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- Cohen, Timothy, et al.
(författare)
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Late Quaternary mega-lakes of central Australia: varying moisture sources and increased continental aridity.
- 2010
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Ingår i: <em>EOS Transactions, </em><em>American Geophysical Union</em>, PP31B-1624. San Francisco, USA, Dec. 2010.. - Washington DC : American Geophysical Union.
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Optically stimulated (OSL) and thermoluminescence (TL) ages from relict shorelines, along with accelerator mass spectrometer (AMS) 14C ages from freshwater molluscs reveal a record of mega-lake phases over the late Quaternary for Lake Mega-Frome, situated in the arid zone of South Australia. Additional lacustrine, palynological and terrestrial proxies are used to reconstruct a record that extends as far back as 105 ka and demonstrates that Mega-Frome was last joined to the adjacent mega-Eyre at 50 - 47 ka forming the largest palaeolake on the Australian continent. This time interval for hydrological decline coincides with the arrival of humans on the Australian continent and the demise of the mega-fauna. Since then, Mega-Frome has filled independently at 33 - 31 ka (Heinrich event 3) and at the termination of the Last Glacial Maximum (LGM) to depths far in excess of those seen today (up to 15 - 20 times modern lake volumes). Further evidence of subsequent lake-filling episodes is recorded immediately prior to the Younger Dryas, the mid Holocene and during the medieval climatic anomaly. We present evidence for multiple moisture sources over this time period with lake phases being driven by either an enhanced Southern Ocean circulation or an enhanced tropical moisture source or a combination of both. We show however, that southern hemisphere summer insolation maxima (monsoon proxy) is a poor predictor for past palaeo-lake filling episodes. This is the first palaeohydrological record for a large area of southern semi-arid Australia indicating a progressive shift to more arid conditions throughout the last glacial cycle
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| 2. |
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| 3. |
- Gliganic, Luke A., et al.
(författare)
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Late-Holocene climatic variability indicated by three natural archives in arid southern Australia
- 2014
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Ingår i: The Holocene. - : SAGE Publications. - 0959-6836 .- 1477-0911. ; 24:1, s. 104-117
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Tidskriftsartikel (refereegranskat)abstract
- Three terrestrial climate proxies are used to investigate the evolution of Holocene palaeoenvironments in southern central Australia, all of which present a coherent record of palaeohydrology. Single-grain optically stimulated luminescence from sediments supplemented by C-14 from charcoal and lacustrine shells was obtained to date shoreline deposits (Lake Callabonna) and the adjacent Mt Chambers Creek alluvial fan. Our findings are complemented by a U/Th-based record of speleothem growth in the Mt Chambers Creek catchment, which we interpret to reflect increased precipitation. Together, these archives shed light on the timing of, and possible sources of water for, Holocene pluvial intervals. We identified several phases of elevated lake levels dated at similar to 5.8-5.2, 4.5, 3.5-2.7 and 1 kyr, most of which correspond to fluvial activity resulting from increased precipitation in the adjacent ranges. The enhanced hydrology during phases of the late Holocene likely increased the reliability of resources for regional human populations during a time of reduced winter rainfall. When considered within the framework of the current understanding of Holocene palaeoclimate in central Australia, our data suggest that the pattern of landscape response was broadly synchronous with larger scale climatic variability and punctuated by pluvial periods greater than today.
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| 4. |
- Turcot, Valerie, et al.
(författare)
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Protein-altering variants associated with body mass index implicate pathways that control energy intake and expenditure in obesity
- 2018
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Ingår i: Nature Genetics. - : Nature Publishing Group. - 1061-4036 .- 1546-1718. ; 50:1, s. 26-41
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Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWAS) have identified >250 loci for body mass index (BMI), implicating pathways related to neuronal biology. Most GWAS loci represent clusters of common, noncoding variants from which pinpointing causal genes remains challenging. Here we combined data from 718,734 individuals to discover rare and low-frequency (minor allele frequency (MAF) < 5%) coding variants associated with BMI. We identified 14 coding variants in 13 genes, of which 8 variants were in genes (ZBTB7B, ACHE, RAPGEF3, RAB21, ZFHX3, ENTPD6, ZFR2 and ZNF169) newly implicated in human obesity, 2 variants were in genes (MC4R and KSR2) previously observed to be mutated in extreme obesity and 2 variants were in GIPR. The effect sizes of rare variants are similar to 10 times larger than those of common variants, with the largest effect observed in carriers of an MC4R mutation introducing a stop codon (p.Tyr35Ter, MAF = 0.01%), who weighed similar to 7 kg more than non-carriers. Pathway analyses based on the variants associated with BMI confirm enrichment of neuronal genes and provide new evidence for adipocyte and energy expenditure biology, widening the potential of genetically supported therapeutic targets in obesity.
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