13 research outputs found
Overactivation of fear systems to neutral faces in schizophrenia
Background The amygdala plays a central role in detecting and responding to fear-related stimuli. A number of recent studies have reported decreased amygdala activation in schizophrenia to emotional stimuli (such as fearful faces) compared with matched neutral stimuli (such as neutral faces). We investigated whether the apparent decrease in amygdala activation in schizophrenia could actually derive from increased amygdala activation to the neutral comparator stimuli. Methods Nineteen patients with schizophrenia and 24 matched control participants viewed pictures of faces with either fearful or neutral facial expressions, and a baseline condition, during functional magnetic resonance imaging scanning. Results Patients with schizophrenia showed a relative decrease in amygdala activation to fearful faces compared with neutral faces. However, this difference resulted from an increase in amygdala activation to the neutral faces in patients with schizophrenia, not from a decreased response to the fearful faces. Conclusions Patients with schizophrenia show an increased response of the amygdala to neutral faces. This is sufficient to explain their apparent deficit in amygdala activation to fearful faces compared with neutral faces. The inappropriate activation of neural systems involved in fear to otherwise neutral stimuli may contribute to the development of psychotic symptoms in schizophrenia
Environmental significance of mid- to late Holocene sapropels in Old Man Lake, Coorong coastal plain, South Australia: an isotopic, biomarker and palaeoecological perspective
The Holocene successions of numerous shallow lakes located along the Coorong coastal plain in South Australia attest to the impact of rising sea level and changing climate on their depositional environment. Old Man Lake is one of the smallest perennial alkaline lakes in the region. Its succession comprises a basal lagoonal sand rich in humic organic matter (OM) overlain by a 3.7 m thick upward shoaling lacustrine mudstone. The latter features three discrete sapropel units deposited between 3270 and 4910 cal yr BP, a time of increasing aridity throughout southeastern Australia. A core taken from the lake’s eastern margin yielded sedimentological, mineralogical, geochronological and micropaleontological data. Coring at five other sites across the lake provided sections of the humic and sapropelic facies (n = 20) for total organic carbon and Rock–Eval analysis; isotopic characterization of their micritic carbonate (δ13Ccarb, δ18Ocarb) and co-existing OM (δ13Corg); and GC–MS and GC–irMS analysis of their free aliphatic hydrocarbons. For each ‘sapropel event’ high productivity of diatoms and green algae was the principal driver of the accumulation and preservation of OM in such high concentrations. The precursor algal blooms were likely triggered by the influx of fresh water following winter rainfall. The combination of kerogen hydrogen index and δ13Ccarb–δ13Corg, previously employed to track secular changes in algal productivity and organic preservation, proved useful in identifying synchronous geographic differences in these processes across the lake. Highly branched isoprenoids (HBI: C25:1 ≫ C20:0) are prominent components of the aliphatic hydrocarbons in the sapropels, confirming the significant contribution of diatoms to their OM. The C isotopic signatures of the principal C25:1 HBI isomer and the co-occurring C23–C31 odd carbon numbered n-alkanes further document the non-uniformity of biomass preservation within and between the three sapropel units. The evidence from this study suggests that seasonal algal blooms and meromixis, although not necessarily an anoxic hypoliminion, were required for sapropel formation in the Holocene lakes of the Coorong region. Higher resolution sampling, dating and comparative analysis (microfossil, biomarker and isotopic) of these sapropels is required to clarify their potential significance as palaeoclimate proxies
Remotely constraining the temporal evolution of offshore oil systems
An understanding of the temporal evolution of a petroleum system is fundamental to interpreting where hydrocarbons may be trapped in the subsurface. However, traditional exploration methods provide few absolute constraints on the timing of petroleum generation. Here we show that 187Re/187Os geochronology may be applied to natural crude oil seepage to determine when petroleum generation occurred in offshore sedimentary basins. Using asphaltites collected from the South Australian coastline, our determined Re-Os age (68 ± 15 million years ago) is consistent with their derivation from a Late Cretaceous source rock in the nearby Bight Basin, an interpretation similarly favoured by source-specific biomarker constraints. Furthermore, the calculated initial 187Os/188Os composition of the asphaltites, a value inherited from the source rock at the time of oil generation, suggests that the source rock represents the later stage of Oceanic Anoxic Event 2. Our results demonstrate a new approach to identifying the origin of crude oils encountered in coastal environments by providing direct constraints on the timing of petroleum generation and potential source rock intervals in poorly characterised offshore sedimentary basins prior to exploratory drilling
The glacial succession of Sturtian age in South Australia: the Yudnamutana Subgroup
The record of two Neoproterozoic glaciations in South Australia has been known for about a century. The earlier glaciation, of Sturtian age, is represented by the Yudnamutana Subgroup and is characterized by widespread diamictites with both intrabasinal and extrabasinal clasts, some locally faceted and striated. Associated facies include shallow-water sandstone, bedded and laminated siltstone with lonestones and dropstones, and sedimentary ironstones (mainly ferruginous siltstone and diamictite). Proximal settings adjacent to the Curnamona Province display massive basement-derived conglomerate and gigantic basement megaclasts (up to hundreds of metres across). Sturtian glaciogenic sediments of the Yudnamutana Subgroup unconformably overlie a variety of older rock units, including crystalline basement near basin margins and uppermost Burra Group sediments in the depocentre, and were deposited both in shallow marine shelf environments and in tectonically active rift basins encircling the Curnamona Province, with corresponding increases in total thickness from 100-300 m to more than 5 km. Recent U-Pb zircon SHRIMP dating of a thin volcaniclastic layer indicates that the waning stages of the Sturtian glaciation occurred at c. 660 Ma. Unlike the deposits of the younger Elatina glaciation, the Yudnamutana Subgroup has so far not yielded reliable palaeomagnetic data
Chapter 70 The Elatina glaciation (late Cryogenian), South Australia
<p>Deposits of the late Cryogenian Elatina glaciation constitute the Yerelina Subgroup in the Adelaide Geosyncline region, South
Australia. They have a maximum thickness of <em>c</em>. 1500 m, cover 200 000 km<sup>2</sup>, and include the following facies: basal boulder diamictite with penetrative glaciotectonites affecting preglacial beds;
widespread massive and stratified diamictites containing faceted and striated clasts, some derived from nearby emergent diapiric
islands and others of extrabasinal provenance; laminated siltstone and mudstone with dropstones; tidalites and widespread
glaciofluvial, deltaic to marine-shelf sandstones; a regolith of frost-shattered quartzite breccia up to 20 m thick that contains
primary sand wedges 3+ m deep and other large-scale periglacial forms; and an aeolian sand sheet covering 25 000 km<sup>2</sup> and containing primary sand wedges near its base. These deposits mark a spectrum of settings ranging from permafrost regolith
and periglacial aeolian on the cratonic platform (Stuart Shelf) in the present west, through glaciofluvial, marginal-marine
and inner marine-shelf in the central parts of the Adelaide Geosyncline, to outer marine-shelf in sub-basins in the present
SE and north.
</p> <p>The Elatina glaciation has not been dated directly, and only maximum and minimum age limits of <em>c</em>. 640 and 580 Ma, respectively, are indicated. Palaeomagnetic data for red beds from the Elatina Formation (Fm.) and associated
strata indicate deposition of the Yerelina Subgroup within 10° of the palaeoequator. The Yerelina Subgroup is unconformably
to disconformably overlain by the dolomitic Nuccaleena Fm., which in most places is the lowest unit of the Wilpena Group and
marks Early Ediacaran marine transgression.
</p
A second type of highly asphaltic crude oil seepage stranded on the South Australian coastline
Pyrolysis of a naturally dried Botryococcus braunii residue
The extant chlorophyte microalga Botryococcus braunii is a potential source of biofuel. In any future biofuel plant, it may be dried and stockpiled after harvesting and then pyrolyzed to generate oil. To investigate the formation of bio-oil from B. braunii, its naturally occurring residue known as coorongite was pyrolyzed non-isothermally and isothermally under about 1 atm of pure nitrogen carrier gas. The apparent pyrolysis activation energy of coorongite (25 kJ/mol) is much lower than those of most kerogens, which are on the order of 130-250 kJ/mol. However, it approaches that reported for a Moroccan marine oil shale, implying similarities in their responses to pyrolysis. Non-isothermal pyrolysis by thermogravimetry coupled with infrared spectroscopy (TG-IR) revealed coorongite to contain a significant amount of alkanes. Molecular analysis of the isothermal pyrolysates by gas chromatography-mass spectrometry (GC-MS) identified a homologous series of normal alkanes and alkenes (C 9-C21), normal ketones (C8-C12), alkylaromatic compounds, carboxylic acids, and phenols. Structural group quantitation by nuclear magnetic resonance (NMR) and infrared (IR) spectroscopy showed that the pyrolysate is the result of several processes, with thermal decarboxylation forming alkanes, dehydrogenation ± cyclization forming alkenes and aromatic hydrocarbons, and some compounds being products of simple physical volatilization. Complementary analysis of the pyrolysis residues using solid-state 13C NMR and IR revealed that their sp3C-H carbon atoms would also be volatilized if treated by hydrocracking. These results suggest that stockpiled B. braunii may benefit from pyrolytic removal of carboxyl groups prior to further upgrading by hydrocracking and hydrogenation. © 2012 American Chemical Society.Leonito O. Garciano, Nguyen H. Tran, G.S. Kamali Kannangara, Adriyan S. Milev, Michael A. Wilson, David M. McKirdy and P. Anthony Hal
Crop Updates 1999 - Pulse Research and Industry Development in Western Australia
This session covers seventy three papers from different authors.
CONTRIBUTORS
BACKGROUND
SUMMARY OF PREVIOUS RESULTS
1997 REGIONAL ROUNDUP
Northern Wheatbelt, Bill O’Neill, Agriculture Western Australia
Central Wheatbelt, Jeff Russell, Agriculture Western Australia
Great Southern and Lakes, Neil Brandon, Agriculture Western Australia
Esperance Mallee, Mark Seymour, Agriculture Western Australia
PULSE BREEDING AND AGRONOMY
Faba Bean
Variety evaluation
Germplasm evaluation
Genotypic variation in waterlogging tolerance, Stephen Loss, Tim Colmer and Tim Pope University of WA
Sowing rate
Sowing rate demonstrations, Bill O’Neill, Agriculture Western Australia
Swathing
Effect of seed source on early vigour, Stephen Loss, and Tim Pope University of WA
Phosphorus nutrition
Phosphorus x zinc interactions
Desi chichpea
Breeding highlights, Tanveer Khan, Centre for Legumes in Mediterranean Agriculture
Germplasm evaluation
Variety testing
Drought tolerance, Neil Turner, Laurent Leport, Bob French, Mike Barr, Christine Ludwig, Rebecca Kenny, Tanveer Khan, and K.H.M. Siddique, Centre for Legumes in Mediterranean Agriculture, Ashley Corbet and Ivan Mock, Agriculture Victoria, and Colin Edmonson, South Australian Research and Development Institute
Remobilised carbon and nitrogen: Significance for seed size and yield, Stephen Davies, Neil Turner K.H.M. Siddique and Julie Plumber, Centre for legumes in Mediterranean Agriculture
Molecular markers for cold tolerance and insect resistance Heather Clarke, Centre for legumes in Mediterranean Agriculture
Time of sowing
22. Sowing rate
23. Sowing rate demonstrations, Bill O’Neill, Jason Brady Agriculture Western Australia
Kabuli chickpea
24. Germplasm evaluation
25. Kabuli research in the Ord Irrigation Area, K.H.M. Siddique, Bob Dhackles and Joe Sherrard, Agriculture Western Australia
26. International screening for Ascochyta blight resistance, K.H.M. Siddique and Clive Francis, Centre for legumes in Mediterranean Agriculture, N. Acikgoz, AARI, Turkey, R.S. Malholtra, ICARDA, Syria, and E.J. Knights, NSW Ag
27. Sowing rate
28. Response to phosphorus
Field pea
29. Breeding highlights, Tanveer Khan, Agriculture Western Australia
30. Crop variety testing
31. Variety comparison, Quentin Knight SBS IAMA
32. of sowing
33. Standing stubble demonstration, Neil Brandon and Bill O’Neill, Agriculture Western Australia
34. Intercropping canola improves the productivity of field pea, P. Soetedjo and Lionel Martin, Muresk Institute of Agriculture, K.H.M. Siddique, Stephen Loss, Neil Brandon and Bob French, Agriculture Western Australia
35. Peaola demonstration, Jeff Russell, Agriculture Western Australia
Lentil
36. International germplasm evaluation, Jon Clements, K.H.M. Siddique and Clive Francis, Centre for legumes in Mediterranean Agriculture
37. Variety evaluation
38. rate
Vetch
39. Germplasm evaluation
40. Sowing rate
Narbon bean
41. Germplasm evaluation
42. Agronomy, Mark Seymour, Agriculture Western Australia
43. Herbicides, Mark Seymour, Agriculture Western Australia
44. Lathyrus development, Colin Hanbury, and K.H.M. Siddique, Centre for Legumes in Mediterranean Agriculture
45. Species comparison
46. Seed priming
47. Crop desiccation Glen Riethmuller, Stephen Loss and K.H.M. Siddique, Agriculture Western Australia
48. Gypsum Neil Brandon and Stephen Loss, Agriculture Western Australia
49. Antitranspirants
50. Rhizobial inoculant improvement John Howieson, Jane Malden and Ron Yates, Murdoch University
51. Water use in cropping systems David Hall and David Tennant, Agriculture Western Australia
DISEASE AND PEST MANAGEMENT
52. Chocolate spot in faba beans, Bill MacLeod and Mark Sweetingham, Agriculture Western Australia
53. Chocolate spot management
54. Botrytis grey mould of chickpea, Bill MacLeod and Mark Sweetingham, Agriculture Western Australia
55. BGM management
56. Ascochyta in chickpea, Bill MacLeod and Mark Sweetingham, Agriculture Western Australia
57. Chickpea disease survey, Simon McKirdy, Sean Kelly, Sharon Collins and Domminie Wright, Agriculture Western Australia
58. Lentil diseases, Bill MacLeod and Mark Sweetingham, Agriculture Western Australia
59. Ascochyta blight
60. Ascochyta management
61. Botrytis grey mould management
62. Virus disease, Lindrea Latham, Centre for Legumes in Mediterranean Agriculture, Roger Jones, Agriculture Western Australia
63. Alfalfa mosaic virus
64. Alfalfa mosaic and cucumber mosaic virus in lentil
65. Virus survey of faba bean. Field pea and dwarf chickling crops
66. Screening chickpea and lentil for CMV and BTMV
Insect pests
67. Red-legged earth mite, Anyou Liu, James Ridsdill-Smith, Tanveer Khan, K.H.M.Siddique,, Centre for Legumes in Mediterranean Agriculture
68. Aphids and their parasites, Owain Edwards, James Ridsdill-Smith, and Rick Horbury, CSIRO Entomology
69. Budworm resistance in chickpeas, Krishna Mann, James Ridsdill-Smith, Emilio Ghisalberti, and K. Silvasithamparam, Centre for Legumes in Mediterranean Agriculture
70. Native budworm management in pulses and canola, Kevin Walden, Agriculture Western Australia
71. PULSE ADOPTION Amir Abadi and Sally Marsh, University of Western Australia
72. Does risk keep farmers from growing pulses?
73. Best Rotations Daniel Fels, Agriculture Western Australia
ACKNOWLEDGMENTS
PUBLICATION