78 research outputs found

    AmiGO: online access to ontology and annotation data

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    AmiGO is a web application that allows users to query, browse and visualize ontologies and related gene product annotation (association) data. AmiGO can be used online at the Gene Ontology (GO) website to access the data provided by the GO Consortium1; it can also be downloaded and installed to browse local ontologies and annotations.2 AmiGO is free open source software developed and maintained by the GO Consortium

    Chandra Detection of a TypeII Quasar at z=3.288

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    We report on observations of a TypeII quasar at redshift z=3.288, identified as a hard X-ray source in a 185 ks observation with the Chandra X-ray Observatory and as a high-redshift photometric candidate from deep, multiband optical imaging. CXOJ084837.9+445352 (hereinafter CXO52) shows an unusually hard X-ray spectrum from which we infer an absorbing column density N(H) = (4.8+/-2.1)e23 / cm2 (90% confidence) and an implied unabsorbed 2-10 keV rest-frame luminosity of L(2-10) = 3.3e44 ergs/s, well within the quasar regime. Hubble Space Telescope imaging shows CXO52 to be elongated with slight morphological differences between the WFPC2 F814W and NICMOS F160W bands. Optical and near-infrared spectroscopy of CXO52 show high-ionization emission lines with velocity widths ~1000 km/s and flux ratios similar to a Seyfert2 galaxy or radio galaxy. The latter are the only class of high-redshift TypeII luminous AGN which have been extensively studied to date. Unlike radio galaxies, however, CXO52 is radio quiet, remaining undetected at radio wavelengths to fairly deep limits, f(4.8GHz) < 40 microJy. High-redshift TypeII quasars, expected from unification models of active galaxies and long-thought necessary to explain the X-ray background, are poorly constrained observationally with few such systems known. We discuss recent observations of similar TypeII quasars and detail search techniques for such systems: namely (1) X-ray selection, (2) radio selection, (3) multi-color imaging selection, and (4) narrow-band imaging selection. Such studies are likely to begin identifying luminous, high-redshift TypeII systems in large numbers. We discuss the prospects for these studies and their implications to our understanding of the X-ray background.Comment: 28 pages, 5 figures; to appear in The Astrophysical Journa

    Megafauna extinction, tree species range reduction, and carbon storage in Amazonian forests

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    During the Late Pleistocene and early Holocene 59 species of South American megafauna went extinct. Their extinction potentially triggered population declines of large-seeded tree species dispersed by the large-bodied frugivores with which they co-evolved, a theory first proposed by Janzen and Martin (1982). We tested this hypothesis using species range maps for 257 South American tree species, comparing 63 species thought to be primarily distributed by megafauna with 194 distributed by other animals. We found a highly significant (p 95% following disperser extinction. A numerical gap dynamic simulations suggests that over a 10 000 yr period following the disperser extinctions, the average convex hull range size of large-seeded tree species decreased by ∼ 31%, while the estimated decrease in population size was ∼ 54%, indicating a likely greater decrease in species population size than indicated by the empirical range patterns. Finally, we found a positive correlation between seed size and wood density of animal-dispersed tree species implying that the Late Pleistocene and early Holocene megafaunal extinctions reduced carbon content in the Amazon by ∼ 1.5 ± 0.7%. In conclusion, we 1) provide some empirical evidence that megafauna distributed fruit species have a smaller mean range size than wind, water or other animal-dispersed species, 2) demonstrate mathematically that such range reductions are expected from megafauna extinctions ca 12 000 yr ago, and 3) illustrate that these extinctions may have reduced the Amazon's carbon storage capacity

    Lifespan extension and the doctrine of double effect

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    Recent developments in biogerontology—the study of the biology of ageing—suggest that it may eventually be possible to intervene in the human ageing process. This, in turn, offers the prospect of significantly postponing the onset of age-related diseases. The biogerontological project, however, has met with strong resistance, especially by deontologists. They consider the act of intervening in the ageing process impermissible on the grounds that it would (most probably) bring about an extended maximum lifespan—a state of affairs that they deem intrinsically bad. In a bid to convince their deontological opponents of the permissibility of this act, proponents of biogerontology invoke an argument which is grounded in the doctrine of double effect. Surprisingly, their argument, which we refer to as the ‘double effect argument’, has gone unnoticed. This article exposes and critically evaluates this ‘double effect argument’. To this end, we first review a series of excerpts from the ethical debate on biogerontology in order to substantiate the presence of double effect reasoning. Next, we attempt to determine the role that the ‘double effect argument’ is meant to fulfil within this debate. Finally, we assess whether the act of intervening in ageing actually can be justified using double effect reasoning

    The bien r package: A tool to access the Botanical Information and Ecology Network (BIEN) database

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    There is an urgent need for largeâ scale botanical data to improve our understanding of community assembly, coexistence, biogeography, evolution, and many other fundamental biological processes. Understanding these processes is critical for predicting and handling humanâ biodiversity interactions and global change dynamics such as food and energy security, ecosystem services, climate change, and species invasions.The Botanical Information and Ecology Network (BIEN) database comprises an unprecedented wealth of cleaned and standardised botanical data, containing roughly 81 million occurrence records from c. 375,000 species, c. 915,000 trait observations across 28 traits from c. 93,000 species, and coâ occurrence records from 110,000 ecological plots globally, as well as 100,000 range maps and 100 replicated phylogenies (each containing 81,274 species) for New World species. Here, we describe an r package that provides easy access to these data.The bien r package allows users to access the multiple types of data in the BIEN database. Functions in this package query the BIEN database by turning user inputs into optimised PostgreSQL functions. Function names follow a convention designed to make it easy to understand what each function does. We have also developed a protocol for providing customised citations and herbarium acknowledgements for data downloaded through the bien r package.The development of the BIEN database represents a significant achievement in biological data integration, cleaning and standardization. Likewise, the bien r package represents an important tool for open science that makes the BIEN database freely and easily accessible to everyone.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/142458/1/mee312861_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/142458/2/mee312861.pd

    Evidence of multidecadal salinity variability in the eastern tropical North Atlantic

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    Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Paleoceanography 21 (2006): PA3010, doi:10.1029/2005PA001257.Ocean circulation and global climate are strongly influenced by seawater density, which is itself controlled by salinity and temperature. Although adequate instrumental sea-surface temperature (SST) records exist for most of the surface oceans over the past 100-150 years, records of salinity really only exist for the last 40-50 years. Here we show that longer proxy records from corals (Siderastrea radians) in the eastern tropical North Atlantic are dominated by multi-decadal variations in salinity which are correlated with the relationship between SST and the North Atlantic Oscillation (NAO) over the course of the 20th century. The data reveal an increase in eastern tropical North Atlantic salinity of +0.5 psu between about 1950-1990. Rather than a monotonic secular increase, as indicated by some instrumental records, the pre-instrumental coral proxy records presented here suggest that salinity in the tropical North Atlantic is periodic on a decadal to multi-decadal scale

    Crop Updates 2000 - Weeds

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    This session covers thirty six papers from different authors: INTRODUCTION, Vanessa Stewart Agriculture Western Australia INTEGRATED WEED MANAGEMENT Effect of seeding density, row spacing and Trifluralin on the competitive ability of Annual Ryegrass in a minimum tillage system, David Minkey, Abul Hashem, Glen Riethmuller and Martin Harries, Agriculture Western Australia High wheat seeding rates coupled with narrow row spacing increases yield and suppresses grass, Peter Newman1 and Cameron Weeks2,1Agronomist, Elders Limited 2Mingenew/Irwin Group Resistant ryegrass management in a wheat – lupin rotation, Abul Hashem, Harmohinder S. Dhammu, Aik Cheam, David Bowran and Terry Piper, Agriculture Western Australia Integrated weed management – Will it work with my rotation? Alexandra Wallace, Agriculture Western Australia Long term herbicide resistance trial – Mingenew, Peter Newman Elders, Cameron Weeks Mingenew-Irwin Group Is two years enough? Bill Roy, Agricultural Consulting and Research Services The fate of ryegrass seed when sheep graze chaff cart heaps, Keith L. Devenish1 and Lisa J. Leaver2 1 Agriculture Western Australia, 2Curtin University of Technology, Muresk Institute of Agriculture Can blanket wiping and crop topping prevent seed set of resistant wild radish and mustard? StAbul Hashem, Harmohinder Dhammu, Vanessa Stewart, Brad Rayner and Mike Collins, Agriculture Western Australia The value of green manuring in the integrated management of ryegrass, Marta Monjardino1,2, David Pannell2, Stephen Powles1 ,1Western Australia Herbicide Resistance Initiative, 2Agricultural and Resource Economics, University of Western Australia Some ways of increasing wheat competitiveness against ryegrass,, Mike Collins Centre for Cropping Systems, Agriculture Western Australia WEED BIOLOGY Understanding and driving weed seed banks to very low levels, Sally Peltzer, Agriculture Western Australi HERBICIDE RESISTANCE Cross resistance of chlorsulfuron-resistant wild radish to imidazolinones, Abul Hashem, Harmohinder Dhammu and David Bowran, Agriculture Western Australia Investigation of suspected triazine resistant ryegrass populations for cross-resistance and multiple resistance to herbicides, Michael Walsh, Charles Boyle and Stephen Powles, Western Australian Herbicide Resistance Initiative, University of Western Australia Genetics and fitness of glyphosate resistant ryegrass, S. Powles1, P. Neve1, D. Lorraine-Colwill2, C. Preston2 ,1WAHRI, University of Western Australia 2 CRC Weed Management Systems, University of Adelaide Managing herbicide resistance – the effect of local extinction of resistance genes, Art Diggle1, Paul B. Neve2, Stephen B. Powles2 ,1Agriculture Western Australia, 2WAHRI, Faculty of Agriculture, University of Western Australia The double knock - the best strategy for conserving glyphosate susceptibility? Paul B. Neve1, Art Diggle2, Stephen B. Powles1,1WAHRI, Faculty of Agriculture, University of Western Australia, 2Agriculture Western Australia Wild radish had evolved resistance to triazines, Abul Hashem, Harmohinder S. Dhammu, David Bowran and Aik Cheam, Agriculture Western Australia Ryegrass resistance in Western Australia – where and how much? Rick Llewellyn and Stephen Powles, Western Australian Herbicide Resistance Initiative, Faculty of Agriculture, University of Western Australia Wild radish herbicide resistance survey, Michael Walsh, Ryan Duane and Stephen Powles, Western Australian Herbicide Resistance Initiative, University of Western Australia Knockdown resistance in the Western Australian wheatbelt – a proposed survey, Paul B. Neve1, Abul Hashem2, Stephen B. Powles1,1Western Australian Herbicide Resistance Initiative, University of Western Australia, 2Agriculture Western Australia Diflufenican resistant wild radish, Aik Cheam, Siew Lee, David Bowran, David Nicholson and Abul Hashem, Agriculture Western Australi Multiple resistance to triazines and diflufenican further complicates wild radish control, Aik Cheam, Siew Lee, David Bowran, David Nicholson and Abul Hashem, Agriculture Western Australia HERBICIDE TOLERANCE 25. Herbicide tolerance of lupins, Terry Piper, Weed Science Group, Agriculture Western Australia 26. Tanjil lupins will tolerate metribuzin under the right conditions, Peter Newman, Agronomist Elders Limited and Cameron Weeks, Mingenew/Irwin Group 27. Herbicide damage does not mean lower yield in Lupins, Peter Carlton, Trials Coordinator, Elders Limited 28. Herbicide tolerance of new pea varieties, Dr Terry Piper, Agriculture Western Australia 29. Herbicide tolerance of (waterlogged) wheat, Dr Terry Piper, Agriculture Western Australia 30. Wheat tolerance trials – Mingenew 1999, Peter Newman1, Cameron Weeks2 and Stewart Smith3,1Elders, Mingenew, 2Mingenew-Irwin Group,3Agriculture Western Australia ISSUES OF TRIFLURALIN USE 31. Trifluralin works better on ryegrass when no-tilling into thick wheat stubbles as granules, or mixed with limesand, Bill Crabtree, WANTFA Scientific Officer 32. Increasing trifluralin rate did not compensate for delaying incorporation, Bill Crabtree, WANTFA Scientific Officer 33. Poor emergence survey, 1999, Terry Piper, Weed Science Group, Agriculture Western Australia HERBICIDES – ISSUES AND OPTIONS 34. AFFINITY 400DF – A new herbicide with a new mode of action (Group G) for Broadleaf Weed Control in Cereals, Gordon Cumming, Technical Officer, Crop Care Australasia 35 Herbicide screening for Marshmallow, David Minkey1 and David Cameron2,1Agriculture Western Australia, 2Elders Ltd, Merredin 36. The control of Capeweed in Clearfield Production System for Canola, Mike Jackson and Scott Paton, Cyanamid Agriculture Pty Ltd 37.Effect of herbicides Tordonä 75D and Lontrelä,used for eradication of Skeleton Weed, on production of Lupins I the following seasons, John R. Peirce and Brad J. Rayner, Agriculture Western Australia INDUSTRY PROTECTION 38. Graingaurd – Opportunities for agribusiness to help protect the West Australian grains industry, Greg Shea, Executive Officer, GrainGuard Agriculture Western Australi

    Habitat area and climate stability determine geographical variation in plant species range sizes

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    Despite being a fundamental aspect of biodiversity, little is known about what controls species range sizes. This is especially the case for hyperdiverse organisms such as plants. We use the largest botanical data set assembled to date to quantify geographical variation in range size for ∼ 85 000 plant species across the New World. We assess prominent hypothesised range-size controls, finding that plant range sizes are codetermined by habitat area and long- and short-term climate stability. Strong short- and long-term climate instability in large parts of North America, including past glaciations, are associated with broad-ranged species. In contrast, small habitat areas and a stable climate characterise areas with high concentrations of small-ranged species in the Andes, Central America and the Brazilian Atlantic Rainforest region. The joint roles of area and climate stability strengthen concerns over the potential effects of future climate change and habitat loss on biodiversity

    Speciation and fate of trace metals in estuarine sediments under reduced and oxidized conditions, Seaplane Lagoon, Alameda Naval Air Station (USA)

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    We have identified important chemical reactions that control the fate of metal-contaminated estuarine sediments if they are left undisturbed (in situ) or if they are dredged. We combined information on the molecular bonding of metals in solids from X-ray absorption spectroscopy (XAS) with thermodynamic and kinetic driving forces obtained from dissolved metal concentrations to deduce the dominant reactions under reduced and oxidized conditions. We evaluated the in situ geochemistry of metals (cadmium, chromium, iron, lead, manganese and zinc) as a function of sediment depth (to 100 cm) from a 60 year record of contamination at the Alameda Naval Air Station, California. Results from XAS and thermodynamic modeling of porewaters show that cadmium and most of the zinc form stable sulfide phases, and that lead and chromium are associated with stable carbonate, phosphate, phyllosilicate, or oxide minerals. Therefore, there is minimal risk associated with the release of these trace metals from the deeper sediments contaminated prior to the Clean Water Act (1975) as long as reducing conditions are maintained. Increased concentrations of dissolved metals with depth were indicative of the formation of metal HS(- )complexes. The sediments also contain zinc, chromium, and manganese associated with detrital iron-rich phyllosilicates and/or oxides. These phases are recalcitrant at near-neutral pH and do not undergo reductive dissolution within the 60 year depositional history of sediments at this site. The fate of these metals during dredging was evaluated by comparing in situ geochemistry with that of sediments oxidized by seawater in laboratory experiments. Cadmium and zinc pose the greatest hazard from dredging because their sulfides were highly reactive in seawater. However, their dissolved concentrations under oxic conditions were limited eventually by sorption to or co-precipitation with an iron (oxy)hydroxide. About 50% of the reacted CdS and 80% of the reacted ZnS were bonded to an oxide-substrate at the end of the 90-day oxidation experiment. Lead and chromium pose a minimal hazard from dredging because they are bonded to relatively insoluble carbonate, phosphate, phyllosilicate, or oxide minerals that are stable in seawater. These results point out the specific chemical behavior of individual metals in estuarine sediments, and the need for direct confirmation of metal speciation in order to constrain predictive models that realistically assess the fate of metals in urban harbors and coastal sediments
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