288 research outputs found
The missing Rheic Ocean magmatic arcs: Provenance analysis of Late Paleozoic
Early Carboniferous turbiditic sedimentary rocks in synorogenic basins located on both sides of the Rheic suture in
SW Iberiawere studied for provenance analysis. An enigmatic feature of this suture, which resulted from closure
of the Rheic Ocean with the amalgamation of Pangea in the Late Carboniferous, is that there are no recognizable
mid- to Late Devonian subduction-related magmatic rocks,which should have been generated during the process
of subduction, on either side of it. UâPb LAâICP-MS geochronology of detrital zircons from Early Carboniferous
turbidites in the vicinity of the Rheic suture in SW Iberia, where it separates the OssaâMorena Zone (with
Gondwana continental basement) to the north from the South Portuguese Zone (with unknown/Meguma?
continental basement) to the south, reveals the abundance of mid- to Late Devonian (51â81%) and Early
Carboniferous (13â25%) ages. The Cabrela andMĂ©rtola turbidites of the OssaâMorena and South Portuguese
zones, respectively, are largely devoid of older zircons, differing from the age spectra of detrital zircons in
the oldest (Late Devonian) strata in the underlying South Portuguese Zone, which contain abundant Cambrian
and Neoproterozoic ages. Mid- to Late Devonian zircons in the Cabrela Formation (age cluster at c. 391 Ma,
EifelianâGivetian transition) and MĂ©rtola Formation (age clusters at c. 369 Ma and at c. 387 Ma, Famennian
and Givetian respectively) are attributable to a source terrane made up of magmatic rocks with a simple
geological history lacking both multiple tectonic events and older continental basement. The terrane capa-
ble of sourcing sediments dispersed on both sides of the suture is interpreted to have been completely re-
moved by erosion in SW Iberia. Given that closure of the Rheic Ocean required subduction of its oceanic
lithosphere and the absence of significant arc magmatism on either side of the Rheic suture, we suggest:
1) the source of the zircons in the SW Iberia basins was a short-lived Rheic ocean magmatic arc, and
2) given the lack of older zircons in the SW Iberia basins, this short-lived arc was probably developed
in an intra-oceanic environment
Genetic Homogeneity of the Invasive Lionfish Across the Northwestern Atlantic and the Gulf of Mexico Based On Single Nucleotide Polymorphisms
Despite the devastating impact of the lionfish (Pterois volitans) invasion on NW Atlantic ecosystems, little genetic information about the invasion process is available. We applied Genotyping by Sequencing techniques to identify 1,220 single nucleotide polymorphic sites (SNPs) from 162 lionfish samples collected between 2013 and 2015 from two areas chronologically identified as the first and last invaded areas in US waters: the east coast of Florida and the Gulf of Mexico. We used population genomic analyses, including phylogenetic reconstruction, Bayesian clustering, genetic distances, Discriminant Analyses of Principal Components, and coalescence simulations for detection of outlier SNPs, to understand genetic trends relevant to the lionfishâs long-term persistence. We found no significant differences in genetic structure or diversity between the two areas (FST p-valuesâ\u3eâ0.01, and t-test p-valuesâ\u3eâ0.05). In fact, our genomic analyses showed genetic homogeneity, with enough gene flow between the east coast of Florida and Gulf of Mexico to erase previous signals of genetic divergence detected between these areas, secondary spreading, and bottlenecks in the Gulf of Mexico. These findings suggest rapid genetic changes over space and time during the invasion, resulting in one panmictic population with no signs of divergence between areas due to local adaptation
The serum proteome of Atlantic salmon, Salmo salar, during pancreas disease (PD) following infection with salmonid alphavirus subtype 3 (SAV3)
Salmonid alphavirus is the aetological agent of pancreas disease (PD) in marine Atlantic salmon, Salmo salar, and rainbow trout, Oncorhynchus mykiss, with most outbreaks in Norway caused by SAV subtype 3 (SAV3). This atypical alphavirus is transmitted horizontally causing a significant economic impact on the aquaculture industry. This histopathological and proteomic study, using an established cohabitational experimental model, investigated the correlation between tissue damage during PD and a number of serum proteins associated with these pathologies in Atlantic salmon. The proteins were identified by two-dimensional electrophoresis, trypsin digest and peptide MS/MS fingerprinting. A number of humoral components of immunity which may act as biomarkers of the disease were also identified. For example, creatine kinase, enolase and malate dehydrogenase serum concentrations were shown to correlate with pathology during PD. In contrast, hemopexin, transferrin, and apolipoprotein, amongst others, altered during later stages of the disease and did not correlate with tissue pathologies. This approach has given new insight into not only PD but also fish disease as a whole, by characterisation of the protein response to infection, through pathological processes to tissue recovery.
Biological significance:
Salmonid alphavirus causes pancreas disease (PD) in Atlantic salmon, Salmo salar, and has a major economic impact on the aquaculture industry. A proteomic investigation of the change to the serum proteome during PD has been made with an established experimental model of the disease. Serum proteins were identified by two-dimensional electrophoresis, trypsin digest and peptide MS/MS fingerprinting with 72 protein spots being shown to alter significantly over the 12 week period of the infection. The concentrations of certain proteins in serum such as creatine kinase, enolase and malate dehydrogenase were shown to correlate with tissue pathology while other proteins such as hemopexin, transferrin, and apolipoprotein, altered in concentration during later stages of the disease and did not correlate with tissue pathologies. The protein response to infection may be used to monitor disease progression and enhance understanding of the pathology of PD
Limits on Fast Radio Bursts and other transient sources at 182 MHz using the Murchison Widefield Array
A High Statistics Search for Ultra-High Energy Gamma-Ray Emission from Cygnus X-3 and Hercules X-1
We have carried out a high statistics (2 Billion events) search for
ultra-high energy gamma-ray emission from the X-ray binary sources Cygnus X-3
and Hercules X-1. Using data taken with the CASA-MIA detector over a five year
period (1990-1995), we find no evidence for steady emission from either source
at energies above 115 TeV. The derived upper limits on such emission are more
than two orders of magnitude lower than earlier claimed detections. We also
find no evidence for neutral particle or gamma-ray emission from either source
on time scales of one day and 0.5 hr. For Cygnus X-3, there is no evidence for
emission correlated with the 4.8 hr X-ray periodicity or with the occurrence of
large radio flares. Unless one postulates that these sources were very active
earlier and are now dormant, the limits presented here put into question the
earlier results, and highlight the difficulties that possible future
experiments will have in detecting gamma-ray signals at ultra-high energies.Comment: 26 LaTeX pages, 16 PostScript figures, uses psfig.sty to be published
in Physical Review
The Murchison Widefield Array Transients Survey (MWATS):A search for low-frequency variability in a bright Southern hemisphere sample
Acquired vesicovaginal fistula secondary to ovariohysterectomy in a bitch: a case report
CR-12INTRACYSTIC INTERFERON-ALPHA IN PAEDIATRIC CRANIOPHARYNGIOMA PATIENTS: AN INTERNATIONAL MULTI-CENTRE ASSESSMENT ON BEHALF OF SIOP-E AND ISPN
New insights into the genetic etiology of Alzheimer's disease and related dementias
Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE Δ4 allele
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