The Flinders Ranges and its surroundings in South Australia comprise an impressive rugged terrain that rises abruptly from piedmont plains to the east and west and merges into the plains of the Cenozoic Lake Eyre Basi...The Flinders Ranges and its surroundings in South Australia comprise an impressive rugged terrain that rises abruptly from piedmont plains to the east and west and merges into the plains of the Cenozoic Lake Eyre Basin to the north.Folded and faulted Neoproterozoic–Cambrian clastic and carbonate sedimentary rocks of the Adelaide Geosyncline(Adelaide Rift Complex)form the predominant geology of the ranges and record varied depositional environments and metamorphic overprints and have had a complex landscape history,resulting in a diverse regolith.This ancient,arid terrain represents some of the best analogue landscapes and settings in Australia to observe features and processes fundamental to the evolution of the Earth.The strata of the Flinders Ranges record the evolution of terrestrial surface environments and the biosphere through the Cryogenian,Ediacaran and Cambrian periods,including evidence for Neoproterozoic glaciations,orbital and rotational dynamics and asteroid impact.The diverse assemblages of stromatolites,ancient and modern hydrothermal systems,and alteration assemblages provide field laboratories for astrobiological and hyperspectral research and training.For these reasons the northern Flinders Ranges near Arkaroola have been selected as a site for multi-disciplinary Mars analogue research and space education.展开更多
The lower Cambrian sediments of the Flinders Ranges,South Australia can be divided into three sequence sets.They rest unconformably on the Ediacaran succession.Sequence set C–1 comprises lower clastic units overlain ...The lower Cambrian sediments of the Flinders Ranges,South Australia can be divided into three sequence sets.They rest unconformably on the Ediacaran succession.Sequence set C–1 comprises lower clastic units overlain by a carbonate dominated marine succession that shows marked lateral and vertical facies changes.Sequence sets C–2 and C–3 together comprise a largely clastic dominated succession of marginal marine to nonmarine sediments with subordinate shallow marine carbonates.Sequence set C–1 is richly fossiliferous at some levels with biostratigraphy established for trilobites,archaeocyaths,brachiopods,small shelly fossils,acritarchs and molluscs.The Emu Bay Shale Lagerstätte(Cambrian Series 2)from the north coast of Kangaroo Island occurs within a clastic-rich shelf succession dominated by conglomerate and sandstone.The fossil content is dominated by trilobites in terms of relative abundance and currently over 50 taxa are known including,Anomalocaris,the bivalved arthropods Isoxys and Tuzoia,the nektaspids Emucaris and Kangacaris,the megacheiran Oestokerkus amongst a variety of other arthropods.Other common taxa include palaeoscolecid worms,Myoscolex,sponges,hyoliths,brachiopods,a vetulicolian and several other enigmatic forms.The oldest known well preserved complex arthropod eyes occur in this biota.展开更多
This brief review discusses the behavioral consequences of two pharmacologically selected lines of rats. Flinders Sensitive (FSL) and Flinders Resistant (FRL) Lines of rats were selected on the basis of differential h...This brief review discusses the behavioral consequences of two pharmacologically selected lines of rats. Flinders Sensitive (FSL) and Flinders Resistant (FRL) Lines of rats were selected on the basis of differential hypothermic and behavioral responses to the anticholinesterase, diisopropylfluorophosphate (DFP). FSL rats are more sensitive to the hypothermic effects of cholinergic, serotonergic, and dopaminergic agonists but less sensitive to the locomotor or stereotypic effects of dopamine agonists. FSL rats exhibit greater immobility in the forced swim test and reduced social interaction compared with FRL rats, but do not differ in saccharin intake, behavior in the elevated plus maze, or responses for rewarding brain self-stimulation. The exaggerated immobility and reduced social interaction are counteracted by chronic treatment with antidepressants. Because FSL rats were more sensitive to 5-HT1A receptor agonists, high (HDS) and low (LDS) 8-OH-DPATsensitive lines were selectively bred for differential hypothermic responses to the 5-HT1A receptor agonist, 8-hydroxy-2-(di-N-propylamino)tetralin (8-OH-DPAT). HDS rats were also more sensitive to the hypothermic effects of oxotremorine, a cholinergic agonist, but selection for this response did not diverge with later selection. HDS rats exhibited greater immobility in the forced swim test than LDS rats and this correlated response could be seen early in selection (generation 3). HDS rats also showed reduced social interaction compared to LDS rats, but did not differ in behavior in the elevated plus maze. These findings confirm that selection for hypothermic responses to pharmacological agents do have behavioral consequences, notably the production of depressive-like phenotypes, which can be counteracted by chronic antidepressant treatment. Because increased 5-HT1A receptor sensitivity was common to both selected lines (FSL and HDS), neurobiological processes dependent on this receptor could contribute to the abnormal behaviors that manifest in these rat lines and thus suggesting a mechanism underlying depressive behaviors in humans. However, available human data are inconsistent with this hypothesis and suggest that other mechanisms underlie these behavioral abnormalities in HDS and FSL rats. These mechanisms as well as additional behavioral testing in these rat lines will be discussed.展开更多
文摘The Flinders Ranges and its surroundings in South Australia comprise an impressive rugged terrain that rises abruptly from piedmont plains to the east and west and merges into the plains of the Cenozoic Lake Eyre Basin to the north.Folded and faulted Neoproterozoic–Cambrian clastic and carbonate sedimentary rocks of the Adelaide Geosyncline(Adelaide Rift Complex)form the predominant geology of the ranges and record varied depositional environments and metamorphic overprints and have had a complex landscape history,resulting in a diverse regolith.This ancient,arid terrain represents some of the best analogue landscapes and settings in Australia to observe features and processes fundamental to the evolution of the Earth.The strata of the Flinders Ranges record the evolution of terrestrial surface environments and the biosphere through the Cryogenian,Ediacaran and Cambrian periods,including evidence for Neoproterozoic glaciations,orbital and rotational dynamics and asteroid impact.The diverse assemblages of stromatolites,ancient and modern hydrothermal systems,and alteration assemblages provide field laboratories for astrobiological and hyperspectral research and training.For these reasons the northern Flinders Ranges near Arkaroola have been selected as a site for multi-disciplinary Mars analogue research and space education.
文摘The lower Cambrian sediments of the Flinders Ranges,South Australia can be divided into three sequence sets.They rest unconformably on the Ediacaran succession.Sequence set C–1 comprises lower clastic units overlain by a carbonate dominated marine succession that shows marked lateral and vertical facies changes.Sequence sets C–2 and C–3 together comprise a largely clastic dominated succession of marginal marine to nonmarine sediments with subordinate shallow marine carbonates.Sequence set C–1 is richly fossiliferous at some levels with biostratigraphy established for trilobites,archaeocyaths,brachiopods,small shelly fossils,acritarchs and molluscs.The Emu Bay Shale Lagerstätte(Cambrian Series 2)from the north coast of Kangaroo Island occurs within a clastic-rich shelf succession dominated by conglomerate and sandstone.The fossil content is dominated by trilobites in terms of relative abundance and currently over 50 taxa are known including,Anomalocaris,the bivalved arthropods Isoxys and Tuzoia,the nektaspids Emucaris and Kangacaris,the megacheiran Oestokerkus amongst a variety of other arthropods.Other common taxa include palaeoscolecid worms,Myoscolex,sponges,hyoliths,brachiopods,a vetulicolian and several other enigmatic forms.The oldest known well preserved complex arthropod eyes occur in this biota.
文摘This brief review discusses the behavioral consequences of two pharmacologically selected lines of rats. Flinders Sensitive (FSL) and Flinders Resistant (FRL) Lines of rats were selected on the basis of differential hypothermic and behavioral responses to the anticholinesterase, diisopropylfluorophosphate (DFP). FSL rats are more sensitive to the hypothermic effects of cholinergic, serotonergic, and dopaminergic agonists but less sensitive to the locomotor or stereotypic effects of dopamine agonists. FSL rats exhibit greater immobility in the forced swim test and reduced social interaction compared with FRL rats, but do not differ in saccharin intake, behavior in the elevated plus maze, or responses for rewarding brain self-stimulation. The exaggerated immobility and reduced social interaction are counteracted by chronic treatment with antidepressants. Because FSL rats were more sensitive to 5-HT1A receptor agonists, high (HDS) and low (LDS) 8-OH-DPATsensitive lines were selectively bred for differential hypothermic responses to the 5-HT1A receptor agonist, 8-hydroxy-2-(di-N-propylamino)tetralin (8-OH-DPAT). HDS rats were also more sensitive to the hypothermic effects of oxotremorine, a cholinergic agonist, but selection for this response did not diverge with later selection. HDS rats exhibited greater immobility in the forced swim test than LDS rats and this correlated response could be seen early in selection (generation 3). HDS rats also showed reduced social interaction compared to LDS rats, but did not differ in behavior in the elevated plus maze. These findings confirm that selection for hypothermic responses to pharmacological agents do have behavioral consequences, notably the production of depressive-like phenotypes, which can be counteracted by chronic antidepressant treatment. Because increased 5-HT1A receptor sensitivity was common to both selected lines (FSL and HDS), neurobiological processes dependent on this receptor could contribute to the abnormal behaviors that manifest in these rat lines and thus suggesting a mechanism underlying depressive behaviors in humans. However, available human data are inconsistent with this hypothesis and suggest that other mechanisms underlie these behavioral abnormalities in HDS and FSL rats. These mechanisms as well as additional behavioral testing in these rat lines will be discussed.
