most likely ISM model is a clumpy neutral medium embedded in a highly ionized medium with a combined covering fraction of unity and a residual neutral gas column density in the ionized medium high enough to be optically thick to Ly α , but low enough to be at least partly transparent to LyC and undetected in Si ii. This suggests that star formation feedback and galaxy-scale interaction events play a major role in opening passageways for ionizing radiation through the neutral medium.

  17. Neutral ISM, Ly α , and Lyman-continuum in the Nearby Starburst Haro 11

    International Nuclear Information System (INIS)

    Rivera-Thorsen, T. Emil; Östlin, Göran; Hayes, Matthew; Puschnig, Johannes

    2017-01-01

    Star-forming galaxies are believed to be a major source of Lyman continuum (LyC) radiation responsible for reionizing the early universe. Direct observations of escaping ionizing radiation have however been sparse and with low escape fractions. In the local universe, only 10 emitters have been observed, with typical escape fractions of a few percent. The mechanisms regulating this escape need to be strongly evolving with redshift in order to account for the epoch of reionization. Gas content and star formation feedback are among the main suspects, known to both regulate neutral gas coverage and evolve with cosmic time. In this paper, we reanalyze Hubble Space Telescope ( HST )-Cosmic Origins Spectrograph (COS) spectrocopy of the first detected local LyC leaker, Haro 11. We examine the connection between LyC leakage and Ly α line shape, and feedback-influenced neutral interstellar medium (ISM) properties like kinematics and gas distribution. We discuss the two extremes of an optically thin, density bounded ISM and a riddled, optically thick, ionization bounded ISM, and how Haro 11 fits into theoretical predictions. We find that the most likely ISM model is a clumpy neutral medium embedded in a highly ionized medium with a combined covering fraction of unity and a residual neutral gas column density in the ionized medium high enough to be optically thick to Ly α , but low enough to be at least partly transparent to LyC and undetected in Si ii. This suggests that star formation feedback and galaxy-scale interaction events play a major role in opening passageways for ionizing radiation through the neutral medium.

  18. Impact of immune escape mutations on HIV-1 fitness in the context of the cognate transmitted/founder genome

    Directory of Open Access Journals (Sweden)

    Song Hongshuo

    2012-10-01

    Full Text Available Abstract Background A modest change in HIV-1 fitness can have a significant impact on viral quasispecies evolution and viral pathogenesis, transmission and disease progression. To determine the impact of immune escape mutations selected by cytotoxic T lymphocytes (CTL on viral fitness in the context of the cognate transmitted/founder (T/F genome, we developed a new competitive fitness assay using molecular clones of T/F genomes lacking exogenous genetic markers and a highly sensitive and precise parallel allele-specific sequencing (PASS method. Results The T/F and mutant viruses were competed in CD4+ T-cell enriched cultures, relative proportions of viruses were assayed after repeated cell-free passage, and fitness costs were estimated by mathematical modeling. Naturally occurring HLA B57-restricted mutations involving the TW10 epitope in Gag and two epitopes in Tat/Rev and Env were assessed independently and together. Compensatory mutations which restored viral replication fitness were also assessed. A principal TW10 escape mutation, T242N, led to a 42% reduction in replication fitness but V247I and G248A mutations in the same epitope restored fitness to wild-type levels. No fitness difference was observed between the T/F and a naturally selected variant carrying the early CTL escape mutation (R355K in Env and a reversion mutation in the Tat/Rev overlapping region. Conclusions These findings reveal a broad spectrum of fitness costs to CTL escape mutations in T/F viral genomes, similar to recent findings reported for neutralizing antibody escape mutations, and highlight the extraordinary plasticity and adaptive potential of the HIV-1 genome. Analysis of T/F genomes and their evolved progeny is a powerful approach for assessing the impact of composite mutational events on viral fitness.

  19. The adaptive significance of drought escape in Avena barbata, an annual grass.

    Science.gov (United States)

    Sherrard, Mark E; Maherali, Hafiz

    2006-12-01

    Drought strongly influences plant productivity, suggesting that water limitation has shaped the evolution of many plant physiological traits. One functional strategy that plants employ to cope with decreasing water availability is drought escape. For drought-escaping species, high metabolic activity (gas exchange) and rapid growth are hypothesized to confer a fitness advantage, because this enables a plant to complete its life cycle before the most intense period of drought. By growing an annual grass species (Avena barbata) under well-watered or water-limited conditions in a greenhouse, we directly tested whether high photosynthesis, increased stomatal opening, and early flowering are adaptive under drought. We measured phenotypic selection on instantaneous gas exchange and flowering time as well as the underlying biochemical traits that regulate photosynthesis. We found strong selection for earlier flowering in the dry environment, but no evidence that increased photosynthesis was adaptive under drought. Photosynthetic rate (A) and stomatal conductance (gs) were both adaptively neutral in the dry environment. Increased photosynthetic capacity (Amax) was maladaptive in the dry environment, perhaps because of the respiratory cost associated with maintaining excess enzyme and substrate capacity. There was no correlational selection on the combination of physiology and flowering time in the dry environment, suggesting that accelerated development and high gas exchange may not need to be tightly linked to promote drought escape. In contrast, there was selection for both high photosynthetic function (Amax and A) and early flowering in the well-watered environment. These combinations of traits may have been favored because they maximize both energy and time available for reproduction. Our results suggest that the benefit of increased photosynthesis for plant fitness may be strongest in the absence of drought stress.

  20. GREEN PEA GALAXIES REVEAL SECRETS OF Lyα ESCAPE

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Huan; Wang, Junxian [CAS Key Laboratory for Research in Galaxies and Cosmology, Department of Astronomy, University of Science and Technology of China (China); Malhotra, Sangeeta; Rhoads, James E. [Arizona State University, School of Earth and Space Exploration (United States); Gronke, Max; Dijkstra, Mark [Institute of Theoretical Astrophysics, University of Oslo (Norway); Jaskot, Anne [Smith College, Northampton, MA (United States); Zheng, Zhenya, E-mail: yanghuan@mail.ustc.edu.cn, E-mail: huan.y@asu.edu, E-mail: Sangeeta.Malhotra@asu.edu, E-mail: James.Rhoads@asu.edu [Pontificia Universidad Católica de Chile, Santiago (Chile)

    2016-04-01

    We analyze archival Lyα spectra of 12 “Green Pea” galaxies observed with the Hubble Space Telescope, model their Lyα profiles with radiative transfer models, and explore the dependence of the Lyα escape fraction on various properties. Green Pea galaxies are nearby compact starburst galaxies with [O iii] λ5007 equivalent widths (EWs) of hundreds of Å. All 12 Green Pea galaxies in our sample show Lyα lines in emission, with an Lyα EW distribution similar to high-redshift Lyα emitters. Combining the optical and UV spectra of Green Pea galaxies, we estimate their Lyα escape fractions and find correlations between Lyα escape fraction and kinematic features of Lyα profiles. The escape fraction of Lyα in these galaxies ranges from 1.4% to 67%. We also find that the Lyα escape fraction depends strongly on metallicity and moderately on dust extinction. We compare their high-quality Lyα profiles with single H i shell radiative transfer models and find that the Lyα escape fraction anticorrelates with the derived H i column densities. Single-shell models fit most Lyα profiles well, but not the ones with the highest escape fractions of Lyα. Our results suggest that low H i column density and low metallicity are essential for Lyα escape and make a galaxy an Lyα emitter.

  1. The influence of panic on the efficiency of escape

    Science.gov (United States)

    Shen, Jia-Quan; Wang, Xu-Wen; Jiang, Luo-Luo

    2018-02-01

    Whenever we (such as pedestrians) perceive a high density or imminent danger in a confined space, we tend to be panic, which can lead to severe injuries even in the absence of real dangers. Although it is difficult to measure panics in real conditions, we introduced a simple model to study the collective behaviors in condition of fire with dense smoke. Owing to blocking the sight with dense smoke, pedestrians in this condition have two strategies to escape: random-walking or walking along the wall. When the pedestrians are in moderate panic that mean the two types of behaviors are mixed(random-walking and walking along the wall). Our simulation results show that moderate panic, meaning that two escape strategies are mixed, reduces the escape time. In addition, the results indicate that moderate panic can improve the efficiency of escape, this theory also can be useful in a real escape situation. We hope that our research provides the theoretical understanding of underlying mechanisms of panic escape in the condition of poor sight.

  2. Dynamics of immune escape during HIV/SIV infection.

    Directory of Open Access Journals (Sweden)

    Christian L Althaus

    Full Text Available Several studies have shown that cytotoxic T lymphocytes (CTLs play an important role in controlling HIV/SIV infection. Notably, the observation of escape mutants suggests a selective pressure induced by the CTL response. However, it remains difficult to assess the definite role of the cellular immune response. We devise a computational model of HIV/SIV infection having a broad cellular immune response targeting different viral epitopes. The CTL clones are stimulated by viral antigen and interact with the virus population through cytotoxic killing of infected cells. Consequently, the virus population reacts through the acquisition of CTL escape mutations. Our model provides realistic virus dynamics and describes several experimental observations. We postulate that inter-clonal competition and immunodominance may be critical factors determining the sequential emergence of escapes. We show that even though the total killing induced by the CTL response can be high, escape rates against a single CTL clone are often slow and difficult to estimate from infrequent sequence measurements. Finally, our simulations show that a higher degree of immunodominance leads to more frequent escape with a reduced control of viral replication but a substantially impaired replicative capacity of the virus. This result suggests two strategies for vaccine design: Vaccines inducing a broad CTL response should decrease the viral load, whereas vaccines stimulating a narrow but dominant CTL response are likely to induce escape but may dramatically reduce the replicative capacity of the virus.

  3. Ultracold neutral plasmas

    Science.gov (United States)

    Lyon, M.; Rolston, S. L.

    2017-01-01

    By photoionizing samples of laser-cooled atoms with laser light tuned just above the ionization limit, plasmas can be created with electron and ion temperatures below 10 K. These ultracold neutral plasmas have extended the temperature bounds of plasma physics by two orders of magnitude. Table-top experiments, using many of the tools from atomic physics, allow for the study of plasma phenomena in this new regime with independent control over the density and temperature of the plasma through the excitation process. Characteristic of these systems is an inhomogeneous density profile, inherited from the density distribution of the laser-cooled neutral atom sample. Most work has dealt with unconfined plasmas in vacuum, which expand outward at velocities of order 100 m/s, governed by electron pressure, and with lifetimes of order 100 μs, limited by stray electric fields. Using detection of charged particles and optical detection techniques, a wide variety of properties and phenomena have been observed, including expansion dynamics, collective excitations in both the electrons and ions, and collisional properties. Through three-body recombination collisions, the plasmas rapidly form Rydberg atoms, and clouds of cold Rydberg atoms have been observed to spontaneously avalanche ionize to form plasmas. Of particular interest is the possibility of the formation of strongly coupled plasmas, where Coulomb forces dominate thermal motion and correlations become important. The strongest impediment to strong coupling is disorder-induced heating, a process in which Coulomb energy from an initially disordered sample is converted into thermal energy. This restricts electrons to a weakly coupled regime and leaves the ions barely within the strongly coupled regime. This review will give an overview of the field of ultracold neutral plasmas, from its inception in 1999 to current work, including efforts to increase strong coupling and effects on plasma properties due to strong coupling.

  4. ESCAPE to Reality, Post-Trial Outcomes in an ESCAPE Centre: A Retrospective Case-Control Study.

    Science.gov (United States)

    Nixon, Amy M; Jamison, Michael; Rennie, Ian M; Flynn, Peter A; Smyth, Graham; Wiggam, Ivan; Kerr, Enda; Fulton, Ailsa; Hunter, Annemarie; Burns, Paul A

    2018-01-01

    The Royal Victoria Hospital, Belfast provides the regional neuroendovascular service for Northern Ireland and was an enrolling centre for the ESCAPE endovascular stroke trial. Our aim was to assess outcomes for patients presenting with acute stroke following discontinuation of trial enrolment at our centre. We collected data on all patients presenting with acute stoke between Nov-1st-2014 and Oct-31st-2015 who received endovascular treatment or received IV thrombolysis (IV-tPA) alone. ESCAPE eligibility of each patient was assessed. Primary outcome was modified Rankin Score (mRS) at 3 months. 129 patients presented with acute stoke symptoms during the time period; 56/129 (43.4%) patients in the intervention group and 73/129 (56.5%) patients in the control group. In the interventional group, 42/56 (75%) were considered ESCAPE eligible and 14/56 (25%) were considered ESCAPE ineligible. 30/42 (71.4%) ESCAPE eligible patients had a positive functional outcome at 3 months compared to 9/14 (64.2%) ESCAPE ineligible patients. In the control group, 37 (50.7%) had identifiable thrombotic occlusion and 13/37 (35.1%) were considered eligible for intervention. 4/13 (30.8%) achieved functional independence (mRS<3) at 3 months.There was a statistically significant difference in functional independence in those who underwent endovascular therapy compared to the control group (p= 0.04). ESCAPE eligible patients in our centre had favourable outcome rates superior to the published trial data. ESCAPE ineligible patients tended to do slightly less well, but still better than the favourable outcome rates achieved with IVtPA alone. There is potentially a wide discordance between the threshold for futility and trial eligibility criteria when considering endovascular treatment for acute ischaemic stroke.

  5. CD8+ and CD4+ cytotoxic T cell escape mutations precede breakthrough SIVmac239 viremia in an elite controller

    Directory of Open Access Journals (Sweden)

    Burwitz Benjamin J

    2012-11-01

    Full Text Available Abstract Background Virus-specific T cells are critical components in the containment of immunodeficiency virus infections. While the protective role of CD8+ T cells is well established by studies of CD8+ T cell-mediated viral escape, it remains unknown if CD4+ T cells can also impose sufficient selective pressure on replicating virus to drive the emergence of high-frequency escape variants. Identifying a high frequency CD4+ T cell driven escape mutation would provide compelling evidence of direct immunological pressure mediated by these cells. Results Here, we studied a SIVmac239-infected elite controller rhesus macaque with a 1,000-fold spontaneous increase in plasma viral load that preceded disease progression and death from AIDS-related complications. We sequenced the viral genome pre- and post-breakthrough and demonstrate that CD8+ T cells drove the majority of the amino acid substitutions outside of Env. However, within a region of Gag p27CA targeted only by CD4+ T cells, we identified a unique post-breakthrough mutation, Gag D205E, which abrogated CD4+ T cell recognition. Further, we demonstrate that the Gag p27CA-specific CD4+ T cells exhibited cytolytic activity and that SIV bearing the Gag D205E mutation escapes this CD4+ T cell effector function ex vivo. Conclusions Cumulatively, these results confirm the importance of virus specific CD8+ T cells and demonstrate that CD4+ T cells can also exert significant selective pressure on immunodeficiency viruses in vivo during low-level viral replication. These results also suggest that further studies of CD4+ T cell escape should focus on cases of elite control with spontaneous viral breakthrough.

  6. RAMI Analyses of Heating Neutral Beam and Diagnostic Neutral Beam Systems for ITER

    Science.gov (United States)

    Chang, D. H.; Lee, S.; Hemsworth, R.; van Houtte, D.; Okayama, K.; Sagot, F.; Schunke, B.; Svensson, L.

    2011-09-01

    A RAMI (Reliability, Availability, Maintainability, Inspectability) analysis has been performed for the heating (& current drive) neutral beam (HNB) and diagnostic neutral beam (DNB) systems of the ITER device [1-3]. The objective of these analyses is to implement RAMI engineering requirements for design and testing to prepare a reliability-centred plan for commissioning, operation, and maintenance of the system in the framework of technical risk control to support the overall ITER Project. These RAMI requirements will correspond to the RAMI targets for the ITER project and the compensating provisions to reach them as deduced from the necessary actions to decrease the risk level of the function failure modes. The RAMI analyses results have to match with the procurement plan of the systems.

  7. RAMI Analyses of Heating Neutral Beam and Diagnostic Neutral Beam Systems for ITER

    International Nuclear Information System (INIS)

    Chang, D. H.; Lee, S.; Hemsworth, R.; Houtte, D. van; Okayama, K.; Sagot, F.; Schunke, B.; Svensson, L.

    2011-01-01

    A RAMI (Reliability, Availability, Maintainability, Inspectability) analysis has been performed for the heating (and current drive) neutral beam (HNB) and diagnostic neutral beam (DNB) systems of the ITER device. The objective of these analyses is to implement RAMI engineering requirements for design and testing to prepare a reliability-centred plan for commissioning, operation, and maintenance of the system in the framework of technical risk control to support the overall ITER Project. These RAMI requirements will correspond to the RAMI targets for the ITER project and the compensating provisions to reach them as deduced from the necessary actions to decrease the risk level of the function failure modes. The RAMI analyses results have to match with the procurement plan of the systems.

  8. To run or hide?: escape behaviour in a cryptic African snake | Maritz ...

    African Journals Online (AJOL)

    Optimal escape theory predicts that escape behaviour of an organism is best understood in terms of costs and benefits of escaping relative to risk of predation. However, risk of predation facing an organism is dependent on various biotic and abiotic factors. In order to better understand escape behaviour of an African snake, ...

  9. Fin-tail coordination during escape and predatory behavior in larval zebrafish.

    Directory of Open Access Journals (Sweden)

    Phil McClenahan

    Full Text Available Larval zebrafish innately perform a suite of behaviors that are tightly linked to their evolutionary past, notably escape from threatening stimuli and pursuit and capture of prey. These behaviors have been carefully examined in the past, but mostly with regard to the movements of the trunk and tail of the larvae. Here, we employ kinematics analyses to describe the movements of the pectoral fins during escape and predatory behavior. In accord with previous studies, we find roles for the pectoral fins in slow swimming and immediately after striking prey. We find novel roles for the pectoral fins in long-latency, but not in short-latency C-bends. We also observe fin movements that occur during orienting J-turns and S-starts that drive high-velocity predatory strikes. Finally, we find that the use of pectoral fins following a predatory strike is scaled to the velocity of the strike, supporting a role for the fins in braking. The implications of these results for central control of coordinated movements are discussed, and we hope that these results will provide baselines for future analyses of cross-body coordination using mutants, morphants, and transgenic approaches.

  10. Catch me if you can: Leukemia Escape after CD19-Directed T Cell Immunotherapies

    Directory of Open Access Journals (Sweden)

    Marco Ruella

    2016-01-01

    Full Text Available Immunotherapy is the revolution in cancer treatment of this last decade. Among multiple approaches able to harness the power of the immune system against cancer, T cell based immunotherapies represent one of the most successful examples. In particular, biotechnological engineering of protein structures, like the T cell receptor or the immunoglobulins, allowed the generation of synthetic peptides like chimeric antigen receptors and bispecific antibodies that are able to redirect non-tumor specific T cells to recognize and kill leukemic cells. The anti-CD19/CD3 bispecific antibody blinatumomab and anti-CD19 chimeric antigen receptor T cells (CART19 have produced deep responses in patients with relapsed and refractory B-cell acute leukemias. However, although the majority of these patients responds to anti-CD19 immunotherapy, a subset of them still relapses. Interestingly, a novel family of leukemia escape mechanisms has been described, all characterized by the apparent loss of CD19 on the surface of leukemic blasts. This extraordinary finding demonstrates the potent selective pressure of CART19/blinatumomab that drives extreme and specific escape strategies by leukemic blasts. Patients with CD19-negative relapsed leukemia have very poor prognosis and novel approaches to treat and ideally prevent antigen-loss are direly needed. In this review we discuss the incidence, mechanisms and therapeutic approaches for CD19-negative leukemia relapses occuring after CD19-directed T cell immunotherapies and present our future perspective.

  11. Both Neutralizing and Non-Neutralizing Human H7N9 Influenza Vaccine-Induced Monoclonal Antibodies Confer Protection.

    Science.gov (United States)

    Henry Dunand, Carole J; Leon, Paul E; Huang, Min; Choi, Angela; Chromikova, Veronika; Ho, Irvin Y; Tan, Gene S; Cruz, John; Hirsh, Ariana; Zheng, Nai-Ying; Mullarkey, Caitlin E; Ennis, Francis A; Terajima, Masanori; Treanor, John J; Topham, David J; Subbarao, Kanta; Palese, Peter; Krammer, Florian; Wilson, Patrick C

    2016-06-08

    Pathogenic H7N9 avian influenza viruses continue to represent a public health concern, and several candidate vaccines are currently being developed. It is vital to assess if protective antibodies are induced following vaccination and to characterize the diversity of epitopes targeted. Here we characterized the binding and functional properties of twelve H7-reactive human antibodies induced by a candidate A/Anhui/1/2013 (H7N9) vaccine. Both neutralizing and non-neutralizing antibodies protected mice in vivo during passive transfer challenge experiments. Mapping the H7 hemagglutinin antigenic sites by generating escape mutant variants against the neutralizing antibodies identified unique epitopes on the head and stalk domains. Further, the broadly cross-reactive non-neutralizing antibodies generated in this study were protective through Fc-mediated effector cell recruitment. These findings reveal important properties of vaccine-induced antibodies and provide a better understanding of the human monoclonal antibody response to influenza in the context of vaccines. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Cooperativity Enables Non-neutralizing Antibodies to Neutralize Ebolavirus

    Directory of Open Access Journals (Sweden)

    Katie A. Howell

    2017-04-01

    Full Text Available Drug combinations are synergistic when their combined efficacy exceeds the sum of the individual actions, but they rarely include ineffective drugs that become effective only in combination. We identified several “enabling pairs” of neutralizing and non-neutralizing anti-ebolavirus monoclonal antibodies, whose combination exhibited new functional profiles, including transforming a non-neutralizing antibody to a neutralizer. Sub-neutralizing concentrations of antibodies 2G4 or m8C4 enabled non-neutralizing antibody FVM09 (IC50 >1 μM to exhibit potent neutralization (IC50 1–10 nM. While FVM09 or m8C4 alone failed to protect Ebola-virus-infected mice, a combination of the two antibodies provided 100% protection. Furthermore, non-neutralizers FVM09 and FVM02 exponentially enhanced the potency of two neutralizing antibodies against both Ebola and Sudan viruses. We identified a hotspot for the binding of these enabling antibody pairs near the interface of the glycan cap and GP2. Enabling cooperativity may be an underappreciated phenomenon for viruses, with implications for the design and development of immunotherapeutics and vaccines.

  13. Neutral polypropylene laser welding

    Science.gov (United States)

    Mandolfino, Chiara; Lertora, Enrico; Gambaro, Carla

    2016-10-01

    The joining of polymeric materials is a technology used in many industrial applications, from transport to telecommunications and the medical sector. A new technology for the joining of polymers is the laser welding process. In particular, fibre laser welding is a flexible technology which allows high process speed and the realization of good quality joints. Despite its application becoming more widespread in the production of assemblies of high precision, the application of laser technology for the welding of polymers has not been the subject of many studies up to now. This study focused on the welding of neutral polypropylene. The window process parameter was identified, without the use of additives to increase radiation absorption, and a mechanical characterization was conducted in order to evaluate the quality of the joints realized.

  14. Mod en neutral seksualitet!

    DEFF Research Database (Denmark)

    Leer, Jonatan

    2013-01-01

    Towards a Neutral Sexuality! or Roland Barthes as a Queer Thinker? This article argues that the work of Roland Barthes has interesting perspectives in common with the queer theory. This argument will be put forward by using his concept of ‘the neutral’ that Barthes defines as “that which outplays...... the paradigm”. This notion was presented at a series of lectures at Collège de France in 1977. Through a reading of Barthes’s autobiography, Roland Barthes par Roland Barthes (1975), the article demonstrates how Barthes in this text tries to outplay the paradigms that rules over the hegemonic understanding...... theory” in the late 1970’s that beside Barthes includes Jean Baudrillard....

  15. Neutral Kaon Spectrometer 2

    Science.gov (United States)

    Kaneta, M.; Beckford, B.; Fujii, T.; Fujii, Y.; Futatsukawa, K.; Han, Y. C.; Hashimoto, O.; Hirose, K.; Ishikawa, T.; Kanda, H.; Kimura, C.; Maeda, K.; Nakamura, S. N.; Suzuki, K.; Tsukada, K.; Yamamoto, F.; Yamazaki, H.

    2018-04-01

    A large-acceptance spectrometer, Neutral Kaon Spectrometer 2 (NKS2), was newly constructed to explore various photoproduction reactions in the gigaelectronvolt region at the Laboratory of Nuclear Science (LNS, currently ELPH), Tohoku University. The spectrometer consisted of a dipole magnet, drift chambers, and plastic scintillation counters. NKS2 was designed to separate pions and protons in a momentum range of less than 1 GeV/ c, and was placed in a tagged photon beamline. A cryogenic H2/D2 target fitted to the spectrometer were designed. The design and performance of the detectors are described. The results of the NKS2 experiment on analyzing strangeness photoproduction data using a 0.8-1.1 GeV tagged photon beam are also presented.

  16. Spectroscopy of neutral radium

    Energy Technology Data Exchange (ETDEWEB)

    Mol, Aran; De, Subhadeep; Jungmann, Klaus; Wilschut, Hans; Willmann, Lorenz [KVI, University of Groningen, Groningen (Netherlands)

    2008-07-01

    The heavy alkaline earth atoms radium is uniquely sensitive towards parity and time reversal symmetry violations due to a large enhancement of an intrinsic permanent electric dipole moment of the nucleous or the electron. Furthermore, radium is sensitive to atomic parity violation and the nuclear anapole moment. To prepare such experiments spectroscopy of relevant atomic states need to be done. At a later stage we will build a neutral atom trap for radium. We have built an atomic beam of the short lived isotope {sup 225}Ra with a flux of several 10{sup 4} atoms/sec. We are preparing the laser spectroscopy using this beam setup. In the preparation for efficient laser cooling and trapping we have successfully trapped barium, which is similar in it's requirements for laser cooling. The techniques which we have developed with barium can be used to trap rare radium isotopes. We report on the progress of the experiments.

  17. ESCAPE DYNAMICS AS A WAY TO DESCRIBE ECONOMIC PHENOMENA

    Directory of Open Access Journals (Sweden)

    Bogomolova A. S.

    2017-06-01

    Full Text Available This paper presents the review of issues and approaches to the analysis of escape dynamics in economic models with constant gain adaptive learning which is used to model and describe the behavior of various (macroeconomic as well as microeconomic variables in diverse economic phenomena such as currency crises, inflation episodes, endogenous collusion in oligopoly, and cycles of economic activity. This review considers and contrasts two currently existing approaches to the analysis of escape dynamics: the discrete-time approach employed, for example, by Cho, Williams and Sargent (2002, and the continuous-time approach proposed by Kasa (2004 and extended recently by Kolyuzhnov, Bogomolova and Slobodyan (2014, stressing the advantages of the latter. The continuous-time approach is based on the application of the results of the continuous-time version of the large deviations theory to the diffusion approximation of the original discrete-time dynamics under learning. Escape dynamics is characterized by analytically deriving the most probable escape point and mean escape time. The paper provides an example of the continuous-time approach applied to the Phelps problem of a government controlling inflation while adaptively learning the approximate Phillips curve.

  18. History of oxygen and carbon escape from the Martian atmosphere

    Science.gov (United States)

    Luhmann, J. G.; Zhang, M. H. G.; Johnson, R. E.; Bougher, S. W.; Nagy, A. F.

    1992-01-01

    A fraction of the oxygen in the Martian atmosphere continually escapes to space because dissociative recombination of the O2(+) ions in the ionosphere can impart sufficient energy to the product O atoms. In addition, ionization of the extended atomic oxygen corona resulting from the above process adds to escape since the solar wind can carry away O(+) ions born above a few hundred km altitude. A further by-product of this ion-pickup by the solar wind is an additional population of escaping oxygen atoms that are sputtered from the atmosphere near the exobase by pickup ions that are on reentry rather than escaping trajectories. This sputtering process can also remove carbon in the form of intact or dissociated CO2 since all atoms and molecules in the 'target' gas are subject to the collisional energy transfer that characterizes sputtering. We have estimated the present rates of escape of oxygen and carbon due to these mechanisms, as well as the rates at several epochs in the history of the solar system.

  19. Escaping domestic violence: A qualitative study of women who left their abusive husbands

    Directory of Open Access Journals (Sweden)

    Surianti Sukeri, PhD

    2017-12-01

    Full Text Available Objectives: This qualitative study aims to discover the factors that influenced the decisions of women who successfully escaped domestic violence by attaining a divorce. Methods: In-depth interviews were conducted with 17 women, ages 21-56 who were either divorced or currently in the process of getting divorced in Kelantan, Malaysia. Results: Several themes emerged, indicating the following five reasons for divorce: 1 reaching the point of ultimatum, 2 having adequate support pre- and post-divorce, 3 concern for children's welfare, 4 seeking financial independence, and 5 fear of harm. Conclusion: The identification of the driving factors for divorce may spark a change in our society's mindset to empower female divorcees and allow them to lead happy, abuse-free lives. Keywords: Divorce, Domestic violence, In-depth interview, Malaysia

  20. Passive Facebook use, Facebook addiction, and associations with escapism: an experimental vignette study

    OpenAIRE

    Young, LN; Kuss, DJ; Griffiths, MD; Howard, CJ

    2017-01-01

    There is relatively little research considering motivations of passive Facebook use. However, research regarding motivations of general Facebook use indicates that people use Facebook to escape – and that escapism may motivate passive Facebook use. Research also suggests that using Facebook to escape is associated with Facebook addiction. Using an experimental vignette design, the present research investigated whether passive Facebook use is motivated by escapism and whether this escape motiv...

  1. Amino Acid Changes in the HIV-1 gp41 Membrane Proximal Region Control Virus Neutralization Sensitivity.

    Science.gov (United States)

    Bradley, Todd; Trama, Ashley; Tumba, Nancy; Gray, Elin; Lu, Xiaozhi; Madani, Navid; Jahanbakhsh, Fatemeh; Eaton, Amanda; Xia, Shi-Mao; Parks, Robert; Lloyd, Krissey E; Sutherland, Laura L; Scearce, Richard M; Bowman, Cindy M; Barnett, Susan; Abdool-Karim, Salim S; Boyd, Scott D; Melillo, Bruno; Smith, Amos B; Sodroski, Joseph; Kepler, Thomas B; Alam, S Munir; Gao, Feng; Bonsignori, Mattia; Liao, Hua-Xin; Moody, M Anthony; Montefiori, David; Santra, Sampa; Morris, Lynn; Haynes, Barton F

    2016-10-01

    Most HIV-1 vaccines elicit neutralizing antibodies that are active against highly sensitive (tier-1) viruses or rare cases of vaccine-matched neutralization-resistant (tier-2) viruses, but no vaccine has induced antibodies that can broadly neutralize heterologous tier-2 viruses. In this study, we isolated antibodies from an HIV-1-infected individual that targeted the gp41 membrane-proximal external region (MPER) that may have selected single-residue changes in viral variants in the MPER that resulted in neutralization sensitivity to antibodies targeting distal epitopes on the HIV-1 Env. Similarly, a single change in the MPER in a second virus from another infected-individual also conferred enhanced neutralization sensitivity. These gp41 single-residue changes thus transformed tier-2 viruses into tier-1 viruses that were sensitive to vaccine-elicited tier-1 neutralizing antibodies. These data demonstrate that Env amino acid changes within the MPER bnAb epitope of naturally-selected escape viruses can increase neutralization sensitivity to multiple types of neutralizing antibodies, and underscore the critical importance of the MPER for maintaining the integrity of the tier-2 HIV-1 trimer. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  2. Behavior of Ants Escaping from a Single-Exit Room.

    Directory of Open Access Journals (Sweden)

    Shujie Wang

    Full Text Available To study the rules of ant behavior and group-formation phenomena, we examined the behaviors of Camponotus japonicus, a species of large ant, in a range of situations. For these experiments, ants were placed inside a rectangular chamber with a single exit that also contained a filter paper soaked in citronella oil, a powerful repellent. The ants formed several groups as they moved toward the exit to escape. We measured the time intervals between individual escapes in six versions of the experiment, each containing an exit of a different width, to quantify the movement of the groups. As the ants exited the chamber, the time intervals between individual escapes changed and the frequency distribution of the time intervals exhibited exponential decay. We also investigated the relationship between the number of ants in a group and the group flow rate.

  3. Escaping and Falling into Poverty in India Today.

    Science.gov (United States)

    Thorat, Amit; Vanneman, Reeve; Desai, Sonalde; Dubey, Amaresh

    2017-05-01

    The study examines the dynamic nature of movements into and out of poverty over a period when poverty has fallen substantially in India. The analysis identifies people who escaped poverty and those who fell into it over the period 2005 to 2012. The analysis identifies people who escaped poverty and those who fell into it over the period 2005 to 2012. Using panel data from the India Human Development Survey for 2005 and 2012, we find that the risks of marginalized communities such as Dalits and Adivasis of falling into or remaining in poverty were higher than those for more privileged groups. Some, but not all of these higher risks are explained by educational, financial, and social disadvantages of these groups in 2005. Results from a logistic regression show that some factors that help people escape poverty differ from those that push people into it and that the strength of their effects varies.

  4. Escape panels in trawls – a consistent management tool?

    DEFF Research Database (Denmark)

    Krag, Ludvig Ahm; Herrmann, Bent; Feekings, Jordan P.

    2016-01-01

    gears are often developed in collaboration between scientists and fishers. Part of the development is a controlled scientific test documenting the selectivity effect. In this study, we compared two versions of a mandatory escape panel that were introduced into the mixed species fishery in the Skagerrak...... vertical distance between the upper panel (escape panel) and the bottom panel compared to the pre-version. Both designs are legal and considered identical. The results of this study showed significantly higher catches (lower selectivity) for the post-version for all five species examined; cod (Gadus morhua......), saithe (Pollachius virens), haddock (Melanogrammus aeglefinus), plaice (Pleuronectes platessa) and Norway lobster (Nephrops norvegicus). Thus the modification by fishers of certain gear properties not specified in the legislation can significantly influence the efficiency of an escape panel. We discuss...

  5. LADEE Neutral Mass Spectrometer Data

    Data.gov (United States)

    National Aeronautics and Space Administration — This bundle contains the data collected by the Neutral Mass Spectrometer (NMS) instrument aboard the Lunar Atmosphere and Dust Environment Explorer (LADEE)...

  6. Dementia and driving

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000028.htm Dementia and driving To use the sharing features on ... please enable JavaScript. If your loved one has dementia , deciding when they can no longer drive may ...

  7. Control rod drives

    International Nuclear Information System (INIS)

    Shimano, Kunio; Nakamura, Akira; Mizuguchi, Koji; Sakai, Kazuhito; Mitsui, Hisayasu.

    1994-01-01

    The present invention concerns upper-built-in type control rod drives of a BWR type reactor. Namely, high temperature linear motor driving type control rod drives are disposed in an upper space of the reactor pressure vessel, which generates electromagnetic power. In usual driving of control rods, driving shafts connected with control rods by a high temperature linear motor driving system comprising a driving shaft having an iron core inserted therein and electromagnetic coils is vertically moved to insert/withdraw the control rods to and from the reactor core. Upon occurrence of reactor scram, electric power source is interrupted, and the control rods are rapidly inserted to the reactor core. According to the present invention, since the control rod drives are disposed in the space above the reactor pressure vessel, pipelines or equipments passing through the bottom of the reactor pressure vessel can be saved. As a result, operation for maintenance and inspection is facilitated. (I.S.)

  8. Gear bearing drive

    Science.gov (United States)

    Weinberg, Brian (Inventor); Mavroidis, Constantinos (Inventor); Vranish, John M. (Inventor)

    2011-01-01

    A gear bearing drive provides a compact mechanism that operates as an actuator providing torque and as a joint providing support. The drive includes a gear arrangement integrating an external rotor DC motor within a sun gear. Locking surfaces maintain the components of the drive in alignment and provide support for axial loads and moments. The gear bearing drive has a variety of applications, including as a joint in robotic arms and prosthetic limbs.

  9. SOYUZ escape trajectory analysis from Space Station Freedom

    Science.gov (United States)

    Heck, Michael L.

    1993-01-01

    It has been proposed to utilize the Russian built SOYUZ as an assured crew return vehicle (ACRV) for Space Station Freedom. Three departure directions (nadir, zenith, minus velocity) are evaluated to determine escape path clearances. In addition, the effects of the following parameters were also evaluated: delta-V magnitude, configuration dependent ballistic coefficients, atmospheric density, Freedom attitude control, and canted docking adaptors. The primary factor influencing the escape trajectory was station contingency attitude rate. The nadir and zenith departures were preferable to minus velocity. The impact of atmospheric density and relative ballistic coefficients was minimal.

  10. Case of escape in cassava, Manihot esculenta Crantz.

    Science.gov (United States)

    Nassar, N M A; Mendonza, M

    2017-02-08

    Two cassava escapes where collected from cultivated fields near natural habitat in Bolivia. They are described morphologically and analyzed cytogenetically in this study. It is suggested that they are the product of backcrosses of cassava interspecific hybrids with the cultigen itself, and that selective conditions have developed in which certain forms of cassava segregates have adapted to grow wildly in natural habitats near cassava fields. These segregates may hybridize with cultivated cassava upon coming in contact with such varieties. Because these escapes have incorporated useful genes from the wild into their genetic structure, they could be used for cassava improvement since their genetic barriers with other forms of cassava are very weak.

  11. Rapid endosomal escape of prickly nanodiamonds: implications for gene delivery

    Science.gov (United States)

    Chu, Zhiqin; Miu, Kaikei; Lung, Pingsai; Zhang, Silu; Zhao, Saisai; Chang, Huan-Cheng; Lin, Ge; Li, Quan

    2015-06-01

    The prickly nanodiamonds easily entered cells via endocytosis followed by unique intracellular translocation characteristics—quick endosomal escape followed by stable residence in cytoplasm. Endosomal membrane rupturing is identified as the major route of nanodiamonds’ escaping the vesicle confinement and to the cytoplasm. Little cytotoxicity is observed to associate with the nanodiamonds’ cytosolic release. Such features enable its application for gene delivery, which requires both effective cellular uptake and cytosolic release of the gene. Taking green fluorescent protein gene as an example, we demonstrate the successful cytosolic delivery and expression of such a gene using the prickly nanodiamonds as carrier.

  12. Rapid endosomal escape of prickly nanodiamonds: implications for gene delivery.

    Science.gov (United States)

    Chu, Zhiqin; Miu, Kaikei; Lung, Pingsai; Zhang, Silu; Zhao, Saisai; Chang, Huan-Cheng; Lin, Ge; Li, Quan

    2015-06-30

    The prickly nanodiamonds easily entered cells via endocytosis followed by unique intracellular translocation characteristics—quick endosomal escape followed by stable residence in cytoplasm. Endosomal membrane rupturing is identified as the major route of nanodiamonds' escaping the vesicle confinement and to the cytoplasm. Little cytotoxicity is observed to associate with the nanodiamonds' cytosolic release. Such features enable its application for gene delivery, which requires both effective cellular uptake and cytosolic release of the gene. Taking green fluorescent protein gene as an example, we demonstrate the successful cytosolic delivery and expression of such a gene using the prickly nanodiamonds as carrier.

  13. CO2-neutral fuels

    Science.gov (United States)

    Goede, A. P. H.

    2015-08-01

    The need for storage of renewable energy (RE) generated by photovoltaic, concentrated solar and wind arises from the fact that supply and demand are ill-matched both geographically and temporarily. This already causes problems of overcapacity and grid congestion in countries where the fraction of RE exceeds the 20% level. A system approach is needed, which focusses not only on the energy source, but includes conversion, storage, transport, distribution, use and, last but not least, the recycling of waste. Furthermore, there is a need for more flexibility in the energy system, rather than relying on electrification, integration with other energy systems, for example the gas network, would yield a system less vulnerable to failure and better adapted to requirements. For example, long-term large-scale storage of electrical energy is limited by capacity, yet needed to cover weekly to seasonal demand. This limitation can be overcome by coupling the electricity net to the gas system, considering the fact that the Dutch gas network alone has a storage capacity of 552 TWh, sufficient to cover the entire EU energy demand for over a month. This lecture explores energy storage in chemicals bonds. The focus is on chemicals other than hydrogen, taking advantage of the higher volumetric energy density of hydrocarbons, in this case methane, which has an approximate 3.5 times higher volumetric energy density. More importantly, it allows the ready use of existing gas infrastructure for energy storage, transport and distribution. Intermittent wind electricity generated is converted into synthetic methane, the Power to Gas (P2G) scheme, by splitting feedstock CO2 and H2O into synthesis gas, a mixture of CO and H2. Syngas plays a central role in the synthesis of a range of hydrocarbon products, including methane, diesel and dimethyl ether. The splitting is accomplished by innovative means; plasmolysis and high-temperature solid oxygen electrolysis. A CO2-neutral fuel cycle is

  14. CO2-neutral fuels

    Directory of Open Access Journals (Sweden)

    Goede A. P. H.

    2015-01-01

    Full Text Available The need for storage of renewable energy (RE generated by photovoltaic, concentrated solar and wind arises from the fact that supply and demand are ill-matched both geographically and temporarily. This already causes problems of overcapacity and grid congestion in countries where the fraction of RE exceeds the 20% level. A system approach is needed, which focusses not only on the energy source, but includes conversion, storage, transport, distribution, use and, last but not least, the recycling of waste. Furthermore, there is a need for more flexibility in the energy system, rather than relying on electrification, integration with other energy systems, for example the gas network, would yield a system less vulnerable to failure and better adapted to requirements. For example, long-term large-scale storage of electrical energy is limited by capacity, yet needed to cover weekly to seasonal demand. This limitation can be overcome by coupling the electricity net to the gas system, considering the fact that the Dutch gas network alone has a storage capacity of 552 TWh, sufficient to cover the entire EU energy demand for over a month. This lecture explores energy storage in chemicals bonds. The focus is on chemicals other than hydrogen, taking advantage of the higher volumetric energy density of hydrocarbons, in this case methane, which has an approximate 3.5 times higher volumetric energy density. More importantly, it allows the ready use of existing gas infrastructure for energy storage, transport and distribution. Intermittent wind electricity generated is converted into synthetic methane, the Power to Gas (P2G scheme, by splitting feedstock CO2 and H2O into synthesis gas, a mixture of CO and H2. Syngas plays a central role in the synthesis of a range of hydrocarbon products, including methane, diesel and dimethyl ether. The splitting is accomplished by innovative means; plasmolysis and high-temperature solid oxygen electrolysis. A CO2-neutral fuel

  15. Simple Driving Techniques

    DEFF Research Database (Denmark)

    Rosendahl, Mads

    2002-01-01

    -like language. Our aim is to extract a simple notion of driving and show that even in this tamed form it has much of the power of more general notions of driving. Our driving technique may be used to simplify functional programs which use function composition and will often be able to remove intermediate data...

  16. The DYNAMO Orbiter Project: High Resolution Mapping of Gravity/Magnetic Fields and In Situ Investigation of Mars Atmospheric Escape

    Science.gov (United States)

    Smrekar, S.; Chassefiere, E.; Forget, F.; Reme, H.; Mazelle, C.; Blelly, P. -L.; Acuna, M.; Connerney, J.; Purucker, M.; Lin, R.

    2000-01-01

    Dynamo is a small Mars orbiter planned to be launched in 2005 or 2007, in the frame of the NASA/CNES Mars exploration program. It is aimed at improving gravity and magnetic field resolution, in order to better understand the magnetic, geologic and thermal history of Mars, and at characterizing current atmospheric escape, which is still poorly constrained. These objectives are achieved by using a low periapsis orbit, similar to the one used by the Mars Global Surveyor spacecraft during its aerobraking phases. The proposed periapsis altitude for Dynamo of 120-130 km, coupled with the global distribution of periapses to be obtained during one Martian year of operation, through about 5000 low passes, will produce a magnetic/gravity field data set with approximately five times the spatial resolution of MGS. Low periapsis provides a unique opportunity to investigate the chemical and dynamical properties of the deep ionosphere, thermosphere, and the interaction between the atmosphere and the solar wind, therefore atmospheric escape, which may have played a crucial role in removing atmosphere, and water, from the planet. There is much room for debate on the importance of current atmosphere escape processes in the evolution of the Martian atmosphere, as early "exotic" processes including hydrodynamic escape and impact erosion are traditionally invoked to explain the apparent sparse inventory of present-day volatiles. Yet, the combination of low surface gravity and the absence of a substantial internally generated magnetic field have undeniable effects on what we observe today. In addition to the current losses in the forms of Jeans and photochemical escape of neutrals, there are solar wind interaction-related erosion mechanisms because the upper atmosphere is directly exposed to the solar wind. The solar wind related loss rates, while now comparable to those of a modest comet, nonetheless occur continuously, with the intriguing possibility of important cumulative and

  17. Electromagnetic radiation optimum neutralizer

    International Nuclear Information System (INIS)

    Smirnov, Igor

    2002-01-01

    This particular article relates to subtle electrical effects, and provides some evidence of a fundamental nature on how subtle low frequency electromagnetic fields might be utilized to protect human body against harmful effects of high frequencies electromagnetic radiation. I have focused my efforts on definite polar polymer compound named EMRON which is patented in the USA. This polar polymer compound can be excited by external high frequencies electromagnetic fields to generate subtle low frequency oscillations that are beneficial for cellular life structures. This concept is based on the possibility of existence of resonance phenomenon between polar polymers and biopolymers such as proteins, nucleic acids, lipids, etc. Low frequency patterns generated by defined polar polymer compound can interact with biostructures and transmit the signals that support and improve cellular functions in the body. The mechanism of this process was confirmed by number of studies. The animal (including human) brain is affected by electromagnetic waves to the extent that production of Alpha or Theta waves can be directly induced into brain by carrying an ELF (extremely low frequency, 5-12 Hz) signal on a microwave carrier frequency. EMRON does not reduce the power of electromagnetic fields. It 'shields' the cellular structures of the body against the harmful effects of EMR. The radiation is still entering the body but the neutralizing effect of EMRON renders the radiation harmless

  18. A mechanistic understanding of allosteric immune escape pathways in the HIV-1 envelope glycoprotein.

    Directory of Open Access Journals (Sweden)

    Anurag Sethi

    Full Text Available The HIV-1 envelope (Env spike, which consists of a compact, heterodimeric trimer of the glycoproteins gp120 and gp41, is the target of neutralizing antibodies. However, the high mutation rate of HIV-1 and plasticity of Env facilitates viral evasion from neutralizing antibodies through various mechanisms. Mutations that are distant from the antibody binding site can lead to escape, probably by changing the conformation or dynamics of Env; however, these changes are difficult to identify and define mechanistically. Here we describe a network analysis-based approach to identify potential allosteric immune evasion mechanisms using three known HIV-1 Env gp120 protein structures from two different clades, B and C. First, correlation and principal component analyses of molecular dynamics (MD simulations identified a high degree of long-distance coupled motions that exist between functionally distant regions within the intrinsic dynamics of the gp120 core, supporting the presence of long-distance communication in the protein. Then, by integrating MD simulations with network theory, we identified the optimal and suboptimal communication pathways and modules within the gp120 core. The results unveil both strain-dependent and -independent characteristics of the communication pathways in gp120. We show that within the context of three structurally homologous gp120 cores, the optimal pathway for communication is sequence sensitive, i.e. a suboptimal pathway in one strain becomes the optimal pathway in another strain. Yet the identification of conserved elements within these communication pathways, termed inter-modular hotspots, could present a new opportunity for immunogen design, as this could be an additional mechanism that HIV-1 uses to shield vulnerable antibody targets in Env that induce neutralizing antibody breadth.

  19. High performance AC drives

    CERN Document Server

    Ahmad, Mukhtar

    2010-01-01

    This book presents a comprehensive view of high performance ac drives. It may be considered as both a text book for graduate students and as an up-to-date monograph. It may also be used by R & D professionals involved in the improvement of performance of drives in the industries. The book will also be beneficial to the researchers pursuing work on multiphase drives as well as sensorless and direct torque control of electric drives since up-to date references in these topics are provided. It will also provide few examples of modeling, analysis and control of electric drives using MATLAB/SIMULIN

  20. Beam heating of the neutralizer gas of neutral beam injectors

    International Nuclear Information System (INIS)

    Ott, W.

    1989-02-01

    It was shown by Pamela that the target thickness of the neutralizer gas in neutral beam injectors is smaller than to be expected from gas flow calculations. He explained his findings by direct and indirect beam heating of the gas and a consequent flow acceleration. The role of the neutralizer plasma electrons in the gas heating scenario is reconsidered here. To this end the particle and energy balances of the electrons are solved with allowance for ionization and dissociation of the gas by the electrons. It is shown that the direct contribution of the electrons to heating is not dominant. Their indirect contribution via ion acceleration in the space charge sheath in front of the walls is usually stronger. Methods to increase the neutralizer target thickness are investigated. They are essentially (1) structuring the neutralizer surface in order to reduce the reflection of medium energy particles and to increase the gas accommodation, (2) cooling down the neutralizer to LN 2 -temperature. The scaling of the target thickness with various parameters is investigated and compared with 'cold' flow. Initially it was assumed that the neutralizer plasma electrons are hot and able to excite Balmer alpha radiation in collisions with H 2 molecules. The investigation shows that the electrons must be cold instead (T e + 2 and H + 3 ions leading to excited hydrogen atoms. (orig.)

  1. Neutral and alkaline cellulases: Production, engineering, and applications.

    Science.gov (United States)

    Ben Hmad, Ines; Gargouri, Ali

    2017-08-01

    Neutral and alkaline cellulases from microorganisms constitute a major group of the industrial enzymes and find applications in various industries. Screening is the important ways to get novel cellulases. Most fungal cellulases have acidic pH optima, except some fungi like Humicola insolens species. However, new applications require the use of neutral and alkaline cellulases in food, brewery and wine, animal feed, textile and laundry, pulp and paper industries, agriculture as well in scientific research purposes. Indeed, the demand for these enzymes is growing more rapidly than ever before, and becomes the driving force for research on engineering the cellulolytic enzymes. Here, we present an overview of the biotechnological research for neutral and alkaline cellulases. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Predator escape tactics in birds : linking ecology and aerodynamics

    NARCIS (Netherlands)

    van den Hout, Piet J.; Mathot, Kimberley J.; Maas, Leo R. M.; Piersma, Theunis

    2010-01-01

    In most birds, flight is the most important means of escape from predators. Impaired flight abilities due to increased wing loading may increase vulnerability to predation. To compensate for an increase in wing loading, birds are able to independently decrease body mass (BM) or increase pectoral

  3. Escape angles in bulk chi((2)) soliton interactions

    DEFF Research Database (Denmark)

    Johansen, Steffen Kjær; Bang, Ole; Sørensen, Mads Peter

    2002-01-01

    We develop a theory for nonplanar interaction between two identical type I spatial solitons propagating at opposite, but arbitrary transverse angles in quadratic nonlinear (or so-called chi((2))) bulk, media. We predict quantitatively the outwards escape angle, below which the solitons turn around...

  4. Molecular strategies to design an escape-proof antiviral therapy

    NARCIS (Netherlands)

    Berkhout, Ben; Sanders, Rogier W.

    2011-01-01

    Two antiviral approaches against the human immunodeficiency virus type 1 (HIV-1) were presented at the Antivirals Congress in Amsterdam. The common theme among these two separate therapeutic research lines is the wish to develop a durable therapy that prevents viral escape. We will present a brief

  5. Determination of forage escape protein value with in situ and ...

    African Journals Online (AJOL)

    This study was carried out to compare in situ and in vitro enzyme techniques for determining estimates of forage escape proteins. Eight forages (vetch hay, wheat silage, corn silage, wheat hay, grass hay, lentil straw, triticale hay and alfalfa hay) were used as feed materials. During 70 h, incubation with enzyme method had ...

  6. Escaping Embarrassment: Face-Work in the Rap Cipher

    Science.gov (United States)

    Lee, Jooyoung

    2009-01-01

    How do individuals escape embarrassing moments in interaction? Drawing from ethnographic fieldwork, in-depth interviews, and video recordings of weekly street corner ciphers (impromptu rap sessions), this paper expands Goffman's theory of defensive and protective face-work. The findings reveal formulaic and indirect dimensions of face-work. First,…

  7. 46 CFR 169.313 - Means of escape.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Means of escape. 169.313 Section 169.313 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Construction... apart, uniform for the length of the ladder; (3) At least 3 inches from the nearest permanent object in...

  8. A Structural Soundness Proof for Shivers's Escape Technique

    DEFF Research Database (Denmark)

    Midtgaard, Jan; Adams, Michael D.; Matthew, Might

    2012-01-01

    Shivers’s escape technique enables one to analyse the control flow of higher-order program fragments. It is widely used, but its soundness has never been proven. In this paper, we present the first soundness proof for the technique. Our proof is structured as a composition of Galois connections...

  9. 46 CFR 108.445 - Alarm and means of escape.

    Science.gov (United States)

    2010-10-01

    ... AND EQUIPMENT Fire Extinguishing Systems Fixed Carbon Dioxide Fire Extinguishing Systems § 108.445 Alarm and means of escape. (a) Each CO2 system that has a supply of more than 136 kilograms (300 pounds) of CO2, except a system that protects a tank, must have an alarm that sounds for at least 20 seconds...

  10. The great escape - AIDS viruses and immune control.

    Science.gov (United States)

    Goulder, P J; Walker, B D

    1999-11-01

    Many studies have been designed to address the role of CTL immune escape in HIV-1 infection, but have not given conclusive answers. Now, an elegant longitudinal analysis clearly demonstrates that progression to disease in SIV-infected macaques is associated with evasion of the CTL response (pages 1270-1276).

  11. Danger detection and escape behaviour in wood crickets.

    Science.gov (United States)

    Dupuy, Fabienne; Casas, Jérôme; Body, Mélanie; Lazzari, Claudio R

    2011-07-01

    The wind-sensitive cercal system of Orthopteroid insects that mediates the detection of the approach of a predator is a very sensitive sensory system. It has been intensively analysed from a behavioural and neurobiological point of view, and constitutes a classical model system in neuroethology. The escape behaviour is triggered in orthopteroids by the detection of air-currents produced by approaching objects, allowing these insects to keep away from potential dangers. Nevertheless, escape behaviour has not been studied in terms of success. Moreover, an attacking predator is more than "air movement", it is also a visible moving entity. The sensory basis of predator detection is thus probably more complex than the perception of air movement by the cerci. We have used a piston mimicking an attacking running predator for a quantitative evaluation of the escape behaviour of wood crickets Nemobius sylvestris. The movement of the piston not only generates air movement, but it can be seen by the insect and can touch it as a natural predator. This procedure allowed us to study the escape behaviour in terms of detection and also in terms of success. Our results showed that 5-52% of crickets that detected the piston thrust were indeed touched. Crickets escaped to stimulation from behind better than to a stimulation from the front, even though they detected the approaching object similarly in both cases. After cerci ablation, 48% crickets were still able to detect a piston approaching from behind (compared with 79% of detection in intact insects) and 24% crickets escaped successfully (compared with 62% in the case of intact insects). So, cerci play a major role in the detection of an approaching object but other mechanoreceptors or sensory modalities are implicated in this detection. It is not possible to assure that other sensory modalities participate (in the case of intact animals) in the behaviour; rather, than in the absence of cerci other sensory modalities can

  12. Hepatitis C Virus Evasion Mechanisms from Neutralizing Antibodies

    Directory of Open Access Journals (Sweden)

    Arvind H. Patel

    2011-11-01

    Full Text Available Hepatitis C virus (HCV represents a major public health problem, affecting 3% of the world’s population. The majority of infected individuals develop chronic hepatitis, which can progress to cirrhosis and hepatocellular carcinoma. To date, a vaccine is not available and current therapy is limited by resistance, adverse effects and high costs. Although it is very well established that cell-mediated immunity is necessary for viral clearance, the importance of host antibodies in clearing HCV infection is being increasingly recognized. Indeed, recent studies indicate that neutralizing antibodies are induced in the early phase of infection by patients who subsequently clear viral infection. Conversely, patients who do not clear the virus develop high titers of neutralizing antibodies during the chronic stage. Surprisingly, these antibodies are not able to control HCV infection. HCV has therefore developed mechanisms to evade immune elimination, allowing it to persist in the majority of infected individuals. A detailed understanding of the mechanisms by which the virus escapes immune surveillance is therefore necessary if novel preventive and therapeutic treatments have to be designed. This review summarizes the current knowledge of the mechanisms used by HCV to evade host neutralizing antibodies.

  13. Hepatitis C virus evasion mechanisms from neutralizing antibodies.

    Science.gov (United States)

    Di Lorenzo, Caterina; Angus, Allan G N; Patel, Arvind H

    2011-11-01

    Hepatitis C virus (HCV) represents a major public health problem, affecting 3% of the world's population. The majority of infected individuals develop chronic hepatitis, which can progress to cirrhosis and hepatocellular carcinoma. To date, a vaccine is not available and current therapy is limited by resistance, adverse effects and high costs. Although it is very well established that cell-mediated immunity is necessary for viral clearance, the importance of host antibodies in clearing HCV infection is being increasingly recognized. Indeed, recent studies indicate that neutralizing antibodies are induced in the early phase of infection by patients who subsequently clear viral infection. Conversely, patients who do not clear the virus develop high titers of neutralizing antibodies during the chronic stage. Surprisingly, these antibodies are not able to control HCV infection. HCV has therefore developed mechanisms to evade immune elimination, allowing it to persist in the majority of infected individuals. A detailed understanding of the mechanisms by which the virus escapes immune surveillance is therefore necessary if novel preventive and therapeutic treatments have to be designed. This review summarizes the current knowledge of the mechanisms used by HCV to evade host neutralizing antibodies.

  14. The influence of Mars' magnetic topology on atmospheric escape

    Science.gov (United States)

    Curry, S.; Luhmann, J. G.; DiBraccio, G. A.; Dong, C.; Xu, S.; Mitchell, D.; Gruesbeck, J.; Espley, J. R.; Connerney, J. E. P.; McFadden, J. P.; Ma, Y. J.; Brain, D.

    2017-12-01

    At weakly magnetized planets such as Mars and Venus, the solar wind directly interacts with the upper atmosphere where ions can be picked up and swept away by the background convection electric field. These pick-up ions have a gyroradius on the planetary scale that is largely dominated by the interplanetary magnetic field (IMF). But at Mars, their trajectory is also influenced by the existence of remanent crustal magnetic fields, which are thought to create a shielding effect for escaping planetary ions when they are on the dayside. Consequently, the magnetic topology changes at Mars as magnetic reconnection occurs between the draped (IMF) and the crustal magnetic fields (closed). The resulting topology includes open field lines in the solar wind with one footprint attached to the planet. Using magnetohydrodynamic (MHD) and test particle simulations, we will explore the influence of the magnetic topology on ion escape. We will present escape rates for planetary ions for different crustal field positions during different IMF configurations, with +/-BY and +/-BZ components in the Mars Sun Orbit (MSO) coordinate system. We will also compare global maps of ion outflow and escape with open / closed magnetic field line maps and compare our results with ion fluxes and magnetic field data from the Mars Atmospheric and Volatile EvolutioN (MAVEN) mission. Our results relating the dynamic magnetic field topology at Mars and planetary ion escape are an important aspect of magnetospheric physics and planetary evolution, both of which have applications to our own solar system and the increasing number of exoplanets discovered every year.

  15. An Empirical Investigation of Time-Out with and without Escape Extinction to Treat Escape-Maintained Noncompliance

    Science.gov (United States)

    Everett, Gregory E.; Olmi, D. Joe; Edwards, Ron P.; Tingstrom, Daniel H.; Sterling-Turner, Heather E.; Christ, Theodore J.

    2007-01-01

    The present study evaluates the effectiveness of two time-out (TO) procedures in reducing escape-maintained noncompliance of 4 children. Noncompliant behavioral function was established via a functional assessment (FA), including indirect and direct descriptive procedures and brief confirmatory experimental analyses. Following FA, parents were…

  16. Maternal Neutralization-Resistant Virus Variants Do Not Predict Infant HIV Infection Risk.

    Science.gov (United States)

    Milligan, Caitlin; Omenda, Maxwel M; Chohan, Vrasha; Odem-Davis, Katherine; Richardson, Barbra A; Nduati, Ruth; Overbaugh, Julie

    2016-02-02

    neutralization escape variants. There are limited data demonstrating whether NAbs can prevent HIV transmission and infection in humans, and for this reason, NAbs have been studied in MTCT, where maternal antibodies are present at the time of transmission. Results of these studies have varied, perhaps because of differences in methods. Importantly, studies often used cultured viruses and samples from time points outside the window of transmission, which could confound findings. Here, we considered the role of maternal NAbs against individual maternal virus variants near the time of transmission. We found no evidence that NAbs are associated with protection from infection. In fact, depending on the cutoff used to define neutralization resistance, we found evidence that nontransmitting mothers have more neutralization-resistant virus variants. These results suggest that lack of virus transmission in the early breastfeeding period is not simply due to an absence of maternal neutralization escape variants and likely includes multiple factors. Copyright © 2016 Milligan et al.

  17. Universal Drive Train Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This vehicle drive train research facility is capable of evaluating helicopter and ground vehicle power transmission technologies in a system level environment. The...

  18. Control rod drives

    International Nuclear Information System (INIS)

    Kimura, Koichi.

    1994-01-01

    In control rod drives, differential pressure sensors are disposed at the inlet and the exit of a driving water pressure control valve disposed in a driving water supply device and, when deviation of fluctuation of the differential pressure from a set value is detected, a pressure control valve for driving water is controlled so as to make the differential pressure constant. The differential pressure sensors detect the differential pressure between the pressure of the control rod drives at the inlet and the exit of the driving water pressure control valve and a pressure in a reactor dome. A judging circuit judges whether the differential pressure between both sides of the driving water pressure control valve is deviated from a set value or not and, if it deviates from the set value, outputs of judging signal to the control device. In the control device, the opening degree of the driving water pressure control valve is controlled, so that the differential pressure between both sides of the driving water pressure control value is constant and does not deviate from the set value. There are provided advantageous effects of preventing abnormal control rod withdrawing phenomenon to improve safety and reliability for the control of the reactor operation. (N.H.)

  19. Medications and impaired driving.

    Science.gov (United States)

    Hetland, Amanda; Carr, David B

    2014-04-01

    To describe the association of specific medication classes with driving outcomes and provide clinical recommendations. The MEDLINE and EMBASE databases were searched for articles published from January 1973 to June 2013 on classes of medications associated with driving impairment. The search included outcome terms such as automobile driving, motor vehicle crash, driving simulator, and road tests. Only English-language articles that contained findings from observational or interventional designs with ≥ 10 participants were included in this review. Cross-sectional studies, case series, and case reports were excluded. Driving is an important task and activity for the majority of adults. Some commonly prescribed medications have been associated with driving impairment measured by road performance, driving simulation, and/or motor vehicle crashes. This review of 30 studies identified findings with barbiturates, benzodiazepines, hypnotics, antidepressants, opioid and nonsteroidal analgesics, anticonvulsants, antipsychotics, antiparkinsonian agents, skeletal muscle relaxants, antihistamines, anticholinergic medications, and hypoglycemic agents. Additional studies of medication impact on sedation, sleep latency, and psychomotor function, as well as the role of alcohol, are also discussed. Psychotropic agents and those with central nervous system side effects were associated with measures of impaired driving performance. It is difficult to determine if such associations are actually a result of medication use or the medical diagnosis itself. Regardless, clinicians should be aware of the increased risk of impaired driving with specific classes of medications, educate their patients, and/or consider safer alternatives.

  20. Neutrality Versus Materiality: A Thermodynamic Theory of Neutral Surfaces

    Directory of Open Access Journals (Sweden)

    Rémi Tailleux

    2016-09-01

    Full Text Available In this paper, a theory for constructing quasi-neutral density variables γ directly in thermodynamic space is formulated, which is based on minimising the absolute value of a purely thermodynamic quantity J n . Physically, J n has a dual dynamic/thermodynamic interpretation as the quantity controlling the energy cost of adiabatic and isohaline parcel exchanges on material surfaces, as well as the dependence of in-situ density on spiciness, in a description of water masses based on γ, spiciness and pressure. Mathematically, minimising | J n | in thermodynamic space is showed to be equivalent to maximising neutrality in physical space. The physics of epineutral dispersion is also reviewed and discussed. It is argued, in particular, that epineutral dispersion is best understood as the aggregate effect of many individual non-neutral stirring events (being understood here as adiabatic and isohaline events with non-zero buoyancy, so that it is only the net displacement aggregated over many events that is approximately neutral. This new view resolves an apparent paradox between the focus in neutral density theory on zero-buoyancy motions and the overwhelming evidence that lateral dispersion in the ocean is primarily caused by non-zero buoyancy processes such as tides, residual currents and sheared internal waves. The efficiency by which a physical process contributes to lateral dispersion can be characterised by its energy signature, with those processes releasing available potential energy (negative energy cost being more efficient than purely neutral processes with zero energy cost. The latter mechanism occurs in the wedge of instability, and its source of energy is the coupling between baroclinicity, thermobaricity, and density compensated temperature/salinity anomalies. Such a mechanism, which can only exist in a salty ocean, is speculated to be important for dissipating spiciness anomalies and neutral helicity. The paper also discusses potential

  1. Weak neutral-current interactions

    International Nuclear Information System (INIS)

    Barnett, R.M.

    1978-08-01

    The roles of each type of experiment in establishing uniquely the values of the the neutral-current couplings of u and d quarks are analyzed together with their implications for gauge models of the weak and electromagnetic interactions. An analysis of the neutral-current couplings of electrons and of the data based on the assumption that only one Z 0 boson exists is given. Also a model-independent analysis of parity violation experiments is discussed. 85 references

  2. Weak neutral-current interactions

    Energy Technology Data Exchange (ETDEWEB)

    Barnett, R.M.

    1978-08-01

    The roles of each type of experiment in establishing uniquely the values of the the neutral-current couplings of u and d quarks are analyzed together with their implications for gauge models of the weak and electromagnetic interactions. An analysis of the neutral-current couplings of electrons and of the data based on the assumption that only one Z/sup 0/ boson exists is given. Also a model-independent analysis of parity violation experiments is discussed. 85 references. (JFP)

  3. The Lyman Alpha Reference Sample. V. The Impact of Neutral ISM Kinematics and Geometry on Lyalpha Escape

    Czech Academy of Sciences Publication Activity Database

    Rivera-Thorsen, T.; Hayes, M.; Ostlin, G.; Duval, F.; Orlitová, Ivana; Verhamme, A.; Más-Hesse, J. M.; Schaerer, D.; Cannon, J.M.; Oti-Floranes, H.; Sandberg, A.; Guaita, L.; Adamo, A.; Atek, H.; Herenz, E.Ch.; Kunth, D.; Laursen, P.; Melinder, J.

    2015-01-01

    Roč. 805, č. 1 (2015), 14/1-14/26 ISSN 0004-637X R&D Projects: GA ČR(CZ) GP14-20666P Institutional support: RVO:67985815 Keywords : cosmology * observations * galaxies Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 5.909, year: 2015

  4. Novel rabies virus-neutralizing epitope recognized by human monoclonal antibody: Fine mapping and escape mutant analysis

    NARCIS (Netherlands)

    Marissen, W.E.; Kramer, R.A.; Rice, A.; Weldon, W.C.; Niezgoda, M.; Faber, M.; Slootstra, J.W.; Meloen, R.H.; Clijsters-van der Horst, M.; Visser, T.J.; Jongeneelen, M.; Thijsse, S.; Throsby, M.; Kruif, de J.; Rupprecht, C.E.; Dietzschold, B.; Goudsmit, J.; Bakker, A.B.H.

    2005-01-01

    Anti-rabies virus immunoglobulin combined with rabies vaccine protects humans from lethal rabies infections. For cost and safety reasons, replacement of the human or equine polyclonal immunoglobulin is advocated, and the use of rabies virus-specific monoclonal antibodies (MAbs) is recommended. We

  5. Novel rabies virus-neutralizing epitope recognized by human monoclonal antibody: fine mapping and escape mutant analysis

    NARCIS (Netherlands)

    Marissen, Wilfred E.; Kramer, R. Arjen; Rice, Amy; Weldon, William C.; Niezgoda, Michael; Faber, Milosz; Slootstra, Jerry W.; Meloen, Rob H.; Clijsters-van der Horst, Marieke; Visser, Therese J.; Jongeneelen, Mandy; Thijsse, Sandra; Throsby, Mark; de Kruif, John; Rupprecht, Charles E.; Dietzschold, Bernhard; Goudsmit, Jaap; Bakker, Alexander B. H.

    2005-01-01

    Anti-rabies virus immunoglobulin combined with rabies vaccine protects humans from lethal rabies infections. For cost and safety reasons, replacement of the human or equine polyclonal immunoglobulin is advocated, and the use of rabies virus-specific monoclonal antibodies (MAbs) is recommended. We

  6. The Neutral Gas and Ion Mass Spectrometer on the Mars Atmosphere and Volatile Evolution Mission

    Science.gov (United States)

    Mahaffy, Paul R.; Benna, Mehdi; King, Todd; Harpold, Daniel N.; Arvey, Robert; Barciniak, Michael; Bendt, Mirl; Carrigan, Daniel; Errigo, Therese; Holmes, Vincent; Johnson, Christopher S.; Kellogg, James; Kimvilakani, Patrick; Lefavor, Matthew; Hengemihle, Jerome; Jaeger, Ferzan; Lyness, Eric; Maurer, John; Melak, Anthony; Noreiga, Felix; Noriega, Marvin; Patel, Kiran; Prats, Benito; Raaen, Eric; Tan, Florence; Weidner, Edwin; Gundersen, Cynthia; Battel, Steven; Block, Bruce P.; Arnett, Ken; Miller, Ryan; Cooper, Curt; Edmonson, Charles; Nolan, J. Thomas

    2015-12-01

    The Neutral Gas and Ion Mass Spectrometer (NGIMS) of the Mars Atmosphere and Volatile Evolution Mission (MAVEN) is designed to measure the composition, structure, and variability of the upper atmosphere of Mars. The NGIMS complements two other instrument packages on the MAVEN spacecraft designed to characterize the neutral upper atmosphere and ionosphere of Mars and the solar wind input to this region of the atmosphere. The combined measurement set is designed to quantify atmosphere escape rates and provide input to models of the evolution of the martian atmosphere. The NGIMS is designed to measure both surface reactive and inert neutral species and ambient ions along the spacecraft track over the 125-500 km altitude region utilizing a dual ion source and a quadrupole analyzer.

  7. Turbulence simulation taking account of inhomogeneity of neutral density in linear devices

    Science.gov (United States)

    Kasuya, N.; Abe, S.; Sasaki, M.; Inagaki, S.; Kobayashi, T.; Yagi, M.

    2018-01-01

    It is important to consider a combination of inhomogeneities, which drive and/or damp instabilities in magnetized plasmas. The inhomogeneity of neutral particle density is taken into account for analyzing turbulent states in linear devices by combining two kinds of simulations in this research. One is a simulation for 2D profiles of neutral particles and the other is that for resistive drift wave turbulence. Radial and axial profiles of neutral particles are calculated by the Monte Carlo method with a configuration of linear device PANTA. The ratio for ionization of neutral particles depends on the electron temperature, and the higher temperature in the operation range makes the neutral density smaller near the center of the plasma. Then, the radial profile of the ion-neutral collision frequency is set by introducing these neutral density profiles into resistive drift wave turbulence simulations. Smaller ion-neutral collision frequency makes the instabilities more unstable, and its inhomogeneity enhances mean electrostatic potential formation. The eigenmode structure is changed with the inhomogeneous ion-neutral collision frequency, and convective derivative nonlinearity generates the azimuthal flow near the center of the plasma. Two roles of the neutral particles on the turbulence, the direct change in linear instabilities and formation of background flows, become clear.

  8. Confinement of pure electron plasmas in the Columbia Non-neutral Torus

    International Nuclear Information System (INIS)

    Berkery, John W.; Pedersen, Thomas Sunn; Kremer, Jason P.; Marksteiner, Quinn R.; Lefrancois, Remi G.; Hahn, Michael S.; Brenner, Paul W.

    2007-01-01

    The Columbia Non-neutral Torus (CNT) [T. S. Pedersen, J. P. Kremer, R. G. Lefrancois, Q. Marksteiner, N. Pomphrey, W. Reiersen, F. Dahlgreen, and X. Sarasola, Fusion Sci. Technol. 50, 372 (2006)] is a stellarator used to study non-neutral plasmas confined on magnetic surfaces. A detailed experimental study of confinement of pure electron plasmas in CNT is described here. Electrons are introduced into the magnetic surfaces by placing a biased thermionic emitter on the magnetic axis. As reported previously, the insulated rods holding this and other emitter filaments contribute to the radial transport by charging up negatively and creating ExB convective transport cells. A model for the rod-driven transport is presented and compared to the measured transport rates under a number of different conditions, finding good agreement. Neutrals also drive transport, and by varying the neutral pressure in the experiment, the effects of rod-driven and neutral-driven transport are separated. The neutral-driven electron loss rate scales linearly with neutral pressure. The neutral driven transport, presumably caused by electron-neutral collisions, is much greater than theoretical estimates for neoclassical diffusion in a classical stellarator with strong radial electric fields. In fact the confinement time is on the order of the electron-neutral collision time. Ion accumulation, electron attachment, and other effects are considered, but do not explain the observed transport rates

  9. Vendor neutral archive in PACS.

    Science.gov (United States)

    Agarwal, Tapesh Kumar; Sanjeev

    2012-10-01

    An archive is a location containing a collection of records, documents, or other materials of historical importance. An integral part of Picture Archiving and Communication System (PACS) is archiving. When a hospital needs to migrate a PACS vendor, the complete earlier data need to be migrated in the format of the newly procured PACS. It is both time and money consuming. To address this issue, the new concept of vendor neutral archive (VNA) has emerged. A VNA simply decouples the PACS and workstations at the archival layer. This is achieved by developing an application engine that receives, integrates, and transmits the data using the different syntax of a Digital Imaging and Communication in Medicine (DICOM) format. Transferring the data belonging to the old PACS to a new one is performed by a process called migration of data. In VNA, a number of different data migration techniques are available to facilitate transfer from the old PACS to the new one, the choice depending on the speed of migration and the importance of data. The techniques include simple DICOM migration, prefetch-based DICOM migration, medium migration, and the expensive non-DICOM migration. "Vendor neutral" may not be a suitable term, and "architecture neutral," "PACS neutral," "content neutral," or "third-party neutral" are probably better and preferred terms. Notwithstanding this, the VNA acronym has come to stay in both the medical IT user terminology and in vendor nomenclature, and radiologists need to be aware of its impact in PACS across the globe.

  10. Vendor neutral archive in PACS

    Directory of Open Access Journals (Sweden)

    Tapesh Kumar Agarwal

    2012-01-01

    Full Text Available An archive is a location containing a collection of records, documents, or other materials of historical importance. An integral part of Picture Archiving and Communication System (PACS is archiving. When a hospital needs to migrate a PACS vendor, the complete earlier data need to be migrated in the format of the newly procured PACS. It is both time and money consuming. To address this issue, the new concept of vendor neutral archive (VNA has emerged. A VNA simply decouples the PACS and workstations at the archival layer. This is achieved by developing an application engine that receives, integrates, and transmits the data using the different syntax of a Digital Imaging and Communication in Medicine (DICOM format. Transferring the data belonging to the old PACS to a new one is performed by a process called migration of data. In VNA, a number of different data migration techniques are available to facilitate transfer from the old PACS to the new one, the choice depending on the speed of migration and the importance of data. The techniques include simple DICOM migration, prefetch-based DICOM migration, medium migration, and the expensive non-DICOM migration. "Vendor neutral" may not be a suitable term, and "architecture neutral," "PACS neutral," "content neutral," or "third-party neutral" are probably better and preferred terms. Notwithstanding this, the VNA acronym has come to stay in both the medical IT user terminology and in vendor nomenclature, and radiologists need to be aware of its impact in PACS across the globe.

  11. ANALYTIC SOLUTION FOR SELF-REGULATED COLLECTIVE ESCAPE OF COSMIC RAYS FROM THEIR ACCELERATION SITES

    International Nuclear Information System (INIS)

    Malkov, M. A.; Diamond, P. H.; Sagdeev, R. Z.; Aharonian, F. A.; Moskalenko, I. V.

    2013-01-01

    Supernova remnants (SNRs), as the major contributors to the galactic cosmic rays (CRs), are believed to maintain an average CR spectrum by diffusive shock acceleration regardless of the way they release CRs into the interstellar medium (ISM). However, the interaction of the CRs with nearby gas clouds crucially depends on the release mechanism. We call into question two aspects of a popular paradigm of the CR injection into the ISM, according to which they passively and isotropically diffuse in the prescribed magnetic fluctuations as test particles. First, we treat the escaping CR and the Alfvén waves excited by them on an equal footing. Second, we adopt field-aligned CR escape outside the source, where the waves become weak. An exact analytic self-similar solution for a CR ''cloud'' released by a dimmed accelerator strongly deviates from the test-particle result. The normalized CR partial pressure may be approximated as P(p,z,t)=2[|z| 5/3 +z dif 5/3 (p,t)] -3/5 exp[-z 2 /4D ISM (p)t], where p is the momentum of CR particle, and z is directed along the field. The core of the cloud expands as z dif ∝√(D NL (p)t) and decays in time as p∝2z -1 dif (t). The diffusion coefficient D NL is strongly suppressed compared to its background ISM value D ISM : D NL ∼ D ISM exp (– Π) ISM for sufficiently high field-line-integrated CR partial pressure, Π. When Π >> 1, the CRs drive Alfvén waves efficiently enough to build a transport barrier (p≈2/∣z∣— p edestal ) that strongly reduces the leakage. The solution has a spectral break at p = p br , where p br satisfies the equation D NL (p br ) ≅ z 2 /t.

  12. Analytic Solution for Self-regulated Collective Escape of Cosmic Rays from Their Acceleration Sites

    Science.gov (United States)

    Malkov, M. A.; Diamond, P. H.; Sagdeev, R. Z.; Aharonian, F. A.; Moskalenko, I. V.

    2013-05-01

    Supernova remnants (SNRs), as the major contributors to the galactic cosmic rays (CRs), are believed to maintain an average CR spectrum by diffusive shock acceleration regardless of the way they release CRs into the interstellar medium (ISM). However, the interaction of the CRs with nearby gas clouds crucially depends on the release mechanism. We call into question two aspects of a popular paradigm of the CR injection into the ISM, according to which they passively and isotropically diffuse in the prescribed magnetic fluctuations as test particles. First, we treat the escaping CR and the Alfvén waves excited by them on an equal footing. Second, we adopt field-aligned CR escape outside the source, where the waves become weak. An exact analytic self-similar solution for a CR "cloud" released by a dimmed accelerator strongly deviates from the test-particle result. The normalized CR partial pressure may be approximated as {P}(p,z,t)=2[|z|^{5/3}+z_{dif}^{5/3}(p,t)]^{-3/5}\\exp [-z^{2}/4D_{ISM}(p)t], where p is the momentum of CR particle, and z is directed along the field. The core of the cloud expands as z_{dif}\\propto \\sqrt{D_{NL}\\left(p\\right)t} and decays in time as {P}\\propto 2z_{dif}^{-1}\\left(t\\right). The diffusion coefficient D NL is strongly suppressed compared to its background ISM value D ISM: D NL ~ D ISMexp (- Π) Lt D ISM for sufficiently high field-line-integrated CR partial pressure, Π. When Π Gt 1, the CRs drive Alfvén waves efficiently enough to build a transport barrier ( {P}\\approx 2/\\left|z\\right|—"pedestal") that strongly reduces the leakage. The solution has a spectral break at p = p br, where p br satisfies the equation D NL(p br) ~= z 2/t.

  13. Deformation-driven fluid escape in the Levant Basin, offshore southern Israel

    Science.gov (United States)

    Eruteya, Ovie Emmanuel; Waldmann, Nicolas; Reshef, Moshe; Ben-Avraham, Zvi

    2016-04-01

    Submarine fluid emissions are global phenomena, which can be inferred from the presence of seafloor morphologies (e.g. pockmarks, mud volcanoes) occurring in various geological settings. However, despite the Levant Basin been a prolific hydrocarbon province, only a paucity of fluid escape morphologies have been identified on the present-day seafloor. In this study, we present a detailed analysis of a newly available high-resolution 3D seismic reflection dataset from offshore southern Israel. Evidences of subsurface fluid plumbing and escape are manifested here as present-day seafloor pockmarks, paleo-pockmarks, pipe structures and enhanced reflectivity patterns. Interestingly, these pockmarks are situated on and around bathymetric highs, which are ridges related to the Palmachim Disturbance. Our initial results show the fluid flow structures are spatially localized above a region of complex evaporites evacuation at depth, and likewise proximal to a shallower region characterized by high amplitude reflectors. The latter may be evidences for a shallow gas system. Our initial hypothesis proposes a dual shallow-source driven focused fluid flow system. Yet, we favour a deeper Messinian plumbing system driving fluid flow across the overburden in the study area. Corroborating this are fault systems characterized near the pipes feeding the seafloor pockmarks and paleo-pockmark, detaching in the upper Messinian evaporite. We further suggest that a combined supra-salt deformation system arising from the evacuation of the Messinian evaporites coupled with gravitational tectonics are in charge of modulating focused fluid flow. Under this scenario the emplaced mass transport complex acts as a transient reservoir for fluid flow, dewatering under deformation and channelling fluids towards the seafloor for expulsion. However, the contributions from microbially-generated methane in the shallow Quaternary overburden associated with the channel-levee complex cannot be neglected.

  14. ESCAP holds training workshop to improve monitoring of reproductive health.

    Science.gov (United States)

    1998-01-01

    While governments in the ESCAP region have made significant efforts toward meeting the 1994 International Conference on Population and Development (ICPD) Program of Action recommendations to reorient and broaden reproductive health programs, obstacles related to the limited capacity of statistical systems for monitoring and evaluating progress in meeting ICPD goals have been problematic. With the goal of strengthening national capacities to monitor and evaluate comprehensive reproductive health programs, the Training Workshop on Improving the National Capacity for Monitoring Reproductive Health Programs was organized by ESCAP, with the financial support of the Netherlands. The workshop was held in Bangkok from November 23 to December 4, 1998, and attended by 15 participants from Cambodia, Laos, Mongolia, Myanmar, Nepal, Pakistan, and Vietnam. Participants were drawn from countries' ministries of health and national statistical agencies. Workshop participants valued the experience and look forward to receiving additional training in the field.

  15. Behavioral analysis of the escape response in larval zebrafish

    Science.gov (United States)

    Feng, Ruopei; Girdhar, Kiran; Chemla, Yann; Gruebele, Martin

    The behavior of larval zebrafish is of great interest because the limited number of locomotor neurons in larval zebrafish couples with its rich repertoire of movements as a vertebrate animal. Current research uses a priori-selected parameters to describe their swimming behavior while our lab has built a parameter-free model based on singular value decomposition analysis to characterize it. Our previous work has analyzed the free swimming of larval zebrafish and presented a different picture from the current classification of larval zebrafish locomotion. Now we are extending this work to the studies of their escape response to acoustic stimulus. Analysis has shown intrinsic difference in the locomotion between escape response and free swimming.

  16. Fixation and escape times in stochastic game learning

    International Nuclear Information System (INIS)

    Realpe-Gomez, John; Szczesny, Bartosz; Galla, Tobias; Dall’Asta, Luca

    2012-01-01

    Evolutionary dynamics in finite populations is known to fixate eventually in the absence of mutation. We here show that a similar phenomenon can be found in stochastic game dynamical batch learning, and investigate fixation in learning processes in a simple 2×2 game, for two-player games with cyclic interaction, and in the context of the best-shot network game. The analogues of finite populations in evolution are here finite batches of observations between strategy updates. We study when and how such fixation can occur, and present results on the average time-to-fixation from numerical simulations. Simple cases are also amenable to analytical approaches and we provide estimates of the behaviour of so-called escape times as a function of the batch size. The differences and similarities with escape and fixation in evolutionary dynamics are discussed. (paper)

  17. Fractionation of noble gases by thermal escape from accreting planetesimals

    International Nuclear Information System (INIS)

    Donahue, T.M.

    1986-01-01

    Assuming solar initial elemental and isotopic ratios and a determination of the degree of fractionation occurring by competition between gravitational binding and escape, a model is developed for selective noble gas loss through escape during the growth of planetesimals to form the terrestrial planets. Of the two classes of planetesimals that can form on a time scale that is consistent with modern accretion models, one is depleted in neon while the other is neon-rich. The mechanism is noted to be capable of accounting for all known properties of the noble gas volatiles on the terrestrial planets, with only one exception, namely the Ar-36/Ar-38 ratios for Mars and the earth, which are much lower than observed. 11 references

  18. Library Lockdown: An escape room by kids for the community

    Directory of Open Access Journals (Sweden)

    Jennifer Thoegersen

    2016-11-01

    Full Text Available In Brief Hoping to bring the unexpected to Nebraska City, the Morton-James Public Library applied for an ALA Association for Library Service to Children Curiosity Creates grant to undertake an ambitious project: build an escape room. In a library storage room. With children. The hope was  by trying something completely different, we could increase interest in the library throughout the community and build a sense of ownership in the participants, while encouraging creativity and having a lot of fun. Library Lockdown was a four-month program that brought several dozen kids together—age 8 to 13—to build a fully-functioning escape room. Their creation, the Lab of Dr. Morton McBrains, is now open for business.

  19. Escape of Mars atmospheric carbon through time by photochemical means

    Science.gov (United States)

    Luhmann, J. G.; Kim, J.; Nagy, A. F.

    1993-01-01

    Luhmann et al. recently suggested that sputtering of the Martian atmosphere by re-entering O(+) pickup ions could have provided a significant route of escape for CO2 and its products throughout Mars' history. They estimated that the equivalent of C in an approximately 140-mbar CO2 atmosphere should have been lost this way if the Sun and solar wind evolved according to available models. Another source of escaping C (and O) that is potentially important is the dissociative recombination of ionospheric CO(+) near the exobase. We have evaluated the loss rates due to this process for 'ancient' solar EUV radiation fluxes of 1, 3, and 6 times the present flux in order to calculate the possible cumulative loss over the last 3.5 Gyr.

  20. State may be liable for HIV exposure from inmate's escape.

    Science.gov (United States)

    1999-09-03

    The Louisiana Court of Appeal is reviewing a case on whether the Louisiana prison system is liable to a private citizen who was exposed to HIV as a consequence of an inmate escape. The case questions whether the Department of Public Safety and Corrections had a duty to inform the local prison, where the inmate was transferred to, about his HIV infection and propensity to escape. The department requested a summary judgment stating that no such duty existed. This motion was rejected by the trial court. Affidavits were presented that questioned the facts and circumstances of the case. The department's duty to the prisoner and jail are in dispute and the trial court's denial has been deemed proper.

  1. The Endocannabinoid System Differentially Regulates Escape Behavior in Mice

    Directory of Open Access Journals (Sweden)

    Andreas J. Genewsky

    2017-10-01

    Full Text Available Among the hardwired behaviors, fear or survival responses certainly belong to the most evolutionary conserved ones. However, higher animals possess the ability to adapt to certain environments (e.g., novel foraging grounds, and, therefore, those responses need to be plastic. Previous studies revealed a cell-type specific role of the endocannabinoid system in novelty fear, conditioned fear and active vs. passive avoidance in a shuttle box paradigm. In this study we aim to investigate, whether knocking-out the cannabinoid receptor type-1 (CB1 on cortical glutamatergic (Glu-CB1−/− or GABAergic (GABA-CB1−/− neurons differentially affects the level of behavioral inhibition, which could ultimately lead to differences in escape behavior. In this context, we developed a novel behavioral paradigm, the Moving Wall Box (MWB. Using the MWB task we could show that Glu-CB1−/− mice have higher levels of behavioral inhibition over the course of repeated testing. GABA-CB1−/− mice, in contrast, showed significantly lower levels of behavioral inhibition compared to wild-type controls and more escape behavior. These changes in behavioral inhibition and escape behavior cannot be explained by altered levels of arousal, as repeated startle measurements revealed general habituation irrespective of the line and genotype of the animals. Taken together, we could show that CB1 on cortical glutamatergic terminals is important for the acquisition of active avoidance, as the absence of CB1 on these neurons creates a bias toward inhibitory avoidance. This is the case in situations without punishment such as electric footshocks. On the contrary CB1 receptors on GABAergic neurons mediate the acquisition of passive avoidance, as the absence of CB1 on those neurons establishes a strong bias toward escape behavior.

  2. UNESCO to blame:Reality or easy escape?

    OpenAIRE

    Pereira Roders, A Ana; Grigolon, AB Anna

    2015-01-01

    “UNESCO to blame” is a trend often observed in scholarly works. In those studies UNESCO is accused to privilege Eurocentric standards on heritage conservation. Is this reality or an easy escape? Can this trend be noted in other UNESCO reference texts? This article seeks to answer this question by studying the two main inscription-based conventions and their contribution to heritage management, while performing a data analysis on the countries behind these conventions, and their roles over tim...

  3. The escape of natural satellites from Mercury and Venus

    International Nuclear Information System (INIS)

    Kumar, S.S.

    1977-01-01

    It is suggested that the slow rotations of Mercury and Venus may be connected with the absence of natural satellites around them. If Mercury or Venus possessed a satellite at the time of formation, the tidal evolution would have caused the satellite to recede. At a sufficiently large distance from the planet, the Sun's gravitational influence makes the satellite orbit unstable. The natural satellites of Mercury and Venus might have escaped as a consequence of this instability. (Auth.)

  4. Efficiencies of gas neutralizers for multi-MeV beams of light negative ions

    International Nuclear Information System (INIS)

    Grisham, L.R.; Post, D.E.; Johnson, B.M.; Jones, K.W.; Barrette, J.; Kruse, T.H.; Tserruya, I.; Da-Hai, W.

    1982-01-01

    We report measurements of the neutral and charged particle fractions produced by running beams of Li - , C - , O - , and Si - at energies up to 7 MeV through gas cells of N 2 , Ar, or CO 2 . We discuss the implications of these measurements for the design of neutralizers to produce high-energy light atom beams for heating or current drive in tokamaks

  5. Electric Vehicle - Economical driving

    DEFF Research Database (Denmark)

    Jensen, VCE, Steen V.; Schøn, Henriette

    1999-01-01

    How do you reduce the energy-wast when driving and loading EV's - or rather: How do I get more km/l out of an EV......How do you reduce the energy-wast when driving and loading EV's - or rather: How do I get more km/l out of an EV...

  6. Fundamentals of electrical drives

    CERN Document Server

    Veltman, André; De Doncker, Rik W

    2007-01-01

    Provides a comprehensive introduction to various aspects of electrical drive systems. This volume provides a presentation of dynamic generic models that cover all major electrical machine types and modulation/control components of a drive as well as dynamic and steady state analysis of transformers and electrical machines.

  7. Piezoelectric drive circuit

    Science.gov (United States)

    Treu, C.A. Jr.

    1999-08-31

    A piezoelectric motor drive circuit is provided which utilizes the piezoelectric elements as oscillators and a Meacham half-bridge approach to develop feedback from the motor ground circuit to produce a signal to drive amplifiers to power the motor. The circuit automatically compensates for shifts in harmonic frequency of the piezoelectric elements due to pressure and temperature changes. 7 figs.

  8. Switched reluctance motor drives

    Indian Academy of Sciences (India)

    Davis RM, Ray WF, Blake RJ 1981 Inverter drive for switched reluctance: circuits and component ratings. Inst. Elec. Eng. Proc. B128: 126-136. Ehsani M. 1991 Position Sensor elimination technique for the switched reluctance motor drive. US Patent No. 5,072,166. Ehsani M, Ramani K R 1993 Direct control strategies based ...

  9. Self-driving carsickness.

    NARCIS (Netherlands)

    Diels, C.; Bos, J.E.

    2016-01-01

    This paper discusses the predicted increase in the occurrence and severity of motion sickness in self-driving cars. Self-driving cars have the potential to lead to significant benefits. From the driver's perspective, the direct benefits of this technology are considered increased comfort and

  10. Self-driving carsickness

    NARCIS (Netherlands)

    Diels, C.; Bos, J.E.

    2016-01-01

    This paper discusses the predicted increase in the occurrence and severity of motion sickness in self-driving cars. Self-driving cars have the potential to lead to significant benefits. From the driver's perspective, the direct benefits of this technology are considered increased comfort and

  11. Predictions of fast wave heating, current drive, and current drive antenna arrays for advanced tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Batchelor, D.B.; Baity, F.W.; Carter, M.D. [and others

    1994-12-31

    The objective of the advanced tokamak program is to optimize plasma performance leading to a compact tokamak reactor through active, steady state control of the current profile using non-inductive current drive and profile control. To achieve these objectives requires compatibility and flexibility in the use of available heating and current drive systems--ion cyclotron radio frequency (ICRF), neutral beams, and lower hybrid. For any advanced tokamak, the following are important challenges to effective use of fast waves in various roles of direct electron heating, minority ion heating, and current drive: (1) to employ the heating and current drive systems to give self-consistent pressure and current profiles leading to the desired advanced tokamak operating modes; (2) to minimize absorption of the fast waves by parasitic resonances, which limit current drive; (3) to optimize and control the spectrum of fast waves launched by the antenna array for the required mix of simultaneous heating and current drive. The authors have addressed these issues using theoretical and computational tools developed at a number of institutions by benchmarking the computations against available experimental data and applying them to the specific case of TPX.

  12. Predictions of fast wave heating, current drive, and current drive antenna arrays for advanced tokamaks

    International Nuclear Information System (INIS)

    Batchelor, D.B.; Baity, F.W.; Carter, M.D.

    1994-01-01

    The objective of the advanced tokamak program is to optimize plasma performance leading to a compact tokamak reactor through active, steady state control of the current profile using non-inductive current drive and profile control. To achieve these objectives requires compatibility and flexibility in the use of available heating and current drive systems--ion cyclotron radio frequency (ICRF), neutral beams, and lower hybrid. For any advanced tokamak, the following are important challenges to effective use of fast waves in various roles of direct electron heating, minority ion heating, and current drive: (1) to employ the heating and current drive systems to give self-consistent pressure and current profiles leading to the desired advanced tokamak operating modes; (2) to minimize absorption of the fast waves by parasitic resonances, which limit current drive; (3) to optimize and control the spectrum of fast waves launched by the antenna array for the required mix of simultaneous heating and current drive. The authors have addressed these issues using theoretical and computational tools developed at a number of institutions by benchmarking the computations against available experimental data and applying them to the specific case of TPX

  13. Oxygen and carbogen breathing following simulated submarine escape.

    Science.gov (United States)

    Gennser, Mikael; Loveman, Geoff; Seddon, Fiona; Thacker, Julian; Blogg, S Lesley

    2014-01-01

    Escape from a disabled submarine exposes escapers to a high risk of decompression sickness (DCS). The initial bubble load is thought to emanate from the fast tissues; it is this load that should be lowered to reduce risk of serious neurological DCS. The breathing of oxygen or carbogen (5% CO2, 95% O2) post-surfacing was investigated with regard to its ability to reduce the initial bubble load in comparison to air breathing. Thirty-two goats were subject to a dry simulated submarine escape profile to and from 240 meters (2.5 MPa). On surfacing, they breathed air (control), oxygen or carbogen for 30 minutes. Regular Doppler audio bubble grading was carried out, using the Kisman Masurel (KM) scale. One suspected case of DCS was noted. No oxygen toxicity or arterial gas embolism occurred. No significant difference was found between the groups in terms of the median peak KM grade or the period before the KM grade dropped below III. Time to disappearance of bubbles was significantly different between groups; oxygen showed faster bubble resolution than carbogen and air. This reduction in time to bubble resolution may be beneficial in reducing decompression stress, but probably does not affect the risk of fast-tissue DCS.

  14. Effective climate-energy solutions, escape routes and peak oil

    International Nuclear Information System (INIS)

    Bergh, Jeroen C.J.M. van den

    2012-01-01

    Many well-intended climate-energy strategies are ineffective in the absence of serious environmental regulation. This holds, among others, for direct support of clean energy, voluntary energy conservation, technical standards on a limited set of products, unilateral stringent carbon pricing, and awaiting peak oil as a climate strategy. All of these suffer from “escape routes” that indirectly increase CO 2 emissions and thus make the original strategy ineffective. On the other hand, environmental regulation alone may lead to a myopia-bias, stimulating early dominance of cost-effective technologies and a focus on incremental innovations associated with such technologies rather than on radical innovations. Although adopting a partial viewpoint keeps the analysis simple, we urgently need a more inclusive systems perspective on climate solutions. This will allow the formulation of an effective climate policy package that addresses the various escape routes. - Highlights: ► Many well-intended climate-energy strategies are ineffective because of escape routes. ► In this context the relationship between peak oil and climate policy receives attention. ► Environmental regulation alone creates myopia-bias, the resolution of which requires technology-specific policies. ► To formulate an effective climate policy package an inclusive systems perspective is needed.

  15. Transitions between three swimming gaits in Paramecium escape.

    Science.gov (United States)

    Hamel, Amandine; Fisch, Cathy; Combettes, Laurent; Dupuis-Williams, Pascale; Baroud, Charles N

    2011-05-03

    Paramecium and other protists are able to swim at velocities reaching several times their body size per second by beating their cilia in an organized fashion. The cilia beat in an asymmetric stroke, which breaks the time reversal symmetry of small scale flows. Here we show that Paramecium uses three different swimming gaits to escape from an aggression, applied in the form of a focused laser heating. For a weak aggression, normal swimming is sufficient and produces a steady swimming velocity. As the heating amplitude is increased, a higher acceleration and faster swimming are achieved through synchronized beating of the cilia, which begin by producing oscillating swimming velocities and later give way to the usual gait. Finally, escape from a life-threatening aggression is achieved by a "jumping" gait, which does not rely on the cilia but is achieved through the explosive release of a group of trichocysts in the direction of the hot spot. Measurements through high-speed video explain the role of trichocysts in defending against aggressions while showing unexpected transitions in the swimming of microorganisms. These measurements also demonstrate that Paramecium optimizes its escape pattern by taking advantage of its inertia.

  16. Control rod drives

    International Nuclear Information System (INIS)

    Nakamura, Akira.

    1984-01-01

    Purpose: To enable to monitor the coupling state between a control rod and a control rod drive. Constitution: After the completion of a control rod withdrawal, a coolant pressure is applied to a control rod drive being adjusted so as to raise only the control rod drive and, in a case where the coupling between the control rod drive and the control rod is detached, the former is elevated till it contacts the control rod and then stopped. The actual stopping position is detected by an actual position detection circuit and compared with a predetermined position stored in a predetermined position detection circuit. If both of the positions are not aligned with each other, it is judged by a judging circuit that the control rod and the control rod drives are not combined. (Sekiya, K.)

  17. Design of Neutral-Point Voltage Controller of a Three-level NPC Inverter with Small DC-Link Capacitors

    DEFF Research Database (Denmark)

    Maheshwari, Ram Krishan; Munk-Nielsen, Stig; Busquets-Monge, S.

    2013-01-01

    . This continuous model shows that the neutral-point current is proportional to the power drawn from the inverter, and it enables the use of well established classical control theory for the neutral-point voltage controller design. A simple PI (proportional integral) controller is designed for the neutral......-point voltage control on the basis of the continuous model. The design method for optimum performance is discussed. The implementation of the proposed modulation strategy and the controller is very simple. The controller is implemented in a 7.5 kW induction machine based drive with only 14 ìF dc-link capacitors......A Neutral-Point-Clamped (NPC) three-level inverter with small dc-link capacitors is presented in this paper. The inverter requires zero average neutral-point current for stable neutral-point voltage. The small dc-link capacitors may not maintain capacitor voltage balance, even with zero neutral...

  18. Electromagnetic trapping of neutral atoms

    International Nuclear Information System (INIS)

    Metcalf, H.J.

    1986-01-01

    Cooling and trapping of neutral atoms is a new branch of applied physics that has potential for application in many areas. The authors present an introduction to laser cooling and magnetic trapping. Some basic ideas and fundamental limitations are discussed, and the first successful experiments are reviewed. Trapping a neutral object depends on the interaction between an inhomogeneous electromagnetic field and a multiple moment that results in the exchange of kinetic for potential energy. In neutral atom traps, the potential energy must be stored as internal atomic energy, resulting in two immediate and extremely important consequences. First, the atomic energy levels will necessarily shift as the atoms move in the trap, and, second, practical traps for ground state neutral atoms atr necessarily very shallow compared to thermal energy. This small depth also dictates stringent vacuum requirements because a trapped atom cannot survive a single collision with a thermal energy background gas molecule. Neutral trapping, therefore, depends on substantial cooling of a thermal atomic sample and is inextricably connected with the cooling process

  19. Neutral ISM, Lyα, and Lyman-continuum in the Nearby Starburst Haro11

    Science.gov (United States)

    Rivera-Thorsen, T. Emil; Östlin, Göran; Hayes, Matthew; Puschnig, Johannes

    2017-03-01

    Star-forming galaxies are believed to be a major source of Lyman continuum (LyC) radiation responsible for reionizing the early universe. Direct observations of escaping ionizing radiation have however been sparse and with low escape fractions. In the local universe, only 10 emitters have been observed, with typical escape fractions of a few percent. The mechanisms regulating this escape need to be strongly evolving with redshift in order to account for the epoch of reionization. Gas content and star formation feedback are among the main suspects, known to both regulate neutral gas coverage and evolve with cosmic time. In this paper, we reanalyze Hubble Space Telescope (HST)-Cosmic Origins Spectrograph (COS) spectrocopy of the first detected local LyC leaker, Haro 11. We examine the connection between LyC leakage and Lyα line shape, and feedback-influenced neutral interstellar medium (ISM) properties like kinematics and gas distribution. We discuss the two extremes of an optically thin, density bounded ISM and a riddled, optically thick, ionization bounded ISM, and how Haro 11 fits into theoretical predictions. We find that the most likely ISM model is a clumpy neutral medium embedded in a highly ionized medium with a combined covering fraction of unity and a residual neutral gas column density in the ionized medium high enough to be optically thick to Lyα, but low enough to be at least partly transparent to LyC and undetected in Si II. This suggests that star formation feedback and galaxy-scale interaction events play a major role in opening passageways for ionizing radiation through the neutral medium. Based on observations with HST-COS, program GO 13017, obtained from the Mikulski Archive for Space Telescopes (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Support for MAST for non-HST data is provided by the NASA Office of Space Science via grant NNX09AF08G and by other grants and

  20. Turbulent current drive mechanisms

    Science.gov (United States)

    McDevitt, Christopher J.; Tang, Xian-Zhu; Guo, Zehua

    2017-08-01

    Mechanisms through which plasma microturbulence can drive a mean electron plasma current are derived. The efficiency through which these turbulent contributions can drive deviations from neoclassical predictions of the electron current profile is computed by employing a linearized Coulomb collision operator. It is found that a non-diffusive contribution to the electron momentum flux as well as an anomalous electron-ion momentum exchange term provide the most efficient means through which turbulence can modify the mean electron current for the cases considered. Such turbulent contributions appear as an effective EMF within Ohm's law and hence provide an ideal means for driving deviations from neoclassical predictions.

  1. Identifying Method of Drunk Driving Based on Driving Behavior

    Directory of Open Access Journals (Sweden)

    Xiaohua Zhao

    2011-05-01

    Full Text Available Drunk driving is one of the leading causes contributing to traffic crashes. There are numerous issues that need to be resolved with the current method of identifying drunk driving. Driving behavior, with the characteristic of real-time, was extensively researched to identify impaired driving behaviors. In this paper, the drives with BACs above 0.05% were defined as drunk driving state. A detailed comparison was made between normal driving and drunk driving. The experiment in driving simulator was designed to collect the driving performance data of the groups. According to the characteristics analysis for the effect of alcohol on driving performance, seven significant indicators were extracted and the drunk driving was identified by the Fisher Discriminant Method. The discriminant function demonstrated a high accuracy of classification. The optimal critical score to differentiate normal from drinking state was found to be 0. The evaluation result verifies the accuracy of classification method.

  2. Neutral B meson flavor tagging

    CERN Document Server

    Wilson, R J

    2001-01-01

    We present an investigation of the use of net charge and kaon identification to tag the flavor of neutral B mesons. The net charge of the neutral B meson decay products is zero if all charged particles are used and slightly non-zero if only undiscriminated hadronic final states are used. The net charge of the kaons alone correctly tags the identity of the neutral meson in at least a third of all decays. We have parametrized the particle identification capability of several techniques, such as dE/dx in time projection chambers, LEP/SLC ring-imaging chambers and an enhanced BaBar DIRC. Using these parametrisations we compare the relative tagging power of each technique to that of an ideal detector. (8 refs).

  3. Diversity of the Lyman continuum escape fractions of high-z galaxies and its origins

    Science.gov (United States)

    Sumida, Takumi; Kashino, Daichi; Hasegawa, Kenji

    2018-04-01

    The Lyman continuum (LyC) escape fraction is a key quantity to determine the contribution of galaxies to cosmic reionization. It has been known that the escape fractions estimated by observations and numerical simulations show a large diversity. However, the origins of the diversity are still uncertain. In this work, to understand what quantities of galaxies are responsible for controlling the escape fraction, we numerically evaluate the escape fraction by performing ray-tracing calculation with simplified disc galaxy models. With a smooth disc model, we explore the dependence of the escape fraction on the disposition of ionizing sources and find that the escape fraction varies up to ˜3 orders of magnitude. It is also found that the halo mass dependence of disc scale height determines whether the escape fraction increases or decreases with halo mass. With a clumpy disc model, it turns out that the escape fraction increases as the clump mass fraction increases because the density in the inter-clump region decreases. In addition, we find that clumpiness regulates the escape fraction via two ways when the total clump mass dominates the total gas mass; the escape fraction is controlled by the covering factor of clumps if the clumps are dense sufficient to block LyC photons, otherwise the clumpiness works to reduce the escape fraction by increasing the total number of recombination events in a galaxy.

  4. Emergence of Ebola Virus Escape Variants in Infected Nonhuman Primates Treated with the MB-003 Antibody Cocktail

    Directory of Open Access Journals (Sweden)

    Jeffrey R. Kugelman

    2015-09-01

    Full Text Available MB-003, a plant-derived monoclonal antibody cocktail used effectively in treatment of Ebola virus infection in non-human primates, was unable to protect two of six animals when initiated 1 or 2 days post-infection. We characterized a mechanism of viral escape in one of the animals, after observation of two clusters of genomic mutations that resulted in five nonsynonymous mutations in the monoclonal antibody target sites. These mutations were linked to a reduction in antibody binding and later confirmed to be present in a viral isolate that was not neutralized in vitro. Retrospective evaluation of a second independent study allowed the identification of a similar case. Four SNPs in previously identified positions were found in this second fatality, suggesting that genetic drift could be a potential cause for treatment failure. These findings highlight the importance selecting different target domains for each component of the cocktail to minimize the potential for viral escape.

  5. Neutral currents in semileptonic reactions

    International Nuclear Information System (INIS)

    Paschos, E.A.

    1975-05-01

    The evidence for weak neutral currents is analyzed in semileptonic reactions with special emphasis on their Lorentz and internal symmetry structure. It is found that present observations are consistent with the expectations of gauge theories, but other possibilities can not be ruled out. Of particular interest in this respect is the presence of a large isoscalar component. The excitation of the Δ-resonance by neutral currents is analyzed, and pion-nucleon mass distributions are presented. Charge asymmetries sensitive to isoscalar-isovector interferences are discussed. (U.S.)

  6. Linear step drive

    International Nuclear Information System (INIS)

    Haniger, L.; Elger, R.; Kocandrle, L.; Zdebor, J.

    1986-01-01

    A linear step drive is described developed in Czechoslovak-Soviet cooperation and intended for driving WWER-1000 control rods. The functional principle is explained of the motor and the mechanical and electrical parts of the drive, power control, and the indicator of position are described. The motor has latches situated in the reactor at a distance of 3 m from magnetic armatures, it has a low structural height above the reactor cover, which suggests its suitability for seismic localities. Its magnetic circuits use counterpoles; the mechanical shocks at the completion of each step are damped using special design features. The position indicator is of a special design and evaluates motor position within ±1% of total travel. A drive diagram and the flow chart of both the control electronics and the position indicator are presented. (author) 4 figs

  7. Drugs and driving

    NARCIS (Netherlands)

    Walsh, J. Michael; De Gier, Johan J.; Christopherson, Asbjørg S.; Verstraete, Alain G.

    The authors present a global overview on the issue of drugs and driving covering four major areas: (1) Epidemiology and Prevalence-which reviews epidemiological research, summarizes available information, discusses the methodological shortcomings of extant studies, and makes recommendations for

  8. Science of driving.

    Science.gov (United States)

    2016-08-01

    The Science of Driving project focused on developing a collaborative relationship to develop curriculum units for middle school and high school students to engage them in exciting real-world scenarios. This effort involved faculty, staff, and student...

  9. CONTROL ROD DRIVE

    Science.gov (United States)

    Chapellier, R.A.

    1960-05-24

    BS>A drive mechanism was invented for the control rod of a nuclear reactor. Power is provided by an electric motor and an outside source of fluid pressure is utilized in conjunction with the fluid pressure within the reactor to balance the loadings on the motor. The force exerted on the drive mechanism in the direction of scramming the rod is derived from the reactor fluid pressure so that failure of the outside pressure source will cause prompt scramming of the rod.

  10. Instant Google Drive starter

    CERN Document Server

    Procopio, Mike

    2013-01-01

    This book is a Starter which teaches you how to use Google Drive practically. This book is perfect for people of all skill levels who want to enjoy the benefits of using Google Drive to safely store their files online and in the cloud. It's also great for anyone looking to learn more about cloud computing in general. Readers are expected to have an Internet connection and basic knowledge of using the internet.

  11. Belt drive construction improvement

    Directory of Open Access Journals (Sweden)

    I.Yu. Khomenko

    2012-08-01

    Full Text Available The possibility of the traction capacity increase of the belt drive TRK is examined. This was done for the purpose of air conditioning system of passenger car with double-generator system energy supplying. Belts XPC (made by the German firm «Continental ContiTech» testing were conducted. The results confirmed the possibility of their usage in order to improve belt drive TRK characteristics.

  12. Epilepsy and driving

    Directory of Open Access Journals (Sweden)

    Moetamedi M

    2000-09-01

    Full Text Available Epilepsy is a disease with high prevalence, which interferes driving and may lead to car accident; This case-control study has been done on 100 epileptic patients and 100 persons as control group, who had history of driving. We gathered our patients with face to face interview and registering their information in special forms which were prepared for this study. There were three times more accidents among epileptic cases comparing with control group and this difference was more considerable in men and in patients under 35 years old. The cause of accident were not seizure attack in more than 60% of the patients and these ordinary accidents were also more in case group. Epileptic patients with history of car accidents during driving had poor drug compliance comparing with the epileptics without history of an accident so drug compliance may be valuable in predicting accident in these patients. We have also found poor drug compliance in whom seizure attacks caused accident for them. 58% of the epileptics had not consulted their physician about driving. 43.3% of seizures during driving were of generalized type and none of the patients had inform police about their disease during getting driving license.

  13. Dementia and driving.

    Science.gov (United States)

    O'Neill, D; Neubauer, K; Boyle, M; Gerrard, J; Surmon, D; Wilcock, G K

    1992-04-01

    Many European countries test cars, but not their drivers, as they age. There is evidence to suggest that human factors are more important than vehicular factors as causes of motor crashes. The elderly also are involved in more accidents per distance travelled than middle-aged drivers. As the UK relies on self-certification of health by drivers over the age of 70 years, we examined the driving practices of patients with dementia attending a Memory Clinic. Nearly one-fifth of 329 patients with documented dementia continued to drive after the onset of dementia, and impaired driving ability was noted in two-thirds of these. Their families experienced great difficulty in persuading patients to stop driving, and had to invoke outside help in many cases. Neuropsychological tests did not help to identify those who drove badly while activity of daily living scores were related to driving ability. These findings suggest that many patients with dementia drive in an unsafe fashion after the onset of the illness. The present system of self-certification of health by the elderly for driver-licensing purposes needs to be reassessed.

  14. Self-driving carsickness.

    Science.gov (United States)

    Diels, Cyriel; Bos, Jelte E

    2016-03-01

    This paper discusses the predicted increase in the occurrence and severity of motion sickness in self-driving cars. Self-driving cars have the potential to lead to significant benefits. From the driver's perspective, the direct benefits of this technology are considered increased comfort and productivity. However, we here show that the envisaged scenarios all lead to an increased risk of motion sickness. As such, the benefits this technology is assumed to bring may not be capitalised on, in particular by those already susceptible to motion sickness. This can negatively affect user acceptance and uptake and, in turn, limit the potential socioeconomic benefits that this emerging technology may provide. Following a discussion on the causes of motion sickness in the context of self-driving cars, we present guidelines to steer the design and development of automated vehicle technologies. The aim is to limit or avoid the impact of motion sickness and ultimately promote the uptake of self-driving cars. Attention is also given to less well known consequences of motion sickness, in particular negative aftereffects such as postural instability, and detrimental effects on task performance and how this may impact the use and design of self-driving cars. We conclude that basic perceptual mechanisms need to be considered in the design process whereby self-driving cars cannot simply be thought of as living rooms, offices, or entertainment venues on wheels. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  15. Escaping the Self: Identity, Group Identification and Violence

    Directory of Open Access Journals (Sweden)

    James Hardie-Bick

    2016-12-01

    Full Text Available This article draws on the early work of Erich Fromm. In Escape from Freedom Fromm (1969 [1941] directly addressed the psychological mechanisms of escape modern individuals employ to protect themselves from feelings of ontological insecurity and existential estrangement. The article builds on Fromm’s analysis by discussing the significance of his escape mechanisms for understanding the dynamic psychological attractions of identifying with entitative groups. Fromm’s work will be discussed in relation to Hogg’s recent work on uncertainty-identity theory. The aim of the article is to examine the advantages of combining Fromm’s psychoanalytic analysis with Hogg’s uncertainty-identity theory and to highlight the potential this approach has for understanding why groups engage in violent and destructive behaviour. Este artículo se inspira en las primeras obras de Erich Fromm. En El miedo a la libertad, Fromm (1969 [1941] abordó directamente los mecanismos psicológicos de evasión que los individuos modernos emplean para protegerse de los sentimientos de inseguridad ontológica y distanciamiento existencial. Este artículo se basa en el análisis de Fromm exponiendo el significado de sus mecanismos de evasión para entender las atracciones psicológicas dinámicas de identificación con grupos entitativos. Se analizará la obra de Fromm en relación con la obra reciente de Hogg sobre la teoría de incertidumbre identitaria. El objetivo del artículo es examinar las ventajas de combinar el análisis psicoanalítico de Fromm con la teoría de incertidumbre identitaria de Hogg, y destacar el potencial que tiene esta aproximación para comprender por qué los grupos adoptan un comportamiento violento y destructivo. DOWNLOAD THIS PAPER FROM SSRN: https://ssrn.com/abstract=2875737

  16. Chases and escapes the mathematics of pursuit and evasion

    CERN Document Server

    Nahin, Paul J

    2012-01-01

    We all played tag when we were kids. What most of us don't realize is that this simple chase game is in fact an application of pursuit theory, and that the same principles of games like tag, dodgeball, and hide-and-seek are also at play in military strategy, high-seas chases by the Coast Guard, and even romantic pursuits. In Chases and Escapes, Paul Nahin gives us the first complete history of this fascinating area of mathematics, from its classical analytical beginnings to the present day. Drawing on game theory, geometry, linear algebra, target-tracking algorithms, and much

  17. Mechanisms of Pulmonary Escape and Dissemination by Cryptococcus neoformans

    Directory of Open Access Journals (Sweden)

    Steven T. Denham

    2018-02-01

    Full Text Available Cryptococcus neoformans is a common environmental saprophyte and human fungal pathogen that primarily causes disease in immunocompromised individuals. Similar to many environmentally acquired human fungal pathogens, C. neoformans initiates infection in the lungs. However, the main driver of mortality is invasive cryptococcosis leading to fungal meningitis. After C. neoformans gains a foothold in the lungs, a critical early step in invasion is transversal of the respiratory epithelium. In this review, we summarize current knowledge relating to pulmonary escape. We focus on fungal factors that allow C. neoformans to disseminate from the lungs via intracellular and extracellular routes.

  18. Diffusion escape through a cluster of small absorbing windows

    Energy Technology Data Exchange (ETDEWEB)

    Holcman, D [Department of Mathematics, Weizmann Institute of Science, Rehovot 76100 (Israel); Schuss, Z [Department of Mathematics, Tel-Aviv University, Tel-Aviv 69978 (Israel)

    2008-04-18

    We study the first eigenvalue of the Laplace equation in a bounded domain in R{sup d} (d=2,3) with mixed Neumann-Dirichlet (Zaremba) boundary conditions. The Neumann condition is imposed on most of the boundary and the Dirichlet boundary consists of a cluster of small windows. When the windows are well separated the first eigenvalue is asymptotically the sum of eigenvalues of mixed problems with a single Dirichlet window. However, when two or more Dirichlet windows cluster tightly together they interact nonlinearly. We compare our asymptotic approximation of the eigenvalue to the escape rate of simulated Brownian particles through the small windows.

  19. Dynamics of Periodic Impulsive Collision in Escapement Mechanism

    Directory of Open Access Journals (Sweden)

    Jian Mao

    2013-01-01

    Full Text Available Among various non-smooth dynamic systems, the periodically forced oscillation system with impact is perhaps the most common in engineering applications. The dynamical study becomes complicated due to the impact. This paper presents a systematic study on the periodically forced oscillation system with impact. A simplified model of the escapement mechanism is introduced. Impulsive differential equation and Poincare map are applied to describe the model and study the stability of the system. Numerical examples are given and the results show that the model is highly accurate in describing/predicting their dynamics.

  20. The mirror of the escaped God – Alejandra Pizarnik

    Directory of Open Access Journals (Sweden)

    Mariano Carou

    2015-04-01

    Full Text Available Alejandra Pizarnik (1936-1972 shows many different stands regarding to “God’s escape” in her poetry and his diaries: from the psalmist’s request to the more combative atheism. There is, however, a constant development of a symbolic constellation to speak about God’s mistery, and the certitude –inherited from German romanticism– that the poet has always something to say about God’s escape, searching for a new hope in which is maybe a new form of mysticism.

  1. The mirror of the escaped God – Alejandra Pizarnik

    OpenAIRE

    Carou, Mariano

    2015-01-01

    Alejandra Pizarnik (1936-1972) shows many different stands regarding to “God’s escape” in her poetry and his diaries: from the psalmist’s request to the more combative atheism. There is, however, a constant development of a symbolic constellation to speak about God’s mistery, and the certitude –inherited from German romanticism– that the poet has always something to say about God’s escape, searching for a new hope in which is maybe a new form of mysticism. Alejandra Pizarnik (1936-1972) mu...

  2. The mirror of the escaped God – Alejandra Pizarnik

    OpenAIRE

    Mariano Carou

    2015-01-01

    Alejandra Pizarnik (1936-1972) shows many different stands regarding to “God’s escape” in her poetry and his diaries: from the psalmist’s request to the more combative atheism. There is, however, a constant development of a symbolic constellation to speak about God’s mistery, and the certitude –inherited from German romanticism– that the poet has always something to say about God’s escape, searching for a new hope in which is maybe a new form of mysticism.

  3. Test of time: what if little Albert had escaped?

    Science.gov (United States)

    Field, Andy P; Nightingale, Zoë C

    2009-04-01

    Watson and Rayner's (1920) ;Little Albert' experiment has become one of the most famous studies in psychology. It is a staple of many general psychology textbooks and is part of the very fabric of the discipline's folklore. Despite this fame, the study has been widely criticized in the nearly 90 years since it was published for its lack of methodological rigour. This article attempts to evaluate the contribution of the ;little Albert' study to modern clinical psychology by speculating on what theories and treatments of child anxiety would look like in a parallel universe in which the study never took place because ;little Albert' escaped from the hospital in which Watson tested him.

  4. International Environmental Agreements: Emissions Trade, Safety Valves and Escape Clauses

    International Nuclear Information System (INIS)

    Karp, Larry; Zhao, Jinhua

    2010-01-01

    We explain how the structure of multi-national or multi-regional environmental agreements affect their chance of success. Trade in emissions permits has ambiguous and in some cases surprising effects on both the equilibrium level of abatement, and on the ability to persuade nations or regions to participate in environmental agreements. An escape clause policy and a safety valve policy have essentially the same properties when membership in environmental agreement is pre-determined, but they create markedly different effects on the incentives to join such an agreement. The two policies lead to a qualitative difference in the leverage that a potential member of the agreement exercises on other members

  5. The edge of neutral evolution in social dilemmas

    International Nuclear Information System (INIS)

    Cremer, Jonas; Frey, Erwin; Reichenbach, Tobias

    2009-01-01

    The functioning of animal as well as human societies fundamentally relies on cooperation. Yet, defection is often favorable for the selfish individual, and social dilemmas arise. Selection by individuals' fitness, usually the basic driving force of evolution, quickly eliminates cooperators. However, evolution is also governed by fluctuations that can be of greater importance than fitness differences, and can render evolution effectively neutral. Here, we investigate the effects of selection versus fluctuations in social dilemmas. By studying the mean extinction times of cooperators and defectors, a variable sensitive to fluctuations, we are able to identify and quantify an emerging 'edge of neutral evolution' that delineates regimes of neutral and Darwinian evolution. Our results reveal that cooperation is significantly maintained in the neutral regimes. In contrast, the classical predictions of evolutionary game theory, where defectors beat cooperators, are recovered in the Darwinian regimes. Our studies demonstrate that fluctuations can provide a surprisingly simple way to partly resolve social dilemmas. Our methods are generally applicable to estimate the role of random drift in evolutionary dynamics.

  6. Net Neutrality in the Netherlands

    NARCIS (Netherlands)

    van Eijk, N.

    2014-01-01

    The Netherlands is among the first countries that have put specific net neutrality standards in place. The decision to implement specific regulation was influenced by at least three factors. The first was the prevailing social and academic debate, partly due to developments in the United States. The

  7. PLT neutral beam injection systems

    International Nuclear Information System (INIS)

    Menon, M.M.; Barber, G.C.; Blue, C.W.

    1979-01-01

    A brief description of the Princeton Large Torus (PLT) neutral beam injection system is given and its performance characteristics are outlined. A detailed operational procedure is included, as are some tips on troubleshooting. Proper operation of the source is shown to be a crucial factor in system performance

  8. Money neutrality: Rethinking the myth

    Directory of Open Access Journals (Sweden)

    Issaoui Fakhri

    2015-01-01

    Full Text Available Considered as an axiomatic basis of classical, neoclassical, and monetarist theories, the long-run money neutrality assumption does not always seem to be verified. Indeed, in our view, the money, in the sense of M2, can constitute a long-run channel of growth transmission. Thus, this paper examines the long-term relationship among money supply (M2, income (GDP, and prices (CPI. The subprime crisis in 2007 has shown that the demand for money does not only meet motives of transaction, precaution, and speculation but also of fictional or quasi-fictional future demands due to the fact that they are created without real counterparts. The capacity of production systems in developed countries to respond to increases in money supply by creating more wealth, involves the assumption of money neutrality in the long-run. However, in developing countries, the excess of money supply may lead to inflation trends. The present study has confirmed the long-term non-neutrality of money supply in the USA, and its neutrality in Gabon and Morocco.

  9. Laser cooling of neutral atoms

    International Nuclear Information System (INIS)

    1993-01-01

    A qualitative description of laser cooling of neutral atoms is given. Two of the most important mechanisms utilized in laser cooling, the so-called Doppler Cooling and Sisyphus Cooling, are reviewed. The minimum temperature reached by the atoms is derived using simple arguments. (Author) 7 refs

  10. RE: Pedagogy--After Neutrality

    Science.gov (United States)

    I'Anson, John

    2010-01-01

    Within the UK and in many parts of the world, official accounts of what it is to make sense of religion are framed within a rhetorics of neutrality in which such study is premised upon the possibility of dispassionate engagement and analysis. This paper, which is largely theoretical in scope, explores both the affordances and the costs of such an…

  11. Addition of N-glycosylation sites on the globular head of the H5 hemagglutinin induces the escape of highly pathogenic avian influenza A H5N1 viruses from vaccine-induced immunity.

    Science.gov (United States)

    Hervé, Pierre-Louis; Lorin, Valérie; Jouvion, Grégory; Da Costa, Bruno; Escriou, Nicolas

    2015-12-01

    Highly pathogenic avian influenza A H5N1 viruses remain endemic in poultry in several countries and still constitute a pandemic threat. Since the early 20th century, we experienced four influenza A pandemics. H3N2 and H1N1pdm09 viruses that respectively emerged during 1968 and 2009 pandemics are still responsible for seasonal epidemics. These viruses evolve regularly by substitutions in antigenic sites of the hemagglutinin (HA), which prevent neutralization by antibodies directed against previous strains (antigenic drift). For seasonal H3N2 viruses, an addition of N-glycosylation sites (glycosites) on H3 contributed to this drift. Here, we questioned whether additional glycosites on H5 could induce an escape of H5N1 virus from neutralization, as it was observed for seasonal H3N2 viruses. Seven H5N1 mutants were produced by adding glycosites on H5. The most glycosylated virus escaped from neutralizing antibodies, in vitro and in vivo. Furthermore, a single additional glycosite was responsible for this escape. Copyright © 2015 Elsevier Inc. All rights reserved.

  12. Phenotypic deficits in the HIV-1 envelope are associated with the maturation of a V2-directed broadly neutralizing antibody lineage

    Science.gov (United States)

    Uhr, Therese; Weber, Jacqueline; Morris, Lynn; Moore, Penny L.

    2018-01-01

    Broadly neutralizing antibodies (bnAbs) to HIV-1 can evolve after years of an iterative process of virus escape and antibody adaptation that HIV-1 vaccine design seeks to mimic. To enable this, properties that render HIV-1 envelopes (Env) capable of eliciting bnAb responses need to be defined. Here, we followed the evolution of the V2 apex directed bnAb lineage VRC26 in the HIV-1 subtype C superinfected donor CAP256 to investigate the phenotypic changes of the virus populations circulating before and during the early phases of bnAb induction. Longitudinal viruses that evolved from the VRC26-resistant primary infecting (PI) virus, the VRC26-sensitive superinfecting (SU) virus and ensuing PI-SU recombinants revealed substantial phenotypic changes in Env, with a switch in Env properties coinciding with early resistance to VRC26. Decreased sensitivity of SU-like viruses to VRC26 was linked with reduced infectivity, altered entry kinetics and lower sensitivity to neutralization after CD4 attachment. VRC26 maintained neutralization activity against cell-associated CAP256 virus, indicating that escape through the cell-cell transmission route is not a dominant escape pathway. Reduced fitness of the early escape variants and sustained sensitivity in cell-cell transmission are both features that limit virus replication, thereby impeding rapid escape. This supports a scenario where VRC26 allowed only partial viral escape for a prolonged period, possibly increasing the time window for bnAb maturation. Collectively, our data highlight the phenotypic plasticity of the HIV-1 Env in evading bnAb pressure and the need to consider phenotypic traits when selecting and designing Env immunogens. Combinations of Env variants with differential phenotypic patterns and bnAb sensitivity, as we describe here for CAP256, may maximize the potential for inducing bnAb responses by vaccination. PMID:29370298

  13. Phenotypic deficits in the HIV-1 envelope are associated with the maturation of a V2-directed broadly neutralizing antibody lineage.

    Directory of Open Access Journals (Sweden)

    Lucia Reh

    2018-01-01

    Full Text Available Broadly neutralizing antibodies (bnAbs to HIV-1 can evolve after years of an iterative process of virus escape and antibody adaptation that HIV-1 vaccine design seeks to mimic. To enable this, properties that render HIV-1 envelopes (Env capable of eliciting bnAb responses need to be defined. Here, we followed the evolution of the V2 apex directed bnAb lineage VRC26 in the HIV-1 subtype C superinfected donor CAP256 to investigate the phenotypic changes of the virus populations circulating before and during the early phases of bnAb induction. Longitudinal viruses that evolved from the VRC26-resistant primary infecting (PI virus, the VRC26-sensitive superinfecting (SU virus and ensuing PI-SU recombinants revealed substantial phenotypic changes in Env, with a switch in Env properties coinciding with early resistance to VRC26. Decreased sensitivity of SU-like viruses to VRC26 was linked with reduced infectivity, altered entry kinetics and lower sensitivity to neutralization after CD4 attachment. VRC26 maintained neutralization activity against cell-associated CAP256 virus, indicating that escape through the cell-cell transmission route is not a dominant escape pathway. Reduced fitness of the early escape variants and sustained sensitivity in cell-cell transmission are both features that limit virus replication, thereby impeding rapid escape. This supports a scenario where VRC26 allowed only partial viral escape for a prolonged period, possibly increasing the time window for bnAb maturation. Collectively, our data highlight the phenotypic plasticity of the HIV-1 Env in evading bnAb pressure and the need to consider phenotypic traits when selecting and designing Env immunogens. Combinations of Env variants with differential phenotypic patterns and bnAb sensitivity, as we describe here for CAP256, may maximize the potential for inducing bnAb responses by vaccination.

  14. The effect of gene drive on containment of transgenic mosquitoes.

    Science.gov (United States)

    Marshall, John M

    2009-05-21

    Mosquito-borne diseases such as malaria and dengue fever continue to be a major health problem through much of the world. Several new potential approaches to disease control utilize gene drive to spread anti-pathogen genes into the mosquito population. Prior to a release, these projects will require trials in outdoor cages from which transgenic mosquitoes may escape, albeit in small numbers. Most genes introduced in small numbers are very likely to be lost from the environment; however, gene drive mechanisms enhance the invasiveness of introduced genes. Consequently, introduced transgenes may be more likely to persist than ordinary genes following an accidental release. Here, we develop stochastic models to analyze the loss probabilities for several gene drive mechanisms, including homing endonuclease genes, transposable elements, Medea elements, the intracellular bacterium Wolbachia, engineered underdominance genes, and meiotic drive. We find that Medea and Wolbachia present the best compromise between invasiveness and containment for the six gene drive systems currently being considered for the control of mosquito-borne disease.

  15. Quantification of Nociceptive Escape Response in C.elegans

    Science.gov (United States)

    Leung, Kawai; Mohammadi, Aylia; Ryu, William; Nemenman, Ilya

    2013-03-01

    Animals cannot rank and communicate their pain consciously. Thus in pain studies on animal models, one must infer the pain level from high precision experimental characterization of behavior. This is not trivial since behaviors are very complex and multidimensional. Here we explore the feasibility of C.elegans as a model for pain transduction. The nematode has a robust neurally mediated noxious escape response, which we show to be partially decoupled from other sensory behaviors. We develop a nociceptive behavioral response assay that allows us to apply controlled levels of pain by locally heating worms with an IR laser. The worms' motions are captured by machine vision programming with high spatiotemporal resolution. The resulting behavioral quantification allows us to build a statistical model for inference of the experienced pain level from the behavioral response. Based on the measured nociceptive escape of over 400 worms, we conclude that none of the simple characteristics of the response are reliable indicators of the laser pulse strength. Nonetheless, a more reliable statistical inference of the pain stimulus level from the measured behavior is possible based on a complexity-controlled regression model that takes into account the entire worm behavioral output. This work was partially supported by NSF grant No. IOS/1208126 and HFSP grant No. RGY0084/2011.

  16. Naloxone facilitates appetitive extinction and eliminates escape from frustration.

    Science.gov (United States)

    Norris, Jacob N; Pérez-Acosta, Andrés M; Ortega, Leonardo A; Papini, Mauricio R

    2009-11-01

    Two experiments tested the effects of opioid receptor blockage on behavior. In Experiment 1, rats reinforced for lever pressing with either sucrose or food pellets received treatment with saline, 2, and 10 mg/kg naloxone, i.p. (within-subject design). Naloxone 10 mg/kg increased response latency, but 2 mg/kg had no effect. When shifted to extinction (between-group design), naloxone (2 and 10 mg/kg) facilitated extinction relative to saline animals, after reinforcement with either sucrose or food pellets. In Experiment 2, after 10 sessions of access to 32% sucrose or an empty tube (between-group design), all rats were exposed to the empty tube while allowing them to jump over a barrier into a different compartment. Escape latencies were shorter for downshifted saline than for saline rats always given access to the empty tube. This escape-from-frustration effect was eliminated by naloxone (2 mg/kg, i.p.). Opioid blockage appears to reduce the value of alternative incentives.

  17. Ultra-fast Escape of a Octopus-inspired Rocket

    Science.gov (United States)

    Weymouth, Gabriel; Triantafyllou, Michael

    2013-11-01

    The octopus, squid, and other cephalopods inflate with water and then release a jet to accelerate in the opposite direction. This escape mechanism is particularly interesting in the octopus because they become initially quite bluff, yet this does not hinder them in achieving impressive bursts of speed. We examine this somewhat paradoxical maneuver using a simple deflating spheroid model in both potential and viscous flow. We demonstrate that the dynamic reduction of the width of the body completely changes the flow and forces acting on the escaping rocket in three ways. First, a body which reduces in size can generate an added mass thrust which counteracts the added mass inertia. Second, the motion of the shrinking wall acts similar to suction on a static wall, reducing separation and drag forces in a viscous fluid, but that this effects depends on the rate of size change. Third, using a combination of these two features it is possible to initially load the fluid with kinetic energy when heavy and bluff and then recover that energy when streamlined and light, enabling ultra-fast accelerations. As a notable example, these mechanisms allow a shrinking spheroid rocket in a heavy inviscid fluid to achieve speeds greater than an identical rocket in the vacuum of space. Southampton Marine and Maritime Institute.

  18. Fundamentals of a Multi-Phase, Neutral-Point Clamped Multilevel ...

    African Journals Online (AJOL)

    The conventional five-level diode-clamped inverter suffers from the problem of many active power switches when extended to multiphase system. As a consequence, increasing number of gate drive circuits are required; resulting in complex system circuitry. This paper presents the fundamentals of a multiphase, neutral ...

  19. Control rod drives

    International Nuclear Information System (INIS)

    Hayakawa, Hiroyasu.

    1979-01-01

    Purpose: To enable rapid control in a simple circuit by providing a motor control device having an electric capacity capable of simultaneously driving all of the control rods rapidly only in the inserting direction as well as a motor controlling device capable of fine control for the insertion and extraction at usual operation. Constitution: The control rod drives comprise a first motor control device capable of finely controlling the control rods both in inserting and extracting directions, a second motor control device capable of rapidly driving the control rods only in the inserting direction, and a first motor switching circuit and a second motor switching circuit switched by switches. Upon issue of a rapid insertion instruction for the control rods, the second motor switching circuit is closed by the switch and the second motor control circuit and driving motors are connected. Thus, each of the control rod driving motors is driven at a high speed in the inserting direction to rapidly insert all of the control rods. (Yoshino, Y.)

  20. Broad Neutralization as a Byproduct of Antibody Maturation during HIV-1 Infection: a Personal Perspective

    Directory of Open Access Journals (Sweden)

    Feng Gao

    2016-07-01

    Full Text Available Broadly neutralizing antibodies (bnAbs may be key for an effective HIV-1 vaccine. Although bnAbs can be detected in a small percentage of HIV-1-infected individuals, they have not been successfully elicited by any vaccines. Germline ancestors of bnAbs generally do not neutralize HIV-1, but they can gradually gain potency and breadth for neutralization of heterologous HIV-1 strains when they become more mature through accumulation of high levels of somatic mutations after a few years of infection. Since bnAbs develop in the absence of diverse heterologous HIV-1 variants in an infected individual, one plausible hypothesis is that broad neutralization of diverse heterologous viruses is a byproduct of the antibody maturation process. This hypothesis is supported by observations that bnAbs continuously evolve to gain neutralization breadth and potency, even after the vast majority of autologous plasma viruses become resistant to bnAbs in infected individuals. Importantly, those individuals do not benefit from the development of continuously more matured bnAbs because autologous viruses have completely escaped from these bnAbs. This theory may have significant implication in AIDS vaccine development.

  1. H7N9 influenza virus neutralizing antibodies that possess few somatic mutations.

    Science.gov (United States)

    Thornburg, Natalie J; Zhang, Heng; Bangaru, Sandhya; Sapparapu, Gopal; Kose, Nurgun; Lampley, Rebecca M; Bombardi, Robin G; Yu, Yingchun; Graham, Stephen; Branchizio, Andre; Yoder, Sandra M; Rock, Michael T; Creech, C Buddy; Edwards, Kathryn M; Lee, David; Li, Sheng; Wilson, Ian A; García-Sastre, Adolfo; Albrecht, Randy A; Crowe, James E

    2016-04-01

    Avian H7N9 influenza viruses are group 2 influenza A viruses that have been identified as the etiologic agent for a current major outbreak that began in China in 2013 and may pose a pandemic threat. Here, we examined the human H7-reactive antibody response in 75 recipients of a monovalent inactivated A/Shanghai/02/2013 H7N9 vaccine. After 2 doses of vaccine, the majority of donors had memory B cells that secreted IgGs specific for H7 HA, with dominant responses against single HA subtypes, although frequencies of H7-reactive B cells ranged widely between donors. We isolated 12 naturally occurring mAbs with low half-maximal effective concentrations for binding, 5 of which possessed neutralizing and HA-inhibiting activities. The 5 neutralizing mAbs exhibited narrow breadth of reactivity with influenza H7 strains. Epitope-mapping studies using neutralization escape mutant analysis, deuterium exchange mass spectrometry, and x-ray crystallography revealed that these neutralizing mAbs bind near the receptor-binding pocket on HA. All 5 neutralizing mAbs possessed low numbers of somatic mutations, suggesting the clones arose from naive B cells. The most potent mAb, H7.167, was tested as a prophylactic treatment in a mouse intranasal virus challenge study, and systemic administration of the mAb markedly reduced viral lung titers.

  2. Energy composition of high-energy neutral beams on the COMPASS tokamak

    Directory of Open Access Journals (Sweden)

    Mitosinkova Klara

    2016-12-01

    Full Text Available The COMPASS tokamak is equipped with two identical neutral beam injectors (NBI for additional plasma heating. They provide a beam of deuterium atoms with a power of up to ~(2 × 300 kW. We show that the neutral beam is not monoenergetic but contains several energy components. An accurate knowledge of the neutral beam power in each individual energy component is essential for a detailed description of the beam- -plasma interaction and better understanding of the NBI heating processes in the COMPASS tokamak. This paper describes the determination of individual energy components in the neutral beam from intensities of the Doppler-shifted Dα lines, which are measured by a high-resolution spectrometer viewing the neutral beam-line at the exit of NBI. Furthermore, the divergence of beamlets escaping single aperture of the last accelerating grid is deduced from the width of the Doppler-shifted lines. Recently, one of the NBI systems was modified by the removal of the Faraday copper shield from the ion source. The comparison of the beam composition and the beamlet divergence before and after this modification is also presented.

  3. Orbital and escape dynamics in barred galaxies - III. The 3D system: correlations between the basins of escape and the NHIMs

    Science.gov (United States)

    Zotos, Euaggelos E.; Jung, Christof

    2018-01-01

    The escape dynamics of the stars in a barred galaxy composed of a spherically symmetric central nucleus, a bar, a flat thin disc and a dark matter halo component is investigated by using a realistic three degrees of freedom (3-d.o.f.) dynamical model. Modern colour-coded diagrams are used for distinguishing between bounded and escaping motion. In addition, the smaller alignment index method is deployed for determining the regular, sticky or chaotic nature of bounded orbits. We reveal the basins of escape corresponding to the escape through the two symmetrical escape channels around the Lagrange points L2 and L3 and also we relate them with the corresponding distribution of the escape times of the orbits. Furthermore, we demonstrate how the stable manifolds, around the index-1 saddle points, accurately define the fractal basin boundaries observed in the colour-coded diagrams. The development scenario of the fundamental vertical Lyapunov periodic orbit is thoroughly explored for obtaining a more complete view of the unfolding of the singular behaviour of the dynamics at the cusp values of the parameters. Finally, we examine how the combination of the most important parameters of the bar (such as the semimajor axis and the angular velocity) influences the observed stellar structures (rings and spirals), which are formed by escaping stars guided by the invariant manifolds near the saddle points.

  4. Integrating geographical information and augmented reality techniques for mobile escape guidelines on nuclear accident sites

    International Nuclear Information System (INIS)

    Tsai, Ming-Kuan; Lee, Yung-Ching; Lu, Chung-Hsin; Chen, Mei-Hsin; Chou, Tien-Yin; Yau, Nie-Jia

    2012-01-01

    During nuclear accidents, when radioactive materials spread into the environment, the people in the affected areas should evacuate immediately. However, few information systems are available regarding escape guidelines for nuclear accidents. Therefore, this study constructs escape guidelines on mobile phones. This application is called Mobile Escape Guidelines (MEG) and adopts two techniques. One technique is the geographical information that offers multiple representations; the other is the augmented reality that provides semi-realistic information services. When this study tested the mobile escape guidelines, the results showed that this application was capable of identifying the correct locations of users, showing the escape routes, filtering geographical layers, and rapidly generating the relief reports. Users could evacuate from nuclear accident sites easily, even without relief personnel, since using slim devices to access the mobile escape guidelines is convenient. Overall, this study is a useful reference for a nuclear accident emergency response.

  5. Neutral atom traps of radioactives

    International Nuclear Information System (INIS)

    Behr, J.A.

    2003-01-01

    Neutral atoms trapped with modern laser cooling techniques offer the promise of improving several broad classes of experiments with radioactive isotopes. In nuclear β decay, neutrino spectroscopy from beta-recoil coincidences, along with highly polarized samples, enable experiments to search for non-Standard Model interactions, test whether parity symmetry is maximally violated, and search for new sources of time reversal violation. Ongoing efforts at TRIUMF, Los Alamos and Berkeley will be highlighted. The traps also offer bright sources for Doppler-free spectroscopy, particularly in high-Z atoms where precision measurements could measure the strength of weak neutral nucleon-nucleon and electron-nucleon interactions. Physics with francium atoms has been vigorously pursued at Stony Brook. Several facilities plan work with radioactive atom traps; concrete plans and efforts at KVI Groningen and Legnaro will be among those summarized. Contributions to the multidisciplinary field of trace analysis will be left up to other presenters

  6. Neutral atom traps of radioactives

    CERN Document Server

    Behr, J A

    2003-01-01

    Neutral atoms trapped with modern laser cooling techniques offer the promise of improving several broad classes of experiments with radioactive isotopes. In nuclear beta decay, neutrino spectroscopy from beta-recoil coincidences, along with highly polarized samples, enable experiments to search for non-Standard Model interactions, test whether parity symmetry is maximally violated, and search for new sources of time reversal violation. Ongoing efforts at TRIUMF, Los Alamos and Berkeley will be highlighted. The traps also offer bright sources for Doppler-free spectroscopy, particularly in high-Z atoms where precision measurements could measure the strength of weak neutral nucleon-nucleon and electron-nucleon interactions. Physics with francium atoms has been vigorously pursued at Stony Brook. Several facilities plan work with radioactive atom traps; concrete plans and efforts at KVI Groningen and Legnaro will be among those summarized. Contributions to the multidisciplinary field of trace analysis will be left...

  7. Radiative lifetimes of neutral samarium

    International Nuclear Information System (INIS)

    Den Hartog, E A; Lawler, J E

    2013-01-01

    Radiative lifetimes of 120 odd-parity levels of neutral samarium, ranging in energy from 17 190 to 33 507 cm −1 , are measured using the technique of time-resolved laser-induced fluorescence on a slow atomic beam. This work is part of an ongoing study of radiative properties of rare earth neutral atoms, and is motivated by research needs in astrophysics and lighting technology. This set of Sm i lifetimes substantially increases the available published lifetime data, with 49 of the 120 level lifetimes measured for the first time. These data, most of which are accurate to ±5%, will be combined with branching fractions determined from Fourier transform spectroscopy to produce a large set of measured Sm i transition probabilities. (paper)

  8. Radiative lifetimes of neutral gadolinium

    International Nuclear Information System (INIS)

    Den Hartog, E A; Bilty, K A; Lawler, J E

    2011-01-01

    The current work is part of an ongoing study of radiative properties of rare earth neutral atoms motivated by research needs in several disparate fields including astrophysics, laser chemistry and lighting technology. Time-resolved laser-induced fluorescence on a slow atomic beam has been used to measure radiative lifetimes, accurate to ±5%, for 136 levels of neutral gadolinium. Of the 136 levels, 6 are odd parity ranging in energy from 32 929 to 36 654 cm -1 , and the remaining 130 are even parity ranging from 17 750 to 34 175 cm -1 . This set of Gd i lifetimes represents a significant extension to the available published data, with 93 of the 136 level lifetimes measured for the first time. These lifetimes will provide the absolute normalization for a large set of measured Gd i transition probabilities.

  9. Radiative lifetimes of neutral neodymium

    International Nuclear Information System (INIS)

    Den Hartog, E A; Fittante, A J; Lawler, J E

    2011-01-01

    This work is part of an on-going study of radiative properties of rare earth neutral atoms. This work is motivated by research needs in several disparate fields including astrophysics and lighting technology. Radiative lifetimes of 100 levels of neutral neodymium are measured using the technique of time-resolved laser-induced fluorescence on a slow atomic beam. Of the 100 levels, 3 are even parity ranging in energy from 25 746 to 26 835 cm -1 , and the remaining 97 are odd parity ranging from 17 787 to 27 786 cm -1 . This set of Nd i lifetimes represents a significant extension to the available published data, with 51 of the 100 level lifetimes measured for the first time. These data, which are accurate to ±5%, provide the absolute normalization for a large set of measured Nd i transition probabilities.

  10. Gears and gear drives

    CERN Document Server

    Jelaska, Damir T

    2012-01-01

    Understanding how gears are formed and how they interact or 'mesh' with each other is essential when designing equipment that uses gears or gear trains. The way in which gear teeth are formed and how they mesh is determined by their geometry and kinematics, which is the topic of this book.  Gears and Gear Drives provides the reader with comprehensive coverage of gears and gear drives. Spur, helical, bevel, worm and planetary gears are all covered, with consideration given to their classification, geometry, kinematics, accuracy control, load capacity and manufacturing. Cylindric

  11. Neutral Pion Photoproduction on Neutron

    Science.gov (United States)

    Bulychev, S. A.; Kudryavtsev, A. E.; Kulikov, V. V.; Martem'yanov, M. A.; Tarasov, V. E.; Briscoe, W. J.; Strakovsky, I. I.

    2017-12-01

    The reaction γ n → π0 n is investigated both theoretically and experimentally as an important step toward determining the electromagnetic coupling constants of the N* and Δ* resonances [1]. We analyze the data on the collisions of γ quanta with energies between 200 and 800 MeV with a deuterium target collected by the A2 experiment in Mainz, Germany. These complement the data for neutral-pion photoproduction on protons obtained by the same experiment [2].

  12. Money neutrality: Rethinking the myth

    OpenAIRE

    Issaoui Fakhri; Boufateh Talel; Guesmi Mourad

    2015-01-01

    Considered as an axiomatic basis of classical, neoclassical, and monetarist theories, the long-run money neutrality assumption does not always seem to be verified. Indeed, in our view, the money, in the sense of M2, can constitute a long-run channel of growth transmission. Thus, this paper examines the long-term relationship among money supply (M2), income (GDP), and prices (CPI). The subprime crisis in 2007 has shown that the demand for money does not only...

  13. Vendor neutral archive in PACS

    International Nuclear Information System (INIS)

    Agarwal, Tapesh Kumar; Sanjeev

    2012-01-01

    An archive is a location containing a collection of records, documents, or other materials of historical importance. An integral part of Picture Archiving and Communication System (PACS) is archiving. When a hospital needs to migrate a PACS vendor, the complete earlier data need to be migrated in the format of the newly procured PACS. It is both time and money consuming. To address this issue, the new concept of vendor neutral archive (VNA) has emerged. A VNA simply decouples the PACS and workstations at the archival layer. This is achieved by developing an application engine that receives, integrates, and transmits the data using the different syntax of a Digital Imaging and Communication in Medicine (DICOM) format. Transferring the data belonging to the old PACS to a new one is performed by a process called migration of data. In VNA, a number of different data migration techniques are available to facilitate transfer from the old PACS to the new one, the choice depending on the speed of migration and the importance of data. The techniques include simple DICOM migration, prefetch-based DICOM migration, medium migration, and the expensive non-DICOM migration. “Vendor neutral” may not be a suitable term, and “architecture neutral,” “PACS neutral,” “content neutral,” or “third-party neutral” are probably better and preferred terms. Notwithstanding this, the VNA acronym has come to stay in both the medical IT user terminology and in vendor nomenclature, and radiologists need to be aware of its impact in PACS across the globe

  14. Neutral beams for magnetic fusion

    International Nuclear Information System (INIS)

    Hooper, B.

    1977-01-01

    Significant advances in forming energetic beams of neutral hydrogen and deuterium atoms have led to a breakthrough in magnetic fusion: neutral beams are now heating plasmas to thermonuclear temperatures, here at LLL and at other laboratories. For example, in our 2XIIB experiment we have injected a 500-A-equivalent current of neutral deuterium atoms at an average energy of 18 keV, producing a dense plasma (10 14 particles/cm 3 ) at thermonuclear energy (14 keV or 160 million kelvins). Currently, LLL and LBL are developing beam energies in the 80- to 120-keV range for our upcoming MFTF experiment, for the TFTR tokamak experiment at Princeton, and for the Doublet III tokamak experiment at General Atomic. These results increase our long-range prospects of producing high-intensity beams of energies in the hundreds or even thousands of kilo-electron-volts, providing us with optimistic extrapolations for realizing power-producing fusion reactors

  15. Vaccination and timing influence SIV immune escape viral dynamics in vivo.

    Directory of Open Access Journals (Sweden)

    Liyen Loh

    2008-01-01

    Full Text Available CD8+ cytotoxic T lymphocytes (CTL can be effective at controlling HIV-1 in humans and SIV in macaques, but their utility is partly offset by mutational escape. The kinetics of CTL escape and reversion of escape mutant viruses upon transmission to MHC-mismatched hosts can help us understand CTL-mediated viral control and the fitness cost extracted by immune escape mutation. Traditional methods for following CTL escape and reversion are, however, insensitive to minor viral quasispecies. We developed sensitive quantitative real-time PCR assays to track the viral load of SIV Gag164-172 KP9 wild-type (WT and escape mutant (EM variants in pigtail macaques. Rapid outgrowth of EM virus occurs during the first few weeks of infection. However, the rate of escape plateaued soon after, revealing a prolonged persistence of WT viremia not detectable by standard cloning and sequencing methods. The rate of escape of KP9 correlated with levels of vaccine-primed KP9-specific CD8+ T cells present at that time. Similarly, when non-KP9 responder (lacking the restricting Mane-A*10 allele macaques were infected with SHIVmn229 stock containing a mixture of EM and WT virus, rapid reversion to WT was observed over the first 2 weeks following infection. However, the rate of reversion to WT slowed dramatically over the first month of infection. The serial quantitation of escape mutant viruses evolving during SIV infection shows that rapid dynamics of immune escape and reversion can be observed in early infection, particularly when CD8 T cells are primed by vaccination. However, these early rapid rates of escape and reversion are transient and followed by a significant slowing in these rates later during infection, highlighting that the rate of escape is significantly influenced by the timing of its occurrence.

  16. Sharks modulate their escape behavior in response to predator size, speed and approach orientation.

    Science.gov (United States)

    Seamone, Scott; Blaine, Tristan; Higham, Timothy E

    2014-12-01

    Escape responses are often critical for surviving predator-prey interactions. Nevertheless, little is known about how predator size, speed and approach orientation impact escape performance, especially in larger prey that are primarily viewed as predators. We used realistic shark models to examine how altering predatory behavior and morphology (size, speed and approach orientation) influences escape behavior and performance in Squalus acanthias, a shark that is preyed upon by apex marine predators. Predator models induced C-start escape responses, and increasing the size and speed of the models triggered a more intense response (increased escape turning rate and acceleration). In addition, increased predator size resulted in greater responsiveness from the sharks. Among the responses, predator approach orientation had the most significant impact on escapes, such that the head-on approach, as compared to the tail-on approach, induced greater reaction distances and increased escape turning rate, speed and acceleration. Thus, the anterior binocular vision in sharks renders them less effective at detecting predators approaching from behind. However, it appears that sharks compensate by performing high-intensity escapes, likely induced by the lateral line system, or by a sudden visual flash of the predator entering their field of view. Our study reveals key aspects of escape behavior in sharks, highlighting the modulation of performance in response to predator approach. Copyright © 2014 Elsevier GmbH. All rights reserved.

  17. Improving escape panel selectivity in Nephrops directed fisheries by actively stimulating fish behaviour

    DEFF Research Database (Denmark)

    Krag, Ludvig Ahm; Herrmann, Bent; Feekings, Jordan P.

    2017-01-01

    with it. To increase the efficiency of such panels, the contact probability needs to be improved. In this study, we investigate to what extent the efficiency of escape panels can be improved by actively stimulating the escape behaviour of fish. The performance of two identical panel sections was compared...... in a twin-trawl system, one with and one without a stimulation device. A new coupled analysis method was used to explicitly quantify the improvements in contact probability and release efficiency for the escape panel. The results demonstrate that by actively stimulating escape behaviour, the contact...

  18. Simulations of Atmospheric Neutral Wave Coupling to the Ionosphere

    Science.gov (United States)

    Siefring, C. L.; Bernhardt, P. A.

    2005-12-01

    atmospheric model for periodic structures with Kelvin-Helmholtz (KH) wavelengths is used to show the development of quasi-periodic structures in the E-layer. For the model, a background atmosphere near 100 km altitude with a scale height of 12.2 km is subjected to a wind shear profile varying by 100 m/s over a distance of 1.7 km. This neutral speed shear drives the KH instability with a growth time of about 100 seconds. The neutral KH wave is a source of plasma turbulence. The E-layer responds to the KH-Wave structure in the neutral atmosphere as an electrodynamic tracer. The plasma flow leads to small scale plasma field aligned irregularities from a gradient drift, plasma interchange instability (GDI) or a Farley-Buneman, two-stream instability (FBI). These irregularities are detected by radar scatter as quasi-periodic structures. All of these plasma phenomena would not occur without the initiation by neutral atmospheric waves.

  19. Comparing Expert and Novice Driving Behavior in a Driving Simulator

    Directory of Open Access Journals (Sweden)

    Hiran B. Ekanayake

    2014-02-01

    Full Text Available This paper presents a study focused on comparing driving behavior of expert and novice drivers in a mid-range driving simulator with the intention of evaluating the validity of driving simulators for driver training. For the investigation, measurements of performance, psychophysiological measurements, and self-reported user experience under different conditions of driving tracks and driving sessions were analyzed. We calculated correlations between quantitative and qualitative measures to enhance the reliability of the findings. The experiment was conducted involving 14 experienced drivers and 17 novice drivers. The results indicate that driving behaviors of expert and novice drivers differ from each other in several ways but it heavily depends on the characteristics of the task. Moreover, our belief is that the analytical framework proposed in this paper can be used as a tool for selecting appropriate driving tasks as well as for evaluating driving performance in driving simulators.

  20. Gaze-controlled Driving

    DEFF Research Database (Denmark)

    Tall, Martin; Alapetite, Alexandre; San Agustin, Javier

    2009-01-01

    We investigate if the gaze (point of regard) can control a remote vehicle driving on a racing track. Five different input devices (on-screen buttons, mouse-pointing low-cost webcam eye tracker and two commercial eye tracking systems) provide heading and speed control on the scene view transmitted...

  1. Drive-Through Training

    Science.gov (United States)

    Carter, Margie

    2010-01-01

    In this article, the author discusses how the early childhood field's approach to staff training reflects the drive-through, fast-food culture. Year after year directors send their teachers to workshops to get some quick refresher techniques. The author suggests that rather than focusing professional development on topics, focus on observing…

  2. Driving While Intoxicated.

    Science.gov (United States)

    Brick, John

    Alcohol intoxication increases the risk of highway accidents, the relative risk of crash probability increasing as a function of blood alcohol content (BAC). Because alcohol use is more prevalent than use of other drugs, more is known about the relationship between alcohol use and driving. Most states presume a BAC of .10% to be evidence of drunk…

  3. Electric-Drive Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    None

    2017-09-01

    Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. These vehicles can be divided into three categories: Hybrid electric vehicles (HEVs), Plug-in hybrid electric vehicles (PHEVs), All-electric vehicles (EVs). Together, PHEVs and EVs can also be referred to as plug-in electric vehicles (PEVs).

  4. Electric-Drive Vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Septon, Kendall K [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

    2017-09-11

    Electric-drive vehicles use electricity as their primary fuel or to improve the efficiency of conventional vehicle designs. These vehicles can be divided into three categories: Hybrid electric vehicles (HEVs), Plug-in hybrid electric vehicles (PHEVs), All-electric vehicles (EVs). Together, PHEVs and EVs can also be referred to as plug-in electric vehicles (PEVs).

  5. Will 3552 Don Quixote escape from the Solar System?

    Directory of Open Access Journals (Sweden)

    Suryadi Siregar

    2011-05-01

    Full Text Available Asteroid 1983 SA, well known as 3552 Don Quixote, is one of Near Earth Asteroids (NEAs which is the most probable candidate for the cometary origin, or otherwise as Jupiter-Family-Comets (JFCs. The aim of this study is to investigate the possibility of 3552 Don Quixote to be ejected from the Solar System. This paper presents an orbital evolution of 100 hypothetical asteroids generated by cloning 3552 Don Quixote. Investigation of its orbital evolution is conducted by using the SWIFT subroutine package, where the gravitational perturbations of eight major planets in the Solar System are considered. Over very short time scales (220 kyr relative to the Solar System life time (10 Gyr, the asteroid 3552 Don Quixote gave an example of chaotic motion that can cause asteroid to move outward and may be followed by escaping from the Solar System. Probability of ejection within the 220 kyr time scale is 50%.

  6. Escape and avoidance learning in the earthworm Eisenia hortensis

    Directory of Open Access Journals (Sweden)

    W. Jeffrey Wilson

    2014-01-01

    Full Text Available Interest in instrumental learning in earthworms dates back to 1912 when Yerkes concluded that they can learn a spatial discrimination in a T-maze. Rosenkoetter and Boice determined in the 1970s that the “learning” that Yerkes observed was probably chemotaxis and not learning at all. We examined a different form of instrumental learning: the ability to learn both to escape and to avoid an aversive stimulus. Freely moving “master” worms could turn off an aversive white light by increasing their movement; the behavior of yoked controls had no effect on the light. We demonstrate that in as few as 12 trials the behavior of the master worms comes under the control of this contingency.

  7. Escaping Antiangiogenic Therapy: Strategies Employed by Cancer Cells

    Directory of Open Access Journals (Sweden)

    Mauricio P. Pinto

    2016-09-01

    Full Text Available Tumor angiogenesis is widely recognized as one of the “hallmarks of cancer”. Consequently, during the last decades the development and testing of commercial angiogenic inhibitors has been a central focus for both basic and clinical cancer research. While antiangiogenic drugs are now incorporated into standard clinical practice, as with all cancer therapies, tumors can eventually become resistant by employing a variety of strategies to receive nutrients and oxygen in the event of therapeutic assault. Herein, we concentrate and review in detail three of the principal mechanisms of antiangiogenic therapy escape: (1 upregulation of compensatory/alternative pathways for angiogenesis; (2 vasculogenic mimicry; and (3 vessel co-option. We suggest that an understanding of how a cancer cell adapts to antiangiogenic therapy may also parallel the mechanisms employed in the bourgeoning tumor and isolated metastatic cells delivering responsible for residual disease. Finally, we speculate on strategies to adapt antiangiogenic therapy for future clinical uses.

  8. Novel Anti-Melanoma Immunotherapies: Disarming Tumor Escape Mechanisms

    Directory of Open Access Journals (Sweden)

    Sivan Sapoznik

    2012-01-01

    Full Text Available The immune system fights cancer and sometimes temporarily eliminates it or reaches an equilibrium stage of tumor growth. However, continuous immunological pressure also selects poorly immunogenic tumor variants that eventually escape the immune control system. Here, we focus on metastatic melanoma, a highly immunogenic tumor, and on anti-melanoma immunotherapies, which recently, especially following the FDA approval of Ipilimumab, gained interest from drug development companies. We describe new immunomodulatory approaches currently in the development pipeline, focus on the novel CEACAM1 immune checkpoint, and compare its potential to the extensively described targets, CTLA4 and PD1. This paper combines multi-disciplinary approaches and describes anti-melanoma immunotherapies from molecular, medical, and business angles.

  9. The resonance escape probability during the neutron slowing down

    International Nuclear Information System (INIS)

    Jehouani, A.; Ghassoun, J.; Aboubeker, A.

    1994-01-01

    Three different methods were used to calculate the neutron resonance escape probability during neutron slowing down in homogeneous media : two Monte Carlo simulations and a determinist method. The first simulation is based on a natural process intervening in neutron transport, the second is a nonanalog simulation while the determinist method is based on an iterative solution of the neutron slowing down equation. The results are in a good agreement for the three methods . The second simulation was found to be more efficient than the first one for high dilutions . In fact we have attained a better figure of merite ( FOM = 1/ (sigma sup 2 ) T) by the second simulation than by the first one . 2 figs. ; 2 refs ( author )

  10. Ability of vaccine strain induced antibodies to neutralize field isolates of caliciviruses from Swedish cats.

    Science.gov (United States)

    Wensman, Jonas Johansson; Samman, Ayman; Lindhe, Anna; Thibault, Jean-Christophe; Berndtsson, Louise Treiberg; Hosie, Margaret J

    2015-12-12

    Feline calicivirus (FCV) is a common cause of upper respiratory tract disease in cats worldwide. Its characteristically high mutation rate leads to escape from the humoral immune response induced by natural infection and/or vaccination and consequently vaccines are not always effective against field isolates. Thus, there is a need to continuously investigate the ability of FCV vaccine strain-induced antibodies to neutralize field isolates. Seventy-eight field isolates of FCV isolated during the years 2008-2012 from Swedish cats displaying clinical signs of upper respiratory tract disease were examined in this study. The field isolates were tested for cross-neutralization using a panel of eight anti-sera raised in four pairs of cats following infection with four vaccine strains (F9, 255, G1 and 431). The anti-sera raised against F9 and 255 neutralised 20.5 and 11.5 %, and 47.4 and 64.1 % of field isolates tested, respectively. The anti-sera against the more recently introduced vaccine strains G1 and 431 neutralized 33.3 and 55.1 % (strain G1) or 69.2 and 89.7 % (strain 431) of the field isolates with titres ≥5. [corrected]. Dual vaccine strains displayed a higher cross-neutralization. This study confirms previous observations that more recently introduced vaccine strains induce antibodies with a higher neutralizing capacity compared to vaccine strains that have been used extensively over a long period of time. This study also suggests that dual FCV vaccine strains might neutralize more field isolates compared to single vaccine strains. Vaccine strains should ideally be selected based on updated knowledge on the antigenic properties of field isolates in the local setting, and there is thus a need for continuously studying the evolution of FCV together with the neutralizing capacity of vaccine strain induced antibodies against field isolates at a national and/or regional level.

  11. Plasma/Neutral-Beam Etching Apparatus

    Science.gov (United States)

    Langer, William; Cohen, Samuel; Cuthbertson, John; Manos, Dennis; Motley, Robert

    1989-01-01

    Energies of neutral particles controllable. Apparatus developed to produce intense beams of reactant atoms for simulating low-Earth-orbit oxygen erosion, for studying beam-gas collisions, and for etching semiconductor substrates. Neutral beam formed by neutralization and reflection of accelerated plasma on metal plate. Plasma ejected from coaxial plasma gun toward neutralizing plate, where turned into beam of atoms or molecules and aimed at substrate to be etched.

  12. RpoS controls the Vibrio cholerae mucosal escape response.

    Directory of Open Access Journals (Sweden)

    Alex Toftgaard Nielsen

    2006-10-01

    Full Text Available Vibrio cholerae causes a severe diarrhoeal disease by secreting a toxin during colonization of the epithelium in the small intestine. Whereas the initial steps of the infectious process have been intensively studied, the last phases have received little attention. Confocal microscopy of V. cholerae O1-infected rabbit ileal loops captured a distinctive stage in the infectious process: 12 h post-inoculation, bacteria detach from the epithelial surface and move into the fluid-filled lumen. Designated the "mucosal escape response," this phenomenon requires RpoS, the stationary phase alternative sigma factor. Quantitative in vivo localization assays corroborated the rpoS phenotype and showed that it also requires HapR. Expression profiling of bacteria isolated from ileal loop fluid and mucus demonstrated a significant RpoS-dependent upregulation of many chemotaxis and motility genes coincident with the emigration of bacteria from the epithelial surface. In stationary phase cultures, RpoS was also required for upregulation of chemotaxis and motility genes, for production of flagella, and for movement of bacteria across low nutrient swarm plates. The hapR mutant produced near-normal numbers of flagellated cells, but was significantly less motile than the wild-type parent. During in vitro growth under virulence-inducing conditions, the rpoS mutant produced 10- to 100-fold more cholera toxin than the wild-type parent. Although the rpoS mutant caused only a small over-expression of the genes encoding cholera toxin in the ileal loop, it resulted in a 30% increase in fluid accumulation compared to the wild-type. Together, these results show that the mucosal escape response is orchestrated by an RpoS-dependent genetic program that activates chemotaxis and motility functions. This may furthermore coincide with reduced virulence gene expression, thus preparing the organism for the next stage in its life cycle.

  13. Initiating a watch list for Ebola virus antibody escape mutations

    Directory of Open Access Journals (Sweden)

    Craig R. Miller

    2016-02-01

    Full Text Available The 2014 Ebola virus (EBOV outbreak in West Africa is the largest in recorded history and resulted in over 11,000 deaths. It is essential that strategies for treatment and containment be developed to avoid future epidemics of this magnitude. With the development of vaccines and antibody-based therapies using the envelope glycoprotein (GP of the 1976 Mayinga strain, one important strategy is to anticipate how the evolution of EBOV might compromise these efforts. In this study we have initiated a watch list of potential antibody escape mutations of EBOV by modeling interactions between GP and the antibody KZ52. The watch list was generated using molecular modeling to estimate stability changes due to mutation. Every possible mutation of GP was considered and the list was generated from those that are predicted to disrupt GP-KZ52 binding but not to disrupt the ability of GP to fold and to form trimers. The resulting watch list contains 34 mutations (one of which has already been seen in humans at six sites in the GP2 subunit. Should mutations from the watch list appear and spread during an epidemic, it warrants attention as these mutations may reflect an evolutionary response from the virus that could reduce the effectiveness of interventions such as vaccination. However, this watch list is incomplete and emphasizes the need for more experimental structures of EBOV interacting with antibodies in order to expand the watch list to other epitopes. We hope that this work provokes experimental research on evolutionary escape in both Ebola and other viral pathogens.

  14. Ion-beam Plasma Neutralization Interaction Images

    Energy Technology Data Exchange (ETDEWEB)

    Igor D. Kaganovich; Edward Startsev; S. Klasky; Ronald C. Davidson

    2002-04-09

    Neutralization of the ion beam charge and current is an important scientific issue for many practical applications. The process of ion beam charge and current neutralization is complex because the excitation of nonlinear plasma waves may occur. Computer simulation images of plasma neutralization of the ion beam pulse are presented.

  15. Neutral beamline with improved ion energy recovery

    Science.gov (United States)

    Kim, Jinchoon

    1984-01-01

    A neutral beamline employing direct energy recovery of unneutralized residual ions is provided which enhances the energy recovery of the full energy ion component of the beam exiting the neutralizer cell, and thus improves the overall neutral beamline efficiency. The unneutralized full energy ions exiting the neutralizer are deflected from the beam path and the electrons in the cell are blocked by a magnetic field applied transverse to the beam direction in the neutral izer exit region. The ions which are generated at essentially ground potential and accelerated through the neutralizer cell by a negative acceleration voltage are collected at ground potential. A neutralizer cell exit end region is provided which allows the magnetic and electric fields acting on the exiting ions to be loosely coupled. As a result, the fractional energy ions exiting the cell are reflected onto and collected at an interior wall of the neutralizer formed by the modified end geometry, and thus do not detract from the energy recovery efficiency of full energy ions exiting the cell. Electrons within the neutralizer are prevented from exiting the neutralizer end opening by the action of crossed fields drift (ExB) and are terminated to a collector collar around the downstream opening of the neutralizer. The correct combination of the extended neutralizer end structure and the magnet region is designed so as to maximize the exit of full energy ions and to contain the fractional energy ions.

  16. Survey of heating and current drive for K-DEMO

    Science.gov (United States)

    Mikkelsen, D. R.; Kessel, C. E.; Poli, F. M.; Bertelli, N.; Kim, K.

    2018-03-01

    We present calculations of heating and current drive by neutral injection and by electromagnetic waves in the ion cyclotron, helicon, lower hybrid, and electron cyclotron frequency ranges for the steady state burn conditions in a K-DEMO configuration with I_p=12.3 MA, a  =  2.1 m, R_o=6.8 m, B_o=7.4 T, \

  17. MAVEN's Imaging UV Spectrograph: Studying Atmospheric Structure and Escape at Mars

    Science.gov (United States)

    Schneider, Nicholas M.; McClintock, W. E.; IUVS Science Team

    2012-10-01

    MAVEN (Mars Volatile and Atmosphere EvolutioN) is a Mars Scout mission slated for launch in November 2013. The key hardware and management partners are University of Colorado, Goddard Space Flight Center, University of California at Berkeley, Lockheed Martin, and the Jet Propulsion Laboratory. MAVEN carries a powerful suite of fields and particles instruments and a sophisticated Imaging UltraViolet Spectrograph (IUVS). In this presentation we will describe IUVS' science goals, instrument design, operational approach and data analysis strategy. IUVS supports the top-level MAVEN science goals: measure the present state of the atmosphere, observe its response to varying solar stimuli, and use the information to estimate loss from Mars' atmosphere over time. The instrument operates at low spectral resolution spanning the FUV and MUV ranges in separate channels, and at high resolution around the hydrogen Lyman alpha line to measure the D/H ratio in the upper atmosphere. MAVEN carries the instrument on an Articulated Payload Platform which orients the instrument for optimal observations during four segments of its 4.5 hr elliptical orbit. During periapse passage, IUVS uses a scan mirror to obtain vertical profiles of emissions from the atmosphere and ionosphere. Around apoapse, the instrument builds up low-resolution images of the atmosphere at multiple wavelengths. In between, the instrument measures emissions from oxygen, hydrogen and deuterium in the corona. IUVS also undertakes day-long stellar occultation campaigns at 2 month intervals, to measure the state of the atmosphere at altitudes below the airglow layer and in situ sampling. All data will be pipeline-processed from line brightnesses to column abundances, local densities and global 3-D maps and provided to the PDS Atmospheres Node. The combined results from all instruments on ion and neutral escape will bear on the central question of the history of Mars' atmosphere and climate change.

  18. Rod drive and latching mechanism

    International Nuclear Information System (INIS)

    Veronesi, L.; Sherwood, D.G.

    1982-01-01

    Hydraulic drive and latching mechanisms for driving reactivity control mechanisms in nuclear reactors are described. Preferably, the pressurized reactor coolant is utilized to raise the drive rod into contact with and to pivot the latching mechanism so as to allow the drive rod to pass the latching mechanism. The pressure in the housing may then be equalized which allows the drive rod to move downwardly into contact with the latching mechanism but to hold the shaft in a raised position with respect to the reactor core. Once again, the reactor coolant pressure may be utilized to raise the drive rod and thus pivot the latching mechanism so that the drive rod passes above the latching mechanism. Again, the mechanism pressure can be equalized which allows the drive rod to fall and pass by the latching mechanism so that the drive rod approaches the reactor core. (author)

  19. Hybrid fluid/kinetic modeling of Pluto’s escaping atmosphere

    Science.gov (United States)

    Erwin, Justin; Tucker, O. J.; Johnson, Robert E.

    2013-09-01

    Predicting the rate of escape and thermal structure of Pluto’s upper atmosphere in preparation for the New Horizons Spacecraft encounter in 2015 is important for planning and interpreting the expected measurements. Having a moderate Jeans parameter Pluto’s atmosphere does not fit the classic definition of Jeans escape for light species escaping from the terrestrial planets, nor does it fit the hydrodynamic outflow from comets and certain exoplanets. It has been proposed for some time that Pluto lies in the region of slow hydrodynamic escape. Using a hybrid fluid/molecular-kinetic model, we previously demonstrated the typical implementation of this model fails to correctly describe the appropriate temperature structure for the upper atmosphere for solar minimum conditions. Here we use a time-dependent solver to allow us to extend those simulations to higher heating rates and we examine fluid models in which Jeans-like escape expressions are used for the upper boundary conditions. We compare these to hybrid simulations of the atmosphere under heating conditions roughly representative of solar minimum and mean conditions as these bracket conditions expected during the New Horizon encounter. Although we find escape rates comparable to those previously estimated by the slow hydrodynamic escape model, and roughly consistent with energy limited escape, our model produces a much more extended atmosphere with higher temperatures roughly consistent with recent observations of CO. Such an extended atmosphere will be affected by Charon and will affect Pluto’s interaction with the solar wind at the New Horizon encounter. For the parameter space covered, we also find an inverse relationship between exobase temperature and altitude and the Jeans escape rate that is consistent with the energy limited escape rate. Since we have previously shown that such models can be scaled, these results have implications for modeling exoplanet atmospheres for which the energy limited

  20. Space station neutral external environment

    Science.gov (United States)

    Ehlers, H.; Leger, L.

    1988-01-01

    Molecular contamination levels arising from the external induced neutral environment of the Space Station (Phase 1 configuration) were calculated using the MOLFLUX model. Predicted molecular column densities and deposition rates generally meet the Space Station contamination requirements. In the doubtful cases of deposition due to materials outgassing, proper material selection, generally excluding organic products exposed to the external environment, must be considered to meet contamination requirements. It is important that the Space Station configuration, once defined, is not significantly modified to avoid introducing new unacceptable contamination sources.

  1. Subauroral Ion-neutral Coupling During the March 2015 Superstorm

    Science.gov (United States)

    Zhang, S.; Erickson, P. J.; Foster, J. C.; Holt, J. M.; Coster, A. J.; Makela, J. J.; Noto, J.; Meriwether, J. W.; Otsuka, Y.; Nicolls, M. J.; McCready, M. A.

    2015-12-01

    The arrival of solar Coronal Mass Ejection materials overlapping a high-speed solar wind stream originated from a nearby coronal hole caused huge magnetic disturbances during March 17-18, 2015. We have coordinated an international campaign to monitor their geospace effects using ground-based facilities, including incoherent scatter radars and Fabry-Perot Interferometers in the America sectors and other instruments in East Asia sectors, forming an observational network along approximately the 60W/120E meridional circle. The presentation will provide highlights of these observations, with a focus on the ion-neutral coupling processes at subauroral and mid-latitudes. One of the most stiking findings is the northward neutral wind surge, observed in multiple sites, accompanying strong westward winds developed at earlier times. We ascribe this unexpected wind disturbances to Subauroal Polarization Stream (SAPS) asscoated strong plasma flows driving ion-neutral coupling. SAPS and strong ion flow were observed by Millstone Hill ISR and DMSP in situ measurements. We will also report the Millstone Hill ISR observations of a significant enhancement in the storm-time molecular ion composition in the F1-region height. This enhancement appears to be caused by strong vertical ion drift due to penetration electric fields.

  2. A rotary drive

    International Nuclear Information System (INIS)

    Causer, R.

    1983-01-01

    A rotary drive for a manipulator or teleoperator comprises a ring member freely rotatable about an eccentric boss extending from an input driver shaft. The ring member has a tapered rim portion wedged between two resiliently biassed friction rings of larger diameter than the ring member and coaxial with the driver shaft, and the ring member is rotatably connected to an output driven shaft. The rotary drive provides a considerable velocity ratio, and also provides a safety feature in that friction between the rim portion and the friction rings only causes rotation of the driven shaft if the load on the driven shaft is less than a certain limiting value. This limiting value may be varied by adjusting the resilient bias on the friction rings. (author)

  3. Driving and engine cycles

    CERN Document Server

    Giakoumis, Evangelos G

    2017-01-01

    This book presents in detail the most important driving and engine cycles used for the certification and testing of new vehicles and engines around the world. It covers chassis and engine-dynamometer cycles for passenger cars, light-duty vans, heavy-duty engines, non-road engines and motorcycles, offering detailed historical information and critical review. The book also provides detailed examples from SI and diesel engines and vehicles operating during various cycles, with a focus on how the engine behaves during transients and how this is reflected in emitted pollutants, CO2 and after-treatment systems operation. It describes the measurement methods for the testing of new vehicles and essential information on the procedure for creating a driving cycle. Lastly, it presents detailed technical specifications on the most important chassis-dynamometer cycles around the world, together with a direct comparison of those cycles.

  4. Drive-by-Downloads

    Energy Technology Data Exchange (ETDEWEB)

    Narvaez, Julia; Endicott-Popovsky, Barbara E.; Seifert, Christian; Aval, Chiraag U.; Frincke, Deborah A.

    2010-02-01

    Abstract: Drive-by-downloads are malware that push, and then execute, malicious code on a client system without the user's consent. The purpose of this paper is to introduce a discussion of the usefulness of antivirus software for detecting the installation of such malware, providing groundwork for future studies. Client honeypots collected drive-by malware which was then evaluated using common antivirus products. Initial analysis showed that most of such antivirus products identified less than 70% of these highly polymorphic malware programs. Also, it was observed that the antivirus products tested, even when successfully detecting this malware, often failed to classify it, leading to the conclusion that further work could involve not only developing new behavioral detection technologies, but also empirical studies that improve general understanding of these threats. Toward that end, one example of malicious code was analyzed behaviorally to provide insight into next steps for the future direction of this research.

  5. Sex Chromosome Drive

    OpenAIRE

    Helleu, Quentin; Gérard, Pierre R.; Montchamp-Moreau, Catherine

    2015-01-01

    Sex chromosome drivers are selfish elements that subvert Mendel's first law of segregation and therefore are overrepresented among the products of meiosis. The sex-biased progeny produced then fuels an extended genetic conflict between the driver and the rest of the genome. Many examples of sex chromosome drive are known, but the occurrence of this phenomenon is probably largely underestimated because of the difficulty to detect it. Remarkably, nearly all sex chromosome drivers are found in t...

  6. Driving electrostatic transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2013-01-01

    Electrostatic transducers represent a very interesting alternative to the traditional inefficient electrodynamic transducers. In order to establish the full potential of these transducers, power amplifiers which fulfill the strict requirements imposed by such loads (high impedance, frequency...... depended, nonlinear and high bias voltage for linearization) must be developed. This paper analyzes power stages and bias configurations suitable for driving an electrostatic transducer. Measurement results of a 300 V prototype amplifier are shown. Measuring THD across a high impedance source is discussed...

  7. Design Drives: materials innovation

    OpenAIRE

    Oliver, Raymond; Toomey, Anne

    2010-01-01

    Design Drives Materials Innovation‘ outlines the potential of a D:STEM (Design, Science, Technology, Engineering amd Mathematics) approach to combining traditionally different fields through design-led, needs driven and technology anchored future products using electro/photo/bio-active polymers in physical formats defined in ‚dots, lines, surfaces and structures‘.It also identifies Ambient Assisted Living as a key driver for future applications.

  8. [Automobile driving capacity in dementia].

    Science.gov (United States)

    Seeger, Rolf

    2015-04-01

    Dementia influences at an early stage the driving aptitude of motor vehicle steering persons. Every year in Switzerland, around 16'000 driving permit holders suffer newly from dementia; therefore the driving aptitude is questioned, especially because of possibly limited executive functions. Individuals with early-stage dementia often may show a dangerous driving stile. However, a mild dementia does not a priori exclude the driving aptitude, and less than half of these drivers can continue driving for another 1 - 3 years. In contrast, there is no further driving aptitude in presence of moderate dementia. In the assessment of driving aptitude, the underlying cause of dementia is always taken into account. Cognitive short tests such as the Mini-Mental Status Exam, Clock Drawing Test and Trail-Making Test are not suitable to make reliable statements about the aptitude to drive, but these tests are very important for the initial diagnosis of dementia in primary care practice and can lead the way for further examination concerning driving aptitude. The legally prescribed regular check-up for motorists aged over 70 years in Switzerland provides an ideal opportunity for early detection of incipient dementia. The practical procedure for the assessment of aptitude to drive in the primary care practice is presented. The physician-guided on-road driving test represents a meaningful, practical and relatively cost-effective tool for the evaluation of driving aptitude in cases of doubt.

  9. Parkinson's disease and driving ability.

    Science.gov (United States)

    Singh, Rajiv; Pentland, Brian; Hunter, John; Provan, Frances

    2007-04-01

    To explore the driving problems associated with Parkinson's disease (PD) and to ascertain whether any clinical features or tests predict driver safety. The driving ability of 154 individuals with PD referred to a driving assessment centre was determined by a combination of clinical tests, reaction times on a test rig and an in-car driving test. The majority of cases (104, 66%) were able to continue driving although 46 individuals required an automatic transmission and 10 others needed car modifications. Ability to drive was predicted by the severity of physical disease, age, presence of other associated medical conditions, particularly dementia, duration of disease, brake reaction, time on a test rig and score on a driving test (all pfeatures in distinguishing safety to drive were severe physical disease (Hoehn and Yahr stage 3), reaction time, moderate disease associated with another medical condition and high score on car testing. Most individuals with PD are safe to drive, although many benefit from car modifications or from using an automatic transmission. A combination of clinical tests and in-car driving assessment will establish safety to drive, and a number of clinical correlates can be shown to predict the likely outcome and may assist in the decision process. This is the largest series of consecutive patients seen at a driving assessment centre reported to date, and the first to devise a scoring system for on-road driving assessment.

  10. The rate of immune escape vanishes when multiple immune responses control an HIV infection

    NARCIS (Netherlands)

    van Deutekom, Hanneke W. M.; Wijnker, Gilles; de Boer, Rob J.

    2013-01-01

    During the first months of HIV infection, the virus typically evolves several immune escape mutations. These mutations are found in epitopes in viral proteins and reduce the impact of the CD8⁺ T cells specific for these epitopes. Recent data show that only a subset of the epitopes escapes, that most

  11. Computer Self-Efficacy, Competitive Anxiety and Flow State: Escaping from Firing Online Game

    Science.gov (United States)

    Hong, Jon-Chao; Pei-Yu, Chiu; Shih, Hsiao-Feng; Lin, Pei-Shin; Hong, Jon-Chao

    2012-01-01

    Flow state in game playing affected by computer self-efficacy and game competitive anxiety was studied. In order to examine the effect of those constructs with high competition, this study select "Escaping from firing online game" which require college students to escape from fire and rescue people and eliminate the fire damage along the way of…

  12. Effects of Visual Information on Wind-Evoked Escape Behavior of the Cricket, Gryllus bimaculatus.

    Science.gov (United States)

    Kanou, Masamichi; Matsuyama, Akane; Takuwa, Hiroyuki

    2014-09-01

    We investigated the effects of visual information on wind-evoked escape behavior in the cricket, Gryllus bimaculatus. Most agitated crickets were found to retreat into a shelter made of cardboard installed in the test arena within a short time. As this behavior was thought to be a type of escape, we confirmed how a visual image of a shelter affected wind-evoked escape behavior. Irrespective of the brightness of the visual background (black or white) or the absence or presence of a shelter, escape jumps were oriented almost 180° opposite to the source of the air puff stimulus. Therefore, the direction of wind-evoked escape depends solely depended on the direction of the stimulus air puff. In contrast, the turning direction of the crickets during the escape was affected by the position of the visual image of the shelter. During the wind-evoked escape jump, most crickets turned in the direction in which a shelter was presented. This behavioral nature is presumably necessary for crickets to retreat into a shelter within a short time after their escape jump.

  13. Spoon Distance Fading with and without Escape Extinction as Treatment for Food Refusal

    Science.gov (United States)

    Rivas, Kristi D.; Piazza, Cathleen C.; Patel, Meeta R.; Bachmeyer, Melanie H.

    2010-01-01

    Little is known about the characteristics of meals that serve as motivating operations (MOs) for escape behavior. In the current investigation, we showed that the distance at which a therapist held a spoon from a child's lips served as an MO for escape behavior. Based on these results, we implemented spoon distance fading, compared fading with and…

  14. Evaluating the potential ecological effects of transgene escape and persistence in constructed plant communities

    Science.gov (United States)

    To date, published studies with herbicide tolerant transgenic crops have failed to demonstrate that transgene escape to wild relatives results in more competitive hybrids. However, it is important to consider transgene escape in the context of the types of traits, which will lik...

  15. Supraventricular escape rhythms during transient episodes of bradycardia in preterm infants

    NARCIS (Netherlands)

    Andriessen, P.; Koolen, A.M.P.; Bastin, F.H.; Lafeber, H.N.; Meijler, F.L.

    2001-01-01

    Objective: To evaluate the origin of transient episodes of sinus bradycardia, atrial escape rhythm, and atrioventricular nodal escape rhythm in preterm infants. Material and methods: The study was observational, and was carried out in a third level neonatal intensive care unit. We srudied 19

  16. Escapement of Cape hakes under the fishing line of the Namibian ...

    African Journals Online (AJOL)

    The objective of this study was to establish whether Cape hakes Merluccius capensis and M. paradoxus escape under the fishing line and to identify any species or length dependence of escape rates. Experiments were carried out in Namibian waters during two cruises in October 2002 and October 2003. A collection bag ...

  17. The Efficacy of Noncontingent Escape for Decreasing Children's Disruptive Behavior during Restorative Dental Treatment

    Science.gov (United States)

    O'Callaghan, Patrick M.; Allen, Keith D.; Powell, Shawn; Salama, Fouad

    2006-01-01

    We evaluated the effectiveness of a dentist-implemented behavioral intervention in which brief escape from dental treatment was provided on a regular basis, independent of the child's behavior. Within a multiple baseline design across subjects, 5 children, ages 4 to 7 years, were provided with temporary escape from dental treatment on a fixed-time…

  18. Control rod drives

    International Nuclear Information System (INIS)

    Sato, Takao; Arita, Setsuo; Mizuno, Katsuhiro.

    1986-01-01

    Purpose: To enable fine positioning by using an induction motor of a simple structure as a driving source and thereby improve the reliability of control rod drives. Constitution: A step actuator is directly coupled with an induction motor, in which the induction motor is connected by way of a pulse driving control circuit to an AC power source, while the step actuator is connected to a DC power source. When a thyristor is turned ON, the motor outputs a positive torque and rotates and starts to rotate in the forward direction. When the other thyristor is turned ON, the motor is applied with braking by a reverse excitation in a manner equivalent to the change for the exciting phase sequence. When the speed is lowered to a predetermined value, braking is actuated by the torque of the step actuator and the motor stops at a zero position or balanced position. In this way, braking is actuated from the decelerating step to the stopping with no abrasion and a highly accurate positioning is possible due to the characteristics of the step actuator. (Horiuchi, T.)

  19. Control rod drive

    International Nuclear Information System (INIS)

    Watando, Kosaku; Tanaka, Yuzo; Mizumura, Yasuhiro; Hosono, Kazuya.

    1975-01-01

    Object: To provide a simple and compact construction of an apparatus for driving a drive shaft inside with a magnetic force from the outside of the primary system water side. Structure: The weight of a plunger provided with an attraction plate is supported by a plunger lift spring means so as to provide a buffer action at the time of momentary movement while also permitting the load on lift coil to be constituted solely by the load on the drive shaft. In addition, by arranging the attraction plate and lift coil so that they face each other with a small gap there-between, it is made possible to reduce the size and permit efficient utilization of the attracting force. Because of the small size, cooling can be simply carried out. Further, since there is no mechanical penetration portion, there is no possibility of leakage of the primary system water. Furthermore, concentration of load on a latch pin is prevented by arranging so that with a structure the load of the control rod to be directly beared through the scrum latch. (Kamimura, M.)

  20. Discrete symmetries with neutral mesons

    Science.gov (United States)

    Bernabéu, José

    2018-01-01

    Symmetries, and Symmetry Breakings, in the Laws of Physics play a crucial role in Fundamental Science. Parity and Charge Conjugation Violations prompted the consideration of Chiral Fields in the construction of the Standard Model, whereas CP-Violation needed at least three families of Quarks leading to Flavour Physics. In this Lecture I discuss the Conceptual Basis and the present experimental results for a Direct Evidence of Separate Reversal-in-Time T, CP and CPT Genuine Asymmetries in Decaying Particles like Neutral Meson Transitions, using Quantum Entanglement and the Decay as a Filtering Measurement. The eight transitions associated to the Flavour-CP eigenstate decay products of entangled neutral mesons have demonstrated with impressive significance a separate evidence of TRV and CPV in Bd-physics, whereas a CPTV asymmetry shows a 2σ effect interpreted as an upper limit. Novel CPTV observables are discussed for K physics at KLOE-2, including the difference between the semileptonic asymmetries from KL and KS, the ratios of double decay rate Intensities to Flavour-CP eigenstate decay products and the ω-effect. Their observation would lead to a change of paradigm beyond Quantum Field Theory, however there is nothing in Quantum Mechanics forbidding CPTV.

  1. Effects of trait anger, driving anger, and driving experience on dangerous driving behavior: A moderated mediation analysis.

    Science.gov (United States)

    Ge, Yan; Zhang, Qian; Zhao, Wenguo; Zhang, Kan; Qu, Weina

    2017-11-01

    To explore the effect of anger behind the wheel on driving behavior and accident involvement has been the subject of many studies. However, few studies have explored the interaction between anger and driving experience on dangerous driving behavior. This study is a moderated mediation analysis of the effect of trait anger, driving anger, and driving experience on driving behavior. A sample of 303 drivers was tested using the Trait Anger Scale (TAS), the Driving Anger Scale (DAS), and the Dula Dangerous Driving Index (DDDI). The results showed that trait anger and driving anger were positively correlated with dangerous driving behavior. Driving anger partially mediated the effect of trait anger on dangerous driving behavior. Driving experience moderated the relationship between trait anger and driving anger. It also moderated the effect of driving anger on dangerous driving behavior. These results suggest that drivers with more driving experience may be safer as they are not easily irritated during driving. © 2017 Wiley Periodicals, Inc.

  2. Progesterone after Estradiol Modulates Shuttle-Cage Escape by Facilitating Volition

    Directory of Open Access Journals (Sweden)

    Darryl J. Mayeaux

    2015-01-01

    Full Text Available In animal models of depression, depression is defined as performance on a learning task. That task is typically escaping a mild electric shock in a shuttle cage by moving from one side of the cage to the other. Ovarian hormones influence learning in other kinds of tasks, and these hormones are associated with depressive symptoms in humans. The role of these hormones in shuttle-cage escape learning, however, is less clear. This study manipulated estradiol and progesterone in ovariectomized female rats to examine their performance in shuttle-cage escape learning without intentionally inducing a depressive-like state. Progesterone, not estradiol, within four hours of testing affected latencies to escape. The improvement produced by progesterone was in the decision to act, not in the speed of learning or speed of escaping. This parallels depression in humans in that depressed people are slower in volition, in their decisions to take action.

  3. Plasma Clouds and Snowplows: Bulk Plasma Escape from Mars Observed by MAVEN

    Science.gov (United States)

    Halekas, J. S.; Brain, D. A.; Ruhunusiri, S.; McFadden, J. P.; Mitchell, D. L.; Mazelle, C.; Connerney, J. E. P.; Harada, Y.; Hara, T.; Espley, J. R.; hide

    2016-01-01

    We present initial Mars Atmosphere and Volatile EvolutioN (MAVEN) observations and preliminary interpretation of bulk plasma loss from Mars. MAVEN particle and field measurements show that planetary heavy ions derived from the Martian atmosphere can escape in the form of discrete coherent structures or "clouds." The ions in these clouds are unmagnetized or weakly magnetized, have velocities well above the escape speed, and lie directly downstream from magnetic field amplifications, suggesting a "snowplow" effect. This postulated escape process, similar to that successfully used to explain the dynamics of active gas releases in the solar wind and terrestrial magnetosheath, relies on momentum transfer from the shocked solar wind protons to the planetary heavy ions, with the electrons and magnetic field acting as intermediaries. Fluxes of planetary ions on the order of 10(exp 7)/sq cm/s can escape by this process, and if it operates regularly, it could contribute 10-20% of the current ion escape from Mars.

  4. Hydrogen and deuterium loss from the terrestrial atmosphere - A quantitative assessment of nonthermal escape fluxes

    Science.gov (United States)

    Yung, Yuk L.; Wen, Jun-Shan; Moses, Julianne I.; Landry, Bridget M.; Allen, Mark; Hsu, Kuang-Jung

    1989-01-01

    A comprehensive one-dimensional photochemical model extending from the middle atmosphere (50 km) to the exobase (432 km) has been used to study the escape of hydrogen and deuterium from the earth's atmosphere. The model incorporates recent advances in chemical kinetics as well as atmospheric observations by satellites, especially the Atmosphere Explorer C satellite. The results suggest that the escape fluxes of both H and D are limited by the upward transport of total hydrogen and total deuterium at the homopause. About one fourth of total hydrogen escape is thermal, the rest being nonthermal. It is shown that escape of D is nonthermal and that charge exchange and polar wind are important mechanisms for the nonthermal escape of H and D.

  5. Escape windows to improve the size selectivity in the Baltic cod trawl fishery

    DEFF Research Database (Denmark)

    Madsen, Niels; Holst, René; Foldager, L.

    2002-01-01

    A rapid decrease of the stock of Baltic cod (Gadus morhua) has provided the incentive to improve the size selectivity in the trawl fishery. Use of escape windows is permitted in the legislation to give means of improving the size selectivity of cod as an alternative to a traditional standard codend....... The history of the use of escape windows in the Baltic Sea cod fishery is reviewed. The present escape windows do not function optimally. The objective of this new experiment was to compare an improved design of escape window, which is placed in the upper panel, with that of standard codend. Three standard...... (WMS) as that of a standard codend. The L50 of the standard codends decreased with catch weight. An unexplained port- starboard effect was found for the window codends where the L50 depended on which of the two trawls the codend was attached to. The potential of these escape windows as a management...

  6. Antarctic krill; assessment of mesh size selectivity and escape mortality from trawls

    DEFF Research Database (Denmark)

    Krafft, Bjørn A.; Krag, Ludvig Ahm; Herrmann, Bent

    2015-01-01

    This working paper presents the aims and methodology for a three-year-project (commenced in 2015) assessing size selectivity and escape mortality of Antarctic krill from trawl nets. The project is widely based on acquired experiences from a completed study Net Escapement of Antarctic krill......Marine AS. The project will examine krill escape mortality from the codend during a full scale field experiment, model size selectivity and escape mortality in codends including different designs and assess the size selectivity in the trawl body forward of the codend. Based on end results from the preceding...... examinations we will be able to predict size selectivity and escape mortality from the entire trawl body with the appurtenant mortality for different trawl designs...

  7. Low Sex Drive in Women

    Science.gov (United States)

    Low sex drive in women Overview Women's sexual desires naturally fluctuate over the years. Highs and lows commonly coincide ... used for mood disorders also can cause low sex drive in women. If your lack of interest ...

  8. Marijuana and actual driving performance

    Science.gov (United States)

    1993-11-01

    This report concerns the effects of marijuana smoking on actual driving performance. It presents the results of one pilot and three actual driving studies. The pilot study's major purpose was to establish the THC dose current marijuana users smoke to...

  9. Nuclear refueling platform drive system

    International Nuclear Information System (INIS)

    Busch, F.R.; Faulstich, D.L.

    1992-01-01

    This patent describes a drive system. It comprises: a gantry including a bridge having longitudinal and transverse axes and supported by spaced first and second end frames joined to fist and second end frames joined to first and second drive trucks for moving the bridge along the transverse axis; first means for driving the first drive truck; second means for driving the second drive truck being independent from the first driving means; and means for controlling the first and second driving means for reducing differential transverse travel between the first and second drive trucks, due to a skewing torque acting on the bridge, to less than a predetermined maximum, the controlling means being in the form of an electrical central processing unit and including: a closed-loop first velocity control means for controlling velocity of the first drive truck by providing a first command signal to the first driver means; a close loop second velocity control means for controlling velocity of the second drive truck by providing a second command signal to the second driving means; and an auxiliary closed-loop travel control means

  10. Optimal Combinations of Broadly Neutralizing Antibodies for Prevention and Treatment of HIV-1 Clade C Infection.

    Directory of Open Access Journals (Sweden)

    Kshitij Wagh

    2016-03-01

    Full Text Available The identification of a new generation of potent broadly neutralizing HIV-1 antibodies (bnAbs has generated substantial interest in their potential use for the prevention and/or treatment of HIV-1 infection. While combinations of bnAbs targeting distinct epitopes on the viral envelope (Env will likely be required to overcome the extraordinary diversity of HIV-1, a key outstanding question is which bnAbs, and how many, will be needed to achieve optimal clinical benefit. We assessed the neutralizing activity of 15 bnAbs targeting four distinct epitopes of Env, including the CD4-binding site (CD4bs, the V1/V2-glycan region, the V3-glycan region, and the gp41 membrane proximal external region (MPER, against a panel of 200 acute/early clade C HIV-1 Env pseudoviruses. A mathematical model was developed that predicted neutralization by a subset of experimentally evaluated bnAb combinations with high accuracy. Using this model, we performed a comprehensive and systematic comparison of the predicted neutralizing activity of over 1,600 possible double, triple, and quadruple bnAb combinations. The most promising bnAb combinations were identified based not only on breadth and potency of neutralization, but also other relevant measures, such as the extent of complete neutralization and instantaneous inhibitory potential (IIP. By this set of criteria, triple and quadruple combinations of bnAbs were identified that were significantly more effective than the best double combinations, and further improved the probability of having multiple bnAbs simultaneously active against a given virus, a requirement that may be critical for countering escape in vivo. These results provide a rationale for advancing bnAb combinations with the best in vitro predictors of success into clinical trials for both the prevention and treatment of HIV-1 infection.

  11. Guidelines for Remote Handling Maintenance of ITER Neutral Beam Components

    International Nuclear Information System (INIS)

    Cordier, J.-J.; Hemsworth, R.; Bayetti, P.

    2006-01-01

    Remote handling maintenance of ITER components is one of the main challenges of the ITER project. This type of maintenance shall be operational for the nuclear phase of exploitation of ITER, and be considered at a very early stage since it significantly impacts on the components design, interfaces management and integration business. A large part of the R/H equipment will be procured by the EU partner, in particular the whole Neutral Beam Remote Handling (RH) equipment package. A great deal of work has already been done in this field during the EDA phase of ITER project, but improvements and alternative option that are now proposed by ITER lead to added RH and maintenance engineering studies. The Neutral Beam Heating -and- Current Drive system 1 is being revisited by the ITER project. The vertical maintenance scheme that is presently considered by ITER, may significantly impact on the reference design of the Neutral Beam (NB) system and associated components and lead to new design of the NB box itself. In addition, revision of both NB cell radiation level zoning and remote handling classification of the beam line injector will also significantly impact on components design and maintenance. Based on the experience gained on the vertical maintenance scheme, developed in detail for the ITER Neutral Beam Test Facility 2 to be built in Europe in a near future, guidelines for the revision of the design and preliminary feasibility study of the remote handling vertical maintenance scheme of beam line components are described in the paper. A maintenance option for the SINGAP3 accelerator is also presented. (author)

  12. Cellular Adhesion Promotes Prostate Cancer Cells Escape from Dormancy.

    Science.gov (United States)

    Ruppender, Nazanin; Larson, Sandy; Lakely, Bryce; Kollath, Lori; Brown, Lisha; Coleman, Ilsa; Coleman, Roger; Nguyen, Holly; Nelson, Peter S; Corey, Eva; Snyder, Linda A; Vessella, Robert L; Morrissey, Colm; Lam, Hung-Ming

    2015-01-01

    Dissemination of prostate cancer (PCa) cells to the bone marrow is an early event in the disease process. In some patients, disseminated tumor cells (DTC) proliferate to form active metastases after a prolonged period of undetectable disease known as tumor dormancy. Identifying mechanisms of PCa dormancy and reactivation remain a challenge partly due to the lack of in vitro models. Here, we characterized in vitro PCa dormancy-reactivation by inducing cells from three patient-derived xenograft (PDX) lines to proliferate through tumor cell contact with each other and with bone marrow stroma. Proliferating PCa cells demonstrated tumor cell-cell contact and integrin clustering by immunofluorescence. Global gene expression analyses on proliferating cells cultured on bone marrow stroma revealed a downregulation of TGFB2 in all of the three proliferating PCa PDX lines when compared to their non-proliferating counterparts. Furthermore, constitutive activation of myosin light chain kinase (MLCK), a downstream effector of integrin-beta1 and TGF-beta2, in non-proliferating cells promoted cell proliferation. This cell proliferation was associated with an upregulation of CDK6 and a downregulation of E2F4. Taken together, our data provide the first clinically relevant in vitro model to support cellular adhesion and downregulation of TGFB2 as a potential mechanism by which PCa cells may escape from dormancy. Targeting the TGF-beta2-associated mechanism could provide novel opportunities to prevent lethal PCa metastasis.

  13. Human embryo immune escape mechanisms rediscovered by the tumor.

    Science.gov (United States)

    Ridolfi, Laura; Petrini, Massimiliano; Fiammenghi, Laura; Riccobon, Angela; Ridolfi, Ruggero

    2009-01-01

    Towards the end of the 1990s, the two opposing theories on immunosurveillance and immunostimulation were extensively studied by researchers in an attempt to understand the complex mechanisms that regulate the relation between tumors and the host's immune system. Both theories probably have elements that would help us to comprehend how the host can induce anti-tumor clinical responses through stimulation of the immune system and which could also give us a deeper insight into the mechanisms of tumor immunosuppression. The model that most resembles the behavior of tumor cells in terms of growth, infiltration and suppression of the immune system of the environment in which they live is undoubtedly that of the embryonic cell. The fetus behaves like an allogenic transplant within the mother's body, using every means it has to escape from and defend itself against the mother's immune system. The majority of these mechanisms are the same as those found in tumor cells: antigenic loss, lack of expression of classic HLA-I molecules, production of immunosuppressive cytokines, induction of lack of expression of co-stimulatory molecules in antigen presenting cells, and induction of apoptosis in infiltrating lymphocytes, with activation of a type Th2 regulatory lymphocyte response. A careful and comparative study of key mechanisms capable of triggering tolerance or cytotoxicity in both embryonic and tumor cells could prove immensely valuable in designing new strategies for anti-tumor immunotherapy.

  14. Modified guidance laws to escape microbursts with turbulence

    Directory of Open Access Journals (Sweden)

    Atilla Dogan

    2002-01-01

    Full Text Available This paper introduces Modified Altitude- and Dive-Guidance laws for escaping a microburst with turbulence. The goal is to develop a procedure to estimate the highest altitude at which an aircraft can fly through a microburst without running into stall. First, a new metric is constructed that quantifies the aircraft upward force capability in a microburst encounter. In the absence of turbulence, the metric is shown to be a decreasing function of altitude. This suggests that descending to a low altitude may improve safety in the sense that the aircraft will have more upward force capability to maintain its altitude. In the presence of stochastic turbulence, the metric is treated as a random variable and its probability distribution function is analytically approximated as a function of altitude. This approximation allows us to determine the highest safe altitude at which the aircraft may descend, hence avoiding to descend too low. This highest safe altitude is used as the commanded altitude in Modified Altitude- and Dive-Guidance. Monte Carlo simulations show that these Modified Altitude- and Dive-Guidance strategies can decrease the probability of minimum altitude being lower than a given value without significantly increasing the probability of crash.

  15. EUROGAM: A high efficiency escape suppressed spectrometer array

    International Nuclear Information System (INIS)

    Nolan, P.J.

    1992-01-01

    EUROGAM is a UK-France collaboration to develop and build a high efficiency escape suppressed spectrometer array. The project has involved the development of both germanium (Ge) and bismuth germanate (BGO) detectors to produce crystals which are both bigger and have a more complex geometry. As a major investment for the future, the collaboration has developed a new electronics and data acquisition system based on the VXI and VME standards. The array will start its experimental programme in mid 1992 at the Nuclear Structure Facility at Daresbury, U.K. At this stage it will have a total photopeak efficiency (for 1.33 MeV gamma-rays) of ∼ 4.5%. This will give an improvement in sensitivity (relative to presently operating arrays) of a factor of about 10. When EUROGAM moves to France in mid 1993 its photopeak efficiency will have increased to about 8.5% which will result in an increase in sensitivity of a further factor of about 10. In this article I will concentrate on the array which will operate at Daresbury in 1992 and only briefly cover the developments which will take place for the full array before it is used in France in 1993. (author). 13 refs., 2 tabs., 10 figs

  16. My car is sinking: automobile submersion, lessons in vehicle escape.

    Science.gov (United States)

    Giesbrecht, Gordon G; McDonald, Gerren K

    2010-08-01

    In North America approximately 400 individuals per year die in submersed vehicles, accounting for 5-11% of all drownings. About half of people surveyed would let the vehicle fill with water before attempting exit. We used a crane and two passenger vehicles of the same make, model, and year-one with passenger compartment intact (I) and one with holes (H) in the floor (area approximately 2200 cm2)--to conduct occupied and unoccupied submersions. Three phases of submersion were identified: 1) FLOATING, vehicles floated for 15 s (H) to 63 s (I) before the water reached the bottom of the side windows; 2) SINKING, the subsequent period until the vehicle is completely under water, but before it fills completely; and 3) SUBMERGED, the vehicle was full of water and several feet below the surface. Total time to submersion was 150 s for I but only 37 s for H. Opening the door to exit Vehicle I decreased submersion time from 150 to 30 s. Even the most difficult exit strategy attempted (three men and a child manikin through one window) was quickly performed from Vehicle I (only 51 s). During one exit attempt, initiated during the sinking phase, it was impossible to open the doors or windows until the vehicle was completely full of water. A vehicle is most easily exited during the initial Floating Phase. We suggest the following escape procedure: SEATBELT(s) unfastened; WINDOWS open; CHILDREN released from restraints and brought close to an adult; and OUT, children should exit first.

  17. Intertextuality in Novel: An Escape from Patriarchal Soliloquy

    Directory of Open Access Journals (Sweden)

    Nargess Bagheri

    2015-12-01

    Full Text Available Hypertextuality is one of the intertextual relationships introduced by Gerard Genette. According to him, hypertextuality includes all the relationships which the hypertext has with the previous text, i.e. the hypotext. However, he does not consider the relationship between these two texts to be in such a way that the hypertext is the interpretation of the hypotext. On the other hand, other theorizers including Bakhtin, regard the conversation between texts a way to escape a one-voiced and dominant discourse. From this viewpoint, the intertextual relationships of Sadegh Hedayat’s The Blind Owl, with Shahrnoush Parsipour’s The Blue Mind and Abbas Maroufi’s The Body of Farhad are in such a way that The Blind Owl can be regarded as a hypotext for the other 2 novels but these two novels interpret the text differently. The present study aims to examine the intertextual relationships between these 3 novels and explore how a multiple-voiced conversation is formed between them.

  18. ESCAPE. Energy Security and ClimAte Policy Evaluation

    International Nuclear Information System (INIS)

    Kessels, J.R.; Bakker, S.J.A.

    2005-05-01

    Climate change and energy supply security policy are currently not integrated in most countries, despite possible synergies. The ESCAPE approach suggests that linking climate change policy with security of energy supply could improve climate change policy at both a national and international level. The report explores the interaction between policies of energy security and climate change and the options of inclusion of energy security issues into national and international post-2012 climate negotiations. It emphasises the importance of the US in this regard and takes a close look at US energy policy documents. It appears that current US energy policy is not directed towards reducing its reliance on imported fossil fuel, even though the government has a strong preference for this. This study shows that measures to reduce import dependency are mostly synergetic with climate policy and gives some options that can be implemented. On an international level, linkages of energy security into post-2012 climate policy may be possible in sectoral bottom-up approaches or technology frameworks. As well, inclusion of a security of supply criterion in international emission trading instruments may provide potential benefits

  19. Tests of escape theory of binge eating among Latinas.

    Science.gov (United States)

    Higgins Neyland, M K; Bardone-Cone, Anna M

    2017-07-01

    Despite comparable prevalence of some eating disorders (e.g., binge eating disorder) among Latinas compared with Caucasians, eating disorders are still thought of as primarily afflicting Caucasian women. This has led to a lag in research on eating disorders among Latinas. Our objective was to test 3 escape theory models involving the culturally specific independent variables of acculturative stress, family disconnection, and discriminatory stress; the mediator of negative affect; and the dependent variable of binge eating frequency. We recruited a female sample of 119 Latinas (78 who have suffered from an eating disorder, 41 who have never had an eating disorder). Results indicated that all of the relationships between culturally specific factors and binge eating were mediated by negative affect, and that there was a significant direct pathway from discriminatory stress to binge eating. Findings from this study can be used to tailor interventions to Latinas who engage in binge eating, targeting culturally specific factors and their relationships with negative affect and binge eating. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

  20. Gargamelle and the neutral currents

    International Nuclear Information System (INIS)

    Rousset, A.

    1996-06-01

    In order to simplify the description of forces, the physicists want to reduce the number of four interactions to a smaller one. They want to unify them. Einstein tried to unify the electromagnetic interaction and the gravitation interaction but it was probably the most difficult to unify. during the sixties, the American physicists Sheldon Glashow and Steven Weinberg and the Pakistani Abdus Salam ( each rewarded by the Nobel price of 1979) propose to unify the weak and electromagnetic interactions interactions under the form of an only interaction, the electro-weak interaction. To check the validity of this theory exist the demonstration by the weak neutral currents. In 1973, European physicians which analyzed photos taken in the bubble chamber called Gargamelle brought the experimental proof. This book tells the story of this discovery. (N.C.)

  1. Laser sputter neutral mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    King, B.V.; Clarke, M.; Hu, H.; Betz [Newcastle Univ., NSW (Australia). Dept. of Physics

    1993-12-31

    Laser sputter neutral mass spectrometry (LSNMS) is an emerging technique for highly sensitive surface analysis. In this technique a target is bombarded with a pulsed beam of keV ions. The sputtered particles are intercepted by a high intensity pulsed laser beam above the surface and ionised with almost 100% efficiency. The photions may then be mass analysed using a quadrupole or, more commonly, using time of flight (TOF) techniques. In this method photoions are extracted from the ionisation region, accelerated to a known energy E{sub o} and strike a channelplate detector a distance `d` away. The flight time `t` of the photoions is then related to their mass by `d` {radical}m / {radical} 2E{sub o} so measurement of `t` allows mass spectra to be obtained. It is found that LSNMS is an emerging technique of great sensitivity and flexibility, useful for both applied analysis and to investigate basic sputtering processes. 4 refs., 3 figs.

  2. TFTR neutral beam power system

    International Nuclear Information System (INIS)

    Deitz, A.; Murray, H.; Winje, R.

    1977-01-01

    The TFTR NB System will be composed of four beam lines, each containing three ion sources presently being developed for TFTR by the Lawrence Berkeley Laboratories (LBL). The Neutral Beam Power System (NBPS) will provide the necessary power required to operate these Ion Sources in both an experimental or operational mode as well as test mode. This paper describes the technical as well as the administrative/management aspects involved in the development and building of this system. The NBPS will combine the aspects of HV pulse (120 kV) and long pulse width (0.5 sec) together to produce a high power system that is unique in the Electrical Engineering field

  3. Offset Compound Gear Drive

    Science.gov (United States)

    Stevens, Mark A.; Handschuh, Robert F.; Lewicki, David G.

    2010-01-01

    The Offset Compound Gear Drive is an in-line, discrete, two-speed device utilizing a special offset compound gear that has both an internal tooth configuration on the input end and external tooth configuration on the output end, thus allowing it to mesh in series, simultaneously, with both a smaller external tooth input gear and a larger internal tooth output gear. This unique geometry and offset axis permits the compound gear to mesh with the smaller diameter input gear and the larger diameter output gear, both of which are on the same central, or primary, centerline. This configuration results in a compact in-line reduction gear set consisting of fewer gears and bearings than a conventional planetary gear train. Switching between the two output ratios is accomplished through a main control clutch and sprag. Power flow to the above is transmitted through concentric power paths. Low-speed operation is accomplished in two meshes. For the purpose of illustrating the low-speed output operation, the following example pitch diameters are given. A 5.0 pitch diameter (PD) input gear to 7.50 PD (internal tooth) intermediate gear (0.667 reduction mesh), and a 7.50 PD (external tooth) intermediate gear to a 10.00 PD output gear (0.750 reduction mesh). Note that it is not required that the intermediate gears on the offset axis be of the same diameter. For this example, the resultant low-speed ratio is 2:1 (output speed = 0.500; product of stage one 0.667 reduction and stage two 0.750 stage reduction). The design is not restricted to the example pitch diameters, or output ratio. From the output gear, power is transmitted through a hollow drive shaft, which, in turn, drives a sprag during which time the main clutch is disengaged.

  4. XUV-Exposed, Non-Hydrostatic Hydrogen-Rich Upper Atmospheres of Terrestrial Planets. Part II: Hydrogen Coronae and Ion Escape

    Science.gov (United States)

    Lammer, Helmut; Holmström, Mats; Panchenko, Mykhaylo; Odert, Petra; Erkaev, Nikolai V.; Leitzinger, Martin; Khodachenko, Maxim L.; Kulikov, Yuri N.; Güdel, Manuel; Hanslmeier, Arnold

    2013-01-01

    Abstract We studied the interactions between the stellar wind plasma flow of a typical M star, such as GJ 436, and the hydrogen-rich upper atmosphere of an Earth-like planet and a “super-Earth” with a radius of 2 REarth and a mass of 10 MEarth, located within the habitable zone at ∼0.24 AU. We investigated the formation of extended atomic hydrogen coronae under the influences of the stellar XUV flux (soft X-rays and EUV), stellar wind density and velocity, shape of a planetary obstacle (e.g., magnetosphere, ionopause), and the loss of planetary pickup ions on the evolution of hydrogen-dominated upper atmospheres. Stellar XUV fluxes that are 1, 10, 50, and 100 times higher compared to that of the present-day Sun were considered, and the formation of high-energy neutral hydrogen clouds around the planets due to the charge-exchange reaction under various stellar conditions was modeled. Charge-exchange between stellar wind protons with planetary hydrogen atoms, and photoionization, lead to the production of initially cold ions of planetary origin. We found that the ion production rates for the studied planets can vary over a wide range, from ∼1.0×1025 s−1 to ∼5.3×1030 s−1, depending on the stellar wind conditions and the assumed XUV exposure of the upper atmosphere. Our findings indicate that most likely the majority of these planetary ions are picked up by the stellar wind and lost from the planet. Finally, we estimated the long-time nonthermal ion pickup escape for the studied planets and compared them with the thermal escape. According to our estimates, nonthermal escape of picked-up ionized hydrogen atoms over a planet's lifetime within the habitable zone of an M dwarf varies between ∼0.4 Earth ocean equivalent amounts of hydrogen (EOH) to <3 EOH and usually is several times smaller in comparison to the thermal atmospheric escape rates. Key Words: Stellar activity—Low-mass stars—Early atmospheres—Earth-like exoplanets—Energetic neutral

  5. Measurement of Driving Terms

    CERN Document Server

    Schmidt, F; Faus-Golfe, A

    2001-01-01

    In 2000 a series of MDs has been performed at the SPS to measure resonance driving terms. Theory predicts that these terms can be determined by harmonic analysis of BPM data recorded after applying single kicks at various amplitudes. Strong sextupoles were introduced to create a sizeable amount of nonlinearities. Experiments at injection energy (26 GeV) with single bunch as well as one experiment at 120 GeV with 84 bunches were carried out. The expected nonlinear content is compared to the experimenteal observation.

  6. Electric drive design methodology

    CERN Document Server

    Jufer, Marcel

    2013-01-01

    An electric drive that is designed or adapted to a specific application must take into account all the elements of the chain of constituent elements in its use and deployment. In addition to the motor, the transmission, power electronics, control, sensors, and electrical protection systems must be taken into account. The motor and the transmission can be optimized and designed to obtain the best energy efficiency assessment, in particular for dynamic nodes. An inventory and a characterization of these various components is proposed as part of this book's examination and explanation

  7. Electrical machines and drives

    CERN Document Server

    Hindmarsh, John

    2002-01-01

    Recent years have brought substantial developments in electrical drive technology, with the appearance of highly rated, very-high-speed power-electronic switches, combined with microcomputer control systems.This popular textbook has been thoroughly revised and updated in the light of these changes. It retains its successful formula of teaching through worked examples, which are put in context with concise explanations of theory, revision of equations and discussion of the engineering implications. Numerous problems are also provided, with answers supplied.The third edition in

  8. Electrical machines & drives

    CERN Document Server

    Hammond, P

    1985-01-01

    Containing approximately 200 problems (100 worked), the text covers a wide range of topics concerning electrical machines, placing particular emphasis upon electrical-machine drive applications. The theory is concisely reviewed and focuses on features common to all machine types. The problems are arranged in order of increasing levels of complexity and discussions of the solutions are included where appropriate to illustrate the engineering implications. This second edition includes an important new chapter on mathematical and computer simulation of machine systems and revised discussions o

  9. Driving electrostatic transducers

    DEFF Research Database (Denmark)

    Nielsen, Dennis; Knott, Arnold; Andersen, Michael A. E.

    2013-01-01

    Electrostatic transducers represent a very interesting alternative to the traditional inefficient electrodynamic transducers. In order to establish the full potential of these transducers, power amplifiers which fulfill the strict requirements imposed by such loads (high impedance, frequency...... depended, nonlinear and high bias voltage for linearization) must be developed. This paper analyzes power stages and bias configurations suitable for driving an electrostatic transducer. Measurement results of a 300 V prototype amplifier are shown. Measuring THD across a high impedance source is discussed......, and a high voltage attenuation interface for an audio analyzer is presented. THD below 0:1% is reported....

  10. Modeling Secondary Neutral Helium in the Heliosphere

    International Nuclear Information System (INIS)

    Müller, Hans-Reinhard; Möbius, Eberhard; Wood, Brian E.

    2016-01-01

    An accurate, analytic heliospheric neutral test-particle code for helium atoms from the interstellar medium (ISM) is coupled to global heliospheric models dominated by hydrogen and protons from the solar wind and the ISM. This coupling enables the forward-calculation of secondary helium neutrals from first principles. Secondaries are produced predominantly in the outer heliosheath, upwind of the heliopause, by charge exchange of helium ions with neutral atoms. The forward model integrates the secondary production terms along neutral trajectories and calculates the combined neutral helium phase space density in the innermost heliosphere where it can be related to in-situ observations. The phase space density of the secondary component is lower than that of primary neutral helium, but its presence can change the analysis of primaries and the ISM, and can yield valuable insight into the characteristics of the plasma in the outer heliosheath. (paper)

  11. BEAMS3D Neutral Beam Injection Model

    Energy Technology Data Exchange (ETDEWEB)

    Lazerson, Samuel

    2014-04-14

    With the advent of applied 3D fi elds in Tokamaks and modern high performance stellarators, a need has arisen to address non-axisymmetric effects on neutral beam heating and fueling. We report on the development of a fully 3D neutral beam injection (NBI) model, BEAMS3D, which addresses this need by coupling 3D equilibria to a guiding center code capable of modeling neutral and charged particle trajectories across the separatrix and into the plasma core. Ionization, neutralization, charge-exchange, viscous velocity reduction, and pitch angle scattering are modeled with the ADAS atomic physics database [1]. Benchmark calculations are presented to validate the collisionless particle orbits, neutral beam injection model, frictional drag, and pitch angle scattering effects. A calculation of neutral beam heating in the NCSX device is performed, highlighting the capability of the code to handle 3D magnetic fields.

  12. Means of escape provisions and evacuation simulation of public building in Malaysia and Singapore

    Science.gov (United States)

    Samad, Muna Hanim Abdul; Taib, Nooriati; Ying, Choo Siew

    2017-10-01

    The Uniform Building By-law 1984 of Malaysia is the legal document governing fire safety requirements in buildings. Its prescriptive nature has made the requirements out dated from the viewpoint of current performance based approach in most developed countries. The means of escape provisions is a critical requirement to safeguard occupants' safety in fire especially in public buildings. As stipulated in the UBBL 1984, the means of escape provisions includes sufficient escape routes, travel distance, protection of escape routes, etc. designated as means to allow occupants to escape within a safe period of time. This research aims at investigating the effectiveness of those provisions in public buildings during evacuation process involving massive crowd during emergencies. This research includes a scenario-based study on evacuation processes using two software i.e. PyroSim, a crowd modelling software to conduct smoke study and Pathfinder to stimulate evacuation model of building in Malaysia and Singapore as comparative study. The results show that the buildings used as case study were designed according to Malaysian UBBL 1984 and Singapore Firecode, 2013 respectively provide relative safe means of escape. The simulations of fire and smoke and coupled with simulation of evacuation have demonstrated that although there are adequate exits designated according to fire requirements, the impact of the geometry of atriums on the behavior of fire and smoke have significant effect on escape time especially for unfamiliar user of the premises.

  13. Escape of quantum particles from an open nano-circular microcavity

    International Nuclear Information System (INIS)

    Liu, Sheng; Wang, De-hua

    2014-01-01

    When a laser is irradiated on a negative ion, it will provide a coherent, mono-energetic source of detached electrons propagating out from the location of the negative ion. The total escape probability density of the electrons when the negative ion is placed inside an open nano-circular microcavity has been studied on the basis of the semiclassical theory. It is shown that significant oscillations appear in the total escape probability density due to the quantum interference effects. Besides, our study suggests that the escape probability density depends on the laser polarization sensitively. In order to show the correspondence between the escaped probability density and the detached electron's escaped orbits clearly, we calculate the path length spectrum and find that each peak corresponds to the length of one detached electron's escaped orbit. This study provides an example where the quantum nature of the electron's wave function can be observed in the macroscopic world. Our study may guide the future experimental research on the escape and transport process of particles through semiconductor microjunctions.

  14. Reporter Assay for Endo/Lysosomal Escape of Toxin-Based Therapeutics

    Directory of Open Access Journals (Sweden)

    Roger Gilabert-Oriol

    2014-05-01

    Full Text Available Protein-based therapeutics with cytosolic targets are capable of exhibiting their therapeutic effect once they have escaped from the endosomes or lysosomes. In this study, the reporters—horseradish peroxidase (HRP, Alexa Fluor 488 (Alexa and ricin A-chain (RTA—were investigated for their capacity to monitor the endo/lysosomal escape of the ribosome-inactivating protein, saporin. The conjugates—saporin-HRP, Alexasaporin and saporin-KQ-RTA—were constructed, and the endo/lysosomal escape of these conjugates alone (lack of endo/lysosomal release or in combination with certain structurally-specific triterpenoidal saponins (efficient endo/lysosomal escape was characterized. HRP failed in reporting the endo/lysosomal escape of saporin. Contrastingly, Alexa Fluor 488 successfully allowed the report of the process at a toxin concentration of 1000 nM. In addition, single endo/lysosome analysis facilitated the determination of the amount of Alexasaporin released from each vesicle. RTA was also successful in reporting the endo/lysosomal escape of the enzymatically inactive mutant, saporin-KQ, but in this case, the sensitivity of the method reached a toxin concentration of 10 nM. In conclusion, the simultaneous usage of Alexa Fluor 488 and RTA as reporters may provide the possibility of monitoring the endo/lysosomal escape of protein-based therapeutics in the concentration range of 10–1000 nM.

  15. Glaucoma and Driving: On-Road Driving Characteristics.

    Science.gov (United States)

    Wood, Joanne M; Black, Alex A; Mallon, Kerry; Thomas, Ravi; Owsley, Cynthia

    2016-01-01

    To comprehensively investigate the types of driving errors and locations that are most problematic for older drivers with glaucoma compared to those without glaucoma using a standardized on-road assessment. Participants included 75 drivers with glaucoma (mean = 73.2±6.0 years) with mild to moderate field loss (better-eye MD = -1.21 dB; worse-eye MD = -7.75 dB) and 70 age-matched controls without glaucoma (mean = 72.6 ± 5.0 years). On-road driving performance was assessed in a dual-brake vehicle by an occupational therapist using a standardized scoring system which assessed the types of driving errors and the locations where they were made and the number of critical errors that required an instructor intervention. Driving safety was rated on a 10-point scale. Self-reported driving ability and difficulties were recorded using the Driving Habits Questionnaire. Drivers with glaucoma were rated as significantly less safe, made more driving errors, and had almost double the rate of critical errors than those without glaucoma. Driving errors involved lane positioning and planning/approach, and were significantly more likely to occur at traffic lights and yield/give-way intersections. There were few between group differences in self-reported driving ability. Older drivers with glaucoma with even mild to moderate field loss exhibit impairments in driving ability, particularly during complex driving situations that involve tactical problems with lane-position, planning ahead and observation. These results, together with the fact that these drivers self-report their driving to be relatively good, reinforce the need for evidence-based on-road assessments for evaluating driving fitness.

  16. Control rod drives

    International Nuclear Information System (INIS)

    Oonuki, Koji.

    1981-01-01

    Purpose: To increase the driving speed of control rods at rapid insertion with an elongate control rod and an extension pipe while ensuring sufficient buffering performance in a short buffering distance, by providing a plurality of buffers to an extension pipe between a control rod drive source and a control rod in LMFBR type reactor. Constitution: First, second and third buffers are respectively provided to an acceleration piston, an extension pipe and a control rod respectively and the insertion positions for each of the buffers are displaced orderly from above to below. Upon disconnection of energizing current for an electromagnet, the acceleration piston, the extension pipe and the control rod are rapidly inserted in one body. The first, second and third buffers are respectively actuated at each of their falling strokes upon rapid insertion respectively, and the acceleration piston, the extension pipe and the control rod receive the deceleration effect in the order correspondingly. Although the compression force is applied to the control rod only near the stroke end, it does not cause deformation. (Kawakami, Y.)

  17. Polar drive on OMEGA

    Directory of Open Access Journals (Sweden)

    Radha P.B.

    2013-11-01

    Full Text Available High-convergence polar-drive experiments are being conducted on OMEGA [T. R. Boehly et al., Opt. Commum. 133, 495 (1997] using triple-picket laser pulses. The goal of OMEGA experiments is to validate modeling of oblique laser deposition, heat conduction in the presence of nonradial thermal gradients in the corona, and implosion energetics in the presence of laser–plasma interactions such as crossed-beam energy transfer. Simulated shock velocities near the equator, where the beams are obliquely incident, are within 5% of experimentally inferred values in warm plastic shells, well within the required accuracy for ignition. High, near-one-dimensional areal density is obtained in warm-plastic-shell implosions. Simulated backlit images of the compressing core are in good agreement with measured images. Outstanding questions that will be addressed in the future relate to the role of cross-beam transfer in polar drive irradiation and increasing the energy coupled into the target by decreasing beam obliquity.

  18. On implicit abstract neutral nonlinear differential equations

    Energy Technology Data Exchange (ETDEWEB)

    Hernández, Eduardo, E-mail: lalohm@ffclrp.usp.br [Universidade de São Paulo, Departamento de Computação e Matemática, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto (Brazil); O’Regan, Donal, E-mail: donal.oregan@nuigalway.ie [National University of Ireland, School of Mathematics, Statistics and Applied Mathematics (Ireland)

    2016-04-15

    In this paper we continue our developments in Hernández and O’Regan (J Funct Anal 261:3457–3481, 2011) on the existence of solutions for abstract neutral differential equations. In particular we extend the results in Hernández and O’Regan (J Funct Anal 261:3457–3481, 2011) for the case of implicit nonlinear neutral equations and we focus on applications to partial “nonlinear” neutral differential equations. Some applications involving partial neutral differential equations are presented.

  19. Quantifying the impact of human immunodeficiency virus-1 escape from cytotoxic T-lymphocytes.

    Directory of Open Access Journals (Sweden)

    Ulrich D Kadolsky

    2010-11-01

    Full Text Available HIV-1 escape from the cytotoxic T-lymphocyte (CTL response leads to a weakening of viral control and is likely to be detrimental to the patient. To date, the impact of escape on viral load and CD4(+ T cell count has not been quantified, primarily because of sparse longitudinal data and the difficulty of separating cause and effect in cross-sectional studies. We use two independent methods to quantify the impact of HIV-1 escape from CTLs in chronic infection: mathematical modelling of escape and statistical analysis of a cross-sectional cohort. Mathematical modelling revealed a modest increase in log viral load of 0.051 copies ml(-1 per escape event. Analysis of the cross-sectional cohort revealed a significant positive association between viral load and the number of "escape events", after correcting for length of infection and rate of replication. We estimate that a single CTL escape event leads to a viral load increase of 0.11 log copies ml(-1 (95% confidence interval: 0.040-0.18, consistent with the predictions from the mathematical modelling. Overall, the number of escape events could only account for approximately 6% of the viral load variation in the cohort. Our findings indicate that although the loss of the CTL response for a single epitope results in a highly statistically significant increase in viral load, the biological impact is modest. We suggest that this small increase in viral load is explained by the small growth advantage of the variant relative to the wildtype virus. Escape from CTLs had a measurable, but unexpectedly low, impact on viral load in chronic infection.

  20. Escape of H and D from Mars' Atmosphere and the Evolution of its Crustal Water Reservoirs

    Science.gov (United States)

    Hartle, Richard E.; Einaudi, Franco (Technical Monitor)

    2001-01-01

    The evolution of water on Mars involves preferential escape of hydrogen over deuterium, producing its deuterium rich atmosphere with a D/H ratio 5.2 times that of terrestrial water. In the past decade, several estimates have been made of the magnitudes of current and ancient crustal water reservoirs on Mars that freely exchange with its atmosphere. Some of the differences in the magnitudes of the reservoirs are influenced by differences in the following basic parameters: composition of H, D, H2 and HD at the exobase; thermal history of the atmosphere; escape mechanisms; and the D/H ratio of earlier epochs as inferred from meteorites. The dominant escape mechanism used in the estimates is Jeans escape. However, the Jeans escape flux is enhanced considerably when atmospheric winds and rotation are applied at the exobase . This constraint is of particular importance because the enhancement of the D escape flux can be an order of magnitude greater than the enhancement of the H escape flux. This preferential enhancement of the D escape flux over that of H means that a great deal more H must escape (than in the case without winds and rotation) to attain the same D/H ratio in the today's atmosphere. Another new constraint on reservoir magnitudes comes from the recent interpretation of Martian meteorite data, which suggests that the D/H ratio was 2 times that of terrestrial water at the end of the heavy bombardment period (1). These two constraints together lead to larger current and ancient crustal water reservoirs. Applying Rayleigh fractionation, new estimates of the sizes of the water reservoirs are made using the above constraints along with plausible values for hydrogen and deuterium densities, temperatures, wind speeds and rotation rates at the exobase.

  1. Structure and Recognition of a Novel HIV-1 gp120-gp41 Interface Antibody that Caused MPER Exposure through Viral Escape

    Energy Technology Data Exchange (ETDEWEB)

    Wibmer, Constantinos Kurt; Gorman, Jason; Ozorowski, Gabriel; Bhiman, Jinal N.; Sheward, Daniel J.; Elliott, Debra H.; Rouelle, Julie; Smira, Ashley; Joyce, M. Gordon; Ndabambi, Nonkululeko; Druz, Aliaksandr; Asokan, Mangai; Burton, Dennis R.; Connors, Mark; Abdool Karim, Salim S.; Mascola, John R.; Robinson, James E.; Ward, Andrew B.; Williamson, Carolyn; Kwong, Peter D.; Morris, Lynn; Moore, Penny L.; Desrosiers, Ronald C.

    2017-01-11

    A comprehensive understanding of the regions on HIV-1 envelope trimers targeted by broadly neutralizing antibodies may contribute to rational design of an HIV-1 vaccine. We previously identified a participant in the CAPRISA cohort, CAP248, who developed trimer-specific antibodies capable of neutralizing 60% of heterologous viruses at three years post-infection. Here, we report the isolation by B cell culture of monoclonal antibody CAP248-2B, which targets a novel membrane proximal epitope including elements of gp120 and gp41. Despite low maximum inhibition plateaus, often below 50% inhibitory concentrations, the breadth of CAP248-2B significantly correlated with donor plasma. Site-directed mutagenesis, X-ray crystallography, and negative-stain electron microscopy 3D reconstructions revealed how CAP248-2B recognizes a cleavage-dependent epitope that includes the gp120 C terminus. While this epitope is distinct, it overlapped in parts of gp41 with the epitopes of broadly neutralizing antibodies PGT151, VRC34, 35O22, 3BC315, and 10E8. CAP248-2B has a conformationally variable paratope with an unusually long 19 amino acid light chain third complementarity determining region. Two phenylalanines at the loop apex were predicted by docking and mutagenesis data to interact with the viral membrane. Neutralization by CAP248-2B is not dependent on any single glycan proximal to its epitope, and low neutralization plateaus could not be completely explained by N- or O-linked glycosylation pathway inhibitors, furin co-transfection, or pre-incubation with soluble CD4. Viral escape from CAP248-2B involved a cluster of rare mutations in the gp120-gp41 cleavage sites. Simultaneous introduction of these mutations into heterologous viruses abrogated neutralization by CAP248-2B, but enhanced neutralization sensitivity to 35O22, 4E10, and 10E8 by 10-100-fold. Altogether, this study expands the region of the HIV-1 gp120-gp41 quaternary interface that is a target for broadly neutralizing

  2. Structure and Recognition of a Novel HIV-1 gp120-gp41 Interface Antibody that Caused MPER Exposure through Viral Escape.

    Science.gov (United States)

    Wibmer, Constantinos Kurt; Gorman, Jason; Ozorowski, Gabriel; Bhiman, Jinal N; Sheward, Daniel J; Elliott, Debra H; Rouelle, Julie; Smira, Ashley; Joyce, M Gordon; Ndabambi, Nonkululeko; Druz, Aliaksandr; Asokan, Mangai; Burton, Dennis R; Connors, Mark; Abdool Karim, Salim S; Mascola, John R; Robinson, James E; Ward, Andrew B; Williamson, Carolyn; Kwong, Peter D; Morris, Lynn; Moore, Penny L

    2017-01-01

    A comprehensive understanding of the regions on HIV-1 envelope trimers targeted by broadly neutralizing antibodies may contribute to rational design of an HIV-1 vaccine. We previously identified a participant in the CAPRISA cohort, CAP248, who developed trimer-specific antibodies capable of neutralizing 60% of heterologous viruses at three years post-infection. Here, we report the isolation by B cell culture of monoclonal antibody CAP248-2B, which targets a novel membrane proximal epitope including elements of gp120 and gp41. Despite low maximum inhibition plateaus, often below 50% inhibitory concentrations, the breadth of CAP248-2B significantly correlated with donor plasma. Site-directed mutagenesis, X-ray crystallography, and negative-stain electron microscopy 3D reconstructions revealed how CAP248-2B recognizes a cleavage-dependent epitope that includes the gp120 C terminus. While this epitope is distinct, it overlapped in parts of gp41 with the epitopes of broadly neutralizing antibodies PGT151, VRC34, 35O22, 3BC315, and 10E8. CAP248-2B has a conformationally variable paratope with an unusually long 19 amino acid light chain third complementarity determining region. Two phenylalanines at the loop apex were predicted by docking and mutagenesis data to interact with the viral membrane. Neutralization by CAP248-2B is not dependent on any single glycan proximal to its epitope, and low neutralization plateaus could not be completely explained by N- or O-linked glycosylation pathway inhibitors, furin co-transfection, or pre-incubation with soluble CD4. Viral escape from CAP248-2B involved a cluster of rare mutations in the gp120-gp41 cleavage sites. Simultaneous introduction of these mutations into heterologous viruses abrogated neutralization by CAP248-2B, but enhanced neutralization sensitivity to 35O22, 4E10, and 10E8 by 10-100-fold. Altogether, this study expands the region of the HIV-1 gp120-gp41 quaternary interface that is a target for broadly neutralizing

  3. A New Method to Monitor the Primary Neutral Integrity in Multi-Grounded Neutral Systems

    Directory of Open Access Journals (Sweden)

    Xiangmin Xie

    2017-03-01

    Full Text Available In the three-phase four-wire system, there are usually multiple grounding points in the primary neutral line due to safety and economic considerations. The rising “neutral to earth voltage (NEV” caused by a broken primary neutral can threaten the safety of nearby facilities and humans; therefore, the integrity of the primary neutral conductor is of vital importance for the multi-grounded neutral (MGN system. In this paper, a new passive method is proposed to monitor the integrity of the primary neutral line in the MGN system. The method is based on the measured voltage and current data at the service transformer, and there is no need to install any signal generators. Therefore, it causes no disturbance to the utility and customer. In the paper, the equivalent analysis circuit is established and a new parameter is proposed to reflect the neutral condition. The value of the parameter is estimated based on the measured data, and then, the equivalent impedance of the primary neutral groundings can be obtained. On the other hand, the impedance value for the primary neutral under normal operating conditions can be estimated based on the derived analytical formulas. By comparing the monitored primary neutral impedance with its normal value, the broken neutral condition in the primary system can be detected. Different primary neutral broken cases are analyzed in the paper based on the Monte Carlo simulation. The results indicate that the integrity condition in the primary neutral can be accurately monitored by the proposed method.

  4. Liberal Neutrality : Constructivist, not foundationalist

    Directory of Open Access Journals (Sweden)

    Lendell Horne

    2009-06-01

    Full Text Available In defending the principle of neutrality, liberals have often appealed to a more general moral principle that forbids coercing persons in the name of reasons those persons themselves cannot reasonably be expected to share. Yet liberals have struggled to articulate a non-arbitrary, non-dogmatic distinction between the reasons that persons can reasonably be expected to share and those they cannot. The reason for this, I argue, is that what it means to “share a reason” is itself obscure. In this paper I articulate two different conceptions of what it is to share a reason; I call these conceptions “foundationalist” and “constructivist.” On the foundationalist view, two people “share” a reason just in the sense that the same reason applies to each of them independently. On this view, I argue, debates about the reasons we share collapse into debates about the reasons we have, moving us no closer to an adequate defense of neutrality. On the constructivist view, by contrast, “sharing reasons” is understood as a kind of activity, and the reasons we must share are just those reasons that make this activity possible. I argue that the constructivist conception of sharing reasons yields a better defense of the principle of neutrality. À travers leur défense du principe de neutralité, les libéraux ont souvent interpellé un principe moral plus général qui interdit de contraindre des personnes pour des raisons dont on ne peut raisonnablement attendre que ces personnes elles-mêmes les partagent. Les libéraux éprouvent cependant de la difficulté à articuler une distinction non-arbitraire et non-dogmatique entre les raisons dont on peut raisonnablement attendre que les personnes les partagent et celles dont on ne le peut pas. Je soutiens dans cet article que cette difficulté provient du fait que «partager une raison » est une notion obscure. Pour illustrer cela, je me pencherai sur deux conceptions distinctes de ce que veut dire

  5. A new model for estimation of the consequences of chemical hazards - ESCAPE for Windows; Uusi malli kemikaalionnettomuuksien seurausten arvioimiseen - ESCAPE for Windows

    Energy Technology Data Exchange (ETDEWEB)

    Nikmo, J.; Kukkonen, J.; Riikonen, K. [The Finnish Meteorological Institute, Helsinki (Finland)

    1999-07-01

    By the new computerized model 'ESCAPE for Windows' it is possible to estimate the emissions hazardous substance, the spreading and the impacts of them during chemical accidents. The software can best be used e.g. for rescue service if authorities and the industry, in inspections of industrial plants and post-accident impact analyses. The software has 100 users outside the Meteorological Institute. The model consists of a collection of flow and spreading models. The input data needed consist of the weather and emissions data. The more detailed information on the ESCAPE- model can be found in the English WWW-home page of the model in address http://www.fmi.fi/ENG/ILA/escape.html.

  6. Driving citations and aggressive behavior.

    Science.gov (United States)

    Sansone, Randy A; Leung, Justin S; Wiederman, Michael W

    2012-01-01

    Anger and driving have been examined in a number of studies of aggressive drivers and in drivers with road rage using various psychological and environmental study variables. However, we are not aware of any study that has examined the number of driving citations (an indication of problematic driving) and various forms of anger not related to driving. Using a cross-sectional approach in a consecutive sample of 331 respondents (68% female), we surveyed participants about the number of past driving citations, not necessarily convictions, and 21 aggressive behaviors using the Aggressive Behavior Questionnaire. The number of driving citations demonstrated a statistically significant correlation with the number of aggressive behaviors in the 21-item Aggressive Behavior Questionnaire. There were no differences between men and women. As for specific aggressive behaviors, the number of driving citations was statistically significantly related to punching a wall when angry, causing and getting into a bar fight, getting into fistfights (not in a bar), causing someone to have an accident, and intentionally running someone off the road. The number of driving citations, an indication of problematic driving, appears to be related to generally aggressive behavior. Findings indicate that if aggression plays a role in problematic driving, it is likely not limited to the road.

  7. Novel neutralized-beam intense neutron source for fusion technology development

    International Nuclear Information System (INIS)

    Osher, J.E.; Perkins, L.J.

    1983-01-01

    We describe a neutralized-beam intense neutron source (NBINS) as a relevant application of fusion technology for the type of high-current ion sources and neutral beamlines now being developed for heating and fueling of magnetic-fusion-energy confinement systems. This near-term application would support parallel development of highly reliable steady-state higher-voltage neutral D 0 and T 0 beams and provide a relatively inexpensive source of fusion neutrons for materials testing at up to reactor-like wall conditions. Beam-target examples described incude a 50-A mixed D-T total (ions plus neutrals) space-charge-neutralized beam at 120 keV incident on a liquid Li drive-in target, or a 50-A T 0 + T + space-charge-neutralized beam incident on either a LiD or gas D 2 target with calculated 14-MeV neutron yields of 2 x 10 15 /s, 7 x 10 15 /s, or 1.6 x 10 16 /s, respectively. The severe local heat loading on the target surface is expected to limit the allowed beam focus and minimum target size to greater than or equal to 25 cm 2

  8. Driving without a GPS

    DEFF Research Database (Denmark)

    Lauridsen, Karen M.

    in the best way possible; and that the differences in their knowledge systems is acknowledged and used as an asset in these international programmes. With these factors in place, on the other hand, programmes with international faculty and diverse student audiences in which this diversity is exploited...... as students as well as the lecturers themselves represent a diverse range of first languages, cultures and knowledge systems; at the same time, the teaching and learning must reach at least the same high quality standards as in more traditional mono-lingual and mono-cultural settings. For a lecturer...... in an appropriate way, may have a considerable added value that positively impacts on the knowledge, skills and competences developed by their graduates. However, lecturers often feel at a loss because they are not sure how to do this and teaching becomes like driving in unknown territory without a GPS. Based...

  9. Control rod drives

    International Nuclear Information System (INIS)

    Kono, Nobuaki.

    1987-01-01

    Purpose: To remove movable portion and improve the reliability by the direct control to coil. Constitution: Coils are disposed vertically at a predetermined interval to the outside of a control rod drive guide tube and each of the coils is adapted to be directly controlled. The coils are arranged at such an interval that a plunger laps over the vertically adjacent coils. In the case of moving the plunger upwardly, a coil just above the coil that attract the plunger is energized while the coil attracting the plunger so far is denergized. Then, the plunger is pulled up to an aimed position by repeating the procedures. In the case of moving the plunger downwardly, the procedures are conducted in the manner opposite to the above. (Kawakami, Y.)

  10. TORE SUPRA neutral injection system

    International Nuclear Information System (INIS)

    Bayetti, P.; Becherer, R.; Bottiglioni, F.; Jacquot, C.; Jequier, F.; Fumelli, M.; Lotte, P.; Pamela, J.; Sledziewski, Z.

    1989-01-01

    The Neutral Beam Injection on TS consists of three boxes, each housing two injectors. Each of them is designed to accelerate 40 A at 100 kV in D 2 ar 40A at 80 kV in H 2 , in shots of 30 s. The power on the plasma is expected to be 7.5 MW (full energy) and 9 MW (total) for the D-beams; 2.5 MW and 3.8 MW for H-beams. This for a species mix of 0.85 19 m -2 and a transmission efficiency of 0.7. Four injectors are in co and two through another one, and they are tilted of 20 deg from the radial direction. Injectors are designed for the energy recovery of the full energy ions. A prototype line, operated in 1987-88, has given the imput for the demensioning of the present system.First injectors are expected to be operational by the end of 1988. The present contribution describes the injection boxes, injection line, magnetic shielding, electrical circuity and power supplies, control and data acquisition systems, and the Fast Interlock Safety System (FISS). 7 refs.; 6 figs

  11. Breakdown studies for neutral injectors

    International Nuclear Information System (INIS)

    Bottiglioni, F.; Bussac, J.P.

    1981-01-01

    Reliable operation of high energy neutral injectors is challenged by the voltage hold-off capability of the extraction systems. The high voltage behavior of a gap depends not only on a large number of macroscopic parameters, e.g. the electrodes material, geometry, separation, and residual gas pressure, but also upon dimly defined and badly controlled microscopic electric properties such as electrodes surface conditions, which are in turn affected by the conditioning procedures and by the operational history of the gap. In fact, it is merely due to the microscopic surface conditions of electrodes, especially cathodes, that for most favorable regimes, macroscopic breakdown fields are two orders of magnitude lower than what can be expected from the field emission theory (E greater than or equal to 3 10 9 V/m). At FAR, experimental data on the voltage hold-off problems are obtained in a large injector (Megawatt Beam Line - MWBL) and in L.E.O., a smaller but more flexible facility where single beam studies will be made, up to 160 keV. Some results are described

  12. Do emotions drive psychosis?

    Directory of Open Access Journals (Sweden)

    João G. Ribeiro

    2012-12-01

    Full Text Available Introduction: How important is the emotional life of persons who manifest psychotic symptoms? Aims: The aim of this paper is to review evidence on a causal role for emotions in psychotic processes. Methods: Selective review of literature on affective symptoms in psychoses, on emotions in the production of psychotic symptoms and on dopaminergic models of psychosis. Results: Affective symptoms are relevant across psychoses. Persons with schizophrenia have high levels of emotional reactivity and the intensification of negative affects not only is associated with but also precedes the intensification of psychotic symptoms, which is evidence that negative emotions drive the course of psychotic symptoms. Negative self‑representations are central in psychotic processes and can be the link between negative emotions and psychosis. Evidence favours the notion that persecutory delusions are consistent with negative affects and self‑representations, while grandiose delusions are consistent with a defensive amplification of positive affects and self‑representations. Shame has been proposed as the core emotional experience of psychosis, one in which the self becomes vulnerable to the external world, which is consistent with persecutory experiences. Assaults on the self, under the form of hostility in the family environment and society, are strong predictors of relapse and development of schizophrenia. Assaults on the self which induce social defeat are also strong stimulants of mesolimbic dopaminergic pathways, whose hyperactivity is associated with acute psychotic episodes and the experience of “aberrant salience”, put forward as a dopaminergic model of psychosis. Conclusions: The “defeat of the self” emerges as a central link that binds the experience of negative emotions to the expression of psychotic symptoms and its psychological and neurobiological correlates. The hypothesis gains support that the emotions related to that defeat control

  13. Photoproduction of neutral pions off protons

    NARCIS (Netherlands)

    Crede, V.; Sparks, N.; Wilson, A.; Anisovich, A. V.; Bacelar, J. C. S.; Bantes, R.; Bartholomy, O.; Bayadilov, D.; Beck, R.; Beloglazov, Y. A.; Castelijns, R.; Dutz, H.; Elsner, D.; Ewald, R.; Frommberger, F.; Funke, Chr; Gregor, R.; Gridnev, A.; Gutz, E.; Hillert, W.; Hoffmeister, P.; Jaegle, I.; Junkersfeld, J.; Kalinowsky, H.; Kammer, S.; Klein, Frank; Klein, Friedrich; Klempt, E.; Kotulla, M.; Krusche, B.; Löhner, H.; Lopatin, I. V.; Lugert, S.; Menze, D.; Mertens, T.; Messchendorp, J. G.; Metag, V.; Nanova, M.; Nikonov, V. A.; Novinski, D.; Novotny, R.; Ostrick, M.; Pant, L. M.; van Pee, H.; Pfeiffer, M.; Roy, A.; Sarantsev, A. V.; Schadmand, S.; Schmidt, C.; Schmieden, H.; Schoch, B.; Shende, S.; Sokhoyan, V.; Suele, A.; Sumachev, V. V.; Szczepanek, T.; Thoma, U.; Trnka, D.; Varma, R.; Walther, D.; Wendel, Ch

    2011-01-01

    Photoproduction of neutral pions has been studied with the CBELSA/TAPS detector in the reaction gamma p -> p pi(0) for photon energies between 0.85 and 2.50 GeV. The pi(0) mesons are observed in their dominant neutral decay mode: pi(0) -> gamma gamma. For the first time, the differential cross

  14. 32 CFR 644.323 - Neutral language.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 4 2010-07-01 2010-07-01 true Neutral language. 644.323 Section 644.323 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY (CONTINUED) REAL PROPERTY REAL ESTATE HANDBOOK Disposal § 644.323 Neutral language. Wherever the words “man”, “men”, or their related...

  15. Targets for high power neutral beams

    International Nuclear Information System (INIS)

    Kim, J.

    1980-01-01

    Stopping high-power, long-pulse beams is fast becoming an engineering challenge, particularly in neutral beam injectors for heating magnetically confined plasmas. A brief review of neutral beam target technology is presented along with heat transfer calculations for some selected target designs

  16. Auditors' Professional Skepticism: Neutrality versus Presumptive Doubt

    NARCIS (Netherlands)

    Groot, T.L.C.M.; Quadackers, L.M.; Wright, A.

    2014-01-01

    Although skepticism is widely viewed as essential to audit quality, there is a debate about what form is optimal. The two prevailing perspectives that have surfaced are "neutrality" and "presumptive doubt." With neutrality, auditors neither believe nor disbelieve client management. With presumptive

  17. Neutralization of wastewater from nitrite passivation

    International Nuclear Information System (INIS)

    Pawlowski, L.; Mientki, B.; Wasag, H.

    1982-01-01

    A method for neutralization of wastewater formed in nitrite passivation has been presented. The method consists of introducing urea into wastewater and acidifying it with sulphuric acid. Wastewater is neutralized with lime. After clarification, wastewater can be drained outside the plant

  18. The Framing of Network Neutrality Governance

    DEFF Research Database (Denmark)

    Perry, James

    The neutrality of the internet with regard to applications (e.g. search, social networking, email, to mention only three) has been central to innovation and growth in the knowledge-economy over the past two decades. Until recently, neutrality was built into the internet's design via its core stan...

  19. The case for ecological neutral theory

    NARCIS (Netherlands)

    Rosindell, James; Hubbell, Stephen P.; He, Fangliang; Harmon, Luke J.; Etienne, Rampal S.

    Ecological neutral theory has elicited strong opinions in recent years. Here, we review these opinions and strip away some unfortunate problems with semantics to reveal three major underlying questions. Only one of these relates to neutral theory and the importance of ecological drift, whereas the

  20. CLIC Drive Beam Phase Stabilisation

    CERN Document Server

    Gerbershagen, Alexander; Schulte, Daniel

    The thesis presents phase stability studies for the Compact Linear Collider (CLIC) and focuses in particular on CLIC Drive Beam longitudinal phase stabilisation. This topic constitutes one of the main feasibility challenges for CLIC construction and is an essential component of the current CLIC stabilisation campaign. The studies are divided into two large interrelated sections: the simulation studies for the CLIC Drive Beam stability, and measurements, data analysis and simulations of the CLIC Test Facility (CTF3) Drive Beam phase errors. A dedicated software tool has been developed for a step-by-step analysis of the error propagation through the CLIC Drive Beam. It uses realistic RF potential and beam loading amplitude functions for the Drive and Main Beam accelerating structures, complete models of the recombination scheme and compressor chicane as well as of further CLIC Drive Beam modules. The tool has been tested extensively and its functionality has been verified. The phase error propagation at CLIC h...

  1. A neutral sampling formula for multiple samples and an `exact' test of neutrality

    NARCIS (Netherlands)

    Etienne, R.S.

    2007-01-01

    As the utility of the neutral theory of biodiversity is increasingly being recognized, there is also an increasing need for proper tools to evaluate the relative importance of neutral processes (dispersal limitation and stochasticity). One of the key features of neutral theory is its close link to

  2. A neutral sampling formula for multiple samples and an 'exact' test of neutrality

    NARCIS (Netherlands)

    Etienne, Rampal S.

    As the utility of the neutral theory of biodiversity is increasingly being recognized, there is also an increasing need for proper tools to evaluate the relative importance of neutral processes (dispersal limitation and stochasticity). One of the key features of neutral theory is its close link to

  3. Plasma particle sources due to interactions with neutrals in a turbulent scrape-off layer of a toroidally confined plasma

    DEFF Research Database (Denmark)

    Thrysøe, Alexander Simon; Løiten, M.; Madsen, J.

    2018-01-01

    The conditions in the edge and scrape-off layer (SOL) of magnetically confined plasmas determine the overall performance of the device, and it is of great importance to study and understand the mechanics that drive transport in those regions. If a significant amount of neutral molecules and atoms...

  4. Power supply for the LBL 40 keV neutral beam source

    International Nuclear Information System (INIS)

    Baker, W.R.; Fitzgerald, M.L.; Honey, V.J.

    1975-11-01

    A 20 keV, 50 Amp, 10 millisec pulse D 0 Neutral Beam Source at the Lawrence Berkeley Laboratory that serves as the prototype for 12 similar sources now in operation on the 2XIIB Mirror Machine at the Lawrence Livermore Laboratory has been recently upgraded to operate at 40 keV. The system of electronically regulated and controlled power supplies that drive the Source is described

  5. Neutral beam injection system design for KSTAR tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Choi, B.H.; Lee, K.W.; Chung, K.S.; Oh, B.H.; Cho, Y.S.; Bae, Y.D.; Han, J.M. [Korea Atomic Energy Research Institute, Taejon (Korea)

    1998-06-01

    The NBI system for KSTAR (Korean Superconducting Tokamak Advanced Research) has been designed based on conventional positive ion beam technology. One beam line consists of three ion sources, three neutralizers, one bending magnet, and one drift tube. This system will deliver 8 MW deuterium beam to KSTAR plasma in normal operation to support the advanced experiments on heating, current drive and profile control. The key technical issues in this design were high power ion source(120 kV, 65 A), long pulse operation (300 seconds; world record is 30 sec), and beam rotation from vertical to horizontal direction. The suggested important R and D points on ion source and beam line components are also included. (author). 7 refs., 27 figs., 1 tab.

  6. Escape and Capture from Deep Gravity Wells (Earth, Moon, Planets) Using Low Thrust Propulsion Systems

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA missions are increasingly looking to use low thrust propulsion to capture into planetary orbits and/or lunar orbits, and to escape from low earth orbit. This...

  7. Escape windows to improve the size selectivity in the Baltic cod trawl fishery

    DEFF Research Database (Denmark)

    Madsen, Niels; Holst, René; Foldager, L.

    2002-01-01

    . The history of the use of escape windows in the Baltic Sea cod fishery is reviewed. The present escape windows do not function optimally. The objective of this new experiment was to compare an improved design of escape window, which is placed in the upper panel, with that of standard codend. Three standard......A rapid decrease of the stock of Baltic cod (Gadus morhua) has provided the incentive to improve the size selectivity in the trawl fishery. Use of escape windows is permitted in the legislation to give means of improving the size selectivity of cod as an alternative to a traditional standard codend...... tool to improve the size selectivity in the Baltic cod fishery is discussed. (C) 2002 Elsevier Science B.V. All rights reserved....

  8. Unsteady motion: escape jumps in planktonic copepods, their kinematics and energetics

    DEFF Research Database (Denmark)

    Kiørboe, Thomas; Andersen, Anders Peter; Langlois, Vincent J.

    2010-01-01

    estimate the force and power output needed to accelerate and overcome drag. Both are very high compared with those of other organisms, as are the escape velocities in comparison to startle velocities of other aquatic animals. Thus, the maximum weight-specific force, which for muscle motors of other animals...... has been found to be near constant at 57 N (kg muscle)−1, is more than an order of magnitude higher for the escaping copepods. We argue that this is feasible because most copepods have different systems for steady propulsion (feeding appendages) and intensive escapes (swimming legs), with the muscular...... arrangement of the latter probably adapted for high force production during short-lasting bursts. The resulting escape velocities scale with body length to power 0.65, different from the size-scaling of both similar sized and larger animals moving at constant velocity, but similar to that found for startle...

  9. 78 FR 54585 - Safety Zone; Escape to Miami Triathlon, Biscayne Bay, Miami, FL

    Science.gov (United States)

    2013-09-05

    ... Road Sports and Entertainment Group are sponsoring the Publix Escape to Miami Triathlon. The event will... direct effect on the States, on the relationship between the national government and the States, or on... Coordination with Indian Tribal Governments, [[Page 54587

  10. Inward contaminant leakage tests of the S-Tron Corporation emergency escape breathing device.

    Science.gov (United States)

    1992-04-01

    At the request of S-Tron Corporation, to support their contract with the U.S. Navy, performance tests of the Emergency Escape Breathing Device (EEBD) were conducted in the Environmental Physiology Research Section contaminant leakage chamber. Sulfur ...

  11. Common-mode Voltage Reduction in a Motor Drive System with a Power Factor Correction

    DEFF Research Database (Denmark)

    Adabi, J.; Boora, A.A.; Zare, F.

    2012-01-01

    Common-mode voltage generated by a power converter in combination with parasitic capacitive couplings is a potential source of shaft voltage in an AC motor drive system. In this study, a three-phase motor drive system supplied with a single-phase AC-DC diode rectifier is investigated in order...... to reduce shaft voltage in a three-phase AC motor drive system. In this topology, the AC-DC diode rectifier influences the common-mode voltage generated by the inverter because the placement of the neutral point is changing in different rectifier circuit states. A pulse width modulation technique...

  12. The Drive-Wise Project: Driving Simulator Training increases real driving performance in healthy older drivers

    Directory of Open Access Journals (Sweden)

    Gianclaudio eCasutt

    2014-05-01

    Full Text Available Background: Age-related cognitive decline is often associated with unsafe driving behavior. We hypothesized that 10 active training sessions in a driving simulator increase cognitive and on-road driving performance. In addition, driving simulator training should outperform cognitive training.Methods: Ninety-one healthy active drivers (62 – 87 years were randomly assigned to either (1 a driving simulator training group, (2 an attention training group (vigilance and selective attention, or (3 a control group. The main outcome variables were on-road driving and cognitive performance. Seventy-seven participants (85% completed the training and were included in the analyses. Training gains were analyzed using a multiple regression analysis with planned comparisons.Results: The driving simulator training group showed an improvement in on-road driving performance compared to the attention training group. In addition, both training groups increased cognitive performance compared to the control group. Conclusion: Driving simulator training offers the potential to enhance driving skills in older drivers. Compared to the attention training, the simulator training seems to be a more powerful program for increasing older drivers’ safety on the road.

  13. Neutral-beam-heating applications and development

    International Nuclear Information System (INIS)

    Menon, M.M.

    1981-01-01

    The technique of heating the plasma in magnetically confined fusion devices by the injection of intense beams of neutral atoms is described. The basic principles governing the physics of neutral beam heating and considerations involved in determining the injection energy, power, and pulse length required for a fusion reactor are discussed. The pertinent experimental results from various fusion devices are surveyed to illustrate the efficacy of this technique. The second part of the paper is devoted to the technology of producing the neutral beams. A state-of-the-art account o the development of neutral injectors is presented, and the prospects for utilizing neutral injection to heat the plasma in a fusion reactor are examined

  14. Tax Neutrality on International Capital Investments

    Directory of Open Access Journals (Sweden)

    Gizem KAPUCU

    2017-07-01

    Full Text Available The tax policies which states follow with regard to developing technology and capital investments with raising mobility due to globalism are need to be discussed in its legal basis. The principle of tax neutrality has the aim of being legal foundation for these policies. According to this, the neutrality principle in taxation of international capital investments is provided with two measures, namely; not effecting the investment decision and not discriminate between investments. In this paper, initially focused on the conceptual framework and the foundations of the tax neutrality principle and later capital export neutrality and capital import neutrality are considered and explained with regard to international capital movements. Moreover, conformity and diversion to the principle of the current situation and regulations in OECD, EU and Turkey are examined.

  15. Motor Integrated Variable Speed Drives

    DEFF Research Database (Denmark)

    Singh, Yash Veer

    A new trend in the variable speed drives (VSDs) is to develop fully integrated systems, which lead to low-cost products with shorter design cycles. Motor Integrated design of VSDs will reduce cable length to connect drive with machine windings and installation time for end user. The electric drives...... so it can fit inside the motor housing. Weight and volume of a filter inductor has to come down drastically to make it a suitable power converter for motor integrated variable speed drives. Introduction of active power electronic switches can ensure very high performance and small size...

  16. Inhibition of chaotic escape from a potential well using small parametric modulations

    International Nuclear Information System (INIS)

    Chacon, R.; Balibrea, F.; Lopez, M.A.

    1996-01-01

    It is shown theoretically for the first time that, depending on its period, amplitude, and initial phase, a periodic parametric modulation can suppress a chaotic escape from a potential well. The instance of the Helmholtz oscillator is used to demonstrate, by means of Melnikov close-quote s method, that parametric modulations of the linear or quadratic potential terms inhibit chaotic escape when certain resonance conditions are met. copyright 1996 American Institute of Physics

  17. Outlet strut fracture and leaflet escape of Bjork-Shiley convexo-concave valve.

    Science.gov (United States)

    Uchino, Gaku; Yoshida, Hideo; Sakoda, Naoya; Hattori, Shigeru; Kawabata, Takuya; Saiki, Munehiro; Fujita, Yasufumi; Yunoki, Keiji; Hisamochi, Kunikazu; Mine, Yoshinari

    2017-06-01

    Prosthetic valve fracture is a serious complication and may arise in patient post-valve replacement. We experienced an outlet strut fracture and leaflet escape of a Bjork-Shiley convexo-concave valve. We performed an emergency redo mitral valve replacement and successfully retrieved the fractured strut and escaped leaflet from superficial femoral artery and the abdominal aorta. The patient showed an uneventful postoperative recovery.

  18. The relationship between migration and development in the ESCAP region.

    Science.gov (United States)

    Skeldon, R

    1991-01-01

    The relationship between migration and development in the ESCAP region including southeast and south Asian countries and the Pacific island of Fiji, Papua New Guinea, Vanuatu, Kiribati, Samoa, and the Solomon Islands is discussed in terms of mobility transition and origin and destination factors. The changing patterns of mobility in Asia are further delineated in the discussion of internal movements and international movement. Emigration in the smaller countries of the Pacific are treated separately. Future predictions are that the Asia Pacific region will experience continued fertility decline and stabilization of low rates over the next 20 years. The declines will result in slow labor force growth, and increased demand for labor in traditional core and neocore countries as defined and presented in table form by Friedman will be heightened. International movements are likely to increase in large urban areas within destination countries. Tokyo and Singapore are the principal cities in Asia. Tokyo by restrictive government policy has limited immigration, but future labor shortages of unskilled labor from southeast Asia and China are expected. Singapore is already dependent on foreign labor by 10%. Current labor shortages have led to the creation of a growth triangle between Singapore, Indonesia, and Malaysia. Other cities expected to emerge as primary cities in international regional complexes with spillover into the hinterlands include the Hong Kong, Guangzhou, and Macau triangle in the Pearl River delta, Taipei and Seoul, and possibly Kuala Lumpur. Internal migration is expected to increase in the capital cities of Bangkok, Manila,j and centers such as Shanghai, Beijing, and other large cities of southeast Asia. These cities will be linked through the flows of skilled international migrants, which began in the 1960s and is expected to become a future major flow. Recreational and resource niches will be left in much of the Pacific, the Himalayan Kingdoms, and

  19. Both species sorting and neutral processes drive assembly of bacterial communities in aquatic microcosms

    NARCIS (Netherlands)

    Lee, Jack E.; Buckley, Hannah L.; Etienne, Rampal S.; Lear, Gavin

    2013-01-01

    A focus of ecology is to determine drivers of community assembly. Here, we investigate effects of immigration and species sorting (environmental selection) on structuring aquatic bacterial communities in both colonised and previously uncolonised environments. We used nonsterilised and presterilised

  20. Enhancing usability of augmented-reality-based mobile escape guidelines for radioactive accidents

    International Nuclear Information System (INIS)

    Tsai, Ming-Kuan; Yau, Nie-Jia

    2013-01-01

    When radioactive accidents occur, modern tools in information technology for emergency response are good solutions to reduce the impact. Since few information-technology-based applications were developed for people during radioactive accidents, a previous study (Tsai et al., 2012) proposed augmented-reality-based mobile escape guidelines. However, because of the lack of transparent escape routes and indoor escape guidelines, the usability of the guidelines is limited. Therefore, this study introduces route planning and mobile three-dimensional (3D) graphics techniques to address the identified problems. The proposed approach could correctly present the geographical relationship from user locations to the anticipated shelters, and quickly show the floor-plan drawings as users are in the buildings. Based on the testing results, in contrast to the previous study, this study offered better escape routes, when the participants performed self-evacuation in outdoor and indoor environments. Overall, this study is not only a useful reference for similar studies, but also a beneficial tool for emergency response during radioactive accidents. -- Highlights: ► Enhancing the efficiency when people escape from radioactive accidents. ► The spatial relationship is transparently displayed in real time. ► In contrast to a previous study, this study offers better escape guidelines

  1. Scaling invariance for the escape of particles from a periodically corrugated waveguide

    Energy Technology Data Exchange (ETDEWEB)

    Leonel, Edson D., E-mail: edleonel@rc.unesp.br [Departamento de Estatística, Matemática Aplicada e Computação, UNESP – Univ Estadual Paulista, Av. 24A, 1515, CEP 13506-900, Rio Claro, SP (Brazil); Costa, Diogo R. da [Departamento de Estatística, Matemática Aplicada e Computação, UNESP – Univ Estadual Paulista, Av. 24A, 1515, CEP 13506-900, Rio Claro, SP (Brazil); Instituto de Física, Univ São Paulo, Rua do Matão, Cidade Universitária, CEP 05314-970, São Paulo, SP (Brazil); Dettmann, Carl P. [School of Mathematics, University of Bristol, Bristol BS8 1TW (United Kingdom)

    2012-01-09

    The escape dynamics of a classical light ray inside a corrugated waveguide is characterised by the use of scaling arguments. The model is described via a two-dimensional nonlinear and area preserving mapping. The phase space of the mapping contains a set of periodic islands surrounded by a large chaotic sea that is confined by a set of invariant tori. When a hole is introduced in the chaotic sea, letting the ray escape, the histogram of frequency of the number of escaping particles exhibits rapid growth, reaching a maximum value at n{sub p} and later decaying asymptotically to zero. The behaviour of the histogram of escape frequency is characterised using scaling arguments. The scaling formalism is widely applicable to critical phenomena and useful in characterisation of phase transitions, including transitions from limited to unlimited energy growth in two-dimensional time varying billiard problems. -- Highlights: ► Escape of light ray inside a corrugated waveguide ► Two-dimensional nonlinear and area preserving mapping ► Scaling for escaping particles.

  2. Effects of Serotonergic and Opioidergic Drugs on Escape Behaviors and Social Status of Male Crickets

    Science.gov (United States)

    Dyakonova, V. E.; Schürmann, F.-W.; Sakharov, D. A.

    We examined the effects of selective serotonin depletion and opioid ligands on social rank and related escape behavior of the cricket Gryllus bimaculatus. Establishment of social rank in a pair of males affected their escape reactions. Losers showed a lower and dominants a higher percentage of jumps in response to tactile cercal stimulation than before a fight. The serotonin-depleting drug α-methyltryptophan (AMTP) caused an activation of the escape reactivity in socially naive crickets. AMTP-treated animals also showed a lower ability to become dominants. With an initial 51.6+/-3.6% of wins in the AMTP group, the percentage decreased to 26+/-1.6% on day 5 after injection. The opiate receptor antagonist naloxone affected fight and escape similarly as AMTP. In contrast to naloxone, the opioid agonist [d-Ala2, N-Me-Phe4, Gly5-ol]-enkephalin decreased escape responsiveness to cercal stimulation in naive and subordinate crickets. We suggest that serotonergic and opioid systems are involved in the dominance induced depression of escape behavior.

  3. An approximate analytic model of a star cluster with potential escapers

    Science.gov (United States)

    Daniel, Kathryne J.; Heggie, Douglas C.; Varri, Anna Lisa

    2017-06-01

    In the context of a star cluster moving on a circular galactic orbit, a 'potential escaper' is a cluster star that has orbital energy greater than the escape energy, and yet is confined within the Jacobi radius of the stellar system. On the other hand, analytic models of stellar clusters typically have a truncation energy equal to the cluster escape energy, and therefore explicitly exclude these energetically unbound stars. Starting from the landmark analysis performed by Hénon of periodic orbits of the circular Hill equations, we present a numerical exploration of the population of 'non-escapers', defined here as those stars that remain within two Jacobi radii for several galactic periods, with energy above the escape energy. We show that they can be characterized by the Jacobi integral and two further approximate integrals, which are based on perturbation theory and ideas drawn from Lidov-Kozai theory. Finally, we use these results to construct an approximate analytic model that includes a phase-space description of a population resembling that of potential escapers, in addition to the usual bound population.

  4. Scaling invariance for the escape of particles from a periodically corrugated waveguide

    International Nuclear Information System (INIS)

    Leonel, Edson D.; Costa, Diogo R. da; Dettmann, Carl P.

    2012-01-01

    The escape dynamics of a classical light ray inside a corrugated waveguide is characterised by the use of scaling arguments. The model is described via a two-dimensional nonlinear and area preserving mapping. The phase space of the mapping contains a set of periodic islands surrounded by a large chaotic sea that is confined by a set of invariant tori. When a hole is introduced in the chaotic sea, letting the ray escape, the histogram of frequency of the number of escaping particles exhibits rapid growth, reaching a maximum value at n p and later decaying asymptotically to zero. The behaviour of the histogram of escape frequency is characterised using scaling arguments. The scaling formalism is widely applicable to critical phenomena and useful in characterisation of phase transitions, including transitions from limited to unlimited energy growth in two-dimensional time varying billiard problems. -- Highlights: ► Escape of light ray inside a corrugated waveguide ► Two-dimensional nonlinear and area preserving mapping ► Scaling for escaping particles.

  5. Lobelia siphilitica plants that escape herbivory in time also have reduced latex production.

    Directory of Open Access Journals (Sweden)

    Amy L Parachnowitsch

    Full Text Available Flowering phenology is an important determinant of a plant's reproductive success. Both assortative mating and niche construction can result in the evolution of correlations between phenology and other reproductive, functional, and life history traits. Correlations between phenology and herbivore defence traits are particularly likely because the timing of flowering can allow a plant to escape herbivory. To test whether herbivore escape and defence are correlated, we estimated phenotypic and genetic correlations between flowering phenology and latex production in greenhouse-grown Lobelia siphilitica L. (Lobeliaceae. Lobelia siphilitica plants that flower later escape herbivory by a specialist pre-dispersal seed predator, and thus should invest fewer resources in defence. Consistent with this prediction, we found that later flowering was phenotypically and genetically correlated with reduced latex production. To test whether herbivore escape and latex production were costly, we also measured four fitness correlates. Flowering phenology was negatively genetically correlated with three out of four fitness estimates, suggesting that herbivore escape can be costly. In contrast, we did not find evidence for costs of latex production. Generally, our results suggest that herbivore escape and defence traits will not evolve independently in L. siphilitica.

  6. Lobelia siphilitica Plants That Escape Herbivory in Time Also Have Reduced Latex Production

    Science.gov (United States)

    Parachnowitsch, Amy L.; Caruso, Christina M.; Campbell, Stuart A.; Kessler, André

    2012-01-01

    Flowering phenology is an important determinant of a plant’s reproductive success. Both assortative mating and niche construction can result in the evolution of correlations between phenology and other reproductive, functional, and life history traits. Correlations between phenology and herbivore defence traits are particularly likely because the timing of flowering can allow a plant to escape herbivory. To test whether herbivore escape and defence are correlated, we estimated phenotypic and genetic correlations between flowering phenology and latex production in greenhouse-grown Lobelia siphilitica L. (Lobeliaceae). Lobelia siphilitica plants that flower later escape herbivory by a specialist pre-dispersal seed predator, and thus should invest fewer resources in defence. Consistent with this prediction, we found that later flowering was phenotypically and genetically correlated with reduced latex production. To test whether herbivore escape and latex production were costly, we also measured four fitness correlates. Flowering phenology was negatively genetically correlated with three out of four fitness estimates, suggesting that herbivore escape can be costly. In contrast, we did not find evidence for costs of latex production. Generally, our results suggest that herbivore escape and defence traits will not evolve independently in L. siphilitica. PMID:22662205

  7. Heat-induced symmetry breaking in ant (Hymenoptera: Formicidae) escape behavior.

    Science.gov (United States)

    Chung, Yuan-Kai; Lin, Chung-Chi

    2017-01-01

    The collective egress of social insects is important in dangerous situations such as natural disasters or enemy attacks. Some studies have described the phenomenon of symmetry breaking in ants, with two exits induced by a repellent. However, whether symmetry breaking occurs under high temperature conditions, which are a common abiotic stress, remains unknown. In our study, we deposited a group of Polyrhachis dives ants on a heated platform and counted the number of escaping ants with two identical exits. We discovered that ants asymmetrically escaped through two exits when the temperature of the heated platform was >32.75°C. The degree of asymmetry increased linearly with the temperature of the platform. Furthermore, the higher the temperature of heated platform was, the more ants escaped from the heated platform. However, the number of escaping ants decreased for 3 min when the temperature was higher than the critical thermal limit (39.46°C), which is the threshold for ants to endure high temperature without a loss of performance. Moreover, the ants tended to form small groups to escape from the thermal stress. A preparatory formation of ant grouping was observed before they reached the exit, indicating that the ants actively clustered rather than accidentally gathered at the exits to escape. We suggest that a combination of individual and grouping ants may help to optimize the likelihood of survival during evacuation.

  8. Heat-induced symmetry breaking in ant (Hymenoptera: Formicidae escape behavior.

    Directory of Open Access Journals (Sweden)

    Yuan-Kai Chung

    Full Text Available The collective egress of social insects is important in dangerous situations such as natural disasters or enemy attacks. Some studies have described the phenomenon of symmetry breaking in ants, with two exits induced by a repellent. However, whether symmetry breaking occurs under high temperature conditions, which are a common abiotic stress, remains unknown. In our study, we deposited a group of Polyrhachis dives ants on a heated platform and counted the number of escaping ants with two identical exits. We discovered that ants asymmetrically escaped through two exits when the temperature of the heated platform was >32.75°C. The degree of asymmetry increased linearly with the temperature of the platform. Furthermore, the higher the temperature of heated platform was, the more ants escaped from the heated platform. However, the number of escaping ants decreased for 3 min when the temperature was higher than the critical thermal limit (39.46°C, which is the threshold for ants to endure high temperature without a loss of performance. Moreover, the ants tended to form small groups to escape from the thermal stress. A preparatory formation of ant grouping was observed before they reached the exit, indicating that the ants actively clustered rather than accidentally gathered at the exits to escape. We suggest that a combination of individual and grouping ants may help to optimize the likelihood of survival during evacuation.

  9. A New Method to Monitor the Primary Neutral Integrity in Multi-Grounded Neutral Systems

    OpenAIRE

    Xiangmin Xie; Yuanyuan Sun; Xun Long; Bingwei Zhang

    2017-01-01

    In the three-phase four-wire system, there are usually multiple grounding points in the primary neutral line due to safety and economic considerations. The rising “neutral to earth voltage (NEV)” caused by a broken primary neutral can threaten the safety of nearby facilities and humans; therefore, the integrity of the primary neutral conductor is of vital importance for the multi-grounded neutral (MGN) system. In this paper, a new passive method is proposed to monitor the integrity of the pri...

  10. The impact on neutral voltage of large-scale residential neutral isolation

    International Nuclear Information System (INIS)

    Lanera, D.; Enk, J.; Barna, K.

    1993-01-01

    The impact on neutral-to-earth voltage of large-scale separation of primary and secondary neutral conductors is investigated for a unique rural situation where this has been done over a large area. The study finds that isolating the secondary neutral from the primary neutral, which has been tried successfully in some dairy farm cases, works well even when applied to an entire distribution system, and secondary neutral voltages do go down overall, implying that currents on the secondary side are reduced as well. Neutral isolation at a service transformer can reduce the contribution to the problem of electromagnetic fields (EMF) by the flow of imbalance currents on the customer neutral and grounded conductors. The study points to other important questions of neutral isolation that should be considered next: how well neutral isolation would work in urban settings, whether neutral isolation is less safe than the standard bonding construction, and how much of the EMF problem neutral isolation can help in solving

  11. Control rod driving mechanisms

    International Nuclear Information System (INIS)

    Maejima, Yoshinori.

    1986-01-01

    Purpose: To conduct reactor scram by an external signal and, also by a signal for the abnormal temperature from a temperature detector in the nuclear reactor. Constitution: Control rod driving mechanisms magnetically coupling the extension pipe with the elevating mechanism above the reactor core and the holding magnet, and retains a control rod to the lower portion of the extension pipe by way of a latch mechanism. The temperature detector is immersed in reactor coolants. If the temperature of the coolants rises abnormally, bimetal contacts of the temperature detector are opened to interrupt the current supply to the holding electromagnet. Then, the extension pipe released from the magnetic coupling is lowered and the control rod free from latch is rapidly dropped and inserted into the reactor core. Since this procedure is carried out for all of the control rods, the reactor scram can be attained. The feature of this invention resides in that the reactor scram can be attained also by the signal of the reactor core itself even if the signal system for the external signals should be failed. (Horiuchi, T.)

  12. Driving for shorter outages

    International Nuclear Information System (INIS)

    Tritch, S.

    1996-01-01

    Nuclear plant outages are necessary to complete activities that cannot be completed during the operating cycle, such as steam generator inspection and testing, refueling, installing modifications, and performing maintenance tests. The time devoted to performing outages is normally the largest contributor to plant unavailability. Similarly, outage costs are a sizable portion of the total plant budget. The scope and quality of work done during outages directly affects operating reliability and the number of unplanned outages. Improved management and planning of outages enhances the margin of safety during the outage and results in increased plant reliability. The detailed planning and in-depth preparation that has become a necessity for driving shorter outage durations has also produced safer outages and improved post-outage reliability. Short outages require both plant and vendor management to focus on all aspects of the outage. Short outage durations, such as 26 days at South Texas or 29 days at North Anna, require power plant inter-department and intra-department teamwork and communication and vendor participation. In this paper shorter and safer outage at the 3-loop plants in the United States are explained. (J.P.N.)

  13. Net Neutrality: Media Discourses and Public Perception

    Directory of Open Access Journals (Sweden)

    Christine Quail

    2010-01-01

    Full Text Available This paper analyzes media and public discourses surrounding net neutrality, with particular attention to public utility philosophy, from a critical perspective. The article suggests that further public education about net neutrality would be beneficial. The first portion of this paper provides a survey of the existing literature surrounding net neutrality, highlighting the contentious debate between market-based and public interest perspectives. In order to contextualize the debate, an overview of public utility philosophy is provided, shedding light on how the Internet can be conceptualized as a public good. Following this discussion, an analysis of mainstream media is presented, exploring how the media represents the issue of net neutrality and whether or not the Internet is discussed through the lens of public utility. To further examine how the net neutrality debate is being addressed, and to see the potential impacts of media discourses on the general public, the results of a focus group are reported and analyzed. Finally, a discussion assesses the implications of the net neutrality debate as presented through media discourses, highlighting the future of net neutrality as an important policy issue.

  14. Design of a megawatt neutral injector

    International Nuclear Information System (INIS)

    Coupland, J.R.; Hammond, D.P.; Holmes, A.J.T.; Pedley, T.R.; Roberts, P.J.; Thompson, E.; Ward, B.J.

    1976-01-01

    High power neutral injection plays an increasingly important role in controlled fusion research as a means of heating a magnetically-confined plasma; there is also considerable interest in various beam-fusion energy amplifier systems in which efficient neutral injection plays an essential role. Next generation neutral injection systems will require energies approximately 60-80 keV (H 0 ) for periods approximately 1 sec with power levels approximately 1 MW in the neutral beam. The main features of the design of a prototype megawatt neutral injection system now under construction at Culham is described. The injector is based on the extraction and acceleration of a beam of positive ions followed by conversion to neutral atoms by charge transfer collisions in a gas cell. Details of the design of the four-electrode multi-slot extraction system will be given along with estimates of the (large) gas flow required for the neutralizer gas cell. This large gas load can be handled conveniently only by means of high speed cryopumps and one of the first aims of the programme is to evaluate the performance of large (1 m 2 ) liquid helium cooled cryo-panels for this application. A brief description of the main high voltage and auxiliary power supplies along with some aspects of the novel high voltage protection system we have proposed are also discussed

  15. Neutral Supersymmetric Higgs Boson Searches

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, Stephen Luke [Imperial College, London (United Kingdom)

    2008-07-01

    In some Supersymmetric extensions of the Standard Model, including the Minimal Supersymmetric Standard Model (MSSM), the coupling of Higgs bosons to b-quarks is enhanced. This enhancement makes the associated production of the Higgs with b-quarks an interesting search channel for the Higgs and Supersymmetry at D0. The identification of b-quarks, both online and offline, is essential to this search effort. This thesis describes the author's involvement in the development of both types of b-tagging and in the application of these techniques to the MSSM Higgs search. Work was carried out on the Level-3 trigger b-tagging algorithms. The impact parameter (IP) b-tagger was retuned and the effects of increased instantaneous luminosity on the tagger were studied. An extension of the IP-tagger to use the z-tracking information was developed. A new b-tagger using secondary vertices was developed and commissioned. A tool was developed to allow the use of large multi-run samples for trigger studies involving b-quarks. Offline, a neural network (NN) b-tagger was trained combining the existing offline lifetime based b-tagging tools. The efficiency and fake rate of the NN b-tagger were measured in data and MC. This b-tagger was internally reviewed and certified by the Collaboration and now provides the official b-tagging for all analyses using the Run IIa dataset at D0. A search was performed for neutral MSSM Higgs bosons decaying to a b{bar b} pair and produced in association with one or more b-quarks. Limits are set on the cross-section times the branching ratio for such a process. The limits were interpreted in various MSSM scenarios. This analysis uses the NN b-tagger and was the first to use this tool. The analysis also relies on triggers using the Level-3 IP b-tagging tool described previously. A likelihood discriminant was used to improve the analysis and a neural network was developed to cross-check this technique. The result of the analysis has been submitted to PRL

  16. Neutral currents, supernovae neutrinos, and nucleosynthesis

    International Nuclear Information System (INIS)

    Haxton, W.C.

    1988-01-01

    The inelastic interactions of neutrinos during stellar collapse and neutron star cooling are discussed. The primary mechanism for dissipative neutrino reactions is nuclear excitation by neutral current scattering, a process not included in standard descriptions of supernovae. Charge-current and neutral current ''preheating'' of iron lying outside the shock front appears to be significant in the few milliseconds near shock breakout. This could help produce a more energetic shock. During the cooling phase, the neutral current interactions of muon and taon neutrinos appear to be responsible for some interesting nucleosynthesis. I discuss two examples the production of fluorine and neutrino-induced r-process nucleosynthesis. 26 refs., 1 fig., 3 tabs

  17. Rare decays of neutral π and eta

    International Nuclear Information System (INIS)

    Poutissou, J.M.

    1983-09-01

    The decays of the pseudoscalar neutral mesons π degree and eta degree have provided a test of fundamental principles. The main branch, π degree → 2γ, was investigated in the late 60's in the context of current algebra and the decay rate calculated from the singular triangle diagram is in excellent agreement with experiment. Rare leptonic decays of the neutral pseudoscalar mesons are of interest because of the information they reveal about neutral currents or other exotic interactions between leptons and quarks. The author discusses recent information on the π degree → e + e - decay

  18. Electric vehicle drive systems

    Science.gov (United States)

    Appleyard, M.

    1992-01-01

    New legislation in the State of California requires that 2% of vehicles sold there from 1998 will be 'zero-emitting'. This provides a unique market opportunity for developers of electric vehicles but substantial improvements in the technology are probably required if it is to be successfully exploited. There are around a dozen types of battery that are potentially relevant to road vehicles but, at the present, lead/acid and sodium—sulphur come closest to combining acceptable performance, life and cost. To develop an efficient, lightweight electric motor system requires up-to-date techniques of magnetics design, and the latest power-electronic and microprocessor control methods. Brushless machines, coupled with solid-state inverters, offer the most economical solution for mass production, even though their development costs are higher than for direct-current commutator machines. Fitted to a small car, even the highest energy-density batteries will only provide around 200 km average range before recharging. Therefore, some form of supplementary on-board power generation will probably be needed to secure widespread acceptance by the driving public. Engine-driven generators of quite low power can achieve useful increases in urban range but will fail to qualify as 'zero-emitting'. On the other hand, if the same function could be economically performed by a small fuel-cell using hydrogen derived from a methanol reformer, then most of the flexibility provided by conventional vehicles would be retained. The market prospects for electric cars would then be greatly enhanced and their dependence on very advanced battery technology would be reduced.

  19. The first human epitope map of the alphaviral E1 and E2 proteins reveals a new E2 epitope with significant virus neutralizing activity.

    Directory of Open Access Journals (Sweden)

    Ann R Hunt

    2010-07-01

    Full Text Available Venezuelan equine encephalitis virus (VEEV is responsible for VEE epidemics that occur in South and Central America and the U.S. The VEEV envelope contains two glycoproteins E1 (mediates cell membrane fusion and E2 (binds receptor and elicits virus neutralizing antibodies. Previously we constructed E1 and E2 epitope maps using murine monoclonal antibodies (mMAbs. Six E2 epitopes (E2(c,d,e,f,g,h bound VEEV-neutralizing antibody and mapped to amino acids (aa 182-207. Nothing is known about the human antibody repertoire to VEEV or epitopes that engage human virus-neutralizing antibodies. There is no specific treatment for VEE; however virus-neutralizing mMAbs are potent protective and therapeutic agents for mice challenged with VEEV by either peripheral or aerosol routes. Therefore, fully human MAbs (hMAbs with virus-neutralizing activity should be useful for prevention or clinical treatment of human VEE.We used phage-display to isolate VEEV-specific hFabs from human bone marrow donors. These hFabs were characterized by sequencing, specificity testing, VEEV subtype cross-reactivity using indirect ELISA, and in vitro virus neutralization capacity. One E2-specific neutralizing hFAb, F5n, was converted into IgG, and its binding site was identified using competitive ELISA with mMAbs and by preparing and sequencing antibody neutralization-escape variants.Using 11 VEEV-reactive hFabs we constructed the first human epitope map for the alphaviral surface proteins E1 and E2. We identified an important neutralization-associated epitope unique to the human immune response, E2 aa115-119. Using a 9 A resolution cryo-electron microscopy map of the Sindbis virus E2 protein, we showed the probable surface location of this human VEEV epitope.The VEEV-neutralizing capacity of the hMAb F5 nIgG is similar to that exhibited by the humanized mMAb Hy4 IgG. The Hy4 IgG has been shown to limit VEEV infection in mice both prophylactically and therapeutically. Administration

  20. The first human epitope map of the alphaviral E1 and E2 proteins reveals a new E2 epitope with significant virus neutralizing activity.

    Science.gov (United States)

    Hunt, Ann R; Frederickson, Shana; Maruyama, Toshiaki; Roehrig, John T; Blair, Carol D

    2010-07-13

    Venezuelan equine encephalitis virus (VEEV) is responsible for VEE epidemics that occur in South and Central America and the U.S. The VEEV envelope contains two glycoproteins E1 (mediates cell membrane fusion) and E2 (binds receptor and elicits virus neutralizing antibodies). Previously we constructed E1 and E2 epitope maps using murine monoclonal antibodies (mMAbs). Six E2 epitopes (E2(c,d,e,f,g,h)) bound VEEV-neutralizing antibody and mapped to amino acids (aa) 182-207. Nothing is known about the human antibody repertoire to VEEV or epitopes that engage human virus-neutralizing antibodies. There is no specific treatment for VEE; however virus-neutralizing mMAbs are potent protective and therapeutic agents for mice challenged with VEEV by either peripheral or aerosol routes. Therefore, fully human MAbs (hMAbs) with virus-neutralizing activity should be useful for prevention or clinical treatment of human VEE. We used phage-display to isolate VEEV-specific hFabs from human bone marrow donors. These hFabs were characterized by sequencing, specificity testing, VEEV subtype cross-reactivity using indirect ELISA, and in vitro virus neutralization capacity. One E2-specific neutralizing hFAb, F5n, was converted into IgG, and its binding site was identified using competitive ELISA with mMAbs and by preparing and sequencing antibody neutralization-escape variants. Using 11 VEEV-reactive hFabs we constructed the first human epitope map for the alphaviral surface proteins E1 and E2. We identified an important neutralization-associated epitope unique to the human immune response, E2 aa115-119. Using a 9 A resolution cryo-electron microscopy map of the Sindbis virus E2 protein, we showed the probable surface location of this human VEEV epitope. The VEEV-neutralizing capacity of the hMAb F5 nIgG is similar to that exhibited by the humanized mMAb Hy4 IgG. The Hy4 IgG has been shown to limit VEEV infection in mice both prophylactically and therapeutically. Administration of a

  1. Escape Excel: A tool for preventing gene symbol and accession conversion errors

    Science.gov (United States)

    Stewart, Paul A.; Kuenzi, Brent M.; Eschrich, James A.

    2017-01-01

    Background Microsoft Excel automatically converts certain gene symbols, database accessions, and other alphanumeric text into dates, scientific notation, and other numerical representations. These conversions lead to subsequent, irreversible, corruption of the imported text. A recent survey of popular genomic literature estimates that one-fifth of all papers with supplementary gene lists suffer from this issue. Results Here, we present an open-source tool, Escape Excel, which prevents these erroneous conversions by generating an escaped text file that can be safely imported into Excel. Escape Excel is implemented in a variety of formats (http://www.github.com/pstew/escape_excel), including a command line based Perl script, a Windows-only Excel Add-In, an OS X drag-and-drop application, a simple web-server, and as a Galaxy web environment interface. Test server implementations are accessible as a Galaxy interface (http://apostl.moffitt.org) and simple non-Galaxy web server (http://apostl.moffitt.org:8000/). Conclusions Escape Excel detects and escapes a wide variety of problematic text strings so that they are not erroneously converted into other representations upon importation into Excel. Examples of problematic strings include date-like strings, time-like strings, leading zeroes in front of numbers, and long numeric and alphanumeric identifiers that should not be automatically converted into scientific notation. It is hoped that greater awareness of these potential data corruption issues, together with diligent escaping of text files prior to importation into Excel, will help to reduce the amount of Excel-corrupted data in scientific analyses and publications. PMID:28953918

  2. Temporal and ontogenetic variation in the escape response of Ameiva festiva (Squamata, Teiidae

    Directory of Open Access Journals (Sweden)

    Lattanzio

    2014-08-01

    Full Text Available Several factors have been shown to affect lizard escape behavior (flight initiation distance or FID, the distance between predator and prey when the prey initiates escape. Patterns of daily activity, such as foraging or movement behavior, vary with respect to time of day, supporting that escape responses may vary temporally as well. However, there remains scant information regarding the effects of time of day on FID. During peak activity, FID may decrease due to increased cost of giving up resources (e.g., prey or potential mates. An alternative hypothesis is that FID may increase because lizard activity in general may serve to alert a predator in advance of its approach. A lizard in this scenario may be favored to flee sooner rather than later. Moreover, juvenile and adult lizards of multiple species may differ in behavioral, ecological, and morphological traits that could influence escape decisions. I tested the effects of time of day (in 30-min intervals and age (juvenile or adult on the FID of a tropical whiptail lizard, Ameiva festiva in Costa Rica. I found that A. festiva escape responses varied with time of day such that in general, their FID decreased throughout the day. In addition, I observed a peak in FID from mid to late-morning that matches published estimates of peak activity times for A. festiva. Overall, juvenile A. festiva initiated an escape response sooner than adults, which may be related to differences in perceived risk associated with differences in size and predator experience between the two age groups. I conclude that escape responses may be contingent on both the activity level of the animal at the time of approach and its age.

  3. Phylogenetic dependency networks: inferring patterns of CTL escape and codon covariation in HIV-1 Gag.

    Directory of Open Access Journals (Sweden)

    Jonathan M Carlson

    2008-11-01

    Full Text Available HIV avoids elimination by cytotoxic T-lymphocytes (CTLs through the evolution of escape mutations. Although there is mounting evidence that these escape pathways are broadly consistent among individuals with similar human leukocyte antigen (HLA class I alleles, previous population-based studies have been limited by the inability to simultaneously account for HIV codon covariation, linkage disequilibrium among HLA alleles, and the confounding effects of HIV phylogeny when attempting to identify HLA-associated viral evolution. We have developed a statistical model of evolution, called a phylogenetic dependency network, that accounts for these three sources of confounding and identifies the primary sources of selection pressure acting on each HIV codon. Using synthetic data, we demonstrate the utility of this approach for identifying sites of HLA-mediated selection pressure and codon evolution as well as the deleterious effects of failing to account for all three sources of confounding. We then apply our approach to a large, clinically-derived dataset of Gag p17 and p24 sequences from a multicenter cohort of 1144 HIV-infected individuals from British Columbia, Canada (predominantly HIV-1 clade B and Durban, South Africa (predominantly HIV-1 clade C. The resulting phylogenetic dependency network is dense, containing 149 associations between HLA alleles and HIV codons and 1386 associations among HIV codons. These associations include the complete reconstruction of several recently defined escape and compensatory mutation pathways and agree with emerging data on patterns of epitope targeting. The phylogenetic dependency network adds to the growing body of literature suggesting that sites of escape, order of escape, and compensatory mutations are largely consistent even across different clades, although we also identify several differences between clades. As recent case studies have demonstrated, understanding both the complexity and the consistency of

  4. Orbital and escape dynamics in barred galaxies - I. The 2D system

    Science.gov (United States)

    Jung, Christof; Zotos, Euaggelos E.

    2016-04-01

    In this paper, we use the two-dimensional version of a new analytical gravitational model in order to explore the orbital as well as the escape dynamics of the stars in a barred galaxy composed of a spherically symmetric central nucleus, a bar, a flat disc and a dark matter halo component. A thorough numerical investigation is conducted for distinguishing between bounded and escaping motion. Furthermore, bounded orbits are further classified into non-escaping regular and trapped chaotic using the Smaller ALingment Index method. Our aim is to determine the basins of escape through the two symmetrical escape channels around the Lagrange points L2 and L3 and also to relate them with the corresponding distribution of the escape rates of the orbits. We integrate initial conditions of orbits in several types of planes so as to obtain a more complete view of the overall orbital properties of the dynamical system. We also present evidence that the unstable manifolds which guide the orbits in and out the interior region are directly related with the formation of spiral and ring stellar structures observed in barred galaxies. In particular, we examine how the bar's semimajor axis determines the resulting morphologies. Our numerical simulations indicate that weak barred structures favour the formation of R1 rings or R_1^' } pseudo-rings, while strong bars on the other hand, give rise to R1R2 and open spiral morphologies. Our results are compared with earlier related work. The escape dynamics and the properties of the manifolds of the full three-dimensional galactic system will be given in an accompanying paper.

  5. Escape Excel: A tool for preventing gene symbol and accession conversion errors.

    Science.gov (United States)

    Welsh, Eric A; Stewart, Paul A; Kuenzi, Brent M; Eschrich, James A

    2017-01-01

    Microsoft Excel automatically converts certain gene symbols, database accessions, and other alphanumeric text into dates, scientific notation, and other numerical representations. These conversions lead to subsequent, irreversible, corruption of the imported text. A recent survey of popular genomic literature estimates that one-fifth of all papers with supplementary gene lists suffer from this issue. Here, we present an open-source tool, Escape Excel, which prevents these erroneous conversions by generating an escaped text file that can be safely imported into Excel. Escape Excel is implemented in a variety of formats (http://www.github.com/pstew/escape_excel), including a command line based Perl script, a Windows-only Excel Add-In, an OS X drag-and-drop application, a simple web-server, and as a Galaxy web environment interface. Test server implementations are accessible as a Galaxy interface (http://apostl.moffitt.org) and simple non-Galaxy web server (http://apostl.moffitt.org:8000/). Escape Excel detects and escapes a wide variety of problematic text strings so that they are not erroneously converted into other representations upon importation into Excel. Examples of problematic strings include date-like strings, time-like strings, leading zeroes in front of numbers, and long numeric and alphanumeric identifiers that should not be automatically converted into scientific notation. It is hoped that greater awareness of these potential data corruption issues, together with diligent escaping of text files prior to importation into Excel, will help to reduce the amount of Excel-corrupted data in scientific analyses and publications.

  6. Escape Excel: A tool for preventing gene symbol and accession conversion errors.

    Directory of Open Access Journals (Sweden)

    Eric A Welsh

    Full Text Available Microsoft Excel automatically converts certain gene symbols, database accessions, and other alphanumeric text into dates, scientific notation, and other numerical representations. These conversions lead to subsequent, irreversible, corruption of the imported text. A recent survey of popular genomic literature estimates that one-fifth of all papers with supplementary gene lists suffer from this issue.Here, we present an open-source tool, Escape Excel, which prevents these erroneous conversions by generating an escaped text file that can be safely imported into Excel. Escape Excel is implemented in a variety of formats (http://www.github.com/pstew/escape_excel, including a command line based Perl script, a Windows-only Excel Add-In, an OS X drag-and-drop application, a simple web-server, and as a Galaxy web environment interface. Test server implementations are accessible as a Galaxy interface (http://apostl.moffitt.org and simple non-Galaxy web server (http://apostl.moffitt.org:8000/.Escape Excel detects and escapes a wide variety of problematic text strings so that they are not erroneously converted into other representations upon importation into Excel. Examples of problematic strings include date-like strings, time-like strings, leading zeroes in front of numbers, and long numeric and alphanumeric identifiers that should not be automatically converted into scientific notation. It is hoped that greater awareness of these potential data corruption issues, together with diligent escaping of text files prior to importation into Excel, will help to reduce the amount of Excel-corrupted data in scientific analyses and publications.

  7. Foundational errors in the Neutral and Nearly-Neutral theories of evolution in relation to the Synthetic Theory: is a new evolutionary paradigm necessary?

    Science.gov (United States)

    Valenzuela, Carlos Y

    2013-01-01

    The Neutral Theory of Evolution (NTE) proposes mutation and random genetic drift as the most important evolutionary factors. The most conspicuous feature of evolution is the genomic stability during paleontological eras and lack of variation among taxa; 98% or more of nucleotide sites are monomorphic within a species. NTE explains this homology by random fixation of neutral bases and negative selection (purifying selection) that does not contribute either to evolution or polymorphisms. Purifying selection is insufficient to account for this evolutionary feature and the Nearly-Neutral Theory of Evolution (N-NTE) included negative selection with coefficients as low as mutation rate. These NTE and N-NTE propositions are thermodynamically (tendency to random distributions, second law), biotically (recurrent mutation), logically and mathematically (resilient equilibria instead of fixation by drift) untenable. Recurrent forward and backward mutation and random fluctuations of base frequencies alone in a site make life organization and fixations impossible. Drift is not a directional evolutionary factor, but a directional tendency of matter-energy processes (second law) which threatens the biotic organization. Drift cannot drive evolution. In a site, the mutation rates among bases and selection coefficients determine the resilient equilibrium frequency of bases that genetic drift cannot change. The expected neutral random interaction among nucleotides is zero; however, huge interactions and periodicities were found between bases of dinucleotides separated by 1, 2... and more than 1,000 sites. Every base is co-adapted with the whole genome. Neutralists found that neutral evolution is independent of population size (N); thus neutral evolution should be independent of drift, because drift effect is dependent upon N. Also, chromosome size and shape as well as protein size are far from random.

  8. Linear Back-Drive Differentials

    Science.gov (United States)

    Waydo, Peter

    2003-01-01

    Linear back-drive differentials have been proposed as alternatives to conventional gear differentials for applications in which there is only limited rotational motion (e.g., oscillation). The finite nature of the rotation makes it possible to optimize a linear back-drive differential in ways that would not be possible for gear differentials or other differentials that are required to be capable of unlimited rotation. As a result, relative to gear differentials, linear back-drive differentials could be more compact and less massive, could contain fewer complex parts, and could be less sensitive to variations in the viscosities of lubricants. Linear back-drive differentials would operate according to established principles of power ball screws and linear-motion drives, but would utilize these principles in an innovative way. One major characteristic of such mechanisms that would be exploited in linear back-drive differentials is the possibility of designing them to drive or back-drive with similar efficiency and energy input: in other words, such a mechanism can be designed so that a rotating screw can drive a nut linearly or the linear motion of the nut can cause the screw to rotate. A linear back-drive differential (see figure) would include two collinear shafts connected to two parts that are intended to engage in limited opposing rotations. The linear back-drive differential would also include a nut that would be free to translate along its axis but not to rotate. The inner surface of the nut would be right-hand threaded at one end and left-hand threaded at the opposite end to engage corresponding right- and left-handed threads on the shafts. A rotation and torque introduced into the system via one shaft would drive the nut in linear motion. The nut, in turn, would back-drive the other shaft, creating a reaction torque. Balls would reduce friction, making it possible for the shaft/nut coupling on each side to operate with 90 percent efficiency.

  9. Cosmic Ray Self-Confinement, Escape and Transport

    Science.gov (United States)

    Malkov, Mikhail

    2014-10-01

    Propagation of cosmic rays (CR) in a self-confinement regime is discussed. A self-similar solution for a CR-cloud expansion along the magnetic field strongly deviates from test-particle results. The normalized CR partial pressure is close to P (p , z , t) = 2 [ | z |5/3 +zdif5 / 3 (p , t) ]- 3 / 5 exp [ -z2 / 4DB (p) t ] , where p is the momentum of CR and z is directed along the field. The core of the cloud expands as zdif ~√{DNL p t } and decays in time as P ~ 2zdif- 1 (t) . The diffusion coefficient DNL is strongly suppressed compared to its background value DB: DNL ~DB exp - Π > 1 , the CRs drive Alfven waves efficiently enough to build a transport barrier (P ~ 2 / | z | -``pedestal'') that strongly reduces the leakage. The solution has a spectral break in momentum spectrum at p =pbr , where pbr satisfies the following equation DNLpbr ~=z2 / t . Magnetic focusing effects in CR transport are briefly discussed. Partially supported by NASA through ATP NNX14AH36G.

  10. UV Ionizer for Neutral Wind Mass Spectrometers

    Data.gov (United States)

    National Aeronautics and Space Administration — Current neutral particle instrumentation relies on hot cathode filaments or an electron gun for ionizing the target medium.  These ionization sources represent a...

  11. XUV-exposed, non-hydrostatic hydrogen-rich upper atmospheres of terrestrial planets. Part II: hydrogen coronae and ion escape.

    Science.gov (United States)

    Kislyakova, Kristina G; Lammer, Helmut; Holmström, Mats; Panchenko, Mykhaylo; Odert, Petra; Erkaev, Nikolai V; Leitzinger, Martin; Khodachenko, Maxim L; Kulikov, Yuri N; Güdel, Manuel; Hanslmeier, Arnold

    2013-11-01

    We studied the interactions between the stellar wind plasma flow of a typical M star, such as GJ 436, and the hydrogen-rich upper atmosphere of an Earth-like planet and a "super-Earth" with a radius of 2 R(Earth) and a mass of 10 M(Earth), located within the habitable zone at ∼0.24 AU. We investigated the formation of extended atomic hydrogen coronae under the influences of the stellar XUV flux (soft X-rays and EUV), stellar wind density and velocity, shape of a planetary obstacle (e.g., magnetosphere, ionopause), and the loss of planetary pickup ions on the evolution of hydrogen-dominated upper atmospheres. Stellar XUV fluxes that are 1, 10, 50, and 100 times higher compared to that of the present-day Sun were considered, and the formation of high-energy neutral hydrogen clouds around the planets due to the charge-exchange reaction under various stellar conditions was modeled. Charge-exchange between stellar wind protons with planetary hydrogen atoms, and photoionization, lead to the production of initially cold ions of planetary origin. We found that the ion production rates for the studied planets can vary over a wide range, from ∼1.0×10²⁵ s⁻¹ to ∼5.3×10³⁰ s⁻¹, depending on the stellar wind conditions and the assumed XUV exposure of the upper atmosphere. Our findings indicate that most likely the majority of these planetary ions are picked up by the stellar wind and lost from the planet. Finally, we estimated the long-time nonthermal ion pickup escape for the studied planets and compared them with the thermal escape. According to our estimates, nonthermal escape of picked-up ionized hydrogen atoms over a planet's lifetime within the habitable zone of an M dwarf varies between ∼0.4 Earth ocean equivalent amounts of hydrogen (EO(H)) to <3 EO(H) and usually is several times smaller in comparison to the thermal atmospheric escape rates.

  12. Tissue Dissociation Enzyme Neutral Protease Assessment

    OpenAIRE

    Breite, A.G.; Dwulet, F.E.; McCarthy, R.C.

    2010-01-01

    Neutral proteases, essential components of purified tissue dissociation enzymes required for successful human islet isolation, show variable activities and effects of substrate on their activities. Initially we used a spectrophotometric endpoint assay with azocasein substrate to measure neutral protease activity. After critical review of the results, we observed these data to be inconsistent and not correlating expected differences in specific activities between thermolysin and Bacillus polym...

  13. Neutralization of H- beams by magnetic stripping

    International Nuclear Information System (INIS)

    Jason, A.J.; Hudgings, D.W.; van Dyck, O.B.

    1981-01-01

    The stability of H - beams passing through strong magnetic fields has been relevant to accelerator transport problems and, recently, to neutral beam preparation techniques. The H - electron detachment rate was measured as a function of rest-frame electric field and provides parameters for a theoretical lifetime expression. The limitations imposed on H - transport by magnetic stripping, and neutral-beam preparation in emittance growth, magnetic fields, and beam energies are discussed. Application techniques are also briefly discussed

  14. Negative ion formation and neutralization processes, (1)

    International Nuclear Information System (INIS)

    Sugiura, Toshio

    1982-01-01

    This review has been made preliminary for the purpose of contribute to the plasma heating by ''negative ion based neutral beam injection'' in the magnetic confinement fusion reactor. A compilation includes the survey of the general processes of negative ion formation, the data of the cross section of H - ion formation and the neutralization of H - ion, and some of new processes of H - ion formation. The data of cross section are mainly experimental, but partly include the results of theoretical calculation. (author)

  15. Inducing Risk Neutral Preferences with Binary Lotteries

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd

    2013-01-01

    We evaluate the binary lottery procedure for inducing risk neutral behavior. We strip the experimental implementation down to bare bones, taking care to avoid any potentially confounding assumptions about behavior having to be made. In particular, our evaluation does not rely on the assumed valid...... toward risk neutrality. This striking result generalizes to the case in which subjects make several lottery choices and one is selected for payment....

  16. Neutral currents without gauge theory prejudices

    International Nuclear Information System (INIS)

    Sakurai, J.J.

    1976-01-01

    The measurement of weak neutral current processes allows a determination of the space-time structure and the isospin structure of these currents. The inclusive production data and the elastic neutrino electron scattering rules out a pure V or A structure of the current. A pure isoscalar current is in disagreement with the experimental data for the one pion production off neutrinos. Further aspects of the neutral current can be determined in neutrino-nucleus-scattering experiments. (BJ) [de

  17. Nitrogen-neutrality: a step towards sustainability

    Science.gov (United States)

    Leip, Adrian; Leach, Allison; Musinguzi, Patrick; Tumwesigye, Trust; Olupot, Giregon; Tenywa, John Stephen; Mudiope, Joseph; Hutton, Olivia; Cordovil, Claudia M. d. S.; Bekunda, Mateete; Galloway, James

    2014-11-01

    We propose a novel indicator measuring one dimension of the sustainability of an entity in modern societies: Nitrogen-neutrality. N-neutrality strives to offset Nr releases an entity exerts on the environment from the release of reactive nitrogen (Nr) to the environment by reducing it and by offsetting the Nr releases elsewhere. N-neutrality also aims to increase awareness about the consequences of unintentional releases of nitrogen to the environment. N-neutrality is composed of two quantified elements: Nr released by an entity (e.g. on the basis of the N footprint) and Nr reduction from management and offset projects (N offset). It includes management strategies to reduce nitrogen losses before they occur (e.g., through energy conservation). Each of those elements faces specific challenges with regard to data availability and conceptual development. Impacts of Nr releases to the environment are manifold, and the impact profile of one unit of Nr release depends strongly on the compound released and the local susceptibility to Nr. As such, N-neutrality is more difficult to conceptualize and calculate than C-neutrality. We developed a workable conceptual framework for N-neutrality which was adapted for the 6th International Nitrogen Conference (N2013, Kampala, November 2013). Total N footprint of the surveyed meals at N2013 was 66 kg N. A total of US 3050 was collected from the participants and used to offset the conference’s N footprint by supporting the UN Millennium Village cluster Ruhiira in South-Western Uganda. The concept needs further development in particular to better incorporate the spatio-temporal variability of impacts and to standardize the methods to quantify the required N offset to neutralize the Nr releases impact. Criteria for compensation projects need to be sharply defined to allow the development of a market for N offset certificates.

  18. Nitrogen-neutrality: a step towards sustainability

    International Nuclear Information System (INIS)

    Leip, Adrian; Leach, Allison; Hutton, Olivia; Galloway, James; Musinguzi, Patrick; Tumwesigye, Trust; Olupot, Giregon; Stephen Tenywa, John; Mudiope, Joseph; Cordovil, Claudia M d S; Bekunda, Mateete

    2014-01-01

    We propose a novel indicator measuring one dimension of the sustainability of an entity in modern societies: Nitrogen-neutrality. N-neutrality strives to offset Nr releases an entity exerts on the environment from the release of reactive nitrogen (Nr) to the environment by reducing it and by offsetting the Nr releases elsewhere. N-neutrality also aims to increase awareness about the consequences of unintentional releases of nitrogen to the environment. N-neutrality is composed of two quantified elements: Nr released by an entity (e.g. on the basis of the N footprint) and Nr reduction from management and offset projects (N offset). It includes management strategies to reduce nitrogen losses before they occur (e.g., through energy conservation). Each of those elements faces specific challenges with regard to data availability and conceptual development. Impacts of Nr releases to the environment are manifold, and the impact profile of one unit of Nr release depends strongly on the compound released and the local susceptibility to Nr. As such, N-neutrality is more difficult to conceptualize and calculate than C-neutrality. We developed a workable conceptual framework for N-neutrality which was adapted for the 6th International Nitrogen Conference (N2013, Kampala, November 2013). Total N footprint of the surveyed meals at N2013 was 66 kg N. A total of US$ 3050 was collected from the participants and used to offset the conference’s N footprint by supporting the UN Millennium Village cluster Ruhiira in South-Western Uganda. The concept needs further development in particular to better incorporate the spatio-temporal variability of impacts and to standardize the methods to quantify the required N offset to neutralize the Nr releases impact. Criteria for compensation projects need to be sharply defined to allow the development of a market for N offset certificates. (paper)

  19. Negative ion based neutral beams for plasma heating

    International Nuclear Information System (INIS)

    Prelec, K.

    1978-01-01

    Neutral beam systems based on negative ions have been considered because of a high expected power efficiency. Methods for the production, acceleration and neutralization of negative ions will be reviewed and possibilities for an application in neutral beam lines explored

  20. Automated driving safer and more efficient future driving

    CERN Document Server

    Horn, Martin

    2017-01-01

    The main topics of this book include advanced control, cognitive data processing, high performance computing, functional safety, and comprehensive validation. These topics are seen as technological bricks to drive forward automated driving. The current state of the art of automated vehicle research, development and innovation is given. The book also addresses industry-driven roadmaps for major new technology advances as well as collaborative European initiatives supporting the evolvement of automated driving. Various examples highlight the state of development of automated driving as well as the way forward. The book will be of interest to academics and researchers within engineering, graduate students, automotive engineers at OEMs and suppliers, ICT and software engineers, managers, and other decision-makers.