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Full-Text Articles in Social and Behavioral Sciences
Stratigraphic Distribution And Suggested Evolution Of Dendroid Graptolites From The Silurian Of Eastern Australia, Barrie Rickards, Anthony Wright
Stratigraphic Distribution And Suggested Evolution Of Dendroid Graptolites From The Silurian Of Eastern Australia, Barrie Rickards, Anthony Wright
Anthony Wright
Five evolutionary lineages are proposed for Silurian species of the benthic dendroid graptolite genus Dictyonema, based largely on the exceptional eastern Australian records of the genus, comprising at least 25 species. These are: A, the delicatulum lineage with bifurcating ventral autothecal apertural spines; B, the paululum lineage with single ventral apertural spines or processes; C, the elegans lineage with isolated thecal apertures ± processes; D, the sherrardae lineage with dorsal apertural processes; and E, the venustum lineage with simple autothecal apertures. Brief comments are also made on other dendroid genera occurring in Australian strata, namely: Acanthograptus, Koremagraptus, Callograptus, Dendrograptus, Stelechocladia, …
Late Quaternary Aeolian And Fluvial Interactions On The Cooper Creek Fan And The Association Between Linear And Source-Bordering Dunes, Strzelecki Desert, Australia, Timothy Cohen, Gerald Nanson, Joshua Larsen, B. Jones, David Price, Maria Coleman, Tim Pietsch
Late Quaternary Aeolian And Fluvial Interactions On The Cooper Creek Fan And The Association Between Linear And Source-Bordering Dunes, Strzelecki Desert, Australia, Timothy Cohen, Gerald Nanson, Joshua Larsen, B. Jones, David Price, Maria Coleman, Tim Pietsch
B. G. Jones
The Innamincka Dome and associated low-gradient fan in the Strzelecki Desert is the product of Cenozoic crustal warping that has aided formation of an extensive array of palaeochannels, source-bordering transverse dunes and superimposed linear dunes. These dunes have impeded the course of Cooper Creek and provided a repository of evidence for Quaternary climate change as well as the interactive processes between transverse and linear dune formation. At Turra, Gidgealpa and sites nearby are extensive fluvial and aeolian sand bodies that date from marine isotope stages (MIS) 8-3 and the Last Glacial Maximum (LGM) and are now surrounded or buried by …
Communication: New Insight Into The Barrier Governing Co2 Formation From Oh + Co, Christopher Johnson, Berwyck Poad, Ben Shen, Robert Continetti
Communication: New Insight Into The Barrier Governing Co2 Formation From Oh + Co, Christopher Johnson, Berwyck Poad, Ben Shen, Robert Continetti
Berwyck L. J. Poad
Despite its relative simplicity, the role of tunneling in the reaction OH + CO → H + CO(2) has eluded the quantitative predictive powers of theoretical reaction dynamics. In this study a one-dimensional effective barrier to the formation of H + CO(2) from the HOCO intermediate is directly extracted from dissociative photodetachment experiments on HOCO and DOCO. Comparison of this barrier to a computed minimum-energy barrier shows that tunneling deviates significantly from the calculated minimum-energy pathway, predicting product internal energy distributions that match those found in the experiment and tunneling lifetimes short enough to contribute significantly to the overall reaction. …
Dirt, Dates And Dna:Osl And Radiocarbon Chronologies Of Perenially Frozen Sediments In Siberia, And Their Implications For Sedimentary Ancient Dna Studies, Lee Arnold, Richard Roberts, Ross Macphee, James Haile, Fiona Brock, Per Moller, Duane Froese, Alexei Tikhonov, Allan Chivas, M. Thomas Gilbert, Eske Willerslev
Dirt, Dates And Dna:Osl And Radiocarbon Chronologies Of Perenially Frozen Sediments In Siberia, And Their Implications For Sedimentary Ancient Dna Studies, Lee Arnold, Richard Roberts, Ross Macphee, James Haile, Fiona Brock, Per Moller, Duane Froese, Alexei Tikhonov, Allan Chivas, M. Thomas Gilbert, Eske Willerslev
Richard G Roberts
The sedimentary ancient DNA (sedaDNA) technique offers a potentially invaluable means of investigating species evolution and extinction dynamics in high-latitude environments. An implicit assumption of the sedaDNA approach is that the extracted DNA is autochthonous with the host deposit and that it has not been physically transported from older source deposits or reworked within the sedimentary profile by postdepositional mixing. In this paper we investigate whether these fundamental conditions are upheld at seven perennially frozen wetland sites across the Taimyr Peninsula and coastal lowlands of north-central Siberia. Optically stimulated luminescence (OSL) and radiocarbon (14C) dating are used to constrain the …
Approaches To Development Of A User-Friendly Community Based Arsenic/Iron Removal Unit In Bangladesh, Khondoker Mahabub Hassan, Farooque Ahmed, Faisal Hai, Saleh Faraj Magram
Approaches To Development Of A User-Friendly Community Based Arsenic/Iron Removal Unit In Bangladesh, Khondoker Mahabub Hassan, Farooque Ahmed, Faisal Hai, Saleh Faraj Magram
Faisal I Hai
The present stydy focuses on the strategies to modify the design of a community based Arsenic - Iron Removal Unit (AIRU) based on the field performance of the AIRU and the feedback from the users. The ultimate aim was to offer a user-friendly and sustainable system. Appropriate modifications in the design of the developed unit reduced the propensities of water head-loss and media clogging, thereby yielding sustained flow rate. Introduction of a simple cleaning procerdure (98% flow-recovery with three successive backwashing sequences) successfully reduced the frequency of requirement of labor-intensive replacement of the whole filter media. Raw water with arsenic …