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This paper introduces a new way to extract a set of representative points from a continuous distribution, which focuses on a method where the selection of points is essentially deterministic, with an emphasis on achieving accurate approximation when the size of points is small. These points are generated by minimizing the Kullback–Leibler divergence, which is an information-based measure of the disparity between two probability distributions. We refer to these points as Kullback–Leibler points. Based on the link between the total variation and the Kullback–Leibler divergence, we prove that the empirical distribution of Kullback–Leibler points converges to the target distribution. Additionally, we illustrate that Kullback–Leibler points have advantages in simulations when compared with representative points generated by Monte Carlo or other representative points methods. In addition, to prevent the frequent evaluation of complex functions, a sequential version of Kullback–Leibler points is proposed, which adaptively updates the representative points by learning about the complex or unknown functions sequentially. Two potential applications of Kullback-Leibler points in simulation of complex probability densities and optimization of complex response surfaces are discussed and demonstrated with examples. [ABSTRACT FROM AUTHOR]

Intrahepatic cholestasis of pregnancy (ICP) is a female pregnancy-specific disorder that is characterized by increased serum bile acid and adverse fetal outcomes. The aetiology and mechanism of ICP are poorly understood; thus, existing therapies have been largely empiric. Here we show that the gut microbiome differed significantly between individuals with ICP and healthy pregnant women, and that colonization with gut microbiome from ICP patients was sufficient to induce cholestasis in mice. The gut microbiomes of ICP patients were primarily characterized by Bacteroides fragilis (B. fragilis), and B. fragilis was able to promote ICP by inhibiting FXR signaling via its BSH activity to modulate bile acid metabolism. B. fragilis-mediated FXR signaling inhibition was responsible for excessive bile acid synthesis and interrupted hepatic bile excretion to ultimately promote the initiation of ICP. We propose that modulation of the gut microbiota-bile acid-FXR axis may be of value for ICP treatment. Intrahepatic cholestasis of pregnancy (ICP) is a liver disease that sometimes develops during pregnancy and is characterized by increased serum bile acid levels. Here the authors report that the gut microbiome species B. fragilis is enriched in patients with ICP and promotes ICP development in mice via inhibition of signalling though the bile acid receptor FXR. [ABSTRACT FROM AUTHOR]

Nonalcoholic steatohepatitis (NASH) has been linked with the gut-liver axis. Here, we investigate the potential for repurposing disulfiram (DSF), a drug commonly used to treat chronic alcoholism, for NASH. Using a mouse model, we show that DSF ameliorates NASH in a gut microbiota-dependent manner. DSF modulates the gut microbiota and directly inhibits the growth of Clostridium. Administration of Clostridium abolishes the ameliorating effects of DSF on NASH. Mechanistically, DSF reduces Clostridium-mediated 7α-dehydroxylation activity to suppress secondary bile acid biosynthesis, which in turn activates hepatic farnesoid X receptor signaling to ameliorate NASH. To assess the effect of DSF on human gut microbiota, we performed a self-controlled clinical trial (ChiCTR2100048035), including 23 healthy volunteers who received 250 mg-qd DSF for 7 days. The primary objective outcomes were to assess the effects of the intervention on the diversity, composition and functional profile of gut microbiota. The pilot study shows that DSF also reduces Clostridium-mediated 7α-dehydroxylation activity. All volunteers tolerated DSF well and there were no serious adverse events in the 7-day follow-up period. Transferring fecal microbiota obtained from DSF-treated humans into germ-free mice ameliorates NASH. Collectively, the observations of similar ameliorating effects of DSF on mice and humans suggest that DSF ameliorates NASH by modulating the gut microbiota and bile acid metabolism. Nonalcoholic steatohepatitis (NASH) has been linked with the gut-liver axis. Here, the authors show that disulfiram (DSF) reduces Clostridium-mediated 7α-dehydroxylation activity to suppress secondary bile acid biosynthesis and ameliorate NASH in mice, and validate DSF regulation of the gut-liver axis in healthy men in a self-controlled clinical trial. [ABSTRACT FROM AUTHOR]

This research investigated eight stations in Clarion-Clipperton Fracture Zone (CCFZ) in the eastern tropical Pacific in 2017 to study the spatial distribution characteristics of nutrients and chlorophyll a (Chl a) concentration, and compared nutrient concentrations and molar ratios with those of other investigations 20 years ago in the same area. The study found that dissolved inorganic nutrient (N, P and Si) concentrations were lowest in the upper layer, and increased from surface to some depths, then they decreased a little to the bottom. N was the limited nutrient factor for the growth of phytoplankton community. Although nutrient concentrations and molar ratios have no obvious changes in 2017 comparing those in 1998–2003, supplemented from the equatorial Pacific, nutrient concentrations in the study area were higher than those in seamounts in the North Pacific and Station ALOHA. Furthermore, this study used Generalized Additive Models (GAMs) to infer the underlying bottom-up factors controlling phytoplankton abundance (Chl a concentration), showing that depth, salinity and PO43−-P concentration were major factors controlling the growth of phytoplankton community. Furthermore, this study can provide basic data and theoretical support for the development of polymetallic nodule area and its long-term impact assessment on the environment. [ABSTRACT FROM AUTHOR]

Environmentally friendly aqueous zinc-ion batteries (AZIBs) have unique advantages, safer and less flammable than lithium-ion battery and lead acid batteries. The crucial issue is the poor mechanical stability and low electronic conductivity, resulting in insufficient rate capability and shortened cycle life. In this paper, by thermal-decomposition of polyaniline (PANI) at high temperature, the nitrogen-doped carbon (NDC) is formed and doped in zinc pyrovanadate (ZVO) nanowires. According to theoretical simulation, after doped by NDC the band gap of ZVO is greatly decreased and the structure stability is increased. As a result, the ZVO/NDC as cathode demonstrates large capacity of 295 mAh g−1 at the 0.1 A g−1 current density and a high-rate capability. In addition, ZVO/NDC nanowires also show a fairly large mass energy density of 132.8 mWh kg−1 and a volumetric energy density of 39.84 mWh L−1, along with a high long-term stability (91% retention after 5000 charge–discharge cycling at 1.0 A g−1). The present work certifies the proof-of-concept that exploiting nitrogen-rich carbon-doped electrodes for AZIBs in the future electronics. [ABSTRACT FROM AUTHOR]

Surrounded by emerging markets with considerable plastic consumption, the South China Sea has been a focus area of microplastic research. A survey on the floating microplastics (> 0.3 mm) and microplastics ingested by fish and mollusks was conducted around three remote islands here. Compared with the results from several previous studies, a high abundance of floating microplastics (with a median of 1.9 × 105 items/km2 or 0.7 items/m3) was observed, revealing another “hot spot” for microplastics. Polyolefin, especially polypropylene, was the main component. The diversity index and evenness index were calculated and evaluated based on the composition of microplastics. The characteristic peaks of Raman spectra concerning pigmented microplastics were provided. Transparent sheets/films were predominant in the water sample, which was quite different from a similar study in this sea area (8.9% for film), and only 16.4% of floating microplastics (> 0.3 mm) were fibers/lines, implying that the main sources of floating microplastics (> 0.3 mm) might be household/agricultural consumption activities. The transparent fiber/line was also dominant in organisms. It is suggested that the main sources of microplastics ingested by organisms might be both fabric fibers and fishing/aquaculture. [ABSTRACT FROM AUTHOR]

Abnormal expression of human telomerase reverse transcriptase (hTERT) has been widely identified in tumors, but the relevant mechanism is not well known. This study aims to investigate the role and mechanism of hTERT in gastric cancer metastasis. Gastric cancer and adjacent non-tumor tissues were collected and the expression levels of hTERT and Gli1 were detected by immunohistochemistry. The results demonstrated that hTERT and Gli1 expression levels in gastric cancer tissue were significantly higher than adjacent non-tumor tissues. Western blot and quantitative real-time PCR were used to an identified expression of the related protein in BGC-823 and SGC-7901 cells. The interactions between hTERT and Sp1 were tested by co-immunoprecipitation experiments. Chromatin immunoprecipitation was performed to confirm that Sp1 and hTERT could bind to the Gli1 promoter. Chromatin reimmunoprecipitation assay further demonstrated that both hTERT and Sp1 bind to the Sp1 site of the Gli1 promoter. Moreover, the hTERT, Sp1, and Gli1 were upregulate was verified in human gastric cancer tissues. These results showed that the expression levels of hTERT in GC tissues were strongly closed to the depth of invasion, lymph node metastasis, TNM (tumor, node, metastasis) stage, and distant metastasis. By combining Sp1 and Gli1 promoter, hTERT upregulated Gli1 expression and promoted invasion and metastasis of GC cells. Overall, these data provide a new molecular mechanism of hTERT to promotes gastric cancer progression. Targeting the hTERT/Sp1/Gli1 axis may represent a new therapeutic strategy. [ABSTRACT FROM AUTHOR]

Flower-like carbon and nitrogen atomic doped NiO nanocomposite (CN-NiO) has been derived from the Ni-MOF/polyaniline (PANI) calcined at high temperature, which is used to construct a nonenzymic electrochemical sensor by coating it on glassy carbon electrode (GCE). The results of electrochemical tests show that the CN-NiO@GCE has the linear dependency of current response on glucose concentration ranged from 5.0 × 10–7 to 3 × 10–3 mol/L. It has higher sensitivity (1144 μA/mM/cm2) and lower detection limit (5.0 × 10–7 mol/L). In addition, the resulting CN-NiO@GCE shows long-term stability. At the same time, this electrode has good selectivity, with no electrochemical response to the interfering concomitant such as urea, nifedipine, ascorbic acid and dopamine. It indicates that Ni-MOF-derived CN-doped NiO nanocomposites are good electrochemical sensing materials, which find potential application to fabricate nonenzymic electrochemical recognition and detection devices. [ABSTRACT FROM AUTHOR]

Atomic doping is considered as an effective method to prepare high-active conductivity-improved electrochemical materials. We report the utilization of a three-dimensional hierarchical porous nitrogen-doped carbon–NiCo2O4/CC as the flexible supercapacitor electrodes and recycled biosensor. In a hydrothermal process, three-dimensional hierarchical needle-like NiCo2O4/CC arrays were prepared by one-step, which changed to the mulberry-like morphology after in situ deposition of polyaniline nanoparticles on NiCo2O4/CC. Upon polyaniline carbonization at high temperature, the resulting porous nitrogen-doped carbon–NiCo2O4 showed uniform nanorod networks and dramatic improvements in the electrolyte affinity, penetration and ionic motion. The obtained electrodes display good flexibility and large areal specific capacitance of 3.0 F cm−2 (2520 F g−1) at the current density of 1.0 mA cm−2, with energy density of 171.5 Wh kg−1 and power density of 1118.4 W kg−1. After 10000 cycles, the capacitance retention rate reaches 90.79%. The prepared NiCo2O4-based composites display design novelty and promising applications in the flexible supercapacitors with large capacitance and high stability. [ABSTRACT FROM AUTHOR]

Highlights from the article: Therefore, it was critical to understand the geometry of oil-containing sand bodies (reservoirs), from the viewpoint of lake-basin sedimentation. Thereafter, I completed a study on the relationship between sedimentary characteristics and oil production in sand and gravel reservoirs of the Karamay Oilfield (Wang and Wang 1993). From 1983 to 1985, I carried out a study on the fan delta-turbidity sedimentary system of the rift valley granite basin in the Zhongyuan Oilfield (Wang et al. [16]). 3 Qi YN, Wang SM (1983) A preliminary analysis of the microfacies of sand bodies in several oil-bearing basins of China.

In this paper, multiple hydrogen bonding interaction of ureidopyrimidinone (UPM) was employed as the linking bridge for the formation of a novel porphyrin·multi-walled carbon nanotube (MWNT) hybrid, which was then used to fabricate a layer-by-layer (LbL) film composed of porphyrin-UPM·MWNT-UPM. Both in the assembled hybrid and the LbL film, porphyrin was closely attached to the surface of the MWNT under the strong multiple hydrogen bonding interaction, forming the core-shell structure. In addition, strong electronic communication was observed between porphyrin and MWNT. The hydrogen bonding association behavior between porphyrin-UPM and MWNT-UPM was attentively analyzed by UV-Vis spectra, fluorescent spectra and transmission electron microscope experiments. It was found that the hydrogen bonding interactions were crucial for the formation of the supramolecular hybrid and the LbL film as well as the occurrence of interfacial electronic communication. This result indicated that the introduction of strong noncovalent bonding interaction between donor and acceptor is an appropriate way to control the material structure and facilitate the interfacial electronic communication in the hybrids which lay the groundwork for their application in electrochemical sensors or photovoltaic devices. [ABSTRACT FROM AUTHOR]

Background: Tea polyphenols are the prominent component in tea. After the fermentation process, tea polyphenols are oxidized by polyphenol oxidase to form oxidized tea polyphenols (OTPs). OTPs contain a significant amount of hydrophobic phenyl groups that can bind with non-aqueous materials. Here, we determined whether OTPs can bind with lipids and reduce fat uptake and assessed the effect of OTPs on decreasing obesity and alleviating hyperlipidaemia and other metabolic syndromes. Methods: Rats were divided into three groups: control, high-fat diet (HFD) and OTP groups. The control and HFD groups were fed a chow diet and a high-fat diet, respectively, for 12 weeks; the OTP group was fed a high-fat diet for 6 weeks and then a high-fat diet containing 2 % OTP for 6 weeks. The serum and excrement triglyceride (TAG) and total cholesterol (CHOL) concentrations were determined, and liver tissue and white adipose tissue were collected to detect the expression levels of genes involved in lipid metabolism. Results: Our results revealed that OTPs failed to decrease the serum concentrations of TAG and CHOL. OTPs alleviated the accumulation of lipids in the liver tissue and changed the expression levels of the regulators of lipid metabolism, i.e., peroxisome proliferation-activated receptors ( ppars), compared with the rats fed a high-fat diet alone. We also observed a significantly decreased reduction of weight in the visceral white adipose, enhanced regulation of fatty acid β-oxidation by PPARα and enhanced biosynthesis of mitochondria in the visceral white adipose of the OTP rats compared with the HFD rats. Additionally, OTPs promoted the excretion of lipids. Conclusion: Our results suggest that OTPs alleviate the accumulation of lipids in liver and visceral white adipose tissue and promote lipid excretion in rats in vivo. [ABSTRACT FROM AUTHOR]

Three global datasets, the History Database of the Global Environment (HYDE), Kaplan and Krumhardt (KK) and Pongratz of reconstructed anthropogenic land cover change (ALCC) were introduced and compared in this paper. The HYDE dataset was reconstructed by Goldewijk and his colleagues at the National Institute of Public Health and the Environment in Netherland, covering the past 12 000 years. The KK dataset was reconstructed by Kaplan and his colleagues, the Soil-Vegetation-Atmosphere Research Group at the Institute of Environmental Engineering in Switzerland, covering the past 8000 years. The Pongratz dataset was reconstructed by Pongratz and her colleagues at the Max Planck Institute for Meteorology in Germany, covering AD 800-1992. The results show that the reconstructed datasets are quite different from each other due to the different methods used. The three datasets all allocated the historical ALCC according to human population density. The main reason causing the differences among the three datasets lies on the different relationships between population density and land use used in each reconstructed dataset. The KK dataset is better than the other two datasets for two important reasons. First, it used the nonlinear relationship between population density and land use, while the other two used the linear relationship. Second, Kaplan and his colleagues adopted the technological development and intensification parameters and considered the wood harvesting and the long-term fallow area resulted from shifting cultivation, which were neglected in the reconstructions of the other two datasets. Therefore, the KK dataset is more suitable as one of the anthropogenic forcing fields for climate simulation over the past two millennia that is recently concerned by two projects, the National Basic Research Program and the Strategic and Special Frontier Project of Science and Technology of the Chinese Academy of Sciences. [ABSTRACT FROM AUTHOR]

Using Lanczos filtered simulation results from the ECHO-G coupled ocean-atmosphere model, this study analyzes the spatiotemporal structure of temperature and precipitation on centennial time scale to examine how climate change in eastern China responded to external forcing during the last millennium. The conclusions are (1) eastern China experienced a warm-cold-warm climate transition, and the transition from the warm period to the cold period was slower than the cold to warm transition which followed it. There was more rainfall in the warm periods, and the transitional peak and valley of precipitation lag those of temperature. The effective solar radiation and solar irradiance have significant impacts on the temporal variation of both temperature and precipitation. Volcanic activity plays an important role in the sudden drop of temperature before the Present Warm Period (PWP). There is a positive correlation between precipitation and volcanic activity before 1400 A.D., and a negative relationship between the two thereafter. The concentration of greenhouse gases increases in the PWP, and the temperature and precipitation increase accordingly. (2) The spatial pattern of the first leading empirical orthogonal function (EOF) mode of temperature on centennial time scale is consistent with that on the inter-annual/inter-decadal (IA-ID) time scales; namely, the entirety of eastern China is of the same sign. This pattern has good coherence with effective solar radiation and the concentrations of greenhouse gases. The first leading EOF mode of precipitation on centennial time scale is totally different from that on the IA-ID time scales. The first leading mode of centennial time scale changes consistently over the entirety of eastern China, while the middle and lower reaches of the Yangtze and Yellow Rivers are the opposite to the rest of eastern China is the leading spatial pattern on IA-ID time scale. The distribution of precipitation on centennial time scale is affected by solar irradiance and greenhouse gas concentrations. [ABSTRACT FROM AUTHOR]

Resistive random access memory (RRAM or ReRAM) is a non-volatile memory (NVM) technology that consumes minimal energy while offering sub-nanosecond switching. In addition, the data stability against high temperature and cycling wear is very robust, allowing new NVM applications in a variety of markets (automotive, embedded, storage, RAM). Based on sudden conduction through oxide insulators, the characteristics of RRAM technology have still yet to be fully described. In this paper, we present our current understanding of this very promising technology. [ABSTRACT FROM AUTHOR]

Based on 11004 satellite images from CBERS CCD and Landsat TM/ETM, changes in the spatial characteristics of all lakes in China were determined following pre-established interpretation rules. This dataset was supported by 6843 digital raster images (1:100000 and 1:50000), a countrywide digital vector dataset (1:250000), and historical literature. Comparative data were corrected for seasonal variations using precipitation data. There are presently 2693 natural lakes in China with an area greater than 1.0 km, excluding reservoirs. These lakes are distributed in 28 provinces, autonomous regions and municipalities and have a total area of 81414.6 km, accounting for ∼0.9% of China's total land area. In the past 30 years, the number of newly formed and newly discovered lakes with an area greater than 1.0 km is 60 and 131, respectively. Conversely, 243 lakes have disappeared in this time period. [ABSTRACT FROM AUTHOR]

With the accelerating development of new drugs, there is a great need for rapid and simple screening technologies for estimating the potential toxicity of new compounds. LD50 determination is the main way to measure the acute toxicity of all types of substances. In this paper, a new in vitro method, biopartitioning micellar chromatography, was developed for predicting oral acute toxicity (LD50) based on the similar properties between biopartitioning micellar chromatography systems and biological barriers and extracellular fluids. A second-order polynomial model (an LD50 model) has been obtained using the retention data of the dihydropyridine selective calcium channel antagonists to predict the pharmacological toxicity of the same compounds. [ABSTRACT FROM AUTHOR]

Multifold palynological diversity indices calculated by pollen data of the Heqing deep drilling core are synthetically analyzed, the results show that the plant diversity rapidly increased and its fluctuant amplitude and frequency evidently largened during the stages of 2.729-2.608 Ma, 1.176-0.342 Ma and since 0.118 Ma respectively, while during the other periods the plant diversity was relatively low with a gentle fluctuation. To discuss further the relation between ancient plant diversity and paleoenvironment, it is considered that the plant diversity in the Heqing region lies on increase or decrease of vertical vegetational belts in mountains around the studied area and richness of components of these vegetational belts, and is controlled by amplitude of tectonic uplift of mountains and climatic changes. The high plant diversity during 2.729-2.608 Ma responded to the strong uplift of mountains at the stage, while the plant diversity greatly increased and its fluctuant amplitude and frequency markedly largened at about 1.176 Ma was obviously response to the Middle Pleistocene Transition. The plant diversity and its fluctuant amplitude and frequency increased further at about 0.991 Ma may be superposably affected by both the Middle Pleistocene Transition and the tectonic uplift. The plant diversity increased since 0.118 Ma may indicate that the southwest monsoon strengthened and humid climate more fitted many kinds of plants to grow. [ABSTRACT FROM AUTHOR]

The commonality and difference in the variations of temperature and precipitation between the Northern Hemisphere (NH) and Southern Hemispheres (SH) in the last millennium are investigated by analysis of the millennium simulation with the ECHO-G coupled climate model. The NH mean temperature variations are generally consistent with those of the SH counterpart on the interannual, decadal and centennial time scales. But, the transition times between the medieval warm period (MWP), the little ice age (LIA), and the present-day warm period (PWP) in the NH leads that in the SH; and the anomaly amplitude in the NH is significantly larger than the SH counterpart. For the precipitation variations, the NH mean precipitation varies in-phase with the SH mean precipitation on decadal and centennial scales (mainly in the mid-high latitudes) but out-of-phase on the interannual scale (mainly in the low latitudes). During the MWP the warming has comparable amplitude in the NH and SH; however, during the PWP the NH warming is considerably stronger than the SH warming. Further, the present-day temperature rises in the NH high latitudes but decreases in the SH high latitudes, which is very different from the warming pattern during the MWP. Since during the MWP the greenhouse gases (GHG) concentration stayed at a low level, we infer that the present-day opposite temperature tendency in the high latitudes between the two hemispheres may be related to the increase of the GHG concentration. [ABSTRACT FROM AUTHOR]

Multi-proxies of lacustrine sediments, such as total carbon (TC), total organic carbon (TOC), total inorganic carbon (TIC), total nitrogen (TN), total sulfur (TS), hydrogen index (HI), oxygen index (OI) and stable carbon isotopic composition of organic matter ( δ 13Corg), were analyzed using a 7.3 m core from Zigê Tangco. The source of the organic matter in the sediment was mainly from autochthonous phytoplankton, therefore the significances of proxies can be interpreted as that high TOC, TOC/TS, HI and δ 13Corg values, low TC, TIC values corresponded to warm and wet climatic condition, and vice versa. The process of climatic development in the Zigê Tangco region was hence recovered. During the early and Mid-Holocene, the climate was warm and wet and intensive cold events occurred during the periods of 8600 to 8400 cal a BP and 7400 to 7000 cal a BP. In the second half of Holocene, the climate became cold and dry gradually. The palaeoclimatic process during Holocene in Zigê Tangco region matched well with that in Co Ngoin region which is ca 40 km to the south-east. Therefore this palaeoclimatic process represents the Holocene climatic feature in the Central Tibetan Plateau which has the same pattern in the Northern Tibetan Plateau, but the time and duration of some climatic events might be different. We can conclude that in Holocene solar insolation controlled the climatic pattern on the central Tibetan Plateau. [ABSTRACT FROM AUTHOR]

The high-resolution pollen study of a 737.72-m-long lake sediment core in the Heqing Basin of Yunnan Province shows that the vegetation and climate of mountains around the Heqing Basin went through six obvious changes since 2.780 Ma B.P. Namely, Pinus forest occupied most mountains around the studied area and the structure of vertical vegetational belt was simple between 2.780 and 2.729 Ma B.P., reflecting a relatively warm and dry climate. During 2.729–2.608 Ma B.P., the areas of cold-temperate conifer forest (CTCF) and Tsuga forest increased and the structure of vertical vegetational belt became clear. According to percentages of tropical and subtropical elements growing in low-altitude regions rifely increased, we speculate that the increase of CTCF and Tsuga forest areas mainly resulted from strong uplift of mountains which provided upward expanding space and growing condition for these plants. Thus, the climate of the low-altitude regions around the basin was relatively warm and humid. Between 2.608 and 1.553 Ma B.P., Pinus forest occupied most mountains around the studied area and forest line of CTCF rose, which reflects a moderately warm-dry climate on the whole. During 1.553–0.876 Ma B.P., the structure of vertical vegetational belt in mountains around the studied area became complicated and the amplitude of vegetational belts shifting up and down enlarged, which implies that the amplitude of climatic change increased, the climatic associational feature was more complex and the climate was moderately cold at a majority of the stage. During 0.876–0.252 Ma B.P., there were all vertical vegetational belts existing at present in mountains around the studied area. The elements of each belt were more abundant and complex than earlier. At different periods in the stage vertical vegetational belts occurred as expanding or shrinking, and alternated each other. The amplitude of vegetational belts shifting up and down was the maximum in the whole section. This change suggests that the amplitude of climatic change was evidently larger than earlier, but the frequency reduced and the climatic associational feature was more complex. From 0.252 Ma B.P. to the present, the most time was characteristic of the expanding of Pinus forest and semi-humid evergreen broad-leaved forest (SEBF) in mountains around the studied area, while expanding time of other vegetational belts was very short, which reflects a smaller amplitude of cold and warm fluctuation. On the basis of the six obvious cycles of vegetational and climatic changes, there were still many times of secondary vegetational successions and climatic oscillations. Based on the above analysis, the forcing mechanism of vegetational succession and climatic change in the Heqing Basin is further discussed. It is primarily considered that main influential factors were exterior factors such as orbital parameters, etc., but the uplift of the Qinghai-Tibet Plateau played a very important function for environmental changes in the Heqing Basin at two times obvious increase of vertical vegetational belts and three climatic transitions. [ABSTRACT FROM AUTHOR]

Based on the analysis of carbonate content and loss on ignition for a long sediment core (737 m in length) drilled in Heqing, the orbital scale evolution of the Southwest Monsoon is revealed, by using overlapped spectral analysis and filter methods. It is shown that the obliquity cycle and precession cycle are the key factors for the Southwest Monsoon evolution and that the change of the global ice volume and the uplift of the Qinghai-Tibetan Plateau also impose great influences on it. [ABSTRACT FROM AUTHOR]

Metals in lacustrine sediment have both anthropogenic and natural sources. Because of intensified human activities, the anthropogenic input of metal elements has exceeded the natural variability. How to distinguish the anthropogenic sources in lake sediments is one of the tasks in environmental management. The authors present a case study, which combined the geochemical and statistical methods to distinguish the anthropogenic sources from the natural background. A 56 cm core (core DJ-5) was collected from Dongjiu Lake, Taihu Lake catchment, China. The concentration distributions of Al, Ba, Be, Ca, Cd, Co, Cr, Cu, Fe, K, Li, Mg, Mn, Na, Ni, Pb, Sr, Ti, V and Zn in core DJ-5 indicated that Dongjiu Lake had serious Cd pollution, and the concentrations of Cr, Cu, Pb, Mn and Zn had also exceeded the Chinese State Standards of Soil Environmental Quality in the upper layer of the core. Using Al as a reference element, the other metals were normalized and compared with their baselines to calculate the enrichment factors (EFs). The principal component analysis (PCA) of metal concentrations was performed using ViSta6.4. The results of EFs and PCA indicated that the concentration variations of Cd, Cu, Pb, Mn and Zn were mainly caused by the anthropogenic sources, and the concentration variations of Cr and Ni were influenced by both the anthropogenic and natural factors, while the other metals were mainly derived from the natural sources. Intensified human activities within the lake catchment area resulted in the increase of heavy metal inputs directly and the acceleration of erosion which caused other metal elements to deposit in the aquatic environment. The results of this work will be useful in probing changes forced by humans in the lake environment and in adjusting human activity in restoring the lake environment. [ABSTRACT FROM AUTHOR]

Surficial sediments from 13 sites throughout Lake Taihu, one of the largest urbanized freshwater lake systems in China, were analyzed for biomarkers (e.g., n-alkanes and hopanes) to track the origin of organic inputs (biogenic or anthropogenic), and, thus, to identify any ‘hot spots’ of hydrocarbon contamination. A distinct spatial distribution of aliphatic hydrocarbons in sediments was observed in Lake Taihu. At the northern tip of the lake (i.e., Meiliang and Wuli Bays), the highest mean aliphatic hydrocarbon concentration, with a significant contribution of an unresolved complex mixture (UCM), was found, indicating possible anthropogenic petroleum contamination (mainly from untreated and partially treated industrial and domestic sewage from Wuxi, Changzhou and other cities). This was supported by the n-alkane indices (e.g., small Carbon Preference Index and odd-to-even values) and a high degree of maturity of the hopane biomarkers. However, hydrocarbons from East Taihu were mainly biogenic, with the lowest mean concentrations, negligible or no contribution of UCM, abundance of vascular plant C23–C33 n-alkanes with a high odd-to-even predominance, and the presence of biogenic hopanes (e.g., 17β(H), 21β(H)-hopanes and hopenes). In the other areas of the lake, however, the predominance of biogenic in combination with petrogenic hydrocarbons was indicated by the biomarkers. [ABSTRACT FROM AUTHOR]

The δ18O records of ostracode shells in sediments of core QH-2000 from Qinghai Lake can be used as a better proxy to reflect monsoon changes, Low monsoon precipitation between 17.5 and 11 cal. ka BP is indicated by positive #180 values averaging 2.37‰. A fast shift in #180 from positive at 11 cal, ka BP to negative at 10 cal. ka BP indicates sharp increase of monsoon precipitation. An interval of generally high monsoon precipitation is observed between 10 and 6 cal. ka BP with δ18O values averaging -2,15‰. Decrease of monsoon precipitation between 6 and 2.5 cal. ka BP is indicated by positive δ18O values. δ18O keeps positive values averaging 3.0‰ between 2,5 and 0 cal, ka BP suggesting low high monsoon precipitation. The climatic changes indicated by δ18O records of ostracode shells in sediments of core QH-2000 from Qinghai Lake and our broader regional comparison show that the climate in Qinghai Lake since the late Glacial is probably controlled by southwest monsoon other than southeast monsoon. [ABSTRACT FROM AUTHOR]

Chronology is the basis for using lacustrine sediments to reconstruct the history of environmental change. Radioactive-nuclides such as 14C, 210Pb and 137Cs dating are mainly used to establish the chronology for recent several ten thousand years. Because of being mixed with “dead carbon”, the measured 14C age is always older than the actual age which is recognized as “reservoir effect”. Cs is a kind of active metal element, and easy to migrate vertically in the sediment that leads to the error of the time marker. 210Pb dating should make sure to select CIC model or CRS model. On the Tibetan Plateau, most of the lakes are alkaline closed lake where Cs is more moveable in the sediment and the reservoir effect caused by “dead carbon” on 14C dating is stronger. Based on the analysis on results of 14C, 210Pb and 137Cs of the lacustrine sediments from Co Ngoin, central Tibetan Plateau, we use the simple regression method to re-calculate the 14C calendar ages, and establish the time sequence for cores CE-1 and CE-2 with result of 210Pb CRS model for the upper 35 cm and recalculated 14C calendar age for sediments bellow 35 cm. Since 1400 cal. a BP, sedimentation interrupted for more than 1000 years. According to this time sequence, variations of environmental proxies confidently reflect the major climatic events in Holocene. [ABSTRACT FROM AUTHOR]

The intensive geophysical survey of Qinghai Lake reveals the buried depth of lake sediments and their distribution features. The result indicates that there are three important interphases of Qinghai Lake sediments: T1 is the rife interphase of the lake, above which sediments are spread all over the lake basin with roughly the same thickness; T5 is the interphase from which the neotectonic sedimentary cycle begins, and its above sedimentary environment is relatively stable; Tg is the base of the lake basin. Five west-northwest (WNW) fault belts defined the tectonic structure of Qinghai Lake basin: the central hunch around Haixin Shan with two subbasins both in its north and south. The thickness of the lake sediments varies at different places, the thickest sediments are found within the two subbasins. According to the depth that the Sparker System can reach, sediment in the northern subbasin is deeper than 560 m, while sediment in the southern subbasin is deeper than 700 m. The correlation between the seismic sequence stratigraph and the lithology of onshore core shows that Qinghai Lake sediments consist of muddy silt, clay silt, silty clay, gravel silty clay, etc. [ABSTRACT FROM AUTHOR]

Use of micellar mobile phases in reversed-phase liquid chromatography (RPLC) results in hydrophobic and electrostatic sites for interaction. Modified stationary phases in micellar liquid chromatography (MLC) are structurally similar to biomembranes. To confirm this we focused on the effects of the type and concentration of surfactant (Brij 35, SDS, and CTAB) and mobile phase pH on the retention of antihypertensive drugs on modified C18 stationary phases. Quantitative retention-activity relationships are proposed for the drugs and the different surfactants and compared with those obtained using aqueous–organic mobile phases. Finally, a correlation was obtained between the logarithm of retention factors (log k) and the toxicity (LD50) of antihypertensive drugs. [ABSTRACT FROM AUTHOR]

The evolutions of diatom floras and the total phosphorous (TP) concentrations in the historical period were reconstructed for two lakes, Longgan and Taibai in the middle Yangtze River, based on high resolutional fossil diatom study from two sediment cores and an established regional diatom-TP transfer function. The TP concentration in Longgan Lake changed slightly in the range of 36–62 μg/L and kept its middle trophic level in the past 200 years. The changes of diatom assemblages reflect a macrophyte-dominated history of the lake. During the nineteenth century, the lake TP concentration increased comparatively, corresponding to the increase in abundance of benthic diatoms. The progressive increase of epiphytic diatoms since the onset of the twentieth century indicates the development of aquatic plants, coinciding with the twice drops of water TP level. The TP concentration in Taibai Lake kept a stable status about 50 μg/L before 1953 AD, while diatoms dominated by facultative planktonic Aulacoseira granulata shifted quickly to epiphytic diatom species, indicating a rapid expansion of aquatic vegetation. During 1953–1970 AD, the coverage of aquatic plants decreased greatly inferred by the low abundance of epiphytic diatoms as well as declined planktonic types, and the reconstructed TP concentration shows an obvious rising trend firstly, suggesting the beginning of the lake eutrophication. The lake was in the eutrophic condition after 1970, coinciding with the successive increase of planktonic diatoms. The comparison of the two lakes suggests the internal adjustment and purification function of aquatic plants for nutrients in water. The discrepancy of TP trends in the two lakes after 1960 reflects two different patterns of lake environmental response to human disturbance. Sediments in Taibai Lake clearly recorded the process of lake ecological transformation from the macrophyte-dominated stage to the algae-dominated stage. The limits of TP concentration (68–118 μg/L) in the transitional state can be considered as the critical value between the two stable ecosystems. Further work will be necessary to provide more evidence from the sediments in more eutrophic lakes for the primary inference. The reconstructive TP level and the inference of aquatic plants from fossil diatoms in different lakes, as well as their comparison provide a scientific basis for ecological restoration of eutrophic lakes in research regions. [ABSTRACT FROM AUTHOR]

In this paper, Lake Taihu, a large shallow freshwater lake in China, is chosen as an example of reconstruction of eutrophication through the comparison between stable isotopes from dissolved nutrients and plants and water column nutrient parameters and integration of multiple proxies in a sediment core from Meiliang Bay including TN, TP, TOC, C/N, δ15N, δ13C, etc. Differences in aquatic plant species and trophic status between East Taihu Bay and Meiliang Bay are indicated by their variations in δ13C and δ15N of aquatic plants and δ15N of NH4 +. A significant influence of external nutrient inputs on Meiliang Bay is reflected in temporal changes in δ15N of NH4 + and hydro-environmental parameters. The synchronous change between δ13C and δ15N values of sedimented organic matter (OM) has been attributed to elevated primary production at the beginning of eutrophication between 1950 and 1990, then recent inverse correlation between them has been caused by the uptake of 15N-enriched inorganic nitrogen by phytoplankton grown under eutrophication and subsequent OM decomposition and denitrification in surface sediments, indicating that the lake has suffered from progressive eutrophication since 1990. Based on the use of a combination of stable isotopes and elemental geochemistry, the eutrophication of Meiliang Bay in Lake Taihu could be better traced. These transitions of the lake eutrophication respectively occurring in the 1950s and 1990s have been suggested as a reflection of growing impacts of human activities, which is coincident with the instrumental data. [ABSTRACT FROM AUTHOR]

The sedimentary environment change, trophic evolution and heavy metals pollution history of the northern Taihu Lake in the last 100 years are studied according to the sedimentary geochemical proxies of the core sediments, such as grain size, nutrients, heavy metals, diatom, etc. The nutrients in the sediments depended mainly on the lake internal circulation and the heavy metals were from natural geogenic sources before the 1920s, which were not influenced by human activities generally, and grain size was one of the key factors influencing heavy metals content in the sediments. The alternation of manner and strength of human activities in Taihu Lake catchment before and after the 1920s made the lake sediments coarser, and hence heavy metals and TP content decreased contrasted with that before the 1920s. TP content in sediments and water increased from the 1950s to late 1970s due to anthropogenic pollutants discharge, and the lake belonging to mesotrophic state. TN and TOC content and C/N ratio increased due to the increasing external pollutants into Taihu Lake by human activities, TP content also increased obviously in water and sediments, and the diatom association was dominated by eutrophic species since the late 1970s, indicating the eutrophication state of Taihu Lake in this period. Meanwhile the increasing in heavy metals content, such as Cu, Mn, Ni, Pb and Zn, and their proportion of valid fractions in the sediments indicates that they all result from human pollutants since the late 1970s. The heavy metals in the surface sediments have certain potential biological toxicity due to the higher SEM/AVS ratio. [ABSTRACT FROM AUTHOR]

Based on the total phosphorous (TP) concentration in sediment core, the TP concentration in lake water quantitatively reconstructed from fossil diatoms and diatom-TP transfer function in the Longgan Lake during the last 200 years, the temperature and precipitation data from meteorological observation for the last 50 years, the temperatures and precipitation sequences of climate simulation for the last 200 years, as well as the amount of the agricultural phosphate fertilizer in Longgan area for nearly 50 years, the characteristic and the law of the nutrient status evolution were analyzed, and the influence of the climatic factor, the anthropologic factor and the aquatic biology factor on the nutrient status evolution and its mechanism were discussed for the Longgan Lake during the last 200 years. The results showed that, in the nearly 200 years, the TP concentration in the sediment core of the Longgan Lake gradually increased, its range of variation was situated between 330–580 mg/kg, the mean value was 388 mg/kg, a nearly 30-year vibration adjustment period existed at 1950 around. The TP concentration in lake water changed in a different way. Before 1950, it had a slow increasing tendency in fluctuated background, to 1950 around it reached up to the mean value (52.18 μg/L), and vibrated and adjusted around the mean value, then it fast declined, its change range was situated between 37.75–62.33 μg/L. The analyses indicated that, in the centennial time scale, the climate change was the main controlling factor, while in the decadal time scale in the recent 50 years, human activities were the leading factors for the nutrient status evolution of the Longgan Lake. 60% of the variability of the TP concentration in the sediments and 57% of that in lake water were due to human activities. The differentiation between phosphorus concentration in the sediment and in the lake water reflected the response processes and the adjustment abilities of the lake aquatic ecosystems to the lake nutrient level, implying the maintenance and the destruction of the balances between the algae and the aquatic plants, as well as the corresponding accumulating characteristics of the phosphorus. [ABSTRACT FROM AUTHOR]

By using the data of underwater irradiance measured in the different lake regions of Lake Taihu during 1998–2004 and total suspended solids (TSS), wind speeds of the total 13 stations in typical lake regions during 1993–2003, this paper analyzes the factors of influencing on PAR (photosynthetically available radiation) attenuation, euphotic depth, and presents the temporal and spatial variations of euphotic depth of typical lake regions in Lake Taihu, and the spectral distributions of euphotic depth at station 2. The results show that the concentration of TSS is the most important factor impacting PAR attenuation, followed by chlorophyll a; chromophoric dissolved organic matter (CDOM) has little impact on the PAR euphotic depth. During 1993–2003, the mean yearly PAR euphotic depths of the typical lake regions ranged from 1.04 to 1.95 m with a mean value of 1.35±0.23 m. The PAR euphotic depth fell into 3 spatial zone types: Type I, the lowest, including the lake center and the inflows of rivers; Type II, intermediate, including Meiliang Bay, Wulihu Lake and Gonghu Bay; Type III, the greatest, including the East Lake Taihu; corresponding mean depths were approximately 1.1, 1.4, 2.0 m, respectively. The seasonal variations of euphotic depths were not quite the same in different lake regions. In the lake center, the mean values of PAR euphotic depth in summer and autumn were significantly greater than those in winter and spring; in the Meiliang Bay, winter means were significantly greater than in the other three seasons; in the East Lake Taihu, winter means were significantly less than in the other three seasons. However, no distinct seasonal change was recorded in the Wulihu Lake, Gonghu Bay and the inflows of rivers. The spectral distributions of euphotic depth present a minimal value at the blue light wave band of 400 nm, and a peak at the green light wave band of around 580 nm. In 1998 and 1999, based on the seasonal many-day continuous measurements, the PAR euphotic depths at station 2 were recorded 2.00±0.21, 2.52±0.45, 1.58±0.24, 2.00±0.15 m in spring, summer, autumn and winter, respectively. The peak value of 440 nm absorbed by phytoplankton corresponded to a euphotic depth of only 0.81–1.47 m (mean 1.07±0.29 m), which was much lower than the mean PAR euphotic depth of 1.98±0.41 m. [ABSTRACT FROM AUTHOR]

With high association constants in nonpolar solvents, the quadruple hydrogen bonding arrays of 2-ureido-4[1H]-pyrimidinones are recently considered to be one of the ideal building blocks to construct the complicated and functional supramolecular systems. In this paper, we review the latest achievements of the supramolecular assemblies based on 2-ureido-4[1H]-pyrimidinone AADD quadruple hydrogen bonding building blocks. [ABSTRACT FROM AUTHOR]

The reconstructed temperature anomalies in the eastern China were compared with the output from a 1000-year model simulation in an attempt to evaluate the model’s regional simulation skills and to understand the causes of climate change in China over the last millennium. The reconstructed data are the winter half-year temperature anomalies in the central region of eastern China (25°–40°N, east of 105°E) for the last 1000 years with a 30-year resolution. The model used is the global atmosphere-ocean coupled climate model, ECHO-G, which was driven by time-varying external forcings including solar radiation, volcanic eruptions, and greenhouse gas concentrations (CO2 and CH4) for the same period. The correlation coefficient between the simulated and reconstructed time series is 0.37, which is statistically significant at a confidence level of 97.5%. The Medieval Warm Period (MWP) during 1000–1300 A.D., the Little Ice Age (LIA) during 1300–1850 A.D. and the modern warming period after 1900 A.D. are all recognizable from both the simulated and reconstructed temperatures. The anomalies associated with the LIA and the modern warming simulated by the model are in good consistency with the reconstructed counterpart. In particular during the Maunder sun-spot minimum (1670–1710 A.D.), both the simulated and reconstructed temperature anomalies reach their minima without any phase difference. But in the earlier MWP, significant discrepancies exist between the simulation and the reconstruction, which might reflect the degrading quality of the reconstruction data. The range of the simulated anomalies (1.62 K) is comparable with that of reconstructed (2.0 K). Diagnosis of the model results indicates that, during the last millennium, variations in solar radiation and volcanic activity are the main controlling factors on regional temperature change, while in the recent 100 years, the change of the concentration of greenhouse gases plays most important role in explaining the rapid temperature rising. [ABSTRACT FROM AUTHOR]

Based on multi-proxy analysis of pollen, carbonate, TOC, TN and δ 13C of organic matters, a high-resolution climatic evolution of Qinghai Lake since the Late Glacial Age is reconstructed. The results indicate that the boundary between the Last Glacial Maximum and the Late Glacial Age is at about 18.2 cal.ka BP. The warm and wet period, which began at about 15.4 cal.ka BP, culminated at 7.4 cal.ka BP and came to its end at about 4.5 cal.ka BP. After that, the climate gradually became cold and dry. The multi-proxy analysis indicates that the climate fluctuated greatly during the transitional period from the Late glacial Age to the Holocene, and this is in good accordance with that reflected by deep sea cores of North Atlantic, ice cores of Greenland, lake sediments in Europe, loess sequences and Guliya ice core in China. The climatic evolutional characteristic of the Qinghai Lake since the Late Glacial Age shows that the driving force of the East-Asia Monsoon correlates with solar radiation on the ten-thousand-year scale. [ABSTRACT FROM AUTHOR]

Dating lake sediment using sedimentary event is the supplement and calibration to traditional dating by radionuclide such as 210Pb and 137Cs. Based on the change of spheroidal carbonaceous particle (SCP) concentration, the age sequence of lake sediments can be deduced. It is one of the dating methods using sedimentary event. SCP is formed from combustion of fossil fuel at high temperature up to 1750°C and at a rate of heating of approaching 104 °C/s. It can be dispersed to several hundred kilometers away from its source and deposited with precipitation or dryly deposited, and kept in sediments. Compared with Cs or Pb, there is no evidence for SCP that it decays in lake sediments and is un-removable once stored except by physical disturbance because it is mainly composed of element carbon. Handy method to extract, identify and calculate has been developed. Although fossil fuel has been used early in China, combustion at high temperature started later since emergence of electricity generation. The productivity of SCP is positively related with the generated thermal power, which is reflected as the SCP concentration in lake sediments increases with the increase of generated thermal power. Therefore, reliable sediment markers from the start of the SCP record and the remarkable variation can be used for dating purpose. In China, electricity industry started from the 1950s, and rapid increase of generated power took place since 1978. Based on these time markers, SCP time sequences of lake sediment cores LH and LL-4 from Longgan Lake, the middle reach of the Yangtze River, have been established, which is comparable with the results from 137Cs and 210Pb, and has eliminated the errors of dating using 137Cs and 210Pb. [ABSTRACT FROM AUTHOR]

The evidence of human activities around Erhai Lake catchment was revealed by pollen records from a sediment core in the lake, northwest Yunnan Province. The chronologic sequence based on AMS 14C data made it possible for pollen results to compare with archaeological records and historical documents. The preliminary deforestation started from the selective clearance at about 5500 14C a BP, marked by the loss of vertically distributed montane forest and the expansion of second pine woodland across the catchment. The deforestation resulted in the increase of surface runoff and the enhanced erosion in the catchment. The increased herbs of pasture and crop suggested the primitive agriculture and stockbreedlng in study region. With the limited human activity, as well as the suitable climatic condition, second pine forest expanded quickly, resulting in the weakened soil erosion around the basin. The strong forest clearance inferred from pollen occurred since 2160 14C a BP, paralleling to the first dense immigration of population, when Yeyu County was first set up around west coast of Erhai Lake, documented in historic record. The development of agriculture led to the steady enhancement of soil erosion from farming land, increasing the input of fine materials and nutrients to the lake. Moreover, the serious deforestation by human activity stressed the vulnerability in ecosystem of the landscape. The time of primary anthropologic impact recorded from pollen is earlier than that of the oldest archaeological record by 1500 a (14C year). [ABSTRACT FROM AUTHOR]

A continuous pollen record from the Zoige Basin in the northeastern Qinghai-Tibetan Plateau not only provides information on the vegetation and climate changes during the last two glacial/interglacial cycles, but also gives proof to establish the time scale of the upper 60 m of the RM core. Subalpine spruce-fir forests colonized the Zoige Basin during the interglacials and interstadials, implying warm and wet climate conditions. Alpine periglacial desert or dry desert may have existed during the penultimate glacial and the last glacial maxima, respectively. Alpine sedge meadow dominated the landscape during MIS 4. The MIS 3 is punctuated by a number of stadials similar to those documented in the Guliya and GISP2 ice cores, as indicated by repeated rise and fall of subalpine spruce-fir forests. Our pollen record reveals a regional climate history similar to those from the neighboring sites, including the Arabian Sea and the Guliya ice core, and thus supports the notion that the Qinghai-Tibetan Plateau acts as an important link between climatic events in the North Atlantic realm and the Asian monsoon domain. [ABSTRACT FROM AUTHOR]

According to high-resolution analyses on multi-proxy of sediment core from the Er-hai Lake, Yunnan Province, the sequence of climatic and environmental change since the Holocene has been reconstructed based on accurate dating. The results show that climate had transited from cold-wet to warm-wet during ca. 12950-8399 aBP in this area, and the transition happened in ca. 10329 aBP. Due to the enhancing southwest Asian monsoon and increasing precipitation, the lake-level of the Erhai Lake began to rise after ca. 10329 a BP. Climate in the catchment was warm and wet during the mid-Holocene, and the warmest stage appeared in ca. 8399-6371 a BP. The lake-level descended in the mid-Holocene because of the decrease of effective moisture in the basin. Human activities appeared in ca. 6371 a BP, and the initial manner mainly focused on deforestation. Up to ca. 2139 a BP, due to the amount of immigration into this area, the cultivation was developed widely, which was followed by mining (coal mine). [ABSTRACT FROM AUTHOR]

The characteristics of climatic environment in the early Holocene epoch were studied through analyzing environmental proxies from the sediments in the Ebinur Lake-a closed one in the arid region. The pollen assemblage and other geochemical indices showed that, the temperature was somewhat low in the period (8.0–11.5 cal kaBP) as a whole, but in the early period (11.5-10.6 cal kaBP) the temperature was higher, in company with more precipitation. In the conversion period from the early Holocene epoch to the middle Holocene epoch (8.9-8.0 cal kaBP) the climate fluctuated remarkably. Particularly the three layers of peat sediment revealed the strong instability of climate in the early Holocene epoch in the Ebinur region. All information on the development of peat and the experimental data of pollen and stable isotopes implied that, the climatic condition at 8.2, 8.6 and 10.5 cal kaBP was characterized by noticeable cold and humidness, and could be regarded as three cold and humid events in the early Holocene epoch. [ABSTRACT FROM AUTHOR]

Based on a multi-proxy investigation into the deep core of the Cuoe Lake in the middle of Tibetan Plateau, a 2.8 Ma paleoclimatic and paleoenvironmental evolution is reconstructed. The result of magnetic stratum indicates that the lake basin was formed at about 2.8 MaBP, while the multi-proxy analyses of lithology, grain size, magnetic susceptibility and geochemical elements reveal that there have been three major environmental evolution stages and at least two intensive uplifts of the Tibetan Plateau in the lake basin area, i.e. during 2.8-2.5 MaBP, the lake basin came into being as a result of the disaggregation of the planation surface and rapid rising of the Tibetan Plateau. During 2.5-0.8 MaBP, with gradual uplift of the Tibetan Plateau, the environment of this area was more effectively controlled by the climatic cycle of the alternative glacial-interglacial stages. After 0.8 MaBP, the middle part of the Plateau accelerated its uplift and entered cryoshere. [ABSTRACT FROM AUTHOR]

Simulated research of internal loading and collecting and analyzing the samples from the lakes were carried out before and after dredging in polluted suburb lakes, Wuli Lake (Wuxi City) and Xuanwu Lake (Nanjing City). The research results showed that dredging can inhibit internal loadings in a certain degree in a short term. The discrepancy of dredging effect and technical level, namely dredging quality, by different dredging methods will result in a difference of control of lake internal loadings. The internal loadings' reversion will gradually appear along with the biogeochemical processes, including suspended particle precipitation, hydrodynamic disturbance and microbio-transformation. The reversion rate mainly depends on the dredging method and the change of interracial processes on the newborn surface layer. The higher nutrient contents and organic matter in the sediment will enhance water-sediment interfacial processes and nutrients regeneration. It is very important to study the physicochemical and biological character of lacustrine sediments before dredging for determining the dredging methods and predicting their environmental effect. [ABSTRACT FROM AUTHOR]

This paper presents the stable isotopic compositions from the cave dripwater and actively forming soda straw stalactites collected from Wanxiang Cave, Wudu, Gansu, located on the Qinghai-Tibetan Plateau and Loess Plateau transition zone, China. The δ18Odw and δDdw of dripwater samples in the cave plot directly on the local MWL, constructed by using GNIP data from 3 sites surrounding the cave regions (Lanzhou, Xi'an, and Chengdu), the nearest site to the cave, suggesting that there is a close relationship between the δ18Odw of the cave water and the δ18Omc of the precipitations. Using the measured δ18Odw and δ18Omc values from the mid-farthest parts from the cave entrance and the carbonate paleotemperature equation, the calculated temperatures range from 8.9 to 12.4°C, with the mean value of 10.7°C and the temperature calculated at 8 locations in the farthest part of the cave is in the range of 10.1–12.4°C, with the mean value of 11.5°C, being consistent with the survey value(10.99°C)in the cave, slightly lower than the mean annual temperature (14.4°C) in Wudu. This suggests that modern speleothems are forming under isotopic equilibrium and their isotopic composition accurately reflects the mean annual temperature at the surface, indicating that the isotopic composition of the modern speleothems records local temperature change with credibility. [ABSTRACT FROM AUTHOR]