377 research outputs found
Deception Island Volcanism (South Shetland Islands, Antarctica): Results from Thin-Section Invertigations
Experimental ionization of atomic hydrogen with few-cycle pulses
We present the first experimental data on strong-field ionization of atomic
hydrogen by few-cycle laser pulses. We obtain quantitative agreement at the 10%
level between the data and an {\it ab initio} simulation over a wide range of
laser intensities and electron energies
Identification of larval sea basses (Centropristis spp.) using ribosomal DNA-specific molecular assays
This paper is not subject to U.S. copyright. The definitive version was published in Fishery Bulletin 106 (2008): 183-193.The identification of sea
bass (Centropristis) larvae to species
is difficult because of similar
morphological characters, spawning
times, and overlapping species ranges.
Black sea bass (Centropristis striata)
is an important fishery species and
is currently considered to be overfished
south of Cape Hatteras, North
Carolina. We describe methods for
identifying three species of sea bass
larvae using polymerase chain reaction
(PCR) and restriction fragment
length polymorphism (RFLP) assays
based on species-specific amplification
of rDNA internal transcribed
spacer reg ions. The assays were
tested against DNA of ten other cooccurring
reef fish species to ensure
the assay’s specificity. Centropristis
larvae were collected on three cruises
during cross-shelf transects and were
used to validate the assays. Seventysix
Centropristis larvae were assayed
and 69 (91%) were identified successfully.
DNA was not amplified from
5% of the larvae and identification
was inconclusive for 3% of the larvae.
These assays can be used to identify
sea bass eggs and larvae and will help
to assess spawning locations, spawning
times, and larval dispersal.Collection
of larvae at sea was supported by funding from
the National Science Foundation through OCE 9876565
to C. Jones, S. Thorrold, A. Valle-Levinson, and J.
Hare. Additional funding for this project was
provided by Office of National Marine Sanctuaries
and by Grays Reef National Marine
Sanctuary
The nonpolymorphic MHC Qa-1b mediates CD8+ T cell surveillance of antigen-processing defects
The nonclassical major histocompatibility complex (MHC) Qa-1b accommodates monomorphic leader peptides and functions as a ligand for germ line receptors CD94/NKG2, which are expressed by natural killer cells and CD8+ T cells. We here describe that the conserved peptides are replaced by a novel peptide repertoire of surprising diversity as a result of impairments in the antigen-processing pathway. This novel peptide repertoire represents immunogenic neoantigens for CD8+ T cells, as we found that these Qa-1b–restricted T cells dominantly participated in the response to tumors with processing deficiencies. A surprisingly wide spectrum of target cells, irrespective of transformation status, MHC background, or type of processing deficiency, was recognized by this T cell subset, complying with the conserved nature of Qa-1b. Target cell recognition depended on T cell receptor and Qa-1b interaction, and immunization with identified peptide epitopes demonstrated in vivo priming of CD8+ T cells. Our data reveal that Qa-1b, and most likely its human homologue human leukocyte antigen-E, is important for the defense against processing-deficient cells by displacing the monomorphic leader peptides, which relieves the inhibition through CD94/NKG2A on lymphocytes, and by presenting a novel repertoire of immunogenic peptides, which recruits a subset of cytotoxic CD8+ T cells
Genotoxicity in Atlantic killifish (Fundulus heteroclitus) from a PAH-contaminated Superfund site on the Elizabeth River, Virginia
The Atlantic Wood Industries Superfund site (AWI) on the Elizabeth River in Portsmouth, VA is heavily contaminated with polycyclic aromatic hydrocarbons (PAHs) from a wood treatment facility. Atlantic killifish, or mummichog (Fundulus heteroclitus), at this Superfund site are exposed to very high concentrations of several carcinogens. In this study, we measured PAH concentrations in both fish tissues and sediments. Concurrently, we assessed different aspects of genotoxicity in the killifish exposed in situ. Both sediment and tissue PAH levels were significantly higher in AWI samples, relative to a reference site, but the chemistry profile was different between sediments and tissues. Killifish at AWI exhibited higher levels of DNA damage compared to reference fish, as measured via the flow cytometric method (FCM), and the damage was consistent with sediment PAH concentrations. Covalent binding of benzo[a]pyrene (BaP) metabolites to DNA, as measured via LC-MS/MS adduct detection methods, were also elevated and could be partially responsible for the DNA damage. Using similar LC-MS/MS methods, we found no evidence that oxidative DNA adducts had a role in observed genotoxicity
Aerodynamic Shape Optimization of a Blended-Wing-Body Aircraft
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106465/1/AIAA2013-283.pd
How do general practitioners experience providing care to refugees with mental health problems? A qualitative study from Denmark
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
- …