971 research outputs found
Comment on "Tectonic Rotations in Extensional Regimes and Their Paleomagnetic Consequences for Ocean Basalts" by Kenneth L. Verosub and Eldridge M. Moores
One of the more intriguing results from palcomagnetic studies
of Deep Sea Drilling Project (DSDP) basalts is that a
surprisingly large number of samples have inclinations that
deviate significantly from expected values. Vetosub and
Moores [1981] sought to account for what appear to be systematic
departures of mean inclination at several DSDP basement
sites in terms of tectonic rotations along listtic normal
faults. Such rotations, about horizontal axes perpendicular to
the extension direction and typically amounting to 30ø-50 ø
but as large as 70 ø to 90 ø, were suggested to be characteristic
of an extensional tectonic regime such as near an ocean
spreading ridge system. There is a clear implication that large
tectonic rotations are a characteristic process associated with
ocean crust formation
Electrically conductive, optically transparent polymer/carbon nanotube composites and process for preparation thereof
The present invention is directed to the effective dispersion of carbon nanotubes (CNTs) into polymer matrices. The nanocomposites are prepared using polymer matrices and exhibit a unique combination of properties, most notably, high retention of optical transparency in the visible range (i.e., 400 800 nm), electrical conductivity, and high thermal stability. By appropriate selection of the matrix resin, additional properties such as vacuum ultraviolet radiation resistance, atomic oxygen resistance, high glass transition (T.sub.g) temperatures, and excellent toughness can be attained. The resulting nanocomposites can be used to fabricate or formulate a variety of articles such as coatings on a variety of substrates, films, foams, fibers, threads, adhesives and fiber coated prepreg. The properties of the nanocomposites can be adjusted by selection of the polymer matrix and CNT to fabricate articles that possess high optical transparency and antistatic behavior
Electrically conductive, optically transparent polymer/carbon nanotube composites
The present invention is directed to the effective dispersion of carbon nanotubes (CNTs) into polymer matrices. The nanocomposites are prepared using polymer matrices and exhibit a unique combination of properties, most notably, high retention of optical transparency in the visible range (i.e., 400-800 nm), electrical conductivity, and high thermal stability. By appropriate selection of the matrix resin, additional properties such as vacuum ultraviolet radiation resistance, atomic oxygen resistance, high glass transition (T.sub.g) temperatures, and excellent toughness can be attained. The resulting nanocomposites can be used to fabricate or formulate a variety of articles such as coatings on a variety of substrates, films, foams, fibers, threads, adhesives and fiber coated prepreg. The properties of the nanocomposites can be adjusted by selection of the polymer matrix and CNT to fabricate articles that possess high optical transparency and antistatic behavior
The Dynamical Status of the Cluster of Galaxies 1E0657-56
We present the results of a new spectroscopic and photometric survey of the
hot X-ray cluster 1E0657-56, at z=0.296. We determine the presence of a low
velocity dispersion subcluster, which is offset from the main cluster position
by 0.7 Mpc and about 600 km/s. We determine the virial masses and total
luminosities of the cluster and its subcluster, and solve for the two-body
dynamical model. With additional constraints from the results of the analysis
of the cluster X-ray emission by Markevitch et al. (2001), we find that the
subcluster passed through the cluster centre about 0.15 Gyr ago. Taken at face
value the mass of the subcluster is typical of a loose group. It is however
difficult to establish the pre-merger mass of the colliding system. We provide
tentative evidence that the subcluster is in fact the remnant core of a
moderately massive cluster, stripped by the collision with 1E0657-56. The main
cluster dynamics does not seem to have suffered from this collision. On the
contrary, the cluster X-ray properties seem to have been significantly
affected. We also discuss the effect of the subcluster collision in relation to
starburst events and the cluster radio halo.Comment: Accepted for publication on A&
The insulin A-chain epitope recognized by human T cells is posttranslationally modified
The autoimmune process that destroys the insulin-producing pancreatic β cells in type 1 diabetes (T1D) is targeted at insulin and its precursor, proinsulin. T cells that recognize the proximal A-chain of human insulin were identified recently in the pancreatic lymph nodes of subjects who had T1D. To investigate the specificity of proinsulin-specific T cells in T1D, we isolated human CD4+ T cell clones to proinsulin from the blood of a donor who had T1D. The clones recognized a naturally processed, HLA DR4–restricted epitope within the first 13 amino acids of the A-chain (A1–13) of human insulin. T cell recognition was dependent on the formation of a vicinal disulfide bond between adjacent cysteine residues at A6 and A7, which did not alter binding of the peptide to HLA DR4. CD4+ T cell clones that recognized this epitope were isolated from an HLA DR4+ child with autoantibodies to insulin, and therefore, at risk for T1D, but not from two healthy HLA DR4+ donors. We define for the first time a novel posttranslational modification that is required for T cell recognition of the insulin A-chain in T1D
Classical and quantum: a conflict of interest
We highlight three conflicts between quantum theory and classical general
relativity, which make it implausible that a quantum theory of gravity can be
arrived at by quantising classical gravity. These conflicts are: quantum
nonlocality and space-time structure; the problem of time in quantum theory;
and the quantum measurement problem. We explain how these three aspects bear on
each other, and how they point towards an underlying noncommutative geometry of
space-time.Comment: 15 pages. Published in `Gravity and the quantum' [Essays in honour of
Thanu Padmanabhan on the occasion of his sixtieth birthday] Eds. Jasjeet
Singh Bagla and Sunu Engineer (Springer, 2017
Advancing fish breeding in aquaculture through genome functional annotation
Genomics is increasingly applied in breeding programmes for farmed fish and shellfish species around the world. However, current applications do not include information on genome functional activity, which can enhance opportunities to predict relationships between genotypes and phenotypes and hence increase the accuracy of selection. Here, we review prospects for improving aquaculture breeding practises through the uptake of functional genomics data in light of the EU Horizon 2020 project AQUA-FAANG: ‘Advancing European Aquaculture by Genome Functional Annotation’. This consortium targeted the six major farmed fish species in European aquaculture, producing thousands of functional genomic datasets from samples representing embryos to mature adults of both sexes, and following immunological stimulation. This data was used to catalogue functional activity across the genome of each species, revealing transcribed regions, distinct chromatin states and regulatory elements impacting gene expression. These functional annotations were shared as open data through the Ensembl genome browser using the latest reference genomes for each species. AQUA-FAANG data offers novel opportunities to identify and prioritize causative genetic variants responsible for diverse traits including disease resistance, which can be exploited to enhance selective breeding. Such knowledge and associated resources have the potential to improve sustainability and boost production in aquaculture by accelerating genetic gain for health and robustness to infection, whilst reducing the requirement for animal testing. We further outline directions to advance and leverage genome functional annotation beyond the AQUA-FAANG project. Given the diversity of aquaculture sectors and businesses, the incorporation of functional genomic information into breeding decisions will depend on technological readiness level and scale of operation, with cost-benefit analysis necessary to determine the most profitable approach for each species and production system
Latitudinal dependency of geomagnetic polarity transition durations
Palaeomagnetic records of the Matuyama-Brunhes polarity transition were obtained from seven, low sedimentation rate, deepsea cores from the Pacific Ocean. The cores were taken near the 180° meridian and provide a latitudinal transect of transition records extending from 45.3° N to 33.4° S. Examination of these records suggests that low sedimentation rate cores may not be capable of recording the fine details of transitional field behaviour, but there are indications that these cores may, in fact, provide accurate records of the more general features of the reversal. Most notable of these features is that the duration of the transition is dependent on the site latitude, with durations at mid-latitudes being more than a factor of 2 longer than at equatorial latitudes
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