87 research outputs found
Determination of alpha spectroscopic factors for unbound 17O states
It has been recently suggested that hydrogen ingestion into the helium shell of massive stars could lead to high 13C and 15N excesses when the blast of a core collapse supernova (ccSN) passes through its helium shell. This prediction questions the origin of extremely high 13C and 15N abundances observed in rare presolar SiC grains which is usually attributed to classical novae. In this context the 13N(α,p)16O reaction plays an important role since it is in competition with 13N β+-decay to 13C. As a first step to the determination of the 13N(α,p)16O reaction rate, we present a study aiming at the determination of alpha spectroscopic factors of 17O states which are the analog ones to those in 17F, the compound nucleus of the 13N(α,p)16O reaction
Multi-Donor longitudinal antibody repertoire sequencing reveals the existence of public antibody clonotypes in HIV-1 infection
Characterization of single antibody lineages within infected individuals has provided insights into the development of Env-specific antibodies. However, a systems-level understanding of the humoral response against HIV-1 is limited. Here, we interrogated the antibody repertoires of multiple HIV-infected donors from an infection-naive state through acute and chronic infection using next-generation sequencing. This analysis revealed the existence of “public” antibody clonotypes that were shared among multiple HIV-infected individuals. The HIV-1 reactivity for representative antibodies from an identified public clonotype shared by three donors was confirmed. Furthermore, a meta-analysis of publicly available antibody repertoire sequencing datasets revealed antibodies with high sequence identity to known HIV-reactive antibodies, even in repertoires that were reported to be HIV naive. The discovery of public antibody clonotypes in HIV-infected individuals represents an avenue of significant potential for better understanding antibody responses to HIV-1 infection, as well as for clonotype-specific vaccine development
Gravitational lensing reveals extreme dust-obscured star formation in quasar host galaxies
We have observed 104 gravitationally-lensed quasars at with
Herschel/SPIRE, the largest such sample ever studied. By targeting
gravitational lenses, we probe intrinsic far-infrared (FIR) luminosities and
star formation rates (SFRs) more typical of the population than the extremely
luminous sources that are otherwise accessible. We detect 72 objects with
Herschel/SPIRE and find 66 percent (69 sources) of the sample have spectral
energy distributions (SEDs) characteristic of dust emission. For 53 objects
with sufficiently constrained SEDs, we find a median effective dust temperature
of K. By applying the radio-infrared correlation, we find no
evidence for an FIR excess which is consistent with star-formation-heated dust.
We derive a median magnification-corrected FIR luminosity of
and median SFR of
for 94 quasars with redshifts. We
find percent of our sample have FIR properties similar to typical
dusty star-forming galaxies at and a range of SFRs for our sample as a whole. These results are in line with
current models of quasar evolution and suggests a coexistence of dust-obscured
star formation and AGN activity is typical of most quasars. We do not find a
statistically-significant difference in the FIR luminosities of quasars in our
sample with a radio excess relative to the radio-infrared correlation.
Synchrotron emission is found to dominate at FIR wavelengths for percent
of those sources classified as powerful radio galaxies.Comment: 47 pages, 89 figures, accepted for publication in MNRA
Growth and nutrient concentration of two native forage legumes inoculated with Rhizobium and Mycorrhiza in Missouri, USA
Multi-ancestry transcriptome-wide association analyses yield insights into tobacco use biology and drug repurposing
Most transcriptome-wide association studies (TWASs) so far focus on European ancestry and lack diversity. To overcome this limitation, we aggregated genome-wide association study (GWAS) summary statistics, whole-genome sequences and expression quantitative trait locus (eQTL) data from diverse ancestries. We developed a new approach, TESLA (multi-ancestry integrative study using an optimal linear combination of association statistics), to integrate an eQTL dataset with a multi-ancestry GWAS. By exploiting shared phenotypic effects between ancestries and accommodating potential effect heterogeneities, TESLA improves power over other TWAS methods. When applied to tobacco use phenotypes, TESLA identified 273 new genes, up to 55% more compared with alternative TWAS methods. These hits and subsequent fine mapping using TESLA point to target genes with biological relevance. In silico drug-repurposing analyses highlight several drugs with known efficacy, including dextromethorphan and galantamine, and new drugs such as muscle relaxants that may be repurposed for treating nicotine addiction
From geochemical prospecting to international geochemical mapping: a historical overview
The Addition of Carotenoids as a Means of Maintaining a Uniform Color in Milk as Measured by the Lac-Chrom-Meter
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