984 research outputs found
Coastal flood implications of 1.5 {\deg}C, 2.0 {\deg}C, and 2.5 {\deg}C temperature stabilization targets in the 21st and 22nd century
Sea-level rise (SLR) is magnifying the frequency and severity of coastal
flooding. The rate and amount of global mean sea-level (GMSL) rise is a
function of the trajectory of global mean surface temperature (GMST).
Therefore, temperature stabilization targets (e.g., 1.5 {\deg}C and 2.0 {\deg}C
of warming above pre-industrial levels, as from the Paris Agreement) have
important implications for coastal flood risk. Here, we assess differences in
the return periods of coastal floods at a global network of tide gauges between
scenarios that stabilize GMST warming at 1.5 {\deg}C, 2.0 {\deg}C, and 2.5
{\deg}C above pre-industrial levels. We employ probabilistic, localized SLR
projections and long-term hourly tide gauge records to construct estimates of
the return levels of current and future flood heights for the 21st and 22nd
centuries. By 2100, under 1.5 {\deg}C, 2.0 {\deg}C, and 2.5 {\deg}C GMST
stabilization, median GMSL is projected to rise 47 cm with a very likely range
of 28-82 cm (90% probability), 55 cm (very likely 30-94 cm), and 58 cm (very
likely 36-93 cm), respectively. As an independent comparison, a semi-empirical
sea level model calibrated to temperature and GMSL over the past two millennia
estimates median GMSL will rise within < 13% of these projections. By 2150,
relative to the 2.0 {\deg}C scenario, GMST stabilization of 1.5 {\deg}C
inundates roughly 5 million fewer inhabitants that currently occupy lands,
including 40,000 fewer individuals currently residing in Small Island
Developing States. Relative to a 2.0 {\deg}C scenario, the reduction in the
amplification of the frequency of the 100-yr flood arising from a 1.5 {\deg}C
GMST stabilization is greatest in the eastern United States and in Europe, with
flood frequency amplification being reduced by about half
Search for Intrinsic Excitations in 152Sm
The 685 keV excitation energy of the first excited 0+ state in 152Sm makes it
an attractive candidate to explore expected two-phonon excitations at low
energy. Multiple-step Coulomb excitation and inelastic neutron scattering
studies of 152Sm are used to probe the E2 collectivity of excited 0+ states in
this "soft" nucleus and the results are compared with model predictions. No
candidates for two-phonon K=0+ quadrupole vibrational states are found. A 2+,
K=2 state with strong E2 decay to the first excited K=0+ band and a probable 3+
band member are established.Comment: 4 pages, 6 figures, accepted for publication as a Rapid Communication
in Physical Review
Applied Plasma Research
Contains reports on two research projects.National Science Foundation (Grant GK-28282X1)National Science Foundation (Grant GK-33843)U. S. Army - Research Office - Durham (Contract DAHC04-72-C-0044
In vivo testing of novel vaccine prototypes against Actinobacillus pleuropneumoniae
Actinobacillus pleuropneumoniae (A. pleuropneumoniae) is a Gram-negative bacterium that represents the main cause of porcine pleuropneumonia in pigs, causing significant economic losses to the livestock industry worldwide. A. pleuropneumoniae, as the majority of Gram-negative bacteria, excrete vesicles from its outer membrane (OM), accordingly defined as outer membrane vesicles (OMVs). Thanks to their antigenic similarity to the OM, OMVs have emerged as a promising tool in vaccinology. In this study we describe the in vivo testing of several vaccine prototypes for the prevention of infection by all known A. pleuropneumoniae serotypes. Previously identified vaccine candidates, the recombinant proteins ApfA and VacJ, administered individually or in various combinations with the OMVs, were employed as vaccination strategies. Our data show that the addition of the OMVs in the vaccine formulations significantly increased the specific IgG titer against both ApfA and VacJ in the immunized animals, confirming the previously postulated potential of the OMVs as adjuvant. Unfortunately, the antibody response raised did not translate into an effective protection against A. pleuropneumoniae infection, as none of the immunized groups following challenge showed a significantly lower degree of lesions than the controls. Interestingly, quite the opposite was true, as the animals with the highest IgG titers were also the ones bearing the most extensive lesions in their lungs. These results shed new light on A. pleuropneumoniae pathogenicity, suggesting that antibody-mediated cytotoxicity from the host immune response may play a central role in the development of the lesions typically associated with A. pleuropneumoniae infections
Interatomic potentials for atomistic simulations of the Ti-Al system
Semi-empirical interatomic potentials have been developed for Al, alpha-Ti,
and gamma-TiAl within the embedded atomic method (EAM) by fitting to a large
database of experimental as well as ab-initio data. The ab-initio calculations
were performed by the linear augmented plane wave (LAPW) method within the
density functional theory to obtain the equations of state for a number of
crystal structures of the Ti-Al system. Some of the calculated LAPW energies
were used for fitting the potentials while others for examining their quality.
The potentials correctly predict the equilibrium crystal structures of the
phases and accurately reproduce their basic lattice properties. The potentials
are applied to calculate the energies of point defects, surfaces, planar faults
in the equilibrium structures. Unlike earlier EAM potentials for the Ti-Al
system, the proposed potentials provide reasonable description of the lattice
thermal expansion, demonstrating their usefulness in the molecular dynamics or
Monte Carlo studies at high temperatures. The energy along the tetragonal
deformation path (Bain transformation) in gamma-TiAl calculated with the EAM
potential is in a fairly good agreement with LAPW calculations. Equilibrium
point defect concentrations in gamma-TiAl are studied using the EAM potential.
It is found that antisite defects strongly dominate over vacancies at all
compositions around stoichiometry, indicating that gamm-TiAl is an antisite
disorder compound in agreement with experimental data.Comment: 46 pages, 6 figures (Physical Review B, in press
Effects of partially dismantling the CD4 binding site glycan fence of HIV-1 envelope glycoprotein trimers on neutralizing antibody induction
Previously, VLPs bearing JR-FL strain HIV-1 Envelope trimers elicited potent neutralizing antibodies (nAbs) in 2/8 rabbits PLoS Pathog 11(5): e1004932) by taking advantage of a naturally absent glycan at position 197 that borders the CD4 binding site (CD4bs). In new immunizations, we attempted to improve nAb responses by removing the N362 glycan that also lines the CD4bs. All 4 rabbits developed nAbs. One targeted the N197 glycan hole like our previous sera. Two sera depended on the N463 glycan, again suggesting CD4bs overlap. Heterologous boosts appeared to reduce nAb clashes with the N362 glycan. The fourth serum targeted a N362 glycan-sensitive epitope. VLP manufacture challenges prevented us from immunizing larger rabbit numbers to empower a robust statistical analysis. Nevertheless, trends suggest that targeted glycan removal may improve nAb induction by exposing new epitopes and that it may be possible to modify nAb speciUcity using rational heterologous boosts
Applied Plasma Research
Contains research objectives, summary of research and reports on four research projects.National Science Foundation (Grant GK-28282X1)National Science Foundation (Grant GK-33843
Plasma Dynamics
Contains reports on ten research projects split into two sections.National Science Foundation (Grant ENG77-00340)U.S. Department of Energy (Contract EY-76-S-02-2766)U.S. Air Force - Office of Scientific Research (Grant AFOSR-77-3143)U.S. Department of Energy (Contract ET-78-C-01-3019)U.S. Department of Energy (Contract ET-78-S-02-4681)U.S. Department of Energy (Contract ET-78-S-02-4682)U.S. Department of Energy (Grant EG-77-G-01-4107)U.S. Department of Energy (Contract ET-78-S-02-4714)U.S. Department of Energy (Contract ET-78-S-02-4886)U.S. Department of Energy (Contract ET-78-S-02-4690
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