The hyperfine transition in light muonic atoms of odd Z

The hyperfine (hf) transition rates for muonic atoms have been re-measured for select light nuclei, using neutron detectors to evaluate the time dependence of muon capture. For $^{19}$F $\Lambda$$_{h}$ = 5.6 (2) $\mu$s$^{-1}$ for the hf transition rate, a value which is considerably more accurate than previous measurements. Results are also reported for Na, Al, P, Cl, and K; that result for P is the first positive identification.Comment: 12 pages including 5 tables and 4 figures, RevTex, submitted to Phys. Rev.

Nucleotide variation, haplotype structure, and association with end-stage renal disease of the human interleukin-1 gene cluster

A dense gene-based SNP map was constructed across a 360-kb region containing the interleukin-1 gene cluster (IL1A, IL1B, and IL1RN), focusing on IL1RN. In total, 95 polymorphisms were confirmed or identified primarily by direct sequencing. Polymorphisms were precisely mapped to completed BAC and genomic sequences spanning this region. The polymorphisms were typed in 443 case-control subjects from Caucasian and African American groups. Consecutive pair-wise marker linkage disequilibrium was not strictly correlated with distance and ranged from D′ = 0.0079 to 1.000 and D′ = 0.0521 to 1.0000 in Caucasians and African Americans, respectively. Single markers and haplotypes in IL1 cluster genes were evaluated for association with end-stage renal disease (ESRD). Eleven SNPs show some evidence of association with ESRD, with the strongest associations in two IL1A variants, one SNP, rs1516792-3, in intron 5 (p = 0.0015) and a 4-bp insertion/deletion within the 3′UTR, rs16347-2 (p = 0.0024), among African Americans with non-T2DM-associated ESRD

The application of X-ray micro Computed Tomography imaging for tracing particle movement in soil

Despite significant advances in recent years in the application of sensing and imaging technologies to the study of the hydraulic behaviour of soils, our understanding of how solutes and particulate matter move through soil is still limited and often based on idealised soil structures. The aim of this work was to use an appropriate proxy material, in this case (Decabromodiphenyl ether (DBDE)), to represent 1–2 μm sized chemical particles, frequently used in agricultural practices, in order to trace their spatial and temporal movement through a soil column. X-ray Computed Tomography (CT) was employed to map the 3D pore geometry and facilitate visualization of the concentration distribution of the highly X-ray attenuating proxy material as it was applied and subsequently leached through the soil over a 5 hour period. Simultaneously the soil eluate was collected from the bottom of each column and the concentration of proxy material measured using gas chromatography to compare with the imaged data. The method developed for visualizing the tracer material in 3D at the pore-scale was successful. The results demonstrated that the tracer material initially moved rapidly through the upper portion of the soil but subsequently became immobile, despite repeated elution with water as confirmed by imagery. Similar concentrations to those applied to the soil surface were not recorded at any point in time towards the bottom of the soil column. By visualizing the DBDE distribution in 3D it was possible to correlate the highest concentrations of the tracer material with the location of the smaller size pores (i.e. mesopores). Dynamic X-ray CT imaging of tracer materials has considerable potential as a proxy for the visualization of particulate agricultural chemicals that will assist with understanding how their transport behaviour varies both spatially and temporally

Late Winter Biogeochemical Conditions Under Sea Ice in the Canadian High Arctic

With the Arctic summer sea-ice extent in decline, questions are arising as to how changes in sea-ice dynamics might affect biogeochemical cycling and phenomena such as carbon dioxide (CO2) uptake and ocean acidification. Recent field research in these areas has concentrated on biogeochemical and CO2 measurements during spring, summer or autumn, but there are few data for the winter or winter–spring transition, particularly in the High Arctic. Here, we present carbon and nutrient data within and under sea ice measured during the Catlin Arctic Survey, over 40 days in March and April 2010, off Ellef Ringnes Island (78° 43.11′ N, 104° 47.44′ W) in the Canadian High Arctic. Results show relatively low surface water (1–10 m) nitrate (<1.3 µM) and total inorganic carbon concentrations (mean±SD=2015±5.83 µmol kg−1), total alkalinity (mean±SD=2134±11.09 µmol kg−1) and under-ice pCO2sw (mean±SD=286±17 µatm). These surprisingly low wintertime carbon and nutrient conditions suggest that the outer Canadian Arctic Archipelago region is nitrate-limited on account of sluggish mixing among the multi-year ice regions of the High Arctic, which could temper the potential of widespread under-ice and open-water phytoplankton blooms later in the season

An Integrated TCGA Pan-Cancer Clinical Data Resource to Drive High-Quality Survival Outcome Analytics

For a decade, The Cancer Genome Atlas (TCGA) program collected clinicopathologic annotation data along with multi-platform molecular profiles of more than 11,000 human tumors across 33 different cancer types. TCGA clinical data contain key features representing the democratized nature of the data collection process. To ensure proper use of this large clinical dataset associated with genomic features, we developed a standardized dataset named the TCGA Pan-Cancer Clinical Data Resource (TCGA-CDR), which includes four major clinical outcome endpoints. In addition to detailing major challenges and statistical limitations encountered during the effort of integrating the acquired clinical data, we present a summary that includes endpoint usage recommendations for each cancer type. These TCGA-CDR findings appear to be consistent with cancer genomics studies independent of the TCGA effort and provide opportunities for investigating cancer biology using clinical correlates at an unprecedented scale. Analysis of clinicopathologic annotations for over 11,000 cancer patients in the TCGA program leads to the generation of TCGA Clinical Data Resource, which provides recommendations of clinical outcome endpoint usage for 33 cancer types

Strong one-neutron emission from two-neutron unbound states in β decays of the r -process nuclei Ga 86,87

β-delayed one-neutron and two-neutron branching ratios (P1n and P2n) have been measured in the decay of A=84 to 87 Ga isotopes at the Radioactive-Isotope Beam Factory (RIBF) at the RIKEN Nishina Center using a high-efficiency array of He3 neutron counters (BRIKEN). Two-neutron emission was observed in the decay of Ga84,85,87 for the first time and the branching ratios were measured to be P2n=1.6(2)%,1.3(2)%, and 10.2(28)stat(5)sys%, respectively. One-neutron branching ratio of Ga87(P1n=81(9)stat(8)sys%) and half-life of 29(4) ms were measured for the first time. The branching ratios of Ga86 were also measured to be P1n=74(2)stat(8)sys% and 16.2(9)stat(6)sys% with better precision than a previous study. The observation that P1n>P2n for both Ga86,87 was unexpected and is interpreted as a signature of dominating one-neutron emission from the two-neutron unbound excited states in Ge86,87. In order to interpret the experimental results, shell-model and Hauser-Feshbach statistical model calculations of delayed particle and γ-ray emission probabilities were performed. This model framework reproduces the experimental results. The shell model alone predicts P2n significantly larger than P1n for the Ga87 decay, and it is necessary to invoke a statistical description to successfully explain the observation that P1n>P2n. Our new results demonstrate the relevance and importance of a statistical description of neutron emission for the prediction of the decay properties of multineutron emitters and that it must be included in the r-process modeling

Network structure of vertebrate scavenger assemblages at the global scale: drivers and ecosystem functioning implications

publishedVersio

Commissioning of the BRIKEN detector for the measurement of very exotic β-delayed neutron emitters

A new detection system has been installed at the RIKEN Nishina Center (Japan) to investigate decay properties of very neutron-rich nuclei. The setup consists of three main parts: a moderated neutron counter, a detection system sensitive to the implantation and decay of radioactive ions, and γ-ray detectors. We describe here the setup, the commissioning experiment and some selected results demonstrating its performance for the measurement of half-lives and β-delayed neutron emission probabilities. The methodology followed in the analysis of the data is described in detail. Particular emphasis is placed on the correction of the accidental neutron background