Evolution and variability of the Asian monsoon and its potential linkage with uplift of the Himalaya and Tibetan Plateau

© 2016, Tada et al. Uplift of the Himalaya and Tibetan Plateau (HTP) and its linkage with the evolution of the Asian monsoon has been regarded as a typical example of a tectonic–climate linkage. Although this linkage remains unproven because of insufficient data, our understanding has greatly advanced in the past decade. It is thus timely to summarize our knowledge of the uplift history of the HTP, the results of relevant climate simulations, and spatiotemporal changes in the Indian and East Asian monsoons since the late Eocene. Three major pulses of the HTP uplift have become evident: (1) uplift of the southern and central Tibetan Plateau (TP) at ca. 40–35 Ma, (2) uplift of the northern TP at ca. 25–20 Ma, and (3) uplift of the northeastern to eastern TP at ca. 15–10 Ma. Modeling predictions suggest that (i) uplift of the southern and central TP should have intensified the Indian summer monsoon (ISM) and the Somali Jet at 40–35 Ma; (ii) uplift of the northern TP should have intensified the East Asian summer monsoon (EASM) and East Asian winter monsoon (EAWM), as well as the desertification of inland Asia at 25–20 Ma; and (iii) uplift of the northeastern and eastern TP should have further intensified the EASM and EAWM at 15–10 Ma. We tested these predictions by comparing them with paleoclimate data for the time intervals of interest. There are insufficient paleoclimate data to test whether the ISM and Somali Jet intensified with the uplift of the southern and central TP at 40–35 Ma, but it is possible that such uplift enhanced erosion and weathering that drew down atmospheric CO2 and resulted in global cooling. There is good evidence that the EASM and EAWM intensified, and desertification started in inland Asia at 25–20 Ma in association with the uplift of the northern TP. The impact of the uplift of the northeastern and eastern TP on the Asian monsoon at 15–10 Ma is difficult to evaluate because that interval was also a time of global cooling and Antarctic glaciation that might also have influenced the intensity of the Asian monsoon

Abscess Formation of the Round Ligament of the Liver: Report of a Case

Abscess formation of the round ligament of the liver is very rare. We report a case of a 70-year-old female with abscess of the round ligament after an endoscopic papillotomy for choledocholithiasis. On the 21st day following papillotomy, abscess formation of the round ligament was found by ultrasonographic examination. Surgical treatment was performed because conservative therapy was not effective. The purulent fluid and necrotic tissue at the round ligament were completely removed. Cultures obtained from the abscess grew Staphylococcus epidermidis, but the mechanism of abscess formation in this case remains unclear.</p

IODP New Ventures in Exploring Scientific Targets (INVEST): Defining the New Goals of an International Drilling Program

No abstract available. <br><br> doi:<a href="http://dx.doi.org/10.2204/iodp.sd.9.12.2010" target="_blank">10.2204/iodp.sd.9.12.2010</a

Deformed fields and Moyal construction of deformed super Virasoro algebra

Studied is the deformation of super Virasoro algebra proposed by Belov and Chaltikhian. Starting from abstract realizations in terms of the FFZ type generators, various connections of them to other realizations are shown, especially to deformed field representations, whose bosonic part generator is recently reported as a deformed string theory on a noncommutative world-sheet. The deformed Virasoro generators can also be expressed in terms of ordinary free fields in a highly nontrivial way.Comment: neutral fields are replaced by complex fields almost everywhere in Sects. 6 and

Anomalous negative excursion of carbon isotope in organic carbon after the last Paleoproterozoic glaciation in North America

Early Paleoproterozoic time (2.5–2.0 Ga) spanned a critical phase in Earth's history, characterized by repeated glaciations and an increase in atmospheric oxygen (the Great Oxidation Event (GOE)). Following the last and most intense glaciation of this period, marine carbonates record a large positive excursion of δ^(13)C value (termed the “Lomagundi event”) between about 2.2 and 2.1 Ga coinciding with the global appearances of red beds and sulfates, which suggest an accumulation of high levels of atmospheric oxygen. Here we report the discovery of large negative excursions of δ^(13)C in organic matter (down to −55‰) from quartzose sandstones (of the Marquette Range and the Huronian Supergroups, North America) intermediate in age between the last Paleoproterozoic glaciation and the possible onset of the Lomagundi event. The negative excursion is concomitant with the appearance of intensely weathered quartzose sandstones, which may represent hot and humid conditions. There are some interpretations that potentially explain the negative excursions: (1) redeposition of older ^(13)C-depleted kerogen, (2) later post-depositional infiltration of oil, (3) active methane productions by methanogens in shallow-marine environments, or (4) dissociation of methane hydrate. If the latter two were the case, they would provide clues for understanding the environmental change connecting the intense glaciation and an increase in oxygen

Controls on luminescence signals in lake sediment cores:A study from Lake Suigetsu, Japan

The luminescence characteristics of sediments are driven by a range of environmental factors and can be used as indicators of both local and regional environmental shifts. Hence, rapid luminescence profiling techniques are increasingly employed during multiproxy analysis of sediment cores, overcoming the practical limitations of traditional (dating) methods. One emerging application of luminescence profiling is in the palaeoenvironmental investigation of lake cores. This study demonstrates the versatility of rapid core profiling using portable optically stimulated luminescence and laboratory profiling techniques for appraising the luminescence characteristics of the Lake Suigetsu (Japan) sediment cores. These techniques were employed across four key time periods, each selected for their unique environmental context and significance on either a local or global scale, in order to identify relationships between down-core luminescence and environmental change. We demonstrate that the luminescence characteristics of the cores are susceptible to a range of environmental perturbations and can therefore act as proxies of past change. Additionally, the quantification of these luminescence signals, alongside an assessment of dose rate variations down-core, supports the notion that future luminescence dating is feasible. The results of this analysis contribute to the wider understanding of the application of luminescence techniques – both profiling and dating – to lake sediment cores

Usefulness of a novel higher brain dysfunction screening test for evaluating higher brain function in healthy persons

To accurately and rapidly screen for higher brain dysfunction, we developed a screening test named the “higher brain dysfunction screening test” (HIBRID-ST). Previous studies have reported a decrease in higher brain function with age. However, whether HIBRID-ST can detect a decrease in higher brain function in healthy persons remains unclear.We aimed to assess the usefulness of HIBRID-ST for evaluating higher brain function in healthy persons. We recruited 60 persons without physiological abnormalities and divided them into six equal groups based on their age (20s−70s). HIBRID-ST addresses orientation, short-term memory, word recall, situational awareness, visual short-term memory, and graphic replication and includes the Trail Making and Kanahiroi tests. There was a significant negative correlation between the participants’ age and their total HIBRID-ST score (ρ= −0.68, p<0.01). The total HIBRID-ST score of participants in their 70s was significantly lower than that of participants in their 20s−60s ; the total HIBRID-ST score of participants in their 60s was significantly lower than that of participants in their 20s−50s. Our findings show that HIBRID-ST accurately detects an age-related decline in higher brain function. Further studies are needed to examine the usefulness of HIBRID-ST in patients with higher brain dysfunction