Hydrological variations in central China over the past millennium and their links to the Tropic Pacific and North Atlantic Oceans

Variations of precipitation, aka the Meiyu rain, in East Asian summer monsoon (EASM) domain during the last millennium could help enlighten the hydrological response to future global warming. Here we present a precisely dated and highly resolved stalagmite δ18O record from the Yongxing Cave, central China. Our new record, combined with a previously published one from the same cave, indicates that the Meiyu rain has changed dramatically in association with the global temperature change. In particular, our record shows that the Meiyu rain has been weakened during the Medieval Climate Anomaly (MCA), but intensified during the Little Ice Age (LIA). During the Current Warm Period (CWP), our record indicates a similar weakening of the Meiyu rain. Furthermore, during the MCA and CWP, our records show that the atmospheric precipitation is similarly wet in northern China and similarly dry in central China, but relatively wet during the CWP in southern China. This spatial discrepancy indicates a complicated localized response of the regional precipitation to the anthropogenic forcing. The weakened (intensified) Meiyu rain during the MCA (LIA) matches well with the warm (cold) phases of Northern Hemisphere surface air temperature. This Meiyu rain pattern also corresponds well with the climatic conditions over the Tropical Indo-Pacific warm pool. On the other hand, our record shows a strong association with the North Atlantic climate as well. The reduced (increased) Meiyu rain correlates well with positive (negative) phases of North Atlantic Oscillation. In addition, our record links well with the strong (weak) Atlantic meridional overturning circulation during the MCA (LIA) period. All above-mentioned localized correspondences and remote teleconnections on decadal to centennial timescales indicate that the Meiyu rain is coupled closely with oceanic processes in the Tropical Pacific and North Atlantic Oceans during the MCA and LIA

Was Kaposi’s sarcoma-associated herpesvirus introduced into China via the ancient Silk Road? An evolutionary perspective

Kaposi’s sarcoma-associated herpesvirus (KSHV) has become widely dispersed worldwide since it was first reported in 1994, but the seroprevalence of KSHV varies geographically. KSHV is relatively ubiquitous in Mediterranean areas and the Xinjiang Uygur Autonomous Region, China. The origin of KSHV has long been puzzling. In the present study, we collected and analysed 154 KSHV ORF-K1 sequences obtained from samples originating from Xinjiang, Italy, Greece, Iran and southern Siberia using Bayesian evolutionary analysis in BEAST to test the hypothesis that KSHV was introduced into Xinjiang via the ancient Silk Road. According to the phylogenetic analysis, 72 sequences were subtype A and 82 subtype C, with C2 (n = 56) being the predominant subtype. The times to the most recent common ancestors (tMRCAs) of KSHV were 29,872 years (95% highest probability density [HPD], 26,851–32,760 years) for all analysed sequences and 2037 years (95% HPD, 1843–2229 years) for Xinjiang sequences in particular. The tMRCA of Xinjiang KSHV was exactly matched with the time period of the ancient Silk Road approximately two thousand years ago. This route began in Chang’an, the capital of the Han dynasty of China, and crossed Central Asia, ending in the Roman Empire. The evolution rate of KSHV was slow, with 3.44 × 10−6 substitutions per site per year (95% HPD, 2.26 × 10−6 to 4.71 × 10−6), although 11 codons were discovered to be under positive selection pressure. The geographic distances from Italy to Iran and Xinjiang are more than 4000 and 7000 kilometres, respectively, but no explicit relationship between genetic distance and geographic distance was detected

Variations in the East Asian summer monsoon over the past 1 millennium and their links to the Tropic Pacific and North 2 Atlantic oceans

Variations of East Asian summer monsoon (EASM) during the last millennium could help enlighten the monsoonal response to future global warming. Here we present a precisely dated and highly resolved stalagmite δ18O record from the Yongxing Cave, central China. Our new record, combined with a previously published one from the same cave, indicates that the EASM has changed dramatically in association with the global temperature rising. In particular, our record shows that the EASM has intensified during the Medieval Climate Anomaly (MCA) and the Current Warm Period (CWP) but weakened during the Little Ice Age (LIA). We find that the EASM intensity is similar during the MCA and CWP periods in both northern and central China, but relatively stronger during the CWP in southern China. This discrepancy indicates a complicated regional response of the EASM to the anthropogenic forcing. The intensified and weakened EASM during the MCA and LIA matches well with the warm and cold phases of Northern Hemisphere surface air temperature, respectively. This EASM pattern also corresponds well with the rainfall over the tropical Indo-Pacific warm pool. Surprisingly, our record shows a strong association with the North Atlantic climate as well. The intensified (weakened) EASM correlates well with positive (negative) phases of North Atlantic Oscillation. In addition, our record links well with the strong (weak) Atlantic meridional overturning circulation during the MCA (LIA) period. All above-mentioned correlations indicate that the EASM tightly couples with oceanic processes in the tropical Pacific and North Atlantic oceans during the MCA and LIA

Alterations in cell growth and signaling in ErbB3 binding protein-1 (Ebp1) deficient mice

<p>Abstract</p> <p>Background</p> <p>The ErbB3 binding protein-1 (Ebp1) belongs to a family of DNA/RNA binding proteins implicated in cell growth, apoptosis and differentiation. However, the physiological role of Ebp1 in the whole organism is not known. Therefore, we generated <it>Ebp1</it>-deficient mice carrying a gene trap insertion in intron 2 of the <it>Ebp1 (pa2g4) </it>gene.</p> <p>Results</p> <p>Ebp1^-/-mice were on average 30% smaller than wild type and heterozygous sex matched littermates. Growth retardation was apparent from Day 10 until Day 30. IGF-1 production and IGBP-3 and 4 protein levels were reduced in both embryo fibroblasts and adult knock-out mice. The proliferation of fibroblasts derived from Day 12.5 knock out embryos was also decreased as compared to that of wild type cells. Microarray expression analysis revealed changes in genes important in cell growth including members of the MAPK signal transduction pathway. In addition, the expression or activation of proliferation related genes such as AKT and the androgen receptor, previously demonstrated to be affected by Ebp1 expression <it>in vitro</it>, was altered in adult tissues.</p> <p>Conclusion</p> <p>These results indicate that Ebp1 can affect growth in an animal model, but that the expression of proliferation related genes is cell and context specific. The Ebp1^-/-mouse line represents a new <it>in vivo </it>model to investigate Ebp1 function in the whole organism.</p

A Study on Determining Time-Of-Flight Difference of Overlapping Ultrasonic Signal: Wave-Transform Network

An ultrasonic sensors system is commonly used to measure the wall thickness of buried pipelines in the transportation of oil and gas. The key of the system is to precisely measure time-of-flight difference (TOFD) produced by the reflection of ultrasonic on the inner and outer surfaces of the pipelines. In this paper, based on deep learning, a novel method termed Wave-Transform Network is proposed to tackle the issues. The network consists of two parts: part 1 is designed to separate the potential overlapping ultrasonic echo signals generated from two surfaces, and part 2 is utilized to divide the sample points of each signal into two types corresponding to before and after the arrival time of ultrasonic echo, which can determine the time-of-flight (TOF) of each signal and calculate the thickness of pipelines. Numerical simulation and actual experiments are carried out, and the results show satisfactory performances. Document type: Articl

Different behaviors of organic matter under physical-biological controls in the eastern Indian Ocean

Marine organic matter (OM) pools are the key to understanding biogeochemical cycles and carbon storage, especially under ongoing ocean warming. The tropical eastern Indian Ocean (IO) is ideal for unraveling marine OM pools for being one of the least understood ocean basins in terms of its complex physical and biogeochemical dynamics. So far, OM transformation and export remain underexplored and enigmatic in the IO. Here, we integrated in situ observations and incubation experiments in the Central IO (CIO) and Bay of Bengal (BoB). A large OM pool was found in the CIO, where we emphasized the prominent contribution of production in the deep euphotic layer, with physical forcing seasonally playing a supporting role. The dissolved organic matter (DOM)-degradation experiment results revealed high efficiency of in situ DOM consumption in the BoB, whereas dark carbon fixation by ammonia-oxidizing microorganisms was considered an alternative strategy in the euphotic CIO. Water mixing was found to highly influence the OM pools in the mesopelagic waters in the tropical eastern IO, but active microbial respiration could also regulate the OM degradation in the CIO. Our results emphasized the heterogeneity of OM pools between the BoB and CIO, and stated their different regulators of carbon reservoir considering an ocean warming scenario