Iron in Surface and Subsurface Waters, Grizzly Bar, Southeastern Alaska

Completion Report for Project A-019-ALAS to the Office of Water Resources Research, Department of the Interior, August 1972Atomic absorption spectrophotometric measurements for total iron were made on 69 samples of water from 8 different environments in an outwash fan built by meltwater streams from the retreating Norris Glacier on granodiorite bedrock. Norris Glacier ice contained no iron (3 samples), a subglacial stream contained 5.5 ppm Fe (1 sample), and a meltwater lake fronting Norris Glacier contained 0.7 ppm Fe (3 samples). Iron content of ground water from outwash ranged between 0.0 and 17.0 ppm (6 samples); surface streams fed by emergent ground water on the fan periphery contained 0.0 to 0.2 ppm Fe (13 samples). Taku Inlet waters contained 6.4 ppm Fe (3 samples). Subsurface water from an intertidal mud flat contained between 0.0 and 27.0, X 5.9, ppm Fe (31 samples). Surface and subsurface water from a bog and associated stream contained 1 ppm Fe (12 samples). Little exchangeable Fe was found. In situ measurements in water for Eh showed large positive values (+0.30 to +0.50 volts) and pH was slightly alkaline. The single most important source of iron was vermiculitized biotite. Iron was transported in water in the particulate state, except in outwash ground water where particulate Fe+3 was reduced to dissolved Fe+2. Iron deposits of Fe(OH)3 were found near the top of the outwash water table.The work upon which this report is based was supported in part by the funds (Proj. A·019-ALAS) provided by the United States Department of the Interior, Office of Water Resources Research, as authorized under the Water Resources Act of 1964, as amended

Exploring the Cosmic Evolution of Habitability with Galaxy Merger Trees

We combine inferred galaxy properties from a semi-analytic galaxy evolution model incorporating dark matter halo merger trees with new estimates of supernova and gamma ray burst rates as a function of metallicity from stellar population synthesis models incorporating binary interactions. We use these to explore the stellar mass fraction of galaxies irradiated by energetic astrophysical transients and its evolution over cosmic time, and thus the fraction which is potentially habitable by life like our own. We find that 18 per cent of the stellar mass in the Universe is likely to have been irradiated within the last 260 Myr, with GRBs dominating that fraction. We do not see a strong dependence of irradiated stellar mass fraction on stellar mass or richness of the galaxy environment. We consider a representative merger tree as a Local Group analogue, and find that there are galaxies at all masses which have retained a high habitable fraction (>40 per cent) over the last 6 Gyr, but also that there are galaxies at all masses where the merger history and associated star formation have rendered galaxies effectively uninhabitable. This illustrates the need to consider detailed merger trees when evaluating the cosmic evolution of habitability.Comment: 11 page, 10 figures. MNRAS accepted 13th Dec 2017. Updated to match accepted version, with additional discussion of metallicity effect

Antarctic Meteorites: A Statistical Look at a Uniquely Valuable Resource

As of the end of the 2018-19 field season, the U.S. Antarctic meteorite program has surpassed 23,000 meteorites collected. The U.S. collection is valuable in that it is classified in its entirety. The systematic methods employed to collect the meteorites have provided meteorites of more than 40 types, many of which are the first of their type ever recognized. One of the early drivers for consistent and methodical characterization of the entire U.S. Antarctic collection was to allow statistical comparisons. Early statistical assessments of the U.S. Antarctic collection examined mass distributions and the relative frequency of meteorite types as well as comparisons to a defined set of modern falls. Using these statistics argued that the flux of H chondrites changed over time used model size distributions to deconstruct the contribution of wind movement, meteorite supply and search losses to the Antarctic collection. Mass-based statistics and size distribution comparisons were examined by investigated various aspects of the statistics, including comparison with modern falls/Saharan finds. Also discuss geospatial statistics provides a comprehensive overview of the statistics of the Antarctic collections for the first 35 seasons of U.S. collection by ANSMET. Here we build upon that assessment and that from

Remote sensing study of land use and sedimentation in the Ross Barnett Reservoir, Jackson, Mississippi area

This multi-year study is aimed at focusing on the recognition of sediment and other affluents in a selected area of the Ross Barnett Reservoir. The principle objectives are the determination of land use types, effect of land use on erosion, and the correlation of sediment with land use in the area. The I2S multi-band imagery was employed in conjunction with ground truth data for both water and land use studies. The selected test site contains approximately forty square miles including forest, open land, and water in addition to residential and recreational areas

Pleistocene, Holocene and Recent Bird Gastroliths from Interior Alaska

Describes and discusses the origin of polished and rounded grains of quartz, secondary quartz, and chert from (probably) Holocene loess of Easter Egg Hill near Livengood townsite, peat on the Nenana Road, and redeposited Wisconsin loess from the Eva Creek Mine and Ready Bullion Creek Mine at 64 51 N, 148 02 W. The association of these grains with dull, angular grains of the same materials rules out soil or solifluction abrasion in place. Gizzard-bearing birds such as ptarmigan and grouse in Alaska produce glossy polish on their gizzard stones (gastroliths) comparable to that of the Pleistocene and Holocene gastroliths; the polish and roundness of the stones in living birds are more pronounced in late winter. Because the modal size classes of ancient and Recent polished gastroliths do not coincide, some of the ancient gastroliths are believed to have been produced by birds not now living in interior Alaska.Gastrolithes d'oiseaux pléistocènes, holocènes et récents de l'Alaska intérieur. On trouve dans le loess et la tourbe de l'Alaska intérieur des grains polis et arrondis de quartz, de quartz secondaire et de chert. Le diamètre intermédiaire de ces grains se situe entre 35 et 0.07 mm, les plus abondants mesurant 0.07 mm, de 2 à 4 mm et peut-être, de 10 à 20 mm. Le poli de ces grains est le produit de l'abrasion dans des gésiers d'oiseaux. Les oiseaux à gésier qui vivent aujourd'hui dans l'Alaska intérieur produisent sur leurs gastrolithes un fini poli comparable à celui des gastrolithes des dépôts holocènes et pléistocènes. Sur les gastrolithes d'oiseaux récents, le poli et l'arrondi varient directement, atteignant un maximum pour les oiseaux vivants à la fin de l'hiver. On peut croire que certaines gastrolithes polies de l'Holocène et du Pléistocène ont été produites par des oiseaux qui ne vivent plus aujourd'hui dans l'Alaska intérieur, car les classes dimensionnelles de ces gastrolithes anciennes ne coïncident plus avec celles des gastrolithes des oiseaux d'aujourd'hui

PD-0136: Hypoxia biomarkers for prognostic evaluation and the prediction of outcome following prostate radiotherapy

Hom Santolaia, Cinto; Casamor Maldonado, Carlo

British research in accounting and finance (2001–2007): the 2008 research assessment exercise

No abstract available

Long distance (>20 km) downstream detection of endangered stream frogs suggests an important role for eDNA in surveying for remnant amphibian populations

Background Globally, amphibian species have suffered drastic population declines over the past 40 years. Hundreds of species are now listed as Critically Endangered, with many of these considered “possibly extinct”. Most of these species are stream-dwelling frogs inhabiting remote, montane areas, where remnant populations are hard to find using traditional surveys. Environmental DNA (eDNA) could revolutionize surveys for ‘missing’ and endangered amphibian populations by screening water samples from downstream sections to assess presence in the upstream catchments. However, the utility of this survey technique is dependent on quantifying downstream detection probability and distances. Methods Here we tested downstream detection distances in two endangered stream frogs (Litoria lorica and L. nannotis) that co-occur in a remote stream catchment in north-east Australia, and for which we know precise downstream distributional limits from traditional surveys. Importantly, the two last populations of L. lorica persist in this catchment: one small (~1,000 frogs) and one very small (~100 frogs). We conducted eDNA screening at a series of sites kilometers downstream from the populations using precipitation from two fixed water volumes (15 and 100 mL) and via water filtering (mean 1,480 L). Results We detected L. nannotis and the small L. lorica population (~1,000 frogs) at most sampling sites, including 22.8 km downstream. The filtration method was highly effective for far-downstream detection, as was precipitation from 100 mL water samples, which also resulted in consistent detections at the far-downstream sites (including to 22.8 km). In contrast, we had limited downstream detection success for the very small L. lorica population (~100 frogs). Discussion The ecological aspects of our study system, coupled with thorough traditional surveys, enabled us to measure downstream eDNA detection distances with accuracy. We demonstrate that eDNA from a small population of approximately 1,000 frogs can be detected as far as 22.8 km downstream from the population. Water filtration is considered best for eDNA detection of rare aquatic species—indeed it was effective in this study—but we also achieved far-downstream detections when precipitating eDNA from 100 mL water samples. Collecting small water volumes for subsequent precipitation in the lab is more practical than filtration when surveying remote areas. Our downstream detection distances (>20 km) suggest eDNA is a valuable tool for detecting rare stream amphibians. We provide recommendations on optimal survey methods

Composition of a chemical signalling trait varies with phylogeny and precipitation across an Australian lizard radiation

The environment presents challenges to the transmission and detection of animal signalling systems, resulting in selective pressures that can drive signal divergence amongst populations in disparate environments. For chemical signals, climate is a potentially important selective force because factors such as temperature and moisture influence the persistence and detection of chemicals. We investigated an Australian lizard radiation (Heteronotia) to explore relationships between a sexually dimorphic chemical signalling trait (epidermal pore secretions) and two key climate variables: temperature and precipitation. We reconstructed the phylogeny of Heteronotia with exon capture phylogenomics, estimated phylogenetic signal in amongst-lineage chemical variation and assessed how chemical composition relates to temperature and precipitation using multivariate phylogenetic regressions. High estimates of phylogenetic signal indicate that the composition of epidermal pore secretions varies amongst lineages in a manner consistent with Brownian motion, although there are deviations to this, with stark divergences coinciding with two phylogenetic splits. Accounting for phylogenetic non-independence, we found that amongst-lineage chemical variation is associated with geographic variation in precipitation but not temperature. This contrasts somewhat with previous lizard studies, which have generally found an association between temperature and chemical composition. Our results suggest that geographic variation in precipitation can affect the evolution of chemical signalling traits, possibly influencing patterns of divergence amongst lineages and species

Whole body and splanchnic amino acid metabolism in sheep during an acute endotoxin challenge

Acknowledgements The expertise of A. Graham Calder and Susan Anderson for the various stable isotope analyses is gratefully recognised. Ngaire Dennison is also thanked for her surgical expertise with the trans-splanchnic tissue catheter preparations. This study was supported by funds provided to the Rowett Institute of Nutrition and Health, University of Aberdeen and Biomathematics and Statistics Scotland by the Rural and Environment Science and Analytical Services Division of the Scottish Government. S. O. H. was a recipient of a FoRST (NZ) award to study abroad.Peer reviewedPostprin