1,553 research outputs found
Mediterranean spreading of the bicolor purse oyster, Isognomon bicolor, and the chicken trigger, Malleus sp., vs. the Lessepsian prejudice
The introduction rate of alien species in the Mediterranean Sea is rapidly growing, and their taxonomical identification is increasingly challenging. This uncertain identification often leads to an incorrect estimation of the number of alien species, their route of introduction, and their potential negative effects. This is particularly true for some bivalves, which are characterized by high variation in their shells, resulting in uncertain morphological identification. This is the case for two alien bivalves, i.e., an Isognomonidae and a Malleidae species, both characterized by confused historical colonization records in the Mediterranean Sea, misidentifications, and controversial and changing nomenclatures that have insofar negatively affected our knowledge on their geographical distributions. In this respect, molecular approaches provide a strategy that is especially useful when traditional taxonomy fails, and DNA barcoding is a powerful and well-known tool to obtain reliable identifications through efficient molecular markers. In this work, we used the 16S rRNA marker to assess the preliminary identification of Isognomon sp. and Malleus sp. specimens from different localities in the Southern Mediterranean Sea. Bayesian inference (BI) and maximum likelihood (ML) methods were applied to test the monophyly of the phylogenetic linages and to clarify their taxonomic positions, allowing a complete overview of the colonization and spreading of these two alien bivalves in the Mediterranean Sea. In particular, the Isognomon sp. specimens were identified as the Atlantic I. bicolor, highlighting that previously suggested invasive migration patterns, (i.e., the Lessepsian migration), must be reconsidered with stronger critical attention in light of currently occurring global changes
The Haunted Halos of Andromeda and Triangulum: A panorama of galaxy formation in action
We present a deep photometric survey of M31, conducted with the CFHT and INT,
covering the inner 50 kpc of the galaxy, the Southern quadrant out to 150 kpc,
and extending to M33. This is the first systematic panoramic study of this very
outermost region of galaxies. We detect several streams and other large-scale
structures, and two new dwarf galaxies: And XV and XVI. The discovery of
substructure on the minor axis, together with the fact that the light profile
between 0.5 < R < 1.3 follows the exponential ``extended disk'', is
particularly important in shedding light on the mixed and sometimes conflicting
results reported in previous studies. Underlying the substructures lies a
faint, metal-poor, smooth and extremely extended halo, reaching out to at least
150 kpc. The smooth halo component in M31 has a profile that can be fit with a
Hernquist model of immense scale radius ~55 kpc, almost a factor of 4 larger
than theoretical predictions. Alternatively a power-law with exponent -1.91 +/-
0.11 can be fit to the profile. The total luminosity of this structure is
similar to that of the halo of the Milky Way. This vast, smooth, underlying
halo is reminiscent of a classical monolithic model and completely unexpected
from modern galaxy formation models. M33 is also found to have an extended
metal-poor halo component, which can be fit with a Hernquist model also of
scale radius ~55 kpc. These extended slowly-decreasing halos will provide a
challenge and strong constraints for further modeling. [Abridged]Comment: 38 pages, 55 figures, submitted to ApJ. High resolution version
available at http://palantir.u-strasbg.fr/~ibata/pdf/0704.1318.pdf Please do
not bother with the astro-ph version - the figures are devoid of informatio
Measurement of the internal magnetic field of plasmas using an alpha particle source
The internal magnetic fields of plasmas can be measured under certain conditions from the integrated v x B deflection of MeV alpha particles emitted by a small radioactive source. This alpha source and large-area alpha particle detector would be located inside the vacuum vessel but outside the plasma. Alphas with a typical energy of 5.5 MeV (241Am) can reach the center of almost all laboratory plasmas and magnetic fusion devices, so this method can potentially determine the q(r) profile of tokamaks or STs. Orbit calculations, background evaluations, and conceptual designs for such a vxB (or ''AVB'') detector are described
Designer cell signal processing circuits for biotechnology
Microorganisms are able to respond effectively to diverse signals from their environment and internal metabolism owing to their inherent sophisticated information processing capacity. A central aim of synthetic biology is to control and reprogramme the signal processing pathways within living cells so as to realise repurposed, beneficial applications ranging from disease diagnosis and environmental sensing to chemical bioproduction. To date most examples of synthetic biological signal processing have been built based on digital information flow, though analogue computing is being developed to cope with more complex operations and larger sets of variables. Great progress has been made in expanding the categories of characterised biological components that can be used for cellular signal manipulation, thereby allowing synthetic biologists to more rationally programme increasingly complex behaviours into living cells. Here we present a current overview of the components and strategies that exist for designer cell signal processing and decision making, discuss how these have been implemented in prototype systems for therapeutic, environmental, and industrial biotechnological applications, and examine emerging challenges in this promising field
The new Checklist of the Italian Fauna: marine Mollusca.
The mollusc fauna of the Mediterranean Sea is still considered as the best-known marine mollusc fauna in the world. The previous modern checklists of marine Mollusca were produced by joint teams of amateurs and professionals. During the last years the Italian Society of Malacology (Società Italiana di Malacologia – S.I.M.) maintained an updated version of the Mediterranean checklist, that served as the backbone for the development of the new Italian checklist. According to the current version (updated on April 1st, 2021), 1,777 recognised species of marine molluscs are present in the Italian Economic Exclusive Zone, including also the Tyrrhenian coasts of Corsica and the continental shelf of the Maltese archipelago. The new checklist shows an increase of 17% of the species reported in the 1995 Checklist. This is largely (yet not solely) due to the new wave of studies based on Integrative Taxonomy approaches. A total of 135 species (7.6%) are strictly endemic to the Italian waters; 44 species (2.5%) are alien and correspond to the 28% of the Mediterranean alien marine molluscs. All eight extant molluscan classes are represented. The families represented in the Italian fauna are 307, an increase of 14.6% from the first checklist, partly due to new records and partly to new phylogenetic systematics. Compared with the whole Mediterranean malacofauna, the Italian component represents 71% in species and 61% in families, which makes it a very remarkable part of the Mediterranean fauna
A novel plant protein-disulfide isomerase involved in the oxidative folding of cystine knot defense proteins
We have isolated a protein-disulfide isomerase (PDI) from Oldenlandia affinis (OaPDI), a coffee family ( Rubiaceae) plant that accumulates knotted circular proteins called cyclotides. The novel plant PDI appears to be involved in the biosynthesis of cyclotides, since it co-expresses and interacts with the cyclotide precursor protein Oak1. OaPDI exhibits similar isomerase activity but greater chaperone activity than human PDI. Since domain c of OaPDI is predicted to have a neutral pI, we conclude that this domain does not have to be acidic in nature for PDI to be a functional chaperone. Its redox potential of -157 +/- 4 mV supports a role as a functional oxidoreductase in the plant. The mechanism of enzyme-assisted folding of plant cyclotides was investigated by comparing the folding of kalata B1 derivatives in the presence and absence of OaPDI. OaPDI dramatically enhanced the correct oxidative folding of kalata B1 at physiological pH. A detailed investigation of folding intermediates suggested that disulfide isomerization is an important role of the new plant PDI and is an essential step in the production of insecticidal cyclotides
Heart failure subtypes and thromboembolic risk in patients with atrial fibrillation::The PREFER in AF - HF substudy
BACKGROUND AND OBJECTIVES: To assess thromboembolic and bleeding risks in patients with heart failure (HF) and atrial fibrillation (AF) according to HF type. METHODS: We analyzed 6170 AF patients from the Prevention of thromboembolic events - European Registry in Atrial Fibrillation (PREFER in AF), and categorized patients into: HF with reduced left-ventricular ejection fraction (HFrEF; LVEF60%), and no HF. Outcomes were ischemic stroke, major adverse cardiovascular and cerebral events (MACCE) and major bleeding occurring within 1-year. RESULTS: The annual incidence of stroke was linearly and inversely related to LVEF, increasing by 0.054% per each 1% of LVEF decrease (95% CI: 0.013%-0.096%; p=0.031). Patients with HFHpEF had the highest CHA2DS2-VASc score, but significantly lower stroke incidence than other HF groups (0.65%, compared to HFLpEF 1.30%; HFmrEF 1.71%; HFrEF 1.75%; trend p=0.014). The incidence of MACCE was also lower in HFHpEF (2.0%) compared to other HF groups (range: 3.8-4.4%; p=0.001). Age, HF type, and NYHA class were independent predictors of thromboembolic events. Conversely, major bleeding did not significantly differ between groups (p=0.168). CONCLUSION: Our study in predominantly anticoagulated patients with AF shows that, reduction in LVEF is associated with higher thromboembolic, but not higher bleeding risk. HFHpEF is a distinct and puzzling group, featuring the highest CHA2DS2-VASc score but the lowest residual risk of thromboembolic events, which warrants further investigation
Antithrombotic management and outcomes of patients with atrial fibrillation treated with NOACs early at the time of market introduction:Main results from the PREFER in AF Prolongation Registry
International audienceAbstract The management of patients with atrial fibrillation (AF) has rapidly changed with increasing use of non-vitamin K antagonist oral anticoagulants (NOACs) and changes in the use of rhythm control therapy. The prevention of thromboembolic events European Registry in Atrial Fibrillation Prolongation Registry (PREFER Prolongation) enrolled consecutive patients with AF on NOACs between 2014 and 2016 in a multicentre, prospective, observational study with one-year follow-up, focusing on the time of introduction of NOACs. Overall, 3783 patients were enrolled, with follow-up information available in 3223 (85%). Mean age was 72.2 ± 9.4 years, 40% were women, mean CHA 2 DS 2 VASc score was 3.4 ± 1.6, and 2587 (88.6%) had a CHA 2 DS 2 VASc score ≥ 2. Rivaroxaban was used in half of patients, and dabigatran and apixaban were used in about a quarter of patients each; edoxaban was not available for use in Europe at the time. Major cardiovascular event rate was low: serious events occurred in 74 patients (84 events, 2%), including 24 strokes (1%), 62 major bleeds (2%), of which 30 were life-threatening (1%) and 3 intracranial (0.1%), and 28 acute coronary syndromes (1%). Mortality was 2%. Antiarrhythmic drugs were used in about 50% of patients, catheter ablation in 5%. Adverse events were low in this contemporary European cohort of unselected AF patients treated with NOACs already at the time of their first introduction, despite high thromboembolic risk
Measurement of the cross-section and charge asymmetry of bosons produced in proton-proton collisions at TeV with the ATLAS detector
This paper presents measurements of the and cross-sections and the associated charge asymmetry as a
function of the absolute pseudorapidity of the decay muon. The data were
collected in proton--proton collisions at a centre-of-mass energy of 8 TeV with
the ATLAS experiment at the LHC and correspond to a total integrated luminosity
of 20.2~\mbox{fb^{-1}}. The precision of the cross-section measurements
varies between 0.8% to 1.5% as a function of the pseudorapidity, excluding the
1.9% uncertainty on the integrated luminosity. The charge asymmetry is measured
with an uncertainty between 0.002 and 0.003. The results are compared with
predictions based on next-to-next-to-leading-order calculations with various
parton distribution functions and have the sensitivity to discriminate between
them.Comment: 38 pages in total, author list starting page 22, 5 figures, 4 tables,
submitted to EPJC. All figures including auxiliary figures are available at
https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2017-13
CATCHprofiles: Clustering and Alignment Tool for ChIP Profiles
Chromatin Immuno Precipitation (ChIP) profiling detects in vivo protein-DNA binding, and has revealed a large combinatorial complexity in the binding of chromatin associated proteins and their post-translational modifications. To fully explore the spatial and combinatorial patterns in ChIP-profiling data and detect potentially meaningful patterns, the areas of enrichment must be aligned and clustered, which is an algorithmically and computationally challenging task. We have developed CATCHprofiles, a novel tool for exhaustive pattern detection in ChIP profiling data. CATCHprofiles is built upon a computationally efficient implementation for the exhaustive alignment and hierarchical clustering of ChIP profiling data. The tool features a graphical interface for examination and browsing of the clustering results. CATCHprofiles requires no prior knowledge about functional sites, detects known binding patterns “ab initio”, and enables the detection of new patterns from ChIP data at a high resolution, exemplified by the detection of asymmetric histone and histone modification patterns around H2A.Z-enriched sites. CATCHprofiles' capability for exhaustive analysis combined with its ease-of-use makes it an invaluable tool for explorative research based on ChIP profiling data
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