Adsorption of water and organic solvents on the calcite [101¯4] surface: Implications for marble conservation treatments

When exposed outdoors, marble artefacts are subject to degradation caused by dissolution in rain. To improve acid-resistance of marble, surface treatments involving the in situ formation of a passivating calcium phosphate (CaP) layer have been developed. Adding alcohol to the treatment improves CaP coverage but the reason is still unclear. Here, we use computational and experimental studies to ascertain whether the interaction of the organic additives with the marble surface plays a role in determining the treatment outcome. Density functional theory calculations are employed to determine the binding energy of additives on the calcite [101¯4] surface and identify acetone as a promising new additive due to its weak adsorption. Molecular dynamics calculations show that ethanol and isopropanol displace water from the calcite [101¯4] surface forming an immobile, ordered, and hydrophobic layer, while acetone and water form a mixed, dynamic environment. In experimental trials, a continuous (yet cracked) layer of carbonate hydroxyapatite is formed after 24 h, with all organic additives improving the final coating. This result suggests that the interaction of the additive with the marble surface does not play a major role in determining treatment outcomes and other factors should be investigated for the design of improved treatments

Experimental and computational investigations of a normal-hole-bled supersonic boundary layer

A series of experiments have been conducted on a bleed hole array spanning the width of the Cambridge University Engineering Department supersonic wind tunnel at Mach numbers of 1.8 and 2.5. The wind tunnel was run with varying levels of suction, and the flow structure over the bleed array was subsequently mapped with a laser Doppler velocimetry system at a resolution of 0.25 hole diameters or better. The same wind-tunnel setup was simulated using the OVERFLOW Navier–Stokes equation solver. The information obtained was used primarily in qualitative comparisons of flow patterns. Overall good agreement was found in the definition of the expansion fan and barrier shock pattern produced by flow entering the normal holes, as well as three-dimensional flow patterns. Both studies agreed well in terms of measured mass flow rates, to within 1% of the boundary-layer mass flow. The presence of the barrier shock standing off the downstream edge of the bleed holes corresponded with a jet of upward flow, which may provide a mechanism for the generation of streamwise vortices.The experimental research was part funded by Lockheed Martin Corporation, under CUED RG 62670, and by US AFOSR under CUED RG 63860. Computational studies by the U.S. Air Force Research Laboratory through Grant UTC 13-S2 604-04-C20 through Universal Technology Corporation.This is the author accepted manuscript. The final version is available from AIAA via http://dx.doi.org/10.2514/1.J05395

Erythromycin resistance in Streptococcus pyogenes in Italy.

In a prospective study of acute pharyngitis in Italian children, 69 (38.3%) of 180 isolates of Streptococcus pyogenes were resistant to macrolides. S. pyogenes was eradicated in 12 (63.1%) of 19 patients with erythromycin-resistant S. pyogenes treated with clarithromycin and in 22 (88%) of 25 patients with erythromycin-susceptible strains. The constitutive-resistant phenotype was correlated with failure of macrolide treatment

The European project HIALINE (Health Impacts of Airborne Allergen Information Network): results of pollen and allergen of Betula monitoring in Parma (2009)

Introduction. Exposure to allergens is pivotal in determining sensitization and allergic symptoms in individuals. Pollen grain counts in ambient air have traditionally been assessed to estimate airborne allergen exposure. However, the exact allergen content in ambient air is unknown. HIALINE therefore monitored atmospheric concentrations of Betula, Poaceae and Olea pollen grains and matched their major allergens Bet v1, Phl p5 and Ole e1 across Europe. Monitoring the allergens themselves together with pollen in ambient air might be an improvement in allergen exposure assessment. New knowledge through the use of new experimental approaches in the field of aerobiological monitoring will enable better in the prevention and clinical management of pollinosis. In order to disseminate the knowledge of the project we present the results of first year of birch pollen grains and the matched major pollen allergen Bet v1 monitored in Parma (UNIPR), Italy with a short reference to the results obtained by the other participants and about developing models of dissemination and forecasts of pollen and allergens. Materials and methods. The pollen was sampled by a Hirst pollen trap. Allergens was collected with a CHEMVOL® high-volume cascade impactor, extracted from pollen and quantified by ELISA. Antibodies for analysis of Bet v1 are delivered by the industrial partner in this project. Quality control has been carried out for the monitoring pollen activities and allergen concentrations. Results. The project has highlighted that it is possible also to measure pollen allergen in ambient air in different European areas. The results obtained from the center of Parma and other European partners have highlighted the different allergenic powers of pollen of Betula, in different geographical areas. Moreover, daily in each area the allergenic power of pollen grains was very variable. Discussion. HIALINE has been a very important project to understand the mechanisms of sensitization, clinical management of pollinosis and to improve immunotherapy towards a tailored immunotherapy. The results of the project will help medical doctors, authorities and patients, to better manage the different aspects related to pollinosis

Observation of the Shadowing of Cosmic Rays by the Moon using a Deep Underground Detector

Using data collected by the MACRO experiment during the years 1989-1996, we show evidence for the shadow of the moon in the underground cosmic ray flux with a significance of 3.6 sigma. This detection of the shadowing effect is the first by an underground detector. A maximum-likelihood analysis is used to determine that the angular resolution of the apparatus is 0.9+/-0.3 degrees. These results demonstrate MACRO's capabilities as a muon telescope by confirming its absolute pointing ability and quantifying its angular resolution.Comment: 14 pages, 8 figures Submitted to Phys. Rev.

Atmospheric neutrino induced muons in the MACRO detector

A measurement of the flux of neutrino-induced muons using the MACRO detector is presented. Different event topologies, corresponding to different neutrino parent energies can be detected. The upward throughgoing muon sample is the larger event sample. The observed upward-throughgoing muons are 26% fewer than expected and the zenith angle distribution does not fit with the expected one. Assuming neutrino oscillations, both measurements suggest maximum mixing and Dm2 of a few times 10-3 eV2. The other samples are due to the internally produced events and to upward-going stopping muons. These data show a regular deficit of observed events in each angular bin, as expected assuming neutrino oscillations with maximum mixing, in agreement with the analysis of the upward-throughgoing muon sample.Comment: 7 pages 6 figures to appear in the proceedings of XVIII International Conference on Neutrino Physics and Astrophysics (Neutrino'98), Takayama, Japan 4-9 June, 199

Nuclearite search with the MACRO detector at Gran Sasso

In this paper we present the results of a search for nuclearites in the penetrating cosmic radiation using the scintillator and track-etch subdetectors of the MACRO apparatus. The analyses cover the beta =v/c range at the detector depth (3700 hg/cm^2) 10^-5 < beta < 1; for beta = 2 x 10^-3 the flux limit is 2.7 x 10^-16 cm^-2 s^-1 sr^-1 for an isotropic flux of nuclearites, and twice this value for a flux of downgoing nuclearites.Comment: 16 pages, 4 Encapsulated Postscript figures, uses article.sty. Submitted to The European Physical Journal

Activating Killer Immunoglobulin Receptors and HLA-C: A successful combination providing HIV-1 control

Several studies demonstrated a relevant role of polymorphisms located within the HLA-B and -C loci and the Killer Immunoglobulin Receptors (KIRs) 3DL1 and 3DS1 in controlling HIV-1 replication. KIRs are regulatory receptors expressed at the surface of NK and CD8+ T-cells that specifically bind HLA-A and -B alleles belonging to the Bw4 supratype and all the -C alleles expressing the C1 or C2 supratype. We here disclose a novel signature associated with the Elite Controller but not with the long-term nonprogressor status concerning 2DS activating KIRs and HLA-C2 alleles insensitive to miRNA148a regulation. Overall, our findings support a crucial role of NK cells in the control of HIV-1 viremia

Measurement of the atmospheric neutrino-induced upgoing muon flux using MACRO

We present a measurement of the flux of neutrino-induced upgoing muons (~100 GeV) using the MACRO detector. The ratio of the number of observed to expected events integrated over all zenith angles is 0.74 +/- 0.036 (stat) +/- 0.046(systematic) +/- 0.13 (theoretical). The observed zenith distribution for -1.0 < cos(theta) < -0.1 does not fit well with the no oscillation expectation, giving a maximum probability for chi^2 of 0.1%. The acceptance of the detector has been extensively studied using downgoing muons, independent analyses and Monte-Carlo simulations. The other systematic uncertainties cannot be the source of the discrepancies between the data and expectations. We have investigated whether the observed number of events and the shape of the zenith distribution can be explained by a neutrino oscillation hypothesis. Fitting either the flux or zenith distribution independently yields mixing parameters of sin^2 (2theta)=1.0 and delta m^2 of a few times 10^-3 eV^2. However, the observed zenith distribution does not fit well with any expectations giving a maximum probability for chi^2 of 5% for the best oscillation hypothesis, and the combined probability for the shape and number of events is 17%. We conclude that these data favor a neutrino oscillation hypothesis, but with unexplained structure in the zenith distribution not easily explained by either the statistics or systematics of the experiment.Comment: 7 pages (two-column) with 4 figure