Seasonal cycling of sulfur and iron in porewaters of a Delaware salt marsh

An extensive pore water data set has been gathered in the Great Marsh, Delaware over various seasons, salinities, and tides. The data all point to a complimentary redox cycle for sulfur and iron which operates seasonally and tidally. Surface oxidizing conditions prevail in summer, with more reducing conditions at depth during the winter. During the spring tides which flood the marsh, pyrite oxidation occurs releasing excess dissolved iron (II) and sulfate to the porewaters, and precipitating authigenic solid iron phases. The redox conditions in the porewaters of the upper zone during the summer is poised between mildly oxidizing and mildly reducing conditions as shown by pE calculations. This redox environment and intermediate iron-sulfur redox species may be important for the stimulation of plant growth (photosynthesis) and sustenance of a viable microbial community (heterotrophy and chemoautropy)

On the Fractional Solubillity of Copper in Marine Aerosols: Toxicity of Aeolian Copper Revisited

Paytan et al. (2009) argue that the atmospheric deposition of aerosols lead to copper concentrations that are potentially toxic to marine phytoplankton in a large area of tropical and subtropical North Atlantic Ocean. A key assumption in their model is that all marine aerosols (mineral dust and anthropogenic particles) have a high (40%) fractional solubility of copper. Our data show that the fractional solubility of copper for Saharan dust over the Sargasso Sea and Bermuda is significantly lower (1-7%). In contrast, anthropogenic aerosols with non-Saharan sources have significantly higher values (10-100%). Hence, the potential Cu toxicity in the tropical and subtropical North Atlantic should be re-estimated, given the low fractional solubility of Cu in the Saharan dust that dominates aerosol deposition to this region

Scavenging, cycling and removal fluxes of 210Po and 210Pb at the Bermuda time-series study site

Author Posting. © The Author(s), 2012. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 93 (2013):108–118, doi:10.1016/j.dsr2.2013.01.005.Quantifying relative affinities of Po and Pb in different populations of marine particulate matter is of great importance in utilizing 210Po as a tracer for carbon cycling. We collected and analyzed water samples for the concentrations of dissolved and total 210Po and 30 210Pb from the upper 600 m of the water column at Bermuda Time-series Study site (September 1999 to September 2000) to investigate their seasonality of concentrations and their activity ratio (210Po/210Pb activity ratio, AR). Sinking particles collected in sediment traps at depths of 500 m, 1500 m, and 3200 m from the Oceanic Flux Program (OFP) time-series sediment traps were analyzed over a period of 12 months (May 1999 to May 2000). The objective was to compare the deficiencies of 210Po with respect to 210Pb in the water column to that measured in the sediment traps and to assess the relative affinities of Po and Pb with different particle pools. Inventories of 210Po in the upper 500 m water column varied by a factor of 2, indicating seasonal variations of particulate flux dominated the removal of 210Po. The 210Po/210Pb ARs in the dissolved phase were generally less than the secular equilibrium value (1.0) in the upper 600 m, while were generally greater than 1.0 in the particulate phase, indicating higher removal rates of 210Po relative to 210Pb by particulate matter. The measured fluxes of 210Po and 210Pb in the 500 m, 1500 m, and 3200 m traps increased with depth, while the 210Po/210Pb ARs decreased with depth except from May-August 1999. From the measured fluxes of 210Po and 210Pb at these three traps and the concentrations of 210Po and 210Pb in the water column, this region appears to be a sink for 210Pb which is likely brought-in by lateral advection.GHH’s sabbatical leave was supported by Korea Ocean Research and Development Institute (renamed as Korea Institute of Ocean Science and Technology) (PG47900 and PE98742). The Oceanic Flux Program has been supported since inception by the NSF Chemical Oceanography Program, most recently by grants OCE-0325627/0509602, OCE-0623505 and OCE-0927098. Partial support in writing this manuscript was supported by OCE-0961351 (MB)

Efficacy and Safety of Umeclidinium Added to Fluticasone Propionate/Salmeterol in Patients with COPD : Results of Two Randomized, Double-Blind Studies

Combinations of drugs with distinct and complementary mechanisms of action may offer improved efficacy in the treatment of chronic obstructive pulmonary disease (COPD). In two 12-week, double-blind, parallel-group studies, patients with COPD were randomized 1:1:1 to once-daily umeclidinium (UMEC; 62.5 μg and 125 μg) or placebo (PBO), added to twice-daily fluticasone propionate/salmeterol (FP/SAL; 250/50 μg). In both studies, the primary efficacy measure was trough forced expiratory volume in 1 second (FEV) at Day 85. Secondary endpoints were weighted-mean (WM) FEV over 0-6 hours post-dose (Day 84) and rescue albuterol use. Health-related quality of life outcomes (St. George's Respiratory Questionnaire [SGRQ] and COPD assessment test [CAT]) were also examined. Safety was assessed throughout. Both UMEC+FP/SAL doses provided statistically significant improvements in trough FEV (Day 85: 0.127-0.148 L) versus PBO+FP/SAL. Similarly, both UMEC+FP/SAL doses provided statistically-significant improvements in 0-6 hours post-dose WM FEV versus PBO+FP/SAL (Day 84: 0.144-0.165 L). Rescue use over Weeks 1-12 decreased with UMEC+FP/SAL in both studies versus PBO+FP/SAL (Study 1, 0.3 puffs/day [both doses]; Study 2, 0.5 puffs/day [UMEC 125+FP/SAL]). Decreases from baseline in CAT score were generally larger for both doses of UMEC+FP/SAL versus PBO+FP/SAL (except for Day 84 Study 2). In Study 1, no differences in SGRQ score were observed between UMEC+FP/SAL and PBO+FP/SAL; however, in Study 2, statistically significant improvements were observed with UMEC 62.5+FP/SAL (Day 28) and UMEC 125+FP/SAL (Days 28 and 84) versus PBO+FP/SAL. The incidence of on-treatment adverse events across all treatment groups was 37-41% in Study 1 and 36-38% in Study 2. Overall, these data indicate that the combination of UMEC+FP/SAL can provide additional benefits over FP/SAL alone in patients with COPD

Estimating stellar ages and metallicities from parallaxes and broadband photometry - successes and shortcomings

A deep understanding of the Milky Way galaxy, its formation and evolution requires observations of huge numbers of stars. Stellar photometry, therefore, provides an economical method to obtain intrinsic stellar parameters. With the addition of distance information - deriving reliable ages from photometry is a possibility. We have developed a Bayesian method that generates 2D probability maps of a star's age and metallicity from photometry and parallax using isochrones. Our synthetic tests show that including a near-UV passband enables us to break the degeneracy between a star's age and metallicity for certain evolutionary stages. It is possible to find well-constrained ages and metallicities for turn-off and sub-giant stars with colours including a U band and a parallax with uncertainty less than ~20%. Metallicities alone are possible for the main sequence and giant branch. We find good agreement with the literature when we apply our method to the Gaia benchmark stars, particularly for turn-off and young stars. Further tests on the old open cluster NGC 188, however, reveal significant limitations in the stellar isochrones. The ages derived for the cluster stars vary with evolutionary stage, such that turn-off ages disagree with those on the sub-giant branch, and metallicities vary significantly throughout. Furthermore, the parameters vary appreciably depending on which colour combinations are used in the derivation. We identify the causes of these mismatches and show that improvements are needed in the modelling of giant branch stars and in the creation and calibration of synthetic near-UV photometry. Our results warn against applying isochrone fitting indiscriminately. In particular, the uncertainty on the stellar models should be quantitatively taken into account. Further efforts to improve the models will result in significant advancements in our ability to study the Galaxy.Comment: Accepted for publication in A&A. 22 pages, 19 figures (+ 6 pages of appendix). Abstract abridged for the arXi

High-Resolution spectroscopy of the low-mass X-ray binary EXO 0748-67

We present initial results from observations of the low-mass X-ray binary EXO 0748-67 with the Reflection Grating Spectrometer on board the XMM-Newton Observatory. The spectra exhibit discrete structure due to absorption and emission from ionized neon, oxygen, and nitrogen. We use the quantitative constraints imposed by the spectral features to develop an empirical model of the circumsource material. This consists of a thickened accretion disk with emission and absorption in the plasma orbiting high above the binary plane. This model presents challenges to current theories of accretion in X-ray binary systems.Comment: 5 pages, 4 figures, accepted by A&A letters, XMM special issu

Particulate 210Po and 210Pb from R/V Knorr KN199-04, KN204-01 in the Subtropical northern Atlantic Ocean from 2010-2011 (U.S. GEOTRACES NAT project)

Dataset: GT10-11 - Particulate Po PbParticulate 210Po and 210Pb from R/V Knorr KN199-04, KN204-01 in the Subtropical northern Atlantic Ocean from 2010-2011. For a complete list of measurements, refer to the full dataset description in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: https://www.bco-dmo.org/dataset/3917NSF Division of Ocean Sciences (NSF OCE) OCE-096135

Multiple haplotype-resolved genomes reveal population patterns of gene and protein diplotypes

To fully understand human biology and link genotype to phenotype, the phase of DNA variants must be known. Here we present a comprehensive analysis of haplotype-resolved genomes to assess the nature and variation of haplotypes and their pairs, diplotypes, in European population samples. We use a set of 14 haplotype-resolved genomes generated by fosmid clone-based sequencing, complemented and expanded by up to 372 statistically resolved genomes from the 1000 Genomes Project. We find immense diversity of both haploid and diploid gene forms, up to 4.1 and 3.9 million corresponding to 249 and 235 per gene on average. Less than 15% of autosomal genes have a predominant form. We describe a ‘common diplotypic proteome’, a set of 4,269 genes encoding two different proteins in over 30% of genomes. We show moreover an abundance of cis configurations of mutations in the 386 genomes with an average cis/trans ratio of 60:40, and distinguishable classes of cis- versus trans-abundant genes. This work identifies key features characterizing the diplotypic nature of human genomes and provides a conceptual and analytical framework, rich resources and novel hypotheses on the functional importance of diploidy

Unifying prospective and retrospective interval-time estimation: a fading-gaussian activation-based model of interval-timing

Hass and Hermann (2012) have shown that only variance-based processes will lead to the scalar growth of error that is characteristic of human time judgments. Secondly, a major meta-review of over one hundred studies (Block et al., 2010) reveals a striking interaction between the way in which temporal judgments are queried and cognitive load on participants’ judgments of interval duration. For retrospective time judgments, estimates under high cognitive load are longer than under low cognitive load. For prospective judgments, the reverse pattern holds, with increased cognitive load leading to shorter estimates. We describe GAMIT, a Gaussian spreading-activation model, in which the sampling rate of an activation trace is differentially affected by cognitive load. The model unifies prospective and retrospective time estimation, normally considered separately, by relating them to the same underlying process. The scalar property of time estimation arises naturally from the model dynamics and the model shows the appropriate interaction between mode of query and cognitive load