4,337 research outputs found

    A dose-dependent plasma signature of the safety and immunogenicity of the rVSV-Ebola vaccine in Europe and Africa.

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    The 2014-2015 Ebola epidemic affected several African countries, claiming more than 11,000 lives and leaving thousands with ongoing sequelae. Safe and effective vaccines could prevent or limit future outbreaks. The recombinant vesicular stomatitis virus-vectored Zaire Ebola (rVSV-ZEBOV) vaccine has shown marked immunogenicity and efficacy in humans but is reactogenic at higher doses. To understand its effects, we examined plasma samples from 115 healthy volunteers from Geneva who received low-dose (LD) or high-dose (HD) vaccine or placebo. Fifteen plasma chemokines/cytokines were assessed at baseline and on days 1, 2 to 3, and 7 after injection. Significant increases in monocyte-mediated MCP-1/CCL2, MIP-1β/CCL4, IL-6, TNF-α, IL-1Ra, and IL-10 occurred on day 1. A signature explaining 68% of cytokine/chemokine vaccine-response variability was identified. Its score was higher in HD versus LD vaccinees and was associated positively with vaccine viremia and negatively with cytopenia. It was higher in vaccinees with injection-site pain, fever, myalgia, chills, and headache; higher scores reflected increasing severity. In contrast, HD vaccinees who subsequently developed arthritis had lower day 1 scores than other HD vaccinees. Vaccine dose did not influence the signature despite its influence on specific outcomes. The Geneva-derived signature associated strongly (ρ = 0.97) with that of a cohort of 75 vaccinees from a parallel trial in Lambaréné, Gabon. Its score in Geneva HD vaccinees with subsequent arthritis was significantly lower than that in Lambaréné HD vaccinees, none of whom experienced arthritis. This signature, which reveals monocytes' critical role in rVSV-ZEBOV immunogenicity and safety across doses and continents, should prove useful in assessments of other vaccines

    Anisotropy of the Mobility of Pentacene from Frustration

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    The bandstructure of pentacene is calculated using first-principles density functional theory. A large anisotropy of the hole and electron effective masses within the molecular planes is found. The band dispersion of the HOMO and the LUMO is analyzed with the help of a tight-binding fit. The anisotropy is shown to be intimately related to the herringbone structure.Comment: Accepted for publication in Synthetic Metal

    Precautionary advice about mobile phones: Public understandings and intended responses

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    The official published version can be obtained from the link below - Copyright @ Taylor & FrancisThere is a widespread academic and policy debate about public responses to precaution in public health campaigns. This paper explores these issues in relation to the precautionary stance adopted in the UK around the regulation of mobile telecommunications. The aim of the paper is to examine the nature of attitudes to precaution, and the way in which these, along with other relevant variables, relate to the intention to adopt relevant behaviours. The results from an experimental study (n = 173) indicate that people distinguish between two dimensions of precaution: firstly in relation to its value or necessity per se and secondly as anchored to notions of governance. The two variables differentially relate to other variables including trust and uncertainty, and are predictive of intended behaviour change indirectly, through worry about mobile phone risks. Precautionary advice was generally interpreted as causing concern rather than providing reassurance. The results suggest that precaution may be considered a valuable stance but this does not mean that it is seen as good governance or that it will reduce concern. Whilst the discourse of precaution is aimed at reducing concern, it appears that the uptake of relevant behaviours is largely triggered by worry

    Magnetic Phase Diagram of GdNi2B2C: Two-ion Magnetoelasticity and Anisotropic Exchange Couplings

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    Extensive magnetization and magnetostriction measurements were carried out on a single crystal of GdNi2B2C along the main tetragonal axes. Within the paramagnetic phase, the magnetic and strain susceptibilities revealed a weak anisotropy in the exchange couplings and two-ion tetragonal-preserving alpha-strain modes. Within the ordered phase, magnetization and magnetostriction revealed a relatively strong orthorhombic distortion mode and rich field-temperature phase diagrams. For H//(100) phase diagram, three field-induced transformations were observed, namely, at: Hd(T), related to the domain alignment; Hr(T), associated with reorientation of the moment towards the c-axis; and Hs(T), defining the saturation process wherein the exchange field is completely counterbalanced. On the other hand, For H//(001) phase diagram, only two field-induced transformations were observed, namely at: Hr(T) and Hs(T). For both phase diagrams, Hs(T) follows the relation Hs[1-(T/Tn)^2]^(1/2)kOe with Hs(T-->0)=128.5(5) kOe and Tn(H=0)=19.5 K. In contrast, the thermal evolution of Hr(T) along the c-axis (much simpler than along the a-axis) follows the relation Hr[1-T/Tr]^(1/3) kOe where Hr(T-->0)=33.5(5) kOe and Tr(H=0)=13.5 K. It is emphasized that the magnetoelastic interaction and the anisotropic exchange coupling are important perturbations and therefore should be explicitly considered if a complete analysis of the magnetic properties of the borocarbides is desired

    Strongly correlated s-wave pairing in the n-type infinite-layer cuprate

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    Quasiparticle tunneling spectra of the electron-doped (n-type) infinite-layer cuprate Sr_{0.9}La_{0.1}CuO_2 reveal characteristics that counter a number of common phenomena in the hole-doped (p-type) cuprates. The optimally doped Sr_{0.9}La_{0.1}CuO_2 with T_c = 43 K exhibits a momentum-independent superconducting gap \Delta = 13.0 +- 1.0 meV that substantially exceeds the BCS value, and the spectral characteristics indicate insignificant quasiparticle damping by spin fluctuations and the absence of pseudogap. The response to quantum impurities in the Cu-sites also differs fundamentally from that of the p-type cuprates with d_{x^2-y^2}-wave pairing symmetry.Comment: 4 pages, 3 figures. Published in Physical Review Letter. Corresponding author: Nai-Chang Yeh (e-mail: [email protected]

    Determinants of antibody persistence across doses and continents after single-dose rVSV-ZEBOV vaccination for Ebola virus disease: an observational cohort study.

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    BACKGROUND: The recombinant vesicular stomatitis virus (rVSV) vaccine expressing the Zaire Ebola virus (ZEBOV) glycoprotein is efficacious in the weeks following single-dose injection, but duration of immunity is unknown. We aimed to assess antibody persistence at 1 and 2 years in volunteers who received single-dose rVSV-ZEBOV in three previous trials. METHODS: In this observational cohort study, we prospectively followed-up participants from the African and European phase 1 rVSV-ZEBOV trials, who were vaccinated once in 2014-15 with 300 000 (low dose) or 10-50 million (high dose) plaque-forming units (pfu) of rVSV-ZEBOV vaccine to assess ZEBOV glycoprotein (IgG) antibody persistence. The primary outcome was ZEBOV glycoprotein-specific IgG geometric mean concentrations (GMCs) measured yearly by ELISA compared with 1 month (ie, 28 days) after immunisation. We report GMCs up to 2 years (Geneva, Switzerland, including neutralising antibodies up to 6 months) and 1 year (Lambaréné, Gabon; Kilifi, Kenya) after vaccination and factors associated with higher antibody persistence beyond 6 months, according to multivariable analyses. Trials and the observational study were registered at ClinicalTrials.gov (Geneva: NCT02287480 and NCT02933931; Kilifi: NCT02296983) and the Pan-African Clinical Trials Registry (Lambaréné PACTR201411000919191). FINDINGS: Of 217 vaccinees from the original studies (102 from the Geneva study, 75 from the Lambaréné study, and 40 from the Kilifi study), 197 returned and provided samples at 1 year (95 from the Geneva study, 63 from the Lambaréné, and 39 from the Kilifi study) and 90 at 2 years (all from the Geneva study). In the Geneva group, 44 (100%) of 44 participants who had been given a high dose (ie, 10-50 million pfu) of vaccine and who were seropositive at day 28 remained seropositive at 2 years, whereas 33 (89%) of 37 who had been given the low dose (ie, 300 000 pfu) remained seropositive for 2 years (p=0·042). In participants who had received a high dose, ZEBOV glycoprotein IgG GMCs decreased significantly between their peak (at 1-3 months) and month 6 after vaccination in Geneva (p0·05). Neutralising antibodies seem to be less durable, with seropositivity dropping from 64-71% at 28 days to 27-31% at 6 months in participants from the Geneva study. INTERPRETATION: Antibody responses to single-dose rVSV-ZEBOV vaccination are sustained across dose ranges and settings, a key criterion in countries where booster vaccinations would be impractical. FUNDING: The Wellcome Trust and Innovative Medicines Initiative 2 Joint Undertaking

    R-values in Low Energy e^+e^- Annihilation

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    This presentation briefly summarizes the recent measurements of R-values in low energy e^+e^- annihilation. The new experiments aimed at reducing the uncertainties in R-values and performed with the upgraded Beijing Spectrometer (BESII) at Beijing Electron Positron Collider (BEPC) in Beijing and with CMD-2 and SND at VEEP-2M in Novosibirsk are reviewed and discussed.Comment: 17 pages, 10 figures, invited presentation at the XIX International Symposium on Lepton and Photon Interactions at High Energy, Stanford University, August 199

    Tin telluride: a weakly co-elastic metal

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    We report resonant ultrasound spectroscopy (RUS), dilatometry/magnetostriction, magnetotransport, magnetization, specific heat, and 119^{119}Sn M\"ossbauer spectroscopy measurements on SnTe and Sn0.995_{0.995}Cr0.005_{0.005}Te. Hall measurements at T=77T=77 K indicate that our Bridgman-grown single crystals have a pp-type carrier concentration of 3.4×10193.4 \times 10^{19} cm3^{-3} and that our Cr-doped crystals have an nn-type concentration of 5.8×10225.8 \times 10^{22} cm3^{-3}. Although our SnTe crystals are diamagnetic over the temperature range 2KT1100K2\, \text{K} \leq T \leq 1100\, \text{K}, the Cr-doped crystals are room temperature ferromagnets with a Curie temperature of 294 K. For each sample type, three-terminal capacitive dilatometry measurements detect a subtle 0.5 micron distortion at Tc85T_c \approx 85 K. Whereas our RUS measurements on SnTe show elastic hardening near the structural transition, pointing to co-elastic behavior, similar measurements on Sn0.995_{0.995}Cr0.005_{0.005}Te show a pronounced softening, pointing to ferroelastic behavior. Effective Debye temperature, θD\theta_D, values of SnTe obtained from 119^{119}Sn M\"ossbauer studies show a hardening of phonons in the range 60--115K (θD\theta_D = 162K) as compared with the 100--300K range (θD\theta_D = 150K). In addition, a precursor softening extending over approximately 100 K anticipates this collapse at the critical temperature, and quantitative analysis over three decades of its reduced modulus finds ΔC44/C44=A(TT0)/T0κ\Delta C_{44}/C_{44}=A|(T-T_0)/T_0|^{-\kappa} with κ=0.50±0.02\kappa = 0.50 \pm 0.02 , a value indicating a three-dimensional softening of phonon branches at a temperature T075T_0 \sim 75 K, considerably below TcT_c. We suggest that the differences in these two types of elastic behaviors lie in the absence of elastic domain wall motion in the one case and their nucleation in the other

    Influence of age, social patterns and nasopharyngeal carriage on antibodies to three conserved pneumococcal surface proteins (PhtD, PcpA and PrtA) in healthy young children

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    The acquisition of specific antibodies is paramount to protect children against pneumococcal diseases, and a better understanding of how age, ethnicity and/or Streptococcus pneumoniae (Spn) nasopharyngeal carriage influence the acquisition of antibodies to pneumococcal surface proteins (PSP) is important for the development of novel serodiagnostic and immunisation strategies. IgG antibody titres against three conserved PSP (PhtD, PcpA and PrtA) in the sera of 451 healthy children aged 1 to 24months from Israel [Jewish (50.1%) and Bedouin (49.9%)] were measured by enzyme-linked immunosorbent assay (ELISA), while nasopharyngeal swabs from these children were assessed for the presence of Spn. Globally, anti-PhtD and anti-PrtA geometric mean concentrations (GMC; EU/ml) were high at <2.5months of age [PhtD: 35.3, 95% confidence interval (CI) 30.6-40.6; PrtA: 71.2, 95 % CI 60-84.5], was lower at 5-7months of age (PhtD: 10, 95 % CI 8-12.4; PrtA: 17.9, 95 % CI 14.4-22.1) and only increased after 11months of age. In contrast, an increase in anti-PcpA was observed at 5-7months of age. Anti-PcpA and anti-PrtA, but not anti-PhtD, were significantly higher in Bedouin children (PcpA: 361.6 vs. 226.3, p = 0.02; PrtA: 67.2 vs. 29.5, p < 0.001) in whom Spn nasopharyngeal carriage was identified earlier (60% vs. 38% of carriers <6months of age, p = 0.002). Spn carriage was associated with significantly higher anti-PSP concentrations in carriers than in non-carriers (p < 0.001 for each PSP). Thus, age, ethnicity and, essentially, nasopharyngeal carriage exert distinct cumulative influences on infant responses to PSP. These specific characteristics are worthwhile to include in the evaluation of pneumococcal seroresponses and the development of new PSP-based vaccine
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