1,249 research outputs found
Advanced Compton Telescope Designs and SN Science
The Advanced Compton Telescope (ACT) has been suggested to be the optimal
next-generation instrument to study nuclear gamma-ray lines. In this work, we
investigate the potential of three hypothetical designs of the ACT to perform
SN science. We provide estimates of 1) the SN detection rate, 2) the SN Ia
discrimination rate, and 3) which gamma-ray lines would be detected from
specific supernova remnants. We find that the prompt emission from a SN Ia is
such that it is unlikely that one would be within the range that an
INTERMEDIATE ACT would be able to distinguish between explosion scenarios,
although such an instrument would detect a handful of SNRs.
We further find that the SUPERIOR ACT design would be a truly breakthrough
instrument for SN science. By supplying these estimates, we intend to assist
the gamma-ray astrophysics community in deciding the course of the next decade
of gamma-ray SN science.Comment: 10 pages, accepted for publication in New astronomy Reviews
(Astronomy with Radioactivities III
Gamma-Rays as Probes for the Multi-Dimensionality of Type Ia Supernovae
We present -ray spectra for a set of Type Ia supernovae models. Our
study is based on a detailed Monte Carlo transport scheme for both spherical
and full 3-D geometries. Classical and new challenges of the ray
astronomy are addressed. We find that -rays are very suitable to
reveal the structure of the envelope and, thus, they allow to probe properties
of the nuclear burning front and the progenitor, namely its central density and
global asphericities. The potential problems are discussed for the quantitative
comparison between theoretical and observed line fluxes during the first few
months after the explosion.Comment: in Astronomy with Radioactivities,ed.R.Diehl,SpaceScienceRev.,in
pres
Weak in Space, Log in Time Improvement of the Lady{\v{z}}enskaja-Prodi-Serrin Criteria
In this article we present a Lady{\v{z}}enskaja-Prodi-Serrin Criteria for
regularity of solutions for the Navier-Stokes equation in three dimensions
which incorporates weak norms in the space variables and log improvement
in the time variable.Comment: 14 pages, to appea
Calcineurin Selectively Docks with the Dynamin Ixb Splice Variant to Regulate Activity-dependent Bulk Endocytosis
Depolarization of nerve terminals stimulates rapid dephosphorylation of two isoforms of dynamin I (dynI), mediated by the calcium-dependent phosphatase calcineurin (CaN). Dephosphorylation at the major phosphorylation sites Ser-774/778 promotes a dynI-syndapin I interaction for a specific mode of synaptic vesicle endocytosis called activity-dependent bulk endocytosis (ADBE). DynI has two main splice variants at its extreme C terminus, long or short (dynIxa and dynIxb) varying only by 20 (xa) or 7 (xb) residues. Recombinant GST fusion proteins of dynIxa and dynIxb proline-rich domains (PRDs) were used to pull down interacting proteins from rat brain nerve terminals. Both bound equally to syndapin, but dynIxb PRD exclusively bound to the catalytic subunit of CaNA, which recruited CaNB. Binding of CaN was increased in the presence of calcium and was accompanied by further recruitment of calmodulin. Point mutations showed that the entire C terminus of dynIxb is a CaN docking site related to a conserved CaN docking motif (PXIXI(T/S)). This sequence is unique to dynIxb among all other dynamin variants or genes. Peptide mimetics of the dynIxb tail blocked CaN binding in vitro and selectively inhibited depolarization-evoked dynI dephosphorylation in nerve terminals but not of other dephosphins. Therefore, docking to dynIxb is required for the regulation of both dynI splice variants, yet it does not regulate the phosphorylation cycle of other dephosphins. The peptide blocked ADBE, but not clathrin-mediated endocytosis of synaptic vesicles. Our results indicate that Ca(2+) influx regulates assembly of a fully active CaN-calmodulin complex selectively on the tail of dynIxb and that the complex is recruited to sites of ADBE in nerve terminals
Engaging with diverse audiences to raise awareness about childhood eczema:reflections from two community events
Accelerated protein synthesis via one–pot ligation–deselenization chemistry
Peptide ligation chemistry has revolutionized protein science by facilitating access to synthetic proteins. Here, we describe the development of additive-free ligation-deselenization chemistry at β-selenoaspartate and γ-selenoglutamate that enables the generation of native polypeptide products on unprecedented timescales. The deselenization step is chemoselective in the presence of unprotected selenocysteine, which is highlighted in the synthesis of selenoprotein K. The power of the methodology is also showcased through the synthesis of three tick-derived thrombin-inhibiting proteins, each of which were assembled, purified, and isolated for biological assays within a few hours. The methodology described here should serve as a powerful means of accessing synthetic proteins, including therapeutic leads, in the future
Proteomic Analysis of the Cell Cycle of Procylic FormTrypanosoma brucei
We describe a single-step centrifugal elutriation method to produce synchronous G1-phase procyclic trypanosomes at a scale amenable for proteomic analysis of the cell cycle. Using ten-plex tandem mass tag (TMT) labelling and mass spectrometry (MS)-based proteomics technology, the expression levels of 5,325 proteins were quantified across the cell cycle in this parasite. Of these, 384 proteins were classified as cell-cycle regulated and subdivided into nine clusters with distinct temporal regulation. These groups included many known cell cycle regulators in trypanosomes, which validates the approach. In addition, we identify 40 novel cell cycle regulated proteins that are essential for trypanosome survival and thus represent potential future drug targets for the prevention of trypanosomiasis. Through cross-comparison to the TrypTag endogenous tagging microscopy database, we were able to validate the cell-cycle regulated patterns of expression for many of the proteins of unknown function detected in our proteomic analysis. A convenient interface to access and interrogate these data is also presented, providing a useful resource for the scientific community. Data are available via ProteomeXchange with identifier PXD008741
Phase II Study of Vinorelbine Plus Trastuzumab in HER2 Overexpressing Metastatic Breast Cancer Pretreated with Anthracyclines and Taxanes
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