88 research outputs found
Accurate Charge-Dependent Nucleon-Nucleon Potential at Fourth Order of Chiral Perturbation Theory
We present the first nucleon-nucleon potential at
next-to-next-to-next-to-leading order (fourth order) of chiral perturbation
theory. Charge-dependence is included up to next-to-leading order of the
isospin-violation scheme. The accuracy for the reproduction of the NN data
below 290 MeV lab. energy is comparable to the one of phenomenological
high-precision potentials. Since NN potentials of order three and less are
known to be deficient in quantitative terms, the present work shows that the
fourth order is necessary and sufficient for a reliable NN potential derived
from chiral effective Lagrangians. The new potential provides a promising
starting point for exact few-body calculations and microscopic nuclear
structure theory (including chiral many-body forces derived on the same
footing).Comment: 4 pages Revtex including one figur
Progress and challenges in coupled hydrodynamic-ecological estuarine modeling
© The Author(s), 2015. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Estuaries and Coasts 39 (2016): 311-332, doi:10.1007/s12237-015-0011-y.Numerical modeling has emerged over the last several decades as a widely accepted tool for investigations in environmental sciences. In estuarine research, hydrodynamic and ecological models have moved along parallel tracks with regard to complexity, refinement, computational power, and incorporation of uncertainty. Coupled hydrodynamic-ecological models have been used to assess ecosystem processes and interactions, simulate future scenarios, and evaluate remedial actions in response to eutrophication, habitat loss, and freshwater diversion. The need to couple hydrodynamic and ecological models to address research and management questions is clear because dynamic feedbacks between biotic and physical processes are critical interactions within ecosystems. In this review, we present historical and modern perspectives on estuarine hydrodynamic and ecological modeling, consider model limitations, and address aspects of model linkage, skill assessment, and complexity. We discuss the balance between spatial and temporal resolution and present examples using different spatiotemporal scales. Finally, we recommend future lines of inquiry, approaches to balance complexity and uncertainty, and model transparency and utility. It is idealistic to think we can pursue a âtheory of everythingâ for estuarine models, but recent advances suggest that models for both scientific investigations and management applications will continue to improve in terms of realism, precision, and accuracy.NKG, ALA, and RPS acknowledge
support from the USGS Coastal and Marine Geology Program.
DKR gratefully acknowledges support from NSF (OCE-1314642) and NIEHS (1P50-ES021923-01). MJB and JMPV gratefully acknowledge
support from NOAA NOS NCCOS (NA05NOS4781201 and
NA11NOS4780043). MJB and SJL gratefully acknowledge support from
the Strategic Environmental Research and Development ProgramâDefense
Coastal/Estuarine Research Program (RC-1413 and RC-2245)
Nucleon-Nucleon Interaction: A Typical/Concise Review
Nearly a recent century of work is divided to Nucleon-Nucleon (NN)
interaction issue. We review some overall perspectives of NN interaction with a
brief discussion about deuteron, general structure and symmetries of NN
Lagrangian as well as equations of motion and solutions. Meanwhile, the main NN
interaction models, as frameworks to build NN potentials, are reviewed
concisely. We try to include and study almost all well-known potentials in a
similar way, discuss more on various commonly used plain forms for two-nucleon
interaction with an emphasis on the phenomenological and meson-exchange
potentials as well as the constituent-quark potentials and new ones based on
chiral effective field theory and working in coordinate-space mostly. The
potentials are constructed in a way that fit NN scattering data, phase shifts,
and are also compared in this way usually. An extra goal of this study is to
start comparing various potentials forms in a unified manner. So, we also
comment on the advantages and disadvantages of the models and potentials partly
with reference to some relevant works and probable future studies.Comment: 85 pages, 5 figures, than the previous v3 edition, minor changes, and
typos fixe
Chiral two-pion exchange and proton-proton partial-wave analysis
The chiral two-pion exchange component of the long-range pp interaction is
studied in an energy-dependent partial-wave analysis. We demonstrate its
presence and importance, and determine the chiral parameters c_i (i=1,3,4). The
values agree well with those obtained from pion-nucleon amplitudes.Comment: 13 pages, no figure
Variational analysis of drifter positions and model outputs for the reconstruction of surface currents in the central Adriatic during fall 2002
Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 113 (2008): C04004, doi:10.1029/2007JC004148.In this paper we present an application of a variational method for the reconstruction of the velocity field in a coastal flow in the central Adriatic Sea, using in situ data from surface drifters and outputs from the ROMS circulation model. The variational approach, previously developed and tested for mesoscale open ocean flows, has been improved and adapted to account for inhomogeneities on boundary current dynamics over complex bathymetry and coastline and for weak Lagrangian persistence in coastal flows. The velocity reconstruction is performed using nine drifter trajectories over 45 d, and a hierarchy of indirect tests is introduced to evaluate the results as the real ocean state is not known. For internal consistency and impact of the analysis, three diagnostics characterizing the particle prediction and transport, in terms of residence times in various zones and export rates from the boundary current toward the interior, show that the reconstruction is quite effective. A qualitative comparison with sea color data from the MODIS satellite images shows that the reconstruction significantly improves the description of the boundary current with respect to the ROMS model first guess, capturing its main features and its exchanges with the interior when sampled by the drifters.Four of the authors are supported by the
Office of Naval Research, V.T. and A.G. under grants N00014-05-1-0094
and N00014-05-1-0095, P.M.P. under grant N00014-03-1-0291, and S.C.
under grant N00014-05-1-0730. CNR-ISMAR
activity was partially supported by P.O.R. ââCAINOââ (Regione Puglia),
VECTOR (Italian MIUR) project, and ECOOP (EU project)
Comparative assessment of multiple COVID-19 serological technologies supports continued evaluation of point-of-care lateral flow assays in hospital and community healthcare settings
There is a clear requirement for an accurate SARS-CoV-2 antibody test, both as a complement to existing diagnostic capabilities and for determining community seroprevalence. We therefore evaluated the performance of a variety of antibody testing technologies and their potential use as diagnostic tools. Highly specific in-house ELISAs were developed for the detection of anti-spike (S), -receptor binding domain (RBD) and -nucleocapsid (N) antibodies and used for the cross-comparison of ten commercial serological assays-a chemiluminescence-based platform, two ELISAs and seven colloidal gold lateral flow immunoassays (LFIAs)-on an identical panel of 110 SARS-CoV-2-positive samples and 50 pre-pandemic negatives. There was a wide variation in the performance of the different platforms, with specificity ranging from 82% to 100%, and overall sensitivity from 60.9% to 87.3%. However, the head-to-head comparison of multiple sero-diagnostic assays on identical sample sets revealed that performance is highly dependent on the time of sampling, with sensitivities of over 95% seen in several tests when assessing samples from more than 20 days post onset of symptoms. Furthermore, these analyses identified clear outlying samples that were negative in all tests, but were later shown to be from individuals with mildest disease presentation. Rigorous comparison of antibody testing platforms will inform the deployment of point-of-care technologies in healthcare settings and their use in the monitoring of SARS-CoV-2 infections
U.S. IOOS coastal and ocean modeling testbed : inter-model evaluation of tides, waves, and hurricane surge in the Gulf of Mexico
© The Author(s), 2013. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Journal of Geophysical Research: Oceans 118 (2013): 5129â5172, doi:10.1002/jgrc.20376.A Gulf of Mexico performance evaluation and comparison of coastal circulation and wave models was executed through harmonic analyses of tidal simulations, hindcasts of Hurricane Ike (2008) and Rita (2005), and a benchmarking study. Three unstructured coastal circulation models (ADCIRC, FVCOM, and SELFE) validated with similar skill on a new common Gulf scale mesh (ULLR) with identical frictional parameterization and forcing for the tidal validation and hurricane hindcasts. Coupled circulation and wave models, SWAN+ADCIRC and WWMII+SELFE, along with FVCOM loosely coupled with SWAN, also validated with similar skill. NOAA's official operational forecast storm surge model (SLOSH) was implemented on local and Gulf scale meshes with the same wind stress and pressure forcing used by the unstructured models for hindcasts of Ike and Rita. SLOSH's local meshes failed to capture regional processes such as Ike's forerunner and the results from the Gulf scale mesh further suggest shortcomings may be due to a combination of poor mesh resolution, missing internal physics such as tides and nonlinear advection, and SLOSH's internal frictional parameterization. In addition, these models were benchmarked to assess and compare execution speed and scalability for a prototypical operational simulation. It was apparent that a higher number of computational cores are needed for the unstructured models to meet similar operational implementation requirements to SLOSH, and that some of them could benefit from improved parallelization and faster execution speed.This project was supported by NOAA
via the U.S. IOOS Office (award: NA10NOS0120063 and
NA11NOS0120141
Seafloor character and sedimentary processes in eastern Long Island Sound and western Block Island Sound
Author Posting. © The Author(s), 2006. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in Geo-Marine Letters 26 (2006): 59-68, doi: 10.1007/s00367-006-0016-4.Multibeam bathymetric data and seismic-reflection profiles collected in eastern Long
Island and western Block Island Sounds reveal previously unrecognized glacial features and
modern bedforms. Glacial features include an ice-sculptured bedrock surface, a newly identified
recessional moraine, exposed glaciolacustrine sediments, and remnants of stagnant-ice-contact
deposits. Modern bedforms include fields of transverse sand waves, barchanoid waves, giant scour
depressions, and pockmarks. Bedform asymmetry and scour around obstructions indicate that net
sediment transport is westward across the northern par of the study area near Fishers Island and
eastward across the southern par near Great Gull Island.This work was supported by the Coastal and Marine Geology Program of the U.S. Geological Survey, the Connecticut Department of Environmental Protection, and the Atlantic Hydrographic Branch of the
National Oceanic and Atmospheric Administration
Real-world evaluation of a novel technology for quantitative simultaneous antibody detection against multiple SARS-CoV-2 antigens in a cohort of patients presenting with COVID-19 syndrome
This is the final version. Available from the publisher via the DOI in this record.An evaluation of a rapid portable gold-nanotechnology measuring SARS-CoV-2 IgM, IgA and IgG antibody concentrations against spike 1 (S1), spike 2 (S) and nucleocapsid (N) was conducted using serum
samples from 74 patients tested for SARS-CoV-2 RNA on admission to hospital, and 47 historical control
patients from March 2019. 59 patients were RNA(+) and 15 were RNA(â). A serum (±) classification was
derived for all three antigens and a quantitative serological profile was obtained. Serum(+) was identified
in 30% (95% CI 11â48) of initially RNA(â) patients, in 36% (95% CI 17â54) of RNA(+) patients before 10
days, 77% (95% CI 67â87) between 10 and 20 days and 95% (95% CI 86â100) after 21 days. The patientlevel diagnostic accuracy relative to RNA(±) after 10 days displayed 88% sensitivity (95% CI 75â95) and
75% specificity (95% CI 22â99), although specificity compared with historical controls was 100% (95%CI
91â100). This study provides robust support for further evaluation and validation of this novel technology
in a clinical setting and highlights challenges inherent in assessment of serological tests for an emerging
disease such as COVID-19.Engineering and Physical Sciences Research Council (EPSRC)Attomarker Lt
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