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Sample records for americanus induces neutralizing

  1. Induced resistance to infection of lobsters Homarus americanus by Aerococcus viridans (var.) homari, the bacterium causing gaffkemia.

    Science.gov (United States)

    Stewart, James E; Arie, B; Marks, L J

    2004-12-13

    A vaccine composed of steam sterilized (autoclaved) cells of a virulent strain of Aerococcus viridans (var.) homari was effective in protecting lobsters Homarus americanus against gaffkemia. At 15 degrees C the heat-killed vaccines (HKV) at concentrations between 1 and 5 x 10(7) particles kg(-1) lobster body wt induced maximal protection in induction periods ranging from 7 to 11 d. Protection was substantial over the course of a 30 d post-induction trial period. Spring-caught lobsters (i.e. those more fully rehabilitated following ecdysis) gained more protection (LD50 = 1.9 x 10(4)) from the vaccination than did those caught in the late fall-early winter period (lobsters that were not yet fully recovered from ecdysis) (LD50 = 3.2 x 10(3)). The protection offered by the HK vaccine was comparable to that induced by a vaccine produced by incubating the pathogen with low concentrations (2 pg ml(-1)) of the antibiotic vancomycin. The bacterins produced by both methods exhibited similar new properties: (1) agglutination at low titres by lobster hemolymph serum, suggesting an impaired capsule layer, and (2) increased permeability to the large Alcian Blue molecule. With both vaccines, the protection may be a direct result of increased exposure to intact bacterial cell structures by the lobster defences, an exposure which otherwise would be prevented by an intact capsule.

  2. Inducing Risk Neutral Preferences with Binary Lotteries

    DEFF Research Database (Denmark)

    Harrison, Glenn W.; Martínez-Correa, Jimmy; Swarthout, J. Todd

    2013-01-01

    validity of any strategic equilibrium behavior, or even the customary independence axiom. We show that subjects sampled from our population are generally risk averse when lotteries are defined over monetary outcomes, and that the binary lottery procedure does indeed induce a statistically significant shift......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...... toward risk neutrality. This striking result generalizes to the case in which subjects make several lottery choices and one is selected for payment....

  3. Neutral current induced neutrino oscillations in a supernova

    CERN Document Server

    Kusenko, A; Kusenko, Alexander; Segre, Gino

    1997-01-01

    Neutral currents induced matter oscillations of electroweak-active (anti-)neutrinos to sterile neutrinos can explain the observed motion of pulsars. In contrast to a recently proposed explanation of the pulsar birth velocities based on the electron to tau (muon) neutrino oscillations [hep-ph/9606428], the heaviest neutrino (either active or sterile) would have to have mass of order several keV.

  4. Dual neutral particle induced transmutation in CINDER2008

    Energy Technology Data Exchange (ETDEWEB)

    Martin, W.J., E-mail: wjmarti@sandia.gov [Sandia National Laboratories, Albuquerque, NM 87185 (United States); University of New Mexico, Albuquerque, NM 87131 (United States); Oliveira, C.R.E. de; Hecht, A.A. [University of New Mexico, Albuquerque, NM 87131 (United States)

    2014-12-11

    Although nuclear transmutation methods for fission have existed for decades, the focus has been on neutron-induced reactions. Recent novel concepts have sought to use both neutrons and photons for purposes such as active interrogation of cargo to detect the smuggling of highly enriched uranium, a concept that would require modeling the transmutation caused by both incident particles. As photonuclear transmutation has yet to be modeled alongside neutron-induced transmutation in a production code, new methods need to be developed. The CINDER2008 nuclear transmutation code from Los Alamos National Laboratory is extended from neutron applications to dual neutral particle applications, allowing both neutron- and photon-induced reactions for this modeling with a focus on fission. Following standard reaction modeling, the induced fission reaction is understood as a two-part reaction, with an entrance channel to the excited compound nucleus, and an exit channel from the excited compound nucleus to the fission fragmentation. Because photofission yield data—the exit channel from the compound nucleus—are sparse, neutron fission yield data are used in this work. With a different compound nucleus and excitation, the translation to the excited compound state is modified, as appropriate. A verification and validation of these methods and data has been performed. This has shown that the translation of neutron-induced fission product yield sets, and their use in photonuclear applications, is appropriate, and that the code has been extended correctly. - Highlights: • The CINDER2008 transmutation code was modified to include photon-induced transmutation tracking. • A photonuclear interaction library was created to allow CINDER2008 to track photonuclear interactions. • Photofission product yield data sets were created using fission physics similarities with neutron-induced fission.

  5. Trypanosomes of Bufo americanus from northern Michigan.

    Science.gov (United States)

    Werner, J K; Davis, J S; Slaght, K S

    1988-10-01

    Two hundred one American toads (Bufo americanus) from northern Michigan were examined for blood trypanosomes. Three species, Trypanosoma bufophlebotomi, T. schmidti-like sp. and T. pseudopodia, had prevalences of 27, 16 and 1%, respectively. Cross experimental inoculations showed that T. bufophlebotomi from toads is not the same as T. ranarum found in frogs of the family Ranidae of this region.

  6. HIV-1 neutralizing antibodies induced by native-like envelope trimers

    NARCIS (Netherlands)

    Sanders, Rogier W.; van Gils, Marit J.; Derking, Ronald; Sok, Devin; Ketas, Thomas J.; Burger, Judith A.; Ozorowski, Gabriel; Cupo, Albert; Simonich, Cassandra; Goo, Leslie; Arendt, Heather; Kim, Helen J.; Lee, Jeong Hyun; Pugach, Pavel; Williams, Melissa; Debnath, Gargi; Moldt, Brian; van Breemen, Mariëlle J.; Isik, Gözde; Medina-Ramírez, Max; Back, Jaap Willem; Koff, Wayne C.; Julien, Jean-Philippe; Rakasz, Eva G.; Seaman, Michael S.; Guttman, Miklos; Lee, Kelly K.; Klasse, Per Johan; Labranche, Celia; Schief, William R.; Wilson, Ian A.; Overbaugh, Julie; Burton, Dennis R.; Ward, Andrew B.; Montefiori, David C.; Dean, Hansi; Moore, John P.

    2015-01-01

    A challenge for HIV-1 immunogen design is the difficulty of inducing neutralizing antibodies (NAbs) against neutralization-resistant (tier 2) viruses that dominate human transmissions. We show that a soluble recombinant HIV-1 envelope glycoprotein trimer that adopts a native conformation, BG505

  7. Determination of neutral current couplings from neutrino-induced semi-inclusive pion and inclusive reactions

    International Nuclear Information System (INIS)

    Hung, P.Q.

    1977-01-01

    It is shown that by looking at data from neutrino-induced semi-inclusive pion and inclusive reactions on isoscalar targets along, one can determine completely the neutral current couplings. Predictions for various models are also presented. (Auth.)

  8. Non-invasive treatments of luteinizing hormone-releasing hormone for inducing spermiation in American (Bufo americanus) and Gulf Coast (Bufo valliceps) toads.

    Science.gov (United States)

    Rowson, Angela D.; Obringer, Amy R.; Roth, Terri L.

    2001-01-01

    As many as 20% of all assessed amphibian species are threatened with extinction, and captive breeding programs are becoming important components of conservation strategies for this taxon. For some species, exogenous hormone administration has been integrated into breeding protocols to improve propagation. However, most treatments are administered by an intraperitoneal injection that can be associated with some risks. The general goal of this study was to identify a non-invasive method of applying luteinizing hormone-releasing hormone (LHRH), which reliably induces sperm release in toads. Specific objectives were to 1) test the spermiation response after topical application of different LHRH doses to the abdominal seat region, 2) evaluate the effects of adding the absorption enhancers dimethyl sulfoxide (DMSO), acetone, and glyceryl monocaprylate (GMC) to the LHRH, 3) assess the spermiation response after oral delivery of LHRH in a mealworm vehicle, and 4) compare sperm characteristics and spermiation responses to treatments in two different toad species. Male American (n = 9) and Gulf Coast (n = 7) toads were rotated systematically through a series of treatments. Urine was collected and evaluated for the presence of sperm at 0, 3, 7, 12, and 24 hours post-treatment. There were no statistical differences in spermiation induction or sperm characteristics between American and Gulf Coast toads after the treatments. Oral administration of 100 &mgr;g LHRH was occasionally successful in inducing spermiation, but results appeared largely unreliable. Ventral dermal application of 100 or 10 &mgr;g LHRH in 40% DMSO were more effective (P Zoo Biol 20:63-74, 2001. Copyright 2001 Wiley-Liss, Inc.

  9. Neutral current induced reactions in the Gargamelle experiment

    International Nuclear Information System (INIS)

    Doninck, W. van

    1976-07-01

    In the heavy liquid bubble chamber Gargamelle at CERN, 3 candidates are found for the pure leptonic neutral current process anti upsilonsub(μ)e - → anti upsilon sub(μ)e - . For the inclusive semileptonic reactions upsilon N → μ - X and anti upsilon N → μ + X the ratios of the neutral current to the charged current cross sections are measured to be Rsub(upsilon) = 0.25 +- 0.04 and Rsub(anti upsilon) = 0.56 +- 0.09. These inclusive results differ from the prediction of parity conserving models by more than 3 standard deviations. All three reactions are compatible with the Weinberg-Salam-model and a value of sin 2 THETAsub(ω) near 0.3. (BJ) [de

  10. Evaluation of antivenoms in the neutralization of hyperalgesia and edema induced by Bothrops jararaca and Bothrops asper snake venoms

    Directory of Open Access Journals (Sweden)

    Picolo G.

    2002-01-01

    Full Text Available Neutralization of hyperalgesia induced by Bothrops jararaca and B. asper venoms was studied in rats using bothropic antivenom produced at Instituto Butantan (AVIB, 1 ml neutralizes 5 mg B. jararaca venom and polyvalent antivenom produced at Instituto Clodomiro Picado (AVCP, 1 ml neutralizes 2.5 mg B. aspar venom. The intraplantar injection of B. jararaca and B. asper venoms caused hyperalgesia, which peaked 1 and 2 h after injection, respectively. Both venoms also induced edema with a similar time course. When neutralization assays involving the independent injection of venom and antivenom were performed, the hyperalgesia induced by B. jararaca venom was neutralized only when bothropic antivenom was administered iv 15 min before venom injection, whereas edema was neutralized when antivenom was injected 15 min or immediately before venom injection. On the other hand, polyvalent antivenom did not interfere with hyperalgesia or edema induced by B. asper venom, even when administered prior to envenomation. The lack of neutralization of hyperalgesia and edema induced by B. asper venom is not attributable to the absence of neutralizing antibodies in the antivenom, since neutralization was achieved in assays involving preincubation of venom and antivenom. Cross-neutralization of AVCP or AVIB against B. jararaca and B. asper venoms, respectively, was also evaluated. Only bothropic antivenom partially neutralized hyperalgesia induced by B. asper venom in preincubation experiments. The present data suggest that hyperalgesia and edema induced by Bothrops venoms are poorly neutralized by commercial antivenoms even when antibodies are administered immediately after envenomation.

  11. Atmospheric Pressure Plasma Induced Sterilization and Chemical Neutralization

    Science.gov (United States)

    Garate, Eusebio; Evans, Kirk; Gornostaeva, Olga; Alexeff, Igor; Lock Kang, Weng; Wood, Thomas K.

    1998-11-01

    We are studying chemical neutralization and surface decontamination using atmospheric pressure plasma discharges. The plasma is produced by corona discharge from an array of pins and a ground plane. The array is constructed so that various gases, like argon or helium, can be flowed past the pins where the discharge is initiated. The pin array can be biased using either DC, AC or pulsed discharges. Results indicate that the atmospheric plasma is effective in sterilizing surfaces with biological contaminants like E-coli and bacillus subtilus cells. Exposure times of less than four minutes in an air plasma result in a decrease in live colony counts by six orders of magnitude. Greater exposure times result in a decrease of live colony counts of up to ten orders of magnitude. The atmospheric pressure discharge is also effective in decomposing organic phosphate compounds that are simulants for chemical warfare agents. Details of the decomposition chemistry, by-product formation, and electrical energy consumption of the system will be discussed.

  12. Heat Shock Protein 70 Neutralizes Apoptosis-Inducing Factor

    Directory of Open Access Journals (Sweden)

    Guido Kroemer

    2001-01-01

    Full Text Available Programmed cell death (apoptosis is the physiological process responsible for the demise of superfluous, aged, damaged, mutated, and ectopic cells. Its normal function is essential both for embryonic development and for maintenance of adult tissue homeostasis. Deficient apoptosis participates in cancerogenesis, whereas excessive apoptosis leads to unwarranted cell loss accounting for disparate diseases including neurodegeneration and AIDS. One critical step in the process of apoptosis consists in the permeabilization of mitochondrial membranes, leading to the release of proteins which normally are secluded behind the outer mitochondrial membrane[1]. For example, cytochrome c, which is normally confined to the mitochondrial intermembrane space, is liberated from mitochondria and interacts with a cytosolic protein, Apaf-1, causing its oligomerization and constitution of the so-called apoptosome, a protein complex which activates a specific class of cysteine proteases, the caspases[2]. Another example concerns the so-called apoptosis-inducing factor (AIF, another mitochondrial intermembrane protein which can translocate to the nucleus where it induces chromatin condensation and DNA fragmentation[3].

  13. Laser-induced fluorescence of metal-atom impurities in a neutral beam

    International Nuclear Information System (INIS)

    Burrell, C.F.; Pyle, R.V.; Sabetimani, Z.; Schlachter, A.S.

    1984-10-01

    The need to limit impurities in fusion devices to low levels is well known. We have investigated, by the technique of laser-induced fluorescence, the concentration of heavy-metal atoms in a neutral beam caused by their evaporation from the hot filaments in a conventional high-current multifilament hydrogen-ion source

  14. Direct measurements of neutral density depletion by two-photon absorption laser-induced fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Aanesland, A.; Liard, L.; Leray, G.; Jolly, J.; Chabert, P.

    2007-01-01

    The ground state density of xenon atoms has been measured by spatially resolved laser-induced fluorescence spectroscopy with two-photon excitation in the diffusion chamber of a magnetized Helicon plasma. This technique allows the authors to directly measure the relative variations of the xenon atom density without any assumptions. A significant neutral gas density depletion was measured in the core of the magnetized plasma, in agreement with previous theoretical and experimental works. It was also found that the neutral gas density was depleted near the radial walls

  15. Transition probability of the 5971-A line in neutral uranium from collision-induced fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Gagne, J.M.; Mongeau, B.; Demers, Y.; Pianarosa, P.

    1981-01-01

    From collision-induced fluorescence spectroscopy measurements, we have determined the transition probability Aof the 5971-A transition in neutral uranium. Our value, A 5971 = (5.9 +- 1.8) x 10 5 sec -1 , is, within experimental error, in good agreement with the previous determination of Corliss, A 5971 = (7.3 +- 3.0) x 10 5 sec -1 [J. Res. Nat. Bur. Stand. Sect. A 80,1 (1976)

  16. Two Photon Absorption Laser Induced Fluorescence for Neutral Hydrogen Profile Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Scime, Earl E. [West Virginia Univ., Morgantown, WV (United States)

    2016-09-23

    The magnitude and spatial dependence of neutral density in magnetic confinement fusion experiments is a key physical parameter, particularly in the plasma edge. Modeling codes require precise measurements of the neutral density to calculate charge-exchange power losses and drag forces on rotating plasmas. However, direct measurements of the neutral density are problematic. In this work, we proposed to construct a laser-based diagnostic capable of providing spatially resolved measurements of the neutral density in the edge of plasma in the DIII-D tokamak. The diagnostic concept is based on two-photon absorption laser induced fluorescence (TALIF). By injecting two beams of 205 nm light (co or counter propagating), ground state hydrogen (or deuterium or tritium) can be excited from the n = 1 level to the n = 3 level at the location where the two beams intersect. Individually, the beams experience no absorption, and therefore have no difficulty penetrating even dense plasmas. After excitation, a fraction of the hydrogen atoms decay from the n = 3 level to the n = 2 level and emit photons at 656 nm (the Hα line). Calculations based on the results of previous TALIF experiments in magnetic fusion devices indicated that a laser pulse energy of approximately 3 mJ delivered in 5 ns would provide sufficient signal-to-noise for detection of the fluorescence. In collaboration with the DIII-D engineering staff and experts in plasma edge diagnostics for DIII-D from Oak Ridge National Laboratory (ORNL), WVU researchers designed a TALIF system capable of providing spatially resolved measurements of neutral deuterium densities in the DIII-D edge plasma. The laser systems were specified, purchased, and assembled at WVU. The TALIF system was tested on a low-power hydrogen discharge at WVU and the plan was to move the instrument to DIII-D for installation in collaboration with ORNL researchers. After budget cuts at DIII-D, the DIII-D facility declined to support

  17. Two Photon Absorption Laser Induced Fluorescence for Neutral Hydrogen Profile Measurements

    International Nuclear Information System (INIS)

    Scime, Earl E.

    2016-01-01

    The magnitude and spatial dependence of neutral density in magnetic confinement fusion experiments is a key physical parameter, particularly in the plasma edge. Modeling codes require precise measurements of the neutral density to calculate charge-exchange power losses and drag forces on rotating plasmas. However, direct measurements of the neutral density are problematic. In this work, we proposed to construct a laser-based diagnostic capable of providing spatially resolved measurements of the neutral density in the edge of plasma in the DIII-D tokamak. The diagnostic concept is based on two-photon absorption laser induced fluorescence (TALIF). By injecting two beams of 205 nm light (co or counter propagating), ground state hydrogen (or deuterium or tritium) can be excited from the n = 1 level to the n = 3 level at the location where the two beams intersect. Individually, the beams experience no absorption, and therefore have no difficulty penetrating even dense plasmas. After excitation, a fraction of the hydrogen atoms decay from the n = 3 level to the n = 2 level and emit photons at 656 nm (the H α line). Calculations based on the results of previous TALIF experiments in magnetic fusion devices indicated that a laser pulse energy of approximately 3 mJ delivered in 5 ns would provide sufficient signal-to-noise for detection of the fluorescence. In collaboration with the DIII-D engineering staff and experts in plasma edge diagnostics for DIII-D from Oak Ridge National Laboratory (ORNL), WVU researchers designed a TALIF system capable of providing spatially resolved measurements of neutral deuterium densities in the DIII-D edge plasma. The laser systems were specified, purchased, and assembled at WVU. The TALIF system was tested on a low-power hydrogen discharge at WVU and the plan was to move the instrument to DIII-D for installation in collaboration with ORNL researchers. After budget cuts at DIII-D, the DIII-D facility declined to support installation on their

  18. P53-dependent upregulation of neutral sphingomyelinase-2: role in doxorubicin-induced growth arrest.

    Science.gov (United States)

    Shamseddine, A A; Clarke, C J; Carroll, B; Airola, M V; Mohammed, S; Rella, A; Obeid, L M; Hannun, Y A

    2015-10-29

    Neutral sphingomyelinase-2 (nSMase2) is a ceramide-generating enzyme that has been implicated in growth arrest, apoptosis and exosome secretion. Although previous studies have reported transcriptional upregulation of nSMase2 in response to daunorubicin, through Sp1 and Sp3 transcription factors, the role of the DNA damage pathway in regulating nSMase2 remains unclear. In this study, we show that doxorubicin induces a dose-dependent induction of nSMase2 mRNA and protein with concomitant increases in nSMase activity and ceramide levels. Upregulation of nSMase2 was dependent on ATR, Chk1 and p53, thus placing it downstream of the DNA damage pathway. Moreover, overexpression of p53 was sufficient to transcriptionally induce nSMase2, without the need for DNA damage. DNA-binding mutants as well as acetylation mutants of p53 were unable to induce nSMase2, suggesting a role of nSMase2 in growth arrest. Moreover, knockdown of nSMase2 prevented doxorubicin-induced growth arrest. Finally, p53-induced nSMase2 upregulation appears to occur via a novel transcription start site upstream of exon 3. These results identify nSMase2 as a novel p53 target gene, regulated by the DNA damage pathway to induce cell growth arrest.

  19. Description-based reappraisal regulate the emotion induced by erotic and neutral images in a Chinese population.

    Science.gov (United States)

    Peng, Jiaxin; Qu, Chen; Gu, Ruolei; Luo, Yue-Jia

    2012-01-01

    Previous emotion-regulation research has shown that the late positive potential (LPP) is sensitive to the down-regulation of emotion; however, whether LPP is also sensitive to the up-regulation of emotion remains unclear. The present study examined the description-based reappraisal effects on the up-regulation of positive emotions induced by erotic and neutral images in a Chinese population. Self-reported ratings and event-related potential (ERP) were recorded when subjects viewed pleasant and neutral images, which were shown after either a neutral or positive description. Self-reported results showed that images following positive descriptions were rated as more pleasant compared to images following neutral descriptions. ERP results revealed that the P2, P3, and slow wave (SW) components were larger for erotic pictures than for neutral pictures, while the positive description condition yielded attenuated erotic image-induced P2, P3 and SW and increased SW induced by neutral images. The results demonstrated that description-based reappraisal, as a method of reappraisal, significantly modulates the emotional experience and ERP responses to erotic and neutral images.

  20. Description-based reappraisal regulate the emotion induced by erotic and neutral images in a Chinese population

    Directory of Open Access Journals (Sweden)

    Jiaxin ePeng

    2013-01-01

    Full Text Available Previous emotion-regulation research has shown that the late positive potential (LPP is sensitive to the down-regulation of emotion; however, whether LPP is also sensitive to the up-regulation of emotion remains unclear. The present study examined the description-based reappraisal effects on the up-regulation of positive emotions induced by erotic and neutral images in a Chinese population. Self-reported ratings and event-related potential (ERP were recorded when subjects viewed pleasant and neutral images, which were shown after either a neutral or positive description. Self-reported results showed that images following positive descriptions were rated as more pleasant compared to images following neutral descriptions. ERP results revealed that the P2, P3, and slow wave (SW components were larger for erotic pictures than for neutral pictures, while the positive description condition yielded attenuated erotic image-induced P2, P3 and SW and increased SW induced by neutral images. The results demonstrated that description-based reappraisal, as a method of reappraisal, significantly modulates the emotional experience and ERP responses to erotic and neutral images.

  1. Trichinella surveillance in black bears (Ursus americanus) from Oregon, USA.

    Science.gov (United States)

    Mortenson, J A; Kent, M L; Fowler, D R; Chomel, B B; Immell, D A

    2014-01-01

    We used serology and muscle digestion to test black bears (Ursus americanus) from western Oregon, USA, for Trichinella. Results indicate black bears in Oregon are not part of a sylvatic cycle for Trichinella, and risk of human exposure to Trichinella larvae from eating black bear meat from Oregon appears low.

  2. Genomovirus Genomes Recovered from Echinothrips americanus Sampled in Florida, USA

    Science.gov (United States)

    Kraberger, Simona; Polston, Jane E.; Capobianco, Heather M.; Alcalá-Briseño, Ricardo I.; Fontenele, Rafaela S.

    2017-01-01

    ABSTRACT Four genomovirus genomes were recovered from thrips (Echinothrips americanus) collected in Florida, USA. These represent four new species which are members of the Gemycircularvirus (n = 2), Gemyduguivirus (n = 1), and Gemykibivirus (n = 1) genera. This is the first record, to our knowledge, of genomoviruses associated with a phytophagous insect. PMID:28546499

  3. Laser Induced Fluorescence Spectroscopy of Neutral and Ionized Polycyclic Aromatic Hydrocarbons in the Cosmic Simulation Chamber

    Science.gov (United States)

    Bejaoui, Salma; Salama, Farid; Contreras, Cesar; Sciamma O'Brien, Ella; Foing, Bernard; Pascale, Ehrenfreund

    2015-01-01

    Polycyclic aromatic hydrocarbon (PAH) molecules are considered the best carriers to account for the ubiquitous infrared emission bands. PAHs have also been proposed as candidates to explain the diffuse interstellar bands (DIBs), a series of absorption features seen on the interstellar extinction curve and are plausible carriers for the extended red emission (ERE), a photoluminescent process associated with a wide variety of interstellar environments. Extensive efforts have been devoted over the past two decades to characterize the physical and chemical properties of PAH molecules and ions in space. Absorption spectra of PAH molecules and ions trapped in solid matrices have been compared to the DIBs. Absorption spectra of several cold, isolated gas-phase PAHs have also been measured under experimental conditions that mimic the interstellar conditions. The purpose of this study is to provide a new dimension to the existing spectroscopic database of neutral and single ionized PAHs that is largely based on absorption spectra by adding emission spectroscopy data. The measurements are based on the laser induced fluorescence (LIF) technique and are performed with the Pulsed Discharge Nozzle (PDN) of the COSmIC laboratory facility at NASA Ames laboratory. The PDN generates a plasma in a free supersonic jet expansion to simulate the physical and the chemical conditions in interstellar environments. We focus, here, on the fluorescence spectra of large neutral PAHs and their cations where there is a lack of fluorescence spectroscopy data. The astronomical implications of the data (e.g., ERE) are examined.

  4. Massively parallel sequencing and analysis of the Necator americanus transcriptome.

    Directory of Open Access Journals (Sweden)

    Cinzia Cantacessi

    2010-05-01

    Full Text Available The blood-feeding hookworm Necator americanus infects hundreds of millions of people worldwide. In order to elucidate fundamental molecular biological aspects of this hookworm, the transcriptome of the adult stage of Necator americanus was explored using next-generation sequencing and bioinformatic analyses.A total of 19,997 contigs were assembled from the sequence data; 6,771 of these contigs had known orthologues in the free-living nematode Caenorhabditis elegans, and most of them encoded proteins with WD40 repeats (10.6%, proteinase inhibitors (7.8% or calcium-binding EF-hand proteins (6.7%. Bioinformatic analyses inferred that the C. elegans homologues are involved mainly in biological pathways linked to ribosome biogenesis (70%, oxidative phosphorylation (63% and/or proteases (60%; most of these molecules were predicted to be involved in more than one biological pathway. Comparative analyses of the transcriptomes of N. americanus and the canine hookworm, Ancylostoma caninum, revealed qualitative and quantitative differences. For instance, proteinase inhibitors were inferred to be highly represented in the former species, whereas SCP/Tpx-1/Ag5/PR-1/Sc7 proteins ( = SCP/TAPS or Ancylostoma-secreted proteins were predominant in the latter. In N. americanus, essential molecules were predicted using a combination of orthology mapping and functional data available for C. elegans. Further analyses allowed the prioritization of 18 predicted drug targets which did not have homologues in the human host. These candidate targets were inferred to be linked to mitochondrial (e.g., processing proteins or amino acid metabolism (e.g., asparagine t-RNA synthetase.This study has provided detailed insights into the transcriptome of the adult stage of N. americanus and examines similarities and differences between this species and A. caninum. Future efforts should focus on comparative transcriptomic and proteomic investigations of the other predominant human

  5. Neutrino-induced neutral-current reaction cross sections for r-process nuclei

    CERN Document Server

    Langanke, K

    2002-01-01

    Neutrino-induced reactions play an important role during and after the r-process, if the latter occurs in an environment with extreme neutrino fluxes such as the neutrino-driven wind model or neutron star mergers. Recently we have evaluated the charged-current neutrino-nucleus cross sections relevant for r-process simulations. We extend our approach here to the neutral-current cross sections. Our tabulation considers neutron-rich nuclei with neutron numbers N=41-135 and charge numbers Z=21-82 and lists total as well as partial neutron spallation cross sections. The calculations have been performed within the random phase approximation considering multipole transitions with J<=3 and both parities. The supernova neutrino spectrum is described by a Fermi-Dirac distribution with various temperature parameters between T=2.8 MeV and T=10 MeV and with the degeneracy parameters alpha=0 and alpha=3.

  6. Holotoxin A1 Induces Apoptosis by Activating Acid Sphingomyelinase and Neutral Sphingomyelinase in K562 and Human Primary Leukemia Cells

    Directory of Open Access Journals (Sweden)

    Seong-Hoon Yun

    2018-04-01

    Full Text Available Marine triterpene glycosides are attractive candidates for the development of anticancer agents. Holotoxin A1 is a triterpene glycoside found in the edible sea cucumber, Apostichopus (Stichopus japonicus. We previously showed that cladoloside C2, the 25(26-dihydro derivative of holotoxin A1, induced apoptosis in human leukemia cells by activating ceramide synthase 6. Thus, we hypothesized that holotoxin A1, which is structurally similar to cladoloside C2, might induce apoptosis in human leukemia cells through the same molecular mechanism. In this paper, we compared holotoxin A1 and cladoloside C2 for killing potency and mechanism of action. We found that holotoxin A1 induced apoptosis more potently than cladoloside C2. Moreover, holotoxin A1 induced apoptosis in K562 cells by activating caspase-8 and caspase-3, but not by activating caspase-9. During holotoxin A1-induced apoptosis, acid sphingomyelinase (SMase and neutral SMase were activated in both K562 cells and human primary leukemia cells. Specifically inhibiting acid SMase and neutral SMаse with chemical inhibitors or siRNAs significantly inhibited holotoxin A1–induced apoptosis. These results indicated that holotoxin A1 might induce apoptosis by activating acid SMase and neutral SMase. In conclusion, holotoxin A1 represents a potential anticancer agent for treating leukemia. Moreover, the aglycone structure of marine triterpene glycosides might affect the mechanism involved in inducing apoptosis.

  7. Inactivated H7 Influenza Virus Vaccines Protect Mice despite Inducing Only Low Levels of Neutralizing Antibodies.

    Science.gov (United States)

    Kamal, Ram P; Blanchfield, Kristy; Belser, Jessica A; Music, Nedzad; Tzeng, Wen-Pin; Holiday, Crystal; Burroughs, Ashley; Sun, Xiangjie; Maines, Taronna R; Levine, Min Z; York, Ian A

    2017-10-15

    Avian influenza viruses of the H7 hemagglutinin (HA) subtype present a significant public health threat, as evidenced by the ongoing outbreak of human A(H7N9) infections in China. When evaluated by hemagglutination inhibition (HI) and microneutralization (MN) assays, H7 viruses and vaccines are found to induce lower level of neutralizing antibodies (nAb) than do their seasonal counterparts, making it difficult to develop and evaluate prepandemic vaccines. We have previously shown that purified recombinant H7 HA appear to be poorly immunogenic in that they induce low levels of HI and MN antibodies. In this study, we immunized mice with whole inactivated reverse genetics reassortant (RG) viruses expressing HA and neuraminidase (NA) from 3 different H7 viruses [A/Shanghai/2/2013(H7N9), A/Netherlands/219/2003(H7N7), and A/New York/107/2003(H7N2)] or with human A(H1N1)pdm09 (A/California/07/2009-like) or A(H3N2) (A/Perth16/2009) viruses. Mice produced equivalent titers of antibodies to all viruses as measured by enzyme-linked immunosorbent assay (ELISA). However, the antibody titers induced by H7 viruses were significantly lower when measured by HI and MN assays. Despite inducing very low levels of nAb, H7 vaccines conferred complete protection against homologous virus challenge in mice, and the serum antibodies directed against the HA head region were capable of mediating protection. The apparently low immunogenicity associated with H7 viruses and vaccines may be at least partly related to measuring antibody titers with the traditional HI and MN assays, which may not provide a true measure of protective immunity associated with H7 immunization. This study underscores the need for development of additional correlates of protection for prepandemic vaccines. IMPORTANCE H7 avian influenza viruses present a serious risk to human health. Preparedness efforts include development of prepandemic vaccines. For seasonal influenza viruses, protection is correlated with antibody

  8. Estimating Collisionally-Induced Escape Rates of Light Neutrals from Early Mars

    Science.gov (United States)

    Gacesa, M.; Zahnle, K. J.

    2016-12-01

    Collisions of atmospheric gases with hot oxygen atoms constitute an important non-thermal mechanism of escape of light atomic and molecular species at Mars. In this study, we present revised theoretical estimates of non-thermal escape rates of neutral O, H, He, and H2 based on recent atmospheric density profiles obtained from the NASA Mars Atmosphere and Volatile Evolution (MAVEN) mission and related theoretical models. As primary sources of hot oxygen, we consider dissociative recombination of O2+ and CO2+ molecular ions. We also consider hot oxygen atoms energized in primary and secondary collisions with energetic neutral atoms (ENAs) produced in charge-exchange of solar wind H+ and He+ ions with atmospheric gases1,2. Scattering of hot oxygen and atmospheric species of interest is modeled using fully-quantum reactive scattering formalism3. This approach allows us to construct distributions of vibrationally and rotationally excited states and predict the products' emission spectra. In addition, we estimate formation rates of excited, translationally hot hydroxyl molecules in the upper atmosphere of Mars. The escape rates are calculated from the kinetic energy distributions of the reaction products using an enhanced 1D model of the atmosphere for a range of orbital and solar parameters. Finally, by considering different scenarios, we estimate the influence of these escape mechanisms on the evolution of Mars's atmosphere throughout previous epochs and their impact on the atmospheric D/H ratio. M.G.'s research was supported by an appointment to the NASA Postdoctoral Program at the NASA Ames Research Center, administered by Universities Space Research Association under contract with NASA. 1N. Lewkow and V. Kharchenko, "Precipitation of Energetic Neutral Atoms and Escape Fluxes induced from the Mars Atmosphere", Astroph. J., 790, 98 (2014) 2M. Gacesa, N. Lewkow, and V. Kharchenko, "Non-thermal production and escape of OH from the upper atmosphere of Mars", arXiv:1607

  9. Precisely Molded Nanoparticle Displaying DENV-E Proteins Induces Robust Serotype-Specific Neutralizing Antibody Responses.

    Directory of Open Access Journals (Sweden)

    Stefan W Metz

    2016-10-01

    Full Text Available Dengue virus (DENV is the causative agent of dengue fever and dengue hemorrhagic fever. The virus is endemic in over 120 countries, causing over 350 million infections per year. Dengue vaccine development is challenging because of the need to induce simultaneous protection against four antigenically distinct DENV serotypes and evidence that, under some conditions, vaccination can enhance disease due to specific immunity to the virus. While several live-attenuated tetravalent dengue virus vaccines display partial efficacy, it has been challenging to induce balanced protective immunity to all 4 serotypes. Instead of using whole-virus formulations, we are exploring the potentials for a particulate subunit vaccine, based on DENV E-protein displayed on nanoparticles that have been precisely molded using Particle Replication in Non-wetting Template (PRINT technology. Here we describe immunization studies with a DENV2-nanoparticle vaccine candidate. The ectodomain of DENV2-E protein was expressed as a secreted recombinant protein (sRecE, purified and adsorbed to poly (lactic-co-glycolic acid (PLGA nanoparticles of different sizes and shape. We show that PRINT nanoparticle adsorbed sRecE without any adjuvant induces higher IgG titers and a more potent DENV2-specific neutralizing antibody response compared to the soluble sRecE protein alone. Antigen trafficking indicate that PRINT nanoparticle display of sRecE prolongs the bio-availability of the antigen in the draining lymph nodes by creating an antigen depot. Our results demonstrate that PRINT nanoparticles are a promising platform for delivering subunit vaccines against flaviviruses such as dengue and Zika.

  10. A Measurement of Neutrino-Induced Charged-Current Neutral Pion Production

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, Robert H. [Univ. of Colorado, Boulder, CO (United States)

    2010-01-01

    This work presents the first comprehensive measurement of neutrino-induced charged-current neutral pion production (CCπ0) off a nuclear target. The Mini Booster Neutrino Experiment (MiniBooNE) and Booster Neutrino Beam (BNB) are discussed in detail. MiniBooNE is a high-statistics (~ 1, 000, 000 interactions) low-energy (Evϵ 2 0.5 - 2.0 GeV) neutrino experiment located at Fermilab. The method for selecting and reconstructing CCπ0 events is presented. The π0 and μ- are fully reconstructed in the final state allowing for the measurement of, among other things, the neutrino energy. The total observable CCπ0 cross-section is presented as a function of neutrino energy, along with five differential cross-sections in terms of the final state kinematics and Q2. The results are combined to yield a flux-averaged total cross-section of <σ>Φ = (9.2 ± 0.3stat. ± 1.5syst.) × 10-39 cm2/CH2 at energy 965 MeV. These measurements will aid future neutrino experiments with the prediction of their neutrino interaction rates.

  11. Characterizing Peptide Neutral Losses Induced by Negative Electron-Transfer Dissociation (NETD)

    Science.gov (United States)

    Rumachik, Neil G.; McAlister, Graeme C.; Russell, Jason D.; Bailey, Derek J.; Wenger, Craig D.; Coon, Joshua J.

    2012-01-01

    We implemented negative electron-transfer dissociation (NETD) on a hybrid ion trap/Orbitrap mass spectrometer to conduct ion/ion reactions using peptide anions and radical reagent cations. In addition to sequence-informative ladders of a•- and x-type fragment ions, NETD generated intense neutral loss peaks corresponding to the entire or partial side-chain cleavage from amino acids constituting a given peptide. Thus, a critical step towards the characterization of this recently introduced fragmentation technique is a systematic study of synthetic peptides to identify common neutral losses and preferential fragmentation pathways. Examining 46 synthetic peptides with high mass accuracy and high resolution analysis permitted facile determination of the chemical composition of each neutral loss. We identified 19 unique neutral losses from 14 amino acids and three modified amino acids, and assessed the specificity and sensitivity of each neutral loss using a database of 1542 confidently identified peptides generated from NETD shotgun experiments employing high-pH separations and negative electrospray ionization. As residue-specific neutral losses indicate the presence of certain amino acids, we determined that many neutral losses have potential diagnostic utility. We envision this catalogue of neutral losses being incorporated into database search algorithms to improve peptide identification specificity and to further advance characterization of the acidic proteome. PMID:22290482

  12. Cross-neutralization of antibodies induced by vaccination with Purified Chick Embryo Cell Vaccine (PCECV) against different Lyssavirus species.

    Science.gov (United States)

    Malerczyk, Claudius; Freuling, Conrad; Gniel, Dieter; Giesen, Alexandra; Selhorst, Thomas; Müller, Thomas

    2014-01-01

    Rabies is a neglected zoonotic disease caused by viruses belonging to the genus lyssavirus. In endemic countries of Asia and Africa, where the majority of the estimated 60,000 human rabies deaths occur, it is mainly caused by the classical rabies virus (RABV) transmitted by dogs. Over the last decade new species within the genus lyssavirus have been identified. Meanwhile 15 (proposed or classified) species exist, including Australian bat lyssavirus (ABLV), European bat lyssavirus (EBLV-1 and -2), Duvenhage virus (DUVV), as well as Lagos bat virus (LBV) and Mokola virus (MOKV) and recently identified novel species like Bokeloh bat lyssavirus (BBLV), Ikoma bat lyssavirus (IKOV) or Lleida bat lyssavirus (LLBV). The majority of these lyssavirus species are found in bat reservoirs and some have caused human infection and deaths. Previous work has demonstrated that Purified Chick Embryo Cell Rabies Vaccine (PCECV) not only induces immune responses against classical RABV, but also elicits cross-neutralizing antibodies against ABLV, EBLV-1 and EBLV-2. Using the same serum samples as in our previous study, this study extension investigated cross-neutralizing activities of serum antibodies measured by rapid fluorescent focus inhibition test (RFFIT) against selected other non-classical lyssavirus species of interest, namely DUVV and BBLV, as well as MOKV and LBV. Antibodies developed after vaccination with PCECV have neutralizing capability against BBLV and DUVV in the same range as against ABLV and EBLV-1 and -2. As expected, for the phylogenetically more distant species LBV no cross-neutralizing activity was found. Interestingly, 15 of 94 serum samples (16%) with a positive neutralizing antibody titer against RABV displayed specific cross-neutralizing activity (65-fold lower than against RABV) against one specific MOKV strain (Ethiopia isolate), which was not seen against a different strain (Nigeria isolate). Cross-neutralizing activities partly correlate with the

  13. Measurement of muon neutrino and antineutrino induced single neutral pion production cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Colin E. [Yale Univ., New Haven, CT (United States)

    2011-05-01

    Elucidating the nature of neutrino oscillation continues to be a goal in the vanguard of the efforts of physics experiment. As neutrino oscillation searches seek an increasingly elusive signal, a thorough understanding of the possible backgrounds becomes ever more important. Measurements of neutrino-nucleus interaction cross sections are key to this understanding. Searches for νμ → νe oscillation - a channel that may yield insight into the vanishingly small mixing parameter θ13, CP violation, and the neutrino mass hierarchy - are particularly susceptible to contamination from neutral current single π0 (NC 1π0) production. Unfortunately, the available data concerning NC 1π0 production are limited in scope and statistics. Without satisfactory constraints, theoretical models of NC 1π0 production yield substantially differing predictions in the critical Eν ~ 1 GeV regime. Additional investigation of this interaction can ameliorate the current deficiencies. The Mini Booster Neutrino Experiment (MiniBooNE) is a short-baseline neutrino oscillation search operating at the Fermi National Accelerator Laboratory (Fermilab). While the oscillation search is the principal charge of the MiniBooNE collaboration, the extensive data (~ 106 neutrino events) offer a rich resource with which to conduct neutrino cross section measurements. This work concerns the measurement of both neutrino and antineutrino NC 1π0 production cross sections at MiniBooNE. The size of the event samples used in the analysis exceeds that of all other similar experiments combined by an order of magnitude. We present the first measurements of the absolute NC 1π0 cross section as well as the first differential cross sections in both neutrino and antineutrino mode. Specifically, we measure single differential cross sections with respect to pion momentum and pion angle. We find the

  14. Charging induced emission of neutral atoms from NaCl nanocube corners

    International Nuclear Information System (INIS)

    Ceresoli, Davide; Zykova-Timan, Tatyana; Tosatti, Erio

    2008-01-01

    Detachment of neutral cations/anions from solid alkali halides can in principle be provoked by donating/subtracting electrons to the surface of alkali halide crystals, but generally constitutes a very endothermic process. However, the amount of energy required for emission is smaller for atoms located in less favorable positions, such as surface steps and kinks. For a corner ion in an alkali halide cube the binding is the weakest, so it should be easier to remove that atom, once it is neutralized. We carried out first principles density functional calculations and simulations of neutral and charged NaCl nanocubes, to establish the energetics of extraction of neutralized corner ions. Following hole donation (electron removal) we find that detachment of neutral Cl corner atoms will require a limited energy of about 0.8 eV. Conversely, following the donation of an excess electron to the cube, a neutral Na atom is extractable from the corner at the lower cost of about 0.6 eV. Since the cube electron affinity level (close to that a NaCl(100) surface state, which we also determine) is estimated to lie about 1.8 eV below vacuum, the overall energy balance upon donation to the nanocube of a zero-energy electron from vacuum will be exothermic. The atomic and electronic structure of the NaCl(100) surface, and of the nanocube Na and Cl corner vacancies are obtained and analyzed as a byproduct

  15. Beam-induced pressure variations in a TFTR neutral-beam injector

    International Nuclear Information System (INIS)

    Willis, J.E.; Berkner, K.H.

    1981-10-01

    In neutral-beam injection systems either all or part of the gas flow into the neutralizer comes from the plasma source. When the beam is switched on, ions from the plasma source, which used to contribute to the gas flow, are converted to an energetic beam and are pumped away: hence reducing the gas input to the neutralizer. The large volume of the neutralizer and its high conductance damp out rapid changes; for example, when the gas to the source is first turned on, there is a 230 msec exponential rise time associated with pressure in the neutralizer. The neutralizer in turn acts as a source of gas to the first chamber and the first chamber to the second and so on. Beam dumps become additional sources of gas in the second chamber and target tank as gas molecules are collisionally desorbed from the surface of the dump. A simple analytical model (the equivalent of an electrical RC circuit) of the volumes and conductances of the system has been used to describe the pressure variations. The use of time dependent sources terms in the model gives an estimate of the desorption rate from the dumps and its time variation during a beam pulse

  16. X-ray induced DNA double strand break production and repair in mammalian cells as measured by neutral filter elution

    Energy Technology Data Exchange (ETDEWEB)

    Bradley, M O; Kohn, K W [National Institutes of Health, Bethesda, MD (USA)

    1979-10-01

    A neutral filter elution method was used for detecting DNA double strand breaks in mouse L1210 cells after X-ray. The assay detected the number of double strand breaks induced by as little as 1000 rad of X-ray. The rate of DNA elution through the filters under neutral conditions increased with X-ray dose. Certain conditions for deproteinization, pH, and filter type were shown to increase the assay's sensitivity. Hydrogen peroxide and Bleomycin also induced apparent DNA double strand breaks, although the ratios of double to single strand breaks varied from those produced by X-ray. The introduction of double strand cuts by HpA I restriction endonuclease in DNA lysed on filters resulted in a rapid rate of elution under neutral conditions, implying that the method can detect double strand breaks if they exist in the DNA. The eluted DNA banded with a double stranded DNA marker in cesium chloride. This evidence suggested that the assay detected DNA double strand breaks. L1210 cells were shown to rejoin most of the DNA double strand breaks induced by 5-10 krad of X-ray with a half-time of about 40 minutes. (author).

  17. Excitation of an instability by neutral particle ionization induced fluxes in the tokamak edge plasma

    International Nuclear Information System (INIS)

    Bachmann, P.; Sunder, D.

    1991-01-01

    Strong density and potential fluctuations in the edge plasma of toroidal nuclear fusion devices can lead to anomalously fast particle and energy transport. There are some reasons to assume the level of these fluctuations to be connected with neutral particles which enter the plasma by gas puffing or recycling processes. The influence of neutral particles on the behaviour of electrostatic drift modes was investigated. Using the ballooning transformation the excitation of dissipative drift waves in tokamak was studied taking ionization and charge exchange into consideration. Ionization driven drift wave turbulence was analyzed. The higher the neutral particle density is the more important the plasma-wall interaction and the less important the action of the limiter becomes. Instabilities localized in the edge plasma and far from the limiter can be one of the reasons of such a phenomenon. In the present paper we show that such an instability may exist. Usually the neutral particle density is large in the vicinity of the limiter and decreases rapidly with the distance from it. Plasma particles generated by ionization of these neutrals outside the limiter shadow, move along the magnetic field lines into a region without neutrals and diffuse slowly across the magnetic field. We solve the stability problem for modes with a perpendicular wave length that is much larger than the ion Larmor radius with electron temperature, and much smaller than the minor plasma radius. The excitation of such modes localized far from the limiter is investigated. A one-dimensional differential equation is derived in the cold ion approximation without taking shear and toroidal effects into consideration. In the case of low flow velocities a nearly aperiodic instability is found analytically. Its growth rate is proportional to the equilibrium plasma velocity at the boundary of the neutral particle's free region and to the inverse of the extension of this zone. This mode is localized in the edge

  18. Oral immunization with rotavirus VP7 expressed in transgenic potatoes induced high titers of mucosal neutralizing IgA

    International Nuclear Information System (INIS)

    Wu Yuzhang; Li Jintao; Mou Zhirong; Fei Lei; Ni Bing; Geng Miao; Jia Zhengcai; Zhou Wei; Zou Liyun; Tang Yan

    2003-01-01

    Rotaviruses (RV) are a common cause of severe diarrhea in young children, resulting in nearly one million deaths worldwide annually. Rotavirus VP7 was the rotavirus neutralizing protein. Previous study reported that VP7 DNA vaccine can induce high levels of IgG in mice but cannot protect mice against challenge (Choi, A.H., Basu, M., Rae, M.N., McNeal, M.M., Ward, R.L., 1998. Virology 250, 230-240). We found that rotavirus VP7 could maintain its neutralizing immunity when it was transformed into the potato genome. Mice immunized with the transformed tubers successfully elicited serum IgG and mucosal IgA specific for VP7. The mucosal IgA titer was as high as 1000, while serum IgG titer was only 600. Neutralizing assays indicated that IgA could neutralize rotavirus. These results indicate the potential usefulness of plants for production and delivery of edible rotavirus vaccines

  19. Neutralization of interleukin-17A delays progression of silica-induced lung inflammation and fibrosis in C57BL/6 mice

    International Nuclear Information System (INIS)

    Chen, Ying; Li, Cuiying; Weng, Dong; Song, Laiyu; Tang, Wen; Dai, Wujing; Yu, Ye; Liu, Fangwei; Zhao, Ming; Lu, Chunwei; Chen, Jie

    2014-01-01

    Silica exposure can cause lung inflammation and fibrosis, known as silicosis. Interleukin-17A (IL-17A) and Th17 cells play a pivotal role in controlling inflammatory diseases. However, the roles of IL-17A and Th17 cells in the progress of silica-induced inflammation and fibrosis are poorly understood. This study explored the effects of IL-17A on silica-induced inflammation and fibrosis. We used an anti-mouse IL-17A antibody to establish an IL-17A-neutralized mice model, and mice were exposed to silica to establish an experimental silicosis model. We showed that IL-17A neutralization delayed neutrophil accumulation and progression of silica-induced lung inflammation and fibrosis. IL-17A neutralization reduced the percentage of Th17 in CD4 + T cells, decreased IL-6 and IL-1β expression, and increased Tregs at an early phase of silica-induced inflammation. Neutralization of IL-17A delayed silica-induced Th1/Th2 immune and autoimmune responses. These results suggest that IL-17A neutralization alleviates early stage silica-induced lung inflammation and delays progression of silica-induced lung inflammation and fibrosis. Neutralization of IL-17A suppressed Th17 cell development by decreasing IL-6 and/or IL-1β and increased Tregs at an early phase of silica-induced inflammation. Neutralization of IL-17A also delayed the Th1/Th2 immune response during silica-induced lung inflammation and fibrosis. IL-17A may play a pivotal role in the early phase of silica-induced inflammation and may mediate the Th immune response to influence silica-induced lung inflammation and fibrosis in mice. - Highlights: • Neutralization of IL-17A alleviated silica-induced lung inflammation of early stage. • Neutralization of IL-17A decreased Th17 cells and increased Tregs. • IL-17A mediated the reciprocal relationship of Th17/Tregs by IL-6 and/or IL-1β. • Neutralization of IL-17A delayed silica-induced Th1/Th2 immune response. • Neutralization of IL-17A delayed silica-induced lung

  20. Neutralization of interleukin-17A delays progression of silica-induced lung inflammation and fibrosis in C57BL/6 mice

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Ying; Li, Cuiying [Division of Pneumoconiosis, School of Public Health, China Medical University, Shenyang, Liaoning (China); Weng, Dong [Division of Pneumoconiosis, School of Public Health, China Medical University, Shenyang, Liaoning (China); Clinical Translational Research Center, Shanghai Pulmonary Hospital, Tongji University School of Medicine, Shanghai (China); Song, Laiyu; Tang, Wen; Dai, Wujing; Yu, Ye; Liu, Fangwei; Zhao, Ming; Lu, Chunwei [Division of Pneumoconiosis, School of Public Health, China Medical University, Shenyang, Liaoning (China); Chen, Jie, E-mail: chenjie@mail.cmu.edu.cn [Division of Pneumoconiosis, School of Public Health, China Medical University, Shenyang, Liaoning (China)

    2014-02-15

    Silica exposure can cause lung inflammation and fibrosis, known as silicosis. Interleukin-17A (IL-17A) and Th17 cells play a pivotal role in controlling inflammatory diseases. However, the roles of IL-17A and Th17 cells in the progress of silica-induced inflammation and fibrosis are poorly understood. This study explored the effects of IL-17A on silica-induced inflammation and fibrosis. We used an anti-mouse IL-17A antibody to establish an IL-17A-neutralized mice model, and mice were exposed to silica to establish an experimental silicosis model. We showed that IL-17A neutralization delayed neutrophil accumulation and progression of silica-induced lung inflammation and fibrosis. IL-17A neutralization reduced the percentage of Th17 in CD4 + T cells, decreased IL-6 and IL-1β expression, and increased Tregs at an early phase of silica-induced inflammation. Neutralization of IL-17A delayed silica-induced Th1/Th2 immune and autoimmune responses. These results suggest that IL-17A neutralization alleviates early stage silica-induced lung inflammation and delays progression of silica-induced lung inflammation and fibrosis. Neutralization of IL-17A suppressed Th17 cell development by decreasing IL-6 and/or IL-1β and increased Tregs at an early phase of silica-induced inflammation. Neutralization of IL-17A also delayed the Th1/Th2 immune response during silica-induced lung inflammation and fibrosis. IL-17A may play a pivotal role in the early phase of silica-induced inflammation and may mediate the Th immune response to influence silica-induced lung inflammation and fibrosis in mice. - Highlights: • Neutralization of IL-17A alleviated silica-induced lung inflammation of early stage. • Neutralization of IL-17A decreased Th17 cells and increased Tregs. • IL-17A mediated the reciprocal relationship of Th17/Tregs by IL-6 and/or IL-1β. • Neutralization of IL-17A delayed silica-induced Th1/Th2 immune response. • Neutralization of IL-17A delayed silica-induced lung

  1. Novel adenoviral vector induces T-cell responses despite anti-adenoviral neutralizing antibodies in colorectal cancer patients.

    Science.gov (United States)

    Morse, Michael A; Chaudhry, Arvind; Gabitzsch, Elizabeth S; Hobeika, Amy C; Osada, Takuya; Clay, Timothy M; Amalfitano, Andrea; Burnett, Bruce K; Devi, Gayathri R; Hsu, David S; Xu, Younong; Balcaitis, Stephanie; Dua, Rajesh; Nguyen, Susan; Balint, Joseph P; Jones, Frank R; Lyerly, H Kim

    2013-08-01

    First-generation, E1-deleted adenovirus subtype 5 (Ad5)-based vectors, although promising platforms for use as cancer vaccines, are impeded in activity by naturally occurring or induced Ad-specific neutralizing antibodies. Ad5-based vectors with deletions of the E1 and the E2b regions (Ad5 [E1-, E2b-]), the latter encoding the DNA polymerase and the pre-terminal protein, by virtue of diminished late phase viral protein expression, were hypothesized to avoid immunological clearance and induce more potent immune responses against the encoded tumor antigen transgene in Ad-immune hosts. Indeed, multiple homologous immunizations with Ad5 [E1-, E2b-]-CEA(6D), encoding the tumor antigen carcinoembryonic antigen (CEA), induced CEA-specific cell-mediated immune (CMI) responses with antitumor activity in mice despite the presence of preexisting or induced Ad5-neutralizing antibody. In the present phase I/II study, cohorts of patients with advanced colorectal cancer were immunized with escalating doses of Ad5 [E1-, E2b-]-CEA(6D). CEA-specific CMI responses were observed despite the presence of preexisting Ad5 immunity in a majority (61.3 %) of patients. Importantly, there was minimal toxicity, and overall patient survival (48 % at 12 months) was similar regardless of preexisting Ad5 neutralizing antibody titers. The results demonstrate that, in cancer patients, the novel Ad5 [E1-, E2b-] gene delivery platform generates significant CMI responses to the tumor antigen CEA in the setting of both naturally acquired and immunization-induced Ad5-specific immunity.

  2. Study of the antineutrino-induced elastic semi-leptonic neutral current reaction

    International Nuclear Information System (INIS)

    Racca, C.

    1978-01-01

    A study of the elastic neutral current reaction antiνsub(μ)p→antiνsub(μ)p has been done using Gargamelle filled with propane and the antineutrino beam of the CERN P.S. The space-time structure of the weak neutral current is discussed, the predictions of various V-A models for the ratio of neutral to charged current elastic cross-sections Rsup(antiν) are given. The experimental set-up, the scanning criteria and the program of reconstruction are described. The background due to the contamination by the reaction np→np principally is studied. Cuts are defined to resorbe these backgrounds and corrections are made for other backgrounds and losses. The results are compared with those of the reaction antiνsub(μ)p→μ + n and the ratio Rsup(antiν) is calculated. An upper limit of this ratio is given and the results are discussed [fr

  3. Neutral-depletion-induced axially asymmetric density in a helicon source and imparted thrust

    Science.gov (United States)

    Takahashi, Kazunori; Takao, Yoshinori; Ando, Akira

    2016-02-01

    The high plasma density downstream of the source is observed to be sustained only for a few hundreds of microsecond at the initial phase of the discharge, when pulsing the radiofrequency power of a helicon plasma thruster. Measured relative density of argon neutrals inside the source implies that the neutrals are significantly depleted there. A position giving a maximum plasma density temporally moves to the upstream side of the source due to the neutral depletion and then the exhausted plasma density significantly decreases. The direct thrust measurement demonstrates that the higher thrust-to-power ratio is obtained by using only the initial phase of the high density plasma, compared with the steady-state operation.

  4. Hepatitis C Virus E1 and E2 Proteins Used as Separate Immunogens Induce Neutralizing Antibodies with Additive Properties.

    Directory of Open Access Journals (Sweden)

    Elodie Beaumont

    Full Text Available Various strategies involving the use of hepatitis C virus (HCV E1 and E2 envelope glycoproteins as immunogens have been developed for prophylactic vaccination against HCV. However, the ideal mode of processing and presenting these immunogens for effective vaccination has yet to be determined. We used our recently described vaccine candidate based on full-length HCV E1 or E2 glycoproteins fused to the heterologous hepatitis B virus S envelope protein to compare the use of the E1 and E2 proteins as separate immunogens with their use as the E1E2 heterodimer, in terms of immunogenetic potential and the capacity to induce neutralizing antibodies. The specific anti-E1 and anti-E2 antibody responses induced in animals immunized with vaccine particles harboring the heterodimer were profoundly impaired with respect to those in animals immunized with particles harboring E1 and E2 separately. Moreover, the anti-E1 and anti-E2 antibodies had additive neutralizing properties that increase the cross-neutralization of heterologous strains of various HCV genotypes, highlighting the importance of including both E1 and E2 in the vaccine for an effective vaccination strategy. Our study has important implications for the optimization of HCV vaccination strategies based on HCV envelope proteins, regardless of the platform used to present these proteins to the immune system.

  5. Neutralized ion beam modification of cellulose membranes for study of ion charge effect on ion-beam-induced DNA transfer

    Science.gov (United States)

    Prakrajang, K.; Sangwijit, K.; Anuntalabhochai, S.; Wanichapichart, P.; Yu, L. D.

    2012-02-01

    Low-energy ion beam biotechnology (IBBT) has recently been rapidly developed worldwide. Ion-beam-induced DNA transfer is one of the important applications of IBBT. However, mechanisms involved in this application are not yet well understood. In this study plasma-neutralized ion beam was applied to investigate ion charge effect on induction of DNA transfer. Argon ion beam at 7.5 keV was neutralized by RF-driven plasma in the beam path and then bombarded cellulose membranes which were used as the mimetic plant cell envelope. Electrical properties such as impedance and capacitance of the membranes were measured after the bombardment. An in vitro experiment on plasmid DNA transfer through the cellulose membrane was followed up. The results showed that the ion charge input played an important role in the impedance and capacitance changes which would affect DNA transfer. Generally speaking, neutral particle beam bombardment of biologic cells was more effective in inducing DNA transfer than charged ion beam bombardment.

  6. Human Monoclonal Antibodies against West Nile Virus Induced by Natural Infection Neutralize at a Postattachment Step

    NARCIS (Netherlands)

    Vogt, Matthew R.; Moesker, Bastiaan; Goudsmit, Jaap; Jongeneelen, Mandy; Austin, S. Kyle; Oliphant, Theodore; Nelson, Steevenson; Pierson, Theodore C.; Wilschut, Jan; Throsby, Mark; Diamond, Michael S.

    West Nile virus (WNV) is a neurotropic flavivirus that is now a primary cause of epidemic encephalitis in North America. Studies of mice have demonstrated that the humoral immune response against WNV limits primary infection and protects against a secondary challenge. The most-potent neutralizing

  7. Neutral Sphingomyelinase Behaviour in Hippocampus Neuroinflammation of MPTP-Induced Mouse Model of Parkinson’s Disease and in Embryonic Hippocampal Cells

    Directory of Open Access Journals (Sweden)

    Samuela Cataldi

    2017-01-01

    Full Text Available Neutral sphingomyelinase is known to be implicated in growth arrest, differentiation, proliferation, and apoptosis. Although previous studies have reported the involvement of neutral sphingomyelinase in hippocampus physiopathology, its behavior in the hippocampus during Parkinson’s disease remains undetected. In this study, we show an upregulation of inducible nitric oxide synthase and a downregulation of neutral sphingomyelinase in the hippocampus of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine- (MPTP- induced mouse model of Parkinson’s disease. Moreover, the stimulation of neutral sphingomyelinase activity with vitamin 1,25-dihydroxyvitamin D3 reduces specifically saturated fatty acid sphingomyelin by making sphingomyelin a less rigid molecule that might influence neurite plasticity. The possible biological relevance of the increase of neutral sphingomyelinase in Parkinson’s disease is discussed.

  8. Impurity induced neutralization of MeV energy protons in JET plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Gondhalekar, A [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Korotkov, A A [AF Ioffe Institute, Saint Petersburg (Russian Federation)

    1994-07-01

    A model elucidating the role of carbon and beryllium, the main impurities in JET plasmas, in neutralizing MeV energy protons, which arise during ICRF heating of deuterium plasmas in the hydrogen minority heating mode D(H), and from D-D fusion reactions, is presented. The model establishes charge transfer from hydrogen-like impurity ions to protons as the main process for neutralization. Calculations for deducing the proton energy distribution function from measured hydrogen flux are described. The validity of the model is tested by using it to described the measured flux in different conditions of plasma heating and fueling. Further, it is used to deduce the background thermal deuterium atom density at the plasma center. 9 refs., 6 figs.

  9. Estimation of neutral-beam-induced field reversal in MFTF by an approximate scaling law

    International Nuclear Information System (INIS)

    Shearer, J.W.

    1980-01-01

    Scaling rules are derived for field-reversed plasmas whose dimensions are common multiples of the ion gyroradius in the vacuum field. These rules are then applied to the tandem MFTF configuration, and it is shown that field reversal appears to be possible for neutral beam currents of the order of 150 amperes, provided that the electron temperature is at least 500 eV

  10. Vaccine-induced cross-genotype reactive neutralizing antibodies against hepatitis C virus

    DEFF Research Database (Denmark)

    Meunier, Jean-Christophe; Gottwein, Judith M; Houghton, Michael

    2011-01-01

    We detected cross-reactive neutralizing antibodies (NtAb) against hepatitis C virus (HCV) in chimpanzees vaccinated with HCV-1 (genotype 1a) recombinant E1/E2 envelope glycoproteins. Five vaccinated chimpanzees, protected following HCV-1 challenge, were initially studied using the heterologous H77......a, with limited reactivity against 2a and 3a. Our study provides encouragement for the development of a recombinant envelope-based vaccine against hepatitis C....

  11. Direct measurement of the concentration of metastable ions produced from neutral gas particles using laser-induced fluorescence

    Science.gov (United States)

    Chu, Feng; Skiff, Fred; Berumen, Jorge; Mattingly, Sean; Hood, Ryan

    2017-10-01

    Extensive information can be obtained on wave-particle interactions and wave fields by direct measurement of perturbed ion distribution functions using laser-induced fluorescence (LIF). For practical purposes, LIF is frequently performed on metastables that are produced from neutral gas particles and existing ions in other electronic states. We numerically simulate the ion velocity distribution measurement and wave-detection process using a Lagrangian model for the LIF signal. The results show that under circumstances where the metastable ion population is coming directly from the ionization of neutrals (as opposed to the excitation of ground-state ions), the velocity distribution will only faithfully represent processes which act on the ion dynamics in a time shorter than the metastable lifetime. Therefore, it is important to know the ratio of metastable population coming from neutrals to that from existing ions to correct the LIF measurements of plasma ion temperature and electrostatic waves. In this paper, we experimentally investigate the ratio of these two populations by externally launching an ion acoustic wave and comparing the wave amplitudes that are measured with LIF and a Langmuir probe using a lock-in amplifier. DE-FG02-99ER54543.

  12. Kinetic and HPV infection effects on cross-type neutralizing antibody and avidity responses induced by Cervarix®

    Science.gov (United States)

    Kemp, Troy J.; Safaeian, Mahboobeh; Hildesheim, Allan; Pan, Yuanji; Penrose, Kerri J.; Porras, Carolina; Schiller, John T.; Lowy, Douglas R.; Herrero, Rolando; Pinto, Ligia A.

    2012-01-01

    Background We previously demonstrated that Cervarix® elicits antibody responses against vaccine-related types for which clinical efficacy was demonstrated (HPV-31 and -45). Here, we evaluated the kinetics of neutralization titers and avidity of Cervarix®-induced antibodies up to 36 months of follow-up in unexposed and HPV infected women. Methods A subset of women who participated in the Cost Rica HPV-16/18 Vaccine Trial had pre- and post-vaccination sera tested for antibody responses to HPV-16, -18, -31, -45, and -58 using a pseudovirion-based neutralization assay, and HPV-16 antibody avidity using an HPV-16 L1 VLP (virus-like particle)-based ELISA developed in our laboratory. Results In uninfected women, neutralizing antibody titers did not reach significance until after the 3rd dose for HPV-31 (month 12, p=0.009) and HPV-45 (month 12, p=0.003), but then persisted up to month 36 (HPV-31, p=0.01; HPV-45, p=0.002). Individuals infected with HPV-16 or HPV-31 at enrollment developed a significantly higher median antibody response to the corresponding HPV type after one dose, but there was not a difference between median titers after three doses compared to the HPV negative group. Median HPV-16 antibody avidity and titer increased over time up to month 12; however, the HPV-16 avidity did not correlate well with HPV-16 neutralizing antibody titers at each time point examined, except for month 6. The median avidity levels were higher in HPV-16 infected women at month 1 (p=0.04) and lower in HPV-16 infected women at month 12 (p=0.006) compared to the HPV negative women. Conclusions The persistence of cross-neutralization titers at month 36 suggests cross-reactive antibody responses are likely to persist long-term and are not influenced by infection status at enrollment. However, the weak correlation between avidity and neutralization titers emphasizes the need for examining avidity in efficacy studies to determine if high avidity antibodies play a critical role in

  13. Neutral endopeptidase up-regulation in isolated human umbilical artery: involvement in desensitization of bradykinin-induced vasoconstrictor effects.

    Science.gov (United States)

    Pelorosso, Facundo Germán; Halperin, Ana Verónica; Palma, Alejandro Martín; Nowak, Wanda; Errasti, Andrea Emilse; Rothlin, Rodolfo Pedro

    2007-02-01

    Previous reports show that bradykinin B(2) receptors mediate contractile responses induced by bradykinin (BK) in human umbilical artery (HUA). However, although it has been reported that BK-induced responses can desensitize in several inflammatory models, the effects of prolonged in vitro incubation on BK-induced vasoconstriction in HUA have not been studied. In isolated HUA rings, BK-induced responses after a 5-h in vitro incubation showed a marked desensitization compared with responses at 2 h. Inhibition of either angiotensin-converting enzyme (ACE) or neutral endopeptidase (NEP), both BK-inactivating enzymes, failed to modify responses to BK at 2 h. After 5 h, ACE inhibition produced only a slight potentiation of BK-induced responses. In contrast, BK-induced vasoconstriction at 5 h was markedly potentiated by NEP inhibition. Moreover, NEP activity, measured by hydrolysis of its synthetic substrate (Z-Ala-Ala-Leu-p-nitroanilide), showed a 2.4-fold increase in 5-h incubated versus 2-h incubated tissues, which was completely reversed by cycloheximide (CHX) treatment. Furthermore, CHX significantly potentiated BK-induced responses, suggesting that NEP-mediated kininase activity increase at 5 h depends on de novo protein synthesis. In addition, under NEP inhibition, CHX treatment failed to produce an additional potentiation of BK-induced vasoconstriction. Still, NEP up-regulation was confirmed by Western blot, showing a 2.1-fold increase in immunoreactive NEP in 5-h incubated versus 2-h incubated HUA. In summary, the present study provides strong pharmacological evidence that NEP is up-regulated and plays a key role in desensitization of BK-induced vasoconstriction after prolonged in vitro incubation in HUA. Our results provide new insights into the possible mechanisms involved in BK-induced response desensitization during sustained inflammatory conditions.

  14. HYDROCEPHALUS IN THREE JUVENILE NORTH AMERICAN BLACK BEARS (URSUS AMERICANUS).

    Science.gov (United States)

    Ferguson, Sylvia H; Novak, Janelle; Hecht, Silke; Craig, Linden E

    2016-06-01

    Hydrocephalus has been reported in a variety of species, including the North American black bear ( Ursus americanus ). This report describes three cases of hydrocephalus in this species from wild bears aged 3-4 mo considered retrospectively from necropsy records of one institution. Clinical signs included cortical blindness and ataxia. Primary gross findings were doming of the skull, gyri compression and flattening, and lateral ventricle dilation. Two cases had severe bilateral ventricular dilation with loss of the septum pellucidum; atrophy of the surrounding corpus callosum; and bilateral periventricular tears involving the caudate nuclei, internal capsule, and adjacent cerebrum. Histologically, the cases with periventricular tearing had severe axonal loss and degeneration, malacia, hemorrhage, and variable periventricular astrocytosis. All cases were likely congenital, given the bears' age and lack of an apparent acquired obstruction.

  15. Tetranucleotide microsatellite loci from the black bear (Ursus americanus)

    Science.gov (United States)

    Sanderlin, J.S.; Faircloth, B.C.; Shamblin, B.; Conroy, M.J.

    2009-01-01

    We describe primers and polymerase chain reaction conditions to amplify 21 tetranucleotide microsatellite DNA loci in black bears (Ursus americanus). We tested primers using individuals from two populations, one each in Georgia and Florida. Among individuals from Georgia (n = 29), primer pairs yielded an average of 2.9 alleles (range, one to four) and an average observed heterozygosity (HO) of 0.50 (range, 0.00 to 0.79). Among individuals from Florida (n = 19), primer pairs yielded an average of 5.7 alleles (range, one to 14) and an HO of 0.55 (range, 0.00 to 1.00). A comparison of previously developed markers with individuals from Georgia suggests that bear populations in Georgia and Florida have reduced allelic diversity relative to other populations. ?? 2008 The Authors.

  16. Adenovirus Particles that Display the Plasmodium falciparum Circumsporozoite Protein NANP Repeat Induce Sporozoite-Neutralizing Antibodies in Mice

    Science.gov (United States)

    Palma, Christopher; Overstreet, Michael G.; Guedon, Jean-Marc; Hoiczyk, Egbert; Ward, Cameron; Karen, Kasey A.; Zavala, Fidel; Ketner, Gary

    2011-01-01

    Adenovirus particles can be engineered to display exogenous peptides on their surfaces by modification of viral capsid proteins, and particles that display pathogen-derived peptides can induce protective immunity. We constructed viable recombinant adenoviruses that display B-cell epitopes from the Plasmodium falciparum circumsporozoite protein (PfCSP) in the major adenovirus capsid protein, hexon. Recombinants induced high-titer antibodies against CSP when injected intraperitoneally into mice. Serum obtained from immunized mice recognized both recombinant PfCSP protein and P. falciparum sporozoites, and neutralized P. falciparum sporozoites in vitro. Replicating adenovirus vaccines have provided economical protection against adenovirus disease for over three decades. The recombinants described here may provide a path to an affordable malaria vaccine in the developing world. PMID:21199707

  17. Data on IL-10R neutralization-induced chronic colitis in Lipocalin 2 deficient mice on BALB/c background

    Directory of Open Access Journals (Sweden)

    Vishal Singh

    2017-04-01

    Full Text Available The data herein is related to the research article entitled “Microbiota-inducible Innate Immune, Siderophore Binding Protein Lipocalin 2 is Critical for Intestinal Homeostasis” (Singh et al., 2016 [1] where we have demonstrated that C57BL/6 Lipocalin 2 deficient mice (Lcn2KO developed chronic colitis upon anti-interleukin-10 receptor (αIL-10R monoclonal antibody administration. In the present article, we evaluated the susceptibility of BALB/c Lcn2KO mice and their WT littermates to the αIL-10R neutralization-induced chronic colitis. Our data showed that αIL-10R mAb-treated BALB/c Lcn2KO mice exhibited severe chronic colitis (i.e., splenomegaly, colomegaly, colonic pathology, and incidence of rectal prolapse when compared to WT mice.

  18. Epitope mapping and characterization of a novel CD4-induced human monoclonal antibody capable of neutralizing primary HIV-1 strains

    International Nuclear Information System (INIS)

    Xiang Shihua; Wang Liping; Abreu, Mariam; Huang, C.-C.; Kwong, Peter D.; Rosenberg, Eric; Robinson, James E.; Sodroski, Joseph

    2003-01-01

    Human immunodeficiency virus (HIV-1) enters target cells by binding its gp120 exterior envelope glycoprotein to CD4 and one of the chemokine receptors, CCR5 or CXCR4. CD4-induced (CD4i) antibodies bind gp120 more efficiently after CD4 binding and block the interaction with the chemokine receptor. Examples of CD4i antibodies are limited, and the prototypes of the CD4i antibodies exhibit only weak neutralizing activity against primary, clinical HIV-1 isolates. Here we report the identification of a novel antibody, E51, that exhibits CD4-induced binding to gp120 and neutralizes primary HIV-1 more efficiently than the prototypic CD4i antibodies. The E51 antibody blocks the interaction of gp120-CD4 complexes with CCR5 and binds to a highly conserved, basic gp120 element composed of the β19-strand and surrounding structures. Thus, on primary HIV-1 isolates, this gp120 region, which has been previously implicated in chemokine receptor binding, is accessible to a subset of CD4i antibodies

  19. Colonization of dodder, Cuscuta indecorans, by Ca. Liberibacter asiaticus and Ca. Liberibacter americanus

    Science.gov (United States)

    Huanglongbing, or citrus greening, threatens the global citrus industry. The presumptive pathogen, Candidatus Liberibacter asiaticus and Candidatus Liberibacter americanus can be transferred from citrus to more easily studied experimental hosts by using holoparasitic dodder plants. However the int...

  20. Lipoproteins/peptides are sepsis-inducing toxins from bacteria that can be neutralized by synthetic anti-endotoxin peptides.

    Science.gov (United States)

    Martinez de Tejada, Guillermo; Heinbockel, Lena; Ferrer-Espada, Raquel; Heine, Holger; Alexander, Christian; Bárcena-Varela, Sergio; Goldmann, Torsten; Correa, Wilmar; Wiesmüller, Karl-Heinz; Gisch, Nicolas; Sánchez-Gómez, Susana; Fukuoka, Satoshi; Schürholz, Tobias; Gutsmann, Thomas; Brandenburg, Klaus

    2015-09-22

    Sepsis, a life-threatening syndrome with increasing incidence worldwide, is triggered by an overwhelming inflammation induced by microbial toxins released into the bloodstream during infection. A well-known sepsis-inducing factor is the membrane constituent of Gram-negative bacteria, lipopolysaccharide (LPS), signalling via Toll-like receptor-4. Although sepsis is caused in more than 50% cases by Gram-positive and mycoplasma cells, the causative compounds are still poorly described. In contradicting investigations lipoproteins/-peptides (LP), lipoteichoic acids (LTA), and peptidoglycans (PGN), were made responsible for eliciting this pathology. Here, we used human mononuclear cells from healthy donors to determine the cytokine-inducing activity of various LPs from different bacterial origin, synthetic and natural, and compared their activity with that of natural LTA and PGN. We demonstrate that LP are the most potent non-LPS pro-inflammatory toxins of the bacterial cell walls, signalling via Toll-like receptor-2, not only in vitro, but also when inoculated into mice: A synthetic LP caused sepsis-related pathological symptoms in a dose-response manner. Additionally, these mice produced pro-inflammatory cytokines characteristic of a septic reaction. Importantly, the recently designed polypeptide Aspidasept(®) which has been proven to efficiently neutralize LPS in vivo, inhibited cytokines induced by the various non-LPS compounds protecting animals from the pro-inflammatory activity of synthetic LP.

  1. Diffuse traumatic axonal injury in mice induces complex behavioural alterations that are normalized by neutralization of interleukin-1β.

    Science.gov (United States)

    Ekmark-Lewén, Sara; Flygt, Johanna; Fridgeirsdottir, Gudrun A; Kiwanuka, Olivia; Hånell, Anders; Meyerson, Bengt J; Mir, Anis K; Gram, Hermann; Lewén, Anders; Clausen, Fredrik; Hillered, Lars; Marklund, Niklas

    2016-04-01

    Widespread traumatic axonal injury (TAI) results in brain network dysfunction, which commonly leads to persisting cognitive and behavioural impairments following traumatic brain injury (TBI). TBI induces a complex neuroinflammatory response, frequently located at sites of axonal pathology. The role of the pro-inflammatory cytokine interleukin (IL)-1β has not been established in TAI. An IL-1β-neutralizing or a control antibody was administered intraperitoneally at 30 min following central fluid percussion injury (cFPI), a mouse model of widespread TAI. Mice subjected to moderate cFPI (n = 41) were compared with sham-injured controls (n = 20) and untreated, naive mice (n = 9). The anti-IL-1β antibody reached the target brain regions in adequate therapeutic concentrations (up to ~30 μg/brain tissue) at 24 h post-injury in both cFPI (n = 5) and sham-injured (n = 3) mice, with lower concentrations at 72 h post-injury (up to ~18 μg/g brain tissue in three cFPI mice). Functional outcome was analysed with the multivariate concentric square field (MCSF) test at 2 and 9 days post-injury, and the Morris water maze (MWM) at 14-21 days post-injury. Following TAI, the IL-1β-neutralizing antibody resulted in an improved behavioural outcome, including normalized behavioural profiles in the MCSF test. The performance in the MWM probe (memory) trial was improved, although not in the learning trials. The IL-1β-neutralizing treatment did not influence cerebral ventricle size or the number of microglia/macrophages. These findings support the hypothesis that IL-1β is an important contributor to the processes causing complex cognitive and behavioural disturbances following TAI. © 2016 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

  2. Variable epitope libraries: new vaccine immunogens capable of inducing broad human immunodeficiency virus type 1-neutralizing antibody response.

    Science.gov (United States)

    Charles-Niño, Claudia; Pedroza-Roldan, Cesar; Viveros, Monica; Gevorkian, Goar; Manoutcharian, Karen

    2011-07-18

    The extreme antigenic variability of human immunodeficiency virus (HIV) leads to immune escape of the virus, representing a major challenge in the design of effective vaccine. We have developed a novel concept for immunogen construction based on introduction of massive mutations within the epitopes targeting antigenically variable pathogens and diseases. Previously, we showed that these immunogens carrying large combinatorial libraries of mutated epitope variants, termed as variable epitope libraries (VELs), induce potent, broad and long lasting CD8+IFN-γ+ T-cell response. Moreover, we demonstrated that these T cells recognize more than 50% of heavily mutated variants (5 out of 10 amino acid positions were mutated in each epitope variant) of HIV-1 gp120 V3 loop-derived cytotoxic T lymphocyte epitope (RGPGRAFVTI) in mice. The constructed VELs had complexities of 10000 and 12500 individual members, generated as plasmid DNA or as M13 phage display combinatorial libraries, respectively, and with structural composition RGPGXAXXXX or XGXGXAXVXI, where X is any of 20 natural amino acids. Here, we demonstrated that sera from mice immunized with these VELs are capable of neutralizing 5 out of 10 viral isolates from Tier 2 reference panel of subtype B envelope clones, including HIV-1 isolates which are known to be resistant to neutralization by several potent monoclonal antibodies, described previously. These data indicate the feasibility of the application of immunogens based on VEL concept as an alternative approach for the development of molecular vaccines against antigenically variable pathogens. Copyright © 2011 Elsevier Ltd. All rights reserved.

  3. Smoking and risk of treatment-induced neutralizing antibodies to interferon β-1a.

    Science.gov (United States)

    Hedström, Anna Karin; Ryner, Malin; Fink, Katarina; Fogdell-Hahn, Anna; Alfredsson, Lars; Olsson, Tomas; Hillert, Jan

    2014-04-01

    Neutralizing antibodies (NAbs) to interferon β (IFNβ) products that develop during treatment are associated with a loss of clinical efficacy. The aim of this study was to investigate the influence of smoking habits on the risk of developing NAbs to IFNβ, in the treatment of multiple sclerosis (MS). This report is based on 695 MS patients treated with IFNβ-1a, included in two Swedish case-control studies that collected information on smoking habits. Using logistic regression, the development of NAbs to IFNβ-1a among current smokers was compared with that of non-smokers, by calculating the odds ratio (OR) with a 95% confidence interval (CI). Current smokers showed an increased risk of developing NAbs to IFNβ-1a, compared with non-smokers (OR 1.9; 95% CI 1.3-2.8; p = 0.002). There were no gender differences. We observed no association between past smoking and the risk of developing NAbs to IFNβ-1a. The finding that current smokers have an increased risk of developing NAbs to IFNβ-1a has implications, both for the practical care and the treatment of MS; it also provides an interesting perspective of the lungs as an immune-reactive organ, reacting upon irritation.

  4. A Recombinant HAV Expressing a Neutralization Epitope of HEV Induces Immune Response against HAV and HEV in Mice.

    Science.gov (United States)

    Xiang, Kui; Kusov, Yuri; Ying, Guan; Yan, Wang; Shan, Yi; Jinyuan, Wu; Na, Yin; Yan, Zhou; Hongjun, Li; Maosheng, Sun

    2017-09-15

    Hepatitis A virus (HAV) and hepatitis E virus (HEV) are causative agents of acute viral hepatitis transmitted via the fecal-oral route. Both viruses place a heavy burden on the public health and economy of developing countries. To test the possibility that HAV could be used as an expression vector for the development of a combination vaccine against hepatitis A and E infections, recombinant HAV-HEp148 was created as a vector to express an HEV neutralization epitope (HEp148) located at aa 459-606 of the HEV capsid protein. The recombinant virus expressed the HEp148 protein in a partially dimerized state in HAV-susceptible cells. Immunization with the HAV-HEp148 virus induced a strong HAV- and HEV-specific immune response in mice. Thus, the present study demonstrates a novel approach to the development of a combined hepatitis A and E vaccine.

  5. New Parameterizations for Neutral and Ion-Induced Sulfuric Acid-Water Particle Formation in Nucleation and Kinetic Regimes

    Science.gov (United States)

    Määttänen, Anni; Merikanto, Joonas; Henschel, Henning; Duplissy, Jonathan; Makkonen, Risto; Ortega, Ismael K.; Vehkamäki, Hanna

    2018-01-01

    We have developed new parameterizations of electrically neutral homogeneous and ion-induced sulfuric acid-water particle formation for large ranges of environmental conditions, based on an improved model that has been validated against a particle formation rate data set produced by Cosmics Leaving OUtdoor Droplets (CLOUD) experiments at European Organization for Nuclear Research (CERN). The model uses a thermodynamically consistent version of the Classical Nucleation Theory normalized using quantum chemical data. Unlike the earlier parameterizations for H2SO4-H2O nucleation, the model is applicable to extreme dry conditions where the one-component sulfuric acid limit is approached. Parameterizations are presented for the critical cluster sulfuric acid mole fraction, the critical cluster radius, the total number of molecules in the critical cluster, and the particle formation rate. If the critical cluster contains only one sulfuric acid molecule, a simple formula for kinetic particle formation can be used: this threshold has also been parameterized. The parameterization for electrically neutral particle formation is valid for the following ranges: temperatures 165-400 K, sulfuric acid concentrations 104-1013 cm-3, and relative humidities 0.001-100%. The ion-induced particle formation parameterization is valid for temperatures 195-400 K, sulfuric acid concentrations 104-1016 cm-3, and relative humidities 10-5-100%. The new parameterizations are thus applicable for the full range of conditions in the Earth's atmosphere relevant for binary sulfuric acid-water particle formation, including both tropospheric and stratospheric conditions. They are also suitable for describing particle formation in the atmosphere of Venus.

  6. Elevated expression of protein biosynthesis genes in liver and muscle of hibernating black bears (Ursus americanus).

    Science.gov (United States)

    Fedorov, Vadim B; Goropashnaya, Anna V; Tøien, Øivind; Stewart, Nathan C; Gracey, Andrew Y; Chang, Celia; Qin, Shizhen; Pertea, Geo; Quackenbush, John; Showe, Louise C; Showe, Michael K; Boyer, Bert B; Barnes, Brian M

    2009-04-10

    We conducted a large-scale gene expression screen using the 3,200 cDNA probe microarray developed specifically for Ursus americanus to detect expression differences in liver and skeletal muscle that occur during winter hibernation compared with animals sampled during summer. The expression of 12 genes, including RNA binding protein motif 3 (Rbm3), that are mostly involved in protein biosynthesis, was induced during hibernation in both liver and muscle. The Gene Ontology and Gene Set Enrichment analysis consistently showed a highly significant enrichment of the protein biosynthesis category by overexpressed genes in both liver and skeletal muscle during hibernation. Coordinated induction in transcriptional level of genes involved in protein biosynthesis is a distinctive feature of the transcriptome in hibernating black bears. This finding implies induction of translation and suggests an adaptive mechanism that contributes to a unique ability to reduce muscle atrophy over prolonged periods of immobility during hibernation. Comparing expression profiles in bears to small mammalian hibernators shows a general trend during hibernation of transcriptional changes that include induction of genes involved in lipid metabolism and carbohydrate synthesis as well as depression of genes involved in the urea cycle and detoxification function in liver.

  7. A multi-subunit Chlamydia vaccine inducing neutralizing antibodies and strong IFN-γ(+) CMI responses protects against a genital infection in minipigs

    DEFF Research Database (Denmark)

    Bøje, Sarah; Olsen, Anja Weinreich; Erneholm, Karin

    2016-01-01

    Chlamydia is the most widespread sexually transmitted bacterial disease and a prophylactic vaccine is highly needed. Ideally, this vaccine is required to induce a combined response of Th1 cell-mediated immune (CMI) response in concert with neutralizing antibodies. Using a novel Göttingen minipig...... animal model, we evaluated the immunogenicity and efficacy of a multi-subunit vaccine formulated in the strong Th1-inducing adjuvant CAF01. We evaluated a mixture of two fusion proteins (Hirep1 and CTH93) designed to promote either neutralizing antibodies or cell-mediated immunity, respectively. Hirep1...

  8. A multi-subunit Chlamydia vaccine inducing neutralizing antibodies and strong IFN-γ(+) CMI responses protects against a genital infection in minipigs

    DEFF Research Database (Denmark)

    Bøje, Sarah; Olsen, Anja Weinreich; Erneholm, Karin

    2016-01-01

    Chlamydia is the most widespread sexually transmitted bacterial disease and a prophylactic vaccine is highly needed. Ideally, this vaccine is required to induce a combined response of Th1 cell-mediated immune (CMI) response in concert with neutralizing antibodies. Using a novel Göttingen minipig...... trachomatis SvD bacteria (UV-SvD/CAF01) or CAF01. The Hirep1+CTH93/CAF01 vaccine induced a strong CMI response against the vaccine antigens and high titers of antibodies, particularly against the VD4 region of MOMP. Sera from Hirep1+CTH93/CAF01 immunized pigs neutralized C. trachomatis SvD and SvF infectivity...

  9. Spatial memory in captive American black bears (Ursus americanus).

    Science.gov (United States)

    Zamisch, Valeria; Vonk, Jennifer

    2012-11-01

    The spatial memory and foraging strategies of four adult captive-born American black bears (Ursus americanus) were explored in four experiments using a simulated foraging task. In the first three experiments, each session consisted of two phases separated by a delay: During the exploration phase, subjects foraged among a set of baited and unbaited sites. During the delay, the same locations were rebaited and subjects were released again and allowed to search the sites (search phase). In Experiments 1a and 1b, different sites were baited each day and the interval between exploration and search was short (4 hr or 15 min). Subjects were not accurate at recovering the food items in either experiment. In Experiment 2, an "informed forager" paradigm was used in which one subject was given privileged knowledge about the location of the food during the exploration phase and was later released with an "uninformed" competitor during the search phase. The bears did not achieve above-chance recovery accuracy even in the presence of a competitor. In Experiment 3, the same two of four sites were continually baited and the bears were released simultaneously over a period of 20 days, with each baiting separated by 2 or 3 days. As a group, the bears' foraging accuracy with repeated baiting and longer intervals approached greater than chance accuracy. Results suggest some limitations on bears' use of spatial memory in captive environments, but reveal the potential for use of spatial memory over longer delays.

  10. Neutralizing effects of polyvalent antivenom on severe inflammatory response induced by Mesobuthus eupeus scorpion venom

    Directory of Open Access Journals (Sweden)

    Zayerzadeh1 E.

    2014-11-01

    Full Text Available This study evaluated the effects of Mesobuthus eupeus (Me scorpion venom on inflammatory response following injection. Additionally, the present study examined whether immunotherapy at specific time intervals would be effective on inflammatory response after Me venom inoculation. Animals were divided randomly into four groups: the first group received LD50 of venom and the second and third groups of animals; immunotherapy was performed in different time intervals and fourth group was considered as control group. Me venom inoculation is caused respiratory perturbations such as respiratory distress, respiration with open mouth, crepitation and finally respiratory arrest. Me inoculation is resulted in increased pro-inflammatory cytokines including TNF-α and IL-1. Venom injection also induced inflammatory response, characterized by significant increase in serum white blood cells and neutrophils at 30, 60 and 180 min following envenomation. Simultaneous administration of antivenom and venom prevented entirely clinical sings, cytokines and hematological changes. Delayed immunotherapy gradually ameliorated clinical features, cytokines changes and hematological abnormalities related to the envenomation. In conclusion, our observations indicate injection of M. eupeus scorpion venom induces severe inflammatory response which can be one of the causes of clinical complications. Additionally, immunotherapy beyond 1 h after envenomation with appropriate dose and route in victims with severe inflammatory response related to the M.eupeus scorpion envenomation is beneficial.

  11. Effects of ion-neutral chemical reactions on dynamics of lightning-induced electric field

    International Nuclear Information System (INIS)

    Hiraki, Yasutaka

    2009-01-01

    Secondary lightning phenomena in the upper atmosphere called sprites attract interest from the viewpoint of atomic-molecular and plasma physics. Lightning-induced electric field accelerates the ionospheric electrons up to tens of electron-volts, inducing electrical breakdown as well as strong optical emissions, through electron impact ionization of molecules. A large-scale structure of sprites is constructed by collective dynamics of filamentary streamer discharges in a rarified gas, which in turn is controlled by the distribution of the background electric field. In this paper, we firstly reanalyze the relationship between quasi-static field formation and local ion chemistry with first-order perturbation techniques. Secondly, we investigate with a full ion chemical model the effects of electron attachment to oxygen molecules on its density in moderate cases of undervoltage lightning electric fields rather than the cases of intense ionization in streamers. We estimate the minimum values that are provided by the chemical balance with electron detachment from negative ions. We also investigate the recovery timescale of the electron density and find that the scale (≥1 s) is occasionally much larger than the interval of each lightning stroke (∼10 ms). We suggest that the subsequent sprite event as well as the field formation could be well affected by the ghost of the primary event. We discuss further the negative ion chemistry triggered by electron attachment in the nighttime mesosphere.

  12. A DNA vaccine against chikungunya virus is protective in mice and induces neutralizing antibodies in mice and nonhuman primates.

    Directory of Open Access Journals (Sweden)

    Karthik Mallilankaraman

    2011-01-01

    Full Text Available Chikungunya virus (CHIKV is an emerging mosquito-borne alphavirus indigenous to tropical Africa and Asia. Acute illness is characterized by fever, arthralgias, conjunctivitis, rash, and sometimes arthritis. Relatively little is known about the antigenic targets for immunity, and no licensed vaccines or therapeutics are currently available for the pathogen. While the Aedes aegypti mosquito is its primary vector, recent evidence suggests that other carriers can transmit CHIKV thus raising concerns about its spread outside of natural endemic areas to new countries including the U.S. and Europe. Considering the potential for pandemic spread, understanding the development of immunity is paramount to the development of effective counter measures against CHIKV. In this study, we isolated a new CHIKV virus from an acutely infected human patient and developed a defined viral challenge stock in mice that allowed us to study viral pathogenesis and develop a viral neutralization assay. We then constructed a synthetic DNA vaccine delivered by in vivo electroporation (EP that expresses a component of the CHIKV envelope glycoprotein and used this model to evaluate its efficacy. Vaccination induced robust antigen-specific cellular and humoral immune responses, which individually were capable of providing protection against CHIKV challenge in mice. Furthermore, vaccine studies in rhesus macaques demonstrated induction of nAb responses, which mimicked those induced in convalescent human patient sera. These data suggest a protective role for nAb against CHIKV disease and support further study of envelope-based CHIKV DNA vaccines.

  13. Ebola virus-like particles produced in insect cells exhibit dendritic cell stimulating activity and induce neutralizing antibodies

    International Nuclear Information System (INIS)

    Ye Ling; Lin Jianguo; Sun Yuliang; Bennouna, Soumaya; Lo, Michael; Wu Qingyang; Bu Zhigao; Pulendran, Bali; Compans, Richard W.; Yang Chinglai

    2006-01-01

    Recombinant baculoviruses (rBV) expressing Ebola virus VP40 (rBV-VP40) or GP (rBV-GP) proteins were generated. Infection of Sf9 insect cells by rBV-VP40 led to assembly and budding of filamentous particles from the cell surface as shown by electron microscopy. Ebola virus-like particles (VLPs) were produced by coinfection of Sf9 cells with rBV-VP40 and rBV-GP, and incorporation of Ebola GP into VLPs was demonstrated by SDS-PAGE and Western blot analysis. Recombinant baculovirus infection of insect cells yielded high levels of VLPs, which were shown to stimulate cytokine secretion from human dendritic cells similar to VLPs produced in mammalian cells. The immunogenicity of Ebola VLPs produced in insect cells was evaluated by immunization of mice. Analysis of antibody responses showed that most of the GP-specific antibodies were of the IgG2a subtype, while no significant level of IgG1 subtype antibodies specific for GP was induced, indicating the induction of a Th1-biased immune response. Furthermore, sera from Ebola VLP immunized mice were able to block infection by Ebola GP pseudotyped HIV virus in a single round infection assay, indicating that a neutralizing antibody against the Ebola GP protein was induced. These results show that production of Ebola VLPs in insect cells using recombinant baculoviruses represents a promising approach for vaccine development against Ebola virus infection

  14. High-throughput pseudovirion-based neutralization assay for analysis of natural and vaccine-induced antibodies against human papillomaviruses.

    Directory of Open Access Journals (Sweden)

    Peter Sehr

    Full Text Available A highly sensitive, automated, purely add-on, high-throughput pseudovirion-based neutralization assay (HT-PBNA with excellent repeatability and run-to-run reproducibility was developed for human papillomavirus types (HPV 16, 18, 31, 45, 52, 58 and bovine papillomavirus type 1. Preparation of 384 well assay plates with serially diluted sera and the actual cell-based assay are separated in time, therefore batches of up to one hundred assay plates can be processed sequentially. A mean coefficient of variation (CV of 13% was obtained for anti-HPV 16 and HPV 18 titers for a standard serum tested in a total of 58 repeats on individual plates in seven independent runs. Natural antibody response was analyzed in 35 sera from patients with HPV 16 DNA positive cervical intraepithelial neoplasia grade 2+ lesions. The new HT-PBNA is based on Gaussia luciferase with increased sensitivity compared to the previously described manual PBNA (manPBNA based on secreted alkaline phosphatase as reporter. Titers obtained with HT-PBNA were generally higher than titers obtained with the manPBNA. A good linear correlation (R(2 = 0.7 was found between HT-PBNA titers and anti-HPV 16 L1 antibody-levels determined by a Luminex bead-based GST-capture assay for these 35 sera and a Kappa-value of 0.72, with only 3 discordant sera in the low titer range. In addition to natural low titer antibody responses the high sensitivity of the HT-PBNA also allows detection of cross-neutralizing antibodies induced by commercial HPV L1-vaccines and experimental L2-vaccines. When analyzing the WHO international standards for HPV 16 and 18 we determined an analytical sensitivity of 0.864 and 1.105 mIU, respectively.

  15. Inhibition of neutral sphingomyelinase decreases elevated levels of inducible nitric oxide synthase and apoptotic cell death in ocular hypertensive rats

    Energy Technology Data Exchange (ETDEWEB)

    Aslan, Mutay, E-mail: mutayaslan@akdeniz.edu.tr [Department of Medical Biochemistry, Akdeniz University Faculty of Medicine, Antalya (Turkey); Basaranlar, Goksun [Department of Biophysics, Akdeniz University Faculty of Medicine, Antalya (Turkey); Unal, Mustafa [Department of Ophthalmology, Akdeniz University Faculty of Medicine, Antalya (Turkey); Ciftcioglu, Akif [Department of Pathology, Akdeniz University Faculty of Medicine, Antalya (Turkey); Derin, Narin [Department of Biophysics, Akdeniz University Faculty of Medicine, Antalya (Turkey); Mutus, Bulent [Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario (Canada)

    2014-11-01

    Endoplasmic reticulum (ER) stress and excessive nitric oxide production via induction of inducible nitric oxide synthase (NOS2) have been implicated in the pathogenesis of neuronal retinal cell death in ocular hypertension. Neutral sphingomyelinase (N-SMase)/ceramide pathway can regulate NOS2 expression, hence this study determined the role of selective neutral sphingomyelinase (N-SMase) inhibition on retinal NOS2 levels, ER stress, apoptosis and visual evoked potentials (VEPs) in a rat model of elevated intraocular pressure (EIOP). NOS2 expression and retinal protein nitration were significantly greater in EIOP and significantly decreased with N-SMase inhibition. A significant increase was observed in retinal ER stress markers pPERK, CHOP and GRP78 in EIOP, which were not significantly altered by N-SMase inhibition. Retinal TUNEL staining showed increased apoptosis in all EIOP groups; however N-SMase inhibition significantly decreased the percent of apoptotic cells in EIOP. Caspase-3, -8 and -9 activities were significantly increased in EIOP and returned to baseline levels following N-SMase inhibition. Latencies of all VEP components were significantly prolonged in EIOP and shortened following N-SMase inhibition. Data confirm the role of nitrative injury in EIOP and highlight the protective effect of N-SMase inhibition in EIOP via down-regulation of NOS2 levels and nitrative stress. - Highlights: • Inhibition of N-SMase decreases NOS2 levels in ocular hypertension. • Inhibition of N-SMase decreases protein nitration in ocular hypertension. • Inhibition of N-SMase decreases caspase activation in ocular hypertension. • Inhibition of N-SMase decreases apoptosis in ocular hypertension.

  16. Bound states for a neutral particle analogous to a quantum dot induced by the non-inertial effects of the Fermi-Walker reference frame

    International Nuclear Information System (INIS)

    Bakke, Knut

    2010-01-01

    We study the appearance of bound states analogous to a quantum dot, proposed by Tan and Inkson (1996) , in the non-relativistic quantum dynamics of a neutral particle with permanent magnetic dipole moment induced by the non-inertial effects of the Fermi-Walker reference frame.

  17. The effect of modulators of radiation-induced G2 arrest on the repair of radiation-induced DNA damage detectable by neutral filter elution

    International Nuclear Information System (INIS)

    Rowley, R.; Kort, L.

    1988-01-01

    The influence of cycloheximide (50 μg/ml), caffeine (5 mM) and cordycepin (0.15 mM) on the repair of the damage detectable in DNA by neutral filter elution was determined. Chinese hamster ovary cells (CHO) were irradiated with X-ray doses of 20, 60 and 100 Gy then allowed to repair without drug treatment or in the presence of each drug for intervals up to 6 h. DNA damage repair proceeded in two phases. The fast component of the repair process (t 1/2 approx. 7 min) was not modified by drug treatment; the slow component (t 1/2 170 min) was unaffected by cycloheximide or cordycepin, but appeared to be inhibited by caffeine. It was concluded that: (a) the lesion which results in radiation-induced G 2 arrest is not the lesion which is detectable by neutral filter elution, and (b) the influence of caffeine on dsb repair is specific to caffeine and is not mediated by a reduction in the duration of G 2 arrest. (author)

  18. 125I-induced DNA double strand breaks: use in calibration of the neutral filter elution technique and comparison with X-ray induced breaks

    International Nuclear Information System (INIS)

    Radford, I.R.; Hodgson, G.S.

    1985-01-01

    The neutral filter elution assay, for measurement of DNA double strand breakage, has been calibrated using mouse L cells and Chinese hamster V79 cells labelled with [ 125 I]dUrd and then held at liquid nitrogen temperature to accumulate decays. The basis of the calibration is the observation that each 125 I decay, occurring in DNA, produces a DNA double strand break. Linear relationships between 125 I decays per cell and lethal lesions per cell (minus natural logarithm survival) and the level of elution, were found. Using the calibration data, it was calculated that the yield of DNA double strand breaks after X-irradiation of both cell types was from 6 to 9 x 10 -12 DNA double strand breaks per Gy per dalton of DNA, for doses greater than 6 Gy. Neutral filter elution and survival data for X-irradiated and 125 I-labelled cells suggested that the relationships between lethal lesions and DNA double strand breakage were significantly different for both cell types. An attempt was made to study the repair kinetics for 125 I-induced DNA double strand breaks, but was frustrated by the rapid DNA degradation which occurs in cells that have been killed by the freezing-thawing process. (author)

  19. Seroprevalence of Toxoplasma gondii from free-ranging black bears ( Ursus americanus ) from Florida.

    Science.gov (United States)

    Chambers, D L; Ulrey, W A; Guthrie, J M; Kwok, O C H; Cox, J J; Maehr, D S; Dubey, J P

    2012-06-01

    Toxoplasma gondii is a significant worldwide parasitic protozoan. In the present study, prevalence of antibodies of T. gondii was examined from 29 free-ranging black bears ( Ursus americanus ) from south-central Florida where the host species was listed as state threatened during this project. Overall T. gondii prevalence was found to be 44.8%, specifically 46.2% in male and 43.8% in female U. americanus , using a modified agglutination test (1:25 titer). Seroprevalence differences between sexes were not significant (P > 0.05). Results of the present study add supportive data to the growing body of evidence suggesting that U. americanus has one of the highest T. gondii seroprevalences among all known intermediate hosts. In addition, our data emphasize the importance of understanding parasitic disease dynamics from a conservation perspective.

  20. Morphological Dependence of Element Stoichiometry in the H. americanus Exoskeleton

    Science.gov (United States)

    Mergelsberg, S. T.; Ulrich, R. N.; Dove, P. M.

    2016-02-01

    The crustacean exoskeleton is a complex biocomposite of inorganic mineral and organic macromolecules that expresses highly divergent morphologies across different taxa. While the structures and compositions of the organic framework show complex links to environmental and developmental pressures, little is known about the mineral chemistry. Previous studies of the cuticle have assumed that magnesium, phosphorous, and other trace metals are largely contained in the inorganic mineral fraction. Due to analytical limitations of structural analyses and in situ spectroscopic methods, the stoichiometry of the organic and inorganic portions could not be resolved. For example, previous Raman and XRD studies conclude the higher concentrations of trace elements, such as P and Mg measured in reinforced structures, e.g. the claw and abdomen, are primarily determined by the mineral fraction. Using the American Lobster (Homarus americanus) as a model organism to establish relationships between body part function and cuticle composition, this study quantified the distributions of Mg and P in the mineral and organic fractions. The experiments were designed to dissolve the exoskeleton of 10 body parts using three types of solutions that were specific to extracting 1) the mineral phase, 2) protein, and 3) polysaccharide. Analysis of the solutions by ICP-OES shows the mineral phase contains magnesium and phosphorous at concentrations sufficient to support the formation of calcium-magnesium and phosphate minerals. The protein fraction of the body parts contains significantly more Mg and P than previously hypothesized, while the levels of P contained in the organic portion are fairly constant. The findings demonstrate the lobster cuticle contains a significant amount of non-mineralized P and Mg that is readily water-soluble in the protein component. However, for those body parts used for defense and food acquisition, such as the claw, the mineral component determines the overall

  1. A heterologous prime-boost Ebola virus vaccine regimen induces durable neutralizing antibody response and prevents Ebola virus-like particle entry in mice.

    Science.gov (United States)

    Chen, Tan; Li, Dapeng; Song, Yufeng; Yang, Xi; Liu, Qingwei; Jin, Xia; Zhou, Dongming; Huang, Zhong

    2017-09-01

    Ebola virus (EBOV) is one of the most virulent pathogens known to humans. Neutralizing antibodies play a major role in the protection against EBOV infections. Thus, an EBOV vaccine capable of inducing a long-lasting neutralizing antibody response is highly desirable. We report here that a heterologous prime-boost vaccine regimen can elicit durable EBOV-neutralizing antibody response in mice. A chimpanzee serotype 7 adenovirus expressing EBOV GP (denoted AdC7-GP) was generated and used for priming. A truncated version of EBOV GP1 protein (denoted GP1t) was produced at high levels in Drosophila S2 cells and used for boosting. Mouse immunization studies showed that the AdC7-GP prime/GP1t boost vaccine regimen was more potent in eliciting neutralizing antibodies than either the AdC7-GP or GP1t alone. Neutralizing antibodies induced by the heterologous prime-boost regimen sustained at high titers for at least 18 weeks after immunization. Significantly, in vivo challenge studies revealed that the entry of reporter EBOV-like particles was efficiently blocked in mice receiving the heterologous prime-boost regimen even at 18 weeks after the final dose of immunization. These results suggest that this novel AdC7-GP prime/GP1t boost regimen represents an EBOV vaccine approach capable of establishing long-term protection, and therefore warrants further development. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Neutralizing S1P inhibits intratumoral hypoxia, induces vascular remodelling and sensitizes to chemotherapy in prostate cancer

    Science.gov (United States)

    Ader, Isabelle; Golzio, Muriel; Andrieu, Guillaume; Zalvidea, Santiago; Richard, Sylvain; Sabbadini, Roger A.; Malavaud, Bernard; Cuvillier, Olivier

    2015-01-01

    Hypoxia promotes neovascularization, increased tumor growth, and therapeutic resistance. The transcription factor, hypoxia-inducible factor 1α (HIF-1α), has been reported as the master driver of adaptation to hypoxia. We previously identified the sphingosine kinase 1/sphingosine 1-phosphate (SphK1/S1P) pathway as a new modulator of HIF-1α under hypoxia. Taking advantage of a monoclonal antibody neutralizing extracellular S1P (sphingomab), we report that inhibition of S1P extracellular signaling blocks HIF-1α accumulation and activity in several cancer cell models exposed to hypoxia. In an orthotopic xenograft model of prostate cancer, we show that sphingomab reduces hypoxia and modifies vessel architecture within 5 days of treatment, leading to increased intratumoral blood perfusion. Supporting the notion that a transient vascular normalization of tumor vessels is the mechanism by which sphingomab exerts its effects, we demonstrate that administration of the antibody for 5 days before chemotherapy is more effective at local tumor control and metastatic dissemination than any other treatment scheduling. These findings validate sphingomab as a potential new normalization agent that could contribute to successful sensitization of hypoxic tumors to chemotherapy. PMID:25915662

  3. Determination of the D/T fuel mixture using two-photon laser induced fluorescence in combination with neutral beam injection

    International Nuclear Information System (INIS)

    Voslamber, D.; Mandl, W.

    1997-08-01

    Doppler-free two-photon induced fluorescence in the Lyman-α lines of H, D and T has been suggested previously as a local and isotope-selective diagnostic of the intrinsic neutral hydrogen densities in magnetically confined fusion plasmas. In the present paper it is shown that the diagnostic potential of this method is significantly increased if it is combined with neutral atom beams whose characteristics are such that efficient production of thermal ground state atoms via charge exchange reactions is achieved. Considerably deeper plasma regions than just the plasma edge can thus be probed and local, isotope-selective information is obtained on the more relevant ions rather than on the neutrals. Additional diagnostic possibilities, e.g. those arising from the spectroscopic investigation of the beam particles themselves, are also discussed. (author)

  4. Formalin-inactivated EV71 vaccine candidate induced cross-neutralizing antibody against subgenotypes B1, B4, B5 and C4A in adult volunteers.

    Directory of Open Access Journals (Sweden)

    Ai-Hsiang Chou

    Full Text Available Enterovirus 71 (EV71 has caused several epidemics of hand, foot and mouth diseases (HFMD in Asia. No effective EV71 vaccine is available. A randomized and open-label phase I clinical study registered with ClinicalTrials.gov #NCT01268787, aims to evaluate the safety, reactogenicity and immunogenicity of a formalin-inactivated EV71 vaccine candidate (EV71vac at 5- and 10-µg doses. In this study we report the cross-neutralizing antibody responses from each volunteer against different subgenotypes of EV71 and CVA16.Sixty eligible healthy adults were recruited and vaccinated. Blood samples were obtained on day 0, 21 and 42 and tested against B1, B4, B5, C2, C4A, C4B and CVA16 for cross-neutralizing antibody responses.The immunogenicity of both 5- and 10- µg doses were found to be very similar. Approximately 45% of the participants had 4-fold increase in Nt, but there was no further increase in Nt after the second dose. EV71vac induced very strong cross-neutralizing antibody responses in >85% of volunteers without pre-existing Nt against subgenotype B1, B5 and C4A. EV71vac elicited weak cross-neutralizing antibody responses (∼20% of participants against a C4B and Coxsackie virus A16. Over 90% of vaccinated volunteers did not develop cross-neutralizing antibody responses (Nt<8 against a C2 strain. EV71vac can boost and significantly enhance the neutralizing antibody responses in volunteers who already had pre-vaccination antibodies against EV71 and/or CVA16.EV71vac is efficient in eliciting cross-neutralizing antibody responses against EV71 subgenotypes B1, B4, B5, and C4A, and provides the rationale for its evaluation in phase II clinical trials.ClinicalTrials.gov NCT01268787.

  5. Antibodies to the A27 protein of vaccinia virus neutralize and protect against infection but represent a minor component of Dryvax vaccine--induced immunity.

    Science.gov (United States)

    He, Yong; Manischewitz, Jody; Meseda, Clement A; Merchlinsky, Michael; Vassell, Russell A; Sirota, Lev; Berkower, Ira; Golding, Hana; Weiss, Carol D

    2007-10-01

    The smallpox vaccine Dryvax, which consists of replication-competent vaccinia virus, elicits antibodies that play a major role in protection. Several vaccinia proteins generate neutralizing antibodies, but their importance for protection is unknown. We investigated the potency of antibodies to the A27 protein of the mature virion in neutralization and protection experiments and the contributions of A27 antibodies to Dryvax-induced immunity. Using a recombinant A27 protein (rA27), we confirmed that A27 contains neutralizing determinants and that vaccinia immune globulin (VIG) derived from Dryvax recipients contains reactivity to A27. However, VIG neutralization was not significantly reduced when A27 antibodies were removed, and antibodies elicited by an rA27 enhanced the protection conferred by VIG in passive transfer experiments. These findings demonstrate that A27 antibodies do not represent the major fraction of neutralizing activity in VIG and suggest that immunity may be augmented by vaccines and immune globulins that include strong antibody responses to A27.

  6. Seroprevalence of Toxoplasma gondii in American Black Bears ( Ursus americanus ) of the Central Appalachians, USA.

    Science.gov (United States)

    Cox, John J; Murphy, Sean M; Augustine, Ben C; Guthrie, Joseph M; Hast, John T; Maehr, Sutton C; McDermott, Joseph

    2017-07-01

    We assessed Toxoplasma gondii seroprevalence in 53 free-ranging American black bears ( Ursus americanus ) in the Central Appalachian Mountains, US. Seroprevalence was 62% with no difference between males and females or between juvenile and adult bears. Wildlife agencies should consider warnings in hunter education programs to reduce the chances for human infection from this source.

  7. Prevalence of Anaplasma phagocytophilum in North Carolina Eastern Black Bears ( Ursus americanus ).

    Science.gov (United States)

    Westmoreland, Lori S H; Stoskopf, Michael K; Maggi, Ricardo G

    2016-10-01

    We detected Anaplasma phagocytophilum by DNA amplification in whole blood from free-ranging, hunter-killed American black bears ( Ursus americanus ) from the east coast of North Carolina, US. Molecular prevalence for Anaplasma phagocytophilum was 3% from 68 black bears. No DNA of other Anaplasma or Ehrlichia spp. was identified.

  8. External morphology of the cycliophoran dwarf male: a comparative study of Symbion pandora and S. americanus

    DEFF Research Database (Denmark)

    Neves, Ricardo C.; Cunha, Marina R.; Funch, Peter

    2010-01-01

    the phylum was first described, the dwarf male has a remarkably complex bodyplan albeit its very small size (approx. 30–40 lm in length). Aiming to increase the knowledge on the gross morphology of the cycliophoran dwarf male, specimens from S. pandora and S. americanus were analyzed by scanning electron...... with the data currently available on other metazoan dwarf males....

  9. Study of strange particle production by neutral currents induced by 1 and 12 GeV neutrinos and antineutrinos

    International Nuclear Information System (INIS)

    Francois, T.L.B.

    1977-01-01

    Strange particles production by weak neutral currents was experimentally studied. The first result is a direct confirmation that neutral currents conserve strangeness (by an upper limit on ΔS=-1 production). The two other results, production rate of strange neutral particles and ratio of strange particles production for antineutrinos and neutrinos, prove that these particles are mainly produced in the final hadronic state rather than on strange sea-quarks and give an upper limit on the rate of this type of quark in the nucleon [fr

  10. A small antigenic determinant of the Chikungunya virus E2 protein is sufficient to induce neutralizing antibodies which are partially protective in mice.

    Directory of Open Access Journals (Sweden)

    Christopher Weber

    2015-04-01

    Full Text Available The mosquito-borne Chikungunya virus (CHIKV causes high fever and severe joint pain in humans. It is expected to spread in the future to Europe and has recently reached the USA due to globalization, climate change and vector switch. Despite this, little is known about the virus life cycle and, so far, there is no specific treatment or vaccination against Chikungunya infections. We aimed here to identify small antigenic determinants of the CHIKV E2 protein able to induce neutralizing immune responses.E2 enables attachment of the virus to target cells and a humoral immune response against E2 should protect from CHIKV infections. Seven recombinant proteins derived from E2 and consisting of linear and/or structural antigens were created, and were expressed in and purified from E. coli. BALB/c mice were vaccinated with these recombinant proteins and the mouse sera were screened for neutralizing antibodies. Whereas a linear N-terminally exposed peptide (L and surface-exposed parts of the E2 domain A (sA alone did not induce neutralizing antibodies, a construct containing domain B and a part of the β-ribbon (called B+ was sufficient to induce neutralizing antibodies. Furthermore, domain sA fused to B+ (sAB+ induced the highest amount of neutralizing antibodies. Therefore, the construct sAB+ was used to generate a recombinant modified vaccinia virus Ankara (MVA, MVA-CHIKV-sAB+. Mice were vaccinated with MVA-CHIKV-sAB+ and/or the recombinant protein sAB+ and were subsequently challenged with wild-type CHIKV. Whereas four vaccinations with MVA-CHIKV-sAB+ were not sufficient to protect mice from a CHIKV infection, protein vaccination with sAB+ markedly reduced the viral titers of vaccinated mice.The recombinant protein sAB+ contains important structural antigens for a neutralizing antibody response in mice and its formulation with appropriate adjuvants might lead to a future CHIKV vaccine.

  11. Cryptic speciation in the recently discovered American cycliophoran Symbion americanus; genetic structure and population expansion

    DEFF Research Database (Denmark)

    Baker, J.M.; Funch, Peter; Giribet, G.

    2007-01-01

      Symbion americanus was recently described as the second species in the phylum Cycliophora, living commensally on the American commercial lobster Homarus americanus. A previous genetic analysis of American and European populations of cycliophorans suggested that haplotype divergence in S....... americanus was much greater than in its European counterpart S. pandora. This study examined the population structure and demographics of 169 individuals thought to belong to S. americanus collected from lobsters over 13 North American localities (Nova Scotia, Canada to Maryland, USA) between October 2003...... and January 2006. Cytochrome c oxidase subunit I sequence data clearly suggested the presence of three cryptic lineages in a species complex, often co-occurring in the same lobster specimens. One of these lineages, named the "G" lineage, was represented by very few individuals and therefore was excluded from...

  12. Experimental results on one-pion neutral current reaction in all channels induced by antineutrinos at CERN PS

    CERN Document Server

    Erriquez, O; Bullock, F W; Cavalli, D; Engel, J P; Fogli-Muciaccia, M T; Gamba, D; Guyonnet, J L; Halsteinslid, A; Henderson, R C W; Huss, D; Jones, T W; Marzari-Chiesa, A; Myklebost, K; Natali, S; Nuzzo, S; Paty, M; Pullia, A; Riccati, L; Riester, J L; Rognebakke, A; Rollier, M; Romero, A

    1980-01-01

    Single pion production, in antineutrino-nucleon interactions via the neutral current, has been studied in the bubble chamber Gargamelle, filled with propane. Complete analysis of the secondaries, including pi /sup 0/'s, has allowed a detailed study of all channels. After background and nuclear corrections, results are obtained which can be interpreted in terms of isospin structure of the neutral weak current and of the Salam-Weinberg angle. Agreement is found with the currently accepted value of sin/sup 2/ theta /sub w/ and the data suggest an important contribution of I=/sup 3///sub 2/ final states. (11 refs).

  13. Phenomenology of neutral current interactions

    International Nuclear Information System (INIS)

    Sakurai, J.J.

    1978-01-01

    Neutral-current interactions are discussed within a rather general phenomenological framework without commitment to any particular theoretical model. Three points are kept in mind: what various experiments really measure; the performing of complete experiments to determine the neutral-current couplings; and the testing of models in an objective, emotionally uninvolved manner. The following topics are considered: neutrino-electron scattering, hadronic currents and models, neutrino-induced inclusive hadronic reactions, neutrino-induced exclusive hadronic reactions, and neutral-current phenomena without neutrinos. In conclusion, what has actually been learned about neutral-current interactions is summarized. 9 figures, 2 tables

  14. An alphavirus vector overcomes the presence of neutralizing antibodies and elevated numbers of Tregs to induce immune responses in humans with advanced cancer.

    Science.gov (United States)

    Morse, Michael A; Hobeika, Amy C; Osada, Takuya; Berglund, Peter; Hubby, Bolyn; Negri, Sarah; Niedzwiecki, Donna; Devi, Gayathri R; Burnett, Bruce K; Clay, Timothy M; Smith, Jonathan; Lyerly, H Kim

    2010-09-01

    Therapeutic anticancer vaccines are designed to boost patients' immune responses to tumors. One approach is to use a viral vector to deliver antigen to in situ DCs, which then activate tumor-specific T cell and antibody responses. However, vector-specific neutralizing antibodies and suppressive cell populations such as Tregs remain great challenges to the efficacy of this approach. We report here that an alphavirus vector, packaged in virus-like replicon particles (VRP) and capable of efficiently infecting DCs, could be repeatedly administered to patients with metastatic cancer expressing the tumor antigen carcinoembryonic antigen (CEA) and that it overcame high titers of neutralizing antibodies and elevated Treg levels to induce clinically relevant CEA-specific T cell and antibody responses. The CEA-specific antibodies mediated antibody-dependent cellular cytotoxicity against tumor cells from human colorectal cancer metastases. In addition, patients with CEA-specific T cell responses exhibited longer overall survival. These data suggest that VRP-based vectors can overcome the presence of neutralizing antibodies to break tolerance to self antigen and may be clinically useful for immunotherapy in the setting of tumor-induced immunosuppression.

  15. Epizootic shell disease in American lobsters Homarus americanus in southern New England: past, present and future.

    Science.gov (United States)

    Castro, Kathleen M; Cobb, J Stanley; Gomez-Chiarri, Marta; Tlusty, Michael

    2012-08-27

    The emergence of epizootic shell disease in American lobsters Homarus americanus in the southern New England area, USA, has presented many new challenges to understanding the interface between disease and fisheries management. This paper examines past knowledge of shell disease, supplements this with the new knowledge generated through a special New England Lobster Shell Disease Initiative completed in 2011, and suggests how epidemiological tools can be used to elucidate the interactions between fisheries management and disease.

  16. Effect of confinement and starvation on stress parameters in the American lobster (Homarus americanus

    Directory of Open Access Journals (Sweden)

    Edo D'Agaro

    2014-12-01

    Full Text Available The American lobster (Homarus americanus is one of the most important crustacean resources in North America. In Italy and Europe, this fishery product is available throughout the year and it has a high and increasing commercial demand. American lobsters are traditionally marketed live and stocked, without feed, in temperature controlled recirculating systems for several weeks before being sold in the market places. The current Italian legislation does not fix a maximum length of time for the crustacean confinement and specific welfare requirements. In the present research, a 4-week experiment was carried out using 42 adult H. americanus reared in 4 recirculating aquaculture tanks. After one month of confinement, mean glucose, protein and total haemocyte count levels in the hemolymph of H. americanus were stable and similar (P>0.05 to the values observed at the beginning of the experiment. Results of the proximate analysis of the abdominal muscles of H. americanus showed no significant differences in concentrations of crude protein, lipid and ash during the trial. At the end of the experiment, the sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blotting analysis revealed a marked degradation of the muscle myofibrillar proteins. A number of fragments, possibly from myosin, were evident in the range between 50 and 220 kDa between time t0 and t28. Results of this study show that the main hemolymphatic variables and degradation analysis of the muscle myofibrillar proteins can be used as sensitive indicators of the crustacean stress response to confinement and starvation.

  17. Neutral currents

    International Nuclear Information System (INIS)

    Paschos, E.A.

    1977-01-01

    It is stated that over the past few years considerable progress has been made in the field of weak interactions. The existence of neutral currents involving leptons and hadrons has been established and some of the questions concerning their detailed structure have been answered. This imposes constraints on the gauge theories and has eliminated large classes of models. New questions have also been raised, one of which concerns the conservation laws obeyed by neutral currents. The wide range of investigations is impressive and is expected to continue with new results from particle, nuclear, and atomic physics. Headings include - various aspects of a gauge theory (choice of group, the symmetry breaking scheme, representation assignments for fermion fields); space-time structure; isospin structure; leptonic neutral currents; and atomic experiments. (U.K.)

  18. Neutral currents

    International Nuclear Information System (INIS)

    Aubert, B.

    1994-11-01

    The evidence for the existence of weak neutral current has been a very controverted topics in the early 1970's, as well as the muon did in the 1930's. The history is very rich considering the evolution of the experimental techniques in high energy particle physics. The history of the discovery and the study of weak neutral current is reviewed. Later the quest of the intermediate vector boson continues with the decision of the community to build a large proton antiproton collider. (K.A.). 14 refs., 1 fig

  19. The Effect of Induced Antibodies with Respect to Neutralization, Clearance Rate and Functional Activity in a Rabbit/Infliximab Model

    DEFF Research Database (Denmark)

    Henriksen, Maiken Lumby; Søgaard Teisner, Ane; Kjeldsen, Jens

    2016-01-01

    BACKGROUND: Therapeutic antibodies are a developing field for treatment of an expanding number of inflammatory diseases, including Crohn's disease. Treatment with monoclonal antibodies is frequently hampered by development of anti-drug antibodies (ADAs) that may compromise the treatment. MATERIALS...... AND METHODS: We addressed this issue in a rabbit model of treatment with the anti-tumor-necrosis factor alpha (TNFα) antibody, infliximab (IFX). We developed an inhibition ELISA to selectively measure absolute concentrations of neutralizing antibodies and another ELISA for measuring the concentration...... of functional IFX in the circulation. RESULTS: We found that the concentration of functional IFX was inversely proportional to the concentration of neutralizing antibodies. CONCLUSION: Administration of IFX to rabbits showed diversity in immune responses/tolerance toward IFX, corresponding to responses observed...

  20. Evaluation of the neutral comet assay for detection of alpha-particle induced DNA-double-strand-breaks

    International Nuclear Information System (INIS)

    Hofbauer, Daniela

    2010-01-01

    Aim of this study was to differentiate DNA-double-strand-breaks from DNA-single-strand-breaks on a single cell level, using the comet assay after α- and γ-irradiation. Americium-241 was used as a alpha-irradiation-source, Caesium-137 was used for γ-irradiation. Because of technical problems with both the neutral and alkaline comet assay after irradiation of gastric cancer cells and human lymphocytes, no definite differentiation of DNA-damage was possible.

  1. pH-induced conformational change of the rotavirus VP4 spike: implications for cell entry and antibody neutralization.

    Science.gov (United States)

    Pesavento, Joseph B; Crawford, Sue E; Roberts, Ed; Estes, Mary K; Prasad, B V Venkataram

    2005-07-01

    The rotavirus spike protein, VP4, is a major determinant of infectivity and neutralization. Previously, we have shown that trypsin-enhanced infectivity of rotavirus involves a transformation of the VP4 spike from a flexible to a rigid bilobed structure. Here we show that at elevated pH the spike undergoes a drastic, irreversible conformational change and becomes stunted, with a pronounced trilobed appearance. These particles with altered spikes, at a normal pH of 7.5, despite the loss of infectivity and the ability to hemagglutinate, surprisingly exhibit sialic acid (SA)-independent cell binding in contrast to the SA-dependent cell binding exhibited by native virions. Remarkably, a neutralizing monoclonal antibody that remains bound to spikes throughout the pH changes (pH 7 to 11 and back to pH 7) completely prevents this conformational change, preserving the SA-dependent cell binding and hemagglutinating functions of the virion. A hypothesis that emerges from the present study is that high-pH treatment triggers a conformational change that mimics a post-SA-attachment step to expose an epitope recognized by a downstream receptor in the rotavirus cell entry process. This process involves sequential interactions with multiple receptors, and the mechanism by which the antibody neutralizes is by preventing this conformational change.

  2. Antibody induced by immunization with the Jeryl Lynn mumps vaccine strain effectively neutralizes a heterologous wild-type mumps virus associated with a large outbreak.

    Science.gov (United States)

    Rubin, Steven A; Qi, Li; Audet, Susette A; Sullivan, Bradley; Carbone, Kathryn M; Bellini, William J; Rota, Paul A; Sirota, Lev; Beeler, Judy

    2008-08-15

    Recent mumps outbreaks in older vaccinated populations were caused primarily by genotype G viruses, which are phylogenetically distinct from the genotype A vaccine strains used in the countries affected by the outbreaks. This finding suggests that genotype A vaccine strains could have reduced efficacy against heterologous mumps viruses. The remote history of vaccination also suggests that waning immunity could have contributed to susceptibility. To examine these issues, we obtained consecutive serum samples from children at different intervals after vaccination and assayed the ability of these samples to neutralize the genotype A Jeryl Lynn mumps virus vaccine strain and a genotype G wild-type virus obtained during the mumps outbreak that occurred in the United States in 2006. Although the geometric mean neutralizing antibody titers against the genotype G virus were approximately one-half the titers measured against the vaccine strain, and although titers to both viruses decreased with time after vaccination, antibody induced by immunization with the Jeryl Lynn mumps vaccine strain effectively neutralized the outbreak-associated virus at all time points tested.

  3. Grizzly bears (Ursus arctos horribilis) and black bears (Ursus americanus) prevent trabecular bone loss during disuse (hibernation).

    Science.gov (United States)

    McGee-Lawrence, Meghan E; Wojda, Samantha J; Barlow, Lindsay N; Drummer, Thomas D; Castillo, Alesha B; Kennedy, Oran; Condon, Keith W; Auger, Janene; Black, Hal L; Nelson, O Lynne; Robbins, Charles T; Donahue, Seth W

    2009-12-01

    Disuse typically causes an imbalance in bone formation and bone resorption, leading to losses of cortical and trabecular bone. In contrast, bears maintain balanced intracortical remodeling and prevent cortical bone loss during disuse (hibernation). Trabecular bone, however, is more detrimentally affected than cortical bone in other animal models of disuse. Here we investigated the effects of hibernation on bone remodeling, architectural properties, and mineral density of grizzly bear (Ursus arctos horribilis) and black bear (Ursus americanus) trabecular bone in several skeletal locations. There were no differences in bone volume fraction or tissue mineral density between hibernating and active bears or between pre- and post-hibernation bears in the ilium, distal femur, or calcaneus. Though indices of cellular activity level (mineral apposition rate, osteoid thickness) decreased, trabecular bone resorption and formation indices remained balanced in hibernating grizzly bears. These data suggest that bears prevent bone loss during disuse by maintaining a balance between bone formation and bone resorption, which consequently preserves bone structure and strength. Further investigation of bone metabolism in hibernating bears may lead to the translation of mechanisms preventing disuse-induced bone loss in bears into novel treatments for osteoporosis.

  4. Cold-adapted digestive aspartic protease of the clawed lobsters Homarus americanus and Homarus gammarus: biochemical characterization.

    Science.gov (United States)

    Rojo, Liliana; García-Carreño, Fernando; de Los Angeles Navarrete del Toro, Maria

    2013-02-01

    Aspartic proteinases in the gastric fluid of clawed lobsters Homarus americanus and Homarus gammarus were isolated to homogeneity by single-step pepstatin-A affinity chromatography; such enzymes have been previously identified as cathepsin D-like enzymes based on their deduced amino acid sequence. Here, we describe their biochemical characteristics; the properties of the lobster enzymes were compared with those of its homolog, bovine cathepsin D, and found to be unique in a number of ways. The lobster enzymes demonstrated hydrolytic activity against synthetic and natural substrates at a wider range of pH; they were more temperature-sensitive, showed no changes in the K(M) value at 4°C, 10°C, and 25°C, and had 20-fold higher k(cat)/K(M) values than bovine enzyme. The bovine enzyme was temperature-dependent. We propose that both properties arose from an increase in molecular flexibility required to compensate for the reduction of reaction rates at low habitat temperatures. This is supported by the fast denaturation rates induced by temperature.

  5. Low-salinity stress in the American lobster, Homarus americanus, after chronic sublethal exposure to cadmium: Biochemical effects

    Energy Technology Data Exchange (ETDEWEB)

    Gould, E

    1980-01-01

    Lobsters (Homarus americanus) were exposed to cadmium (6 ..mu..g 1sup(-1), 30 days) in flowing seawater, then held for 7 days in aerated 'clean' seawater at either ambient (27 per mill) or low (17 per mill) salinity. Cadmium exposure alone (ambient salinity) induced a general elevation of enzyme activity (heart, antennal gland, and muscle MDH; heart LDH and GPI), despite the probability of some clearance of cadmium from body tissues during the 'clean' seawater holding period. Low-salinity alone (non-exposed lobsters) caused a decrease of enzyme activity (AAT, LDH, GPI, PK) in most tissues examined, except for tail muscle IDH, the activity of which was increased, and MDH, which was significantly elevated above ambient controls in all tissues except heart. Most low-salinity effects were observed in tail muscle, and most cadmium effects, in heart; low-salinity effects outnumbered cadmium stress by nine to four. In heart and tail muscle of cadmium-exposed lobsters held at low salinity, each of the two stresses apparently operated to nullify the other's effects. The most prominent single biochemical response to these sublethal stresses was the elevation of MDH activity. The ratio MDH:LDH gave the clearest indication of overall relative stress.

  6. Dengue virus specific IgY provides protection following lethal dengue virus challenge and is neutralizing in the absence of inducing antibody dependent enhancement.

    Directory of Open Access Journals (Sweden)

    Ashley L Fink

    2017-07-01

    Full Text Available Dengue hemorrhagic fever (DHF and dengue shock syndrome (DSS are severe disease manifestations that can occur following sequential infection with different dengue virus serotypes (DENV1-4. At present, there are no licensed therapies to treat DENV-induced disease. DHF and DSS are thought to be mediated by serotype cross-reactive antibodies that facilitate antibody-dependent enhancement (ADE by binding to viral antigens and then Fcγ receptors (FcγR on target myeloid cells. Using genetically engineered DENV-specific antibodies, it has been shown that the interaction between the Fc portion of serotype cross-reactive antibodies and FcγR is required to induce ADE. Additionally, it was demonstrated that these antibodies were as neutralizing as their non-modified variants, were incapable of inducing ADE, and were therapeutic following a lethal, antibody-enhanced infection. Therefore, we hypothesized that avian IgY, which do not interact with mammalian FcγR, would provide a novel therapy for DENV-induced disease. We demonstrate here that goose-derived anti-DENV2 IgY neutralized DENV2 and did not induce ADE in vitro. Anti-DENV2 IgY was also protective in vivo when administered 24 hours following a lethal DENV2 infection. We were also able to demonstrate via epitope mapping that both full-length and alternatively spliced anti-DENV2 IgY recognized different epitopes, including epitopes that have not been previously identified. These observations provide evidence for the potential therapeutic applications of goose-derived anti-DENV2 IgY.

  7. Dengue virus specific IgY provides protection following lethal dengue virus challenge and is neutralizing in the absence of inducing antibody dependent enhancement.

    Science.gov (United States)

    Fink, Ashley L; Williams, Katherine L; Harris, Eva; Alvine, Travis D; Henderson, Thomas; Schiltz, James; Nilles, Matthew L; Bradley, David S

    2017-07-01

    Dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS) are severe disease manifestations that can occur following sequential infection with different dengue virus serotypes (DENV1-4). At present, there are no licensed therapies to treat DENV-induced disease. DHF and DSS are thought to be mediated by serotype cross-reactive antibodies that facilitate antibody-dependent enhancement (ADE) by binding to viral antigens and then Fcγ receptors (FcγR) on target myeloid cells. Using genetically engineered DENV-specific antibodies, it has been shown that the interaction between the Fc portion of serotype cross-reactive antibodies and FcγR is required to induce ADE. Additionally, it was demonstrated that these antibodies were as neutralizing as their non-modified variants, were incapable of inducing ADE, and were therapeutic following a lethal, antibody-enhanced infection. Therefore, we hypothesized that avian IgY, which do not interact with mammalian FcγR, would provide a novel therapy for DENV-induced disease. We demonstrate here that goose-derived anti-DENV2 IgY neutralized DENV2 and did not induce ADE in vitro. Anti-DENV2 IgY was also protective in vivo when administered 24 hours following a lethal DENV2 infection. We were also able to demonstrate via epitope mapping that both full-length and alternatively spliced anti-DENV2 IgY recognized different epitopes, including epitopes that have not been previously identified. These observations provide evidence for the potential therapeutic applications of goose-derived anti-DENV2 IgY.

  8. Neutral escape at Mars induced by the precipitation of high-energy protons and hydrogen atoms of the solar wind origin

    Science.gov (United States)

    Shematovich, Valery I.

    2017-04-01

    One of the first surprises of the NASA MAVEN mission was the observation by the SWIA instrument of a tenuous population of protons with solar wind energies travelling anti-sunward near periapsis, at altitudes of 150-250 km (Halekas et al., 2015). While the penetration of solar wind protons to low altitude is not completely unexpected given previous Mars Express results, this population maintains exactly the same velocity as the solar wind observed. From previous studies it was known that some fraction of the solar wind can interact with the extended corona of Mars. By charge exchange with the neutral particles in this corona, some fraction of the incoming solar wind protons can gain an electron and become an energetic neutral hydrogen atom. Once neutral, these particles penetrate through the Martian induced magnetosphere with ease, with free access to the collisional atmosphere/ionosphere. The origin, kinetics and transport of the suprathermal O atoms in the transition region (from thermosphere to exosphere) of the Martian upper atmosphere due to the precipitation of the high-energy protons and hydrogen atoms are discussed. Kinetic energy distribution functions of suprathermal and superthermal (ENA) oxygen atoms formed in the Martian upper atmosphere were calculated using the kinetic Monte Carlo model (Shematovich et al., 2011, Shematovich, 2013) of the high-energy proton and hydrogen atom precipitation into the atmosphere. These functions allowed us: (a) to estimate the non-thermal escape rates of neutral oxygen from the Martian upper atmosphere, and (b) to compare with available MAVEN measurements of oxygen corona. Induced by precipitation the escape of hot oxygen atoms may become dominant under conditions of extreme solar events - solar flares and coronal mass ejections, - as it was shown by recent observations of the NASA MAVEN spacecraft (Jakosky et al., 2015). This work is supported by the RFBR project and by the Basic Research Program of the Praesidium of

  9. A regulatory hydrophobic area in the flexible joint region of plasminogen activator inhibitor-1, defined with fluorescent activity-neutralizing ligands. Ligand-induced serpin polymerization

    DEFF Research Database (Denmark)

    Egelund, R; Einholm, A P; Pedersen, K E

    2001-01-01

    by all tested nonfluorescent neutralizers, indicating that all neutralizers bind to a common hydrophobic area preferentially accessible in active PAI-1. Activity neutralization proceeded through two consecutive steps as follows: first step is conversion to forms displaying substrate behavior toward u......PA, and second step is to forms inert to uPA. With some neutralizers, the second step was associated with PAI-1 polymerization. Vitronectin reduced the susceptibility to the neutralizers. Changes in sensitivity to activity neutralization by point mutations were compatible with the various neutralizers having...

  10. Three-dimensional reconstruction of the musculature of various life cycle stages of the cycliophoran Symbion americanus

    DEFF Research Database (Denmark)

    Cardoso Neves, Ricardo; Kristensen, Reinhardt Møbjerg; Wanninger, Andreas Wilhelm Georg

    2009-01-01

    Cycliophora is a very recently described phylum of acoelomate metazoans with a complex life cycle and a phylogenetic position that has been under debate ever since its discovery in 1995. Symbion americanus, which lives attached to the mouthparts of the American lobster, Homarus americanus...

  11. H5N1 whole-virus vaccine induces neutralizing antibodies in humans which are protective in a mouse passive transfer model.

    Directory of Open Access Journals (Sweden)

    M Keith Howard

    Full Text Available BACKGROUND: Vero cell culture-derived whole-virus H5N1 vaccines have been extensively tested in clinical trials and consistently demonstrated to be safe and immunogenic; however, clinical efficacy is difficult to evaluate in the absence of wide-spread human disease. A lethal mouse model has been utilized which allows investigation of the protective efficacy of active vaccination or passive transfer of vaccine induced sera following lethal H5N1 challenge. METHODS: We used passive transfer of immune sera to investigate antibody-mediated protection elicited by a Vero cell-derived, non-adjuvanted inactivated whole-virus H5N1 vaccine. Mice were injected intravenously with H5N1 vaccine-induced rodent or human immune sera and subsequently challenged with a lethal dose of wild-type H5N1 virus. RESULTS: Passive transfer of H5N1 vaccine-induced mouse, guinea pig and human immune sera provided dose-dependent protection of recipient mice against lethal challenge with wild-type H5N1 virus. Protective dose fifty values for serum H5N1 neutralizing antibody titers were calculated to be ≤1∶11 for all immune sera, independently of source species. CONCLUSIONS: These data underpin the confidence that the Vero cell culture-derived, whole-virus H5N1 vaccine will be effective in a pandemic situation and support the use of neutralizing serum antibody titers as a correlate of protection for H5N1 vaccines.

  12. Adenovirus Particles that Display the Plasmodium falciparum Circumsporozoite Protein NANP Repeat Induce Sporozoite-Neutralizing Antibodies in Mice

    OpenAIRE

    Palma, Christopher; Overstreet, Michael G.; Guedon, Jean-Marc; Hoiczyk, Egbert; Ward, Cameron; Karen, Kasey A.; Zavala, Fidel; Ketner, Gary

    2011-01-01

    Adenovirus particles can be engineered to display exogenous peptides on their surfaces by modification of viral capsid proteins, and particles that display pathogen-derived peptides can induce protective immunity. We constructed viable recombinant adenoviruses that display B-cell epitopes from the Plasmodium falciparum circumsporozoite protein (PfCSP) in the major adenovirus capsid protein, hexon. Recombinants induced high-titer antibodies against CSP when injected intraperitoneally into mice...

  13. Laser-induced positive ion and neutral atom/molecule emissions from single-crystal CaHPO4 center dot 2H20: The role of electron-beam-induced defects

    International Nuclear Information System (INIS)

    Dawes, Mary L.; Hess, Wayne P.; Kawaguchi, Yuji; Langford, S C.; Dickinson, J. Tom

    1998-01-01

    We examine laser-induced ion and neutral emissions from single-crystal CaHPO4 center dot 2H2O (brushite), a wide-band-gap, hydrated inorganic single crystal, with 248-nm excimer laser radiation. Both laser-induced ion and neutral emissions are several orders magnitude higher following exposure to 2keV electrons at current densities of 200 uA/cm2 and doses of 1 C/cm2. In addition to intense Ca+ signals, electron-irradiated surfaces yield substantial CaO+, PO+, and P+ signals. As-grown and as-cleaved brushite show only weak neutral O2 and Ca emissions, whereas electron-irradiated surfaces yield enhanced O2, Ca, PO, PO2, and P emissions. Electron irradiation (i) significantly heats the sample, leading to thermal dehydration (CaHPO4 formation) and pyrolysis (Ca2P2O7 formation)and (ii) chemically reduces the surface via electron stimulated desorption. The thermal effects are accompanied by morphological changes, including recrystallization. Although complex, these changes lead to high defect densities, which are responsible for the dramatic enhancements in the observed laser desorption

  14. SURGICAL CORRECTION OF BILATERAL PATELLAR LUXATION IN AN AMERICAN BLACK BEAR CUB (URSUS AMERICANUS).

    Science.gov (United States)

    Bennett, Katarina R; Desmarchelier, Marion R; Bailey, Trina R

    2015-06-01

    A wild orphaned male American black bear cub ( Ursus americanus ) presented with hind limb gait abnormalities and was found to have bilateral grade 3 laterally luxating patellas. There were no other significant abnormalities detected on neurologic, radiographic, or hematologic examinations. The trochlear grooves were deepened with a chondroplasty, and the redundant soft tissues imbricated. There was a marked improvement in the bear's gait postoperatively, with an apparent full return to function. To the authors' knowledge, patellar luxation has not been reported in the Ursidae family, and the success in this case suggests that this technique may be used in large wild or captive carnivore cubs.

  15. Studies on endoparasites of the black bear (Ursus americanus) in the southeastern United States.

    Science.gov (United States)

    Crum, J M; Nettles, V F; Davidson, W R

    1978-04-01

    Examination of 53 black bears (Ursus americanus) from six states in the southeastern United States revealed at least 17 species of endoparasites, including Sarcocystis sp., Spirometra mansonoides (spargana), Macracanthorhynchus ingens, Ancylostoma caninum, Arthrocephalus lotoris, Baylisascaris transfuga, Capillaria aerophila, Capillaria putorii, Crenosoma sp., Cyathospirura sp., Dirofilaria immitis, Gnathostoma sp., Gongylonema pulchrum, microfilariae, Molineus barbatus, Physaloptera sp. and Strongyloides sp. Twelve of these represent new host records for black bear, and two are considered to be new species. Data are presented on prevalence, intensity and geographic distribution of each species. Pathologic effects were associated with infections of spargana of S. mansonoides and adults of C. aerophilia.

  16. Consumption of seeds of southwestern white pine (Pinus strobiformis) by Black Bear (Ursus americanus)

    Science.gov (United States)

    Mattson, David J.; Arundel, Terry A.

    2013-01-01

    We report a discovery of black bears (Ursus americanus) consuming seeds of southwestern white pine (Pinus strobiformis) on north slopes of the San Francisco Peaks near Flagstaff, Arizona, in high-elevation, mixed-species conifer forest. In one instance, a bear had obtained seeds from cones excavated from a larder horde made by a red squirrel (Tamiasciurus hudsonicus). Consumption of seeds of southwestern white pine by bears had not been previously documented. This discovery adds to the number of species of pine used by bears for food as well as the geographic range within which the behavior occurs.

  17. Chemosensitivity of walking legs of the lobster Homarus americanus: neurophysiological response spectrum and thresholds

    Energy Technology Data Exchange (ETDEWEB)

    Derby, C D; Atema, J

    1982-01-01

    Responses of chemoreceptors in the walking legs of the lobster Homarus americanus to 35 individual compounds and 3 mixtures (prey odours and extracts) were studied using extracellular recording techniques. Compared against a standard mussel (Mytilus edulis) extract, these receptors were most sensitive to the amino acids L-glutamate, hydroxy-L-proline, L-aspartate, L-arginine, glycine, taurine, and L-alanine, as well as such other compounds as ammonium chloride, betaine, and the tripeptide glutathione. Most of these excitants are among those compounds most prevalent in the prey of lobsters.

  18. Laser Induced Fluorescence (LIF) Measurements of Neutral (ArI) and singly-ionized (ArII) Argon in a LargeScale Helicon Plasma

    Science.gov (United States)

    Kelly, R. F.; Fisher, D. M.; Hatch, M. W.; Gilmore, M.; Dwyer, R. H.; Meany, K.; Zhang, Y.; Desjardins, T. R.

    2017-10-01

    In order to investigate the role of neutral dynamics in helicon discharges in the HelCat (Helicon-Cathode) plasma device at U. New Mexico, a Laser Induced Fluorescence (LIF) system has been developed. The LIF system is based on a >250 mW, tunable diode laser with a tuning range between 680 and 700nm. For neutral Argon, the laser pumps the metastable (2P3/20) 4s level to the (2P1/20) 4p level using 696. 7352 nm light. The fluorescence radiation from decay to the (2P1/20) 4s level at 772. 6333 nm is observed. For singly ionized Argon, the laser pumps the 3s23p4(3 P)3d level to the 3s23p4(3 P)4p level using 686.3162nm light. The fluorescence radiation from the decay to the 3s23p4(3 P)4s level is observed. The system design, and velocity measurements in the axial, azimuthal and radial directions for ArI, and in the axial direction for ArII will be presented. Supported by U.S. National Science Foundation Award 1500423.

  19. Neutral Particle Analyzer Vertically Scanning Measurements of MHD-induced Energetic Ion Redistribution or Loss in the National Spherical Torus Experiment

    Energy Technology Data Exchange (ETDEWEB)

    S.S. Medley, R. Andre, R.E. Bell, D.S. Darrow, C.W. Domier, E.D. Fredrickson, N.N. Gorelenkov, S.M. Kaye, B.P. LeBlanc, K.C. Lee, F.M. Levinton, D. Liu, N.C. Luhmann, Jr., J.E. Menard, H. Park, D. Stutman, A.L. Roquemore, K. Tritz, H. Yuh and the NSTX Team

    2007-11-15

    Observations of magneto-hydro-dynamic (MHD) induced redistribution or loss of energetic ions measured using the vertically scanning capability of the Neutral Particle Analyzer diagnostic on the National Spherical Torus Experiment (NSTX) are presented along with TRANSP and ORBIT code analysis of the results. Although redistribution or loss of energetic ions due to bursting fishbone-like and low-frequency (f ~ 10 kHz) kinktype MHD activity has been reported previously, the primary goal of this work is to study redistribution or loss due to continuous Alfvénic (f ~ 20 – 150 kHz) modes, a topic that heretofore has not been investigated in detail for NSTX plasmas. Initial indications are that the former drive energetic ion loss whereas the continuous Alfvénic modes only cause redistribution and the energetic ions remain confined.

  20. Neutral Particle Analyzer Vertically Scanning Measurements of MHD-induced Energetic Ion Redistribution or Loss in the National Spherical Torus Experiment

    International Nuclear Information System (INIS)

    Medley, S.S.; Andre, R.; Bell, R.E.; Darrow, D.S.; Domier, C.W.; Fredrickson, E.D.; Gorelenkov, N.N.; Kaye, S.M.; LeBlanc, B.P.; Lee, K.C.; Levinton, F.M.; Liu, D.; Luhmann, N.C. Jr.; Menard, J.E.; Park, H.; Stutman, D.; Roquemore, A.L.; Tritz, K.; Yuh, H

    2007-01-01

    Observations of magneto-hydro-dynamic (MHD) induced redistribution or loss of energetic ions measured using the vertically scanning capability of the Neutral Particle Analyzer diagnostic on the National Spherical Torus Experiment (NSTX) are presented along with TRANSP and ORBIT code analysis of the results. Although redistribution or loss of energetic ions due to bursting fishbone-like and low-frequency (f ∼ 10 kHz) kinktype MHD activity has been reported previously, the primary goal of this work is to study redistribution or loss due to continuous Alfvenic (f ∼ 20-150 kHz) modes, a topic that heretofore has not been investigated in detail for NSTX plasmas. Initial indications are that the former drive energetic ion loss whereas the continuous Alfvenic modes only cause redistribution and the energetic ions remain confined.

  1. Radiation induced environmental remediation of Cr(VI) heavy metal in aerated neutral solution under simulated industrial effluent

    Energy Technology Data Exchange (ETDEWEB)

    Djouider, Fathi; Aljohani, Mohammed S. [King Abdulaziz Univ., Jeddah (Saudi Arabia). Nuclear Engineering Dept.

    2017-08-01

    Cr(VI) compounds are major water contaminants in most industrial effluents, due to their carcinogenicity, while Cr(III) is an important element for human metabolism. In a previous work, we showed that Cr(VI) was radiolytically reduced to Cr(III) by the CO{sub 2}{sup -.} radical at pH 3 N{sub 2}O-saturated solution in the presence of formate. Here in the present work, this removal was investigated by steady state irradiation and pulse radiolysis in aerated solution at neutral pH, which is close to natural conditions in most wastewaters, where the reducing agent is the superoxide radical anion O{sub 2}{sup -.} The degradation of Cr(VI) increased linearly with the absorbed dose and was significantly enhanced by the added formate but not by the radiolitically produced hydrogen peroxide at this pH. The rate constant for this reduction was found to be 1.28 x 10{sup 8} M{sup -1} s{sup -1} and the absorption spectrum of Cr(V) transient species was obtained. A partial recovery of Cr(VI) is observed over a period of ca. 5 ms following a second order kinetics with a rate constant 8.0 x 10{sup 6} M{sup -1} s{sup -1}. These outcomes suggest that gamma-irradiation of Cr(VI)-contaminated wastewaters and industrial effluents in presence of formate can be simple, effective and economical means for the remediation of this major contaminant.

  2. The neurosteroid pregnenolone sulfate neutralized the learning impairment induced by intrahippocampal nicotine in alcohol-drinking rats.

    Science.gov (United States)

    Martín-García, E; Pallarès, M

    2005-01-01

    The effects of intrahippocampal administration of nicotine and the neurosteroids pregnenolone sulfate and allopregnanolone on acquiring the lever-press response and extinction in a Skinner box were examined using voluntary alcohol-drinking rats. A free-choice drinking procedure that implies early availability of the alcoholic solution (10% ethanol v/v+3% glucose w/v in distilled water) was used. Alcohol and control rats were deprived of food and assigned at random to six groups. Each group received two consecutive intrahippocampal (dorsal CA1) injections immediately after 1-h of drinking ethanol and before the free lever-press response shaping and extinction session. The groups were: saline-saline; saline-pregnenolone sulfate (5 ng, 24 microM); saline-allopregnanolone (0.2 microg, 1.26 microM); nicotine (4.6 microg, 20 mM)-saline; nicotine-pregnenolone sulfate; nicotine-allopregnanolone. Blood alcohol concentrations were assessed the day before conditioning. The combination of the oral self-administration of ethanol and the intrahippocampal injection of nicotine deteriorated the ability to acquire the lever-press response. This effect was neutralized by intrahippocampal pregnenolone sulfate (negative modulator of the GABA(A) receptor complex), and it was not affected by intrahippocampal allopregnanolone (positive GABA receptor complex A modulator). Pregnenolone sulfate and allopregnanolone had no effects per se on lever-press acquisition, neither in alcohol-drinking rats nor in controls. Alcohol consumption facilitated operant extinction just as anxiolytics that act as positive modulators of the GABA receptor complex A receptors do, possibly reducing the anxiety or aversion related to non-reinforcement. This effect was increased by intrahippocampal nicotine.

  3. Structural characterization of recombinant crustacyanin subunits from the lobster Homarus americanus

    International Nuclear Information System (INIS)

    Ferrari, Michele; Folli, Claudia; Pincolini, Elisa; McClintock, Timothy S.; Rössle, Manfred; Berni, Rodolfo; Cianci, Michele

    2012-01-01

    The two recombinant apo subunits H1 and H2 from H. americanus have been structurally characterized. Reconstitution studies with astaxanthin reproduced the bathochromic shift of 85–95 nm typical of the natural crustacyanin subunits. Crustacean crustacyanin proteins are linked to the production and modification of carapace colour, with direct implications for fitness and survival. Here, the structural and functional properties of the two recombinant crustacyanin subunits H 1 and H 2 from the American lobster Homarus americanus are reported. The two subunits are structurally highly similar to the corresponding natural apo crustacyanin CRTC and CRTA subunits from the European lobster H. gammarus. Reconstitution studies of the recombinant crustacyanin proteins H 1 and H 2 with astaxanthin reproduced the bathochromic shift of 85–95 nm typical of the natural crustacyanin subunits from H. gammarus in complex with astaxanthin. Moreover, correlations between the presence of crustacyanin genes in crustacean species and the resulting carapace colours with the spectral properties of the subunits in complex with astaxanthin confirmed this genotype–phenotype linkage

  4. Aspartic cathepsin D endopeptidase contributes to extracellular digestion in clawed lobsters Homarus americanus and Homarus gammarus.

    Science.gov (United States)

    Rojo, Liliana; Muhlia-Almazan, Adriana; Saborowski, Reinhard; García-Carreño, Fernando

    2010-11-01

    Acid digestive proteinases were studied in the gastric fluids of two species of clawed lobster (Homarus americanus and Homarus gammarus). An active protein was identified in both species as aspartic proteinase by specific inhibition with pepstatin A. It was confirmed as cathepsin D by mass mapping, N-terminal, and full-length cDNA sequencing. Both lobster species transcribed two cathepsin D mRNAs: cathepsin D1 and cathepsin D2. Cathepsin D1 mRNA was detected only in the midgut gland, suggesting its function as a digestive enzyme. Cathepsin D2 mRNA was found in the midgut gland, gonads, and muscle. The deduced amino acid sequence of cathepsin D1 and cathepsin D2 possesses two catalytic DTG active-site motifs, the hallmark of aspartic proteinases. The putatively active cathepsin D1 has a molecular mass of 36.4 kDa and a calculated pI of 4.14 and possesses three potential glycosylation sites. The sequences showed highest similarities with cathepsin D from insects but also with another crustacean cathepsin D. Cathepsin D1 transcripts were quantified during a starvation period using real-time qPCR. In H. americanus, 15 days of starvation did not cause significant changes, but subsequent feeding caused a 2.5-fold increase. In H. gammarus, starvation caused a 40% reduction in cathepsin D1 mRNA, and no effect was observed with subsequent feeding.

  5. Seasonal and daily plasma corticosterone rhythms in American toads, Bufo americanus

    International Nuclear Information System (INIS)

    Pancak, M.K.; Taylor, D.H.

    1983-01-01

    Concentrations of corticosterone were measured in the plasma of American toads, Bufo americanus, on a seasonal basis using a radioimmunoassay technique. Two populations of toads, maintained under different light conditions, were monitored to observe the effects of photoperiod on the seasonal rhythm of plasma corticosterone. Under a natural photoperiod toads demonstrated a rhythm consisting of a spring peak and a fall peak in corticosterone concentration. Toads maintained under a 12L:12D photoperiod all year round demonstrated a similar rhythm with peaks in the spring and fall. This suggests that an endogenous (circannual) rhythm of corticosterone may be playing an important role in the seasonal change of overt behavior and physiology of Bufo americanus. A daily rhythm of corticosterone was also detected in toads when blood samples were taken every 4 hr. When compared to a previously published circadian rhythm study of locomotor activity, the surge in corticosterone concentration for the day occurred at 1730 just prior to the peak in locomotor activity

  6. Signal enhancement of neutral He emission lines by fast electron bombardment of laser-induced He plasma

    Directory of Open Access Journals (Sweden)

    Hery Suyanto

    2016-08-01

    Full Text Available A time-resolved spectroscopic study is performed on the enhancement signals of He gas plasma emission using nanosecond (ns and picosecond (ps lasers in an orthogonal configuration. The ns laser is used for the He gas plasma generation and the ps laser is employed for the ejection of fast electrons from a metal target, which serves to excite subsequently the He atoms in the plasma. The study is focused on the most dominant He I 587.6 nm and He I 667.8 nm emission lines suggested to be responsible for the He-assisted excitation (HAE mechanism. The time-dependent intensity enhancements induced by the fast electrons generated with a series of delayed ps laser ablations are deduced from the intensity time profiles of both He emission lines. The results clearly lead to the conclusion that the metastable excited triplet He atoms are actually the species overwhelmingly produced during the recombination process in the ns laser-induced He gas plasma. These metastable He atoms are believed to serve as the major energy source for the delayed excitation of analyte atoms in ns laser-induced breakdown spectroscopy (LIBS using He ambient gas.

  7. Signal enhancement of neutral He emission lines by fast electron bombardment of laser-induced He plasma

    Energy Technology Data Exchange (ETDEWEB)

    Suyanto, Hery [Department of Physics, Faculty of Mathematics and Natural Sciences, Udayana University, Kampus Bukit Jimbaran, Denpasar 80361, Bali (Indonesia); Pardede, Marincan [Department of Electrical Engineering, University of Pelita Harapan, 1100 M.H. Thamrin Boulevard, Lippo Village, Tangerang 15811 (Indonesia); Hedwig, Rinda [Department of Computer Engineering, Bina Nusantara University, 9 K.H. Syahdan, Jakarta 14810 (Indonesia); Marpaung, Alion Mangasi [Department of Physics, Faculty of Mathematics and Natural Sciences, Jakarta State University, Rawamangun, Jakarta 12440 (Indonesia); Ramli, Muliadi [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh 23111, NAD (Indonesia); Lie, Tjung Jie; Kurniawan, Koo Hendrik, E-mail: kurnia18@cbn.net.id [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia); Abdulmadjid, Syahrun Nur [Department of Physics, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh 23111, NAD (Indonesia); Tjia, May On [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia); Physics of Magnetism and Photonics Group, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, 10 Ganesha,Bandung 40132 (Indonesia); Kagawa, Kiichiro [Research Center of Maju Makmur Mandiri Foundation, 40 Srengseng Raya, Kembangan, Jakarta Barat 11630 (Indonesia); Fukui Science Education Academy, Takagi Chuo 2 chome, Fukui 910-0804 (Japan)

    2016-08-15

    A time-resolved spectroscopic study is performed on the enhancement signals of He gas plasma emission using nanosecond (ns) and picosecond (ps) lasers in an orthogonal configuration. The ns laser is used for the He gas plasma generation and the ps laser is employed for the ejection of fast electrons from a metal target, which serves to excite subsequently the He atoms in the plasma. The study is focused on the most dominant He I 587.6 nm and He I 667.8 nm emission lines suggested to be responsible for the He-assisted excitation (HAE) mechanism. The time-dependent intensity enhancements induced by the fast electrons generated with a series of delayed ps laser ablations are deduced from the intensity time profiles of both He emission lines. The results clearly lead to the conclusion that the metastable excited triplet He atoms are actually the species overwhelmingly produced during the recombination process in the ns laser-induced He gas plasma. These metastable He atoms are believed to serve as the major energy source for the delayed excitation of analyte atoms in ns laser-induced breakdown spectroscopy (LIBS) using He ambient gas.

  8. Wound healing during hibernation by black bears (Ursus americanus) in the wild: elicitation of reduced scar formation.

    Science.gov (United States)

    Iaizzo, Paul A; Laske, Timothy G; Harlow, Henry J; McClay, Carolyn B; Garshelis, David L

    2012-03-01

    Even mildly hypothermic body or limb temperatures can retard healing processes in mammals. Despite this, we observed that hibernating American black bears (Ursus americanus Pallas, 1780) elicit profound abilities in mounting inflammatory responses to infection and/or foreign bodies. In addition, they resolve injuries during hibernation while maintaining mildly hypothermic states (30-35 °C) and without eating, drinking, urinating or defecating. We describe experimental studies on free-ranging bears that document their abilities to completely resolve cutaneous cuts and punctures incurred during or prior to hibernation. We induced small, full-thickness cutaneous wounds (biopsies or incisions) during early denning, and re-biopsied sites 2-3 months later (near the end of denning). Routine histological methods were used to characterize these skin samples. All biopsied sites with respect to secondary intention (open circular biopsies) and primary intention (sutured sites) healed, with evidence of initial eschar (scab) formation, completeness of healed epidermis and dermal layers, dyskeratosis (inclusion cysts), and abilities to produce hair follicles. These healing abilities of hibernating black bears are a clear survival advantage to animals injured before or during denning. Bears are known to have elevated levels of hibernation induction trigger (delta-opioid receptor agonist) and ursodeoxycholic acid (major bile acid within plasma, mostly conjugated with taurine) during hibernation, which may relate to these wound-healing abilities. Further research as to the underlying mechanisms of wound healing during hibernation could have applications in human medicine. Unique approaches may be found to improve healing for malnourished, hypothermic, diabetic and elderly patients or to reduce scarring associated with burns and traumatic injuries. © 2012 ISZS, Blackwell Publishing and IOZ/CAS.

  9. Determining causes of genetic isolation in a large carnivore (Ursus americanus population to direct contemporary conservation measures.

    Directory of Open Access Journals (Sweden)

    Agnès Pelletier

    Full Text Available The processes leading to genetic isolation influence a population's local extinction risk, and should thus be identified before conservation actions are implemented. Natural or human-induced circumstances can result in historical or contemporary barriers to gene flow and/or demographic bottlenecks. Distinguishing between these hypotheses can be achieved by comparing genetic diversity and differentiation in isolated vs. continuous neighboring populations. In Ontario, American black bears (Ursus americanus are continuously distributed, genetically diverse, and exhibit an isolation-by-distance structuring pattern, except on the Bruce Peninsula (BP. To identify the processes that led to the genetic isolation of BP black bears, we modelled various levels of historical and contemporary migration and population size reductions using forward simulations. We compared simulation results with empirical genetic indices from Ontario black bear populations under different levels of geographic isolation, and conducted additional simulations to determine if translocations could help achieve genetic restoration. From a genetic standpoint, conservation concerns for BP black bears are warranted because our results show that: i a recent demographic bottleneck associated with recently reduced migration best explains the low genetic diversity on the BP; and ii under sustained isolation, BP black bears could lose between 70% and 80% of their rare alleles within 100 years. Although restoring migration corridors would be the most effective method to enhance long-term genetic diversity and prevent inbreeding, it is unrealistic to expect connectivity to be re-established. Current levels of genetic diversity could be maintained by successfully translocating 10 bears onto the peninsula every 5 years. Such regular translocations may be more practical than landscape restoration, because areas connecting the peninsula to nearby mainland black bear populations have been

  10. A goat poxvirus-vectored peste-des-petits-ruminants vaccine induces long-lasting neutralization antibody to high levels in goats and sheep.

    Science.gov (United States)

    Chen, Weiye; Hu, Sen; Qu, Linmao; Hu, Qianqian; Zhang, Qian; Zhi, Haibing; Huang, Kehe; Bu, Zhigao

    2010-07-05

    Recombinant capripoxvirus (CPV) is a promising candidate differentiating infected from vaccinated animals (DIVA) vaccine against peste-des-petits-ruminants (PPR). In order for recombinant CPV to be successfully used in the field, there should exist dependable indicators for quality control of vaccine products, surveillance and vaccination evaluation. Viral neutralization antibody (VNA) is correlated to protection against PPR and is a technically feasible indicator for this purpose. The immunogenicity of this vectored vaccine in goats and sheep, however, has not been fully evaluated. In this study, we generated two recombinant CPV viruses, rCPV-PPRVH and rCPV-PPRVF, that express PPR virus (PPRV) glycoproteins H and F, respectively. Vaccination studies with different dosages of recombinant viruses showed that rCPV-PPRVH was a more potent inducer of PPRV VNA than rCPV-PPRVF. One dose of rCPV-PPRVH was enough to seroconvert 80% of immunized sheep. A second dose induced significantly higher PPRV VNA titers. There was no significant difference in PPRV VNA responses between goats and sheep. Subcutaneous inoculation also induced a significant PPRV VNA response. PPRV VNA could be detected for over 6 months in more than 80% of vaccinated goats and sheep. Boost vaccination at 6-month intervals induced significant re-boost efficacy of PPRV VNA in goats and sheep. More over, two doses of rCPV-PPRVH could completely overcome the interference caused by pre-existing immunity to the CPV vaccine backbone in animals. Vaccination with rCPV-PPRVH also protected goats from virulent CPV challenge. Our results demonstrate that VNA can serve as a dependent indicator for effective vaccination and immune protection of animals in the field. The recombinant CPV vaccine used in our studies could be a practical and useful candidate DIVA vaccine in countries where PPR newly emerges or where stamp-out plans are yet to be implemented. Copyright 2010 Elsevier Ltd. All rights reserved.

  11. Arterial supply and venous drainage of the brain of the black bear (Ursus americanus). I.Gross anatomical distribution

    NARCIS (Netherlands)

    Anderson, W.D.; Anderson, B.G.; Seguin, R.J.

    1989-01-01

    A morphological study of the intracranial vessels of the Black bear (Ursus americanus) was undertaken. The object was to provide basic information related to the vascular pattern in these animals as compared with other carnivores and with the human. Vascular casts were prepared from 6 animals. The

  12. Arterial supply and venous drainage of the brain of the black bear (Ursus americanus). II.Intracranial microvasculature

    NARCIS (Netherlands)

    Anderson, B.G.; Anderson, W.D.; Seguin, R.J.

    1989-01-01

    A morphological study of the intracranial microvasculature of the Black bear (Ursus americanus) using vascular casts was undertaken. The object was to provide basic information regarding structural modifications of the microvasculature that might provide insight into the ability to cope with low

  13. Trichinella Surveillance in Black Bears ( Ursus americanus ) from the Dehcho Region, Northwest Territories, Canada, 2002-15.

    Science.gov (United States)

    Larter, Nicholas C; Elkin, Brett T; Forbes, Lorry B; Wagner, Brent; Allaire, Danny G

    2017-04-01

    We used muscle digestion to test black bears ( Ursus americanus ) from the southwestern Northwest Territories, Canada, for Trichinella. Results showed a prevalence of 4.1%. Some bears had infection intensities of more than one larva per gram of muscle tissue; this level in meat is considered to pose a human consumption safety risk.

  14. Isolation and characterization of new genetic types of toxoplasma gondii and prevalence of trichinella murrelli from black bear (Ursus americanus)

    Science.gov (United States)

    Black bears (Ursus americanus) are hosts for two important zoonotic parasites, Toxoplasma gondii and Trichinella spp. and bears are hunted for human consumption in the USA. Little is known of the genetic diversity of T. gondii circulating in wildlife. In the present study, antibodies to T. gondii we...

  15. Biomarker analysis of American toad (Anaxyrus americanus) and grey tree frog (Hyla versicolor) tadpoles following exposure to atrazine.

    Science.gov (United States)

    The objective of the current study was to use a biomarker-based approach to investigate the influence of atrazine exposure on American toad (Anaxyrus americanus) and grey tree frog (Hyla versicolor) tadpoles. Atrazine is one of the most frequently detected herbicides in environme...

  16. Fragmentation study of isolated and nano-solvated biomolecules induced by collision with multiply charged ions and neutral particles

    International Nuclear Information System (INIS)

    Bernigaud, V.

    2009-01-01

    This thesis concerns a gas phase study of the fragmentation of bio-molecular systems induced by slow collisions with multiply charged ions (in the keV-region), alkali atoms and rare gases. The main objective was to study the physical processes involved in the dissociation of highly electronically excited systems. In order to elucidate the intrinsic properties of certain biomolecules (porphyrins and amino acids) we have performed experiments in the gas phase with isolated systems. The obtained results demonstrate the high stability of porphyrins after electron removal and attachment. Furthermore, a dependence of the fragmentation pattern produced by multiply charged ions on the isomeric structure of the alanine molecule has been shown. In a second part of the thesis, a strong influence of the environment of the biomolecule on the fragmentation channels, their modification and their new opening, has been clearly proven. This phenomenon occurs in the presence of other surrounding biomolecules (clusters of nucleobases) as well as for molecules of a solvent (molecules of water, methanol and acetonitrile) in which the biomolecule is embedded. In order to extend these studies to larger systems, a new experimental set-up, based on an electro-spray ion source combined with a quadrupole mass filter has been developed. Due to the successful tests and proposed improvements of the device future experiments will become available concerning the fragmentation of large charged and solvated bio-molecular systems induced by collision processes. (author) [fr

  17. Receptor-binding domain of SARS-CoV spike protein induces highly potent neutralizing antibodies: implication for developing subunit vaccine

    International Nuclear Information System (INIS)

    He Yuxian; Zhou Yusen; Liu Shuwen; Kou Zhihua; Li Wenhui; Farzan, Michael; Jiang Shibo

    2004-01-01

    The spike (S) protein of severe acute respiratory syndrome (SARS) coronavirus (CoV), a type I transmembrane envelope glycoprotein, consists of S1 and S2 domains responsible for virus binding and fusion, respectively. The S1 contains a receptor-binding domain (RBD) that can specifically bind to angiotensin-converting enzyme 2 (ACE2), the receptor on target cells. Here we show that a recombinant fusion protein (designated RBD-Fc) containing 193-amino acid RBD (residues 318-510) and a human IgG1 Fc fragment can induce highly potent antibody responses in the immunized rabbits. The antibodies recognized RBD on S1 domain and completely inhibited SARS-CoV infection at a serum dilution of 1:10,240. Rabbit antisera effectively blocked binding of S1, which contains RBD, to ACE2. This suggests that RBD can induce highly potent neutralizing antibody responses and has potential to be developed as an effective and safe subunit vaccine for prevention of SARS

  18. A cross-reacting material CRM197 conjugate vaccine induces diphtheria toxin neutralizing antibody response in children and adolescents infected or not with HIV.

    Science.gov (United States)

    Silva, Giselle P; Santos, Rafaela S; Pereira-Manfro, Wânia F; Ferreira, Bianca; Barreto, Daniella M; Frota, Ana Cristina C; Hofer, Cristina B; Milagres, Lucimar G

    2017-07-05

    Anti-diphtheria antibody levels decrease with aging, and frequent booster vaccinations are required to maintain herd immunity. We analyzed the diphtheria toxin neutralizing antibody (DT-Nab) response induced by a conjugate vaccine (meningococcal C polysaccharide-CRM 197 ) in HIV-vertically infected (HI) children and adolescents and healthy controls (HC) with matched age. We report the association of DT-Nab with the bactericidal antibodies to serogroup C meningococcus (MenC). Before vaccination, 21 HI patients (50%) had no protection against diphtheria (≤0.01IU/ml of antibody) and only 8 (19%) showed complete protection (≥0.1IU/ml). About half of the HC (56%) had complete protection before immunization and 6 subjects (12%) had no protection against diphtheria. After one and two vaccine injections, 96% of HC and 64% of HI vaccinees, respectively, showed full protection against diphtheria. These data indicate that CRM 197 was able to induce primary and/or booster response in both groups of individuals. Copyright © 2017 Elsevier Ltd. All rights reserved.

  19. Pichia pastoris-Expressed Bivalent Virus-Like Particulate Vaccine Induces Domain III-Focused Bivalent Neutralizing Antibodies without Antibody-Dependent Enhancement in Vivo

    Directory of Open Access Journals (Sweden)

    Rahul Shukla

    2018-01-01

    Full Text Available Dengue, a significant public health problem in several countries around the world, is caused by four different serotypes of mosquito-borne dengue viruses (DENV-1, -2, -3, and -4. Antibodies to any one DENV serotype which can protect against homotypic re-infection, do not offer heterotypic cross-protection. In fact, cross-reactive antibodies may augment heterotypic DENV infection through antibody-dependent enhancement (ADE. A recently launched live attenuated vaccine (LAV for dengue, which consists of a mixture of four chimeric yellow-fever/dengue vaccine viruses, may be linked to the induction of disease-enhancing antibodies. This is likely related to viral interference among the replicating viral strains, resulting in an unbalanced immune response, as well as to the fact that the LAV encodes prM, a DENV protein documented to elicit ADE-mediating antibodies. This makes it imperative to explore the feasibility of alternate ADE risk-free vaccine candidates. Our quest for a non-replicating vaccine centered on the DENV envelope (E protein which mediates virus entry into the host cell and serves as an important target of the immune response. Serotype-specific neutralizing epitopes and the host receptor recognition function map to E domain III (EDIII. Recently, we found that Pichia pastoris-expressed DENV E protein, of all four serotypes, self-assembled into virus-like particles (VLPs in the absence of prM. Significantly, these VLPs displayed EDIII and elicited EDIII-focused DENV-neutralizing antibodies in mice. We now report the creation and characterization of a novel non-replicating recombinant particulate vaccine candidate, produced by co-expressing the E proteins of DENV-1 and DENV-2 in P. pastoris. The two E proteins co-assembled into bivalent mosaic VLPs (mVLPs designated as mE1E2bv VLPs. The mVLP, which preserved the serotype-specific antigenic integrity of its two component proteins, elicited predominantly EDIII-focused homotypic virus-neutralizing

  20. Amines are likely to enhance neutral and ion-induced sulfuric acid-water nucleation in the atmosphere more effectively than ammonia

    Directory of Open Access Journals (Sweden)

    T. Kurtén

    2008-07-01

    Full Text Available We have studied the structure and formation thermodynamics of dimer clusters containing H2SO4 or HSO4 together with ammonia and seven different amines possibly present in the atmosphere, using the high-level ab initio methods RI-MP2 and RI-CC2. As expected from e.g. proton affinity data, the binding of all studied amine-H2SO4 complexes is significantly stronger than that of NH3•H2SO4, while most amine-HSO4 complexes are only somewhat more strongly bound than NH3•HSO4. Further calculations on larger cluster structures containing dimethylamine or ammonia together with two H2SO4 molecules or one H2SO4 molecule and one HSO4 ion demonstrate that amines, unlike ammonia, significantly assist the growth of not only neutral but also ionic clusters along the H2SO4 co-ordinate. A sensitivity analysis indicates that the difference in complexation free energies for amine- and ammonia-containing clusters is large enough to overcome the mass-balance effect caused by the fact that the concentration of amines in the atmosphere is probably 2 or 3 orders of magnitude lower than that of ammonia. This implies that amines might be more important than ammonia in enhancing neutral and especially ion-induced sulfuric acid-water nucleation in the atmosphere.

  1. International Network for Comparison of HIV Neutralization Assays: The NeutNet Report II

    NARCIS (Netherlands)

    Heyndrickx, Leo; Heath, Alan; Sheik-Khalil, Enas; Alcami, Jose; Bongertz, Vera; Jansson, Marianne; Malnati, Mauro; Montefiori, David; Moog, Christiane; Morris, Lynn; Osmanov, Saladin; Polonis, Victoria; Ramaswamy, Meghna; Sattentau, Quentin; Tolazzi, Monica; Schuitemaker, Hanneke; Willems, Betty; Wrin, Terri; Fenyö, Eva Maria; Scarlatti, Gabriella

    2012-01-01

    Background: Neutralizing antibodies provide markers for vaccine-induced protective immunity in many viral infections. By analogy, HIV-1 neutralizing antibodies induced by immunization may well predict vaccine effectiveness. Assessment of neutralizing antibodies is therefore of primary importance,

  2. Neutralization of TSLP inhibits airway remodeling in a murine model of allergic asthma induced by chronic exposure to house dust mite.

    Directory of Open Access Journals (Sweden)

    Zhuang-Gui Chen

    Full Text Available Chronic allergic asthma is characterized by Th2-typed inflammation, and contributes to airway remodeling and the deterioration of lung function. However, the initiating factor that links airway inflammation to remodeling is unknown. Thymic stromal lymphopoietin (TSLP, an epithelium-derived cytokine, can strongly activate lung dendritic cells (DCs through the TSLP-TSLPR and OX40L-OX40 signaling pathways to promote Th2 differentiation. To determine whether TSLP is the underlying trigger of airway remodeling in chronic allergen-induced asthma, we induced allergic airway inflammation in mice by intranasal administration of house dust mite (HDM extracts for up to 5 consecutive weeks. We showed that repeated respiratory exposure to HDM caused significant airway eosinophilic inflammation, peribronchial collagen deposition, goblet cell hyperplasia, and airway hyperreactivity (AHR to methacholine. These effects were accompanied with a salient Th2 response that was characterized by the upregulation of Th2-typed cytokines, such as IL-4 and IL-13, as well as the transcription factor GATA-3. Moreover, the levels of TSLP and transforming growth factor beta 1 (TGF-β1 were also increased in the airway. We further demonstrated, using the chronic HDM-induced asthma model, that the inhibition of Th2 responses via neutralization of TSLP with an anti-TSLP mAb reversed airway inflammation, prevented structural alterations, and decreased AHR to methacholine and TGF-β1 level. These results suggest that TSLP plays a pivotal role in the initiation and persistence of airway inflammation and remodeling in the context of chronic allergic asthma.

  3. A vaccine of L2 epitope repeats fused with a modified IgG1 Fc induced cross-neutralizing antibodies and protective immunity against divergent human papillomavirus types.

    Science.gov (United States)

    Chen, Xue; Liu, Hongyang; Zhang, Ting; Liu, Yanchun; Xie, Xixiu; Wang, Zhirong; Xu, Xuemei

    2014-01-01

    Current human papillomavirus (HPV) major capsid protein L1 virus-like particles (VLPs)-based vaccines in clinic induce strong HPV type-specific neutralizing antibody responses. To develop pan-HPV vaccines, here, we show that the fusion protein E3R4 consisting of three repeats of HPV16 L2 aa 17-36 epitope (E3) and a modified human IgG1 Fc scaffold (R4) induces cross-neutralizing antibodies and protective immunity against divergent HPV types. E3R4 was expressed as a secreted protein in baculovirus expression system and could be simply purified by one step Protein A affinity chromatography with the purity above 90%. Vaccination of E3R4 formulated with Freunds adjuvant not only induced cross-neutralizing antibodies against HPV pseudovirus types 16, 18, 45, 52, 58, 6, 11 and 5 in mice, but also protected mice against vaginal challenges with HPV pseudovirus types 16, 45, 52, 58, 11 and 5 for at least eleven months after the first immunization. Moreover, vaccination of E3R4 formulated with FDA approved adjuvant alum plus monophosphoryl lipid A also induced cross-neutralizing antibodies against HPV types 16, 18 and 6 in rabbits. Thus, our results demonstrate that delivery of L2 antigen as a modified Fc-fusion protein may facilitate pan-HPV vaccine development.

  4. Temperature increase can cause hyperecdysonism in American lobsters (Homarus americanus) injected with ecdysterone

    Energy Technology Data Exchange (ETDEWEB)

    Aiken, D E; Waddy, S L

    1975-10-01

    In the lobster Homarus americanus the threshold dose for premolt acceleration by ecdysterone can be altered by changes in temperature. Two dose levels of ecdysterone (0.5 and 1.0 ..mu..g/g body weight) were compared at three different temperatures (10, 17, 21/sup 0/C); all three doses remained subthreshold at 10/sup 0/C but at 17/sup 0/C the 1.0-..mu..g dose caused hyperecdysonism--rapid but abnormal completion of premolt terminating in death at ecdysis. In contrast, the 0.5-..mu..g dose remained subthreshold even at 21/sup 0/C. These results demonstrate a dose-temperature relation for response to injected ecdysterone.

  5. Population viability and connectivity of the Louisiana black bear (Ursus americanus luteolus)

    Science.gov (United States)

    Laufenberg, Jared S.; Clark, Joseph D.

    2014-01-01

    In 1992, the U.S. Fish and Wildlife Service (USFWS) granted Ursus americanus luteolus (Louisiana black bear) threatened status under the U.S. Endangered Species Act of 1973, listing loss and fragmentation of habitat as the primary threats. A study was developed by the U.S. Geological Survey in cooperation with the University of Tennessee, the Louisiana Department of Wildlife and Fisheries, and the USFWS to estimate demographic rates and genetic structure of Louisiana black bear populations; evaluate relations between environmental and anthropogenic factors and demographic, genetic, and movement characteristics of Louisiana black bear populations; and develop data-driven stochastic population projection models to assess long-term persistence of individual subpopulations and the overall black bear population in Louisiana.

  6. Structure of a two-CAP-domain protein from the human hookworm parasite Necator americanus

    Energy Technology Data Exchange (ETDEWEB)

    Asojo, Oluwatoyin A., E-mail: oasojo@unmc.edu [Pathology and Microbiology Department, 986495 Nebraska Medical Center, Omaha, NE 68198-6495 (United States)

    2011-05-01

    The first structure of a two-CAP-domain protein, Na-ASP-1, from the major human hookworm parasite N. americanus refined to a resolution limit of 2.2 Å is presented. Major proteins secreted by the infective larval stage hookworms upon host entry include Ancylostoma secreted proteins (ASPs), which are characterized by one or two CAP (cysteine-rich secretory protein/antigen 5/pathogenesis related-1) domains. The CAP domain has been reported in diverse phylogenetically unrelated proteins, but has no confirmed function. The first structure of a two-CAP-domain protein, Na-ASP-1, from the major human hookworm parasite Necator americanus was refined to a resolution limit of 2.2 Å. The structure was solved by molecular replacement (MR) using Na-ASP-2, a one-CAP-domain ASP, as the search model. The correct MR solution could only be obtained by truncating the polyalanine model of Na-ASP-2 and removing several loops. The structure reveals two CAP domains linked by an extended loop. Overall, the carboxyl-terminal CAP domain is more similar to Na-ASP-2 than to the amino-terminal CAP domain. A large central cavity extends from the amino-terminal CAP domain to the carboxyl-terminal CAP domain, encompassing the putative CAP-binding cavity. The putative CAP-binding cavity is a characteristic cavity in the carboxyl-terminal CAP domain that contains a His and Glu pair. These residues are conserved in all single-CAP-domain proteins, but are absent in the amino-terminal CAP domain. The conserved His residues are oriented such that they appear to be capable of directly coordinating a zinc ion as observed for CAP proteins from reptile venoms. This first structure of a two-CAP-domain ASP can serve as a template for homology modeling of other two-CAP-domain proteins.

  7. Implications of Future Northwest Atlantic Bottom Temperatures on the American Lobster (Homarus americanus) Fishery

    Science.gov (United States)

    Rheuban, Jennie E.; Kavanaugh, Maria T.; Doney, Scott C.

    2017-12-01

    Sea surface temperatures of the northwest Atlantic have warmed dramatically over the last several decades, while benthic temperatures have increased at a slower pace. Here we analyze a subset of the CMIP5 global Earth system model ensemble using a statistical downscaling approach to determine potential future changes in benthic temperatures on the northwest Atlantic continental shelf and slope (business-as-usual (RCP8.5) and a climate-policy (RCP4.5) scenario are projected to increase by 0-1.5°C and 1.2-2.4°C by 2050 and 0-1.9°C and 2.3-4.3°C by the end of the century for RCP4.5 and RCP8.5, respectively. H. americanus experiences thermal stress at temperatures above 20°C, and projected increases in temperature is likely to result in changes in the distribution of optimal thermal egg hatching and settlement indicators. Inshore regions of southern New England, where H. americanus biomass and catch have been declining historically, will likely become inhospitable under either future scenario, while thermal egg hatching and settlement indicators will expand offshore and in the Gulf of Maine. These changes imply that members of the fishery based in southern New England may need to recapitalize to larger vessels to prepare for potential changes brought on by future climate warming. Results from the downscaling presented here can be useful in preparing for potential changes to other fisheries or in future climate vulnerability analyses.

  8. Hookworm infections among migrant workers in Malaysia: Molecular identification of Necator americanus and Ancylostoma duodenale.

    Science.gov (United States)

    Sahimin, Norhidayu; Lim, Yvonne Ai Lian; Douadi, Benacer; Mohd Khalid, Mohd Khairul Nizam; Wilson, John-James; Behnke, Jerzy M; Mohd Zain, Siti Nursheena

    2017-09-01

    Ongoing urbanisation of the working population as well as cross-border migration of workers particularly into large cities has contributed to the development and growth of urban slums. These deprived areas are conducive for the transmission of intestinal pathogens including hookworm. The aim of this study was to determine both the prevalence and species identity of hookworm infections among the migrant worker community in Malaysia. A total of 388 faecal samples were collected from migrant workers between September 2014 and August 2015, representing workers from five employment sectors: construction, manufacturing, agriculture and plantations, food services and domestic services. Faecal samples were examined by microscopy and positive samples were subjected to molecular analysis. A total of 51 samples (13.1%) were positive by microscopy for hookworm infections. A two-step PCR based method amplifying a fragment of the 28S rRNA-ITS2 region was used to identify infections by Necator americanus and Ancylostoma spp. PCR products positive for Ancylostoma spp. were sequenced bidirectionally, and sequences analysed through BLAST and phylogenetic analysis. Samples containing Ancylostoma duodenale were further characterized by amplification and sequencing a fragment of cytochrome c oxidase subunit 1 (cox1) gene. PCR amplicons were successfully obtained from 42 (82.4%) of 51 samples, with 81.0% (34 of 42) identified as Necator americanus, 16.7% (7 of 42) as Ancylostoma spp. and 2.4% (1 of 42) as mixed infections of both species. All eight Ancylostoma spp. were confirmed to be Ancylostoma duodenale and this is the first time A. duodenale was reported in Malaysia. Samples containing A. duodenale from Nepalese and Indonesian workers shared high-similarity and were distinct compared to sequences from other countries. This study highlights the prevalence of hookworm infections among migrant workers living in Malaysia. Our findings underscore the necessity of screening migrant

  9. Structure of a two-CAP-domain protein from the human hookworm parasite Necator americanus

    International Nuclear Information System (INIS)

    Asojo, Oluwatoyin A.

    2011-01-01

    The first structure of a two-CAP-domain protein, Na-ASP-1, from the major human hookworm parasite N. americanus refined to a resolution limit of 2.2 Å is presented. Major proteins secreted by the infective larval stage hookworms upon host entry include Ancylostoma secreted proteins (ASPs), which are characterized by one or two CAP (cysteine-rich secretory protein/antigen 5/pathogenesis related-1) domains. The CAP domain has been reported in diverse phylogenetically unrelated proteins, but has no confirmed function. The first structure of a two-CAP-domain protein, Na-ASP-1, from the major human hookworm parasite Necator americanus was refined to a resolution limit of 2.2 Å. The structure was solved by molecular replacement (MR) using Na-ASP-2, a one-CAP-domain ASP, as the search model. The correct MR solution could only be obtained by truncating the polyalanine model of Na-ASP-2 and removing several loops. The structure reveals two CAP domains linked by an extended loop. Overall, the carboxyl-terminal CAP domain is more similar to Na-ASP-2 than to the amino-terminal CAP domain. A large central cavity extends from the amino-terminal CAP domain to the carboxyl-terminal CAP domain, encompassing the putative CAP-binding cavity. The putative CAP-binding cavity is a characteristic cavity in the carboxyl-terminal CAP domain that contains a His and Glu pair. These residues are conserved in all single-CAP-domain proteins, but are absent in the amino-terminal CAP domain. The conserved His residues are oriented such that they appear to be capable of directly coordinating a zinc ion as observed for CAP proteins from reptile venoms. This first structure of a two-CAP-domain ASP can serve as a template for homology modeling of other two-CAP-domain proteins

  10. Immunoglobulin G and F(ab')2 polyvalent antivenoms do not differ in their ability to neutralize hemorrhage, edema and myonecrosis induced by Bothrops asper (terciopelo) snake venom

    OpenAIRE

    León Montero, Guillermo; Rojas Céspedes, Gustavo; Lomonte, Bruno; Gutiérrez, José María

    1997-01-01

    The ability of whole immunoglobulin G (IgG) and F(ab')2 polyvalent (Crotalinae) antivenoms to neutralize the hemorrhagic, edema-forming and myotoxic activities of Bothrops asper venom was studied. Both antivenoms were adjusted to the same neutralizing potency against lethal and hemorrhagic activities in experiments where venom and antivenoms were incubated before injection. Thus, in these experimental conditions, differences in the neutralizing ability in experiments involving independent inj...

  11. Comparative study on the ability of IgG and F(ab')2 antivenoms to neutralize lethal and myotoxic effects induced by Micrurus nigrocinctus (coral snake) venom

    OpenAIRE

    León Montero, Guillermo; Stiles, Bradley G.; Alape Girón, Alberto; Rojas Céspedes, Gustavo; Gutiérrez, José María

    1999-01-01

    A comparative study was performed on the ability of IgG and F(ab')2 antivenoms to neutralize lethal and myotoxic activities of Micrurus nigrocinctus venom. Both antivenoms were adjusted to a similar neutralizing potency in experiments where venom and antivenoms were preincubated prior to injection. No significant differences were observed between IgG and F(ab')2 antivenoms concerning neutralization of lethal effect in rescue experiments, i.e., when antivenom was administered intravenously aft...

  12. Neutralizing antibodies induced by recombinant virus-like particles of enterovirus 71 genotype C4 inhibit infection at pre- and post-attachment steps.

    Directory of Open Access Journals (Sweden)

    Zhiqiang Ku

    Full Text Available BACKGROUND: Enterovirus 71 (EV71 is a major causative agent of hand, foot and mouth disease, which has been prevalent in Asia-Pacific regions, causing significant morbidity and mortality in young children. Antibodies elicited by experimental EV71 vaccines could neutralize infection in vitro and passively protect animal models from lethal challenge, indicating that neutralizing antibodies play an essential role in protection. However, how neutralizing antibodies inhibit infection in vitro remains unclear. METHODS/FINDINGS: In the present study, we explored the mechanisms of neutralization by antibodies against EV71 virus-like particles (VLPs. Recombinant VLPs of EV71 genotype C4 were produced in insect cells using baculovirus vectors. Immunization with the VLPs elicited a high-titer, EV71-specific antibody response in mice. Anti-VLP mouse sera potently neutralized EV71 infection in vitro. The neutralizing antibodies in the anti-VLP mouse sera were found to target mainly an extremely conserved epitope (FGEHKQEKDLEYGAC located at the GH loop of the VP1 protein. The neutralizing anti-VLP antisera were able to inhibit virus binding to target cells efficiently. In addition, post-attachment treatment of virus-bound cells with the anti-VLP antisera also neutralized virus infection, although the antibody concentration required was higher than that of the pre-attachment treatment. CONCLUSIONS: Collectively, our findings represent a valuable addition to the understanding of mechanisms of EV71 neutralization and have strong implications for EV71 vaccine development.

  13. Ultraviolet light induces double-strand breaks in DNA of cultured human P3 cells as measured by neutral filter elution

    International Nuclear Information System (INIS)

    Peak, J.G.; Peak, M.J.

    1990-01-01

    Neutral filter elution at pH 7.2 and 9.6 was used to measure the induction of DNA lesions in human P3 teratocarcinoma cells by monochromatic 254-, 270-, 313-, 334-, 334-,365-, and 405-nm radiation and by 60 gamma rays. In this assay DNA double-strand breaks (dsb) increase the rate of elution of DNA from cell lysates on a filter. Yields of dsb as measured by this procedure were determined by using a calibration of the assay that correlates elution parameters with number of dsb caused by disintegration of 125 I incorporated into the DNA. Analysis of fluence responses obtained by using the calibrated assay indicated that the number of dsb induced per dalton of DNA as measured by this assay is proportional to the square of the fluence at all the energies of radiation studied, implying that the induction of these lesions may be a two-hit event. Analysis of the relative efficiencies for the induction of dsb by ultraviolet radiation, corrected for quantum efficiency, revealed a spectrum that coincided closely with that for the induction of single-strand breaks (ssb) in the same cells, having a close fit with the spectrum of nucleic acid in the UVC and UVB region below 313 nm, and a shoulder in the UVA region. It was calculated, however, that there may be too few ssb for dsb to result from randomly distributed closely opposed ssb. (author)

  14. Intravenous administration of bone marrow-derived multipotent mesenchymal stromal cells has a neutral effect on obesity-induced diabetic cardiomyopathy

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    Sebastián D Calligaris

    2013-01-01

    Full Text Available Obesity is a major global health issue. Obese patients develop metabolic syndrome, which is a cluster of clinical features characterized by insulin resistance and dyslipidemia. Its cardiac manifestation, diabetic cardiomyopathy, leads to heart failure. Bone marrow-derived multipotent mesenchymal stromal cells, also referred to as mesenchymal stem cells (MSC are envisioned as a therapeutic tool not only for cardiovascular diseases but also for other degenerative conditions. Our aim was to evaluate whether the intravenous administration of MSC modifies cardiac dysfunction in obese mice. To this end, C57BL/6 mice were fed a regular (normal or high-fat diet (obese. Obese animals received the vehicle (obese, a single dose (obese + 1x MSC or three doses (obese + 3x MSC of 0.5x10(6 syngeneic MSC. Two to three months following MSC administration, cardiac function was assessed by cardiac catheterization, at basal condition and after a pharmacological stress. Compared to normal mice, obese mice presented hyperglycemia, hyperinsulinemia, hypercholesterolemia and cardiac dysfunction after stress condition. Exogenous MSC neither improved nor impaired this cardiac dysfunction. Thus, intravenous administration of MSC has neutral effect on obesity-induced diabetic cardiomyopathy

  15. Motavizumab, A Neutralizing Anti-Respiratory Syncytial Virus (Rsv Monoclonal Antibody Significantly Modifies The Local And Systemic Cytokine Responses Induced By Rsv In The Mouse Model

    Directory of Open Access Journals (Sweden)

    Jafri Hasan S

    2007-10-01

    Full Text Available Abstract Motavizumab (MEDI-524 is a monoclonal antibody with enhanced neutralizing activity against RSV. In mice, motavizumab suppressed RSV replication which resulted in significant reduction of clinical parameters of disease severity. We evaluated the effect of motavizumab on the local and systemic immune response induced by RSV in the mouse model. Balb/c mice were intranasally inoculated with 106.5 PFU RSV A2 or medium. Motavizumab was given once intraperitoneally (1.25 mg/mouse as prophylaxis, 24 h before virus inoculation. Bronchoalveolar lavage (BAL and serum samples were obtained at days 1, 5 (acute and 28 (long-term post inoculation and analyzed with a multiplex assay (Beadlyte Upstate, NY for simultaneous quantitation of 18 cytokines: IL-1α, IL-1β, IL-2, IL-3, IL-4, IL-5, IL-6, KC (similar to human IL-8, IL-10, IL-12p40, IL-12p70, IL-13, IL-17, TNF-α, MCP-1, RANTES, IFN-γ and GM-CSF. Overall, cytokine concentrations were lower in serum than in BAL samples. By day 28, only KC was detected in BAL specimens at low concentrations in all groups. Administration of motavizumab significantly reduced (p

  16. Investigating the mechanism for maintaining eucalcemia despite immobility and anuria in the hibernating American black bear (Ursus americanus).

    Science.gov (United States)

    Seger, Rita L; Cross, Randal A; Rosen, Clifford J; Causey, Robert C; Gundberg, Caren M; Carpenter, Thomas O; Chen, Tai C; Halteman, William A; Holick, Michael F; Jakubas, Walter J; Keisler, Duane H; Seger, Richard M; Servello, Frederick A

    2011-12-01

    Ursine hibernation uniquely combines prolonged skeletal unloading, anuria, pregnancy, lactation, protein recycling, and lipolysis. This study presents a radiographic and biochemical picture of bone metabolism in free-ranging, female American black bears (Ursus americanus) that were active (spring bears and autumn bears) or hibernating (hibernating bears). Hibernating bears included lactating and non-lactating individuals. We measured serum calcium, albumin, inorganic phosphate, creatinine, bone specific alkaline phosphatase (BSALP), CTX, parathyroid hormone, insulin-like growth factor-I (IGF-l), leptin, 25-hydroxyvitamin D [25(OH)D], 1,25-dihydroxyvitamin D [1,25(OH)(2)D] and sclerostin from 35 to 50 tranquilized hibernating bears and 14 to 35 tranquilized spring bears. We compared metacarpal cortical indices (MCI), measured by digital X-ray radiogrammetry, from 60 hunter-killed autumn bears and 79 tranquilized, hibernating bears. MCI was greater in autumn than winter in younger bears, but showed no seasonal difference in older bears. During hibernation eucalcemia was maintained, BSALP was suppressed, and CTX was in the range expected for anuria. During hibernation 1,25(OH)(2)D was produced despite anuria. 1,25(OH)(2)D and IGF-I were less in hibernating than spring bears. In a quarter of hibernating bears, sclerostin was elevated. Leptin was greater in hibernating than spring bears. In hibernating bears, leptin correlated positively with BSALP in non-lactating bears and with CTX in lactating bears. Taken together the biochemical and radiographic findings indicate that during hibernation, bone turnover was persistent, balanced, and suppressed; bone resorption was lower than expected for an unloaded skeleton; and there was no unloading-induced bone loss. The skeleton appears to perceive that it was loaded when it was actually unloaded during hibernation. However, at the level of sclerostin, the skeleton recognized that it was unloaded. During hibernation leptin

  17. Immunization of pregnant cows with Shiga toxin-2 induces high levels of specific colostral antibodies and lactoferrin able to neutralize E. coli O157:H7 pathogenicity.

    Science.gov (United States)

    Albanese, Adriana; Sacerdoti, Flavia; Seyahian, E Abril; Amaral, Maria Marta; Fiorentino, Gabriela; Fernandez Brando, Romina; Vilte, Daniel A; Mercado, Elsa C; Palermo, Marina S; Cataldi, Angel; Zotta, Elsa; Ibarra, Cristina

    2018-03-20

    E. coli O157:H7 is a foodborne pathogen responsible for bloody diarrhea, hemorrhagic colitis and hemolytic uremic syndrome (HUS). The objective of the present work was to evaluate the ability of colostral IgG obtained from Stx2-immunized cows to prevent against E. coli O157:H7 infection and Stx2 cytotoxicity. Hyperimmune colostrum (HC) was obtained from cows intramuscularly immunized with inactivated Stx2 or vehicle for controls. Colostral IgG was purified by affinity chromatography. Specific IgG antibodies against Stx2 and bovine lactoferrin (bLF) levels in HC and the corresponding IgG (HC-IgG/bLF) were determined by ELISA. The protective effects of HC-IgG/bLF against Stx2 cytotoxicity and adhesion of E. coli O157:H7 and its Stx2-negative mutant were analyzed in HCT-8 cells. HC-IgG/bLF prevention against E. coli O157:H7 was studied in human colon and rat colon loops. Protection against a lethal dose of E. coli O157:H7 was evaluated in a weaned mice model. HC-IgG/bLF showed high anti-Stx2 titers and high bLF levels that were able to neutralize the cytotoxic effects of Stx2 in vitro and in vivo. Furthermore, HC-IgG/bLF avoided the inhibition of water absorption induced by E. coli O157:H7 in human colon and also the pathogenicity of E. coli O157:H7 and E. coli O157:H7Δstx2 in rat colon loops. Finally, HC-IgG/bLF prevented in a 100% the lethality caused by E. coli O157:H7 in a weaned mice model. Our study suggests that HC-IgG/bLF have protective effects against E. coli O157:H7 infection. These beneficial effects may be due to specific anti-Stx2 neutralizing antibodies in combination with high bLF levels. These results allow us to consider HC-IgG/bLF as a nutraceutical tool which could be used in combination with balanced supportive diets to prevent HUS. However further studies are required before recommendations can be made for therapeutic and clinical applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. First report of Taenia arctos (Cestoda: Taeniidae) from grizzly (Ursus arctos horribilis) and black bears (Ursus americanus) in North America.

    Science.gov (United States)

    Catalano, Stefano; Lejeune, Manigandan; Verocai, Guilherme G; Duignan, Pádraig J

    2014-04-01

    The cestode Taenia arctos was found at necropsy in the small intestine of a grizzly (Ursus arctos horribilis) and a black bear (Ursus americanus) from Kananaskis Country in southwestern Alberta, Canada. The autolysis of the tapeworm specimens precluded detailed morphological characterization of the parasites but molecular analysis based on mitochondrial DNA cytochrome c oxidase subunit 1 gene confirmed their identity as T. arctos. This is the first report of T. arctos from definitive hosts in North America. Its detection in Canadian grizzly and black bears further supports the Holarctic distribution of this tapeworm species and its specificity for ursids as final hosts. Previously, T. arctos was unambiguously described at its adult stage in brown bears (Ursus arctos arctos) from Finland, and as larval stages in Eurasian elk (Alces alces) from Finland and moose (Alces americanus) from Alaska, USA. Given the morphological similarity between T. arctos and other Taenia species, the present study underlines the potential for misidentification of tapeworm taxa in previous parasitological reports from bears and moose across North America. The biogeographical history of both definitive and intermediate hosts in the Holarctic suggests an ancient interaction between U. arctos, Alces spp., and T. arctos, and a relatively recent host-switching event in U. americanus. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  19. Population structure and reproduction of Menticirrhus americanus (Linnaeus, 1758 (Teleostei, Sciaenidae in Ubatuba-Enseada Bay, Santa Catarina, Brazil

    Directory of Open Access Journals (Sweden)

    Carolina Ferreira Haluch

    2011-02-01

    Full Text Available Population structure and reproductive aspects of the southern kingfish Menticirrhus americanus in Santa Catarina northern coast were investigated. Trawl nets were used for the monthly surveys between October (2003 and September (2004. A total of 425 individuals between 4.2 and 31.8cm (mean 12.7 ± 5.7 were analyzed, and the majority of the individuals (4.2 to12.5cm was captured mainly in summer, autumn and winter, while larger individuals were captured in spring. Females of all size classes were predominant during summer and winter, and weight/length relationship showed significant differences between sexes and a positive alometric growth for the species. The size at first maturity (L50 was estimated in 16.7cm for females and 15.4cm for males. The reproductive period occurred in warm seasons, and M. americanus showed multiple spawning. The hepatossomatic index demonstrated a similar seasonal pattern as the gonadosomatic index, and was a good indicator of the spawning. The condition factor wasn’t a good indicator of the spawning period, but it was related with the recovery process and gonad maturation. Characteristics of the population dynamic showed that M. americanus utilizes the study area for reproduction and recruitment.

  20. The sensorial structures of Spondylus americanus Hermann,1781 (Mollusca: Bivalvia, Spondylidae

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    Marina Gomes Viana

    2007-09-01

    Full Text Available Adult animals of Spondylus americanus were analyzed and specialized sensorial structures, the sensorial papillae and the eyes, were characterized. The sensorial papillae were projections on the edge of the mantle in form of light brown fingers which had function of percepting stimulus coming from the medium. They were constituted by loose conjunctive tissues with longitudinal muscular fibers and externally covered by ciliated cubic epithelium, which presented high amount of melanocytes that gave the coloration of the papillae. The eyes were more complex, being on small stalks histologically similar to the papillae. They exhibited a circular formate and had a metallic blue color. Theses structures were constituted by a corneo epithelium, cornea, lens, retina, basal stalk, periocular band and optical nerve. The eyes were distributed asymmetrically to both valves related with the sedentarism of the species. Right valve presented a smaller number of eyes when compared to left one.Foram examinados exemplares adultos de Spondylus. americanus Hermann, 1781 e estruturas especializadas na percepção de estímulos foram caracterizadas: as papilas sensoriais e os ocelos. As papilas sensoriais são projeções do bordo manto em forma de dedos de cor castanha e com a função de perceber estímulos vindo do meio, são constituídas por tecido conjuntivo frouxo contendo fibras musculares longitudinais e revestidas externamente por epitélio cúbico ciliado, o qual apresenta grande quantidade de melanócitos, que dão a coloração das papilas. Os ocelos são mais complexos, estando sobre pequenos pedúnculos histologicamente semelhante às papilas, têm formato circular e possui cor azul metálica. Constituí-se por um epitélio córneo, córnea, lente, retina, pedúnculo basal, banda periocular e nervo óptico. Os ocelos distribuem-se assimetricamente por ambas as valvas, o que está relacionado com o sedentarismo da espécie. A valva direita apresenta

  1. Comparison between IgG and F(ab′)2 polyvalent antivenoms: neutralization of systemic effects induced by Bothrops asper venom in mice, extravasation to muscle tissue, and potential for induction of adverse reactions

    OpenAIRE

    León Montero, Guillermo; Monge Monge, María; Rojas Umaña, Ermila; Lomonte, Bruno; Gutiérrez, José María

    2001-01-01

    Whole IgG and F(ab′)2 equine-derived polyvalent (Crotalinae) antivenoms, prepared from the same batch of hyperimmune plasma, were compared in terms of neutralization of the lethal and defibrinating activities induced by Bothrops asper venom, their ability to reach the muscle tissue compartment in envenomated mice, and their potential for the induction of adverse reactions. Both preparations were adjusted to the same potency against the lethal effect of B. asper venom in experiments involving ...

  2. Serosurvey for selected pathogens in free-ranging American black bears (Ursus americanus) in Maryland, USA.

    Science.gov (United States)

    Bronson, Ellen; Spiker, Harry; Driscoll, Cindy P

    2014-10-01

    American black bears (Ursus americanus) in Maryland, USA, live in forested areas in close proximity to humans and their domestic pets. From 1999 to 2011, we collected 84 serum samples from 63 black bears (18 males; 45 females) in five Maryland counties and tested them for exposure to infectious, including zoonotic, pathogens. A large portion of the bears had antibody to canine distemper virus and Toxoplasma gondii, many at high titers. Prevalences of antibodies to zoonotic agents such as rabies virus and to infectious agents of carnivores including canine adenovirus and canine parvovirus were lower. Bears also had antibodies to vector-borne pathogens common to bears and humans such as West Nile virus, Borrelia burgdorferi, Rickettsia rickettsii, and Anaplasma phagocytophilum. Antibodies were detected to Leptospira interrogans serovars Pomona, Icterohaemorrhagiae, Canicola, Grippotyphosa, and Bratislava. We did not detect antibodies to Brucella canis or Ehrlichia canis. Although this population of Maryland black bears demonstrated exposure to multiple pathogens of concern for humans and domesticated animals, the low levels of clinical disease in this and other free-ranging black bear populations indicate the black bear is likely a spillover host for the majority of pathogens studied. Nevertheless, bear populations living at the human-domestic-wildlife interface with increasing human and domestic animal exposure should continue to be monitored because this population likely serves as a useful sentinel of ecosystem health.

  3. Social network analysis of mating patterns in American black bears (Ursus americanus).

    Science.gov (United States)

    Moore, Jennifer A; Xu, Ran; Frank, Kenneth; Draheim, Hope; Scribner, Kim T

    2015-08-01

    Nonrandom mating can structure populations and has important implications for population-level processes. Investigating how and why mating deviates from random is important for understanding evolutionary processes as well as informing conservation and management. Prior to the implementation of parentage analyses, understanding mating patterns in solitary, elusive species like bears was virtually impossible. Here, we capitalize on a long-term genetic data set collected from black bears (Ursus americanus) (N = 2422) in the Northern Lower Peninsula (NLP) of Michigan, USA. We identified mated pairs using parentage analysis and applied logistic regression (selection) models that controlled for features of the social network, to quantify the effects of individual characteristics, and spatial and population demographic factors on mating dynamics. Logistic regression models revealed that black bear mating was associated with spatial proximity of mates, male age, the time a pair had coexisted, local population density and relatedness. Mated pairs were more likely to contain older males. On average, bears tended to mate with nearby individuals to whom they were related, which does not support the existence of kin recognition in black bears. Pairwise relatedness was especially high for mated pairs containing young males. Restricted dispersal and high male turnover from intensive harvest mortality of NLP black bears are probably the underlying factors associated with younger male bears mating more often with female relatives. Our findings illustrate how harvest has the potential to disrupt the social structure of game species, which warrants further attention for conservation and management. © 2015 John Wiley & Sons Ltd.

  4. Effects of cooking on levels of PCBs in the fillets of winter flounder (Pseudopleuronectes americanus)

    Energy Technology Data Exchange (ETDEWEB)

    Poston, T.M. [Pacific Northwest Lab., Richland, WA (United States); Durell, G.S.; Koczwara, G.; Spellacy, A.M. [Battelle Ocean Sciences, Duxbury, MA (United States)

    1995-08-01

    The Pacific Northwest Laboratory and Battelle Ocean Sciences performed a study to determine the effect of cooking on polychlorinated biphenyl (PCB) levels in the fillets of winter flounder (Pseudopleuronectes americanus). Broiling, pan frying, and deep frying in oil were tested on fillets from 21 fish collected from New Bedford Harbor, Massachusetts, on February 21, 1991. The evaluation involved estimating the change in PCB concentrations using a mass-balance approach that factored the change in fillet weight resulting from cooking with the changes in PCB concentration expressed on a precooked wet-weight basis. Deep frying in oil resulted in a 47% reduction in total PCB levels in fillet tissue. Additionally, deep frying caused a 40% reduction in fillet mass. Pan frying and broiling resulted in statistically in insignificant increases in total PCB levels of 15% and 17%, respectively. Fillet mass reductions resulting from pan frying and broiling were 7% and 15%, respectively. The effects of cooking on 18 individual congeners generally paralleled the results observed for total PCB. All 18 congeners were significantly reduced by deep frying. Congener Cl{sub 2}(08) also was significantly reduced by either pan frying. Congeners Cl{sub 5}(105) and Cl{sub 5}(118) showed apparent significant increases in concentrations following pan frying. Congeners Cl{sub 5}(105), Cl{sub 5}(118), and C1{sub 6}(138) showed significant increases in concentration following broiling.

  5. American lobsters (Homarus americanus not surviving during air transport: evaluation of microbial spoilage

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    Erica Tirloni

    2016-05-01

    Full Text Available Eighteen American lobsters (Homarus americanus, dead during air transport, were analysed in order to evaluate the microbial population of meat, gills and gut: no specific studies have ever been conducted so far on the microbiological quality of American lobsters’ meats in terms of spoilage microbiota. The meat samples showed very limited total viable counts, in almost all the cases below the level of 6 Log CFU/g, while higher loads were found, as expected, in gut and gills, the most probable source of contamination. These data could justify the possibility to commercialise these notsurviving subjects, without quality concerns for the consumers. Most of the isolates resulted to be clustered with type strains of Pseudoalteromonas spp. (43.1% and Photobacterium spp. (24.1%, and in particular to species related to the natural marine environment. The distribution of the genera showed a marked inhomogeneity among the samples. The majority of the isolates identified resulted to possess proteolytic (69.3% and lipolytic ability (75.5%, suggesting their potential spoilage ability. The maintanance of good hygienical practices, especially during the production of ready-to-eat lobsters-based products, and a proper storage could limit the possible replication of these microorganisms.

  6. Experimental Infection and Detection of Necrotizing Hepatopancreatitis Bacterium in the American Lobster Homarus americanus

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    Luz A. Avila-Villa

    2012-01-01

    Full Text Available Necrotizing hepatopancreatitis bacterium (NHPB is an obligated intracellular bacteria causing severe hepatopancreatic damages and mass mortalities in penaeid shrimp. The worldwide distribution of penaeid shrimp as alien species threatens the life cycle of other crustacean species. The aim of the experiment was to evaluate the possibility of experimentally infecting the American lobster (Homarus americanus with NHPB extracted from shrimp hepatopancreas. Homogenates from infected shrimp were fed by force to lobsters. Other group of lobsters was fed with homogenates of NHPB-free hepatopancreas. After the 15th day from initial inoculation, the presence of NHPB was detected by polymerase chain reaction in feces and hepatopancreas from lobsters inoculated with infected homogenates. Necrotized spots were observed in the surface of lobster hepatopancreas. In contrast, lobsters fed on NHPB-free homogenates resulted negative for NHPB. Evidence suggests the plasticity of NHPB which can infect crustacean from different species and inhabiting diverse latitudes. Considering the results, the American lobster could be a good candidate to maintain available NHPB in vivo.

  7. Experimental Infection and Detection of Necrotizing Hepatopancreatitis Bacterium in the American Lobster Homarus americanus

    Science.gov (United States)

    Avila-Villa, Luz A.; Gollas-Galván, Teresa; Martínez-Porchas, Marcel; Mendoza-Cano, Fernando; Hernández-López, Jorge

    2012-01-01

    Necrotizing hepatopancreatitis bacterium (NHPB) is an obligated intracellular bacteria causing severe hepatopancreatic damages and mass mortalities in penaeid shrimp. The worldwide distribution of penaeid shrimp as alien species threatens the life cycle of other crustacean species. The aim of the experiment was to evaluate the possibility of experimentally infecting the American lobster (Homarus americanus) with NHPB extracted from shrimp hepatopancreas. Homogenates from infected shrimp were fed by force to lobsters. Other group of lobsters was fed with homogenates of NHPB-free hepatopancreas. After the 15th day from initial inoculation, the presence of NHPB was detected by polymerase chain reaction in feces and hepatopancreas from lobsters inoculated with infected homogenates. Necrotized spots were observed in the surface of lobster hepatopancreas. In contrast, lobsters fed on NHPB-free homogenates resulted negative for NHPB. Evidence suggests the plasticity of NHPB which can infect crustacean from different species and inhabiting diverse latitudes. Considering the results, the American lobster could be a good candidate to maintain available NHPB in vivo. PMID:22645497

  8. Excretory calcinosis: a new fatal disease of wild American lobsters Homarus americanus.

    Science.gov (United States)

    Dove, Alistair D M; LoBue, Carl; Bowser, Paul; Powell, Mark

    2004-03-10

    A significant number of moribund and dead lobsters Homarus americanus were reported to New York state authorities by lobster fishers in Long Island Sound (LIS) during the summer of 2002. Morbid lobsters were characterised by an orange discolouration of the abdomen, lethargy, an excess of epibionts and poor post-capture survival. On necropsy, severe extensive multifocal or diffuse mineralised granulomatous inflammation of the gills and antennal glands was the most striking pathology. In the gills, granulomas often occluded the lumen of filaments, resulting in congestion, ischemia and coagulative necrosis of gill tissues. In the antennal glands, granulomas were concentrated along the border between the coelomosac and labyrinth. No significant pathogens were recovered from diseased individuals. In prechronic individuals, however, it was evident that granulomas were focused around calcium carbonate (aragonite) crystals. This disease may result from anomalously high sea-bottom temperatures in LIS (approximately 23 degrees C) during the summer of 2002 and associated disruptions of the calcium chemistry of lobsters in favour of deposition of minerals in soft tissues. The ultimate cause of death of affected lobsters is probably respiratory failure due to reduced effective surface area of the gills, exacerbated by hypermetabolic temperatures and an abundance of epibionts.

  9. Bait and the susceptibility of American lobsters Homarus americanus to epizootic shell disease.

    Science.gov (United States)

    Bethoney, N David; Stokesbury, Kevin D E; Stevens, Bradley G; Altabet, Mark A

    2011-05-24

    Shell disease (SD) has been observed in lobster populations for almost a hundred years, but recently, rates of an epizootic form of shell disease (ESD) have increased in the southern New England (USA) area. A large proportion of fish in the diet of American lobsters Homarus americanus has been linked to increased rates of SD. Therefore, the use of fish as lobster bait may be linked to increased ESD rates in lobsters. Lobsters from the western portion of Martha's Vineyard, MA (41 degrees N, 71 degrees W), were randomly divided into 3 groups of 16 and exposed to dietary treatments (100% herring; 48% crab, 48% blue mussel and 4% plant matter; or 50% herring, 24% crab, 24% mussel, 2% plant matter) to determine if lobster tissue delta15N levels reflected diet. The results of the feeding experiment confirmed that differences in diet are observed in the delta15N levels of lobster muscle tissue. The delta15N levels of tissue samples from 175 wild lobsters with varying degrees of ESD were unrelated to ESD severity but did indicate lobsters were eating large amounts of fish (bait). This result does not support the speculation that fish used as bait is contributing to ESD outbreaks in portions of the southern New England area.

  10. American Lobsters (Homarus Americanus) not Surviving During Air Transport: Evaluation of Microbial Spoilage.

    Science.gov (United States)

    Tirloni, Erica; Stella, Simone; Gennari, Mario; Colombo, Fabio; Bernardi, Cristian

    2016-04-19

    Eighteen American lobsters ( Homarus americanus ), dead during air transport, were analysed in order to evaluate the microbial population of meat, gills and gut: no specific studies have ever been conducted so far on the microbiological quality of American lobsters' meats in terms of spoilage microbiota. The meat samples showed very limited total viable counts, in almost all the cases below the level of 6 Log CFU/g, while higher loads were found, as expected, in gut and gills, the most probable source of contamination. These data could justify the possibility to commercialise these not-surviving subjects, without quality concerns for the consumers. Most of the isolates resulted to be clustered with type strains of Pseudoalteromonas spp. (43.1%) and Photobacterium spp. (24.1%), and in particular to species related to the natural marine environment. The distribution of the genera showed a marked inhomogeneity among the samples. The majority of the isolates identified resulted to possess proteolytic (69.3%) and lipolytic ability (75.5%), suggesting their potential spoilage ability. The maintanance of good hygienical practices, especially during the production of ready-to-eat lobsters-based products, and a proper storage could limit the possible replication of these microorganisms.

  11. Genomic analysis of expressed sequence tags in American black bear Ursus americanus.

    Science.gov (United States)

    Zhao, Sen; Shao, Chunxuan; Goropashnaya, Anna V; Stewart, Nathan C; Xu, Yichi; Tøien, Øivind; Barnes, Brian M; Fedorov, Vadim B; Yan, Jun

    2010-03-26

    Species of the bear family (Ursidae) are important organisms for research in molecular evolution, comparative physiology and conservation biology, but relatively little genetic sequence information is available for this group. Here we report the development and analyses of the first large scale Expressed Sequence Tag (EST) resource for the American black bear (Ursus americanus). Comprehensive analyses of molecular functions, alternative splicing, and tissue-specific expression of 38,757 black bear EST sequences were conducted using the dog genome as a reference. We identified 18 genes, involved in functions such as lipid catabolism, cell cycle, and vesicle-mediated transport, that are showing rapid evolution in the bear lineage Three genes, Phospholamban (PLN), cysteine glycine-rich protein 3 (CSRP3) and Troponin I type 3 (TNNI3), are related to heart contraction, and defects in these genes in humans lead to heart disease. Two genes, biphenyl hydrolase-like (BPHL) and CSRP3, contain positively selected sites in bear. Global analysis of evolution rates of hibernation-related genes in bear showed that they are largely conserved and slowly evolving genes, rather than novel and fast-evolving genes. We provide a genomic resource for an important mammalian organism and our study sheds new light on the possible functions and evolution of bear genes.

  12. Modulation of gene expression in heart and liver of hibernating black bears (Ursus americanus).

    Science.gov (United States)

    Fedorov, Vadim B; Goropashnaya, Anna V; Tøien, Øivind; Stewart, Nathan C; Chang, Celia; Wang, Haifang; Yan, Jun; Showe, Louise C; Showe, Michael K; Barnes, Brian M

    2011-03-31

    Hibernation is an adaptive strategy to survive in highly seasonal or unpredictable environments. The molecular and genetic basis of hibernation physiology in mammals has only recently been studied using large scale genomic approaches. We analyzed gene expression in the American black bear, Ursus americanus, using a custom 12,800 cDNA probe microarray to detect differences in expression that occur in heart and liver during winter hibernation in comparison to summer active animals. We identified 245 genes in heart and 319 genes in liver that were differentially expressed between winter and summer. The expression of 24 genes was significantly elevated during hibernation in both heart and liver. These genes are mostly involved in lipid catabolism and protein biosynthesis and include RNA binding protein motif 3 (Rbm3), which enhances protein synthesis at mildly hypothermic temperatures. Elevated expression of protein biosynthesis genes suggests induction of translation that may be related to adaptive mechanisms reducing cardiac and muscle atrophies over extended periods of low metabolism and immobility during hibernation in bears. Coordinated reduction of transcription of genes involved in amino acid catabolism suggests redirection of amino acids from catabolic pathways to protein biosynthesis. We identify common for black bears and small mammalian hibernators transcriptional changes in the liver that include induction of genes responsible for fatty acid β oxidation and carbohydrate synthesis and depression of genes involved in lipid biosynthesis, carbohydrate catabolism, cellular respiration and detoxification pathways. Our findings show that modulation of gene expression during winter hibernation represents molecular mechanism of adaptation to extreme environments.

  13. Genomic analysis of expressed sequence tags in American black bear Ursus americanus

    Science.gov (United States)

    2010-01-01

    Background Species of the bear family (Ursidae) are important organisms for research in molecular evolution, comparative physiology and conservation biology, but relatively little genetic sequence information is available for this group. Here we report the development and analyses of the first large scale Expressed Sequence Tag (EST) resource for the American black bear (Ursus americanus). Results Comprehensive analyses of molecular functions, alternative splicing, and tissue-specific expression of 38,757 black bear EST sequences were conducted using the dog genome as a reference. We identified 18 genes, involved in functions such as lipid catabolism, cell cycle, and vesicle-mediated transport, that are showing rapid evolution in the bear lineage Three genes, Phospholamban (PLN), cysteine glycine-rich protein 3 (CSRP3) and Troponin I type 3 (TNNI3), are related to heart contraction, and defects in these genes in humans lead to heart disease. Two genes, biphenyl hydrolase-like (BPHL) and CSRP3, contain positively selected sites in bear. Global analysis of evolution rates of hibernation-related genes in bear showed that they are largely conserved and slowly evolving genes, rather than novel and fast-evolving genes. Conclusion We provide a genomic resource for an important mammalian organism and our study sheds new light on the possible functions and evolution of bear genes. PMID:20338065

  14. Anaerobic oral flora in the North American black bear (Ursus americanus) in eastern North Carolina.

    Science.gov (United States)

    Clarke, Elsburgh O; Stoskopf, Michael K; Minter, Larry J; Stringer, Elizabeth M

    2012-06-01

    Microbial flora can provide insight into the ecology and natural history of wildlife in addition to improving understanding of health risks. This study examines the anaerobic oral flora of hunter killed black bears (Ursus americanus) in eastern North Carolina. Oral swabs from the buccal and lingual supragingival tooth surfaces of the first and second mandibular and maxillary molars of 22 black bears were inoculated onto Brucella Blood Agar plates supplemented with hemin and vitamin K after transport from the field using reduced oxoid nutrient broth. Sixteen anaerobic bacterial species, representing nine genera were identified using the RapID ANA II Micromethod Kit system and a number of organisms grown that could not be identified with the system. The most frequently identified anaerobes were Peptostreptococcus prevotii, Streptococcus constellatus, and Porphyromonas gingivalis. The diversity in the anaerobic oral flora of black bear in eastern North Carolina suggests the importance of including these organisms in basic health risk assessment protocols and suggests a potential tool for assessment of bear/habitat interactions. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Temporal dynamics of genetic variability in a mountain goat (Oreamnos americanus) population.

    Science.gov (United States)

    Ortego, Joaquín; Yannic, Glenn; Shafer, Aaron B A; Mainguy, Julien; Festa-Bianchet, Marco; Coltman, David W; Côté, Steeve D

    2011-04-01

    The association between population dynamics and genetic variability is of fundamental importance for both evolutionary and conservation biology. We combined long-term population monitoring and molecular genetic data from 123 offspring and their parents at 28 microsatellite loci to investigate changes in genetic diversity over 14 cohorts in a small and relatively isolated population of mountain goats (Oreamnos americanus) during a period of demographic increase. Offspring heterozygosity decreased while parental genetic similarity and inbreeding coefficients (F(IS) ) increased over the study period (1995-2008). Immigrants introduced three novel alleles into the population and matings between residents and immigrants produced more heterozygous offspring than local crosses, suggesting that immigration can increase population genetic variability. The population experienced genetic drift over the study period, reflected by a reduced allelic richness over time and an 'isolation-by-time' pattern of genetic structure. The temporal decline of individual genetic diversity despite increasing population size probably resulted from a combination of genetic drift due to small effective population size, inbreeding and insufficient counterbalancing by immigration. This study highlights the importance of long-term genetic monitoring to understand how demographic processes influence temporal changes of genetic diversity in long-lived organisms. © 2011 Blackwell Publishing Ltd.

  16. Vias bilíferas no tapir ou anta (Tapirus americanus

    Directory of Open Access Journals (Sweden)

    Maria Angélica Miglino

    1994-06-01

    Full Text Available Os autores estudaram as vias bilíferas do tapir ou anta (Tapirus americanus, após injeção do sistema excretor do fígado de 2 animais, machos e adultos, com látex Neoprene 650 corado, fixação das peças com solução aquosa de formol a 10% e dissecação. O ductus choledocus origina-se a partir da confluência do ramus principalis dexter e do sinister, sendo este animal desprovido de vesícula biliar. O ramus principalis dexter é formado pelos ramus ventralis lobi dextri, ramus medius lobi dextri, ramus dorsalis lobi dextri e ramus processi caudati, os quais se unem por diferentes modalidades. O ramus principalis sinister é formado pelos ramus medius lobi sinistri lateralis, ramus dorsalis lobi sinistri lateralis, ramus lobi quadrati, ramus ventralis lobi sinistri lateralis e ramus lobi sinistri medialis, com diferentes arranjos

  17. 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,...

  18. 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

  19. Reply to the comment by U. Leonhardt on “Aharonov-Bohm scattering of neutral atoms with induced electric dipole moments”

    Science.gov (United States)

    Audretsch, Jürgen; Skarzhinsky, Vladimir D.

    1999-03-01

    We reply to the comment of Leonhardt [Phys. Lett. A 253 (1999) 370] on our paper [Phys. Lett. A 241 (1998) 7]. The partial-wave approach can be adjusted to the Aharanov-Bohm scattering. For the scattering of neutral atoms, it enables the treatment of total absorption in a consistent way.

  20. Population biology and diet of the southern kingcroaker Menticirrhus americanus (Linnaeus, 1758 (Perciformes: Sciaenidae in Caraguatatuba Bay, southeastern Brazil

    Directory of Open Access Journals (Sweden)

    Alexander Turra

    2012-09-01

    Full Text Available This study evaluated the spatio-temporal distribution, population biology and diet of Menticirrhus americanus in Caraguatatuba Bay. Samples were taken monthly between August 2003 and October 2004, by trawling in two previously selected areas. The northern area is more exposed to wave activity and is influenced by a river, functioning as a small estuary. In contrast, the southern area is relatively sheltered from wave energy and influenced to a lesser degree by smaller rivers. The fishes' length was measured, and the sex and gonadal stage macroscopically identified. The abundance of this species was compared between areas and among months. The diet was identified and quantified. M. americanus occurred in equal proportions in the two study areas, being most abundant in April 2004, followed by December 2003 and January 2004. The population was dominated by small immature individuals. The few individuals in maturation or mature that were captured showed no seasonal pattern of distribution. This species had a varied diet, feeding on worms (nemerteans, sipunculans and echiurans, mollusks (bivalves and cephalopods, polychaetes, crustaceans and fish. The presence of intact nematodes in the intestine suggests that these are parasites. The results demonstrated that M. americanus has a homogeneous spatial and temporal distribution in Caraguatatuba Bay, being uniformly distributed between the south and north areas as well as across the months. This species can be considered a carnivorous predator, showing a preference for consuming benthic sandy-beach species such as glycerids and other polychaetes, crustaceans, and bivalve siphons.Este estudo teve como objetivo avaliar a distribuição espaço-temporal, biologia populacional e dieta de Menticirrhus americanus da baía de Caraguatatuba. Foram realizadas coletas mensais entre agosto de 2003 a outubro de 2004, utilizando redes de arrasto em duas áreas previamente selecionadas. A área norte é mais expostas

  1. Electromagnetic disturbance neutralizing radiation detector

    International Nuclear Information System (INIS)

    Gripentog, W.G.

    1975-01-01

    A radiation detector of the Neher-White type is described which automatically neutralizes induced negative charges on the electrometer tube control grid which shut off the electrometer tube. The detector includes means for establishing a voltage of one polarity in response to plate current and voltage of opposite polarity in response to an absence of plate current and means for connecting the control grid to a reference potential for draining the negative charge in response to the voltage of opposite polarity. (author)

  2. Effects of starvation on moult cycle and hepatopancreas of Stage I lobster (Homarus americanus) larvae

    Science.gov (United States)

    Anger, K.; Storch, V.; Anger, V.; Capuzzo, J. M.

    1985-06-01

    Effects of feeding and starvation on the moult cycle and on the ultrastructure of hepatopancreas cells were studied in Stage I lobster larvae ( Homarus americanus Milne-Edwards). The relative significance of yolk and first food was quite different in larvae originating from two females. This difference was evident also in the amounts of stored lipid in the R-cells of the larval hepatopancreas. Most larvae from one hatch were, in principle, able to develop exclusively with yolk reserves (without food) to the second instar. The larvae from the second hatch showed lecithotrophic development only to the transition between late intermoult and early premoult (Stages C/D0 of Drachs's moult cycle) of the first larval instar. When initial starvation in this group lasted for 3 days or more, the point of no return (PNR) was exceeded. After the PNR, consumption of food was still possible, but development ceased in the transition C/D0 or in late premoult (D3 4). It is suggested that these stages of the moult cycle are critical points were cessation of development and increased mortality are particularly likely in early larval lobsters under nutritional stress. Examination of hepatopancreas R-cells suggested that the PNR is caused by an irreversible loss of the ability to restore lipid reserves depleted during initial starvation. Initial periods of starvation ending before the PNR prolonged mainly Stage D0 of the same instar (I). During this delay, structural changes in the R-cells caused by the preceding period of starvation were reversed: reduced lipid inclusions, swollen mitochondria, an increased number of residual bodies indicating autolysis, and a reduction of the microvillous processes. Continually starved larvae which showed lecithotrophic development throughout the first instar and were then re-fed after moulting successfully, had later a prolonged intermoult (Stage C) period in the second instar. This shows that, despite occasional lecithotrophy, food is an important

  3. PREVALENCE OF BABESIA SPP., EHRLICHIA SPP., AND TICK INFESTATIONS IN OKLAHOMA BLACK BEARS (URSUS AMERICANUS).

    Science.gov (United States)

    Skinner, Delaina; Mitcham, Jessica R; Starkey, Lindsay A; Noden, Bruce H; Fairbanks, W Sue; Little, Susan E

    2017-10-01

    American black bears (Ursus americanus) are commonly infested with ticks throughout their range, but there are few surveys for tick-borne disease agents in bears. To characterize tick infestations and determine the prevalence of current infection with Babesia spp. and past or current infection with Ehrlichia spp. in newly re-established populations of black bears in east central and southeastern Oklahoma, US, we identified adult (n=1,048) and immature (n=107) ticks recovered from bears (n=62). We evaluated serum and whole blood samples from a subset (n=49) for antibodies reactive to, and characteristic DNA fragments of, Ehrlichia spp., as well as characteristic DNA fragments of Babesia spp. Amblyomma americanum, the most common tick identified, was found on a majority (56/62; 90%) of bears and accounted for 697/1,048 (66.5%) of all ticks recovered. Other ticks included Dermacentor variabilis (338/1,048; 32.3%) from 36 bears, Amblyomma maculatum (9/1,048; 0.9%) from three bears, and Ixodes scapularis (4/1,048; 0.4%) from three bears. Antibodies reactive to Ehrlichia spp. were detected in every bear tested (49/49; 100%); maximum inverse titers to Ehrlichia chaffeensis ranged from 64-4,096 (geometric mean titer 1,525). However, PCR failed to identify active infection with E. chaffeensis, Ehrlichia ewingii, or an Ehrlichia ruminantium-like agent. Infection with Babesia spp. was detected by PCR in 3/49 (6%) bears. Together these data confirm that tick infestations and infection with tick-borne disease agents are common in bears in the southern US. The significance of these infestations and infections to the health of bears, if any, and the identity of the Ehrlichia spp. responsible for the antibody reactivity seen, warrant further evaluation.

  4. Detection of human bacterial pathogens in ticks collected from Louisiana black bears (Ursus americanus luteolus).

    Science.gov (United States)

    Leydet, Brian F; Liang, Fang-Ting

    2013-04-01

    There are 4 major human-biting tick species in the northeastern United States, which include: Amblyomma americanum, Amblyomma maculatum, Dermacentor variabilis, and Ixodes scapularis. The black bear is a large mammal that has been shown to be parasitized by all the aforementioned ticks. We investigated the bacterial infections in ticks collected from Louisiana black bears (Ursus americanus subspecies luteolus). Eighty-six ticks were collected from 17 black bears in Louisiana from June 2010 to March 2011. All 4 common human-biting tick species were represented. Each tick was subjected to polymerase chain reaction (PCR) targeting select bacterial pathogens and symbionts. Bacterial DNA was detected in 62% of ticks (n=53). Rickettsia parkeri, the causative agent of an emerging spotted fever group rickettsiosis, was identified in 66% of A. maculatum, 28% of D. variabilis, and 11% of I. scapularis. The Lyme disease bacterium, Borrelia burgdorferi, was detected in 2 I. scapularis, while one A. americanum was positive for Borrelia bissettii, a putative human pathogen. The rickettsial endosymbionts Candidatus Rickettsia andeanae, rickettsial endosymbiont of I. scapularis, and Rickettsia amblyommii were detected in their common tick hosts at 21%, 39%, and 60%, respectively. All ticks were PCR-negative for Anaplasma phagocytophilum, Ehrlichia spp., and Babesia microti. This is the first reported detection of R. parkeri in vector ticks in Louisiana; we also report the novel association of R. parkeri with I. scapularis. Detection of both R. parkeri and B. burgdorferi in their respective vectors in Louisiana demands further investigation to determine potential for human exposure to these pathogens. Copyright © 2013 Elsevier GmbH. All rights reserved.

  5. Blood lipid concentrations and lipoprotein patterns in captive and wild American black bears (Ursus americanus).

    Science.gov (United States)

    Frank, Nicholas; Elliott, Sarah B; Allin, Shawn B; Ramsay, Edward C

    2006-02-01

    To compare blood lipid concentrations and lipoprotein patterns for captive and wild American black bears (Ursus americanus). 7 captive and 9 wild adult (> or = 4 years old) black bears. Blood was collected from 2 groups of captive black bears (groups A and B) and 1 group of wild black bears (group C). Blood triglyceride (TG) and cholesterol concentrations were compared among groups. Plasma lipoproteins were isolated by use of a self-generating gradient of iodixanol, and lipoprotein patterns were compared between groups A and B. Captive bears (mean +/- SD, 187.8 +/- 44.4 kg) weighed significantly more than wild bears (mean, 104.8 +/- 41.4 kg), but mean body weight did not differ between groups A and B. Mean blood TG concentrations for groups B (216.8 +/- 16.0 mg/dL) and C (190.7 +/- 34.0 mg/dL) were significantly higher than that of group A (103.9 +/- 25.3 mg/dL). Mean blood cholesterol concentration was also significantly higher for group B (227.8 +/- 8.2 mg/dL) than for groups A (171.7 +/- 35.5 mg/dL) or C (190.8 +/- 26.8 mg/dL). Mean very-low-density lipoprotein TG and low-density lipoprotein cholesterol concentrations were 2- and 3-fold higher, respectively, for group B, compared with concentrations for group A. Blood lipid concentrations vary significantly among populations of black bears. Plasma lipoprotein patterns of captive bears differed significantly between colonies and may have reflected differences in diet or management practices.

  6. Modulation of gene expression in heart and liver of hibernating black bears (Ursus americanus

    Directory of Open Access Journals (Sweden)

    Yan Jun

    2011-03-01

    Full Text Available Abstract Background Hibernation is an adaptive strategy to survive in highly seasonal or unpredictable environments. The molecular and genetic basis of hibernation physiology in mammals has only recently been studied using large scale genomic approaches. We analyzed gene expression in the American black bear, Ursus americanus, using a custom 12,800 cDNA probe microarray to detect differences in expression that occur in heart and liver during winter hibernation in comparison to summer active animals. Results We identified 245 genes in heart and 319 genes in liver that were differentially expressed between winter and summer. The expression of 24 genes was significantly elevated during hibernation in both heart and liver. These genes are mostly involved in lipid catabolism and protein biosynthesis and include RNA binding protein motif 3 (Rbm3, which enhances protein synthesis at mildly hypothermic temperatures. Elevated expression of protein biosynthesis genes suggests induction of translation that may be related to adaptive mechanisms reducing cardiac and muscle atrophies over extended periods of low metabolism and immobility during hibernation in bears. Coordinated reduction of transcription of genes involved in amino acid catabolism suggests redirection of amino acids from catabolic pathways to protein biosynthesis. We identify common for black bears and small mammalian hibernators transcriptional changes in the liver that include induction of genes responsible for fatty acid β oxidation and carbohydrate synthesis and depression of genes involved in lipid biosynthesis, carbohydrate catabolism, cellular respiration and detoxification pathways. Conclusions Our findings show that modulation of gene expression during winter hibernation represents molecular mechanism of adaptation to extreme environments.

  7. Incorporating Road Crossing Data into Vehicle Collision Risk Models for Moose (Alces americanus) in Massachusetts, USA.

    Science.gov (United States)

    Zeller, Katherine A; Wattles, David W; DeStefano, Stephen

    2018-05-09

    Wildlife-vehicle collisions are a human safety issue and may negatively impact wildlife populations. Most wildlife-vehicle collision studies predict high-risk road segments using only collision data. However, these data lack biologically relevant information such as wildlife population densities and successful road-crossing locations. We overcome this shortcoming with a new method that combines successful road crossings with vehicle collision data, to identify road segments that have both high biological relevance and high risk. We used moose (Alces americanus) road-crossing locations from 20 moose collared with Global Positioning Systems as well as moose-vehicle collision (MVC) data in the state of Massachusetts, USA, to create multi-scale resource selection functions. We predicted the probability of moose road crossings and MVCs across the road network and combined these surfaces to identify road segments that met the dual criteria of having high biological relevance and high risk for MVCs. These road segments occurred mostly on larger roadways in natural areas and were surrounded by forests, wetlands, and a heterogenous mix of land cover types. We found MVCs resulted in the mortality of 3% of the moose population in Massachusetts annually. Although there have been only three human fatalities related to MVCs in Massachusetts since 2003, the human fatality rate was one of the highest reported in the literature. The rate of MVCs relative to the size of the moose population and the risk to human safety suggest a need for road mitigation measures, such as fencing, animal detection systems, and large mammal-crossing structures on roadways in Massachusetts.

  8. Structural and functional characterization of a multifunctional alanine-rich peptide analogue from Pleuronectes americanus.

    Directory of Open Access Journals (Sweden)

    Ludovico Migliolo

    Full Text Available Recently, defense peptides that are able to act against several targets have been characterized. The present work focuses on structural and functional evaluation of the peptide analogue Pa-MAP, previously isolated as an antifreeze peptide from Pleuronectes americanus. Pa-MAP showed activities against different targets such as tumoral cells in culture (CACO-2, MCF-7 and HCT-116, bacteria (Escherichia coli ATCC 8739 and Staphylococcus aureus ATCC 25923, viruses (HSV-1 and HSV-2 and fungi (Candida parapsilosis ATCC 22019, Trichophyton mentagrophytes (28d&E and T. rubrum (327. This peptide did not show toxicity against mammalian cells such as erythrocytes, Vero and RAW 264.7 cells. Molecular mechanism of action was related to hydrophobic residues, since only the terminal amino group is charged at pH 7 as confirmed by potentiometric titration. In order to shed some light on its structure-function relations, in vitro and in silico assays were carried out using circular dichroism and molecular dynamics. Furthermore, Pa-MAP showed partial unfolding of the peptide changes in a wide pH (3 to 11 and temperature (25 to 95°C ranges, although it might not reach complete unfolding at 95°C, suggesting a high conformational stability. This peptide also showed a conformational transition with a partial α-helical fold in water and a full α-helical core in SDS and TFE environments. These results were corroborated by spectral data measured at 222 nm and by 50 ns dynamic simulation. In conclusion, data reported here show that Pa-MAP is a potential candidate for drug design against pathogenic microorganisms due to its structural stability and wide activity against a range of targets.

  9. Human Papillomavirus neutralizing and cross-reactive antibodies induced in HIV-positive subjects after vaccination with quadrivalent and bivalent HPV vaccines

    DEFF Research Database (Denmark)

    Faust, Helena; Nielsen, Lars Toft; Sehr, Peter

    2016-01-01

    Ninety-one HIV-infected individuals (61 men and 30 women) were randomized to vaccination either with quadrivalent (Gardasil™) or bivalent (Cervarix™) HPV vaccine. Neutralizing and specific HPV-binding serum antibodies were measured at baseline and 12 months after the first vaccine dose. Presence...... of neutralizing and binding antibodies had good agreement (average Kappa for HPV types 6, 11, 16, 18, 31, 33 and 45 was 0.65). At baseline, 88% of subjects had antibodies against at least one genital HPV. Following vaccination with Cervarix™, all subjects became seropositive for HPV16 and 18. After Gardasil......™ vaccination, 96% of subjects seroconverted for HPV16 and 73% for HPV18. Levels of HPV16-specific antibodies were 10IU in 85% of study subjects after vaccination. Antibodies against non-vaccine HPV types appeared after Gardasil...

  10. First measurements of the neutrals pressure and of the degassing level of the lower hybrid antenna induced by the HF power

    International Nuclear Information System (INIS)

    Goniche, M.; Berger-By, G.; Bibet, P.; Bonnel, P.; Bruneau, J.L.; Capitain, J.J.; Gil, C.; Hertout, P.; Rodriguez, L.; Magne, R.

    1989-12-01

    Previous experiments have shown that large amounts of gas may be desorbed from the waveguides walls of a lower hybrid antenna. To reduce the pressure rise, a getter pump has been connected to the LH vessel of Tore Supra. The effective neutrals pumping speed of the LH launcher during a plasma shot has been measured for different configurations of the getter pump (inactive, low conductance and high conductance duct). For deuterium, an effective pumping speed of 33 m 3 /s was obtained. During short conditioning pulses and 2-s plasma shots, degassing rates were measured for RF power level up to 1.2 MW. With different filling gas (He, H 2 , D 2 ), degassing rates are documented and effects of conditioning are discussed. This neutrals influx contributes to the particles balance of the plasma discharge: a significant increase of the total number of particles (10-20%) and a flattening of the density profile are inferred. Large increase of the neutrals pressure in the pumped limitor (up to 32%) was also observed. For 2-s shots, this pressure rise was held below 3 mPa at an average LH power density of 1.5 kW/cm 2 . However, this pressure rise may be, to some extent, larger in the reduced-section part of the launcher which has a low conductance. It is expected that this pressure rise should not exceed 5 mPa at full power (5 KW/cm 2 ) after conditioning [fr

  11. Collision-Induced Dissociation of Deprotonated Peptides. Relative Abundance of Side-Chain Neutral Losses, Residue-Specific Product Ions, and Comparison with Protonated Peptides.

    Science.gov (United States)

    Liang, Yuxue; Neta, Pedatsur; Yang, Xiaoyu; Stein, Stephen E

    2018-03-01

    High-accuracy MS/MS spectra of deprotonated ions of 390 dipeptides and 137 peptides with three to six residues are studied. Many amino acid residues undergo neutral losses from their side chains. The most abundant is the loss of acetaldehyde from threonine. The abundance of losses from the side chains of other amino acids is estimated relative to that of threonine. While some amino acids lose the whole side chain, others lose only part of it, and some exhibit two or more different losses. Side-chain neutral losses are less abundant in the spectra of protonated peptides, being significant mainly for methionine and arginine. In addition to the neutral losses, many amino acid residues in deprotonated peptides produce specific negative ions after peptide bond cleavage. An expanded list of fragment ions from protonated peptides is also presented and compared with those of deprotonated peptides. Fragment ions are mostly different for these two cases. These lists of fragments are used to annotate peptide mass spectral libraries and to aid in the confirmation of specific amino acids in peptides. Graphical Abstract ᅟ.

  12. On neutral plasma oscillations

    International Nuclear Information System (INIS)

    Shadwick, B.A.; Morrison, P.J.

    1993-06-01

    We examine the conditions for the existence of spectrally stable neutral modes in a Vlasov-Poisson plasma and show that for stable equilibria of systems that have unbounded spatial domain, the only possible neutral modes are those with phase velocities that correspond to stationary inflection points of the equilibrium distribution function. It is seen that these neutral modes can possess positive or negative free energy

  13. Neutral beam monitoring

    International Nuclear Information System (INIS)

    Fink, J.H.

    1979-01-01

    A neutral beam generated by passing accelerated ions through a walled cell containing a low energy neutral gas, such that charge exchange partially neutralizes the high energy beam, is monitored by detecting the current flowing through the cell wall produced by low energy ions which drift to the wall after the charge exchange. By segmenting the wall into radial and longitudinal segments various beam conditions are identified. (U.K.)

  14. On neutral plasma oscillations

    International Nuclear Information System (INIS)

    Shadwick, B.A.; Texas Univ., Austin; Morrison, P.J.; Texas Univ., Austin

    1994-01-01

    We examine the conditions for the existence of spectrally stable neutral modes in a Vlasov-Poisson plasma and show that for stable equilibria of systems that have unbounded spatial domain, the only possible neutral modes are those with phase velocities that correspond to stationary inflection points of the equilibrium distribution function. It is seen that these neutral modes can posses positive or negative free energy. (orig.)

  15. Efficacy of IgG and F(ab′)2 Antivenoms to Neutralize Snake Venom-induced Local Tissue Damage as Assessed by the Proteomic Analysis of Wound Exudate

    OpenAIRE

    Rucavado, Alexandra; Escalante Muñoz, Teresa; Shannon, John D.; Ayala Castro, Carla N.; Villalta, Mauren; Gutiérrez, José María; Fox, Jay W.

    2012-01-01

    2082-01 Embargo por política editorial Proteomic analysis of wound exudates represents a valuable tool to investigate tissue pathology and to assess the therapeutic success of various interventions. In this study, the ability of horse-derived IgG and F(ab0)2 antivenoms to neutralize local pathological effects induced by the venom of the snake Bothrops asper in mouse muscle was investigated by the proteomic analysis of exudates collected in the vicinity of affected tissue. In experiments...

  16. Search for neutral leptons

    International Nuclear Information System (INIS)

    Perl, M.L.

    1984-12-01

    At present we know of three kinds of neutral leptons: the electron neutrino, the muon neutrino, and the tau neutrino. This paper reviews the search for additional neutral leptons. The method and significance of a search depends upon the model used for the neutral lepton being sought. Some models for the properties and decay modes of proposed neutral leptons are described. Past and present searches are reviewed. The limits obtained by some completed searches are given, and the methods of searches in progress are described. Future searches are discussed. 41 references

  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. Evaluation of smallpox vaccines using variola neutralization.

    Science.gov (United States)

    Damon, Inger K; Davidson, Whitni B; Hughes, Christine M; Olson, Victoria A; Smith, Scott K; Holman, Robert C; Frey, Sharon E; Newman, Frances; Belshe, Robert B; Yan, Lihan; Karem, Kevin

    2009-08-01

    The search for a 'third'-generation smallpox vaccine has resulted in the development and characterization of several vaccine candidates. A significant barrier to acceptance is the absence of challenge models showing induction of correlates of protective immunity against variola virus. In this light, virus neutralization provides one of few experimental methods to show specific 'in vitro' activity of vaccines against variola virus. Here, we provide characterization of the ability of a modified vaccinia virus Ankara vaccine to induce variola virus-neutralizing antibodies, and we provide comparison with the neutralization elicited by standard Dryvax vaccination.

  19. 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

  20. Colonization of dodder, Cuscuta indecora, by 'Candidatus Liberibacter asiaticus' and 'Ca. L. americanus'.

    Science.gov (United States)

    Hartung, John S; Paul, Cristina; Achor, Diann; Brlansky, R H

    2010-08-01

    Huanglongbing, or citrus greening, threatens the global citrus industry. The presumptive pathogens, 'Candidatus Liberibacter asiaticus' and 'Ca. L. americanus' can be transferred from citrus to more easily studied experimental hosts by using holoparasitic dodder plants. However, the interaction between 'Candidatus Liberibacter' spp. and the dodder has not been studied. We combined quantitative polymerase chain reaction with electron microscopy to show that only 65% of tendrils of Cuscuta indecora grown on 'Ca. Liberibacter' spp.-infected host plants had detectable levels of the pathogen. Among tendrils that were colonized by Liberibacter in at least one 2 cm segment, most were not colonized in all segments. Furthermore, the estimated population levels of the pathogen present in serial 2 cm segments of dodder tendrils varied widely and without any consistent pattern. Thus, there was generally not a concentration gradient of the pathogen from the source plant towards the recipient and populations of the pathogen were sometimes found in the distal segments of the dodder plant but not in the proximal or middle segments. Populations of the pathogens ranged from 2 x 10(2) to 3.0 x 10(8) cells per 2 cm segment. On a fresh weight basis, populations as high as 1.4 x 10(10) cells per g of tissue were observed demonstrating that 'Ca. Liberibacter' spp. multiplies well in Cuscuta indecora. However, 55% of individual stem segments did not contain detectable levels of the pathogen, consistent with a pattern of nonuniform colonization similar to that observed in the much more anatomically complex citrus tree. Colonization of dodder by the pathogen is also nonuniform at the ultrastructural level, with adjacent phloem vessel elements being completely full of the pathogen or free of the pathogen. We also observed bacteria in the phloem vessels that belonged to two distinct size classes based on the diameters of cross sections of cells. In other sections from the same tendrils we

  1. Dental and Temporomandibular Joint Pathology of the American Black Bear (Ursus americanus).

    Science.gov (United States)

    Clark, E J; Chesnutt, S R; Winer, J N; Kass, P H; Verstraete, F J M

    Museum specimens (maxillae and/or mandibles) from 371 American black bears (Ursus americanus) acquired between 1889 and 2006 were examined macroscopically according to predefined criteria, and 348 were included in this study. Of the 348 specimens, 126 (36.2%) were from male animals, 106 (30.5%) were from female animals and 116 (33.3%) were from animals of unknown sex. Specimen ages ranged from young adult (n = 63, 18.1%) to adult (n = 285, 81.9%), with juveniles excluded from the study. The number of teeth available for examination was 12,019 (82.2%); 7.0% of teeth were absent artefactually, 0.4% were deemed absent due to acquired tooth loss and 9.7% were absent congenitally. In 43 specimens (12.3%), 82 teeth (0.68%) were small vestigial structures with crowns that were flush with the level of surrounding alveolar bone. The remaining teeth (99.3%) were of normal morphology. Only three supernumerary teeth and three instances of enamel hypoplasia were encountered. Persistent deciduous teeth or teeth with an aberrant number of roots were not encountered in any of the specimens. Approximately one-third of the teeth examined (4,543, 37.8%) displayed attrition/abrasion, affecting nearly all of the specimens (n = 338, 97.1%). Incisor and molar teeth accounted for 52.5% and 34.3% of the affected teeth, respectively, with significantly more adults affected than young adults. Dental fractures were noted in 63 bears, affecting 18.1% of specimens and 1.0% of the total number of present teeth. The canine teeth were most often fractured, with adults having significantly more complicated crown fractures of these teeth than young adults. There were 11 specimens (3.2%) that displayed periapical lesions, affecting 12 (0.1%) dental alveoli. There were 179 specimens (51.4%) displaying bony changes indicative of periodontitis, affecting 816 (6.8%) dental alveoli. The proportion of adult bears affected by periodontitis (57.9%) was significantly greater than that of young adults

  2. Immunization of rabbits with highly purified, soluble, trimeric human immunodeficiency virus type 1 envelope glycoprotein induces a vigorous B cell response and broadly cross-reactive neutralization.

    Directory of Open Access Journals (Sweden)

    Gerald V Quinnan

    Full Text Available Previously we described induction of cross-reactive HIV-1 neutralizing antibody responses in rabbits using a soluble HIV-1 gp140 envelope glycoprotein (Env in an adjuvant containing monophosphoryl lipid A (MPL and QS21 (AS02A. Here, we compared different forms of the same HIV-1 strain R2 Env for antigenic and biophysical characteristics, and in rabbits characterized the extent of B cell induction for specific antibody expression and secretion and neutralizing responses. The forms of this Env that were produced in and purified from stably transformed 293T cells included a primarily dimeric gp140, a trimeric gp140 appended to a GCN4 trimerization domain (gp140-GCN4, gp140-GCN4 with a 15 amino acid flexible linker between the gp120 and gp41 ectodomain (gp140-GCN4-L, also trimeric, and a gp140 with the flexible linker purified from cell culture supernatants as either dimer (gp140-L(D or monomer (gp140-L(M. Multimeric states of the Env proteins were assessed by native gel electrophoresis and analytical ultracentrifugation. The different forms of gp140 bound broadly cross-reactive neutralizing (BCN human monoclonal antibodies (mAbs similarly in ELISA and immunoprecipitation assays. All Envs bound CD4i mAbs in the presence and absence of sCD4, as reported for the R2 Env. Weak neutralization of some strains of HIV-1 was seen after two additional doses in AS02A. Rabbits that were given a seventh dose of gp140-GCN4-L developed BCN responses that were weak to moderate, similar to our previous report. The specificity of these responses did not appear similar to that of any of the known BCN human mAbs. Induction of spleen B cell and plasma cells producing immunoglobulins that bound trimeric gp140-GCN4-L was vigorous, based on ELISpot and flow cytometry analyses. The results demonstrate that highly purified gp140-GCN4-L trimer in adjuvant elicits BCN responses in rabbits accompanied by vigorous B cell induction.

  3. Use of acepromazine and medetomidine in combination for sedation and handling of Rocky Mountain elk (Cervus elaphus nelsoni) and black bears (Ursus americanus).

    Science.gov (United States)

    Wolfe, Lisa L; Johnson, Heather E; Fisher, Mark C; Sirochman, Michael A; Kraft, Benjamin; Miller, Michael W

    2014-10-01

    We opportunistically evaluated a combination of acepromazine maleate and medetomidine HCl for use in sedating Rocky Mountain elk (Cervus elaphus nelsoni) and black bears (Ursus americanus) as an alternative to scheduled drug combinations. This combination was safe and effective with limitations inherent in its sedative rather than anesthetic properties.

  4. Antibodies induced by vaccination with purified chick embryo cell culture vaccine (PCECV) cross-neutralize non-classical bat lyssavirus strains.

    Science.gov (United States)

    Malerczyk, Claudius; Selhorst, Thomas; Tordo, Noël; Moore, Susan; Müller, Thomas

    2009-08-27

    Tissue-culture vaccines like purified chick embryo cell vaccine (PCECV) have been shown to provide protection against classical rabies virus (RABV) via pre-exposure or post-exposure prophylaxis. A cross-neutralization study was conducted using a panel of 100 human sera, to determine, to what extent after vaccination with PCECV protection exists against non-classical bat lyssavirus strains like European bat lyssavirus (EBLV) type 1 and 2 and Australian bat lyssavirus (ABLV). Virus neutralizing antibody (VNA) concentrations against the rabies virus variants CVS-11, ABLV, EBLV-1 and EBLV-2 were determined by using a modified rapid fluorescent focus inhibition test. For ABLV and EBLV-2, the comparison to CVS-11 revealed almost identical results (100% adequate VNA concentrations >or=0.5 IU/mL; correlation coefficient r(2)=0.69 and 0.77, respectively), while for EBLV-1 more scattering was observed (97% adequate VNA concentrations; r(2)=0.50). In conclusion, vaccination with PCECV produces adequate VNA concentrations against classical RABV as well as non-classical lyssavirus strains ABLV, EBLV-1, and EBLV-2.

  5. Neutralized transport experiment

    International Nuclear Information System (INIS)

    Roy, P.K.; Yu, S.S.; Eylon, S.; Henestroza, E.; Anders, A.; Gilson, E.P.; Bieniosek, F.M.; Greenway, W.G.; Logan, B.G.; Waldron, W.L.; Shuman, D.B.; Vanecek, D.L.; Welch, D.R.; Rose, D.V.; Thoma, C.; Davidson, R.C.; Efthimion, P.C.; Kaganovich, I.; Sefkow, A.B.; Sharp, W.M.

    2005-01-01

    Experimental details on providing active neutralization of high brightness ion beam have been demonstrated for Heavy Ion Fusion program. A K + beam was extracted from a variable-perveance injector and transported through 2.4 m long quadrupole lattice for final focusing. Neutralization was provided by a localized cathode arc plasma plug and a RF volume plasma system. Effects of beam perveance, emittance, convergence focusing angle, and axial focusing position on neutralization have been investigated. Good agreement has been observed with theory and experiment throughout the study

  6. Are "Market Neutral" Hedge Funds Really Market Neutral?

    OpenAIRE

    Andrew J. Patton

    2009-01-01

    Using a variety of different definitions of "neutrality," this study presents significant evidence against the neutrality to market risk of hedge funds in a range of style categories. I generalize standard definitions of "market neutrality," and propose five different neutrality concepts. I suggest statistical tests for each neutrality concept, and apply these tests to a database of monthly returns on 1423 hedge funds from five style categories. For the "market neutral" style, approximately o...

  7. 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.

  8. Bunched beam neutralization

    International Nuclear Information System (INIS)

    Gammel, G.M.; Maschke, A.W.; Mobley, R.M.

    1979-01-01

    One of the steps involved in producing an intense ion beam from conventional accelerators for Heavy Ion Fusion (HIF) is beam bunching. To maintain space charge neutralized transport, neutralization must occur more quickly as the beam bunches. It has been demonstrated at BNL that a 60 mA proton beam from a 750 kV Cockcroft--Walton can be neutralized within a microsecond. The special problem in HIF is that the neutralization must occur in a time scale of nanoseconds. To study neutralization on a faster time scale, a 40 mA, 450 kV proton beam was bunched at 16 MHz. A biased Faraday cup sampled the bunched beam at the position where maximum bunching was nominally expected, about 2.5 meters from the buncher. Part of the drift region, about 1.8 meters, was occupied by a series of Gabor lenses. In addition to enhancing beam transport by transverse focussing, the background cloud of electrons in the lenses provided an extra degree of neutralization. With no lens, the best bunch factor was at least 20. Bunch factor is defined here as the ratio of the distance between bunches to the FWHM bunch length. With the lens, it was hoped that the increased plasma frequency would decrease the neutralization time and cause an increase in the bunch factor. In fact, with the lens, the instantaneous current increased about three times, but the bunch factor dropped to about 10. Even with the lens, the FWHM of the bunches at the position of maximum bunching was still comparable to or less than the oscillation period of the surrounding electron plasma. Thus, the electron density in the lens must increase before neutralization could be effective in this case, or bunching should be done at a lower frequency

  9. Persistent Bovine Viral Diarrhea Virus infection in domestic and wild small ruminants and camelids including the mountain goat (Oreamnos americanus

    Directory of Open Access Journals (Sweden)

    Danielle Darracq Nelson

    2016-01-01

    Full Text Available Bovine viral diarrhea virus (BVDV is a Pestivirus best known for causing a variety of disease syndromes in cattle, including gastrointestinal disease, reproductive insufficiency, immunosuppression, mucosal disease, and hemorrhagic syndrome. The virus can be spread by transiently infected individuals and by persistently infected animals that may be asymptomatic while shedding large amounts of virus throughout their lifetime. BVDV has been reported in over 40 domestic and free-ranging species, and persistent infection has been described in eight of those species: white-tailed deer, mule deer, eland, mousedeer, mountain goats, alpacas, sheep, and domestic swine. This paper reviews the various aspects of BVDV transmission, disease syndromes, diagnosis, control, and prevention, as well as examines BVDV infection in domestic and wild small ruminants and camelids including mountain goats (Oreamnos americanus.

  10. Effects of Multiple Routes of Cadmium Exposure on the Hibernation Success of the American Toad (Bufo americanus)

    Science.gov (United States)

    James, S.M.; Little, E.E.; Semlitsch, R.D.

    2004-01-01

    The effects of multiple routes of cadmium exposure on juvenile American toads (Bufo americanus) were evaluated using environmentally relevant concentrations. During or after exposure, toads were individually hibernated for 172 days at approximately 4??C. The following experiments were conducted: (1) dermal exposure (hibernation in soil contaminated with up to 120 ??g Cd/ g (dry weight)); (2) injection exposure (single injection with cadmium to achieve a maximum whole-body nominal concentration of 3 ??g Cd/g (wet weight) 12 days before hibernation in uncontaminated soil); and, (3) oral exposure (feeding with mealworms containing ???16 ??g Cd/g (dry weight) for 50 days before hibernation in uncontaminated soil)., We hypothesized that sublethal levels of cadmium would become lethal during hibernation because of combined chemical and cold stress. No prehibernation mortality occurred in the injection and oral exposure studies. There was a significant treatment effect on whole-body cadmium concentration in toads orally or dermally exposed and on percent of cadmium retention in toads orally exposed. There was also a trend of increased time-to-burrowing and more toads partially buried with greater cadmium concentration in the dermal study, which indicated avoidance. In all 3 experiments, no significant differences were found among cadmium treatments in hibernation survival, percent of mass loss, or locomotor performance. However, toads fed mealworms averaging 4.7 ??g Cd/g (dry weight) had only 56% survival compared with 100% survival for controls. Although our results suggest that environmentally relevant levels of cadmium do not pose a great risk to American toads, factors such as soil type or prey species may increase cadmium bioavailability, and other amphibian species may be more sensitive to cadmium than B. americanus.

  11. Phylogeographic Analyses of American Black Bears (Ursus americanus) Suggest Four Glacial Refugia and Complex Patterns of Postglacial Admixture.

    Science.gov (United States)

    Puckett, Emily E; Etter, Paul D; Johnson, Eric A; Eggert, Lori S

    2015-09-01

    Studies of species with continental distributions continue to identify intraspecific lineages despite continuous habitat. Lineages may form due to isolation by distance, adaptation, divergence across barriers, or genetic drift following range expansion. We investigated lineage diversification and admixture within American black bears (Ursus americanus) across their range using 22 k single nucleotide polymorphisms and mitochondrial DNA sequences. We identified three subcontinental nuclear clusters which we further divided into nine geographic regions: Alaskan (Alaska-East), eastern (Central Interior Highlands, Great Lakes, Northeast, Southeast), and western (Alaska-West, West, Pacific Coast, Southwest). We estimated that the western cluster diverged 67 ka, before eastern and Alaskan divergence 31 ka; these divergence dates contrasted with those from the mitochondrial genome where clades A and B diverged 1.07 Ma, and clades A-east and A-west diverged 169 ka. We combined estimates of divergence timing with hindcast species distribution models to infer glacial refugia for the species in Beringia, Pacific Northwest, Southwest, and Southeast. Our results show a complex arrangement of admixture due to expansion out of multiple refugia. The delineation of the genomic population clusters was inconsistent with the ranges for 16 previously described subspecies. Ranges for U. a. pugnax and U. a. cinnamomum were concordant with admixed clusters, calling into question how to order taxa below the species level. Additionally, our finding that U. a. floridanus has not diverged from U. a. americanus also suggests that morphology and genetics should be reanalyzed to assess taxonomic designations relevant to the conservation management of the species. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution. All rights reserved.For permissions please email: journals.permissions@oup.com.

  12. Crystallization and preliminary X-ray analysis of Na-SAA-2 from the human hookworm parasite Necator americanus

    International Nuclear Information System (INIS)

    Asojo, Oluwatoyin A.; Goud, Gaddam N.; Zhan, Bin; Ordonez, Katherine; Sedlacek, Meghan; Homma, Kohei; Deumic, Vehid; Gupta, Richi; Brelsford, Jill; Price, Merelyn K.; Ngamelue, Michelle N.; Hotez, Peter J.

    2010-01-01

    The purification, crystallization and preliminary X-ray diffraction analysis of a surface-associated antigen from the major human hookworm N. americanus is presented. Human hookworms are among the most pathogenic soil-transmitted helminths. These parasitic nematodes have co-evolved with the host and are able to maintain a high worm burden for decades without killing the human host. However, it is possible to develop vaccines against laboratory-challenge hookworm infections using either irradiated third-state infective larvae (L3) or enzymes from the adult parasites. In an effort to control hookworm infection globally, the Human Hookworm Vaccine Initiative, a product-development partnership with the Sabin Vaccine Institute to develop new control tools including vaccines, has identified a battery of protein antigens, including surface-associated antigens (SAAs) from L3. SAA proteins are characterized by a 13 kDa conserved domain of unknown function. SAA proteins are found on the surface of infective L3 stages (and some adult stages) of different nematode parasites, suggesting that they may play important roles in these organisms. The atomic structures and function of SAA proteins remain undetermined and in an effort to remedy this situation recombinant Na-SAA-2 from the most prevalent human hookworm parasite Necator americanus has been expressed, purified and crystallized. Useful X-ray data have been collected to 2.3 Å resolution from a crystal that belonged to the monoclinic space group C2 with unit-cell parameters a = 73.88, b = 35.58, c = 42.75 Å, β = 116.1°

  13. Assays for Detection and Identification of the Causative Agent of Mange in Free-Ranging Black Bears ( Ursus americanus).

    Science.gov (United States)

    Peltier, Sarah K; Brown, Justin D; Ternent, Mark A; Fenton, Heather; Niedringhaus, Kevin D; Yabsley, Michael J

    2018-03-02

    Three mite species ( Demodex ursi, Ursicoptes americanus, and Sarcoptes scabiei) have been associated with mange in black bears ( Ursus americanus). Since the early 1990s, the number and geographic distribution of mange cases in black bears in Pennsylvania has increased; however, the causative mites have yet to be completely defined. We evaluated several diagnostic approaches for detection and identification of mites in 72 black bears with severe lesions consistent with mange. Sarcoptes scabiei was morphologically identified in skin scrapes from 66 of the bears; no mites were identified in the remaining six. Histopathologic lesions consistent with sarcoptic mange were observed in 39 of 40 bear skin samples examined, and intralesional mites were observed in samples from 38 of these bears. Samples were collected from a subset of the 72 bears for PCR testing targeting both the internal transcribed spacer (ITS)-2 region and cytochrome c oxidase I ( cox1) gene including 69 skin scrapes ( ITS-2 only), 56 skin biopsies ( ITS-2 and cox1), and 36 fecal samples ( ITS-2 and cox1). Skin scrapes were a more sensitive sample for PCR detection than either skin biopsies or fecal samples, and the ITS-2 primers proved more sensitive than cox1. Using a commercial indirect enzyme-linked immunosorbent assay, antibodies to S. scabiei were detected in 45/49 (92%) black bears with confirmed mange and 0/62 (0%) cubs with no gross lesions suggestive of mange and which were born to seronegative sows. Sarcoptes scabiei was the predominant mite associated with mange in black bears in Pennsylvania. Diagnostically, cytologic examination of skin scrapes was the most effective approach for diagnosing active mite infestations in black bears. The evaluated serologic assay accurately detected antibodies to S. scabiei in most bears with confirmed S. scabiei infestations. Additional research is needed to determine the usefulness of this approach for larger scale surveys and for asymptomatic bears.

  14. Hookworm infection and anemia in adult women in rural Chiapas, Mexico Anemia e infección por Necator americanus en mujeres en Chiapas, México

    Directory of Open Access Journals (Sweden)

    Paula E. Brentlinger

    2003-04-01

    Full Text Available OBJECTIVE: To describe associations between anemia and hookworm (Necator americanus infection in hospitalized women in rural Chiapas, Mexico. MATERIAL AND METHODS: We retrospectively reviewed the hospital records of 68 anemic women (defined as having a hemoglobin level OBJETIVO: Describir la asociación entre anemia severa e infección con Necator americanus en una población de mujeres hospitalizadas en el estado de Chiapas, México. MATERIAL Y MÉTODOS: En el registro de ingresos del año 1999 de un hospital rural en Altamirano, Chiapas, se identificaron a las pacientes con diagnósticos de egreso de anemia (definida como hemoglobina<10mg/dl y/o parasitosis intestinal. También se revisó el registro de transfusiones para identificar a las mujeres mayores de 14 años de edad que recibieron sangre. La revisión de expedientes y el análisis de datos se llevó a cabo en el año 2000. Las comparaciones de las características de las pacientes se hicieron con la prueba t de Student (para variables continuas y la prueba ji2 (para variables categóricas. La significancia estadística se estableció con un valor de p< 0.01. RESULTADOS: En las mujeres en quienes se realizó examen coproscópico, 50% tuvieron N. americanus. La presencia de N. americanus no excluyó la presencia de otro factor de riesgo para anemia, por ejemplo embarazo o hemorragia. Los niveles de hemoglobina de las mujeres infectadas con N. americanus fueron significativamente más bajos (promedio 4.1 g/dl que los de las demás mujeres anémicas (promedio 7.0 gm/dl, y la prevalencia de N. americanus en mujeres anémicas fue más alta (50.0% que en la población atendida por el hospital (1.9%. CONCLUSIONES: Aunque la prevalencia de infección con N. americanus no se considera alta en la población general mexicana, fue importante en las mujeres anémicas que se sometieron a coproscopía en nuestro estudio. Las mujeres anémicas ameritan coproscopía donde existe N. americanus, y pueden

  15. Cell-stage-specific enhancement by caffeine of the frequency of chromatid aberrations induced by X-rays in neutral ganglia of Drosophila melanogaster

    International Nuclear Information System (INIS)

    De Marco, A.; Polani, S.

    1981-01-01

    Caffeine (10 -2 M) induced a high level of chromatid aberrations in neural ganglia of third-instar larvae of Drosophila melanogaster only when it was added to cells in late G 2 and mitotic prophase. No aberrations were observed after treatment in late S-middle G 2 or C-mitosis. We observed that, in these stages, caffeine strongly increased X-ray-induced damage (500 R). This potentiation was quantitatively similar. But it involved all types of aberration after treatment in C-mitosis, and essentially isochromatid deletions and chromatid exhanges after treatment in S-G 2 . Some hypotheses are put forth to explain the possible mechanism of action of caffeine in the potentiation of X-ray-induced damage. (orig.)

  16. Transverse energy and neutral pion spectra obtained from 16O- and 32S-induced reactions at 200 GeV/nucleon

    International Nuclear Information System (INIS)

    Plasil, F.; Albrecht, R.; Awes, T.C.

    1989-01-01

    The main goal of the CERN heavy-ion experiments is the search for an indication that the predicted state of deconfined quarks and gluons, the quark-gluon plasma (QGP), has been produced. The most promising indication that this may, in fact, be the case comes from the NA38 dimuon measurements, which are focused on the question of J//psi/ suppression. This effect was predicted to be one of the signatures of QGP formation before any measurements were made, and it is the subject of the two other talks at this conference that deal with nucleus-nucleus reactions at ultrarelativistic energies. In this presentation we consider the general (global) features of heavy-ion reactions at CERN energies, and we examine the degree to which they differ from mere superpositions of nucleon-nucleon collisions. We discuss the present status of our data analysis and our main conclusions from the first round of CERN experiments with emphasis on transverse energy measurements, on attained energy densities, and on the spectra of produced neutral pions. Because of time limitations we will not discuss our measurements of distributions of charged particles and the analysis of these distributions in terms of fluctuations nor the results that we have obtained with the Plastic Ball on the behavior of target spectator matter. 20 refs., 5 figs

  17. Occurrence of Larvae and Juveniles of Eucinostomus argenteus, Eucinostomus gula, Menticirrhus americanus, Menticirrhus littoralis, Umbrina coroides and Micropogonias furnieri at Pontal do Sul beach, Paraná

    Directory of Open Access Journals (Sweden)

    Rodrigo Santiago Godefroid

    2001-12-01

    Full Text Available Despite its importance, most ichthyoplankton studies in the South-Southeastern coast of Brazil, have been accomplished on the continental shelf. Regarding the beach environment, recognized as a nursery, little is known about the ichthyoplankton. We analyzed 288 samples collected with a 18 by 2 m seine net, 1 mm mesh and a conical plankton net, with a mesh of 300 mum and a 60 cm mouth. Eucinostomus argenteus comprised 78 % of the larvae and juveniles caught in the samples. The occurrence of gerreids was strongly concentrated in the summer, while the Menticirrhus littoralis, Menticirrhus americanus and Umbrina coroides were present during all seasons. M.littoralis was most abundant during spring, while M. americanus and U. coroides dominated during winter. For all species, the largest captures occurred during low tide. Environmental preferences are indicated in the principal component analysis, with the larvae and juveniles of E. argenteus and E. gula positively correlated with smaller waves and smaller morphodynamism, whereas M. americanus, U. coroides and M. furnieri seem to prefer periods with lower temperatures and larger morphodynamism.Apesar da importância, a maioria dos estudos de ictioplâncton na costa sul-sudeste do Brasil, foram realizados sobre a plataforma continental. No que se refere ao ambiente praial, reconhecido como área de criação, pouco se sabe sobre o ictioplâncton. Foram analisadas 288 amostras coletadas com uma rede tipo picaré com 18 x 2 m e malha de 1mm, e rede de plancton cônica, com malha de 300 mim e boca de 60 cm. A espécie E. argenteus totalizou 78 % das larvas e juvenis capturados. A ocorrência dos gerreideos foi fortemente concentrada no verão, enquanto que Menticirrhus littoralis, Menticirrhus americanus e Umbrina coroides estiveram presentes em todas as estações do ano. M. littoralis foi mais abundante na primavera, enquanto que M. americanus e U. coroides dominaram no inverno. Em todas as esp

  18. A replicating modified vaccinia tiantan strain expressing an avian-derived influenza H5N1 hemagglutinin induce broadly neutralizing antibodies and cross-clade protective immunity in mice.

    Directory of Open Access Journals (Sweden)

    Haixia Xiao

    Full Text Available To combat the possibility of a zoonotic H5N1 pandemic in a timely fashion, it is necessary to develop a vaccine that would confer protection against homologous and heterologous human H5N1 influenza viruses. Using a replicating modified vaccinia virus Tian Tan strain (MVTT as a vaccine vector, we constructed MVTTHA-QH and MVTTHA-AH, which expresses the H5 gene of a goose-derived Qinghai strain A/Bar-headed Goose/Qinghai/1/2005 or human-derived Anhui Strain A/Anhui/1/2005. The immunogenicity profiles of both vaccine candidates were evaluated. Vaccination with MVTTHA-QH induced a significant level of neutralizing antibodies (Nabs against a homologous strain and a wide range of H5N1 pseudoviruses (clades 1, 2.1, 2.2, 2.3.2, and 2.3.4. Neutralization tests (NT and Haemagglutination inhibition (HI antibodies inhibit the live autologous virus as well as a homologous A/Xingjiang/1/2006 and a heterologous A/Vietnam/1194/2004, representing two human isolates from clade 2.2 and clade 1, respectively. Importantly, mice vaccinated with intranasal MVTTHA-QH were completely protected from challenge with lethal dosages of A/Bar-headed Goose/Qinghai/1/2005 and the A/Viet Nam/1194/2004, respectively, but not control mice that received a mock MVTTS vaccine. However, MVTTHA-AH induced much lower levels of NT against its autologous strain. Our results suggest that it is feasible to use the H5 gene from A/Bar-headed Goose/Qinghai/1/2005 to construct an effective vaccine, when using MVTT as a vector, to prevent infections against homologous and genetically divergent human H5N1 influenza viruses.

  19. Multimeric scaffolds displaying the HIV-1 envelope MPER induce MPER-specific antibodies and cross-neutralizing antibodies when co-immunized with gp160 DNA.

    Directory of Open Access Journals (Sweden)

    Shelly J Krebs

    Full Text Available Developing a vaccine that overcomes the diversity of HIV-1 is likely to require a strategy that directs antibody (Ab responses toward conserved regions of the viral Envelope (Env. However, the generation of neutralizing Abs (NAbs targeting these regions through vaccination has proven to be difficult. One conserved region of particular interest is the membrane proximal external region (MPER of Env located within the gp41 ectodomain. In order to direct the immune response to this region, the MPER and gp41 ectodomain were expressed separately as N-terminal fusions to the E2 protein of Geobacillus stearothermophilus. The E2 protein acts as a scaffold by self-assembling into 60-mer particles, displaying up to 60 copies of the fused target on the surface. Rabbits were immunized with E2 particles displaying MPER and/or the gp41 ectodomain in conjunction with DNA encoding full-length gp160. Only vaccines including E2 particles displaying MPER elicited MPER-specific Ab responses. NAbs were elicited after two immunizations that largely targeted the V3 loop. To overcome V3 immunodominance in the DNA component, E2 particles displaying MPER were used in conjunction with gp160 DNA lacking hypervariable regions V2, V3, or combined V1V2V3. All rabbits had HIV binding Ab responses and NAbs following the second vaccination. Using HIV-2/HIV-1 MPER chimeric viruses as targets, NAbs were detected in 12/16 rabbits after three immunizations. Low levels of NAbs specific for Tier 1 and 2 viruses were observed in all groups. This study provides evidence that co-immunizing E2 particles displaying MPER and gp160 DNA can focus Ab responses toward conserved regions of Env.

  20. Neutral beam development plan

    International Nuclear Information System (INIS)

    Staten, H.S.

    1980-08-01

    The national plan is presented for developing advanced injection systems for use on upgrades of existing experiments, and use on future facilities such as ETF, to be built in the late 1980's or early 90's where power production from magnetic fusion will move closer to a reality. Not only must higher power and longer pulse length systems be developed , but they must operate reliably; they must be a tool for the experimenter, not the experiment itself. Neutral beam systems handle large amounts of energy and as such, they often are as complicated as the plasma physics experiment itself. This presents a significant challenge to the neutral beam developer

  1. Neutral beam program

    International Nuclear Information System (INIS)

    Anon.

    1979-01-01

    The structure of the beam injection program for the Doublet-3 device is discussed. The design considerations for the beam line and design parameters for the Doublet-3 ion souce are given. Major components of the neutral beam injector system are discussed in detail. These include the neutralizer, magnetic shielding, reflecting magnets, vacuum system, calorimeter and beam dumps, and drift duct. The planned location of the two-injector system for Doublet-3 is illustrated and site preparation is considered. The status of beamline units 1 and 2 and the future program schedule are discussed

  2. Pichia pastoris-expressed dengue 2 envelope forms virus-like particles without pre-membrane protein and induces high titer neutralizing antibodies.

    Directory of Open Access Journals (Sweden)

    Shailendra Mani

    Full Text Available Dengue is a mosquito-borne viral disease with a global prevalence. It is caused by four closely-related dengue viruses (DENVs 1-4. A dengue vaccine that can protect against all four viruses is an unmet public health need. Live attenuated vaccine development efforts have encountered unexpected interactions between the vaccine viruses, raising safety concerns. This has emphasized the need to explore non-replicating dengue vaccine options. Virus-like particles (VLPs which can elicit robust immunity in the absence of infection offer potential promise for the development of non-replicating dengue vaccine alternatives. We have used the methylotrophic yeast Pichia pastoris to develop DENV envelope (E protein-based VLPs. We designed a synthetic codon-optimized gene, encoding the N-terminal 395 amino acid residues of the DENV-2 E protein. It also included 5' pre-membrane-derived signal peptide-encoding sequences to ensure proper translational processing, and 3' 6× His tag-encoding sequences to facilitate purification of the expressed protein. This gene was integrated into the genome of P. pastoris host and expressed under the alcohol oxidase 1 promoter by methanol induction. Recombinant DENV-2 protein, which was present in the insoluble membrane fraction, was extracted and purified using Ni(2+-affinity chromatography under denaturing conditions. Amino terminal sequencing and detection of glycosylation indicated that DENV-2 E had undergone proper post-translational processing. Electron microscopy revealed the presence of discrete VLPs in the purified protein preparation after dialysis. The E protein present in these VLPs was recognized by two different conformation-sensitive monoclonal antibodies. Low doses of DENV-2 E VLPs formulated in alum were immunogenic in inbred and outbred mice eliciting virus neutralizing titers >1,1200 in flow cytometry based assays and protected AG129 mice against lethal challenge (p<0.05. The formation of immunogenic DENV-2 E

  3. Evaluation of black bear (Ursus americanus) diet and consequences in its conservation in Sierra de Picachos, Nuevo León, Mexico

    OpenAIRE

    Juárez-Casillas, Luis Antonio; Varas, Cora

    2013-01-01

    Black bears (Ursus americanus) are considered endangered in Mexico. In northern Mexico, bears are considered responsible for preying on livestock, damaging private property, and crops; therefore they are killed to protect locals' livelihoods. There is a need to understand bears' ecological requirements in order to create conservation plans that include human-bear conflict resolution and that reduce the hunting of this endangered species. We studied the diet of black bears in the Sierra de Pic...

  4. Development and evaluation of a Loop Mediated Isothermal Amplification (LAMP) technique for the detection of hookworm (Necator americanus) infection in fecal samples

    OpenAIRE

    Mugambi, Robert Muriuki; Agola, Eric L.; Mwangi, Ibrahim N.; Kinyua, Johnson; Shiraho, Esther Andia; Mkoji, Gerald M.

    2015-01-01

    Background Hookworm infection is a major concern in sub-Saharan Africa, particularly in children and pregnant women. Necator americanus and Ancylostoma duodenale are responsible for this condition. Hookworm disease is one of the Neglected tropical diseases (NTDs) that are targeted for elimination through global mass chemotherapy. To support this there is a need for reliable diagnostic tools. The conventional diagnostic test, Kato-Katz that is based on microscopic detection of parasite ova in ...

  5. 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...

  6. 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.)

  7. ITER neutral beam system

    International Nuclear Information System (INIS)

    Mondino, P.L.; Di Pietro, E.; Bayetti, P.

    1999-01-01

    The Neutral Beam (NB) system for the International Thermonuclear Experimental Reactor (ITER) has reached a high degree of integration with the tokamak and with the rest of the plant. Operational requirements and maintainability have been considered in the design. The paper considers the integration with the tokamak, discusses design improvements which appear necessary and finally notes R and D progress in key areas. (author)

  8. Citrus huanglongbing: validation of Real-Time PCR (qPCR for the detection of Candidatus Liberibacter asiaticus and Candidatus Liberibacter americanus in Colombia

    Directory of Open Access Journals (Sweden)

    Jorge Evelio Ángel

    2014-12-01

    Full Text Available Citrus huanglongbing (HLB is the most destructive citrus disease. Two of the three known HLB-associated Candidatus Liberibacter species were recently found to be present in the Americas. In this study, eggs, nymphs and adults of Diaphorina citri Kuwayama (Hemiptera: Liviidae and suspect citrus plant materials were collected in 25 municipalities in the departments of Cundinamarca, Santander, Valle del Cauca, Meta and Quindio (Colombia. The detection sensitivity, specificity and assay performance of the 16S rDNA-based real-time PCR (qPCR were validated for the field survey of the disease in Colombia. The validation confirmed the reliability and robustness of the real-time PCR method for the detection of HLB bacteria in host citrus plant tissues and the vector D. citri. The diagnosis was performed for Candidatus Liberibacter asiaticus (Ca. L. asiaticus and for Candidatus Liberibacter americanus (Ca. L. americanus on 168 citrus plant material samples and 239 insect samples. Neither Ca. L. asiaticus nor Ca. L. americanus were detected in the host plants or insects vector, confirming the absence of the disease in the citrus-producing areas of Colombia.

  9. A tetravalent virus-like particle vaccine designed to display domain III of dengue envelope proteins induces multi-serotype neutralizing antibodies in mice and macaques which confer protection against antibody dependent enhancement in AG129 mice.

    Directory of Open Access Journals (Sweden)

    Viswanathan Ramasamy

    2018-01-01

    Full Text Available Dengue is one of the fastest spreading vector-borne diseases, caused by four antigenically distinct dengue viruses (DENVs. Antibodies against DENVs are responsible for both protection as well as pathogenesis. A vaccine that is safe for and efficacious in all people irrespective of their age and domicile is still an unmet need. It is becoming increasingly apparent that vaccine design must eliminate epitopes implicated in the induction of infection-enhancing antibodies.We report a Pichia pastoris-expressed dengue immunogen, DSV4, based on DENV envelope protein domain III (EDIII, which contains well-characterized serotype-specific and cross-reactive epitopes. In natural infection, <10% of the total neutralizing antibody response is EDIII-directed. Yet, this is a functionally relevant domain which interacts with the host cell surface receptor. DSV4 was designed by in-frame fusion of EDIII of all four DENV serotypes and hepatitis B surface (S antigen and co-expressed with unfused S antigen to form mosaic virus-like particles (VLPs. These VLPs displayed EDIIIs of all four DENV serotypes based on probing with a battery of serotype-specific anti-EDIII monoclonal antibodies. The DSV4 VLPs were highly immunogenic, inducing potent and durable neutralizing antibodies against all four DENV serotypes encompassing multiple genotypes, in mice and macaques. DSV4-induced murine antibodies suppressed viremia in AG129 mice and conferred protection against lethal DENV-4 virus challenge. Further, neither murine nor macaque anti-DSV4 antibodies promoted mortality or inflammatory cytokine production when passively transferred and tested in an in vivo dengue disease enhancement model of AG129 mice.Directing the immune response to a non-immunodominant but functionally relevant serotype-specific dengue epitope of the four DENV serotypes, displayed on a VLP platform, can help minimize the risk of inducing disease-enhancing antibodies while eliciting effective tetravalent

  10. A novel trivalent HPV 16/18/58 vaccine with anti-HPV 16 and 18 neutralizing antibody responses comparable to those induced by the Gardasil quadrivalent vaccine in rhesus macaque model

    Directory of Open Access Journals (Sweden)

    Fei Yin

    2017-06-01

    Full Text Available Persistent infection with human papillomavirus (HPV is a key factor in the development of precancerous lesions and invasive cervical cancer. Prophylactic vaccines to immunize against HPV are an effective approach to reducing HPV related disease burden. In this study, we investigated the immunogenicity and dosage effect of a trivalent HPV 16/18/58 vaccine (3vHPV produced in Escherichia coli (E.coli, with Gardasil quadrivalent vaccine (4vHPV, Merck & Co. as a positive control. Sera collected from rhesus macaques vaccinated with three dosage formulations of 3vHPV (termed low-, mid-, and high-dosage formulations, respectively, and the 4vHPV vaccine were analyzed by both Pseudovirus-Based Neutralization Assay (PBNA and Enzyme-Linked Immunosorbent Assay (ELISA. Strong immune responses against HPV 16/18/58 were successfully elicited, and dosage-dependence was observed, with likely occurrence of immune interference between different L1-VLP antigens. HPV 16/18 specific neutralizing antibody (nAb and total immunoglobulin G (IgG antibody responses in rhesus macaques receiving 3vHPV at the three dosages tested were generally non-inferior to those observed in rhesus macaques receiving 4vHPV throughout the study period. Particularly, HPV 18 nAb titers induced by the mid-dosage formulation that contained the same amounts of HPV 16/18 L1-VLPs as Gardasil 4vHPV were between 7.3 to 12.7-fold higher compared to the positive control arm from weeks 24–64. The durability of antibody responses specific to HPV 16/18 elicited by 3vHPV vaccines was also shown to be non-inferior to that associated with Gardasil 4vHPV. Keywords: Human papillomavirus, HPV 16/18/58, GMTs, Trivalent, Immunogenicity

  11. Whole-Chain Tick Saliva Proteins Presented on Hepatitis B Virus Capsid-Like Particles Induce High-Titered Antibodies with Neutralizing Potential.

    Directory of Open Access Journals (Sweden)

    Philipp Kolb

    Full Text Available Ticks are vectors for various, including pathogenic, microbes. Tick saliva contains multiple anti-host defense factors that enable ticks their bloodmeals yet also facilitate microbe transmission. Lyme disease-causing borreliae profit specifically from the broadly conserved tick histamine release factor (tHRF, and from cysteine-rich glycoproteins represented by Salp15 from Ixodes scapularis and Iric-1 from Ixodes ricinus ticks which they recruit to their outer surface protein C (OspC. Hence these tick proteins are attractive targets for anti-tick vaccines that simultaneously impair borrelia transmission. Main obstacles are the tick proteins´ immunosuppressive activities, and for Salp15 orthologs, the lack of efficient recombinant expression systems. Here, we exploited the immune-enhancing properties of hepatitis B virus core protein (HBc derived capsid-like particles (CLPs to generate, in E. coli, nanoparticulate vaccines presenting tHRF and, as surrogates for the barely soluble wild-type proteins, cysteine-free Salp15 and Iric-1 variants. The latter CLPs were exclusively accessible in the less sterically constrained SplitCore system. Mice immunized with tHRF CLPs mounted a strong anti-tHRF antibody response. CLPs presenting cysteine-free Salp15 and Iric-1 induced antibodies to wild-type, including glycosylated, Salp15 and Iric-1. The broadly distributed epitopes included the OspC interaction sites. In vitro, the anti-Salp15 antibodies interfered with OspC binding and enhanced human complement-mediated killing of Salp15 decorated borreliae. A mixture of all three CLPs induced high titered antibodies against all three targets, suggesting the feasibility of combination vaccines. These data warrant in vivo validation of the new candidate vaccines´ protective potential against tick infestation and Borrelia transmission.

  12. Whole-Chain Tick Saliva Proteins Presented on Hepatitis B Virus Capsid-Like Particles Induce High-Titered Antibodies with Neutralizing Potential

    Science.gov (United States)

    Kolb, Philipp; Wallich, Reinhard; Nassal, Michael

    2015-01-01

    Ticks are vectors for various, including pathogenic, microbes. Tick saliva contains multiple anti-host defense factors that enable ticks their bloodmeals yet also facilitate microbe transmission. Lyme disease-causing borreliae profit specifically from the broadly conserved tick histamine release factor (tHRF), and from cysteine-rich glycoproteins represented by Salp15 from Ixodes scapularis and Iric-1 from Ixodes ricinus ticks which they recruit to their outer surface protein C (OspC). Hence these tick proteins are attractive targets for anti-tick vaccines that simultaneously impair borrelia transmission. Main obstacles are the tick proteins´ immunosuppressive activities, and for Salp15 orthologs, the lack of efficient recombinant expression systems. Here, we exploited the immune-enhancing properties of hepatitis B virus core protein (HBc) derived capsid-like particles (CLPs) to generate, in E. coli, nanoparticulate vaccines presenting tHRF and, as surrogates for the barely soluble wild-type proteins, cysteine-free Salp15 and Iric-1 variants. The latter CLPs were exclusively accessible in the less sterically constrained SplitCore system. Mice immunized with tHRF CLPs mounted a strong anti-tHRF antibody response. CLPs presenting cysteine-free Salp15 and Iric-1 induced antibodies to wild-type, including glycosylated, Salp15 and Iric-1. The broadly distributed epitopes included the OspC interaction sites. In vitro, the anti-Salp15 antibodies interfered with OspC binding and enhanced human complement-mediated killing of Salp15 decorated borreliae. A mixture of all three CLPs induced high titered antibodies against all three targets, suggesting the feasibility of combination vaccines. These data warrant in vivo validation of the new candidate vaccines´ protective potential against tick infestation and Borrelia transmission. PMID:26352137

  13. 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.

  14. 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.

  15. Neutral beams for mirrors

    International Nuclear Information System (INIS)

    Fink, J.H.

    1983-01-01

    An important demonstration of negative ion technology is proposed for FY92 in the MFTF-α+T, an upgrade of the Mirror Fusion Test Facility at the Lawrence Livermore National Laboratory. This facility calls for 200-keV negative ions to form neutral beams that generate sloshing ions in the reactor end plugs. Three different beam lines are considered for this application. Their advantages and disadvantages are discussed

  16. 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.

  17. Climate Neutral Campus Key Terms and Definitions | Climate Neutral Research

    Science.gov (United States)

    Campuses | NREL Neutral Campus Key Terms and Definitions Climate Neutral Campus Key Terms and Definitions The term climate neutral evolved along with net zero and a number of other "green" and accuracy in these areas lets research campuses know exactly how close they are to climate

  18. Influence of natural inshore and offshore thermal regimes on egg development and time of hatch in American lobsters, Homarus americanus.

    Science.gov (United States)

    Goldstein, Jason S; Watson, Winsor H

    2015-02-01

    Some egg-bearing (ovigerous) American lobsters (Homarus americanus) make seasonal inshore-to-offshore movements, subjecting their eggs to different thermal regimes than those of eggs carried by lobsters that do not make these movements. Our goal was to determine if differences in thermal regimes influence the rate of egg development and the subsequent time of hatch. We subjected ovigerous lobsters to typical inshore or offshore water temperatures from September to August in the laboratory (n=8 inshore and 8 offshore, each year) and in the field (n=8 each, inshore and offshore), over 2 successive years. Although the rate of egg development did not differ significantly between treatments in the fall (P∼0.570), eggs exposed to inshore thermal regimes developed faster in the spring (Plobsters exposed to offshore thermal regimes accumulated more GDD in the winter than did eggs carried by inshore lobsters, while eggs exposed to inshore temperatures acquired them more rapidly in the spring. Results suggest that seasonal movements of ovigerous lobsters influence the time and location of hatching, and thus the transport and recruitment of larvae to coastal and offshore locations. © 2015 Marine Biological Laboratory.

  19. Ranking harbours in the maritime provinces of Canada for potential to contaminate American lobster (Homarus americanus) with polycyclic aromatic hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    Prouse, N.J.

    1994-01-01

    Polycyclic aromatic hydrocarbons (PAHs) comprise a suite of contaminants that enter the marine environment through a variety of natural and anthropogenic sources. PAHs, including carcinogenic compounds, bioaccumulate in the tissues of exposed American lobsters (Homarus americanus). High PAH concentrations in lobster tissues necessitated the closure of the lobster fishery in the South Arm of Sydney Harbour, Nova Scotia, in 1982. A study was conducted to assess harbors in Nova Scotia, New Brunswick, and Prince Edward Island to determine if there might be a reason for concern about PAH contamination of lobsters. Adjacent commercial and industrial activity, harbor uses, the surrounding population, and PAH point sources were evaluated for each harbor selected for study. Areas of lobster fishing and the number of permanent lobster holding facilities within each harbor were also determined. Harbors were then ranked according to their potential for PAH contamination. Point sources for PAHs within these harbors included petroleum and coal products plants, oil refineries, chemical plants, coal-fired generating stations, and fuel combustion in land vehicles and ships. After Sydney, the harbors with the highest potential for PAH contamination were determined to be Halifax, Saint John, Pictou, and Port Hawkesbury Ship Harbour. 60 refs., 15 figs., 7 tabs.

  20. Identification and phylogenetic analysis of Dirofilaria ursi (Nematoda: Filarioidea) from Wisconsin black bears (Ursus americanus) and its Wolbachia endosymbiont.

    Science.gov (United States)

    Michalski, Michelle L; Bain, Odile; Fischer, Kerstin; Fischer, Peter U; Kumar, Sanjay; Foster, Jeremy M

    2010-04-01

    Dirofilaria ursi is a filarial nematode of American black bears (Ursus americanus Pallas, 1780) that is vectored by black flies (Simuliidae) in many parts of the United States. In northwestern Wisconsin, the prevalence of microfilaremic bears during the fall hunting season was 21% (n = 47). Unsheathed blood microfilariae from Wisconsin bears possess characters consistent with the original description of D. ursi, as do adult worms observed histologically and grossly. Immunohistochemistry was used to identify the Wolbachia endosymbiont in the hypodermis and lateral cords of an adult female D. ursi. Amplification of wsp, gatB, coxA, fbpA, and ftsZ bacterial sequences from parasite DNA confirmed the presence of Wolbachia, and molecular phylogenetic analysis of the Wolbachia ftsZ gene groups the endosymbiont with Wolbachia from D. immitis and D. repens. Phylogenetic analysis of D. ursi 5s rDNA sequence confirms the morphological observations grouping this parasite as a member of Dirofilaria, and within the Dirofilaria - Onchocerca clade of filarial nematodes. This is the first report of Wolbachia characterization and molecular phylogeny information for D. ursi.

  1. Ticks and tick-borne pathogens and putative symbionts of black bears (Ursus americanus floridanus) from Georgia and Florida.

    Science.gov (United States)

    Yabsley, Michael J; Nims, Todd N; Savage, Mason Y; Durden, Lance A

    2009-10-01

    Ticks were collected from 38 black bears (Ursus americanus floridanus) from northwestern Florida (n = 18) from 2003 to 2005 and southern Georgia (n = 20) in 2006. Five species (Amblyomma americanum, A. maculatum, Dermacentor variabilis, Ixodes scapularis, and I. affinis) were collected from Florida bears, and 4 species (A. americanum, A. maculatum, D. variabilis, I. scapularis) were collected from bears in Georgia. Ixodes scapularis was the most frequently collected tick, followed by D. variabilis, A. americanum, A. maculatum, and I. affinis. The collection of I. affinis from a Florida bear represents a new host record. A subset of ticks was screened for pathogens and putative symbionts by polymerase chain reaction (PCR). The zoonotic tick-borne pathogens Ehrlichia chaffeensis and Rickettsia parkeri were detected in 1 of 23 (4.3%) A. americanum and 1 of 12 (8.3%) A. maculatum, respectively. The putative zoonotic pathogen "Rickettsia amblyommii" was detected in 4 (17.4%) A. americanum and 1 (8.3%) A. maculatum. Other putative symbiotic rickettsiae detected included R. bellii and R. montanensis in D. variabilis, a Rickettsia cooleyi-like sp. and Rickettsia sp. Is-1 in I. scapularis, and Rickettsia TR39-like sp. in I. scapularis and A. americanum. All ticks were PCR-negative for Anaplasma phagocytophilum, Panola Mountain Ehrlichia sp., E. ewingii, Francisella tularensis, and Borrelia spp.

  2. The effects of hibernation and captivity on glucose metabolism and thyroid hormones in American black bear (Ursus americanus).

    Science.gov (United States)

    McCain, Stephanie; Ramsay, Ed; Kirk, Claudia

    2013-06-01

    American black bears (Ursus americanus) have been shown to become transiently insulin resistant and hypothyroid during winter, but no studies have investigated these changes in long-term captive bears or in bears which remain awake year-round. Wild, captive hibernating, and captive nonhibernating bears were evaluated at times corresponding to three of their major physiologic stages: fall (hyperphagic stage), winter (hibernation stage), and summer (normal activity stage). Combined insulin and glucose tolerance tests and thyroid hormone profiles were performed on all bears during each stage. All three groups of bears had evidence of insulin resistance during the winter, as compared to the summer or fall, based on glucose tolerance curves. Analysis of thyroid hormone concentration varied and distinct patterns or similarities were not apparent. While obesity in captive American black bears is multifactorial, the finding that, regardless of their ability to hibernate, captive bears retain similar physiology to their wild counterparts indicates that captive bears' complex physiologic changes need to be addressed in their management.

  3. A new PCR-based method shows that blue crabs (Callinectes sapidus (Rathbun)) consume winter flounder (Pseudopleuronectes americanus (Walbaum)).

    Science.gov (United States)

    Collier, Jackie L; Fitzgerald, Sean P; Hice, Lyndie A; Frisk, Michael G; McElroy, Anne E

    2014-01-01

    Winter flounder (Pseudopleuronectes americanus) once supported robust commercial and recreational fisheries in the New York (USA) region, but since the 1990s populations have been in decline. Available data show that settlement of young-of-the-year winter flounder has not declined as sharply as adult abundance, suggesting that juveniles are experiencing higher mortality following settlement. The recent increase of blue crab (Callinectes sapidus) abundance in the New York region raises the possibility that new sources of predation may be contributing to juvenile winter flounder mortality. To investigate this possibility we developed and validated a method to specifically detect winter flounder mitochondrial control region DNA sequences in the gut contents of blue crabs. A survey of 55 crabs collected from Shinnecock Bay (along the south shore of Long Island, New York) in July, August, and September of 2011 showed that 12 of 42 blue crabs (28.6%) from which PCR-amplifiable DNA was recovered had consumed winter flounder in the wild, empirically supporting the trophic link between these species that has been widely speculated to exist. This technique overcomes difficulties with visual identification of the often unrecognizable gut contents of decapod crustaceans, and modifications of this approach offer valuable tools to more broadly address their feeding habits on a wide variety of species.

  4. First report of piscine nodavirus infecting wild winter flounder Pleuronectes americanus in Passamaquoddy Bay, New Brunswick, Canada.

    Science.gov (United States)

    Barke, Duane E; MacKinnon, Ann-Margaret; Boston, Linda; Burt, Michael D B; Cone, David K; Speare, David J; Griffiths, Steve; Cook, Marcia; Ritchie, Rachael; Olivier, Gilles

    2002-05-10

    Piscine nodaviruses (Betanodaviridae) are frequently reported from a variety of cultured and wild finfishes. These non-enveloped, single-stranded RNA virions cause viral encephalopathy and retinopathy (VER), also known as viral nervous necrosis (VNN) or fish encephalitis. Recently, nodavirus infections have posed serious problems for larval and juvenile cultured halibut Hippoglossus hippoglossus in Norway and Scotland. To date, no such viruses have been described from any cultured or wild pleuronectid in Atlantic Canada. Obviously, there exists a need to survey wild populations of pleuronectids to assess the risk of potential transfer of nodavirus from wild to caged fishes. This paper presents the results of monthly surveys (April 2000 to March 2001) of viruses from wild winter flounder Pleuronectes americanus collected from Passamaquoddy Bay, New Brunswick, Canada. Tissue samples from wild flounder were screened initially on commercial cell lines (EPC, SSN-1, SHK and CHSE-214) for any evidence of cytopathic effect (CPE). After confirmation of CPE, nodavirus identification was achieved using reverse transcription polymerase chain reaction (RT-PCR) analysis. We detected nodavirus from only 1 out of 440 flounder (0.23%) examined. This is the first report of piscine nodavirus isolated from wild winter flounder in Atlantic Canada, and although this prevalence may seem low, we discuss the implications of this finding for Canada's emerging halibut aquaculture industry.

  5. First evidence for slave rebellion: enslaved ant workers systematically kill the brood of their social parasite protomognathus americanus.

    Science.gov (United States)

    Achenbach, Alexandra; Foitzik, Susanne

    2009-04-01

    During the process of coevolution, social parasites have evolved sophisticated strategies to exploit the brood care behavior of their social hosts. Slave-making ant queens invade host colonies and kill or eject all adult host ants. Host workers, which eclose from the remaining brood, are tricked into caring for the parasite brood. Due to their high prevalence and frequent raids, following which stolen host broods are similarly enslaved, slave-making ants exert substantial selection upon their hosts, leading to the evolution of antiparasite adaptations. However, all host defenses shown to date are active before host workers are parasitized, whereas selection was thought to be unable to act on traits of already enslaved hosts. Yet, here we demonstrate the rebellion of enslaved Temnothorax workers, which kill two-thirds of the female pupae of the slave-making ant Protomognathus americanus. Thereby, slaves decrease the long-term parasite impact on surrounding related host colonies. This novel antiparasite strategy of enslaved workers constitutes a new level in the coevolutionary battle after host colony defense has failed. Our discovery is analogous to recent findings in hosts of avian brood parasites where perfect mimicry of parasite eggs leads to the evolution of chick recognition as a second line of defense.

  6. A truncated receptor-binding domain of MERS-CoV spike protein potently inhibits MERS-CoV infection and induces strong neutralizing antibody responses: implication for developing therapeutics and vaccines.

    Directory of Open Access Journals (Sweden)

    Lanying Du

    Full Text Available An emerging respiratory infectious disease with high mortality, Middle East respiratory syndrome (MERS, is caused by a novel coronavirus (MERS-CoV. It was first reported in 2012 in Saudi Arabia and has now spread to eight countries. Development of effective therapeutics and vaccines is crucial to save lives and halt the spread of MERS-CoV. Here, we show that a recombinant protein containing a 212-amino acid fragment (residues 377-588 in the truncated receptor-binding domain (RBD: residues 367-606 of MERS-CoV spike (S protein fused with human IgG Fc fragment (S377-588-Fc is highly expressed in the culture supernatant of transfected 293T cells. The purified S377-588-Fc protein efficiently binds to dipeptidyl peptidase 4 (DPP4, the receptor of MERS-CoV, and potently inhibited MERS-CoV infection, suggesting its potential to be further developed as a therapeutic modality for treating MERS-CoV infection and saving the patients' lives. The recombinant S377-588-Fc is able to induce in the vaccinated mice strong MERS-CoV S-specific antibodies, which blocks the binding of RBD to DPP4 receptor and effectively neutralizes MERS-CoV infection. These findings indicate that this truncated RBD protein shows promise for further development as an effective and safe vaccine for the prevention of MERS-CoV infection.

  7. Bremsstrahlung and neutral currents

    International Nuclear Information System (INIS)

    Ellis, R.G.; McKellar, B.H.J.

    1979-01-01

    The utility of the bremsstrahlung process in detecting parity violations from V-A weak neutral current interference is analysed in two ways. Firstly, bremsstrahlung from polarized lepton-nucleus scattering has an asymmetry with respect to the polarization of the incident leptons, and secondly, bremsstrahlung from unpolarized lepton nucleus scattering has a small circular polarization. The magnitude of each effect is calculated. The ratio of the parity violating contribution and the parity conserving contribution to the cross section is shown to be a misleading measure of the utility of these experiments. A parameter, the figure of merit, is introduced and used to discuss the feasibility of possible experiments

  8. Plasma neutralizer for H- beams

    International Nuclear Information System (INIS)

    Grossman, M.W.

    1977-01-01

    Neutralization of H - beams by a hydrogen plasma is discussed. Optimum target thickness and maximum neutralization efficiency as a function of the fraction of the hydrogen target gas ionized is calculated for different H - beam energies. Also, the variation of neutralization efficiency with respect to target thickness for different H - beam energies is computed. The dispersion of the neutralized beam by a magnetic field for different energies and different values of B . z is found. Finally, a type of plasma jet is proposed, which may be suitable for a compact H - neutralizer

  9. PROPAGACIÓN POR ESTACAS JUVENILES DEL BALSO BLANCO (Heliocarpus americanus L. Sin. H. popayanensis UTILIZANDO PROPAGADORES DE SUBIRRIGACIÓN PROPAGATION OF WHITE BALSUM (Heliocarpus americanus L. Sin. H. popayanensis CUTTINGS USING NONMIST PROPAGATORS

    Directory of Open Access Journals (Sweden)

    Carolina Vásquez Restrepo

    2006-12-01

    Full Text Available El mercado mundial de edulcorantes orgánicos es una oportunidad para la panela, producto básico de la canasta familiar que representa ingresos importantes para la población rural colombiana. El balso blanco (Heliocarpus americanus L. Sin. H. popayanensis Hook & Arn. es la especie más usada en procesos de clarificación de la panela en Antioquia y las zonas cañeras húmedas colombianas. Pero la extracción de la corteza de árboles obtenidos de la regeneración natural comienza a ser insostenible, por el daño causado a los individuos y la presión creciente a este recurso. La prohibición del uso de sustancias químicas en procesos de clarificación de panela ha aumentado la demanda de la corteza del balso blanco. En este trabajo se estimó el enraizamiento de estacas juveniles de balso blanco, por propagadores de subirrigación. Se realizaron dos experimentos, utilizando ácido anaftalenacético (ANA. En el primero se evaluó el efecto del transporte, cicatrizante y sustrato sobre el enraizamiento de las estacas de balso blanco. El mejor medio de transporte fue en cristales de hidrogel para mantener la humedad de las estacas, sin utilizar cicatrizante y sembrándolas en el sustrato tierra (55 % de enraizamiento. En el segundo se analizó la influencia de la intensidad lumínica y el área foliar en el porcentaje de enraizamiento de las estacas. El más alto enraizamiento se obtuvo con el tratamiento de doble sombra y un área foliar de 20 cm² (25 % de enraizamiento. Aunque los mejores resultados indican un relativo éxito en el uso de medios de enraizamiento, es una primera aproximación para propagar esta especie que necesita ser protegida.The world market of organic edulcorants is an opportunity for “panela”, a basic domestic consumption product that provides important income to rural population. White balsum (Heliocarpus americanus L. Sin. H. popayanensis Hook & Arn. is the most used species in the panela clarification processes in

  10. Neutral helium beam probe

    Science.gov (United States)

    Karim, Rezwanul

    1999-10-01

    This article discusses the development of a code where diagnostic neutral helium beam can be used as a probe. The code solves numerically the evolution of the population densities of helium atoms at their several different energy levels as the beam propagates through the plasma. The collisional radiative model has been utilized in this numerical calculation. The spatial dependence of the metastable states of neutral helium atom, as obtained in this numerical analysis, offers a possible diagnostic tool for tokamak plasma. The spatial evolution for several hypothetical plasma conditions was tested. Simulation routines were also run with the plasma parameters (density and temperature profiles) similar to a shot in the Princeton beta experiment modified (PBX-M) tokamak and a shot in Tokamak Fusion Test Reactor tokamak. A comparison between the simulation result and the experimentally obtained data (for each of these two shots) is presented. A good correlation in such comparisons for a number of such shots can establish the accurateness and usefulness of this probe. The result can possibly be extended for other plasma machines and for various plasma conditions in those machines.

  11. Sex, Diet, and the Social Environment: Factors Influencing Hair Cortisol Concentration in Free-Ranging Black Bears (Ursus americanus).

    Science.gov (United States)

    Lafferty, Diana J R; Laudenslager, Mark L; Mowat, Garth; Heard, Doug; Belant, Jerrold L

    2015-01-01

    Increasingly, measures of glucocorticoid levels (e.g., cortisol), key components of the neuroendocrine stress axis, are being used to measure past hypothalamic-pituitary-adrenal (HPA) activity to index psychological and physiological stress exhibited by wildlife for assessing individual and population-level well-being. However, many intrinsic and extrinsic factors affect HPA activity in animals. Using American black bears (Ursus americanus; n = 116) as an ecological model and hair cortisol concentration (HCC) as an integrative measure of past HPA activity, we evaluated the influence of diet, sex and the social environment on black bear HCC in a free-ranging population that spanned adjoining ecoregions with differing densities of potential conspecific and heterospecific competitors. HCC varied by sex, with female HCC ranging from 0.6 to 10.7 pg/mg (median = 4.5 ± 1.2 mean absolute deviation [MAD]) and male HCC ranging from 0.5 to 35.1 pg/mg (median = 6.2 ± 2.6 MAD). We also observed a three-way interaction among sex, δ14C and ecoregion, which may indicate that some differences in HCC between female and male black bears results from variability in the nutritional needs of larger-bodied males relative to smaller-bodied females, slight differences in food resources use between ecoregions as well as sex-based differences regarding the social environment. Once we understand what drives sex-specific differences in HCC, HCC may aid our understanding of the physiological responses by bears and other wildlife to diverse environmental challenges.

  12. Sex, Diet, and the Social Environment: Factors Influencing Hair Cortisol Concentration in Free-Ranging Black Bears (Ursus americanus)

    Science.gov (United States)

    Lafferty, Diana J. R.; Laudenslager, Mark L.; Mowat, Garth; Heard, Doug; Belant, Jerrold L.

    2015-01-01

    Increasingly, measures of glucocorticoid levels (e.g., cortisol), key components of the neuroendocrine stress axis, are being used to measure past hypothalamic-pituitary-adrenal (HPA) activity to index psychological and physiological stress exhibited by wildlife for assessing individual and population-level well-being. However, many intrinsic and extrinsic factors affect HPA activity in animals. Using American black bears (Ursus americanus; n = 116) as an ecological model and hair cortisol concentration (HCC) as an integrative measure of past HPA activity, we evaluated the influence of diet, sex and the social environment on black bear HCC in a free-ranging population that spanned adjoining ecoregions with differing densities of potential conspecific and heterospecific competitors. HCC varied by sex, with female HCC ranging from 0.6 to 10.7 pg/mg (median = 4.5 ± 1.2 mean absolute deviation [MAD]) and male HCC ranging from 0.5 to 35.1 pg/mg (median = 6.2 ± 2.6 MAD). We also observed a three-way interaction among sex, δ14C and ecoregion, which may indicate that some differences in HCC between female and male black bears results from variability in the nutritional needs of larger-bodied males relative to smaller-bodied females, slight differences in food resources use between ecoregions as well as sex-based differences regarding the social environment. Once we understand what drives sex-specific differences in HCC, HCC may aid our understanding of the physiological responses by bears and other wildlife to diverse environmental challenges. PMID:26529405

  13. Combined toxicity of free chlorine, chloramine, and temperature to stage 1 larvae of the American lobster Homarus americanus

    Energy Technology Data Exchange (ETDEWEB)

    Capuzzo, J M; Lawrence, S A; Davidson, J A

    1976-01-01

    The differential effects of free chlorine and chloramine on stage I larvae of the American lobster Homarus americanus have been investigated in continuous flow bioassay units. Applied chloramine was more toxic than corresponding concentrations of applied free chlorine to lobster larvae with estimated LC/sub 50/ values at 25/sup 0/ of 16.30 mg/l applied free chlorine and 2.02 mg/l applied chloramine. The synergistic effect of temperature on the toxicity of both free chlorine and chloramine has also been demonstrated. Exposure to applied free chlorine at 20/sup 0/ resulted in no significant mortality of test organisms, whereas exposure at 30/sup 0/ resulted in an estimated LC/sub 50/ value of 2.50 mg/l. Applied chloramine was considerably more toxic with an estimated LC/sub 50/ value at 20/sup 0/ of 4.08 mg/l and at 30/sup 0/ of 0.56 mg/l. The action of each toxicant appeared to be an alteration of standard metabolic activity as revealed by changes in respiration rates during and after exposure to applied free chlorine and chloramine. Initial respiratory stress was detected during exposure to 0.05 mg/l applied chloramine and 5.00 mg/l applied free chlorine. Reductions in respiration rates 48 h after exposure were observed with exposure to all concentrations tested, similar results being obtained following exposure to 0.05 mg/l applied chloramine and 0.10 mg/l applied free chlorine. These results are indicative of the need for information in addition to that obtained in standard bioassays for an adequate assessment of chlorine toxicity.

  14. Influence of drilling muds on the primary chemosensory neurons in walking legs of the lobster, Homarus americanus

    Energy Technology Data Exchange (ETDEWEB)

    Derby, C D; Atema, J

    1981-01-01

    The effects of whole drilling muds on the normal activity of walking leg chemosensory neurons of the lobster, Homarus americanus, were examined using extracellular neurophysiological recording techniques. Exposure of legs for 3-5 min to 10 mg/L drilling mud suspended in seawater altered responses to food odors of 29% of the chemoreceptors examined (data pooled for the two drilling muds tested); similar exposure to 100 mg/L drilling mud resulted in interference with 44% of all receptors studied. The effects of both of these concentrations are statistically significant, although they are not different from each other. Interference was usually manifested as a marked reduction in the number of action potentials in a response. In one preparation, the exposure to drilling mud caused a change in the temporal pattern of the spikes without affecting the total number of spikes. Other chemosensory neurons were excited by 10 mg/L drilling mud itself. However, not all chemoreceptors are inhibited by these drilling muds since responses to feeding stimuli were recorded from the legs of lobsters that had been exposed to drilling mud for 4-8 d before the neurophysiological experiments. Antennular and leg chemoreceptors are important in eliciting normal feeding behavior in lobsters. Although behavioral assays have demonstrated that feeding behavior is altered following exposure to drilling muds and petroleum fractions, there is no conclusive proof for a causal relationship between chemoreceptor interference and behavior deficits. The two techniques complement each other as pollution detection assays, perhaps reflecting a common interference mechanism. 42 references, 4 figures, 2 tables.

  15. Sex, Diet, and the Social Environment: Factors Influencing Hair Cortisol Concentration in Free-Ranging Black Bears (Ursus americanus.

    Directory of Open Access Journals (Sweden)

    Diana J R Lafferty

    Full Text Available Increasingly, measures of glucocorticoid levels (e.g., cortisol, key components of the neuroendocrine stress axis, are being used to measure past hypothalamic-pituitary-adrenal (HPA activity to index psychological and physiological stress exhibited by wildlife for assessing individual and population-level well-being. However, many intrinsic and extrinsic factors affect HPA activity in animals. Using American black bears (Ursus americanus; n = 116 as an ecological model and hair cortisol concentration (HCC as an integrative measure of past HPA activity, we evaluated the influence of diet, sex and the social environment on black bear HCC in a free-ranging population that spanned adjoining ecoregions with differing densities of potential conspecific and heterospecific competitors. HCC varied by sex, with female HCC ranging from 0.6 to 10.7 pg/mg (median = 4.5 ± 1.2 mean absolute deviation [MAD] and male HCC ranging from 0.5 to 35.1 pg/mg (median = 6.2 ± 2.6 MAD. We also observed a three-way interaction among sex, δ14C and ecoregion, which may indicate that some differences in HCC between female and male black bears results from variability in the nutritional needs of larger-bodied males relative to smaller-bodied females, slight differences in food resources use between ecoregions as well as sex-based differences regarding the social environment. Once we understand what drives sex-specific differences in HCC, HCC may aid our understanding of the physiological responses by bears and other wildlife to diverse environmental challenges.

  16. Expression, purification, and characterization of the Necator americanus aspartic protease-1 (Na-APR-1 (M74)) antigen, a component of the bivalent human hookworm vaccine.

    Science.gov (United States)

    Seid, Christopher A; Curti, Elena; Jones, R Mark; Hudspeth, Elissa; Rezende, Wanderson; Pollet, Jeroen; Center, Lori; Versteeg, Leroy; Pritchard, Sonya; Musiychuk, Konstantin; Yusibov, Vidadi; Hotez, Peter J; Bottazzi, Maria Elena

    2015-01-01

    Over 400 million people living in the world's poorest developing nations are infected with hookworms, mostly of the genus Necator americanus. A bivalent human hookworm vaccine composed of the Necator americanus Glutathione S-Transferase-1 (Na-GST-1) and the Necator americanus Aspartic Protease-1 (Na-APR-1 (M74)) is currently under development by the Sabin Vaccine Institute Product Development Partnership (Sabin PDP). Both monovalent vaccines are currently in Phase 1 trials. Both Na-GST-1 and Na-APR-1 antigens are expressed as recombinant proteins. While Na-GST-1 was found to express with high yields in Pichia pastoris, the level of expression of Na-APR-1 in this host was too low to be suitable for a manufacturing process. When the tobacco plant Nicotiana benthamiana was evaluated as an expression system, acceptable levels of solubility, yield, and stability were attained. Observed expression levels of Na-APR-1 (M74) using this system are ∼300 mg/kg. Here we describe the achievements and obstacles encountered during process development as well as characterization and stability of the purified Na-APR-1 (M74) protein and formulated vaccine. The expression, purification and analysis of purified Na-APR-1 (M74) protein obtained from representative 5 kg reproducibility runs performed to qualify the Na-APR-1 (M74) production process is also presented. This process has been successfully transferred to a pilot plant and a 50 kg scale manufacturing campaign under current Good Manufacturing Practice (cGMP) has been performed. The 50 kg run has provided a sufficient amount of protein to support the ongoing hookworm vaccine development program of the Sabin PDP.

  17. 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.

  18. Net neutrality and audiovisual services

    OpenAIRE

    van Eijk, N.; Nikoltchev, S.

    2011-01-01

    Net neutrality is high on the European agenda. New regulations for the communication sector provide a legal framework for net neutrality and need to be implemented on both a European and a national level. The key element is not just about blocking or slowing down traffic across communication networks: the control over the distribution of audiovisual services constitutes a vital part of the problem. In this contribution, the phenomenon of net neutrality is described first. Next, the European a...

  19. 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)...

  20. Progress report on the neutral beam radiation hardening study

    International Nuclear Information System (INIS)

    Lee, J.D.; Condit, R.H.; Hoenig, C.L.; Wilcox, T.P.; Erickson, J.

    1978-01-01

    A neutral beam injector as presently conceived directly views the plasma it is sustaining. In turn the injector is exposed to the primary fusion neutrons plus secondary neutrons and gammas streaming back up the neutral beam duct. The intent of this work is to examine representative beam lines to see how performance and lifetimes could be affected by this radiation environment and to determine how unacceptable effects could be alleviated. Potential radiation induced problems addressed in this report have been limited to: (1) overheating of cryopanels and insulators, (2) gamma flux induced electrical conductivity increase of insulators, and (3) neutron and gamma fluence induced damage to insulator materials

  1. On becoming neutral: effects of experimental neutralizing reconsidered.

    Science.gov (United States)

    van den Hout, M; van Pol, M; Peters, M

    2001-12-01

    Behaviour Research and Therapy 34 (1996) 889-898 found that writing out a negative thought produced anxiety and an urge to neutralize the thought, that instructing participants to neutralize the thought reduced anxiety/neutralization urge in the short run (i.e. within 2 min), but that in the control group 20 min without instruction was attended by the same reduction in anxiety/urge to neutralize ("natural decay"). The observations were made with pariticipants who scored high on "thought action fusion" and the experiment was set up as exerimental model of obsessions. We repeated the study with participants that were not selected on thought action fusion. All the findings reported by Behaviour Research and Therapy 34 (1996) 889-898 were replicated. Correlational analysis indicated that the strength of the effect was not related to scores on scales measuring "thought action fusion". Behaviour Research and Therapy 34 (1996) 889-898 did not assess whether non-neutralizing was followed by immediate reductions in distress. We did assess this and found that the larger part of the immediate reduction of distress after neutralization also occurs when no neutralization instruction is given. The effects of neutralization instructions in the present type of experiment are considerably less powerful than suggested earlier.

  2. 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

  3. Is science metaphysically neutral?

    Science.gov (United States)

    Fry, Iris

    2012-09-01

    This paper challenges the claim that science is metaphysically neutral upheld by contenders of the separation of peacefully co-existent science and religion and by evolutionary theists. True, naturalistic metaphysical claims can neither be refuted nor proved and are thus distinct from empirical hypotheses. However, metaphysical assumptions not only regulate the theoretical and empirical study of nature, but are increasingly supported by the growing empirical body of science. This historically evolving interaction has contributed to the development of a naturalistic worldview that renounces the necessity of a transcendent god and of purposeful design. The thesis presented here differs not only from the claims of the "separatists" and of evolutionary theists. In pointing to the metaphysical aspects of science, I also criticize the failure of some evolutionary naturalists to distinguish between empirical and metaphysical contentions. Most important, based on the examination of science suggested here, creationists' false accusation that science is only a naturalistic dogma is refuted. Finally, the difficulties involved in the position endorsed here for the public support of evolution are acknowledged, taking into account the high religious profile of the American society and the social and political context in the US and in other countries. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Post-mating interactions and their effects on fitness of female and male Echinothrips americanus (Thysanoptera: Thripidae), a new insect pest in China.

    Science.gov (United States)

    Li, Xiao-Wei; Jiang, Hong-Xue; Zhang, Xiao-Chen; Shelton, Anthony M; Feng, Ji-Nian

    2014-01-01

    Post-mating, sexual interactions of opposite sexes differ considerably in different organisms. Post-mating interactions such as re-mating behavior and male harassment can affect the fitness of both sexes. Echinothrips americanus is a new insect pest in Mainland China, and little is known about its post-mating interactions. In this study, we observed re-mating frequency and male harassment frequency and their effects on fitness parameters and offspring sex ratios of E. americanus females. Furthermore, we tested the impact of mating and post-mating interactions on fitness parameters of males. Our results revealed that the re-mating frequency in female adults was extremely low during a 30-day period. However, post-mating interactions between females and males, consisting mainly of male harassment and female resistance, did occur and significantly reduced female longevity and fecundity. Interestingly, increased access to males did not affect the ratio of female offspring. For males, mating dramatically reduced their longevity. However, post-mating interactions with females had no effects on the longevity of mated males. These results enrich our basic knowledge about female and male mating and post-mating behaviors in this species and provide important information about factors that may influence population regulation of this important pest species.

  5. Post-mating interactions and their effects on fitness of female and male Echinothrips americanus (Thysanoptera: Thripidae, a new insect pest in China.

    Directory of Open Access Journals (Sweden)

    Xiao-Wei Li

    Full Text Available Post-mating, sexual interactions of opposite sexes differ considerably in different organisms. Post-mating interactions such as re-mating behavior and male harassment can affect the fitness of both sexes. Echinothrips americanus is a new insect pest in Mainland China, and little is known about its post-mating interactions. In this study, we observed re-mating frequency and male harassment frequency and their effects on fitness parameters and offspring sex ratios of E. americanus females. Furthermore, we tested the impact of mating and post-mating interactions on fitness parameters of males. Our results revealed that the re-mating frequency in female adults was extremely low during a 30-day period. However, post-mating interactions between females and males, consisting mainly of male harassment and female resistance, did occur and significantly reduced female longevity and fecundity. Interestingly, increased access to males did not affect the ratio of female offspring. For males, mating dramatically reduced their longevity. However, post-mating interactions with females had no effects on the longevity of mated males. These results enrich our basic knowledge about female and male mating and post-mating behaviors in this species and provide important information about factors that may influence population regulation of this important pest species.

  6. The merits of neutral theory

    NARCIS (Netherlands)

    Alonso, D.; Etienne, R.S.; McKane, A.J.

    2006-01-01

    Hubbell's neutral theory of biodiversity has challenged the classic niche-based view of ecological community structure. Although there have been many attempts to falsify Hubbell's theory, we argue that falsification should not lead to rejection, because there is more to the theory than neutrality

  7. Neutral evolution of mutational robustness

    NARCIS (Netherlands)

    Nimwegen, Erik van; Crutchfield, James P.; Huynen, Martijn

    1999-01-01

    We introduce and analyze a general model of a population evolving over a network of selectively neutral genotypes. We show that the population s limit distribution on the neutral network is solely determined by the network topology and given by the principal eigenvector of the network

  8. Net neutrality and audiovisual services

    NARCIS (Netherlands)

    van Eijk, N.; Nikoltchev, S.

    2011-01-01

    Net neutrality is high on the European agenda. New regulations for the communication sector provide a legal framework for net neutrality and need to be implemented on both a European and a national level. The key element is not just about blocking or slowing down traffic across communication

  9. Seroepidemiologic study on the prevalence of Toxoplasma gondii and Trichinella spp. infections in black bears (Ursus americanus) in Pennsylvania, USA.

    Science.gov (United States)

    Dubey, Jitender P; Brown, Justin; Ternent, Mark; Verma, Shiv K; Hill, Dolores E; Cerqueira-Cézar, Camila K; Kwok, Oliver C H; Calero-Bernal, Rafael; Humphreys, Jan G

    2016-10-15

    The protozoan Toxoplasma gondii and the metazoan Trichinella spp. infect virtually all warm-blooded animals, including birds, humans, livestock, and marine mammals. Both parasitic infections can cause serious illness in human beings and can be acquired by ingesting under-cooked meat harboring infective stages. Approximately 3500 black bears (Ursus americanus) are legally-harvested each year in Pennsylvania, USA during the November hunting season. Among animals found infected with T. gondii, the prevalence of T. gondii is the highest among black bears in the USA; however, little is currently known of epidemiology of toxoplasmosis in this host species. Serum samples were collected during the winters of 2015 and 2016 from adult female bears and their nursing cubs or yearlings while they were still in their dens. Additionally, archived sera from bear samples collected throughout the year, including hunter-harvested bears in November and trapped bears in the summer, were serologically tested. Antibodies to T. gondii were assayed by the modified agglutination test (MAT, cut-off 1:25) and antibodies to Trichinella spp. were assayed using a commercial enzyme-linked immunosorbent assay (ELISA). Overall, T. gondii antibodies were found in 87.6% (206/235) of adults, and 44.1% (30/68) of yearlings. In March 2015/2016 sampling, antibodies to T. gondii were found in 94% (30/32) adult female bears while in their den. Antibodies were detected in 5% (3/66) of the nursing cubs in the dens of these sows. One positive cub had a MAT titer of 1:160 and two were positive at the 1:25 dilution but not at 1:50. The adult females of these cubs had MAT titers ranging from 1:400 to 1:3200. Antibodies to Trichinella spp. were found in 3% (6/181) of adults and 3.6% (1/28) of yearlings; these 7 bears were also seropositive for T. gondii. No antibodies to Trichinella spp. were detected in the sera of 44 nursing cubs tested. The finding of T. gondii antibodies in only 3 of 66 cubs, and higher

  10. THE USE OF KETAMINE-XYLAZINE OR BUTORPHANOL-AZAPERONE-MEDETOMIDINE TO IMMOBILIZE AMERICAN BLACK BEARS ( URSUS AMERICANUS).

    Science.gov (United States)

    Williamson, Ryan H; Muller, Lisa L; Blair, Coy

    2018-04-04

      Wildlife anesthetic protocols must offer rapid inductions and recoveries, be physiologically safe, and be minimally regulated. With this in mind, we evaluated differences in induction and recovery times and physiological parameters in 33 American black bears ( Ursus americanus) anesthetized with ketamine-xylazine (KX) or immobilized with a commercial drug combination of butorphanol, azaperone, and medetomidine (BAM). Dose was based on mass estimated from field observations. Bears were housed at Appalachian Bear Rescue, Townsend, Tennessee, US, or free-ranging within the Great Smoky Mountains National Park (Tennessee and North Carolina, US) and chemically immobilized for management purposes. From 11 April to 29 June 2016, we immobilized bears with injection via pole syringe or disposable dart projected from an air-powered dart rifle. Once immobilized, we measured each bear's temperature, respiration (breaths/min), heart rate (beats/min), hemoglobin oxygen saturation (via pulse oximetry), arterial blood gases, and mass (kg). We found no differences in the induction parameters, partial pressures of CO 2 , and rectal temperatures. The BAM-treated bears had lower heart and respiratory rates that led to lower hemoglobin oxygen saturation levels (from blood gas analysis, SaO 2 ). The SaO 2 after treatment with BAM (91.1±0.8%) was lower than with KX (93.4±0.9%). After handling, we reversed KX-treated bears with a x̄=0.2±0.02 mg/kg yohimbine and BAM-treated bears with x̄=1.5±0.1 mg/kg atipamezole and 0.8±0.1 mg/kg naltrexone. We found no differences in the recovery times to increased respiration and to the bear assuming a head-up position. The BAM-treated bears stood and recovered quicker than did KX-treated animals. Based on our observations, BAM appears to offer safe, predictable immobilizations with fewer drawbacks and faster recovery times than KX-treated bears.

  11. Genetic Characterization of Sarcoptes scabiei from Black Bears (Ursus americanus) and Other Hosts in the Eastern United States.

    Science.gov (United States)

    Peltier, Sarah K; Brown, Justin D; Ternent, Mark; Niedringhaus, Kevin D; Schuler, Krysten; Bunting, Elizabeth M; Kirchgessner, Megan; Yabsley, Michael J

    2017-10-01

    Since the early 1990s there has been an increase in the number of cases and geographic expansion of severe mange in the black bear (Ursus americanus) population in Pennsylvania. Although there are 3 species of mites associated with mange in bears, Sarcoptes scabiei has been identified as the etiologic agent in these Pennsylvania cases. Historically, S. scabiei-associated mange in bears has been uncommon and sporadic, although it is widespread and relatively common in canid populations. To better understand this recent emergence of sarcoptic mange in bears in Pennsylvania and nearby states, we genetically characterized S. scabiei samples from black bears in the eastern United States. These sequences were compared with newly acquired S. scabiei sequences from wild canids (red fox [Vulpes vulpes] and coyote [Canis latrans]) and a porcupine (Erethizon dorsatum) from Pennsylvania and Kentucky and also existing sequences in GenBank. The internal transcribed spacer (ITS)-2 region and cytochrome c oxidase subunit 1 (cox1) gene were amplified and sequenced. Twenty-four ITS-2 sequences were obtained from mites from bears (n = 16), red fox (n = 5), coyote (n = 2), and a porcupine. The sequences from bear samples were identical to each other or differed only at polymorphic bases, whereas S. scabiei from canids were more variable, but 2 were identical to S. scabiei sequences from bears. Eighteen cox1 sequences obtained from mites from bears represented 6 novel haplotypes. Phylogenetic analysis of cox1 sequences revealed 4 clades: 2 clades of mites of human origin from Panama or Australia, a clade of mites from rabbits from China, and a large unresolved clade that included the remaining S. scabiei sequences from various hosts and regions, including sequences from the bears from the current study. Although the cox1 gene was more variable than the ITS-2, phylogenetic analyses failed to detect any clustering of S. scabiei from eastern U.S. hosts. Rather, sequences from black bears

  12. HIV-1 binding and neutralizing antibodies of injecting drug users

    Directory of Open Access Journals (Sweden)

    E.P. Ouverney

    2005-09-01

    Full Text Available Previous studies have demonstrated a stronger seroreactivity against some synthetic peptides responsible for inducing neutralizing antibodies in injecting drug users (IDU compared to that of individuals sexually infected with HIV-1 (S, but the effectiveness in terms of the neutralizing ability of these antibodies has not been evaluated. Our objective was to study the humoral immune response of IDU by determining the specificity of their antibodies and the presence of neutralizing antibodies. The neutralization capacity against the HIV-1 isolate MN (genotype B, the primary HIV-1 isolate 95BRRJ021 (genotype F, and the seroreactivity with peptides known to induce neutralizing antibodies, from the V2 and V3 loops of different HIV-1 subtypes, were analyzed. Seroreactivity indicates that IDU plasma are more likely to recognize a broader range of peptides than S plasma, with significantly higher titers, especially of V3 peptides. Similar neutralization frequencies of the MN isolate were observed in plasma of the IDU (16/47 and S (20/60 groups in the 1:10 dilution. The neutralization of the 95BRRJ021 isolate was more frequently observed for plasma from the S group (15/23 than from the IDU group (15/47, P = 0.0108. No correlation between neutralization and seroreactivity with the peptides tested was observed. These results suggest that an important factor responsible for the extensive and broad humoral immune response observed in IDU is their infection route. There was very little difference in neutralizing antibody response between the IDU and S groups despite their differences in seroreactivity and health status.

  13. Is an inequality-neutral flat tax reform really neutral?

    OpenAIRE

    Juan Prieto Rodríguez; Juan Gabriel Rodríguez; Rafael Salas

    2004-01-01

    . Let us assume a revenue- and inequality-neutral flat tax reform shifting from a graduated-rate tax. Is this reform really neutral in terms of the income distribution? Traditionally, there has been a bias toward the inequality analysis, forgetting other relevant aspects of the income distribution. This kind of reforms implies a set of composite transfers, both progressive and regressive, even though inequality remains unchanged. This paper shows that polarization is a useful tool for charact...

  14. Induction of human immunodeficiency virus neutralizing antibodies using fusion complexes.

    Science.gov (United States)

    Zipeto, Donato; Matucci, Andrea; Ripamonti, Chiara; Scarlatti, Gabriella; Rossolillo, Paola; Turci, Marco; Sartoris, Silvia; Tridente, Giuseppe; Bertazzoni, Umberto

    2006-05-01

    Human immunodeficiency virus-1 (HIV-1) infects cells by membrane fusion that is mediated by the envelope proteins gp120/gp41 and the cellular receptors CD4 and CCR5. During this process, some conserved viral epitopes are temporarily exposed and may induce a neutralizing antibody response when fixed in the fusogenic conformation. These transient structures are conserved and may be effective antigens for use in an anti-HIV-1 vaccine. In this study we tested different conditions of preparation of fusion complexes inducing neutralizing antibodies against both R5 and X4 tropic HIV-1 strains. Cell lines expressing HIV-1 gp120/gp41 and CD4-CCR5 were prepared and conditions for producing fusion complexes were tested. Complexes produced at different temperature and fixative combinations were used to immunize mice. Results indicated that (a) fusion complexes prepared at either 21 degrees C, 30 degrees C or 37 degrees C were immunogenic and induced neutralizing antibodies against both R5 and X4 HIV-1 heterologous isolates; (b) after extensive purification of antibodies there was no cytotoxic effect; (c) complexes prepared at 37 degrees C were more immunogenic and induced higher titers of neutralizing antibodies than complexes prepared at either 21 degrees C or 30 degrees C; (d) the fixative used did not affect the titer of neutralizing antibodies except for glutaraldehyde which was ineffective; (e) the neutralizing activity was retained after CD4-CCR5 antibody removal. The production of higher titers of neutralizing antibody with fusion complexes prepared at 37 degrees C, as compared to lower temperatures, may be related to the induction of antibodies against many different conformation intermediates that subsequently act synergistically at different steps in the fusion process.

  15. Neutral beam current drive with balanced injection

    International Nuclear Information System (INIS)

    Eckhartt, D.

    1990-01-01

    Current drive with fast ions has proved its capability to sustain a tokamak plasma free of externally induced electric fields in a stationary state. The suprathermal ion population within the toroidal plasma was created by quasi-tangential and uni-directional injection of high-energy neutral atoms, their ionisation and subsequent deceleration by collisions with the background plasma particles. In future large tokamaks of the NET/INTER-type, with reactor-relevant values of plasma density and temperature, this current drive scheme is expected to maintain the toroidal current at the plasma centre, as current drive by lower hybrid waves will be restricted to the outer plasma regions owing to strong wave damping. Adequate penetration of the neutral atoms through the dense plasma requires particle energies of several hundred kilovolts per nucleon since beam absorption scales roughly with the ratio beam energy over density. The realisation of such high-energy high-power neutral beams, based on negative ion technology, is now under study. (author) 7 refs., 2 figs

  16. Development and evaluation of a Loop Mediated Isothermal Amplification (LAMP) technique for the detection of hookworm (Necator americanus) infection in fecal samples.

    Science.gov (United States)

    Mugambi, Robert Muriuki; Agola, Eric L; Mwangi, Ibrahim N; Kinyua, Johnson; Shiraho, Esther Andia; Mkoji, Gerald M

    2015-11-06

    Hookworm infection is a major concern in sub-Saharan Africa, particularly in children and pregnant women. Necator americanus and Ancylostoma duodenale are responsible for this condition. Hookworm disease is one of the Neglected tropical diseases (NTDs) that are targeted for elimination through global mass chemotherapy. To support this there is a need for reliable diagnostic tools. The conventional diagnostic test, Kato-Katz that is based on microscopic detection of parasite ova in faecal samples, is not effective due to its low sensitivity that is brought about mainly by non-random distribution of eggs in stool and day to day variation in egg output. It is tedious, cumbersome to perform and requires experience for correct diagnosis. LAMP-based tests are simple, relatively cheap, offer greater sensitivity, specificity than existing tests, have high throughput capability, and are ideal for use at the point of care. We have developed a LAMP diagnostic test for detection of hookworm infection in faecal samples. LAMP relies on auto cycling strand displacement DNA synthesis performed at isothermal temperature by Bst polymerase and a set of 4 specific primers. The primers used in the LAMP assay were based on the second Internal Transcribed Spacer (ITS-2) region and designed using Primer Explorer version 4 Software. The ITS-2 region of the ribosomal gene (rDNA) was identified as a suitable target due to its low mutation rates and substantial differences between species. DNA was extracted directly from human faecal samples, followed by LAMP amplification at isothermal temperature of 63 °C for 1 h. Amplicons were visualized using gel electrophoresis and SYBR green dye. Both specificity and sensitivity of the assay were determined. The LAMP based technique developed was able to detect N. americanus DNA in faecal samples. The assay showed 100 % specificity and no cross-reaction was observed with other helminth parasites (S. mansoni, A. lumbricoides or T. trichiura). The

  17. 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

  18. Net Neutrality: Background and Issues

    National Research Council Canada - National Science Library

    Gilroy, Angele A

    2006-01-01

    .... The move to place restrictions on the owners of the networks that compose and provide access to the Internet, to ensure equal access and nondiscriminatory treatment, is referred to as "net neutrality...

  19. Styrax americanus Lam.

    Science.gov (United States)

    K.F Connor

    2004-01-01

    American snowbell, also known as mock orange or storax, is a deciduous shrub or small tree with a widely branched crown. It reaches 3 to 5 m in height, and the stems can reach 7.5 cm in diameter. While the bark on the stems is smooth and dark grey to brown, branches range in color from green to grey to red-brown. Young stems are pubescent, becoming glabrous with age....

  20. 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

  1. Estrutura populacional e biologia reprodutiva de Menticirrhus americanus (Linnaeus, 1758 (Teleostei, Sciaenidae na baía de Ubatuba-Enseada, Santa Catarina, Brasil

    Directory of Open Access Journals (Sweden)

    Matheus Oliveira Freitas

    2011-01-01

    primeira maturação gonadal (L50 foi estimado em 16,7cm para fêmeas e 15,4cm para machos. O período reprodutivo ocorreu nas estações quentes, e a espécie apresentou desova múltipla. O índice hepatossomático apresentou variação sazonal similar à descrita para o índice gonadossomático, e pode ser considerado bom indicador da desova. O fator de condição não foi um bom indicador do período de desova, mas esteve relacionado com o processo de recuperação e maturação das gônadas. Características da dinâmica populacional mostraram que M. americanus utiliza a área de estudo para reprodução e recrutamento.

  2. Tainting and depuration of taint by lobsters (Homarus americanus) exposed to water contaminated with a No.2 Fuel Oil: Relationship with aromatic hydrocarbon content in tissue

    International Nuclear Information System (INIS)

    Williams, U.P.; Kiceniuk, J.W.; Fancey, L.L.; Botta, J.R.

    1989-01-01

    Lobsters (Homarus americanus) were exposed to a pulse of diesel oil and held for 21 days to depurate. Taste panels revealed a highly significant difference between samples, as well as a preferences for, the untreated samples at days 10 and 11. The odor of the raw treated samples differed significantly from that of the control at each of the sampling times. Cooking appeared to remove the oily odor from the raw lobster. Significantly elevated concentrations of total aromatics were found in the hepatopancreas of both sexes at days 3-4 and 10-11 and in the tail muscle of male and female lobsters 10-11 days after initial exposure and decreased thereafter. Tainting of lobsters can occur within 10 days of exposure to diesel, and this effect can be reversed within 20 days after initial exposure

  3. Inhibition of Neutral Red Photolysis with Different Antioxidants

    Directory of Open Access Journals (Sweden)

    Zlatan Rimpapa

    2007-02-01

    Full Text Available Neutral red is a dye the azine structure which has been used as an acido-base indicator and a dye in histochemistry. In 1960 Goldhaber introduced Neutral red into the medium of resorbing bone cultures to localize the osteoclast in the living cultures. Using time-lapse microcinematography in order to follow the osteoclasts, he reported excellent contrast could be obtained with Neutral red due to the avidity of osteoclasts for this dye. Unfortunately, however, the photodynamic effect resulting from subsequent exposure of these cultures to light precluded this approach, and again in 1963. it was observed that the death of the osteoclasts was probably due to a photodynamic effect related to the dye in the cell, the presence of oxygen and the frequent exposure of light by our time-lapse photography. VIS and UV irradiation induced photolysis of Neutral red, and from Neutral red cation produced with photons a Neutral red radical. This Neutral red radical can be inhibited with action of an antioxidant, such as melatonin, glutathione, ascorbic acid, E vitamin, etc. We developed an assay with Neutral redphotolysis which utilizes a VIS and UV irradiation technique for quantification the inhibition of photolysis with action of an antioxidant. In this method Neutral red acts double, as a free radical generator and as a photosensitizer.

  4. Ulcerative enteritis in Homarus americanus: case report and molecular characterization of intestinal aerobic bacteria of apparently healthy lobsters in live storage.

    Science.gov (United States)

    Battison, Andrea L; Després, Béatrice M; Greenwood, Spencer J

    2008-10-01

    An intermoult male American lobster, Homarus americanus, with severe intestinal lesions was encountered while collecting samples of aerobic intestinal bacteria from lobsters held in an artificial sea-water recirculation aquarium system. Grossly, the intestine was firm, thickened, and white. Histologic examination revealed a severe, diffuse, ulcerative enteritis which spared the chitin-lined colon, somewhat similar to hemocytic enteritis of shrimp. The bacterial isolates from this lobster were compared to 11 other lobsters lacking gross intestinal lesions. Two organisms, one identified as Vibrio sp. and another most similar to an uncultured proteobacterium (98.9%), clustering with Rhanella and Serratia species using 16S rDNA PCR, were isolated from the intestines of the 11, grossly normal, lobsters and the affected lobster. An additional two intestinal isolates were cultured only from the lobster with ulcerative enteritis. One, a Flavobacterium, similar to Lutibacter litoralis (99.3%), possibly represented a previously described commensal of the distal intestine. The second, a Vibrio sp., was unique to the affected animal. While the etiology of the ulcerative enteritis remains undetermined, this report represents the first description of gross and histologic findings in H. americanus of a condition which has morphologic similarities to hemocytic enteritis of shrimp. An additional observation was a decrease in the number of intestinal isolates recovered from the 11 apparently healthy lobsters compared to that previously reported for recently harvested lobster. More comprehensive studies of the relationship between the health of lobsters, gut microbial flora and the husbandry and environment maintained within holding units are warranted.

  5. Crystallization and preliminary X-ray analysis of Na-ASP-1, a multi-domain pathogenesis-related-1 protein from the human hookworm parasite Necator americanus

    International Nuclear Information System (INIS)

    Asojo, Oluwatoyin A.; Loukas, Alex; Inan, Mehmet; Barent, Rick; Huang, Jicai; Plantz, Brad; Swanson, Amber; Gouthro, Mark; Meagher, Michael M.; Hotez, Peter J.

    2005-01-01

    In order to clarify the structural basis of the pathogenesis-related-1 domain, Na-ASP-1, the first multi-domain ASP from the human hookworm parasite N. americanus, has been crystallized. 2.2 Å resolution data have been collected from a crystal belonging to the monoclinic space group P2 1 . Human hookworm infection is a major cause of anemia and malnutrition in the developing world. In an effort to control hookworm infection, the Human Hookworm Vaccine Initiative has identified candidate vaccine antigens from the infective larval stage (L3) of the parasite, including a family of pathogenesis-related-1 (PR-1) proteins known as the ancylostoma-secreted proteins (ASPs). The functions of the ASPs are unknown. In addition, it is unclear why some ASPs have one while others have multiple PR-1 domains. There are no known structures of a multi-domain ASP and in an effort to remedy this situation, recombinant Na-ASP-1 has been expressed, purified and crystallized. Na-ASP-1 is a 406-amino-acid multi-domain ASP from the prevalent human hookworm parasite Necator americanus. Useful X-ray data to 2.2 Å have been collected from a crystal that belongs to the monoclinic space group P2 1 with unit-cell parameters a = 67.7, b = 74.27, c = 84.60 Å, β = 112.12°. An initial molecular-replacement solution has been obtained with one monomer in the asymmetric unit

  6. Crystallization and preliminary X-ray analysis of Na-ASP-1, a multi-domain pathogenesis-related-1 protein from the human hookworm parasite Necator americanus

    Energy Technology Data Exchange (ETDEWEB)

    Asojo, Oluwatoyin A., E-mail: oasojo@unmc.edu [Eppley Institute for Research in Cancer and Allied Diseases, 987696 Nebraska Medical Center, Omaha, NE 68198-7696 (United States); Loukas, Alex [Department of Microbiology and Tropical Medicine, The George Washington University Medical Center, Washington DC 20037 (United States); Division of Infectious Diseases and Immunology, Queensland Institute of Medical Research, Brisbane, QLD 4006 (Australia); Inan, Mehmet; Barent, Rick; Huang, Jicai; Plantz, Brad; Swanson, Amber; Gouthro, Mark; Meagher, Michael M. [Department of Chemical Engineering, The University of Nebraska-Lincoln, Lincoln, NE 68588-0643 (United States); Hotez, Peter J. [Department of Microbiology and Tropical Medicine, The George Washington University Medical Center, Washington DC 20037 (United States); Eppley Institute for Research in Cancer and Allied Diseases, 987696 Nebraska Medical Center, Omaha, NE 68198-7696 (United States)

    2005-04-01

    In order to clarify the structural basis of the pathogenesis-related-1 domain, Na-ASP-1, the first multi-domain ASP from the human hookworm parasite N. americanus, has been crystallized. 2.2 Å resolution data have been collected from a crystal belonging to the monoclinic space group P2{sub 1}. Human hookworm infection is a major cause of anemia and malnutrition in the developing world. In an effort to control hookworm infection, the Human Hookworm Vaccine Initiative has identified candidate vaccine antigens from the infective larval stage (L3) of the parasite, including a family of pathogenesis-related-1 (PR-1) proteins known as the ancylostoma-secreted proteins (ASPs). The functions of the ASPs are unknown. In addition, it is unclear why some ASPs have one while others have multiple PR-1 domains. There are no known structures of a multi-domain ASP and in an effort to remedy this situation, recombinant Na-ASP-1 has been expressed, purified and crystallized. Na-ASP-1 is a 406-amino-acid multi-domain ASP from the prevalent human hookworm parasite Necator americanus. Useful X-ray data to 2.2 Å have been collected from a crystal that belongs to the monoclinic space group P2{sub 1} with unit-cell parameters a = 67.7, b = 74.27, c = 84.60 Å, β = 112.12°. An initial molecular-replacement solution has been obtained with one monomer in the asymmetric unit.

  7. Gas cell neutralizers (Fundamental principles)

    International Nuclear Information System (INIS)

    Fuehrer, B.

    1985-06-01

    Neutralizing an ion-beam of the size and energy levels involved in the neutral-particle-beam program represents a considerable extension of the state-of-the-art of neutralizer technology. Many different mediums (e.g., solid, liquid, gas, plasma, photons) can be used to strip the hydrogen ion of its extra electron. A large, multidisciplinary R and D effort will no doubt be required to sort out all of the ''pros and cons'' of these various techniques. The purpose of this particular presentation is to discuss some basic configurations and fundamental principles of the gas type of neutralizer cell. Particular emphasis is placed on the ''Gasdynamic Free-Jet'' neutralizer since this configuration has the potential of being much shorter than other type of gas cells (in the beam direction) and it could operate in nearly a continuous mode (CW) if necessary. These were important considerations in the ATSU design which is discussed in some detail in the second presentation entitled ''ATSU Point Design''

  8. 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

  9. Dynamics of neutral and charged aerosol particles

    Energy Technology Data Exchange (ETDEWEB)

    Leppae, J.

    2012-07-01

    Atmospheric aerosol particles have various climate effects and adverse health effects, which both depend on the size and number concentration of the particles. Freshly-formed particles are not large enough to impact neither health nor climate and they are most susceptible to removal by collisions with larger pre-existing particles. Consequently, the knowledge of both the formation and the growth rate of particles are crucially important when assessing the health and climate effects of atmospheric new particle formation. The purpose of this thesis is to increase our knowledge of the dynamics of neutral and charged aerosol particles with a specific interest towards the particle growth rate and processes affecting the aerosol charging state. A new model, Ion-UHMA, which simulates the dynamics of neutral and charged particles, was developed for this purpose. Simple analytical formulae that can be used to estimate the growth rate due to various processes were derived and used to study the effects of charged particles on the growth rate. It was found that the growth rate of a freshly-formed particle population due to condensation and coagulation could be significantly increased when a considerable fraction of the particles are charged. Finally, recent data-analysis methods that have been applied to the aerosol charging states obtained from the measurements were modified for a charge asymmetric framework. The methods were then tested on data obtained from aerosol dynamics simulations. The methods were found to be able to provide reasonable estimates on the growth rate and proportion of particles formed via ion-induced nucleation, provided that the growth rate is high enough and that the charged particles do not grow much more rapidly than the neutral ones. A simple procedure for estimating whether the methods are suitable for analysing data obtained in specific conditions was provided. In this thesis, the dynamics of neutral and charged aerosol particles were studied in

  10. Cryptic nature of a conserved, CD4-inducible V3 loop neutralization epitope in the native envelope glycoprotein oligomer of CCR5-restricted, but not CXCR4-using, primary human immunodeficiency virus type 1 strains.

    Science.gov (United States)

    Lusso, Paolo; Earl, Patricia L; Sironi, Francesca; Santoro, Fabio; Ripamonti, Chiara; Scarlatti, Gabriella; Longhi, Renato; Berger, Edward A; Burastero, Samuele E

    2005-06-01

    The external subunit of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env), gp120, contains conserved regions that mediate sequential interactions with two cellular receptor molecules, CD4 and a chemokine receptor, most commonly CCR5 or CXCR4. However, antibody accessibility to such regions is hindered by diverse protective mechanisms, including shielding by variable loops, conformational flexibility and extensive glycosylation. For the conserved neutralization epitopes hitherto described, antibody accessibility is reportedly unrelated to the viral coreceptor usage phenotype. Here, we characterize a novel, conserved gp120 neutralization epitope, recognized by a murine monoclonal antibody (MAb), D19, which is differentially accessible in the native HIV-1 Env according to its coreceptor specificity. The D19 epitope is contained within the third variable (V3) domain of gp120 and is distinct from those recognized by other V3-specific MAbs. To study the reactivity of MAb D19 with the native oligomeric Env, we generated a panel of PM1 cells persistently infected with diverse primary HIV-1 strains. The D19 epitope was conserved in the majority (23/29; 79.3%) of the subtype-B strains tested, as well as in selected strains from other genetic subtypes. Strikingly, in CCR5-restricted (R5) isolates, the D19 epitope was invariably cryptic, although it could be exposed by addition of soluble CD4 (sCD4); epitope masking was dependent on the native oligomeric structure of Env, since it was not observed with the corresponding monomeric gp120 molecules. By contrast, in CXCR4-using strains (X4 and R5X4), the epitope was constitutively accessible. In accordance with these results, R5 isolates were resistant to neutralization by MAb D19, becoming sensitive only upon addition of sCD4, whereas CXCR4-using isolates were neutralized regardless of the presence of sCD4. Other V3 epitopes examined did not display a similar divergence in accessibility based on

  11. Measurement of plasma production and neutralization in gas neutralizers

    International Nuclear Information System (INIS)

    Maor, D.; Meron, M.; Johnson, B.; Jones, K.; Agagu, A.; Hu, B.

    1986-01-01

    In order to satisfy the need of experimental data for the designing of gas neutralizers we have started a project aimed at measuring all relevant cross sections for the charge exchange of H - , H 0 and H + projectiles, as well as the cross sections for the production of ions in the target. The expected results of these latter measurements are shown schematically

  12. 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.)

  13. 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)

  14. 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

  15. Climate Neutral Research Campuses | NREL

    Science.gov (United States)

    the background. Set an example for climate neutrality. Use NREL's climate action planning process and more. Climate Action Planning Process Identify the best technology options for a climate action plan . Climate Action Planning Tool Identify the best technology options for a climate action plan. Technology

  16. 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

  17. Neutral Models with Generalised Speciation

    NARCIS (Netherlands)

    Haegeman, Bart; Etienne, Rampal S.

    Hubbell's neutral theory claims that ecological patterns such as species abundance distributions can be explained by a stochastic model based on simple assumptions. One of these assumptions, the point mutation assumption, states that every individual has the same probability to speciate. Etienne et

  18. Multimegawatt neutral beams for tokamaks

    International Nuclear Information System (INIS)

    Kunkel, W.B.

    1979-03-01

    Most of the large magnetic confinement experiments today and in the near future use high-power neutral-beam injectors to heat the plasma. This review briefly describes this remarkable technique and summarizes recent results as well as near term expectations. Progress has been so encouraging that it seems probable that tokamaks will achieve scientific breakeven before 1990

  19. Heavy neutral leptons at FASER

    Science.gov (United States)

    Kling, Felix; Trojanowski, Sebastian

    2018-05-01

    We study the prospects for discovering heavy neutral leptons at Forward Search Experiment (FASER), the newly proposed detector at the LHC. Previous studies showed that a relatively small detector with ˜10 m length and ≲1 m2 cross sectional area can probe large unconstrained parts of parameter space for dark photons and dark Higgs bosons. In this work, we show that FASER will also be sensitive to heavy neutral leptons that have mixing angles with the active neutrinos that are up to an order of magnitude lower than current bounds. In particular, this is true for heavy neutral leptons produced dominantly in B -meson decays, in which case FASER's discovery potential is comparable to the proposed SHiP detector. We also illustrate how the search for heavy neutral leptons at FASER will be complementary to ongoing searches in high-pT experiments at the LHC and can shed light on the nature of dark matter and the process of baryogenesis in the early Universe.

  20. 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.

  1. The manipulation of neutral particles

    International Nuclear Information System (INIS)

    Chu, S.

    1998-01-01

    The article is a translation of the lecture delivered on the occasion of the 1997 Nobel Prize awarding ceremony. The author's personal contribution to the discovery of laser cooling and trapping of neutral atoms is described, and applications of this phenomenon in atomic physics are highlighted. The article is completed by Mr. Steven Chu's autobiography

  2. 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

  3. Novel Epstein-Barr virus-like particles incorporating gH/gL-EBNA1 or gB-LMP2 induce high neutralizing antibody titers and EBV-specific T-cell responses in immunized mice.

    Science.gov (United States)

    Perez, Elizabeth M; Foley, Joslyn; Tison, Timelia; Silva, Rute; Ogembo, Javier Gordon

    2017-03-21

    Previous Epstein-Barr virus (EBV) prophylactic vaccines based on the major surface glycoprotein gp350/220 as an immunogen have failed to block viral infection in humans, suggesting a need to target other viral envelope glycoproteins. In this study, we reasoned that incorporating gH/gL or gB, critical glycoproteins for viral fusion and entry, on the surface of a virus-like particle (VLP) would be more immunogenic than gp350/220 for generating effective neutralizing antibodies to prevent viral infection of both epithelial and B cell lines. To boost the humoral response and trigger cell-mediated immunity, EBV nuclear antigen 1 (EBNA1) and latent membrane protein 2 (LMP2), intracellular latency proteins expressed in all EBV-infected cells, were also included as critical components of the polyvalent EBV VLP. gH/gL-EBNA1 and gB-LMP2 VLPs were efficiently produced in Chinese hamster ovary cells, an FDA-approved vehicle for mass-production of biologics. Immunization with gH/gL-EBNA1 and gB-LMP2 VLPs without adjuvant generated both high neutralizing antibody titers in vitro and EBV-specific T-cell responses in BALB/c mice. These data demonstrate that will be invaluable not only in preventing EBV infection, but importantly, in preventing and treating the 200,000 cases of EBV-associated cancers that occur globally every year.

  4. Non-Neutralizing Antibodies Directed against HIV and Their Functions

    Directory of Open Access Journals (Sweden)

    Luzia M. Mayr

    2017-11-01

    Full Text Available B cells produce a plethora of anti-HIV antibodies (Abs but only few of them exhibit neutralizing activity. This was long considered a profound limitation for the enforcement of humoral immune responses against HIV-1 infection, especially since these neutralizing Abs (nAbs are extremely difficult to induce. However, increasing evidence shows that additional non-neutralizing Abs play a significant role in decreasing the viral load, leading to partial and sometimes even total protection. Mechanisms suspected to participate in protection are numerous. They involve the Fc domain of Abs as well as their Fab part, and consequently the induced Ab isotype will be determinant for their functions, as well as the quantity and quality of the Fc-receptors (FcRs expressed on immune cells. Fc-mediated inhibitory functions, such as Ab-dependent cellular cytotoxicity, antibody-dependent cellular phagocytosis, aggregation, and even immune activation have been proposed. However, as for nAbs, the non-neutralizing activities are limited to a subset of anti-HIV Abs. An improved in-depth characterization of the Abs displaying these functional responses is required for the development of new vaccination strategies, which aim to selectively trigger the B cells able to induce the right functional Ab combinations both at the right place and at the right time. This review summarizes our current knowledge on non-neutralizing functional inhibitory Abs and discusses the potential benefit of inducing them via vaccination. We also provide new insight into the roles of the FcγR-mediated Ab therapeutics in clinical trials for HIV diseases.

  5. Characterization of Neutral Radicals from a Dissociative Electron Attachment Process

    Science.gov (United States)

    Li, Zhou; Milosavljević, Aleksandar R.; Carmichael, Ian; Ptasinska, Sylwia

    2017-08-01

    Despite decades of gas-phase studies on dissociative electron attachment (DEA) to various molecules, as yet there has been no direct detection and characterization of the neutral radical species produced by this process. In this study, we performed stepwise electron spectroscopy to directly measure and characterize the neutrals produced upon zero-electron-energy DEA to the model molecule, carbon tetrachloride (CCl4 ). We observed the direct yield of the trichloromethyl radical (CCl3. ) formed by DEA to CCl4 and measured the appearance energies of all the other neutral species. By combining these experimental findings with high-level quantum chemical calculations, we performed a complete analysis of both the DEA to CCl4 and the subsequent electron-impact ionization of CCl3. . This work paves the way toward a complete experimental characterization of DEA processes, which will lead to a better understanding of the low-energy electron-induced formation of radical species.

  6. 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

  7. 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...

  8. Neutral particles identification at LHCb

    CERN Multimedia

    Quintana, Boris Julien

    2018-01-01

    Important analyses of the core LHCb physics program rely on calorimetry to identify photons, high-energy neutral pions and electrons. For this purpose, the LHCb calorimeter system is composed of a scintillating pad plane, a preshower detector, an electromagnetic and a hadronic sampling calorimeters. The interaction of a given particle in these detectors leaves a specific signature. This is exploited for particle identification (PID) by combining calorimeters and tracking information into multi-variate classifiers. In this contribution, we focus on the identification of photons against high-energy neutral pion and hadronic backgrounds. Performance on Run 1 data will be shown. Small discrepancies with simulation predictions are then discussed, with special emphasis on the methods to correctly estimate PID cut efficiencies by means of large calibration samples of abundant beauty and charm decays to final states with photons. Finally, the technical aspects of the collection of these samples in Run 2 are presented...

  9. 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

  10. Steady state neutral beam injector

    International Nuclear Information System (INIS)

    Mattoo, S.K.; Bandyopadhyay, M.; Baruah, U.K.; Bisai, N.; Chakbraborty, A.K.; Chakrapani, Ch.; Jana, M.R.; Bajpai, M.; Jaykumar, P.K.; Patel, D.; Patel, G.; Patel, P.J.; Prahlad, V.; Rao, N.V.M.; Rotti, C.; Singh, N.P.; Sridhar, B.

    2000-01-01

    Learning from operational reliability of neutral beam injectors in particular and various heating schemes including RF in general on TFTR, JET, JT-60, it has become clear that neutral beam injectors may find a greater role assigned to them for maintaining the plasma in steady state devices under construction. Many technological solutions, integrated in the present day generation of injectors have given rise to capability of producing multimegawatt power at many tens of kV. They have already operated for integrated time >10 5 S without deterioration in the performance. However, a new generation of injectors for steady state devices have to address to some basic issues. They stem from material erosion under particle bombardment, heat transfer > 10 MW/m 2 , frequent regeneration of cryopanels, inertial power supplies, data acquisition and control of large volume of data. Some of these engineering issues have been addressed to in the proposed neutral beam injector for SST-1 at our institute; the remaining shall have to wait for the inputs of the database generated from the actual experience with steady state injectors. (author)

  11. 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

  12. Assaying Cellular Viability Using the Neutral Red Uptake Assay.

    Science.gov (United States)

    Ates, Gamze; Vanhaecke, Tamara; Rogiers, Vera; Rodrigues, Robim M

    2017-01-01

    The neutral red uptake assay is a cell viability assay that allows in vitro quantification of xenobiotic-induced cytotoxicity. The assay relies on the ability of living cells to incorporate and bind neutral red, a weak cationic dye, in lysosomes. As such, cytotoxicity is expressed as a concentration-dependent reduction of the uptake of neutral red after exposure to the xenobiotic under investigation. The neutral red uptake assay is mainly used for hazard assessment in in vitro toxicology applications. This method has also been introduced in regulatory recommendations as part of 3T3-NRU-phototoxicity-assay, which was regulatory accepted in all EU member states in 2000 and in the OECD member states in 2004 as a test guideline (TG 432). The present protocol describes the neutral red uptake assay using the human hepatoma cell line HepG2, which is often employed as an alternative in vitro model for human hepatocytes. As an example, the cytotoxicity of acetaminophen and acetyl salicylic acid is assessed.

  13. 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.

  14. The Neutral Interest Rate: Estimates for Chile

    OpenAIRE

    Rodrigo Fuentes S; Fabián Gredig U.

    2008-01-01

    To estimate the neutral real interest rate for Chile, we use a variety of methods that can be classified into three categories: those derived from economic theory, the neutral rate implicit in financial assets, and statistical procedures using macroeconomic data. We conclude that the neutral rate is not constant over time, but it is closely related with—though not equivalent to—the potential GDP growth rate. The application of the different methods yields fairly similar results. The neutral r...

  15. Molecular phylogeny and SNP variation of polar bears (Ursus maritimus), brown bears (U. arctos), and black bears (U. americanus) derived from genome sequences.

    Science.gov (United States)

    Cronin, Matthew A; Rincon, Gonzalo; Meredith, Robert W; MacNeil, Michael D; Islas-Trejo, Alma; Cánovas, Angela; Medrano, Juan F

    2014-01-01

    We assessed the relationships of polar bears (Ursus maritimus), brown bears (U. arctos), and black bears (U. americanus) with high throughput genomic sequencing data with an average coverage of 25× for each species. A total of 1.4 billion 100-bp paired-end reads were assembled using the polar bear and annotated giant panda (Ailuropoda melanoleuca) genome sequences as references. We identified 13.8 million single nucleotide polymorphisms (SNP) in the 3 species aligned to the polar bear genome. These data indicate that polar bears and brown bears share more SNP with each other than either does with black bears. Concatenation and coalescence-based analysis of consensus sequences of approximately 1 million base pairs of ultraconserved elements in the nuclear genome resulted in a phylogeny with black bears as the sister group to brown and polar bears, and all brown bears are in a separate clade from polar bears. Genotypes for 162 SNP loci of 336 bears from Alaska and Montana showed that the species are genetically differentiated and there is geographic population structure of brown and black bears but not polar bears.

  16. Application of large-scale parentage analysis for investigating natal dispersal in highly vagile vertebrates: a case study of American black bears (Ursus americanus).

    Science.gov (United States)

    Moore, Jennifer A; Draheim, Hope M; Etter, Dwayne; Winterstein, Scott; Scribner, Kim T

    2014-01-01

    Understanding the factors that affect dispersal is a fundamental question in ecology and conservation biology, particularly as populations are faced with increasing anthropogenic impacts. Here we collected georeferenced genetic samples (n = 2,540) from three generations of black bears (Ursus americanus) harvested in a large (47,739 km2), geographically isolated population and used parentage analysis to identify mother-offspring dyads (n = 337). We quantified the effects of sex, age, habitat type and suitability, and local harvest density at the natal and settlement sites on the probability of natal dispersal, and on dispersal distances. Dispersal was male-biased (76% of males dispersed) but a small proportion (21%) of females also dispersed, and female dispersal distances (mean ± SE  =  48.9±7.7 km) were comparable to male dispersal distances (59.0±3.2 km). Dispersal probabilities and dispersal distances were greatest for bears in areas with high habitat suitability and low harvest density. The inverse relationship between dispersal and harvest density in black bears suggests that 1) intensive harvest promotes restricted dispersal, or 2) high black bear population density decreases the propensity to disperse. Multigenerational genetic data collected over large landscape scales can be a powerful means of characterizing dispersal patterns and causal associations with demographic and landscape features in wild populations of elusive and wide-ranging species.

  17. Application of large-scale parentage analysis for investigating natal dispersal in highly vagile vertebrates: a case study of American black bears (Ursus americanus.

    Directory of Open Access Journals (Sweden)

    Jennifer A Moore

    Full Text Available Understanding the factors that affect dispersal is a fundamental question in ecology and conservation biology, particularly as populations are faced with increasing anthropogenic impacts. Here we collected georeferenced genetic samples (n = 2,540 from three generations of black bears (Ursus americanus harvested in a large (47,739 km2, geographically isolated population and used parentage analysis to identify mother-offspring dyads (n = 337. We quantified the effects of sex, age, habitat type and suitability, and local harvest density at the natal and settlement sites on the probability of natal dispersal, and on dispersal distances. Dispersal was male-biased (76% of males dispersed but a small proportion (21% of females also dispersed, and female dispersal distances (mean ± SE  =  48.9±7.7 km were comparable to male dispersal distances (59.0±3.2 km. Dispersal probabilities and dispersal distances were greatest for bears in areas with high habitat suitability and low harvest density. The inverse relationship between dispersal and harvest density in black bears suggests that 1 intensive harvest promotes restricted dispersal, or 2 high black bear population density decreases the propensity to disperse. Multigenerational genetic data collected over large landscape scales can be a powerful means of characterizing dispersal patterns and causal associations with demographic and landscape features in wild populations of elusive and wide-ranging species.

  18. Population parameters and the relationships between environmental factors and abundance of the Acetes americanus shrimp (Dendrobranchiata: Sergestidae near a coastal upwelling region of Brazil

    Directory of Open Access Journals (Sweden)

    Ana Paula Freitas dos Santos

    2015-09-01

    Full Text Available AbstractThe population dynamics of Acetes americanus was investigated, focusing on the sex ratio, individual growth, longevity, recruitment and relationship between abundance and environmental factors in the region of Macaé, strongly influenced by coastal upwelling. Otter trawl net samplings were performed from July 2010 to June 2011 at two points (5 m and 15 m. Nearly 19,500 specimens, predominantly females (77.15%, were captured. Their sizes, larger than that of males, indicated sexual dimorphism. Shrimps at lower latitudes present larger sizes and longer longevity than those from higher latitudes. This difference is probably due to low temperatures and high primary productivity. Though no statistical correlation was found between abundance and environmental factors, the species was more abundant in temperatures closer to 20.0º C and in months with high chlorophyll-a levels. Due to the peculiar characteristics of this region, A. americanusshowed greater differences in size and longevity than individuals sampled in other studies undertaken in the continental shelf of Southeast Brazil.

  19. Two crystal forms of a helix-rich fatty acid- and retinol-binding protein, Na-FAR-1, from the parasitic nematode Necator americanus

    International Nuclear Information System (INIS)

    Gabrielsen, Mads; Rey-Burusco, M. Florencia; Griffiths, Kate; Roe, Andrew J.; Cooper, Alan; Smith, Brian O.; Kennedy, Malcolm W.; Corsico, Betina

    2012-01-01

    Na-FAR-1, a fatty acid- and retinol-binding protein, was expressed in bacteria, purified and crystallized. Crystals grew in two different morphologies under the same conditions. Na-FAR-1 is an unusual α-helix-rich fatty acid- and retinol-binding protein from Necator americanus, a blood-feeding intestinal parasitic nematode of humans. It belongs to the FAR protein family, which is unique to nematodes; no structural information is available to date for FAR proteins from parasites. Crystals were obtained with two different morphologies that corresponded to different space groups. Crystal form 1 exhibited space group P432 (unit-cell parameters a = b = c = 120.80 Å, α = β = γ = 90°) and diffracted to 2.5 Å resolution, whereas crystal form 2 exhibited space group F23 (unit-cell parameters a = b = c = 240.38 Å, α = β = γ = 90°) and diffracted to 3.2 Å resolution. Crystal form 2 showed signs of significant twinning

  20. The effect of soil composition and hydration on the bioavailability and toxicity of cadmium to hibernating juvenile American toads (Bufo americanus)

    Science.gov (United States)

    James, Stacy M.; Little, Edward E.; Semlitsch, Raymond D.

    2004-01-01

    The soil ecotoxicology literature has focused primarily on a few major taxa, to the neglect of other fossorial organisms such as amphibians. We selected cadmium (Cd) and the American toad (Bufo americanus) as a model contaminant and biological species to assess the impact of soil contamination on amphibian hibernation survival and post-hibernation condition. Soil sand composition (50, 70, 90%) and hydration (100, 150% water holding capacity (WHC)) were manipulated in addition to Cd concentration (0, 56, 165, 483 μg/g) to determine whether these soil properties affect toxicity. Soil Cd concentration significantly reduced survival and locomotor performance, and was correlated negatively with percent mass loss and positively with whole body Cd concentration. Higher sand content resulted in less mass loss and greater Cd uptake. Toads that were hibernated in 50% sand hydrated to 100% WHC had higher survival, less mass loss, and better sprint performance than those hibernated in 50% sand, 150% WHC. This study demonstrates that concentrations of Cd found in soil at highly contaminated sites can be bioaccumulated by hibernating amphibians and may reduce fitness. Differences in microhabitat use may cause species to vary in their exposure and susceptibility to soil contamination. The toxicity of Cd to amphibians could be greater in natural systems where there are multiple stressors and fluctuations in environmental variables.

  1. Neutrality in mediation: an ambiguous ethical value

    OpenAIRE

    Bailey, Paul

    2014-01-01

    Mediator neutrality would appear, by definition, to be a necessary and required ethical principle for all mediators to practice. But what is meant by neutrality in mediation? Is it practically possible to be completely neutral between parties in mediation while at the same time being fair to both of them? This paper attempts to answer these two questions.

  2. Ion-beam Plasma Neutralization Interaction Images

    International Nuclear Information System (INIS)

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

    2002-04-01

    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

  3. 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.

  4. The Net Neutrality Debate: The Basics

    Science.gov (United States)

    Greenfield, Rich

    2006-01-01

    Rich Greenfield examines the basics of today's net neutrality debate that is likely to be an ongoing issue for society. Greenfield states the problems inherent in the definition of "net neutrality" used by Common Cause: "Network neutrality is the principle that Internet users should be able to access any web content they choose and…

  5. Advanced neutral-beam technology

    International Nuclear Information System (INIS)

    Berkner, K.H.

    1980-09-01

    Extensive development will be required to achieve the 50- to 75-MW, 175- to 200-keV, 5- to 10-sec pulses of deuterium atoms envisioned for ETF and INTOR. Multi-megawatt injector systems are large (and expansive); they consist of large vacuum tanks with many square meters of cryogenic pumping panels, beam dumps capable of dissipating several megawatts of un-neutralized beam, bending magnets, electrical power systems capable of fast turnoff with low (capacity) stored energy, and, of course, the injector modules (ion sources and accelerators). The technology requirements associated with these components are described

  6. Plasma neutralizers for H- or D- beams

    International Nuclear Information System (INIS)

    Berkner, K.H.; Pyle, R.V.; Savas, S.E.; Stalder, K.R.

    1980-10-01

    Plasma neutralizers can produce higher conversion efficiencies than are obtainable with gas neutralizers for the production of high-energy neutral beams from negative hydrogen ions. Little attention has been paid to experimental neutralizer studies because of the more critical problems connected with the development of negative-ion sources. With the prospect of accelerating ampere dc beams from extrapolatable ion sources some time next year, we are re-examining plasma neutralizers. Some basic considerations, two introductory experiments, and a next-step experiment are described

  7. ORNL positive ion neutral beam program

    International Nuclear Information System (INIS)

    Whealton, J.H.; Haselton, H.H.; Barber, G.C.

    1978-01-01

    The neutral beam group at Oak Ridge National Laboratory has constructed neutral beam generators for the ORMAK and PLT devices, is presently constructing neutral beam devices for the ISX and PDX devices, and is contemplating the construction of neutral beam systems for the advanced TNS device. These neutral beam devices stem from the pioneering work on ion sources of G. G. Kelley and O. B. Morgan. We describe the ion sources under development at this Laboratory, the beam optics exhibited by these sources, as well as some theoretical considerations, and finally the remainder of the beamline design

  8. 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.

  9. Three-dimensional calculations of charge neutralization by neutral gas release

    International Nuclear Information System (INIS)

    Mandell, M.J.; Jongeward, G.A.; Katz, I.

    1993-01-01

    There have been numerous observations of high rocket or spacecraft potentials, both positive and negative, and both naturally and artificially induced, being neutralized during thruster firings. Two current studies, CHARGE-2B (positive polarity) and SPEAR3 (negative polarity), attempt a more systematic exploration of this phenomenon. The authors present here calculations performed in support of the SPEAR-3 program. (1) Conventional phenomenology of breakdown is applied to the three-dimensional system formed by the electrostatic potential and plume density fields. Using real cross sections, they calculate the paths along which the nozzle plume can support breakdown. This leads to a recommendation that the higher flow rate on SPEAR-3 be 2 g/s of argon, equal to the CHARGE-2B flow rate. (2) In a laboratory chamber, conditions (pressure of ∼ 2 x 10 - 5 torr) favor breakdown of the positive (electron-collecting) sheath for SPEAR-3 geometry. Three-dimensional calculations illustrate the evolution of the space charge and potential structure during the breakdown process. These calculations demonstrate the ability to apply accepted phenomenology to real systems with three dimensional electrostatic potential fields, space charge fields, and neutral density fields, including magnetic field effects and real cross-section data

  10. Happy birthday, little neutral one

    International Nuclear Information System (INIS)

    Sutton, C.

    1990-01-01

    This article looks at the history of the neutrino particle, a tiny neutral particle which reacts only with the weak force. Its existence was originally postulated by Wolfgang Pauli in 1930, to explain beta decay energy conservation but because of the extreme experimental difficulties involved, neutrinos were not observed experimentally until 1956. Notwithstanding this the neutrino has become a valuable tool in high energy physics. Neutrino beams are used to probe matter and were used to reveal the existence of quarks within the particles once viewed as elementary, the proton and neutron. Cosmic neutrinos may be detected in the Deep Underwater Muon and Neutrino Detector off the coast of Hawaii and the Moon itself is a target for ultra high energy neutrinos in a Russian experiment to detect cascades of charge particles produced by these neutrinos in ice in the Antarctic. (UK)

  11. 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.)

  12. $\\tau$ decays with neutral kaons

    CERN Document Server

    Abbiendi, G.; Akesson, P.F.; Alexander, G.; Allison, John; Anderson, K.J.; Arcelli, S.; Asai, S.; Ashby, S.F.; Axen, D.; Azuelos, G.; Bailey, I.; Ball, A.H.; Barberio, E.; Barlow, Roger J.; Batley, J.R.; Baumann, S.; Behnke, T.; Bell, Kenneth Watson; Bella, G.; Bellerive, A.; Bentvelsen, S.; Bethke, S.; Betts, S.; Biebel, O.; Biguzzi, A.; Bloodworth, I.J.; Bock, P.; Bohme, J.; Boeriu, O.; Bonacorsi, D.; Boutemeur, M.; Braibant, S.; Bright-Thomas, P.; Brigliadori, L.; Brown, Robert M.; Burckhart, H.J.; Capiluppi, P.; Carnegie, R.K.; Carter, A.A.; Carter, J.R.; Chang, C.Y.; Charlton, David G.; Chrisman, D.; Ciocca, C.; Clarke, P.E.L.; Clay, E.; Cohen, I.; Conboy, J.E.; Cooke, O.C.; Couchman, J.; Couyoumtzelis, C.; Coxe, R.L.; Cuffiani, M.; Dado, S.; Dallavalle, G.Marco; Dallison, S.; Davis, R.; de Roeck, A.; Dervan, P.; Desch, K.; Dienes, B.; Dixit, M.S.; Donkers, M.; Dubbert, J.; Duchovni, E.; Duckeck, G.; Duerdoth, I.P.; Estabrooks, P.G.; Etzion, E.; Fabbri, F.; Fanfani, A.; Fanti, M.; Faust, A.A.; Feld, L.; Ferrari, P.; Fiedler, F.; Fierro, M.; Fleck, I.; Frey, A.; Furtjes, A.; Futyan, D.I.; Gagnon, P.; Gary, J.W.; Gaycken, G.; Geich-Gimbel, C.; Giacomelli, G.; Giacomelli, P.; Gingrich, D.M.; Glenzinski, D.; Goldberg, J.; Gorn, W.; Grandi, C.; Graham, K.; Gross, E.; Grunhaus, J.; Gruwe, M.; Hajdu, C.; Hanson, G.G.; Hansroul, M.; Hapke, M.; Harder, K.; Harel, A.; Hargrove, C.K.; Harin-Dirac, M.; Hauschild, M.; Hawkes, C.M.; Hawkings, R.; Hemingway, R.J.; Herten, G.; Heuer, R.D.; Hildreth, M.D.; Hill, J.C.; Hobson, P.R.; Hocker, James Andrew; Hoffman, Kara Dion; Homer, R.J.; Honma, A.K.; Horvath, D.; Hossain, K.R.; Howard, R.; Huntemeyer, P.; Igo-Kemenes, P.; Imrie, D.C.; Ishii, K.; Jacob, F.R.; Jawahery, A.; Jeremie, H.; Jimack, M.; Jones, C.R.; Jovanovic, P.; Junk, T.R.; Kanaya, N.; Kanzaki, J.; Karapetian, G.; Karlen, D.; Kartvelishvili, V.; Kawagoe, K.; Kawamoto, T.; Kayal, P.I.; Keeler, R.K.; Kellogg, R.G.; Kennedy, B.W.; Kim, D.H.; Klier, A.; Kobayashi, T.; Kobel, M.; Kokott, T.P.; Kolrep, M.; Komamiya, S.; Kowalewski, Robert V.; Kress, T.; Krieger, P.; von Krogh, J.; Kuhl, T.; Kupper, M.; Kyberd, P.; Lafferty, G.D.; Landsman, H.; Lanske, D.; Lauber, J.; Lawson, I.; Layter, J.G.; Lellouch, D.; Letts, J.; Levinson, L.; Liebisch, R.; Lillich, J.; List, B.; Littlewood, C.; Lloyd, A.W.; Lloyd, S.L.; Loebinger, F.K.; Long, G.D.; Losty, M.J.; Lu, J.; Ludwig, J.; Macchiolo, A.; Macpherson, A.; Mader, W.; Mannelli, M.; Marcellini, S.; Marchant, T.E.; Martin, A.J.; Martin, J.P.; Martinez, G.; Mashimo, T.; Mattig, Peter; McDonald, W.John; McKenna, J.; Mckigney, E.A.; McMahon, T.J.; McPherson, R.A.; Meijers, F.; Mendez-Lorenzo, P.; Merritt, F.S.; Mes, H.; Meyer, I.; Michelini, A.; Mihara, S.; Mikenberg, G.; Miller, D.J.; Mohr, W.; Montanari, A.; Mori, T.; Nagai, K.; Nakamura, I.; Neal, H.A.; Nisius, R.; O'Neale, S.W.; Oakham, F.G.; Odorici, F.; Ogren, H.O.; Okpara, A.; Oreglia, M.J.; Orito, S.; Pasztor, G.; Pater, J.R.; Patrick, G.N.; Patt, J.; Perez-Ochoa, R.; Petzold, S.; Pfeifenschneider, P.; Pilcher, J.E.; Pinfold, J.; Plane, David E.; Poli, B.; Polok, J.; Przybycien, M.; Quadt, A.; Rembser, C.; Rick, H.; Robins, S.A.; Rodning, N.; Roney, J.M.; Rosati, S.; Roscoe, K.; Rossi, A.M.; Rozen, Y.; Runge, K.; Runolfsson, O.; Rust, D.R.; Sachs, K.; Saeki, T.; Sahr, O.; Sang, W.M.; Sarkisian, E.K.G.; Sbarra, C.; Schaile, A.D.; Schaile, O.; Scharff-Hansen, P.; Schieck, J.; Schmitt, S.; Schoning, A.; Schroder, Matthias; Schumacher, M.; Schwick, C.; Scott, W.G.; Seuster, R.; Shears, T.G.; Shen, B.C.; Shepherd-Themistocleous, C.H.; Sherwood, P.; Siroli, G.P.; Skuja, A.; Smith, A.M.; Snow, G.A.; Sobie, R.; Soldner-Rembold, S.; Spagnolo, S.; Sproston, M.; Stahl, A.; Stephens, K.; Stoll, K.; Strom, David M.; Strohmer, R.; Surrow, B.; Talbot, S.D.; Taras, P.; Tarem, S.; Teuscher, R.; Thiergen, M.; Thomas, J.; Thomson, M.A.; Torrence, E.; Towers, S.; Trefzger, T.; Trigger, I.; Trocsanyi, Z.; Tsur, E.; Turner-Watson, M.F.; Ueda, I.; Van Kooten, Rick J.; Vannerem, P.; Verzocchi, M.; Voss, H.; Wackerle, F.; Waller, D.; Ward, C.P.; Ward, D.R.; Watkins, P.M.; Watson, A.T.; Watson, N.K.; Wells, P.S.; Wengler, T.; Wermes, N.; Wetterling, D.; White, J.S.; Wilson, G.W.; Wilson, J.A.; Wyatt, T.R.; Yamashita, S.; Zacek, V.; Zer-Zion, D.

    2000-01-01

    The branching ratio of the tau lepton to a neutral K meson is measured from a sample of approximately 200,000 tau decays recorded by the OPAL detector at centre-of-mass energies near the Z0 resonance. The measurement is based on two samples which identify one-prong tau decays with KL and KS mesons. The combined branching ratios are measured to be B(tau- -->pi- K0bar nutau) = (9.33+-0.68+-0.49)x10^-3 B(tau- -->pi- K0bar [>=1pi0] nutau) = (3.24+-0.74+-0.66)x10^-3 B(tau- -->K- K0bar [>=0pi0] nutau) = (3.30+-0.55+-0.39)x10^-3 where the first error is statistical and the second systematic.

  13. 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

    1994-12-31

    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.

  14. 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.

  15. 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

  16. Role of Ih in differentiating the dynamics of the gastric and pyloric neurons in the stomatogastric ganglion of the lobster, Homarus americanus.

    Science.gov (United States)

    Zhu, Lin; Selverston, Allen I; Ayers, Joseph

    2016-06-01

    The hyperpolarization-activated inward cationic current (Ih) is known to regulate the rhythmicity, excitability, and synaptic transmission in heart cells and many types of neurons across a variety of species, including some pyloric and gastric mill neurons in the stomatogastric ganglion (STG) in Cancer borealis and Panulirus interruptus However, little is known about the role of Ih in regulating the gastric mill dynamics and its contribution to the dynamical bifurcation of the gastric mill and pyloric networks. We investigated the role of Ih in the rhythmic activity and cellular excitability of both the gastric mill neurons (medial gastric, gastric mill) and pyloric neurons (pyloric dilator, lateral pyloric) in Homarus americanus Through testing the burst period between 5 and 50 mM CsCl, and elimination of postinhibitory rebound and voltage sag, we found that 30 mM CsCl can sufficiently block Ih in both the pyloric and gastric mill neurons. Our results show that Ih maintains the excitability of both the pyloric and gastric mill neurons. However, Ih regulates slow oscillations of the pyloric and gastric mill neurons differently. Specifically, blocking Ih diminishes the difference between the pyloric and gastric mill burst periods by increasing the pyloric burst period and decreasing the gastric mill burst period. Moreover, the phase-plane analysis shows that blocking Ih causes the trajectory of slow oscillations of the gastric mill neurons to change toward the pyloric sinusoidal-like trajectories. In addition to regulating the pyloric rhythm, we found that Ih is also essential for the gastric mill rhythms and differentially regulates these two dynamics. Copyright © 2016 the American Physiological Society.

  17. Influence of drift and admixture on population structure of American black bears (Ursus americanus) in the Central Interior Highlands, USA, 50 years after translocation.

    Science.gov (United States)

    Puckett, Emily E; Kristensen, Thea V; Wilton, Clay M; Lyda, Sara B; Noyce, Karen V; Holahan, Paula M; Leslie, David M; Beringer, Jeff; Belant, Jerrold L; White, Don; Eggert, Lori S

    2014-05-01

    Bottlenecks, founder events, and genetic drift often result in decreased genetic diversity and increased population differentiation. These events may follow abundance declines due to natural or anthropogenic perturbations, where translocations may be an effective conservation strategy to increase population size. American black bears (Ursus americanus) were nearly extirpated from the Central Interior Highlands, USA by 1920. In an effort to restore bears, 254 individuals were translocated from Minnesota, USA, and Manitoba, Canada, into the Ouachita and Ozark Mountains from 1958 to 1968. Using 15 microsatellites and mitochondrial haplotypes, we observed contemporary genetic diversity and differentiation between the source and supplemented populations. We inferred four genetic clusters: Source, Ouachitas, Ozarks, and a cluster in Missouri where no individuals were translocated. Coalescent models using approximate Bayesian computation identified an admixture model as having the highest posterior probability (0.942) over models where the translocation was unsuccessful or acted as a founder event. Nuclear genetic diversity was highest in the source (AR = 9.11) and significantly lower in the translocated populations (AR = 7.07-7.34; P = 0.004). The Missouri cluster had the lowest genetic diversity (AR = 5.48) and served as a natural experiment showing the utility of translocations to increase genetic diversity following demographic bottlenecks. Differentiation was greater between the two admixed populations than either compared to the source, suggesting that genetic drift acted strongly over the eight generations since the translocation. The Ouachitas and Missouri were previously hypothesized to be remnant lineages. We observed a pretranslocation remnant signature in Missouri but not in the Ouachitas. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  18. Six months of disuse during hibernation does not increase intracortical porosity or decrease cortical bone geometry, strength, or mineralization in black bear (Ursus americanus) femurs.

    Science.gov (United States)

    McGee-Lawrence, Meghan E; Wojda, Samantha J; Barlow, Lindsay N; Drummer, Thomas D; Bunnell, Kevin; Auger, Janene; Black, Hal L; Donahue, Seth W

    2009-07-22

    Disuse typically uncouples bone formation from resorption, leading to bone loss which compromises bone mechanical properties and increases the risk of bone fracture. Previous studies suggest that bears can prevent bone loss during long periods of disuse (hibernation), but small sample sizes have limited the conclusions that can be drawn regarding the effects of hibernation on bone structure and strength in bears. Here we quantified the effects of hibernation on structural, mineral, and mechanical properties of black bear (Ursus americanus) cortical bone by studying femurs from large groups of male and female bears (with wide age ranges) killed during pre-hibernation (fall) and post-hibernation (spring) periods. Bone properties that are affected by body mass (e.g. bone geometrical properties) tended to be larger in male compared to female bears. There were no differences (p>0.226) in bone structure, mineral content, or mechanical properties between fall and spring bears. Bone geometrical properties differed by less than 5% and bone mechanical properties differed by less than 10% between fall and spring bears. Porosity (fall: 5.5+/-2.2%; spring: 4.8+/-1.6%) and ash fraction (fall: 0.694+/-0.011; spring: 0.696+/-0.010) also showed no change (p>0.304) between seasons. Statistical power was high (>72%) for these analyses. Furthermore, bone geometrical properties and ash fraction (a measure of mineral content) increased with age and porosity decreased with age. These results support the idea that bears possess a biological mechanism to prevent disuse and age-related osteoporoses.

  19. Isolation and Genetic Characterization of Toxoplasma gondii from Black Bears (Ursus americanus), Bobcats (Lynx rufus), and Feral Cats (Felis catus) from Pennsylvania.

    Science.gov (United States)

    Dubey, Jitender P; Verma, Shiv K; Calero-Bernal, Rafael; Cassinelli, Ana B; Kwok, Oliver C H; Van Why, Kyle; Su, Chunlei; Humphreys, Jan G

    2015-01-01

    Toxoplasma gondii infects virtually all warm-blooded hosts worldwide. Recently, attention has been focused on the genetic diversity of the parasite to explain its pathogenicity in different hosts. It has been hypothesized that interaction between feral and domestic cycles of T. gondii may increase unusual genotypes in domestic cats and facilitate transmission of potentially more pathogenic genotypes to humans, domestic animals, and wildlife. In the present study, we tested black bear (Ursus americanus), bobcat (Lynx rufus), and feral cat (Felis catus) from the state of Pennsylvania for T. gondii infection. Antibodies to T. gondii were found in 32 (84.2%) of 38 bears, both bobcats, and 2 of 3 feral cats tested by the modified agglutination test (cut off titer 1:25). Hearts from seropositive animals were bioassayed in mice, and viable T. gondii was isolated from 3 of 32 bears, 2 of 2 bobcats, and 2 of 3 feral cats. DNA isolated from culture-derived tachyzoites of these isolates was characterized using multilocus PCR-RFLP markers. Three genotypes were revealed, including ToxoDB PCR-RFLP genotype #1 or #3 (Type II, 1 isolate), #5 (Type 12, 3 isolates), and #216 (3 isolates), adding to the evidence of genetic diversity of T. gondii in wildlife in Pennsylvania. Pathogenicity of 3 T. gondii isolates (all #216, 1 from bear, and 2 from feral cat) was determined in outbred Swiss Webster mice; all three were virulent causing 100% mortality. Results indicated that highly mouse pathogenic strains of T. gondii are circulating in wildlife, and these strains may pose risk to infect human through consuming of game meat. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  20. Substrate-Driven Convergence of the Microbial Community in Lignocellulose-Amended Enrichments of Gut Microflora from the Canadian Beaver (Castor canadensis) and North American Moose (Alces americanus).

    Science.gov (United States)

    Wong, Mabel T; Wang, Weijun; Lacourt, Michael; Couturier, Marie; Edwards, Elizabeth A; Master, Emma R

    2016-01-01

    Strategic enrichment of microcosms derived from wood foragers can facilitate the discovery of key microbes that produce enzymes for the bioconversion of plant fiber (i.e., lignocellulose) into valuable chemicals and energy. In this study, lignocellulose-degrading microorganisms from the digestive systems of Canadian beaver (Castor canadensis) and North American moose (Alces americanus) were enriched under methanogenic conditions for over 3 years using various wood-derived substrates, including (i) cellulose (C), (ii) cellulose + lignosulphonate (CL), (iii) cellulose + tannic acid (CT), and (iv) poplar hydrolysate (PH). Substantial improvement in the conversion of amended organic substrates into biogas was observed in both beaver dropping and moose rumen enrichment cultures over the enrichment phases (up to 0.36-0.68 ml biogas/mg COD added), except for enrichments amended with tannic acid where conversion was approximately 0.15 ml biogas/mg COD added. Multiplex-pyrosequencing of 16S rRNA genes revealed systematic shifts in the population of Firmicutes, Bacteroidetes, Chlorobi, Spirochaetes, Chloroflexi, and Elusimicrobia in response to the enrichment. These shifts were predominantly substrate driven, not inoculum driven, as revealed by both UPGMA clustering pattern and OTU distribution. Additionally, the relative abundance of multiple OTUs from poorly defined taxonomic lineages increased from less than 1% to 25-50% in microcosms amended with lignocellulosic substrates, including OTUs from classes SJA-28, Endomicrobia, orders Bacteroidales, OPB54, and family Lachnospiraceae. This study provides the first direct comparison of shifts in microbial communities that occurred in different environmental samples in response to multiple relevant lignocellulosic carbon sources, and demonstrates the potential of enrichment to increase the abundance of key lignocellulolytic microorganisms and encoded activities.

  1. Discovery and description of a new trichostrongyloid species (Nematoda: Ostertagiinae), abomasal parasites in mountain goat, Oreamnos americanus, from the Western Cordillera of North America.

    Science.gov (United States)

    Hoberg, Eric P; Abrams, Arthur; Pilitt, Patricia A; Jenkins, Emily J

    2012-08-01

    Marshallagia lichtenfelsi sp. n. is a dimorphic ostertagiine nematode occurring in the abomasum of mountain goats, Oreamnos americanus, from the Western Cordillera of North America. Major and minor morphotype males and females are characterized and distinguished relative to the morphologically similar Marshallagia marshalli / Marshallagia occidentalis from North America and Marshallagia dentispicularis, along with other congeners, from the Palearctic region. The configuration of the convoluted and irregular synlophe in the cervical region of males and females of M. lichtenfelsi is apparently unique, contrasting with a continuous and parallel system of ridges among those species of Marshallagia, including M. marshalli/M. occidentalis, which have been evaluated. Specimens of M. lichtenfelsi are further defined by the rectangular form of the accessory bursal membrane (width > length) in the major morphotype and by the trapezoidal Sjöberg's organ in the minor morphotype, in addition to specific attributes of the spicules and spicule tips. We regard 12 species, including the proposed new taxon, to be valid. Primary diagnostic characters are reviewed for Marshallagia and a framework is presented for standardization of future descriptions incorporating the synlophe in males and females and the structure of the spicules and genital cone in major and minor morphotype males. The center of diversity for species of Marshallagia is the mountain-steppe region of central Eurasia where 11 species (including the Holarctic M. marshalli) are recognized in association with Caprini, Rupicaprini, and Antelopinae; only 2 species occur in the Nearctic. In this assemblage, M. lichtenfelsi is endemic to North America and limited in host distribution to mountain goats. An intricate history for refugial isolation and population fragmentation demonstrated for mountain goats and wild sheep indicates the potential for considerable cryptic diversity for Marshallagia and other nematodes. Shifting

  2. Incidence of Infestation and Larval Success of Emerald Ash Borer (Agrilus planipennis) on White Fringetree (Chionanthus virginicus), Chinese Fringetree (Chionanthus retusus), and Devilwood (Osmanthus americanus).

    Science.gov (United States)

    Cipollini, Don; Rigsby, Chad M

    2015-10-01

    We compared the incidence of infestation by emerald ash borer (EAB) and lilac borer on white fringetree to that of its Asian congener, Chinese fringetree, Chionanthus retusus, and a North American relative, devilwood, Osmanthus americanus. We also conducted laboratory bioassays to determine the suitability of these hosts for EAB larvae. At Spring Grove Cemetery and Arboretum in Cincinnati, Ohio, 9 of 28 white fringetrees examined were infested by EAB. Most of the white fringetrees had lilac borer infestation, and most of the trees infested by EAB also had lilac borer infestation. None of the 11 Chinese fringetrees examined were infested by either EAB or lilac borer. Each of the five devilwood individuals examined was infested by lilac borer, but not EAB. At The Morton Arboretum in Lisle, Illinois, 7 of 16 white fringetrees examined were infested by EAB, while none of the seven Chinese fringetrees examined were infested by either insect. A 40-d bioassay confirmed that white fringetree was an acceptable host, producing fourth-instar larvae that were smaller than those produced on a highly susceptible cultivar of green ash, Fraxinus pennsylvanica. No larvae survived on Chinese fringetree, and neonates were largely incapable of feeding on it. Two larvae survived on devilwood, reaching the second instar and excavating extensive galleries. Future work should be aimed at biotic and abiotic factors influencing the susceptibility of white fringetree, as well as further examination of close relatives for their vulnerability to EAB. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  3. Construction of a subtractive library from hexavalent chromium treated winter flounder (Pseudopleuronectes americanus) reveals alterations in non-selenium glutathione peroxidases

    International Nuclear Information System (INIS)

    Chapman, Laura M.; Roling, Jonathan A.; Bingham, Lacey K.; Herald, Matt R.; Baldwin, William S.

    2004-01-01

    Chromium is released during several industrial processes and has accumulated in some estuarine areas. Its effects on mammals have been widely studied, but relatively little information is available on its effects on fish. Gene expression changes are useful biomarkers that can provide information about toxicant exposure and effects, as well as the health of an organism and its ability to adapt to its surroundings. Therefore, we investigated the effects of Cr(VI) on gene expression in the sediment dwelling fish, winter flounder (Pseudopleuronectes americanus). Winter flounder ranging from 300 to 360 g were injected i.p. with Cr(VI) as chromium oxide at 25 μg/kg chromium in 0.15N KCl. Twenty-four hours following injections, winter flounder were euthanized with MS-222 and the livers were excised. Half of the livers were used to make cytosol and the other half were used to isolate mRNA for subtractive hybridization. Subtractive clones obtained were spotted onto nylon filters, which revealed several genes with potentially altered expression due to Cr(VI), including an α class GST, 1-Cys peroxiredoxin (a non-selenium glutathione peroxidase), a P-450 2X subfamily member, two elongation factors (EF-1 gamma and EF-2), and complement component C3. Semi-quantitative RT-PCR was performed and confirmed that Cr(VI) down-regulated complement component C3, an EST, and two potential glutathione peroxidases, GSTA3 and 1-Cys peroxiredoxin. In addition, cytosolic GSH peroxidase activity was reduced, and silver stained SDS-PAGE gels from glutathione-affinity purified cytosol demonstrated that a 27.1 kDa GSH-binding protein was down-regulated greater than 50%. Taken together, Cr(VI) significantly altered the expression of several genes including two potential glutathione peroxidases in winter flounder

  4. 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)

  5. Molecular clock on a neutral network.

    Science.gov (United States)

    Raval, Alpan

    2007-09-28

    The number of fixed mutations accumulated in an evolving population often displays a variance that is significantly larger than the mean (the overdispersed molecular clock). By examining a generic evolutionary process on a neutral network of high-fitness genotypes, we establish a formalism for computing all cumulants of the full probability distribution of accumulated mutations in terms of graph properties of the neutral network, and use the formalism to prove overdispersion of the molecular clock. We further show that significant overdispersion arises naturally in evolution when the neutral network is highly sparse, exhibits large global fluctuations in neutrality, and small local fluctuations in neutrality. The results are also relevant for elucidating aspects of neutral network topology from empirical measurements of the substitution process.

  6. Neutral particle beam alternative concept for ITER

    International Nuclear Information System (INIS)

    Sedgley, D.; Brook, J.; Luzzi, T.; Deutsch, L.

    1989-01-01

    An analysis of an ITER neutral particle beam system is presented. The analysis covers the neutralizer, ion dumps, pumping, and geometric aspects. The US beam concept for ITER consists of three or four clusters of beamlines delivering approximately 80 MW total of 1.6-MeV deuterium to three or four reactor ports. Each cluster has three self-contained beamlines featuring plasma neutralizers and electrostatic ion dumps. In this study, each of the beamlines has two source assemblies with separate gas neutralizers and magnetic ion dumps. Deuterium is injected into the gas neutralizers by a separate system. Saddle-shaped copper coils augment the tokamak poloidal field to turn the charged particles into the ion dumps. The gas flow from the source, neutralizer, and ion dump is pumped by regenerable cryopanels. The effect of the port between the TF coils and the beam injection angle on the plasma footprint was studied

  7. 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.

  8. 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.

  9. Neutral-beam current drive in tokamaks

    International Nuclear Information System (INIS)

    Devoto, R.S.

    1986-01-01

    The theory of neutral-beam current drive in tokamaks is reviewed. Experiments are discussed where neutral beams have been used to drive current directly and also indirectly through neoclassical effects. Application of the theory to an experimental test reactor is described. It is shown that neutral beams formed from negative ions accelerated to 500 to 700 keV are needed for this device

  10. Neutral-beam current drive in tokamaks

    International Nuclear Information System (INIS)

    Devoto, R.S.

    1987-01-01

    The theory of neutral-beam current drive in tokamaks is reviewed. Experiments are discussed where neutral beams have been used to drive current directly and also indirectly through neoclassical effects. Application of the theory to an experimental test reactor is described. It is shown that neutral beams formed from negative ions accelerated to 500-700 keV are needed for this device

  11. Evidence of feasible hardness test on Mars using ratio of ionic/neutral emission intensities measured with laser-induced breakdown spectroscopy in low pressure CO_2 ambient gas

    International Nuclear Information System (INIS)

    Abdulmadjid, Syahrun Nur; Lahna, Kurnia; Idris, Nasrullah; Pardede, Marincan; Suyanto, Hery; Ramli, Muliadi; Marpaung, Alion Mangasi; Hedwig, Rinda; Lie, Zener Sukra; Kurniawan, Davy Putra; Kurniawan, Koo Hendrik; Lie, Tjung Jie; Tjia, May On; Kagawa, Kiichiro

    2016-01-01

    An experimental study is conducted on the possibility and viability of performing hardness measurement of the various stone and chert samples in low pressure (600 Pa) CO_2 ambient gas, a condition that is encountered in the Mars atmosphere. For this study, a nanosecond Nd-YAG laser is employed to generate plasma emission from the samples with different degrees of hardness. This technique is developed in light of the role of the shock wave in the generation of a laser-induced plasma. It was previously shown that the speed of the shock front depends on the hardness of the sample, and a positive relationship was found between the speed of the shock front and the ionization rate of the ablated atoms. Hence, the ratio of the intensity between the Mg II 279.5 nm and Mg I 285.2 nm emission lines detected from the laser-induced plasma can be used to estimate the hardness of a material. In fact, it is shown that the ratio changes linearly with respect to changes of sample hardness. The result has thus demonstrated the feasibility and viability of using LIBS for non contact hardness measurement on Mars.

  12. Evidence of feasible hardness test on Mars using ratio of ionic/neutral emission intensities measured with laser-induced breakdown spectroscopy in low pressure CO{sub 2} ambient gas

    Energy Technology Data Exchange (ETDEWEB)

    Abdulmadjid, Syahrun Nur; Lahna, Kurnia; Idris, Nasrullah [Department of Physics, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh 23111, NAD (Indonesia); Pardede, Marincan [Department of Electrical Engineering, University of Pelita Harapan, 1100 M.H. Thamrin Boulevard, Lippo Village, Tangerang 15811 (Indonesia); Suyanto, Hery [Department of Physics, Faculty of Mathematics and Natural Sciences, Udayana University, Kampus Bukit Jimbaran, Denpasar 80361, Bali (Indonesia); Ramli, Muliadi [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Syiah Kuala University, Darussalam, Banda Aceh 23111, NAD (Indonesia); Marpaung, Alion Mangasi [Department of Physics, Faculty of Mathematics and Natural Sciences, Jakarta State University, 10 Rawamangun, Jakarta 13220 (Indonesia); Hedwig, Rinda [Department of Computer Engineering, Bina Nusantara University, 9 K.H. Syahdan, Jakarta 14810 (Indonesia); Lie, Zener Sukra [Department of Computer Engineering, Bina Nusantara University, 9 K.H. Syahdan, Jakarta 14810 (Indonesia); Research Center of Maju Makmur Mandiri Foundation, 40/80 Srengseng Raya, Jakarta 11630 (Indonesia); Kurniawan, Davy Putra; Kurniawan, Koo Hendrik, E-mail: kurnia18@cbn.net.id; Lie, Tjung Jie [Research Center of Maju Makmur Mandiri Foundation, 40/80 Srengseng Raya, Jakarta 11630 (Indonesia); Tjia, May On [Research Center of Maju Makmur Mandiri Foundation, 40/80 Srengseng Raya, Jakarta 11630 (Indonesia); Physics of Magnetism and Photonics Group, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, 10 Ganesha, Bandung 40132 (Indonesia); Kagawa, Kiichiro [Research Center of Maju Makmur Mandiri Foundation, 40/80 Srengseng Raya, Jakarta 11630 (Indonesia); Fukui Science Education Academy, Takagi Chuo 2 chome, Fukui 910-0804 (Japan)

    2016-04-28

    An experimental study is conducted on the possibility and viability of performing hardness measurement of the various stone and chert samples in low pressure (600 Pa) CO{sub 2} ambient gas, a condition that is encountered in the Mars atmosphere. For this study, a nanosecond Nd-YAG laser is employed to generate plasma emission from the samples with different degrees of hardness. This technique is developed in light of the role of the shock wave in the generation of a laser-induced plasma. It was previously shown that the speed of the shock front depends on the hardness of the sample, and a positive relationship was found between the speed of the shock front and the ionization rate of the ablated atoms. Hence, the ratio of the intensity between the Mg II 279.5 nm and Mg I 285.2 nm emission lines detected from the laser-induced plasma can be used to estimate the hardness of a material. In fact, it is shown that the ratio changes linearly with respect to changes of sample hardness. The result has thus demonstrated the feasibility and viability of using LIBS for non contact hardness measurement on Mars.

  13. 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.

  14. Structural Basis for Differential Neutralization of Ebolaviruses

    Directory of Open Access Journals (Sweden)

    John M. Dye

    2012-04-01

    Full Text Available There are five antigenically distinct ebolaviruses that cause hemorrhagic fever in humans or non-human primates (Ebola virus, Sudan virus, Reston virus, Taï Forest virus, and Bundibugyo virus. The small handful of antibodies known to neutralize the ebolaviruses bind to the surface glycoprotein termed GP1,2. Curiously, some antibodies against them are known to neutralize in vitro but not protect in vivo, whereas other antibodies are known to protect animal models in vivo, but not neutralize in vitro. A detailed understanding of what constitutes a neutralizing and/or protective antibody response is critical for development of novel therapeutic strategies. Here, we show that paradoxically, a lower affinity antibody with restricted access to its epitope confers better neutralization than a higher affinity antibody against a similar epitope, suggesting that either subtle differences in epitope, or different characteristics of the GP1,2 molecules themselves, confer differential neutralization susceptibility. Here, we also report the crystal structure of trimeric, prefusion GP1,2 from the original 1976 Boniface variant of Sudan virus complexed with 16F6, the first antibody known to neutralize Sudan virus, and compare the structure to that of Sudan virus, variant Gulu. We discuss new structural details of the GP1-GP2 clamp, thermal motion of various regions in GP1,2 across the two viruses visualized, details of differential interaction of the crystallized neutralizing antibodies, and their relevance for virus neutralization.

  15. Hexon and fiber of adenovirus type 14 and 55 are major targets of neutralizing antibody but only fiber-specific antibody contributes to cross-neutralizing activity.

    Science.gov (United States)

    Feng, Ying; Sun, Xikui; Ye, Xianmiao; Feng, Yupeng; Wang, Jinlin; Zheng, Xuehua; Liu, Xinglong; Yi, Changhua; Hao, Mingli; Wang, Qian; Li, Feng; Xu, Wei; Li, Liang; Li, Chufang; Zhou, Rong; Chen, Ling; Feng, Liqiang

    2018-05-01

    Re-emerging human adenoviruses type 14 (HAdV14) and 55 (HAdV55) represent two highly virulent adenoviruses. The neutralizing antibody (nAb) responses elicited by infection or immunization remain largely unknown. Herein, we generated hexon-chimeric HAdV14 viruses harboring each single or entire hexon hyper-variable-regions (HVR) from HAdV55, and determined the neutralizing epitopes of human and mouse nAbs. In human sera, hexon-targeting nAbs are type-specific and mainly recognize HVR2, 5, and 7. Fiber-targeting nAbs are only detectable in sera cross-neutralizing HAdV14 and HAdV55 and contribute substantially to cross-neutralization. Penton-binding antibodies, however, show no significant neutralizing activities. In mice immunized with HAdV14 or HAdV55, a single immunization mainly elicited hexon-specific nAbs, which recognized HAdV14 HVR1, 2, and 7 and HAdV55 HVR1 and 2, respectively. After a booster immunization, cross-neutralizing fiber-specific nAbs became detectable. These results indicated that hexon elicits type-specific nAbs whereas fiber induces cross-neutralizing nAbs to HAdV14 and HAdV55, which are of significance in vaccine development. Copyright © 2018 Elsevier Inc. All rights reserved.

  16. 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

  17. Evidence for neutral neutrino current coupling to right-handed quarks

    International Nuclear Information System (INIS)

    Allaby, J.V.; Amaldi, U.; Barbiellini, G.; Baubillier, M.; Bergsma, F.; Capone, A.; Flegel, W.; Lanceri, L.; Metcalf, M.; Nieuwenhuis, C.; Pain, R.; Panman, J.; Winter, K.; Abt, I.; Blobel, V.; Buengener, A.; Buesser, F.W.; Gall, P.D.; Hebbeker, T.; Niebergall, F.; Staehelin, P.; Borgia, B.; Diemoz, M.; Dionisi, C.; Dore, U.; Ferroni, F.; Longo, E.; Loverre, P.F.; Luminari, L.; Monacelli, P.; Morganti, S.; De Notaristefani, F.; Santacesaria, R.; Santoni, C.; Rome-1 Univ.

    1989-01-01

    Differential cross sections dσ/dy have been measured in semileptonic neutral- and charged-current reactions induced by neutrinos and antineutrinos. The comparison of the neutral- and the charged-current differential cross sections allows the direct determination of the chiral coupling of the neutral (νanti ν) current to left- and right-handed quarks. The result, with a value of g R 2 =0.042±0.010, is the first direct determination, with a significance of more than four standard deviations, of a non-zero value of g R . (orig.)

  18. Evidence for biofilm acid neutralization by baking soda.

    Science.gov (United States)

    Zero, Domenick T

    2017-11-01

    The generating of acids from the microbial metabolism of dietary sugars and the subsequent decrease in biofilm pH below the pH at which tooth mineral begins to demineralize (critical pH) are the key elements of the dental caries process. Caries preventive strategies that rapidly neutralize biofilm acids can prevent demineralization and favor remineralization and may help prevent the development of sugar-induced dysbiosis that shifts the biofilm toward increased cariogenic potential. Although the neutralizing ability of sodium bicarbonate (baking soda) has been known for many years, its anticaries potential as an additive to fluoride dentifrice has received only limited investigation. There is evidence that baking soda rapidly can reverse the biofilm pH decrease after a sugar challenge; however, the timing of when it is used in relation to a dietary sugar exposure is critical in that the sooner its used the greater the benefit in preventing a sustained biofilm pH decrease and subsequent demineralization. Furthermore, the effectiveness of baking soda in elevating biofilm pH appears to depend on concentration. Thus, the concentration of baking soda in marketed dentifrice products, which ranges from 10% to 65%, may affect their biofilm pH neutralizing performance. People with hyposalivation particularly may benefit from using fluoride dentifrice containing baking soda because of their diminished ability to clear dietary sugars and buffer biofilm acids. Although promising, there is the need for more evidence that strategies that modify the oral ecology, such as baking soda, can alter the cariogenic (acidogenic and aciduric) properties of biofilm microorganisms. The acid neutralization of dental biofilm by using fluoride dentifrice that contains baking soda has potential for helping counteract modern high-sugar diets by rapidly neutralizing biofilm-generated acid, especially in people with hyposalivation. Copyright © 2017 American Dental Association. Published by

  19. Neutral iron densities in front of a reference limiter in TEXTOR

    International Nuclear Information System (INIS)

    Schweer, B.; Bay, H.L.

    1983-09-01

    Preliminary measurements of the time and space resolved densities of neutral iron in front of a reference limiter in Textor have been performed using laser induced fluorescence. The limiter was made of stainless steel (SS 316) and formed as a half sphere, 10 cm in diameter. Neutral iron densities up to 5 x 10 9 atoms/cm 3 were found. The detection limit was below 10 7 atoms/cm 3 . (orig.)

  20. The status of neutral currents

    International Nuclear Information System (INIS)

    Zwirner, F.

    1987-11-01

    The situation of particle physics today is quite puzzling. On the one hand, the Standard Model (SM) of strong and electroweak interactions is consistent with all confirmed experimental data but theoretically rather unsatisfactory. On the other hand, none of the many theoretical speculations which try to go beyond the SM has (yet) received the slightest experimental support. The solution to this dilemma can only come from new data: either from the detection of a new particle threshold at high energy colliders, or from the appearance of some small discrepancy in high-precision experiments. A crucial sector for testing the SM and its extensions is that of neutral currents (NC), where an impressive amount of data has been collected in recent years. While waiting for the next generation of experiments, it is certainly useful to take stock of our knowledge, determining the NC parameters as precisely as we can and putting limits on possible deviations from the SM. The present talk contains the results of a recent analysis along these lines: the first part illustrates how a set of 'model-independent' parameters can be extracted from the available NC data, the second part particularizes the analysis to the SM and to some superstring-inspired models with an additional Z' in their low-energy spectrum. 27 refs., 3 figs., 1 tab

  1. Impact of host cell variation on the neutralization of HIV-1 in vitro.

    Science.gov (United States)

    Polonis, Victoria R; Schuitemaker, Hanneke; Bunnik, Evelien M; Brown, Bruce K; Scarlatti, Gabriella

    2009-09-01

    In this review we present current advances in our understanding of HIV-1 neutralization assays that employ primary cell types, as compared with those that utilize cell lines and the newer, more standardized pseudovirus assays. A commentary on the challenges of standardizing in-vitro neutralization assays using primary cells is included. The data from reporter cell line neutralization assays may agree with results observed in primary cells; however, exceptions have recently been reported. Multiple variables exist in primary cell assays using peripheral blood mononuclear cells from HIV-seronegative donors; in-vitro neutralization titers can vary significantly based on the donor cells used for assay targets and for virus propagation. Thus, more research is required to achieve validated primary cell neutralization assays. HIV-vaccine-induced antibody performance in the current neutralization assays may function as a 'gatekeeper' for HIV-1 subunit vaccine advancement. Development of standardized platforms for reproducible measurement of in-vitro neutralization is therefore a high priority. Given the considerable variation in results obtained from some widely applied HIV neutralization platforms, parallel evaluation of new antibodies using different host cells for assay targets, as well as virus propagation, is recommended until immune correlates of protection are identified.

  2. Effect of Thermospheric Neutral Density upon Inner Trapped-belt Proton Flux

    Science.gov (United States)

    Wilson, Thomas L.; Lodhi, M. A. K.; Diaz, Abel B.

    2007-01-01

    We wish to point out that a secular change in the Earth's atmospheric neutral density alters charged-particle lifetime in the inner trapped radiation belts, in addition to the changes recently reported as produced by greenhouse gases. Heretofore, changes in neutral density have been of interest primarily because of their effect on the orbital drag of satellites. We extend this to include the orbital lifetime of charged particles in the lower radiation belts. It is known that the charged-belt population is coupled to the neutral density of the atmosphere through changes induced by solar activity, an effect produced by multiple scattering off neutral and ionized atoms along with ionization loss in the thermosphere where charged and neutral populations interact. It will be shown here that trapped-belt flux J is bivariant in energy E and thermospheric neutral density , as J(E,rho). One can conclude that proton lifetimes in these belts are also directly affected by secular changes in the neutral species populating the Earth s thermosphere. This result is a consequence of an intrinsic property of charged-particle flux, that flux is not merely a function of E but is dependent upon density rho when a background of neutrals is present.

  3. 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

  4. 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...

  5. 3He neutral current detectors at SNO

    International Nuclear Information System (INIS)

    Elliott, S.R.; Browne, M.C.; Doe, P.J.

    1998-01-01

    The flux of solar neutrinos measured via charged and neutral current interactions can provide a model independent test of neutrino oscillations. Since the Sudbury Neutrino Observatory uses heavy water as a target, it has a large sensitivity to both interactions. A technique for observing the neutral current breakup of the deuteron using 3 He proportional counters is described

  6. 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

  7. On the possible eigenoscillations of neutral sheets

    International Nuclear Information System (INIS)

    Almeida, W.A.; Costa, J.M. da; Aruquipa, E.G.; Sudano, J.P.

    1974-12-01

    A neutral sheet model with hyperbolic tangent equilibrium magnetic field and hyperbolic square secant density profiles is considered. It is shown that the equation for small oscillations takes the form of an eigenvalue oscillation problem. Computed eigenfrequencies of the geomagnetic neutral sheet were found to be in the range of the resonant frequencies of the geomagnetic plasma sheet computed by other authors

  8. Gender Neutrality: Women's Friend or Foe?

    Science.gov (United States)

    Steuernagel, Trudy

    Gender neutral public policies are those that are either silent on the question of the existence of significant gender differences or incorporate a perspective which mandates that such differences be ignored. Prominent voices today contend that gender neutrality favors males and have held the male standard as the one for which women should aspire.…

  9. 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

  10. On plasma-neutral gas interaction

    International Nuclear Information System (INIS)

    Venkataramani, N.; Mattoo, S.K.

    1980-01-01

    The importance of plasma-neutral gas interaction layer has been emphasized by pointing out its application to a wide variety of physical phenomena. The interaction of a magnetised plasma stream penetrating a neutral gas cloud is discussed in the light of Alfven's critical velocity and Varma's threshold velocity on the ionising interaction. Interaction of a moving magnetised plasma with a stationary neutral gas has been studied and described. The device comprises of a plasma gun and an interaction region where neutral gas cloud is injected. The interaction region is provided with a transverse magnetic field of upto 1000 G. Several diagnostics deployed at the interaction region to make measurements on the macroscopic parameters of plasma and neutral gas are described. The parameters of discharge circuits are measured with high current and voltage probes. An interaction between a magnetised plasma stream and a neutral gas cloud is demonstrated. It is shown that this interaction does not have Varma's threshold on their relative velocity. The Alfven's critical velocity phenomenon is shown to depend on the integrated column neutral gas density that a plasma stream encounters while penetrating through it and not on the neutral gas density in the range of 10 17 -10 21 m -3 . (auth.)

  11. Net Neutrality and Inflation of Traffic

    NARCIS (Netherlands)

    Peitz, M.; Schütt, F.

    2015-01-01

    Under strict net neutrality Internet service providers (ISPs) are required to carry data without any differentiation and at no cost to the content provider. We provide a simple framework with a monopoly ISP to evaluate different net neutrality rules. Content differs in its sensitivity to delay.

  12. Net neutrality and inflation of traffic

    NARCIS (Netherlands)

    Peitz, M.; Schütt, Florian

    Under strict net neutrality Internet service providers (ISPs) are required to carry data without any differentiation and at no cost to the content provider. We provide a simple framework with a monopoly ISP to evaluate the short-run effects of different net neutrality rules. Content differs in its

  13. 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

  14. 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

  15. 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

  16. Neutral beam in ALVAND IIC tokamak

    International Nuclear Information System (INIS)

    Ghrannevisse, M.; Moradshahi, M.; Avakian, M.

    1992-01-01

    Neutral beams have a wide application in tokamak experiments. It used to heat; fuel; adjust electric potentials in plasmas and diagnose particles densities and momentum distributions. It may be used to sustain currents in tokamaks to extend the pulse length. A 5 KV; 500 mA ion source has been constructed by plasma physics group, AEOI and it used to produce plasma and study the plasma parameters. Recently this ion source has been neutralized and it adapted to a neutral beam source; and it used to heat a cylindrical DC plasma and the plasma of ALVAND IIC Tokamak which is a small research tokamak with a minor radius of 12.6 cm, and a major radius of 45.5 cm. In this paper we report the neutralization of the ion beam and the results obtained by injection of this neutral beam into plasmas. (author) 2 refs., 4 figs

  17. 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.

  18. Sputtering of neutral and ionic indium clusters

    International Nuclear Information System (INIS)

    Ma, Z.; Coon, S.R.; Calaway, W.F.; Pellin, M.J.; Gruen, D.M.; Von Nagy-Felsobuki, E.I.

    1993-01-01

    Secondary neutral and secondary ion cluster yields were measured during the sputtering of a polycrystalline indium surface by normally incident ∼4 keV Ar + ions. In the secondary neutral mass spectra, indium clusters as large as In 32 were observed. In the secondary ion mass spectra, indium clusters up to In 18 + were recorded. Cluster yields obtained from both the neutral and ion channel exhibited a power law dependence on the number of constituent atoms, n, in the cluster, with the exponents measured to be -5.6 and -4. 1, respectively. An abundance drop was observed at n=8, 15, and 16 in both the neutral and ion yield distributions suggesting that the stability of the ion (either secondary ion or photoion) plays a significant role in the observed distributions. In addition, our experiments suggest that unimolecular decomposition of the neutral cluster may also plays an important role in the measured yield distributions

  19. 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

  20. ORNL neutral-beam program in 1978

    International Nuclear Information System (INIS)

    Whealton, J.H.

    1982-12-01

    This report was presented at the ion source workshop held at Culham Laboratory, Abingdon, Oxfordshire, in 1978. Because the proceedings of that conference are unavailable, and because the material in this report is still not to be found elsewhere, it is issued as a laboratory report. The neutral beam group at Oak Ridge National Laboratory has constructed neutral beam generators for the ORMAK and PLT devices, is presently constructing neutral beam devices for the ISX and PDX devices, and is contemplating the construction of neutral beam systems for the advanced TNS device. These neutral beam devices stem from the pioneering work on ion sources of G.G. Kelley and O.B. Morgan. We describe the ion sources under development at this laboratory, the beam optics exhibited by these sources, as well as some theoretical considerations, and finally the remainder of the beamline design

  1. 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.

  2. Fragmentation of neutral van der Waals clusters with visible laser light: A new variant of the Raman effect?

    International Nuclear Information System (INIS)

    Stamatovic, A.; Howorka, F.; Scheier, P.; Maerk, T.D.

    1989-01-01

    We have observed strong photodissociation (using visible laser light) of neutral van der Waals clusters (Ar, N 2 , O 2 , CO 2 , SO 2 , NH 3 ) produced by supersonic expansion and detected by electron ionization/mass spectrometer. Several tests were performed, all of them supporting this surprising discovery. We suggest that Raman induced photodissociation (RIP) is responsible for this phenomenon. This first observation of Raman induced photodissociation provides a new technique for the study of neutral van der Waals clusters. (orig.)

  3. 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

  4. 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

  5. Soviet exoatmospheric neutral particle beam research

    International Nuclear Information System (INIS)

    Leiss, J.E.; Abrams, R.H.; Ehlers, K.W.; Farrell, J.A.; Gillespie, G.H.; Jameson, R.A.; Keefe, D.; Parker, R.K.

    1988-02-01

    This technical assessment was performed by a panel of eight U.S. scientists and engineers who are familiar with Soviet research through their own research experience, their knowledge of the published scientific literature and conference proceedings, and personal contacts with Soviet scientists and other foreign colleagues. Most of the technical components of a neutral particle beam generating system including the ion source, the accelerator, the accelerator radio frequency power supply, the beam conditioning and aiming system, and the beam neutralizer system are addressed. It does not address a number of other areas important to an exoatmospheric neutral beam system

  6. Fast Neutral Pressure Measurements in NSTX

    International Nuclear Information System (INIS)

    R. Raman; H.W. Kugel; T. Provost; R. Gernhardt; T.R. Jarboe; M.G. Bell

    2002-01-01

    Several fast neutral pressure gauges have been installed on NSTX [National Spherical Torus Experiment] to measure the vessel and divertor pressure during inductive and coaxial helicity injected (CHI) plasma operations. Modified, PDX [Poloidal Divertor Experiment]-type Penning gauges have been installed on the upper and lower divertors. Neutral pressure measurements during plasma operations from these and from two shielded fast Micro ion gauges at different toroidal locations on the vessel mid-plane are described. A new unshielded ion gauge, referred to as the In-vessel Neutral Pressure (INP) gauge is under development

  7. Negative ion formation and neutralization processes, (2)

    International Nuclear Information System (INIS)

    Sugiura, Toshio

    1982-09-01

    This review is 2nd part of the report published at January 1982 (JAERI-M-9902). A compilation includes the survey of the data of the cross sections of H - and D - ion formations and the neutralization of these ions. This is also presented new information about the photosensitization by laser beam in dissociative-resonance electron capture of sulfur hexafluoride reported by Chen et al., for reference to enhancement of D - ions in discharge. For neutralization, the data of mutual neutralization and photodetachment are also presented. (author)

  8. Toxins not neutralized by brown snake antivenom

    International Nuclear Information System (INIS)

    Judge, Roopwant K.; Henry, Peter J.; Mirtschin, Peter; Jelinek, George; Wilce, Jacqueline A.

    2006-01-01

    The Australian snakes of the genus Pseudonaja (dugite, gwardar and common brown) account for the majority of snake bite related deaths in Australia. Without antivenom treatment, the risk of mortality is significant. There is an accumulating body of evidence to suggest that the efficacy of the antivenom is limited. The current study investigates the protein constituents recognized by the antivenom using 2-DE, immuno-blot techniques and rat tracheal organ bath assays. The 2-DE profiles for all three snake venoms were similar, with major species visualized at 78-132 kDa, 32-45 kDa and 6-15 kDa. Proteins characterized by LC-MS/MS revealed a coagulant toxin (∼42 kDa) and coagulant peptide (∼6 kDa), as well as two PLA 2 (∼14 kDa). Peptides isolated from ∼78 kDa and 15-32 kDa protein components showed no similarity to known protein sequences. Protein recognition by the antivenom occurred predominantly for the higher molecular weight components with little recognition of 6-32 kDa MW species. The ability of antivenom to neutralize venom activity was also investigated using rat tracheal organ bath assays. The venoms of Pseudonaja affinis affinis and Pseudonaja nuchalis incited a sustained, significant contraction of the trachea. These contractions were attributed to PLA 2 enzymatic activity as pre-treatment with the PLA 2 inhibitor 4-BPB attenuated the venom-induced contractions. The venom of Pseudonaja textilis incited tracheal contractility through a non-PLA 2 enzymatic activity. Neither activity was attenuated by the antivenom treatment. These results represent the first proteomic investigation of the venoms from the snakes of the genus Pseudonaja, revealing a possible limitation of the brown snake antivenom in binding to the low MW protein components

  9. Manipulation of single neutral atoms in optical lattices

    International Nuclear Information System (INIS)

    Zhang Chuanwei; Das Sarma, S.; Rolston, S. L.

    2006-01-01

    We analyze a scheme to manipulate quantum states of neutral atoms at individual sites of optical lattices using focused laser beams. Spatial distributions of focused laser intensities induce position-dependent energy shifts of hyperfine states, which, combined with microwave radiation, allow selective manipulation of quantum states of individual target atoms. We show that various errors in the manipulation process are suppressed below 10 -4 with properly chosen microwave pulse sequences and laser parameters. A similar idea is also applied to measure quantum states of single atoms in optical lattices

  10. Neutralization mechanisms in He+-Al surface collisions

    International Nuclear Information System (INIS)

    Bajales, N.; Ferron, J.; Goldberg, E.C.

    2007-01-01

    From a quantum mechanical calculation where the populations of He ground and first excited states are properly taken into account, we can identify for the first time the neutralization to the He first excited state as an operative mechanism in He + -Al surface collisions. This identification allows us to understand the presence of high energy electrons in the ion induced electron emission spectra, through the inclusion of Auger deexcitation as an electron emission source, as well as to suggest a possible cause for the disagreement still found between theory and experiments in low energy ion scattering (LEIS) for this system

  11. Direct Photon and Neutral Mesons Measurements with the ALICE Detector

    CERN Document Server

    Matyja, Adam

    2016-01-01

    The ALICE experiment at LHC is dedicated to studies of the Quark– Gluon Plasma (QGP) state, which is going to be created in heavy-ion collisions. Both photons and neutral mesons are excellent probes for QGP formation. Photons are produced during the different stages of the expan- sion of the initial hot matter fireball. They do not interact strongly with the medium and passing through it, they carry information on their emis- sion point. The prompt photons which are formed at the early stage of the collision enable us to test perturbative QCD constraining parton distri- butions and fragmentation functions. Looking into the regime of thermal photons, one can extract the temperature of the medium. The medium- induced energy loss of particles can be investigated via the measurement of neutral meson spectra for different centrality classes as well as via neutral meson–hadron correlations. A decrease of the nuclear modification factor ( R AA ) with centrality of the collision is observed. The suppression of th...

  12. Unconditional conservatism in Brazilian public companies and tax neutrality

    Directory of Open Access Journals (Sweden)

    Juliana Pinhata Sanches do Vale

    2017-03-01

    Full Text Available ABSTRACT Law n. 11,638/2007 legitimized the International Financial Reporting Standards (IFRS adoption process in Brazil and introduced an accounting system detached from tax purposes in the country. This law aims to reduce the influence of tax law on accounting standards and improve the quality of financial reporting, as IFRS are considered to be higher quality standards. International literature shows a reduction in earnings quality in environments where accounting and tax rules are strongly linked. Moreover, the influence of tax legislation on financial accounting is seen to encourage unconditional conservatism, a bias with no advantages for financial market efficiency. Thus, tax neutrality is expected to provide a more favorable institutional environment for quality financial reporting by detaching corporate accounting from tax accounting. In light of the above, this study aims to verify whether the advent of tax neutrality influences unconditional conservatism in Brazilian public companies. The methodology used involves panel data regressions. The sample consists of non-financial publicly-traded companies with information published in Economática® covering 2002 to 2014. The results show differences in the relationship between taxation and financial reporting between firms that are subject to different levels of monitoring in the Brazilian stock market. Evidence of unconditional conservatism is only found in companies that are subject to greater market monitoring. In this group, it is observed that taxation does not induce unconditional conservatism in reported earnings, which is expected in a tax neutrality context.

  13. Toroidal magnetic confinement of non-neutral plasmas

    International Nuclear Information System (INIS)

    Yoshida, Zensho; Ogawa, Yuichi; Morikawa, Junji; Himura, Haruhiko; Kondo, Shigeo; Nakashima, Chihiro; Kakuno, Shuichi; Iqbal, Muhamad; Volponi, Francesco; Shibayama, Norihisa; Tahara, Shigeru

    1999-01-01

    A new method of toroidal non-neutral plasma trap has been developed with applying the chaos-induced radial transport of particles near a magnetic null point. A pure electron plasma is produced by injecting an electron beam. The poloidal gyroradius of an electron at the energy of 1 keV is of order 10 mm, which determines the length scale of the chaotic region. Amongst various applications of toroidal non-neutral plasmas, a possibility of producing very high-β plasma, which is suitable for advanced fusion, has been examined. The self-electric field of a non-neutral plasma can generate a strong shear flow. When the flow velocity is comparable to the Alfven speed (which is smaller than the ion sound speed, if β>1), a high-β equilibrium can be produced in which the plasma pressure is primarily balanced by the dynamic pressure of the flow. This configuration is described by a generalized Bernoulli law

  14. Model-independent determination of hadronic neutral-current couplings

    International Nuclear Information System (INIS)

    Claudson, M.; Paschos, E.A.; Strait, J.; Sulak, L.R.

    1979-01-01

    Completion of a second generation of experiments on neutrino-induced neutral-current reactions allows a more discriminating study of neutral-current couplings to hadrons. To minimize the sensitivity to model-dependent analyses of inclusive and exclusive pion data, we base our work on measurements of deep-inelastic and elastic reactions alone. Within the regions allowed by the deep-inelastic data for scattering on isoscalar targets, the coupling constants are fit to the q 2 dependence of the neutrino-proton elastic scattering data. This procedure initially yields two solutions for the couplings. One of these, at theta/sub L/ = 55 0 and theta/sub R/ = 205 0 , is predominantly isoscalar and therefore is ruled out by only qualitative consideration of exclusive pion data. The other solution at theta/sub D/ = 140 0 and and theta/sub R/ = 330 0 , is thus a unique determination of the hadronic neutral-current couplings. It coincides with solution A obtained in earlier work, and is insensitive to variations of M/sub A/ within 2 standard deviations of the world average. When constrained to the coupling constants required by the Weinberg-Salam model, the fit agrees with the data to within 1 standard deviation

  15. Interaction of intense laser pulses with neutral gases and preformed plasmas

    International Nuclear Information System (INIS)

    Mackinnon, A. J.; Borghesi, M.; Iwase, A.; Jones, M. W.; Willi, O.

    1998-01-01

    The interaction of a high intensity laser pulse with a neutral gas or preformed plasma has been studied over a wide range of target and laser conditions. It was found that the propagation of 2ps laser pulses (λ=1.054μm, P=5-10TW, I∼5x10 14 -1x10 14 -1x10 18 Wcm -2 ) in neutral gases with atomic densities greater than 0.001 of critical was strongly influenced by ionisation induced refraction. Preformed density channels were effective in overcoming refraction but the channel length was found to be limited by ionization induced defocusing of the prepulse

  16. Snake venom neutralization by Indian medicinal plants (Vitex negundo and Emblica officinalis) root extracts.

    Science.gov (United States)

    Alam, M I; Gomes, A

    2003-05-01

    The methanolic root extracts of Vitex negundo Linn. and Emblica officinalis Gaertn. were explored for the first time for antisnake venom activity. The plant (V. negundo and E. officinalis) extracts significantly antagonized the Vipera russellii and Naja kaouthia venom induced lethal activity both in in vitro and in vivo studies. V. russellii venom-induced haemorrhage, coagulant, defibrinogenating and inflammatory activity was significantly neutralized by both plant extracts. No precipitating bands were observed between the plant extract and snake venom. The above observations confirmed that the plant extracts possess potent snake venom neutralizing capacity and need further investigation.

  17. μ+e-↔μ-e+ transitions via neutral scalar bosons

    International Nuclear Information System (INIS)

    Hou, W.; Wong, G.

    1996-01-01

    With μ→eγ decay forbidden by multiplicative lepton number conservation, we study muonium-antimuonium transitions induced by neutral scalar bosons. Pseudoscalars do not induce conversion for triplet muonium, while, for singlet muonium, pseudoscalar and scalar contributions add constructively. This is in contrast with the usual case of doubly charged scalar exchange, where the conversion rate is the same for both singlet and triplet muonium. Complementary to muonium conversion studies, high energy μ + e - →μ - e + and e - e - →μ - μ - collisions could reveal spectacular resonance peaks for the cases of neutral and doubly charged scalars, respectively. copyright 1996 The American Physical Society

  18. Neutral Color Semitransparent Microstructured Perovskite Solar Cells

    KAUST Repository

    Eperon, Giles E.; Burlakov, Victor M.; Goriely, Alain; Snaith, Henry J.

    2014-01-01

    Neutral-colored semitransparent solar cells are commercially desired to integrate solar cells into the windows and cladding of buildings and automotive applications. Here, we report the use of morphological control of perovskite thin films to form

  19. Charge neutralization of small ion beam clumps

    Energy Technology Data Exchange (ETDEWEB)

    Welch, D R [Mission Research Corp., Albuquerque, NM (United States); Olson, C L; Hanson, D L [Sandia National Labs., Albuquerque, NM (United States)

    1997-12-31

    The mega-ampere currents associated with light ion fusion (LIF) require excellent charge neutralization to prevent divergence growth. As the size and space-charge potential of a beam clump or `beamlet` become small (submillimeter size and kilovolt potentials), the neutralization becomes increasingly difficult. Linear theory predicts that plasma electrons cannot neutralize potentials < {phi}{sub crit} = (1/2)m{sub e}v{sub i}{sup 2}/e, where m{sub e} is the electron mass and v{sub i} is the ion beam velocity. A non-uniform beam would, therefore, have regions with potentials sufficient to add divergence to beam clumps. The neutralization of small beamlets produced on the SABLE accelerator and in numerical simulation has supported the theory, showing a plateau in divergence growths as the potential in the beamlet exceeds {phi}{sub crit}. (author). 1 tab., 2 figs., 4 refs.

  20. 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...

  1. Kinetics of neutralization of Po-218

    International Nuclear Information System (INIS)

    Chu, K.D.

    1987-01-01

    In a well-defined experimental system the neutralization of polonium-218 ions was investigated as a function of the physical and chemical properties of the controlled composition atmosphere. The mobilities of Po + and PoO 2 + are determined by combining experimental results with a computer model of the system. Three neutralization mechanisms were individually studied. The small ion recombination rate has been found to be proportional to the square root of radon concentration. The electron scavenging mechanism is responsible for the neutralization of Po + in NO 2 or H 2 O in nitrogen. When PoO 2 + is formed, the electron transfer mechanism dominates the neutralization process. The electron is transferred to PoO 2 + from molecules with lower ionization potentials. The ionization potential of PoO 2 + is also determined to be 10.44 +/- 0.05 eV

  2. An experimenter's history of neutral currents

    International Nuclear Information System (INIS)

    Sciulli, F.

    1979-01-01

    The history of the experimental study of neutral currents, defined as the class of weak interactions engaged in by lepton pairs of net zero charge, is traced under the headings; historical motivations, experimental searches, first positive indications, neutral currents corroborated, neutrino experiments on neutral currents and some general experimental comments. It is concluded that the neutral current does exist and predicted on the basis of gauge theory ideas, and though to connect the weak and electromagnetic interactions, its very general experimental properties are quite consistent with those ideas. Among these are flavor conserving complicated isospin structure, complicated V, A structure and a structure which depends on the type (or quantum numbers) of the target. 50 references. (UK)

  3. ITER neutral beam system US conceptual design

    International Nuclear Information System (INIS)

    Purgalis, P.

    1990-09-01

    In this document we present the US conceptual design of a neutral beam system for International Thermonuclear Experimental Reactor (ITER). The design incorporates a barium surface conversion D - source feeding a linear array of accelerator channels. The system uses a dc accelerator with electrostatic quadrupoles for strong focusing. A high voltage power supply that is integrated with the accelerator is presented as an attractive option. A gas neutralizer is used and residual ions exiting the neutralizer are deflected to water-cooled dumps. Cryopanels are located at the accelerator exit to pump excess gas from the source and the neutralizer, and in the ion dump cavity to pump re-neutralized ions and neutralizer gas. All the above components are packaged in compact identical, independent modules which can be removed for remote maintenance. The neutral beam system delivers 75 MW of DO at 1.3 MeV, into three ports with a total of 9 modules arranged in stacks of three modules per port . To increase reliability each module is designed to deliver up to 10 MW; this allows eight modules operating at partial capacity to deliver the required power in the event one module is out of service, and provides 20% excess capacity to improve availability. Radiation protection is provided by shielding and by locating critical components in the source and accelerator 46.5 m from the torus centerline. Neutron shielding in the drift duct and neutralizer provides the added feature of limiting conductance and thus reducing gas flow to and from the torus

  4. Neutral-particle-beam production and injection

    International Nuclear Information System (INIS)

    Post, D.; Pyle, R.

    1982-07-01

    This paper is divided into two sections: the first is a discussion of the interactions of neutral beams with confined plasmas, the second is concerned with the production and diagnosis of the neutral beams. In general we are dealing with atoms, molecules, and ions of the isotopes of hydrogen, but some heavier elements (for example, oxygen) will be mentioned. The emphasis will be on single-particle collisions; selected atomic processes on surfaces will be included

  5. Neutral signature Walker-VSI metrics

    International Nuclear Information System (INIS)

    Coley, A; McNutt, D; Musoke, N; Brooks, D; Hervik, S

    2014-01-01

    We will construct explicit examples of four-dimensional neutral signature Walker (but not necessarily degenerate Kundt) spaces for which all of the polynomial scalar curvature invariants vanish. We then investigate the properties of some particular subclasses of Ricci flat spaces. We also briefly describe some four-dimensional neutral signature Einstein spaces for which all of the polynomial scalar curvature invariants are constant. (paper)

  6. 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.

  7. Γ-source Neutral Point Clamped Inverter

    DEFF Research Database (Denmark)

    Mo, Wei; Loh, Poh Chiang; Blaabjerg, Frede

    Transformer based Z-source inverters are recently proposed to achieve promising buck-boost capability. They have improved higher buck-boost capability, smaller size and less components count over Z-source inverters. On the other hand, neutral point clamped inverters have less switching stress...... and better output performance comparing with traditional two-level inverters. Integrating these two types of configurations can help neutral point inverters achieve enhanced votlage buck-boost capability....

  8. TFTR neutral beam injection system conceptual design

    International Nuclear Information System (INIS)

    1975-01-01

    Three subsystems are described in the following chapters: (1) Neutral Beam Injection Line; (2) Power Supplies; and (3) Controls. Each chapter contains two sections: (1) Functions and Design Requirements; this is a brief listing of the requirements of components of the subsystem. (2) Design Description; this section describes the design and cost estimates. The overall performance requirements of the neutral beam injection system are summarized. (MOW)

  9. 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

  10. 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)

  11. 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)

  12. Applications of neutral beam and rf technologies

    International Nuclear Information System (INIS)

    Haselton, H.H.

    1987-04-01

    This presentation provides an update on the applications of neutral beams and radiofrequency (rf) power in the fusion program; highlights of the ion cyclotron heating (ICH) experiments now in progress, as well as the neutral beam experiments; and heating requirements of future devices and some of the available options. Some remarks on current drive are presented because this area of technology is one that is being considered for future devices

  13. Apparatus for neutralization of accelerated ions

    International Nuclear Information System (INIS)

    Fink, J.H.; Frank, A.M.

    1979-01-01

    Apparatus is described for neutralization of a beam of accelerated ions, such as hydrogen negative ions (H - ), using relatively efficient strip diode lasers which emit monochromatically at an appropriate wavelength (lambda = 8000 A for H - ions) to strip the excess electrons by photodetachment. A cavity, formed by two or more reflectors spaced apart, causes the laser beams to undergo multiple reflections within the cavity, thus increasing the efficiency and reducing the illumination required to obtain an acceptable percentage (approx. 85%) of neutralization

  14. 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

  15. Soil microbial community responses to acid exposure and neutralization treatment.

    Science.gov (United States)

    Shin, Doyun; Lee, Yunho; Park, Jeonghyun; Moon, Hee Sun; Hyun, Sung Pil

    2017-12-15

    Changes in microbial community induced by acid shock were studied in the context of potential release of acids to the environment due to chemical accidents. The responses of microbial communities in three different soils to the exposure to sulfuric or hydrofluoric acid and to the subsequent neutralization treatment were investigated as functions of acid concentration and exposure time by using 16S-rRNA gene based pyrosequencing and DGGE (Denaturing Gradient Gel Electrophoresis). Measurements of soil pH and dissolved ion concentrations revealed that the added acids were neutralized to different degrees, depending on the mineral composition and soil texture. Hydrofluoric acid was more effectively neutralized by the soils, compared with sulfuric acid at the same normality. Gram-negative ß-Proteobacteria were shown to be the most acid-sensitive bacterial strains, while spore-forming Gram-positive Bacilli were the most acid-tolerant. The results of this study suggest that the Gram-positive to Gram-negative bacterial ratio may serve as an effective bio-indicator in assessing the impact of the acid shock on the microbial community. Neutralization treatments helped recover the ratio closer to their original values. The findings of this study show that microbial community changes as well as geochemical changes such as pH and dissolved ion concentrations need to be considered in estimating the impact of an acid spill, in selecting an optimal remediation strategy, and in deciding when to end remedial actions at the acid spill impacted site. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Design of the ITER Neutral Beam injectors

    International Nuclear Information System (INIS)

    Hemsworth, R.S.; Feist, J.; Hanada, M.; Heinemann, B.; Inoue, T.; Kuessel, E.; Kulygin, V.; Krylov, A.; Lotte, P.; Miyamoto, K.; Miyamoto, N.; Murdoch, D.; Nagase, A.; Ohara, Y.; Okumura, Y.; Pamela, J.; Panasenkov, A.; Shibata, K.; Tanii, M.

    1996-01-01

    This paper describes the Neutral Beam Injection system which is presently being designed in Europe, Japan and Russia, with co-ordination by the Joint Central Team of ITER at Naka, Japan. The proposed system consists of three negative ion based neutral injectors, delivering a total of 50 MW of 1 MeV D 0 to the ITER plasma for pulse length of ≥1000 s. The injectors each use a single caesiated volume arc discharge negative ion source, and a multi-grid, multi-aperture accelerator, to produce about 40 A of 1 MeV D - . This will be neutralized in a sub-divided gas neutralizer, which has a conversion efficiency of about 60%. The charged fraction of the beam emerging from the neutralizer is dumped in an electrostatic residual ion dump. A water cooled calorimeter can be moved into the beam path to intercept the neutral beam, allowing commissioning of the injector independent of ITER. copyright 1996 American Institute of Physics

  17. Neutral particle kinetics in fusion devices

    International Nuclear Information System (INIS)

    Tendler, M.; Heifetz, D.

    1986-05-01

    The theory of neutral particle kinetics treats the transport of mass, momentum, and energy in a plasma due to neutral particles which themselves are unaffected by magnetic fields. This transport affects the global power and particle balances in fusion devices, as well as profile control and plasma confinement quality, particle and energy fluxes onto device components, performance of pumping systems, and the design of diagnostics and the interpretation of their measurements. This paper reviews the development of analytic, numerical, and Monte Carlo methods of solving the time-independent Boltzmann equation describing neutral kinetics. These models for neutral particle behavior typically use adaptations of techniques developed originally for computing neutron transport, due to the analogy between the two phenomena, where charge-exchange corresponds to scattering and ionization to absorption. Progress in the field depends on developing multidimensional analytic methods, and obtaining experimental data for the physical processes of wall reflection, the neutral/plasma interaction, and for processes in fusion devices which are directly related to neutral transport, such as H/sub α/ emission rates, plenum pressures, and charge-exchange emission spectra

  18. Neutral particle kinetics in fusion devices

    Energy Technology Data Exchange (ETDEWEB)

    Tendler, M.; Heifetz, D.

    1986-05-01

    The theory of neutral particle kinetics treats the transport of mass, momentum, and energy in a plasma due to neutral particles which themselves are unaffected by magnetic fields. This transport affects the global power and particle balances in fusion devices, as well as profile control and plasma confinement quality, particle and energy fluxes onto device components, performance of pumping systems, and the design of diagnostics and the interpretation of their measurements. This paper reviews the development of analytic, numerical, and Monte Carlo methods of solving the time-independent Boltzmann equation describing neutral kinetics. These models for neutral particle behavior typically use adaptations of techniques developed originally for computing neutron transport, due to the analogy between the two phenomena, where charge-exchange corresponds to scattering and ionization to absorption. Progress in the field depends on developing multidimensional analytic methods, and obtaining experimental data for the physical processes of wall reflection, the neutral/plasma interaction, and for processes in fusion devices which are directly related to neutral transport, such as H/sub ..cap alpha../ emission rates, plenum pressures, and charge-exchange emission spectra.

  19. Five-quark model with flavour-changing neutral current and dimuon events

    International Nuclear Information System (INIS)

    Kim, J.E.; Kang, K.

    1976-01-01

    The recent dimuon data seem to suggest either the necessity of flavor-changing hadronic neutral current or proliferation of quarks beyond charm or both. It is shown how a five-quark model based on simple gauge group SU(2) x U(1) x U(1)' can generate the flavor-changing, in particular the needed charm-changing, neutral current in a natural fashion. A substantial D 0 --D -0 mixing can be obtained to account for the ''wrong-sign'' dimuons observed in ν/sub μ/-induced reactions. Because of the role of the extra neutral boson in this model, the flavor-changing neutral current is decoupled from leptonic sectors, thus suppressing the trimuon events as experiments indicate thus far

  20. Study of ν+N→ν+N+π and isospin analysis of the hadronic neutral current

    International Nuclear Information System (INIS)

    Longuemare, C.

    1978-04-01

    Experimental results are presented on neutrino induced single pion production in the bubble chamber Gargamelle filled with a light propane-freon mixture and exposed to the CERN PS neutrino beam. After corrections for reinteractions in the target nuclei, the neutrino neutral current cross section and the branching ratios are determined. The isospin structure of the hadronic neutral current is analysed. The conclusions are compatible with the Weinberg-Salam theory for weak and electromagnetic interactions. The isoscalar component of the neutral current is observed at the level of two standard deviations. The charged to neutral current ratio may be intepreted with the one pion production model of Adler in the framework of the above theory [fr

  1. Automated Facial Coding Software Outperforms People in Recognizing Neutral Faces as Neutral from Standardized Datasets

    Directory of Open Access Journals (Sweden)

    Peter eLewinski

    2015-09-01

    Full Text Available Little is known about people’s accuracy of recognizing neutral faces as neutral. In this paper, I demonstrate the importance of knowing how well people recognize neutral faces. I contrasted human recognition scores of 100 typical, neutral front-up facial images with scores of an arguably objective judge – automated facial coding (AFC software. I hypothesized that the software would outperform humans in recognizing neutral faces because of the inherently objective nature of computer algorithms. Results confirmed this hypothesis. I provided the first-ever evidence that computer software (90% was more accurate in recognizing neutral faces than people were (59%. I posited two theoretical mechanisms, i.e. smile-as-a-baseline and false recognition of emotion, as possible explanations for my findings.

  2. Neutral and emotional episodic memory: global impairment after lorazepam or scopolamine.

    Science.gov (United States)

    Kamboj, Sunjeev K; Curran, H Valerie

    2006-11-01

    Benzodiazepines and anticholinergic drugs have repeatedly been shown to impair episodic memory for emotionally neutral material in humans. However, their effect on memory for emotionally laden stimuli has been relatively neglected. We sought to investigate the effects of the benzodiazepine, lorazepam, and the anticholinergic, scopolamine, on incidental episodic memory for neutral and emotional components of a narrative memory task in humans. A double-blind, placebo-controlled independent group design was used with 48 healthy volunteers to examine the effects of these drugs on emotional and neutral episodic memory. As expected, the emotional memory advantage was retained for recall and recognition memory under placebo conditions. However, lorazepam and scopolamine produced anterograde recognition memory impairments on both the neutral and emotional components of the narrative, although floor effects were obtained for recall memory. Furthermore, compared with placebo, recognition memory for both central (gist) and peripheral (detail) aspects of neutral and emotional elements of the narrative was poorer after either drug. Benzodiazepine-induced GABAergic enhancement or scopolamine-induced cholinergic hypofunction results in a loss of the enhancing effect of emotional arousal on memory. Furthermore, lorazepam- and scopolamine-induced memory impairment for both gist (which is amygdala dependent) and detail raises the possibility that their effects on emotional memory do not depend only on the amygdala. We discuss the results with reference to potential clinical/forensic implications of processing emotional memories under conditions of globally impaired episodic memory.

  3. Hall magnetohydrodynamics of neutral layers

    International Nuclear Information System (INIS)

    Huba, J.D.; Rudakov, L.I.

    2003-01-01

    New analytical and numerical results of the dynamics of inhomogeneous, reversed field current layers in the Hall limit (i.e., characteristic length scales < or approx. the ion inertial length) are presented. Specifically, the two- and three-dimensional evolution of a current layer that supports a reversed field plasma configuration and has a density gradient along the current direction is studied. The two-dimensional study demonstrates that a density inhomogeneity along the current direction can dramatically redistribute the magnetic field and plasma via magnetic shock-like or rarefaction waves. The relative direction between the density gradient and current flow plays a critical role in the evolution of the current sheet. One important result is that the current sheet can become very thin rapidly when the density gradient is directed opposite to the current. The three-dimensional study uses the same plasma and field configuration as the two-dimensional study but is also initialized with a magnetic field perturbation localized along the current channel upstream of the plasma inhomogeneity. The perturbation induces a magnetic wave structure that propagates in the direction of the electron drift (i.e., opposite to the current). The propagating wave structure is a Hall phenomenon associated with magnetic field curvature. The interaction between the propagating wave structure and the evolving current layer can lead to rapid magnetic field line reconnection. The results are applied to laboratory and space plasma processes

  4. Distribution and quantification of Candidatus Liberibacter americanus, agent of huanglongbing disease of citrus in São Paulo State, Brasil, in leaves of an affected sweet orange tree as determined by PCR.

    Science.gov (United States)

    Teixeira, Diva C; Saillard, Colette; Couture, Carole; Martins, Elaine C; Wulff, Nelson A; Eveillard-Jagoueix, Sandrine; Yamamoto, Pedro T; Ayres, Antonio J; Bové, Joseph M

    2008-06-01

    Huanglongbing (HLB), an insect-transmitted disease of citrus, known for many years in Asia and Africa, has appeared in the state of São Paulo State (SSP), Brazil, in 2004, and the state of Florida, USA, in 2005. HLB endangers the very existence of citrus, as trees infected with the bacterial pathogen, irrevocably decline. In the absence of curative procedures, control of HLB is difficult and only based on prevention. Even though not available in culture, the HLB bacterium could be shown to be Gram-negative and to represent a new candidate genus, Candidatus Liberibacter, in the alpha subdivision of the Proteobacteria. Three Candidatus (Ca.) L. species occur: Ca. L. africanus in Africa, Ca. L. asiaticus in Asia, SSP, and Florida, and Ca. L. americanus in SSP. The liberibacters occur exclusively in the phloem sieve tubes. On affected trees, HLB symptoms are often seen on certain branches only, suggesting an uneven distribution of the Liberibacter. Occurrence of Ca. L. americanus, the major HLB agent in SSP, has been examined in 822 leaf samples from an affected sweet orange tree by two conventional PCR techniques and a newly developed real time (RTi) PCR, also used for quantification of the Liberibacter in the leaves. Even though RTi-PCR was able to detect as few as 10 liberibacters per gram of leaf tissue (l/g), no liberibacters could be detected in any of the many leaf samples from a symptomless branch, while in blotchy mottle leaves from symptomatic branches of the same tree, the Liberibacter titer reached values as high as 10(7)l/g. These results demonstrate the uneven distribution of the Liberibacter in HLB-affected trees.

  5. Serbia's Military Neutrality: Origins, effects and challenges

    Directory of Open Access Journals (Sweden)

    Ejdus Filip

    2014-10-01

    Full Text Available Serbia is the only state in the Western Balkans that is not seeking NATO membership. In December 2007, Serbia declared military neutrality and in spite of its EU membership aspirations, developed very close relations with Moscow. The objective of this paper is threefold. First, I argue that in order to understand why Serbia declared military neutrality, one has to look both at the discursive terrain and domestic power struggles. The key narrative that was strategically used by mnemonic entrepreneurs, most importantly by the former Prime Minister Vojislav Koštunica, to legitimize military neutrality was the trauma of NATO intervention in 1999 and the ensuing secession of Kosovo. In the second part of the paper, I discuss the operational consequences of the military neutrality policy for Serbia's relations with NATO and Russia, as well as for military reform and EU accession. Finally, I spell out the challenges ahead in Serbia's neutrality policy and argue that its decision makers will increasingly be caught between pragmatic foreign policy requirements on the one hand and deeply entrenched traumatic memories on the other.

  6. Kinetic Properties of the Neutral Solar Wind

    International Nuclear Information System (INIS)

    Florinski, V.; Heerikhuisen, J.

    2017-01-01

    Charge-exchange collisions between the solar wind protons and interstellar hydrogen produce a distinctive population of neutral hydrogen streaming radially at nearly the solar-wind speed. This tenuous population, known as the neutral solar wind (NSW) is thought to play a key role in the appearance of the Interplanetary Boundary EXplorer ribbon, a bright circular band in the sky that is the source of neutral hydrogen with energies near 1 keV. According to the leading model of the ribbon, the velocity distribution of NSW hydrogen is imparted on the pickup ions (PUIs) generated via charge exchange with the interstellar protons beyond the heliopause, and in this way controls the stability of the resulting ring distribution of PUIs against hydromagnetic wave generation. In this paper, we examine the velocity distributions of the NSW atoms in the heliosphere and the outer heliosheath regions by following the phase-space trajectories of the Boltzmann equation. It is demonstrated that these distributions are highly anisotropic, with the parallel (radial) temperature greatly exceeding the perpendicular temperature. Ions picked up near 90° from the anisotropic NSW would form a stable ring distribution capable of generating the ribbon flux. We also discuss a second population of neutrals born in charge transfer collisions with interstellar PUIs, the so-called neutralized pickup ion (NPI) component. Their high thermal velocities translate into large parallel velocity spread of the daughter ribbon PUIs, which would adversely affect plasma stability in local interstellar space.

  7. Kinetic Properties of the Neutral Solar Wind

    Science.gov (United States)

    Florinski, V.; Heerikhuisen, J.

    2017-03-01

    Charge-exchange collisions between the solar wind protons and interstellar hydrogen produce a distinctive population of neutral hydrogen streaming radially at nearly the solar-wind speed. This tenuous population, known as the neutral solar wind (NSW) is thought to play a key role in the appearance of the Interplanetary Boundary EXplorer ribbon, a bright circular band in the sky that is the source of neutral hydrogen with energies near 1 keV. According to the leading model of the ribbon, the velocity distribution of NSW hydrogen is imparted on the pickup ions (PUIs) generated via charge exchange with the interstellar protons beyond the heliopause, and in this way controls the stability of the resulting ring distribution of PUIs against hydromagnetic wave generation. In this paper, we examine the velocity distributions of the NSW atoms in the heliosphere and the outer heliosheath regions by following the phase-space trajectories of the Boltzmann equation. It is demonstrated that these distributions are highly anisotropic, with the parallel (radial) temperature greatly exceeding the perpendicular temperature. Ions picked up near 90° from the anisotropic NSW would form a stable ring distribution capable of generating the ribbon flux. We also discuss a second population of neutrals born in charge transfer collisions with interstellar PUIs, the so-called neutralized pickup ion (NPI) component. Their high thermal velocities translate into large parallel velocity spread of the daughter ribbon PUIs, which would adversely affect plasma stability in local interstellar space.

  8. Neutral axis as damage sensitive feature

    International Nuclear Information System (INIS)

    Sigurdardottir, D H; Glisic, B

    2013-01-01

    Structural health monitoring (SHM) is the process of continuously or periodically measuring structural parameters and the transformation of the collected data into information on real structural conditions. The centroid of stiffness is a universal parameter and its position in a cross-section can be evaluated for any load-carrying beam structure as the position of the neutral axis under conveniently chosen loads. Thus, a change in the position of the neutral axis within a cross-section can indicate a change in the position of the centroid of stiffness, i.e., unusual structural behaviors. This paper proposes a novel monitoring method based on deterministic and probabilistic determination of the position of the neutral axis under conveniently chosen conditions. Therefore, the method proposed in this paper is potentially applicable to a large variety of beam-like structures. Data from two existing structures were used to validate the method and assess its performance: Streicker Bridge at Princeton University and the US202/NJ23 highway overpass in Wayne, NJ. The results show that the neutral axis location is varying even when damage is not present. Reasons for this variation are determined and the accuracy in the evaluation assessed. This paper concludes that the position of the neutral axis can be evaluated with sufficient accuracy using static and dynamic strain measurements performed on appropriate time-scales and indicates its potential to be used as a damage sensitive feature. (paper)

  9. Neutral axis as damage sensitive feature

    Science.gov (United States)

    Sigurdardottir, D. H.; Glisic, B.

    2013-07-01

    Structural health monitoring (SHM) is the process of continuously or periodically measuring structural parameters and the transformation of the collected data into information on real structural conditions. The centroid of stiffness is a universal parameter and its position in a cross-section can be evaluated for any load-carrying beam structure as the position of the neutral axis under conveniently chosen loads. Thus, a change in the position of the neutral axis within a cross-section can indicate a change in the position of the centroid of stiffness, i.e., unusual structural behaviors. This paper proposes a novel monitoring method based on deterministic and probabilistic determination of the position of the neutral axis under conveniently chosen conditions. Therefore, the method proposed in this paper is potentially applicable to a large variety of beam-like structures. Data from two existing structures were used to validate the method and assess its performance: Streicker Bridge at Princeton University and the US202/NJ23 highway overpass in Wayne, NJ. The results show that the neutral axis location is varying even when damage is not present. Reasons for this variation are determined and the accuracy in the evaluation assessed. This paper concludes that the position of the neutral axis can be evaluated with sufficient accuracy using static and dynamic strain measurements performed on appropriate time-scales and indicates its potential to be used as a damage sensitive feature.

  10. A Measurement of Coherent Neutral Pion Production in Neutrino Neutral Current Interactions in NOMAD experiment

    CERN Document Server

    Kullenberg, C T

    2009-01-01

    We present a study of exclusive neutral pion production in neutrino-nucleus Neutral Current interactions using data from the NOMAD experiment at the CERN SPS. The data correspond to $1.44 \\times 10^6$ muon-neutrino Charged Current interactions in the energy range $2.5 \\leq E_{\

  11. The control of powerful neutral beams

    International Nuclear Information System (INIS)

    Theil, E.; Jacobson, V.

    1986-01-01

    While significant progress has been made in the development of neutral beams for the heating and sustaining of plasmas in large fusion experiments, the control of such devices has largely been a matter of hardware interlocks and operator experience. The need for computer-assisted control becomes more evident, however, with the initiation of multi-beamline experiments. This paper describes a software system that incorporates simple mathematical models coupled to Kalman filters for control of the high power (6 to 8 MW) beams currently under development at Lawrence Berkeley Laboratory's Neutral Beam Engineering Test Facility. Among the principal features of the system are: reduction of a large number of operator variables to just a few (usually one or two); the ability to describe most of the major neutral beams in use and under development; a foundation resting on statistical data analysis and control system principles rather than rules-of-thumb

  12. Neutralization kinetics of charged polymer surface

    Energy Technology Data Exchange (ETDEWEB)

    Mukherjee, S. [Surface Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India); Mukherjee, M. [Surface Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)], E-mail: manabendra.mukherjee@saha.ac.in

    2008-04-15

    In case of photoemission spectroscopy of an insulating material the data obtained from the charged surface are normally distorted due to differential charging. Recently, we have developed a controlled surface neutralization technique to study the kinetics of the surface charging. Using this technique and the associated data analysis scheme with an effective charging model, quantitative information from the apparently distorted photoemission data from PTFE surfaces were extracted. The surface charging was controlled by tuning the electron flood current as well as the X-ray intensity. The effective model was found to describe the charging consistently for both the cases. It was shown that the non-linear neutralization response of differential charging around a critical neutralizing electron flux or a critical X-ray emission current was due to percolation of equipotential surface domains. The obtained value of the critical percolation exponent {gamma} close to unity indicates a percolation similar to that of avalanche breakdown or chain reaction.

  13. 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...... with a critical analysis of their respective operational paradigms, the paper seeks to understand who is framing the debate, how they are doing so, and to what (systemic) effect....... generative: Useful innovations in applications of the internet could take hold easily, and it was difficult – or indeed impossible - for incumbent business interests to disrupt or sabotage them. However, this neutrality is now under threat. New technologies have given incumbent businesses the ability...

  14. Current neutralization of converging ion beams

    International Nuclear Information System (INIS)

    Mosher, D.

    1978-01-01

    It is desired to consider the problem of current neutralization of heavy ion beams traversing gas backgrounds in which the conductivity changes due to beam heating and beam convergence. The procedure is to determine Green's-function solutions to the magnetic-diffusion equation derived from Maxwell's equations and an assumed scaler-plasma conductivity sigma for the background-electron current density j/sub e/. The present calculation is more general than some previously carried out in that arbitrary time variations for the beam current j/sub b/ and conductivity are allowed and the calculation is valid for both weak and strong neutralization. Results presented here must be combined with an appropriate energy-balance equation for the heated background in order to obtain the neutralization self-consistently

  15. Optimal neutral beam heating scenario for FED

    International Nuclear Information System (INIS)

    Hively, L.M.; Houlberg, W.A.; Attenberger, S.E.

    1981-01-01

    Optimal neutral beam heating scenarios are determined for FED based on a 1/one-half/-D transport analysis. Tradeoffs are examined between neutral beam energy, power, and species mix for positive ion systems. A ramped density startup is found to provide the most economical heating. The resulting plasma power requirements are reduced by 10-30% from a constant density startup. For beam energies between 100 and 200 keV, the power needed to heat the plasma does not decrease significantly as beam energy is increased. This is due to reduced ion heating, more power in the fractional energy components, and rising power supply requirements as beam energy increases

  16. Beam divergence scaling in neutral beam injectors

    International Nuclear Information System (INIS)

    Holmes, A.J.T.

    1976-01-01

    One of the main considerations in the design of neutral beam injectors is to monimize the divergence of the primary ion beam and hence maximize the beam transport and minimize the input of thermal gas. Experimental measurements of the divergence of a cylindrical ion beam are presented and these measurements are used to analyze the major components of ion beam divergence, namely: space charge expansion, gas-ion scattering, emittance and optical aberrations. The implication of these divergence components in the design of a neutral beam injector system is discussed and a method of maximizing the beam current is described for a given area of source plasma

  17. Simplified Stability Criteria for Delayed Neutral Systems

    Directory of Open Access Journals (Sweden)

    Xinghua Zhang

    2014-01-01

    Full Text Available For a class of linear time-invariant neutral systems with neutral and discrete constant delays, several existing asymptotic stability criteria in the form of linear matrix inequalities (LMIs are simplified by using matrix analysis techniques. Compared with the original stability criteria, the simplified ones include fewer LMI variables, which can obviously reduce computational complexity. Simultaneously, it is theoretically shown that the simplified stability criteria and original ones are equivalent; that is, they have the same conservativeness. Finally, a numerical example is employed to verify the theoretic results investigated in this paper.

  18. Neutral Naturalness from Orbifold Higgs Models

    Science.gov (United States)

    Craig, Nathaniel; Knapen, Simon; Longhi, Pietro

    2015-02-01

    We present a general class of natural theories in which the Higgs boson is a pseudo-Goldstone boson in an orbifolded gauge theory. The symmetry protecting the Higgs boson at low energies is an accidental global symmetry of the quadratic action, rather than a full continuous symmetry. The lightest degrees of freedom protecting the weak scale carry no standard model (SM) quantum numbers and interact with visible matter principally through the Higgs portal. This opens the door to the systematic study of "neutral naturalness": natural theories with SM-neutral states that are as yet untested by the LHC.

  19. Greenhouse gas neutral Germany in 2050

    International Nuclear Information System (INIS)

    Benndorf, Rosemarie; Bernicke, Maja; Bertram, Andreas

    2014-01-01

    In order to answer the question how a greenhouse gas neutral Germany would look like an interdisciplinary process was started by the Federal Environmental Agency. It was clear from the beginning of this work that a sustainable regenerative energy supply could not be sufficient. Therefore all relevant emission sources were included into the studies: traffic, industry, waste and waste water, agriculture, land usage, land usage changes and forestry. The necessary transformation paths to reach the aim of a greenhouse gas neutral Germany in 2050, economic considerations and political instruments were not part of this study.

  20. PDX neutral-beam reionization losses

    International Nuclear Information System (INIS)

    Kugel, H.W.; Dylla, H.F.; Eubank, H.P.; Kozub, T.A.; Moore, R.; Schilling, G.; Stewart, L.D.; von Halle, A.; Williams, M.D.

    1982-02-01

    Reionization losses for 1.5 MW H 0 and 2 MW D 0 neutral beams injected into the PDX tokamak were studied using pressure gauges, photo-transistors, thermocouples, surface shielding, and surface sample analysis. Considerable outgassing of conventionally prepared 304SS ducts occurred during initial injections and gradually decreased with the cumulative absorption of beam power. Reionization power losses are presently about 5% in the ducts and about 12% total for a beamline including the duct. Present duct pressures are attributed primarily to gas from the ion source and neutralizer with much smaller contributions from residual wall desorption. Physical mechanisms for the observed duct outgassing are discussed

  1. Water absorption in neutralized Nafion membranes

    International Nuclear Information System (INIS)

    Rodmacq, B.; Roche, E.; Pineri, M.; Escoubez, M.; Duplessix, R.; Eisenberg, A.

    1979-01-01

    In this paper some results are reported about the interactions between water and Nafion neutralized with different cations. The energy of water absorption have been measured in the whole range of relative humidity pressures. Moessbauer spectra permit to get information about the change of environment of the iron atoms during the hydration. Small angle neutron and X ray scattering experiments have then been performed to define a possible phase segregation. From these results a model of clustering in the Nafion membranes is proposed. The neutralized Nafion samples have been obtained by soaking the acid samples in solutions containing the different salts

  2. Neutral beam injection in 2XIIB

    International Nuclear Information System (INIS)

    Hibbs, S.M.

    1975-01-01

    Integrated into the operation of the 2XIIB controlled fusion experiment is a 600-A, 20-keV neutral injection system: the highest neutral-beam current capacity of any existing fusion machine. This paper outlines the requirements of the injection system and the design features to which they led. Both mechanical and electrical aspects are discussed. Also included is a brief description of some operational aspects of the system and some of the things we have learned along the way, as well as a short history of the most significant developments

  3. The net neutrality debate on Twitter

    Directory of Open Access Journals (Sweden)

    Wolf J. Schünemann

    2015-12-01

    Full Text Available The internet has been seen as a medium that empowers individual political actors in relation to established political elites and media gatekeepers. The present article discusses this “net empowerment hypothesis” and tests it empirically by analysing Twitter communication on the regulation of net neutrality. We extracted 503.839 tweets containing #NetNeutrality posted between January and March 2015 and analysed central developments and the network structure of the debate. The empirical results show that traditional actors from media and politics still maintain a central role.

  4. Heterotypic Protection and Induction of a Broad Heterotypic Neutralization Response by Rotavirus-Like Particles

    Science.gov (United States)

    Crawford, Sue E.; Estes, Mary K.; Ciarlet, Max; Barone, Christopher; O’Neal, Christine M.; Cohen, Jean; Conner, Margaret E.

    1999-01-01

    The recognition that rotaviruses are the major cause of life-threatening diarrheal disease and significant morbidity in young children has focused efforts on disease prevention and control of these viruses. Although the correlates of protection in children remain unclear, some studies indicate that serotype-specific antibody is important. Based on this premise, current live attenuated reassortant rotavirus vaccines include the four predominant serotypes of virus. We are evaluating subunit rotavirus vaccines, 2/6/7-VLPs and 2/4/6/7-VLPs, that contain only a single VP7 of serotype G1 or G3. In mice immunized parenterally twice, G3 virus-like particles (VLPs) induced a homotypic, whereas G1 VLPs induced a homotypic and heterotypic (G3) serum neutralizing immune response. Administration of three doses of G1 or G3 VLPs induced serum antibodies that neutralized five of seven different serotype test viruses. The inclusion of VP4 in the VLPs was not essential for the induction of heterotypic neutralizing antibody in mice. To confirm these results in another species, rabbits were immunized parenterally with two doses of 2/4/6/7-VLPs containing a G3 or G1 VP7, sequentially with G3 VLPs followed by G1 (G3/G1) VLPs, or with live or psoralen-inactivated SA11. High-titer homotypic serum neutralizing antibody was induced in all rabbits, and low-level heterotypic neutralizing antibody was induced in a subset of rabbits. The rabbits immunized with the G1 or G3/G1 VLPs in QS-21 were challenged orally with live G3 ALA rotavirus. Protection levels were similar in rabbits immunized with homotypic G3 2/4/6/7-VLPs, heterotypic G1 2/4/6/7-VLPs, or G3/G1 2/4/6/7-VLPs. Therefore, G1 2/4/6/7-VLPs can induce protective immunity against a live heterotypic rotavirus challenge in an adjuvant with potential use in humans. Following challenge, broad serum heterotypic neutralizing antibody responses were detected in rabbits parenterally immunized with G1, G3/G1, or G3 VLPs but not with SA11

  5. Molecular evolution of broadly neutralizing Llama antibodies to the CD4-binding site of HIV-1.

    Science.gov (United States)

    McCoy, Laura E; Rutten, Lucy; Frampton, Dan; Anderson, Ian; Granger, Luke; Bashford-Rogers, Rachael; Dekkers, Gillian; Strokappe, Nika M; Seaman, Michael S; Koh, Willie; Grippo, Vanina; Kliche, Alexander; Verrips, Theo; Kellam, Paul; Fassati, Ariberto; Weiss, Robin A

    2014-12-01

    To date, no immunization of humans or animals has elicited broadly neutralizing sera able to prevent HIV-1 transmission; however, elicitation of broad and potent heavy chain only antibodies (HCAb) has previously been reported in llamas. In this study, the anti-HIV immune responses in immunized llamas were studied via deep sequencing analysis using broadly neutralizing monoclonal HCAbs as a guides. Distinct neutralizing antibody lineages were identified in each animal, including two defined by novel antibodies (as variable regions called VHH) identified by robotic screening of over 6000 clones. The combined application of five VHH against viruses from clades A, B, C and CRF_AG resulted in neutralization as potent as any of the VHH individually and a predicted 100% coverage with a median IC50 of 0.17 µg/ml for the panel of 60 viruses tested. Molecular analysis of the VHH repertoires of two sets of immunized animals showed that each neutralizing lineage was only observed following immunization, demonstrating that they were elicited de novo. Our results show that immunization can induce potent and broadly neutralizing antibodies in llamas with features similar to human antibodies and provide a framework to analyze the effectiveness of immunization protocols.

  6. Oblique non-neutral solitary Alfven modes in weakly nonlinear pair plasmas

    International Nuclear Information System (INIS)

    Verheest, Frank; Lakhina, G S

    2005-01-01

    The equal charge-to-mass ratio for both species in pair plasmas induces a decoupling of the linear eigenmodes between waves that are charge neutral or non-neutral, also at oblique propagation with respect to a static magnetic field. While the charge-neutral linear modes have been studied in greater detail, including their weakly and strongly nonlinear counterparts, the non-neutral mode has received less attention. Here the nonlinear evolution of a solitary non-neutral mode at oblique propagation is investigated in an electron-positron plasma. Employing the framework of reductive perturbation analysis, a modified Korteweg-de Vries equation (with cubic nonlinearity) for the lowest-order wave magnetic field is obtained. In the linear approximation, the non-neutral mode has its magnetic component orthogonal to the plane spanned by the directions of wave propagation and of the static magnetic field. The linear polarization is not maintained at higher orders. The results may be relevant to the microstructure in pulsar radiation or to the subpulses

  7. Two-photon LIF on the HIT-SI3 experiment: Absolute density and temperature measurements of deuterium neutrals

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Drew, E-mail: dbelliott@mix.wvu.edu; Siddiqui, Umair; Scime, Earl [Department of Physics and Astronomy, West Virginia University, Morgantown, West Virginia 26056 (United States); Sutherland, Derek; Everson, Chris; Morgan, Kyle; Hossack, Aaron; Nelson, Brian; Jarboe, Tom [Department of Aerospace Engineering, University of Washington, Seattle, Washington 98105 (United States)

    2016-11-15

    Two-photon laser-induced fluorescence measurements were performed on the helicity injected torus (HIT-SI3) device to determine the density and temperature of the background neutral deuterium population. Measurements were taken in 2 ms long pulsed plasmas after the inductive helicity injectors were turned off. Attempts to measure neutrals during the main phase of the plasma were unsuccessful, likely due to the density of neutrals being below the detection threshold of the diagnostic. An unexpectedly low density of atomic deuterium was measured in the afterglow; roughly 100 times lower than the theoretical prediction of 10{sup 17} m{sup −3}. The neutral temperatures measured were on the order of 1 eV. Temporally and spatially resolved neutral density and temperature data are presented.

  8. Daboia russellii and Naja kaouthia venom neutralization by lupeol acetate isolated from the root extract of Indian sarsaparilla Hemidesmus indicus R.Br.

    Science.gov (United States)

    Chatterjee, Ipshita; Chakravarty, A K; Gomes, A

    2006-06-15

    The present study reports the isolation and purification of lupeol acetate from the methanolic root extract of Indian medicinal plant Hemidesmus indicus (L.) R.Br. (family: Asclepiadaceae) which could neutralize venom induced action of Daboia russellii and Naja kaouthia on experimental animals. Lupeol acetate could significantly neutralize lethality, haemorrhage, defibrinogenation, edema, PLA(2) activity induced by Daboia russellii venom. It also neutralized Naja kaouthia venom induced lethality, cardiotoxicity, neurotoxicity and respiratory changes in experimental animals. Lupeol acetate potentiated the protection by snake venom antiserum action against Daboia russellii venom induced lethality in male albino mice. Venom induced changes in lipid peroxidation and super oxide dismutase activity was antagonized by lupeol acetate. Snake venom neutralization by lupeol acetate and its possible mechanism of action has been discussed.

  9. ERP Correlates of Target-Distracter Differentiation in Repeated Runs of a Continuous Recognition Task with Emotional and Neutral Faces

    Science.gov (United States)

    Treese, Anne-Cecile; Johansson, Mikael; Lindgren, Magnus

    2010-01-01

    The emotional salience of faces has previously been shown to induce memory distortions in recognition memory tasks. This event-related potential (ERP) study used repeated runs of a continuous recognition task with emotional and neutral faces to investigate emotion-induced memory distortions. In the second and third runs, participants made more…

  10. First observations of partially neutralized and quasineutral plasmas in the Columbia Non-neutral Torus

    Science.gov (United States)

    Sarasola, Xabier; Brenner, Paul; Hahn, Michael; Pedersen, Thomas

    2009-11-01

    The Columbia Non-neutral Torus (CNT) is the first stellarator devoted to the study of pure electron, partially neutralized and positron-electron plasmas. To date, CNT usually operates with electron rich plasmas (with negligible ion density) [1], but a stellarator can also confine plasmas of arbitrary degree of neutralization. In CNT the accumulation of ions alters the equilibrium of electron plasmas and a global instability has been observed when the ion fraction exceeds 10 %. A characterization of this instability is presented in [2], analyzing its parameter dependence and spatial structure (non- resonant with rational surfaces). A new set of experiments is currently underway studying plasmas of arbitrary degree of neutralization, ranging from pure electron to quasineutral plasmas. Basic observations show that the plasma potential decouples from emitter bias when we increase the degree of the neutralization of our plasmas. Partially neutralized plasmas are also characterized by multiple mode behavior with dominant modes between 20 and 200 kHz. When the plasma becomes quasineutral, it reverts to single mode behavior. The first results on partially neutralized plasmas confined on magnetic surfaces will be presented. [1] J. Kremer, PRL 97, (2006) 095003 [2] Q. Marksteiner, PRL 100 (2008) 065002

  11. How Objective a Neutral Word Is? A Neutrosophic Approach for the Objectivity Degrees of Neutral Words

    Directory of Open Access Journals (Sweden)

    Mihaela Colhon

    2017-11-01

    Full Text Available In the latest studies concerning the sentiment polarity of words, the authors mostly consider the positive and negative constructions, without paying too much attention to the neutral words, which can have, in fact, significant sentiment degrees. More precisely, not all the neutral words have zero positivity or negativity scores, some of them having quite important nonzero scores for these polarities. At this moment, in the literature, a word is considered neutral if its positive and negative scores are equal, which implies two possibilities: (1 zero positive and negative scores; (2 nonzero, but equal positive and negative scores. It is obvious that these cases represent two different categories of neutral words that must be treated separately by a sentiment analysis task. In this paper, we present a comprehensive study about the neutral words applied to English as is developed with the aid of SentiWordNet 3.0: the publicly available lexical resource for opinion mining. We designed our study in order to provide an accurate classification of the so-called “neutral words” described in terms of sentiment scores and using measures from neutrosophy theory. The intended scope is to fill the gap concerning the neutrality aspect by giving precise measurements for the words’ objectivity.

  12. Neutralization escape mutants define a dominant immunogenic neutralization site on hepatitis A virus

    International Nuclear Information System (INIS)

    Stapleton, J.T.; Lemon, S.M.

    1987-01-01

    Hepatitis A virus is an hepatotrophic human picornavirus which demonstrates little antigenic variability. To topologically map immunogenic sites on hepatitis A virus which elicit neutralizing antibodies, eight neutralizing monoclonal antibodies were evaluated in competition immunoassays employing radiolabeled monoclonal antibodies and HM-175 virus. Whereas two antibodies (K3-4C8 and K3-2F2) bound to intimately overlapping epitopes, the epitope bound by a third antibody (B5-B3) was distinctly different as evidenced by a lack of competition between antibodies for binding to the virus. The other five antibodies variably blocked the binding of both K3-4C8-K3-2F2 and B5-B3, suggesting that these epitopes are closely spaced and perhaps part of a single neutralization immunogenic site. Several combinations of monoclonal antibodies blocked the binding of polyclonal human convalescent antibody by greater than 96%, indicating that the neutralization epitopes bound by these antibodies are immunodominant in humans. Spontaneously arising HM-175 mutants were selected for resistance to monoclonal antibody-mediated neutralization. Neutralization resistance was associated with reduced antibody binding. These results suggest that hepatitis A virus may differ from poliovirus in possessing a single, dominant neutralization immunogenic site and therefore may be a better candidate for synthetic peptide or antiidiotype vaccine development

  13. Is a neutral expression also a neutral stimulus? A study with functional magnetic resonance.

    Science.gov (United States)

    Carvajal, Fernando; Rubio, Sandra; Serrano, Juan M; Ríos-Lago, Marcos; Alvarez-Linera, Juan; Pacheco, Lara; Martín, Pilar

    2013-08-01

    Although neutral faces do not initially convey an explicit emotional message, it has been found that individuals tend to assign them an affective content. Moreover, previous research has shown that affective judgments are mediated by the task they have to perform. Using functional magnetic resonance imaging in 21 healthy participants, we focus this study on the cerebral activity patterns triggered by neutral and emotional faces in two different tasks (social or gender judgments). Results obtained, using conjunction analyses, indicated that viewing both emotional and neutral faces evokes activity in several similar brain areas indicating a common neural substrate. Moreover, neutral faces specifically elicit activation of cerebellum, frontal and temporal areas, while emotional faces involve the cuneus, anterior cingulated gyrus, medial orbitofrontal cortex, posterior superior temporal gyrus, precentral/postcentral gyrus and insula. The task selected was also found to influence brain activity, in that the social task recruited frontal areas while the gender task involved the posterior cingulated, inferior parietal lobule and middle temporal gyrus to a greater extent. Specifically, in the social task viewing neutral faces was associated with longer reaction times and increased activity of left dorsolateral frontal cortex compared with viewing facial expressions of emotions. In contrast, in the same task emotional expressions distinctively activated the left amygdale. The results are discussed taking into consideration the fact that, like other facial expressions, neutral expressions are usually assigned some emotional significance. However, neutral faces evoke a greater activation of circuits probably involved in more elaborate cognitive processing.

  14. Neutron production by neutral beam sources

    International Nuclear Information System (INIS)

    Berkner, K.H.; Massoletti, D.J.; McCaslin, J.B.; Pyle, R.V.; Ruby, L.

    1979-11-01

    Neutron yields, from interactions of multiampere 40- to 120-keV deuterium beams with deuterium atoms implanted in copper targets, have been measured in order to provide input data for shielding of neutral-deuterium beam facilities for magnetic fusion experiments

  15. Neutron production by neutral beam sources

    Energy Technology Data Exchange (ETDEWEB)

    Berkner, K.H.; Massoletti, D.J.; McCaslin, J.B.; Pyle, R.V.; Ruby, L.

    1979-11-01

    Neutron yields, from interactions of multiampere 40- to 120-keV deuterium beams with deuterium atoms implanted in copper targets, have been measured in order to provide input data for shielding of neutral-deuterium beam facilities for magnetic fusion experiments.

  16. The buffer effect in neutral electrolyte supercapacitors

    DEFF Research Database (Denmark)

    Thrane Vindt, Steffen; Skou, Eivind M.

    2016-01-01

    The observation that double-layer capacitors based on neutral aqueous electrolytes can have significantly wider usable potential windows than those based on acidic or alkaline electrolytes is studied. This effect is explained by a local pH change taking place at the electrode surfaces, leading...... potassium nitrate as the electrolyte and potassium phosphates as the buffer system....

  17. Special solutions of neutral functional differential equations

    Directory of Open Access Journals (Sweden)

    Győri István

    2001-01-01

    Full Text Available For a system of nonlinear neutral functional differential equations we prove the existence of an -parameter family of "special solutions" which characterize the asymptotic behavior of all solutions at infinity. For retarded functional differential equations the special solutions used in this paper were introduced by Ryabov.

  18. Engineering problems of future neutral beam injectors

    International Nuclear Information System (INIS)

    Fink, J.

    1977-01-01

    Because there is no limit to the energy or power that can be delivered by a neutral-beam injector, its use will be restricted by either its cost, size, or reliability. Studies show that these factors can be improved by the injector design, and several examples, taken from mirror reactor studies, are given

  19. Development of KSTAR Neutral Beam Heating System

    Energy Technology Data Exchange (ETDEWEB)

    Oh, B. H.; Song, W. S.; Yoon, B. J. (and others)

    2007-10-15

    The prototype components of a neutral beam injection (NBI) system have been developed for the KSTAR, and a capability of the manufactured components has been tested. High power ion source, acceleration power supply, other ion source power supplies, neutralizer, bending magnet for ion beam separation, calorimeter, and cryo-sorption pump have been developed by using the domestic technologies and tested for a neutral beam injection of 8 MW per beamline with a pulse duration of 300 seconds. The developed components have been continuously upgraded to achieve the design requirements. The development technology of high power and long pulse neutral beam injection system has been proved with the achievement of 5.2 MW output for a short pulse length and 1.6 MW output for a pulse length of 300 seconds. Using these development technologies, the domestic NB technology has been stabilized under the development of high power ion source, NB beamline components, high voltage and current power supplies, NB diagnostics, NB system operation and control.

  20. ICAN: High power neutral beam generation

    International Nuclear Information System (INIS)

    Moustaizis, S.D.; Lalousis, P.; Perrakis, K.; Auvray, P.; Larour, J.; Ducret, J.E.; Balcou, P.

    2015-01-01

    During the last few years there is an increasing interest on the development of alternative high power new negative ion source for Tokamak applications. The proposed new neutral beam device presents a number of advantages with respect to: the density current, the acceleration voltage, the relative compact dimension of the negative ion source, and the coupling of a high power laser beam for photo-neutralization of the negative ion beam. Here we numerically investigate, using a multi- fluid 1-D code, the acceleration and the extraction of high power ion beam from a Magnetically Insulated Diode (MID). The diode configuration will be coupled to a high power device capable of extracting a current up to a few kA with an accelerating voltage up to MeV. An efficiency of up to 92% of the coupling of the laser beam, is required in order to obtain a high power, up to GW, neutral beam. The new high energy, high average power, high efficiency (up to 30%) ICAN fiber laser is proposed for both the plasma generation and the photo-neutralizer configuration. (authors)

  1. elative controllability of nonlinear neutral Volterra Integrodiferential ...

    African Journals Online (AJOL)

    In this paper we established sufficient conditions for the relative controllability of the nonlinear neutral volterra integro-differential systems with distributed delays in the control. The results were established using the Schauder's fixed point theorem which is an extension of known results. Journal of the Nigerian Association of ...

  2. If It's Neutral, It's Not Technology

    Science.gov (United States)

    Strate, Lance

    2012-01-01

    Taking a media ecology perspective, this article argues that technology cannot be neutral, because it is a form of change, and it has an inherent bias based on the properties of its materials and methods. Additionally, the application of a technology is an intrinsic part of the technology itself, as is technique, instructions, software, or…

  3. Neutral beam data systems at ORNL

    International Nuclear Information System (INIS)

    Stewart, C.R.

    1982-01-01

    A control system for neutral injection beam lines has been designed, implemented, and used with much success. Despite the problems with very high power levels this system is very successful in relieving the operators burdens of slow conditioning, data recording, and mode switching. The use of computer control with multiple beam lines now appears very promising

  4. Risk neutral second best toll pricing.

    Science.gov (United States)

    2011-08-01

    We propose a risk-neutral second best toll pricing scheme to account for the possible no uniqueness : of user equilibrium solutions. The scheme is designed to optimize for the expected objective value : as the UE solution varies within the solution s...

  5. Neutral theory of chemical reaction networks

    International Nuclear Information System (INIS)

    Lee, Sang Hoon; Holme, Petter; Minnhagen, Petter; Bernhardsson, Sebastian; Kim, Beom Jun

    2012-01-01

    To what extent do the characteristic features of a chemical reaction network reflect its purpose and function? In general, one argues that correlations between specific features and specific functions are key to understanding a complex structure. However, specific features may sometimes be neutral and uncorrelated with any system-specific purpose, function or causal chain. Such neutral features are caused by chance and randomness. Here we compare two classes of chemical networks: one that has been subjected to biological evolution (the chemical reaction network of metabolism in living cells) and one that has not (the atmospheric planetary chemical reaction networks). Their degree distributions are shown to share the very same neutral system-independent features. The shape of the broad distributions is to a large extent controlled by a single parameter, the network size. From this perspective, there is little difference between atmospheric and metabolic networks; they are just different sizes of the same random assembling network. In other words, the shape of the degree distribution is a neutral characteristic feature and has no functional or evolutionary implications in itself; it is not a matter of life and death. (paper)

  6. Neutral gas transport modeling with DEGAS 2

    International Nuclear Information System (INIS)

    Karney, C.; Stotler, D.

    1993-01-01

    The authors are currently re-writing the neutral gas transport code, DEGAS, with a view to making it both faster and easier to include new physics. They present model calculations including ionization and charge exchange illustrating the way that reactions are included into DEGAS 2 and its operation on a distributed network of workstations

  7. Niche versus neutrality: a dynamical analysis

    Science.gov (United States)

    Michael Kalyuzhny; Efrat Seri; Rachel Chocron; Curtis H. Flather; Ronen Kadmon; Nadav M. Shnerb

    2014-01-01

    Understanding the forces shaping ecological communities is of crucial importance for basic science and conservation. After 50 years in which ecological theory has focused on either stable communities driven by niche-based forces or nonstable “neutral” communities driven by demographic stochasticity, contemporary theories suggest that ecological communities are driven...

  8. Neutral anion receptors: design and application

    NARCIS (Netherlands)

    Antonisse, M.M.G.; Reinhoudt, David

    1998-01-01

    After the development of synthetic cation receptors in the late 1960s, only in the past decade has work started on the development of synthetic neutral anion receptors. Combination and preorganization of different anion binding groups, like amides, urea moieties, or Lewis acidic metal centers lead

  9. Laser cooling and trapping of neutral atoms

    International Nuclear Information System (INIS)

    Phillips, W.D.

    1998-01-01

    The article is a translation of the lecture given on the occasion of the 1997 Nobel Prize awarding ceremony. The history of the discovery of laser cooling and trapping of neutral atoms is described. An explanation of this phenomenon is presented and the author's personal contribution to the discovery is highlighted. The article is completed by Dr. Phillips' autobiography. (Z.J.)

  10. Possible neutral beam requirements for TFTR upgrades

    International Nuclear Information System (INIS)

    Prichard, B.A. Jr.; Little, R.; Post, D.E.; Schmidt, J.A.

    1977-01-01

    A discussion is provided of possible neutral beam requirements and constraints for a TFTR upgrade. The time scale is the early 80s and beams of 250 keV D 0 , probably using 65 ampere negative ion sources, existing power supplies and vacuum enclosures would be required

  11. Transition radiation of ultrarelativistic neutral particles

    International Nuclear Information System (INIS)

    Grimus, W.; Neufeld, H.

    1994-10-01

    We perform a quantum theoretical calculation of transition radiation by neutral particles with spin 1/2 equipped with magnetic moments and/or electric dipole moments. The limit of vanishing masses is treated exactly for arbitrary refraction index. Finally we apply our result to the solar neutrino flux. (author)

  12. A storage ring for neutral molecules

    NARCIS (Netherlands)

    Crompvoets, F.M.H.

    2005-01-01

    Time-varying inhomogeneous electric fields can be used to manipulate the motion of neutral molecules in phase-space, i.e., position-momentum space, via their electric dipole moment. A theoretical background is given on the motion of the molecules in phase-space. As the forces exerted on the

  13. Modeling of the lithium based neutralizer for ITER neutral beam injector

    Energy Technology Data Exchange (ETDEWEB)

    Dure, F., E-mail: franck.dure@u-psud.fr [LPGP, Laboratoire de Physique des Gaz et Plasmas, CNRS-Universite Paris Sud, Orsay (France); Lifschitz, A.; Bretagne, J.; Maynard, G. [LPGP, Laboratoire de Physique des Gaz et Plasmas, CNRS-Universite Paris Sud, Orsay (France); Simonin, A. [IRFM, Institut de Recherche sur la Fusion Magnetique, CEA Cadarache, 13108 Saint-Paul lez Durance (France); Minea, T. [LPGP, Laboratoire de Physique des Gaz et Plasmas, CNRS-Universite Paris Sud, Orsay (France)

    2012-04-04

    Highlights: Black-Right-Pointing-Pointer We compare different lithium based neutraliser configurations to the deuterium one. Black-Right-Pointing-Pointer We study characteristics of the secondary plasma and the propagation of the 1 MeV beam. Black-Right-Pointing-Pointer Using lithium increases the neutralisation effiency keeping correct beam focusing. Black-Right-Pointing-Pointer Using lithium also reduces the backstreaming effect in direction of the ion source. - Abstract: To achieve thermonuclear temperatures necessary to produce fusion reactions in the ITER Tokamak, additional heating systems are required. One of the main method to heat the plasma ions in ITER will be the injection of energetic neutrals (NBI). In the neutral beam injector, negative ions (D{sup -}) are electrostatically accelerated to 1 MeV, and then stripped of their extra electron via collisions with a target gas, in a structure known as neutralizer. In the current ITER specification, the target gas is deuterium. It has been recently proposed to use lithium vapor instead of deuterium as target gas in the neutralizer. This would allow to reduce the gas load in the NBI vessel and to improve the neutralization efficiency. A Particle-in-Cell Monte Carlo code has been developed to study the transport of the beams and the plasma formation in the neutralizer. A comparison between Li and D{sub 2} based neutralizers made with this code is presented here, as well as a parametric study on the geometry of the Li based neutralizer. Results demonstrate the feasibility of a Li based neutralizer, and its advantages with respect to the deuterium based one.

  14. Misconceptions and false expectations in neutral evolution

    Directory of Open Access Journals (Sweden)

    CARLOS Y. VALENZUELA

    2000-01-01

    Full Text Available Neutral evolution results from random recurrent mutation and genetic drift. A small part of random evolution, that which is related to protein or DNA polymorphisms, is the subject of the Neutral Theory of Evolution. One of the foundations of this theory is the demonstration that the mutation rate (m is equal to the substitution rate. Since both rates are independent of population size, they are independent of drift, which is dependent upon population size. Neutralists have erroneously equated the substitution rate with the fixation rate, despite the fact that they are antithetical conceptions. The neutralists then applied the random walk stochastic model to justify alleles or bases that were fixated or eliminated. In this model, once the allele or base frequencies reach the monomorphic states (values of 1.0 or 0.0, the absorbing barriers, they can no longer return to the polymorphic state. This operates in a pure mathematical model. If recurrent mutation occurs (as in biotic real systems fixation and elimination are impossible. A population of bacteria in which m=10-8 base mutation (or substitution/site/generation and the reproduction rate is 1000 cell cycle/year should replace all its genome bases in approximately 100,000 years. The expected situation for all sites is polymorphism for the four bases rather than monomorphism at 1.0 or 0.0 frequencies. If fixation and elimination of a base for more than 500,000 years are impossible, then most of the neutral theory is untenable. A new complete neutral model, which allows for recurrent substitutions, is proposed here based on recurrent mutation or substitution and drift alone. The model fits a binomial or Poisson distribution and not a geometric one, as does neutral theory.

  15. Electron and ion heat transport with lower hybrid current drive and neutral beam injection heating in ASDEX

    International Nuclear Information System (INIS)

    Soeldner, F.X.; Pereverzev, G.V.; Bartiromo, R.; Fahrbach, H.U.; Leuterer, F.; Murmann, H.D.; Staebler, A.; Steuer, K.H.

    1993-01-01

    Transport code calculations were made for experiments with the combined operation of lower hybrid current drive and heating and of neutral beam injection heating on ASDEX. Peaking or flattening of the electron temperature profile are mainly explained by modifications of the MHD induced electron heat transport. They originate from current profile changes due to lower hybrid and neutral beam current drive and to contributions from the bootstrap current. Ion heat transport cannot be described by one single model for all heating scenarios. The ion heat conductivity is reduced during lower hybrid heated phases with respect to Ohmic and neutral beam heating. (author). 13 refs, 5 figs

  16. Equivalent effect of neutral gas pressure and transverse magnetic field in low-pressure glow discharge plasma

    International Nuclear Information System (INIS)

    Toma, M.; Rusu, Ioana; Pohoata, V.; Mihaila, I.

    2001-01-01

    In the paper it is emphasized the equivalent effect of the neutral gas pressure and the action of a transverse magnetic field (TMF), respectively, on a striated positive plasma column. Experimental and theoretical results prove that the distance between striations has the same variation under the influence of both neutral gas pressure and the action of TMF. The pressure modification as well as the action of a TMF can induce ionization instability in the plasma column which explains the standing striation appearance. (authors)

  17. Tangential neutral-beam--driven instabilities in the Princeton beta experiment

    International Nuclear Information System (INIS)

    Heidbrink, W.W.; Bol, K.; Buchenauer, D.

    1986-01-01

    During tangential neutral-beam injection into the PBX tokamak, bursts of two types of instabilities are observed. One instability occurs in the frequency range 120--210 kHz and the other oscillates predominantly near the frequency of bulk plasma rotation (20--30 kHz). Both instabilities correlate with drops in neutron emission and bursts in charge-exchange neutral flux, indicating that beam ions are removed from the center of the plasma by the instabilities. The central losses are comparable to the losses induced by the fishbone instability during perpendicular injection

  18. Neutral lipid production in Dunaliella salina during osmotic stress and adaptation

    DEFF Research Database (Denmark)

    Yao, Shuo; Lu, Jingquan; Sárossy, Zsuzsa

    2016-01-01

    The salt-tolerant green microalga Dunaliella salina can survive both hyper- and hypo-osmotic shock. Upon osmotic shock, the cells transiently and rapidly decreased or increased in size within minutes and slowly over hours acquired their original cell size and volume. Cell size distribution differs...... significantly in the cultures grown in the salinity range from 1.5 to 15 % NaCl. By using Nile Red fluorescence to detect neutral lipids, it became clear that only hyper-osmotic shock on cells induced transient neutral lipid appearance in D. salina, while those transferred from 9 to 15 % NaCl stimulated...

  19. Plasmons in inhomogeneously doped neutral and charged graphene nanodisks

    Energy Technology Data Exchange (ETDEWEB)

    Silveiro, Iván [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona) (Spain); Javier García de Abajo, F., E-mail: javier.garciadeabajo@icfo.es [ICFO-Institut de Ciencies Fotoniques, Mediterranean Technology Park, 08860 Castelldefels (Barcelona) (Spain); ICREA-Institució Catalana de Recerca i Estudis Avançats, Passeig Lluís Companys, 23, 08010 Barcelona (Spain)

    2014-03-31

    We study plasmons in graphene nanodisks including the effect of inhomogeneity in the distribution of the doping charge. Specifically, we discuss the following two configurations: charged disks containing a fixed amount of additional carriers, which are self-consistently distributed along the surface to produce a uniform DC potential; and neutral disks exposed to a neighboring external point charge. A suitable finite-element method is elaborated to compute the charge density associated with the plasmons in the electrostatic limit. For charged disks, we find dipolar plasmons similar to those of uniformly doped graphene structures, in which the plasmon induced charge piles up near the edges. In contrast, in neutral disks placed near an external point charge, plasmons are strongly localized away from the edges. Surprisingly, a single external electron is enough to trap plasmons. The disks also display axially symmetric dark-plasmons, which can be excited through external illumination by coupling them to a neighboring metallic element. Our results have practical relevance for graphene nanophotonics under inhomogeneous doping conditions.

  20. Experimental Investigation of the Neutral sheet Profile During Magnetic Reconnection

    International Nuclear Information System (INIS)

    Trintchouk, F.; Ji, H.; Yamada, M.; Kulsrud, R.; Hsu, S.; Carter, T.

    1999-01-01

    During magnetic reconnection, a ''neutral sheet'' current is induced, heating the plasma. The resultant plasma thermal pressure forms a stationary equilibrium with the opposing magnetic fields. The reconnection layer profile holds significant clues about the physical mechanisms which control reconnection. On the Magnetic Reconnection Experiment [M. Yamada et al., Phys. Plasmas 4, 1936 (1997)], a quasi steady-state and axisymmetric neutral sheet profile has been measured precisely using a magnetic probe array with spatial resolution equal to one quarter of the ion gyro-radius. It was found that the reconnecting field profile fits well with a Harris-type profile [E. G. Harris, Il Nuovo Cimento 23, 115 (1962)], B(x) approximately tanh(x/delta). This agreement is remarkable since the Harris theory does not take into account reconnection and associated electric fields and dissipation. An explanation for this agreement is presented. The sheet thickness delta is found to be approximately 0.4 times the ion skin depth, which agrees with a generalized Harris theory incorporating non-isothermal electron and ion temperatures and finite electric field. The detailed study of additional local features of the reconnection region is also presented

  1. Solar polar rotation and its effect on heliospheric neutral fluxes

    Science.gov (United States)

    Sokol, J. M.; Grzedzielski, S.; Bzowski, M.

    2016-12-01

    The magnetic field in the solar polar corona exhibit a regular "ray-like" structure associated with large polar coronal holes during solar minimum. The solar rotation twists the magnetic field lines of the expanding fast solar wind over the poles. The twist induces a toroidal component of the polar magnetic field which results in magnetic forces directed towards the rotation axis. That is tantamount to a (weak) zeta pinch, known also in other astrophysical contexts (e.g. AGN plasmas). The pinch compresses the polar solar corona plasma and a cone-like enhancement in the solar wind density forms along the rotation axis. Though the effect is likely very dynamic, a time independent description is used here to get an order-of-magnitude estimate. The weak pinch is treated as a 1st order perturbation to the zero-order radial flow. The obtained density enhancement may affect the near and far heliosphere, modifying the charge-exchange and electron impact ionization rates of neutral atoms in interplanetary space. The charge exchange is the most effective ionization process for hydrogen and oxygen atoms, and electron impact ionization is a significant loss reaction for the helium atoms at close distances to the Sun. The change in the polar density due to the solar polar corona rotation could be of importance in the inner heliosphere for low energy atoms. We will present the influence of this effect on interstellar neutral gas distribution and H ENA fluxes observed by IBEX.

  2. Theory of time-averaged neutral dynamics with environmental stochasticity

    Science.gov (United States)

    Danino, Matan; Shnerb, Nadav M.

    2018-04-01

    Competition is the main driver of population dynamics, which shapes the genetic composition of populations and the assembly of ecological communities. Neutral models assume that all the individuals are equivalent and that the dynamics is governed by demographic (shot) noise, with a steady state species abundance distribution (SAD) that reflects a mutation-extinction equilibrium. Recently, many empirical and theoretical studies emphasized the importance of environmental variations that affect coherently the relative fitness of entire populations. Here we consider two generic time-averaged neutral models; in both the relative fitness of each species fluctuates independently in time but its mean is zero. The first (model A) describes a system with local competition and linear fitness dependence of the birth-death rates, while in the second (model B) the competition is global and the fitness dependence is nonlinear. Due to this nonlinearity, model B admits a noise-induced stabilization mechanism that facilitates the invasion of new mutants. A self-consistent mean-field approach is used to reduce the multispecies problem to two-species dynamics, and the large-N asymptotics of the emerging set of Fokker-Planck equations is presented and solved. Our analytic expressions are shown to fit the SADs obtained from extensive Monte Carlo simulations and from numerical solutions of the corresponding master equations.

  3. Nonequilibrium forces between neutral atoms mediated by a quantum field

    International Nuclear Information System (INIS)

    Behunin, Ryan O.; Hu, Bei-Lok

    2010-01-01

    We study forces between two neutral atoms, modeled as three-dimensional harmonic oscillators, arising from mutual influences mediated by an electromagnetic field but not from their direct interactions. We allow as dynamical variables the center-of-mass motion of the atom, its internal degrees of freedom, and the quantum field treated relativistically. We adopt the method of nonequilibrium quantum field theory which can provide a first-principles, systematic, and unified description including the intrinsic and induced dipole fluctuations. The inclusion of self-consistent back-actions makes possible a fully dynamical description of these forces valid for general atom motion. In thermal equilibrium we recover the known forces--London, van der Waals, and Casimir-Polder--between neutral atoms in the long-time limit. We also reproduce a recently reported force between atoms when the system is out of thermal equilibrium at late times. More noteworthy is the discovery of the existence of a type of (or identification of the source of some known) interatomic force which we call the ''entanglement force,'' originating from the quantum correlations of the internal degrees of freedom of entangled atoms.

  4. Maturation Pathways of Cross-Reactive HIV-1 Neutralizing Antibodies

    Directory of Open Access Journals (Sweden)

    Dimiter S. Dimitrov

    2009-11-01

    Full Text Available Several human monoclonal antibodies (hmAbs and antibody fragments, including the best characterized in terms of structure-function b12 and Fab X5, exhibit relatively potent and broad HIV-1 neutralizing activity. However, the elicitation of b12 or b12-like antibodies in vivo by vaccine immunogens based on the HIV-1 envelope glycoprotein (Env has not been successful. B12 is highly divergent from the closest corresponding germline antibody while X5 is less divergent. We have hypothesized that the relatively high degree of specific somatic hypermutations may preclude binding of the HIV-1 envelope glycoprotein (Env to closest germline antibodies, and that identifying antibodies that are intermediates in the pathways to maturation could help design novel vaccine immunogens to guide the immune system for their enhanced elicitation. In support of this hypothesis we have previously found that a germline-like b12 (monovalent and bivalent scFv as an Fc fusion protein or IgG lacks measurable binding to an Env as measured by ELISA with a sensitivity in the μM range [1]; here we present evidence confirming and expanding these findings for a panel of Envs. In contrast, a germline-like scFv X5 bound Env with high (nM affinity. To begin to explore the maturation pathways of these antibodies we identified several possible b12 intermediate antibodies and tested their neutralizing activity. These intermediate antibodies neutralized only some HIV-1 isolates and with relatively weak potency. In contrast, germline-like scFv X5 neutralized a subset of the tested HIV-1 isolates with comparable efficiencies to that of the mature X5. These results could help explain the relatively high immunogenicity of the coreceptor binding site on gp120 and the abundance of CD4-induced (CD4i antibodies in HIV-1-infected patients (X5 is a CD4i antibody as well as the maturation pathway of X5. They also can help identify antigens that can bind specifically to b12 germline and

  5. Broadly-Reactive Neutralizing and Non-neutralizing Antibodies Directed against the H7 Influenza Virus Hemagglutinin Reveal Divergent Mechanisms of Protection.

    Directory of Open Access Journals (Sweden)

    Gene S Tan

    2016-04-01

    Full Text Available In the early spring of 2013, Chinese health authorities reported several cases of H7N9 influenza virus infections in humans. Since then the virus has established itself at the human-animal interface in Eastern China and continues to cause several hundred infections annually. In order to characterize the antibody response to the H7N9 virus we generated several mouse monoclonal antibodies against the hemagglutinin of the A/Shanghai/1/13 (H7N9 virus. Of particular note are two monoclonal antibodies, 1B2 and 1H5, that show broad reactivity to divergent H7 hemagglutinins. Monoclonal antibody 1B2 binds to viruses of the Eurasian and North American H7 lineages and monoclonal antibody 1H5 reacts broadly to virus isolates of the Eurasian lineage. Interestingly, 1B2 shows broad hemagglutination inhibiting and neutralizing activity, while 1H5 fails to inhibit hemagglutination and demonstrates no neutralizing activity in vitro. However, both monoclonal antibodies were highly protective in an in vivo passive transfer challenge model in mice, even at low doses. Experiments using mutant antibodies that lack the ability for Fc/Fc-receptor and Fc/complement interactions suggest that the protection provided by mAb 1H5 is, at least in part, mediated by the Fc-fragment of the mAb. These findings highlight that a protective response to a pathogen may not only be due to neutralizing antibodies, but can also be the result of highly efficacious non-neutralizing antibodies not readily detected by classical in vitro neutralization or hemagglutination inhibition assays. This is of interest because H7 influenza virus vaccines induce only low hemagglutination inhibiting antibody titers while eliciting robust antibody titers as measured by ELISA. Our data suggest that these binding but non-neutralizing antibodies contribute to protection in vivo.

  6. Confinement studies during neutral beam injection in PLT

    International Nuclear Information System (INIS)

    Goldston, R.; Davis, S.; Eubank, H.

    1980-12-01

    Neutral beam injection experiments on PLT have provided definitive information on ion energy confinement in highly collisionless plasmas. We find that ion thermal conduction is consistent, within a factor of approx. 3, with neoclassical theory, and that anomalous thermal convection of ion energy is a factor of 2-3 less than would be calculated from the INTOR D/sub e/ with a convection loss term of the form 5/2nkTv/sub r/. From our experiments with a shunted TF coil we have found that a single shallow ripple well of 2.5% has a neglible effect on ion energy confinement, even at the lowest collisionality obtainable on PLT. Scrutiny of the analytic theories of ripple induced transport motivated by these experiments, suggests that more theoretical (and perhaps numerical) work is needed in this area

  7. arXiv Dipole portal to heavy neutral leptons

    CERN Document Server

    Magill, Gabriel; Pospelov, Maxim; Tsai, Yu-Dai

    We consider generic neutrino dipole portals between left-handed neutrinos, photons, and right-handed heavy neutral leptons (HNL) with Dirac masses. The dominance of this portal significantly alters the conventional phenomenology of HNLs. We derive a comprehensive set of constraints on the dipole portal to HNLs by utilizing data from LEP, LHC, MiniBooNE, LSND as well as observations of Supernova 1987A and consistency of the standard Big Bang Nucleosynthesis. We calculate projected sensitivities from the proposed high-intensity SHiP beam dump experiment, and the ongoing experiments at the Short-Baseline Neutrino facility at Fermilab. Dipole mediated Primakoff neutrino upscattering and Dalitz-like meson decays are found to be the main production mechanisms in most of the parametric regime under consideration. Proposed explanations of LSND and MiniBooNE anomalies based on HNLs with dipole-induced decays are found to be severely constrained, or to be tested in the future experiments.

  8. Sheet Fluorescence and Annular Analysis of Ultracold Neutral Plasmas

    International Nuclear Information System (INIS)

    Castro, J.; Gao, H.; Killian, T. C.

    2009-01-01

    Annular analysis of fluorescence imaging measurements on Ultracold Neutral Plasmas (UNPs) is demonstrated. Spatially-resolved fluorescence imaging of the strontium ions produces a spectrum that is Doppler-broadened due to the thermal ion velocity and shifted due to the ion expansion velocity. The fluorescence excitation beam is spatially narrowed into a sheet, allowing for localized analysis of ion temperatures within a volume of the plasma with small density variation. Annular analysis of fluorescence images permits an enhanced signal-to-noise ratio compared to previous fluorescence measurements done in strontium UNPs. Using this technique and analysis, plasma ion temperatures are measured and shown to display characteristics of plasmas with strong coupling such as disorder induced heating and kinetic energy oscillations.

  9. State-dependent fluorescence of neutral atoms in optical potentials

    Science.gov (United States)

    Martinez-Dorantes, M.; Alt, W.; Gallego, J.; Ghosh, S.; Ratschbacher, L.; Meschede, D.

    2018-02-01

    Recently we have demonstrated scalable, nondestructive, and high-fidelity detection of the internal state of 87Rb neutral atoms in optical dipole traps using state-dependent fluorescence imaging [M. Martinez-Dorantes, W. Alt, J. Gallego, S. Ghosh, L. Ratschbacher, Y. Völzke, and D. Meschede, Phys. Rev. Lett. 119, 180503 (2017), 10.1103/PhysRevLett.119.180503]. In this paper we provide experimental procedures and interpretations to overcome the detrimental effects of heating-induced trap losses and state leakage. We present models for the dynamics of optically trapped atoms during state-dependent fluorescence imaging and verify our results by comparing Monte Carlo simulations with experimental data. Our systematic study of dipole force fluctuations heating in optical traps during near-resonant illumination shows that off-resonant light is preferable for state detection in tightly confining optical potentials.

  10. Research on Stress Neutral Layer Offset in the Straightening Process

    Directory of Open Access Journals (Sweden)

    Hailian Gui

    2015-01-01

    Full Text Available The stress neutral layer offset is analyzed by theoretical and numerical calculation methods. In traditional straightening theory, the stress neutral layer was consistent with the geometric central layer. However, there is a phenomenon that the stress neutral layer has some offset with the geometric neutral layer. This offset is a very important factor for improving the precision of the straightening force. The formula of the stress neutral layer offset is obtained by a theoretical method and the change law is given by numerical calculation method. The neutral layer offset theory provides the theoretical basis for establishing the model of straightening force precisely.

  11. (IAM Series No 005) Are “Market Neutral” Hedge Funds Really Market Neutral?

    OpenAIRE

    Andrew Patton

    2004-01-01

    One can consider the concept of market neutrality for hedge funds as having breadth and depth: breadth reflects the number of market risks to which a fund is neutral, while depth reflects the completeness of the neutrality of the fund to market risks. We focus on market neutrality depth, and propose five different neutrality concepts. Mean neutrality nests the standard correlation-based definition of neutrality. Variance neutrality, Value-at-Risk neutrality and tail neutrality all relate to t...

  12. Spin-dependent electron emission from metals in the neutralization of He+ ions

    International Nuclear Information System (INIS)

    Alducin, M.; Roesler, M.; Juaristi, J.I.; Muino, R. Diez; Echenique, P.M.

    2005-01-01

    We calculate the spin-polarization of electrons emitted in the neutralization of He + ions interacting with metals. All stages of the emission process are included: the spin-dependent perturbation induced by the projectile, the excitation of electrons in Auger neutralization processes, the creation of a cascade of secondaries, and the escape of the electrons through the surface potential barrier. The model allows us to explain in quantitative terms the measured spin-polarization of the yield in the interaction of spin-polarized He + ions with paramagnetic surfaces, and to disentangle the role played by each of the involved mechanisms. We show that electron-electron scattering processes at the surface determine the spin-polarization of the total yield. High energy emitted electrons are the ones providing direct information on the He + ion neutralization process and on the electronic properties of the surface

  13. Antibody-Mediated Neutralization of the Exotoxin Mycolactone, the Main Virulence Factor Produced by Mycobacterium ulcerans.

    Directory of Open Access Journals (Sweden)

    Jean-Pierre Dangy

    2016-06-01

    Full Text Available Mycolactone, the macrolide exotoxin produced by Mycobacterium ulcerans, causes extensive tissue destruction by inducing apoptosis of host cells. In this study, we aimed at the production of antibodies that could neutralize the cytotoxic activities of mycolactone.Using the B cell hybridoma technology, we generated a series of monoclonal antibodies with specificity for mycolactone from spleen cells of mice immunized with the protein conjugate of a truncated synthetic mycolactone derivative. L929 fibroblasts were used as a model system to investigate whether these antibodies can inhibit the biological effects of mycolactone. By measuring the metabolic activity of the fibroblasts, we found that anti-mycolactone mAbs can completely neutralize the cytotoxic activity of mycolactone.The toxin neutralizing capacity of anti-mycolactone mAbs supports the concept of evaluating the macrolide toxin as vaccine target.

  14. Toroidal confinement of non-neutral plasma - A new approach to high-beta equilibrium

    International Nuclear Information System (INIS)

    Yoshida, Z.; Ogawa, Y.; Morikawa, J.

    2001-01-01

    Departure from the quasi-neutral condition allows us to apply significant two-fluid effects that impart a new freedom to the design of high-performance fusion plasma. The self-electric field in a non-neutralized plasma induces a strong ExB-drift flow. A fast flow produces a large hydrodynamic pressure that can balance with the thermal pressure of the plasma. Basic concepts to produce a toroidal non-neutral plasma have been examined on the internal-conductor toroidal confinement device Proto-RT. A magnetic separatrix determines the boundary of the confinement region. Electrons describe chaotic orbits in the neighborhood of the magnetic null point on the separatrix. The chaos yields collisionless diffusion of electrons from the particle source (electron gun) towards the confinement region. Collisionless heating also occurs in the magnetic null region, which can be applied to produce a plasma. (author)

  15. Summary of fueling by neutral beams

    International Nuclear Information System (INIS)

    Jassby, D.L.

    1978-01-01

    Injected neutral beams supply energy, particles, and momentum to a plasma, while the thermalizing fast ions also increase the fusion reactivity by beam-target or hot-ion reactions. Magnetic mirror machines take advantage of all of these features, with the exception of the momentum input. Neutral-beam injection into toroidal plasmas has been proposed and has so far been utilized mainly as a source of heat, and secondarily as a source of increased neutron production. Nevertheless, fueling by injected beams can also play an important role in toroidal plasmas, especially in the start-up phase of ignited plasmas, or for the quasi-steady maintenance of low-Q plasmas where the average ion energy may exceed the electron energy by a large factor

  16. A new approach to entangling neutral atoms.

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jongmin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Martin, Michael J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jau, Yuan-Yu [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Deutsch, Ivan H. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Biedermann, Grant W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-11-01

    Our team has developed a new approach to entangling neutral atoms with a Rydberg-dressed interaction. Entangling neutral atoms is an essential key of quantum technologies such as quantum computation, many-body quantum simulation, and high-precision atomic sensors . The demonstrated Rydberg-dressed protocol involves adiabatically imposing a light shift on the ground state by coupling an excited Rydberg state with a tuned laser field. Using this technique, we have demonstrated a strong and tunable dipole - dipole interaction between two individually trapped atoms with energy shifts of order 1 MHz, which has been challenging to achieve in other protocols . During this program, we experimentally demonstrated Bell-state entanglement and the isomorphism to the Jaynes - Cumming model of a Rydberg-dressed two-atom system. Our theoretical calculations of a CPHASE quantum logic gate and arbitrary Dicke state quantum control in this system encourage further work.

  17. Particle reflection and TFTR neutral beam diagnostics

    International Nuclear Information System (INIS)

    Kamperschroer, J.H.; Grisham, L.R.; Kugel, H.W.; O'Connor, T.E.; Newman, R.A.; Stevenson, T.N.; von Halle, A.; Williams, M.D.

    1992-04-01

    Determination of two critical neutral beam parameters, power and divergence, are affected by the reflection of a fraction of the incident energy from the surface of the measuring calorimeter. On the TFTR Neutral Beam Test Stand, greater than 30% of the incident power directed at the target chamber calorimeter was unaccounted for. Most of this loss is believed due to reflection from the surface of the flat calorimeter, which was struck at a near grazing incidence (12 degrees). Beamline calorimeters, of a ''V''-shape design, while retaining the beam power, also suffer from reflection effects. Reflection, in this latter case, artificially peaks the power toward the apex of the ''V'', complicating the fitting technique, and increasing the power density on axis by 10 to 20%; an effect of import to future beamline designers. Agreement is found between measured and expected divergence values, even with 24% of the incident energy reflected

  18. Fast Neutral Pressure Gauges in NSTX

    International Nuclear Information System (INIS)

    Raman, R.; Kugel, H.W.; Gernhardt, R.; Provost, T.; Jarboe, T.R.; Soukhanovskii, V.

    2004-01-01

    Successful operation in NSTX of two prototype fast-response micro ionization gauges during plasma operations has motivated us to install five gauges at different toroidal and poloidal locations to measure the edge neutral pressure and its dependence on the type of discharge (L-mode, H-mode, CHI) and the fueling method and location. The edge neutral pressure is also used as an input to the transport analysis codes TRANSP and DEGAS-2. The modified PDX-type Penning gauges are well suited for pressure measurements in the NSTX divertor where the toroidal field is relatively high. Behind the NSTX outer divertor plates where the field is lower, an unshielded fast ion gauge of a new design has been installed. This gauge was developed after laboratory testing of several different designs in a vacuum chamber with applied magnetic fields

  19. Mass separated neutral particle energy analyser

    International Nuclear Information System (INIS)

    Takeuchi, Hiroshi; Matsuda, Toshiaki; Miura, Yukitoshi; Shiho, Makoto; Maeda, Hikosuke; Hashimoto, Kiyoshi; Hayashi, Kazuo.

    1983-09-01

    A mass separated neutral particle energy analyser which could simultaneously measure hydrogen and deuterium atoms emitted from tokamak plasma was constructed. The analyser was calibrated for the energy and mass separation in the energy range from 0.4 keV to 9 keV. In order to investigate the behavior of deuteron and proton in the JFT-2 tokamak plasma heated with ion cyclotron wave and neutral beam injection, this analyser was installed in JFT-2 tokamak. It was found that the energy spectrum could be determined with sufficient accuracy. The obtained ion temperature and ratio of deuteron and proton density from the energy spectrum were in good agreement with the value deduced from Doppler broadening of TiXIV line and the line intensities of H sub(α) and D sub(α) respectively. (author)

  20. Thermal Conductivity of the Multicomponent Neutral Atmosphere

    Science.gov (United States)

    Pavlov, A. V.

    2017-12-01

    Approximate expressions for the thermal conductivity coefficient of the multicomponent neutral atmosphere consisting of N2, O2, O, He, and H are analyzed and evaluated for the atmospheric conditions by comparing them with that given by the rigorous hydrodynamic theory. The new approximations of the thermal conductivity coefficients of simple gases N2, O2, O, He, and H are derived and used. It is proved that the modified Mason and Saxena approximation of the atmospheric thermal conductivity coefficient is more accurate in reproducing the atmospheric values of the rigorous hydrodynamic thermal conductivity coefficient in comparison with those that are generally accepted in atmospheric studies. This approximation of the thermal conductivity coefficient is recommended to use in calculations of the neutral temperature of the atmosphere.