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The 4.2 ka event is widely presumed to be a globally widespread aridity event and has been linked to several episodes of societal changes across the globe. Whether this climate event impacted the cultural development in south-central China remains uncertain due to a lack of regional paleorainfall records. We present here stalagmite stable carbon isotope and trace element–based reconstruction of hydroclimatic conditions from south-central China. Our data reveal a sub–millennial scale (~5.6 to 4.3 ka) drying trend in the region followed by a gradual transition to wetter conditions during the 4.2 ka event (4.3–3.9 ka). Together with the existing archaeological evidence, our data suggest that the drier climate before 4.3 ka may have promoted the Shijiahe culture, while the pluvial conditions during the 4.2 ka event may have adversely affected its settlements in low-lying areas. While military conflicts with the Wangwan III culture may have accelerated the collapse of Shijiahe culture, we suggest that the joint effects of climate and the region's topography also played important causal roles in its demise.
To assess the role of dietary creatine on myofiber characteristics and protein synthesis in muscle, we fed grass carp (Ctenopharyngodon idellus, initial body weight: 88.47 ± 1.44 g) creatine-supplemented diets (1.84, 5.91, 8.48, and 15.44 g/kg diet) for 8 weeks. Creatine supplementation did not affect growth performance, but significantly increased creatine contents in muscle and liver. At 8.48 g/kg, creatine decreased the activities of alanine transaminase and aspartate aminotransferase in serum, and improved hardness and chewiness of muscle due to shorter myofiber mean diameter, higher myofiber density and the frequencies of the diameters of class I and III and collagen content, longer sarcomere length, and upregulated mRNA levels of slow myosin heavy chains. Creatine supplementation upregulated the mRNA expressions of myogenic regulatory factors. The 8.48 g/kg creatine-supplemented diet significantly increased the contents of protein, total amino acids (AAs), essential AAs, and free flavor AAs in muscle, the protein levels of insulin-like growth factor I, myogenic differentiation antigen, and peroxisome proliferator-activated receptor-γ coactlvator-1α in muscle, and stimulated the phosphorylation of target of rapamycin (TOR) pathway in muscle. In summary, 8.48 mg/kg creatine improved fish health and skeletal muscle growth, and increased hardness and protein synthesis in muscle of grass carp by affecting myofiber characteristics and the TOR signaling pathway. A second-order regression model revealed that the optimal dietary creatine supplementation of grass carp ranges between 8.48 and 12.04 g/kg.
The present study aimed to explore the association between dietary patterns in abdominal obesity obtained by reduced-rank regression (RRR) with visceral fat index (VFI) as a dependent variable and dyslipidemia in rural adults in Henan, China. A total of 29538 people aged 18–79 were selected from the Henan Rural Cohort Study. RRR analysis was used to identify dietary patterns; logistic regression analysis and restricted cubic spline regression models were applied to analyze the association between dietary patterns in abdominal obesity and dyslipidemia. VFI was used as a mediator to estimate the mediation effect. The dietary pattern in abdominal obesity was characterized by high carbohydrate and red meat intake and low consumption of fresh fruits, vegetables, milk, etc. After full adjustment, the highest quartile of dietary pattern scores was significantly associated with an increased risk of dyslipidemia (OR: 1·33, 95 % CI 1·23–1·44, Ptrend < 0·001), there was a non-linear dose–response relationship between them (Poverall-association < 0·001, Pnon-lin-association = 0·022). The result was similar in dose-response between the dietary pattern scores and VFI. The indirect effect partially mediated by VFI was significant (OR: 1·07, 95 % CI 1·06–1·08). VIF explained approximately 53·3 % of odds of dyslipidemia related to the dietary pattern. Abdominal obesity dietary pattern scores positively affected VFI and dyslipidemia; there was a dose-response in both relationships. Dyslipidemia progression increased with higher abdominal obesity dietary pattern scores. In addition, VFI played a partial mediating role in relationship between abdominal obesity dietary pattern and dyslipidemia.
The Dayao Paleolithic site, located in Inner Mongolia on the eastern margin of China's vast northwestern drylands, was a lithic quarry-workshop utilized by Pleistocene human migrants through the region. Determining the age of this activity has previously yielded controversial results. Our magnetostratigraphic and OSL dating results suggest the two artifact-bearing paleosols are correlated with MIS 5 and 7, respectively. Correlating paleoclimatic data with marine δ18O records leads us to conclude that two sandy gravel layers containing many artifacts in the lower part of the Dayao sequence were formed during MIS 9 and 11, if not earlier. Our results reveal that the earliest human occupation at the Dayao site occurred before ca. 400 ka during a relatively warm and moist interglacial period, similar to several subsequent occupations, documenting the earliest and northernmost archaeological assemblage yet reported in China's arid northwest. We conclude that the northward and southward displacements of the East Asian summer monsoon rain belt during past interglacial-glacial cycles were responsible for the discontinuous human occupation detected at the Dayao site. The penetration of this precipitation regime into dryland ecologies via the Huanghe (Yellow River) Valley effectively created a corridor for hominin migration into China's arid northwest.
Scholars have long debated when the Neolithic began in China. Neolithisation, however, is a process rather than an event. It is more realistic to investigate the timing and nature of the socio-economic trajectory from mobile, microblade-using foragers to sedentary communities during the Palaeolithic–Neolithic transition in northern China. Here, the authors use artefacts from Shuidonggou locality 12 to demonstrate the socio-economic organisation of the site's inhabitants. They identify long-term site occupation by a large group exhibiting high levels of individual mobility. Comparative analyses with contemporaneous data indicate that the early stages of complex social organisation—a fundamental element of Neolithisation—emerged among microblade-using groups.
A multidisciplinary fieldwork and research project was recently begun at the Yangshang site (220–140 ka), a late Early Paleolithic locale in the western Chinese Loess Plateau. 1696 lithic artifacts and 337 faunal remains were recovered during the excavation. Sedimentological and paleoenvironmental investigations indicate the site preserves a relatively long and minimally disturbed archaeological sequence associated with paleoenvironmental changes during MIS 7–6. A detailed techno-typological analysis of Yangshang's lithic assemblages was undertaken to examine the influence of glacial cycles on late Middle Pleistocene hominin technological strategies in the western Chinese Loess Plateau. The results show that while the Yangshang site is dominated by quartz-based core/flake assemblages typical of most Early Paleolithic sites in North China, the lithic assemblages provide evidence that different provisioning systems existed during the penultimate glaciation. We argue that these shifts reflect changes in land use and mobility that were tied to climate change. Our results suggest that theoretically informed statistical analyses of so-called unchanging and crude lithic technology can yield meaningful evidence for behavioral shifts.
Straddles on individual stocks generally earn negative and significant returns. However, average at-the-money straddles from 3 days before an earnings announcement to the announcement date yield a highly significant 3.34% return. The positive returns on straddles indicate that investors underestimate the magnitude of uncertainty around earnings announcements. We find that positive straddle returns are more pronounced for smaller firms and firms with higher volatility, higher kurtosis, more volatile past earnings surprises, and less trading volume/higher transaction costs. This suggests that when firm signals are noisy, and/or when it is costlier to trade, investors underestimate the uncertainty associated with earnings announcements.
The crack initiation and early growth behaviors of a TC4 titanium alloy under high cycle fatigue and very high cycle fatigue were experimentally investigated. The results show that it exhibits the duplex S–N curve characteristics associated with surface and interior failures at a stress ratio of 0.1, while it represents the similar S–N curve characteristics only related to surface failure at a stress ratio of −1. The interior failure is accompanied with the occurrence of facets, granular bright facets (GBFs), and fisheye. Slip-like patterns are observable on the facets easily formed under positive stress ratio. The interior failure process is characterized as (i) occurrence of slip lines on partial α grains under cyclic loading, (ii) initiation and growth of microcracks within some α grains, (iii) coalescence of microcracks and formation of GBF, (iv) stable long crack growth within fisheye, (v) unstable crack growth outside fisheye, and (vi) final momentary fracture.
With increasing output of petroleum coke, the value-added exploitation of petroleum coke has become a tough problem. Preparing porous carbons is a traditional way to the value-added exploitation of petroleum coke. Here, we used a facile and efficient hard-templating strategy to synthesize mesoporous carbon with high surface area from petroleum coke. N2 adsorption analyses show that the BET specific area and pore volume of the carbons can reach up to 864 m2/g and 1.37 cm3/g, respectively. To utilize the abundant mesopores of the carbons, anthraquinone-modified mesoporous carbon was tested as an electrode material for supercapacitor applications. Electrochemical measurements demonstrated that the specific capacitance reached up to 366 F/g at the current density of 1 A/g, indicating a promising prospect of using this carbon in electrochemical energy-storage field. More importantly, the strategy used in this work can be easily modified to prepare other nano-carbon materials from petroleum coke.
Gamma-ray observations for Supernova remnant (SNR)-molecular cloud (MC) association systems play an important role in the research on the acceleration and propagation of cosmic-ray protons. Through the analysis of 5.6 years of Fermi-Large Area Telescope observation data, here we report on the detection of a gamma-ray emission source near the SNR Kesteven 41 with a significance of 24σ in 0.2–300 GeV. The best-fit location of the gamma-ray source is consistent with the MC with which the SNR interacts. Several hypotheses including both leptonic and hadronic scenarios are considered to investigate the origin of these gamma-rays. The gamma-ray emission can be naturally explained by the decay of neutral pions produced via the collision between high energy protons accelerated by the shock of Kesteven 41 and the adjacent MC. The electron energy budget would be too high for the SNR if the gamma-rays were produced via inverse Compton (IC) scattering off the Cosmic Microwave Background (CMB) photons.
Outside surface fluctuations of inertial confinement fusion (ICF) capsule greatly affect the implosion performance. An atomic force microscope (AFM)-based profilometer is developed to precisely characterize the capsule surface with nanometer resolution. With the standard nine surface profiles and the complete coverage data, 1D and 2D power spectra are obtained to quantitatively qualify the capsule. Capsule center fast aligning, orbit traces automatic recording, 3D capsule orientation have been studied to improve the accuracy and efficiency of the profilometer.
Foxtail millet (Setaria italica (L.) P. Beauv.) is a naturally stress-tolerant plant, a major reserve crop and a model for panicoid grasses. The recent completion of the S. italica genome facilitates identification and characterization of WRKY transcription factor family proteins that are important regulators of major plant processes, including growth, development and stress response. The present study identified 103 WRKY transcription factor-encoding genes in the S. italica genome. The genes were named SiWRKY1–SiWRKY103 according to their order on the chromosomes. A comprehensive expression analysis of SiWRKY genes among four different tissues was performed using publicly available RNA sequencing data. Eighty-four SiWRKY genes were more highly expressed in root tissue than in other tissues and nine genes were only expressed in roots. Additionally, real-time quantitative polymerase chain reaction was performed to comprehensively analyse the expression of all SiWRKY genes in response to dehydration. Results indicated that most SiWRKY genes (over 0.8) were up-regulated by drought stress. In conclusion, genome-wide identification and expression profiling of SiWRKY genes provided a set of candidates for cloning and functional analyses in plants’ response to drought stress.
The metamorphic responses of mussel (Mytilus coruscus) larvae to pharmacological agents affecting G proteins and the adenylate cyclase/cyclic AMP (AC/cAMP) pathway were examined in the laboratory. The G protein activators guanosine 5′-[β,γ-imido]triphosphate trisodium salt hydrate and guanosine 5′-[γ-thio]triphosphate tetralithium salt only induced larval metamorphosis in continuous exposure assays, and the G protein inhibitor guanosine 5′-[β-thio]diphosphate trilithium salt did not exhibit inducing activity. The non-specific phosphodiesterase inhibitor theophylline and the cAMP-specific phosphodiesterase IV inhibitor 4-(3-Butoxy-4-methoxybenzyl)imidazolidin-2-one exhibited inducing activity, while the non-specific phosphodiesterase inhibitor 3-Isobutyl-1-methylxanthine only showed inducing activity at 10−4 M in continuous exposure assays. The cyclic nucleotide analogue N6,2′-O-Dibutyryladenosine 3′,5′-cyclic monophosphate sodium salt did not exhibit significant inducing activity. Both the adenylate cyclase activator forskolin and the adenylate cyclase inhibitor nitroimidazole exhibited inducing activity at 10−4 to 10−3 M concentrations in continuous exposure assays. Among these tested agents, the adenylate cyclase inhibitor (±)-miconazole nitrate salt showed the most promising inducing effect. The present results indicate that G protein-coupled receptors and signal transduction by AC/cAMP pathway could mediate metamorphosis of larvae in this species.
Susan Keates and Yaroslav Kuzmin have contributed valuable comments on our assessment of the chronology and technological characteristics of Shuidonggou localities 1 and 2. These comments have demonstrated some discordance in our publications that should be corrected here. Their rationale for abandoning the conclusions altogether is, however, weak at best. Most importantly, there is no reason to return to the chronology for the Initial Upper Palaeolithic (hereafter termed IUP) assemblages at the Shuidonggou site complex (SDG) proposed by Madsen et al. (2001). Keates and Kuzmin's critique focuses on two separate issues: the first is our characterisation of the assemblages from the lower part of SDG 2, and the second is our handling of the dates. We will address these in order.
The erosion–corrosion properties and interface microstructure of a Fe–B alloy that contains 3.5 wt% B in flowing liquid zinc have been investigated by electron backscattered diffraction, x-ray diffraction, and scanning electron microscopy to clarify the flowing effect of liquid zinc on erosion performance using a rotating-disk technique. The Fe–B alloy erodes at a low and steady rate in flowing liquid zinc. Flowing liquid zinc can accelerate the iron and zinc mass transfer to form Fe–Zn compounds and promote the removal of loose FeZn13. Much residual corrosion-resistant Fe2B and some erosion products coexist at the erosion interface because of the chemical and micromechanical effects that are created by flowing liquid zinc. The failure of the Fe2B corrosion-resistant skeleton in flowing liquid zinc occurs because of the loss of supporting matrix and also the formation and spread of microcracks during erosion.
A review of recently published temporal data from Shuidonggou Locality 1 indicates that a 40–43 cal ka date for the inception of Initial Upper Paleolithic (IUP) blade-oriented technologies in East Asia is warranted. Comparison of the dates from Shuidonggou to other Asian IUP dates in Korea, Siberia, and Mongolia supports this assertion, indicating that the initial appearance of the IUP in East Asia generally corresponds in time to the fluorescence of the IUP in eastern Europe and western Asia. This conclusion preliminarily suggests that either a version of the IUP originated independently in East Asia just prior to 40 cal ka, or more likely, that an early, initial diffusion of the IUP into East Asia occurred ∼41 cal ka, a hypothesis consistent with current estimates for the evolution or arrival of modern humans in the region.
Red skin disease seriously limits the production and quality of Panax ginseng (ginseng) in the Changbai Mountains of Northeast China, which is the main origin of ginseng. To cultivate ginseng, the albic and humus horizons of albic luvisols are artificially mixed to produce ginseng bed soils. To clarify the relationship between red skin disease and soil characteristics, red skin disease indices were calculated from six plots located on a ginseng farm. Ginseng roots were analysed for aluminium (Al) content. Soils from the ginseng beds were sampled at three depths for the evaluation of physico-chemical parameters. Al fractionation from the soil solid fraction was analysed using atomic absorption spectrophotometry. Ginseng plants exhibiting larger red skin areas accumulated higher concentrations of Al in the epidermis and in the fibrous roots. Ginseng bed soils in the six plots were acidic with pHH2O values ranging from 4.0 to 5.0. Plots exhibiting higher red skin disease indices also had higher bulk densities, moisture contents and nitrate concentrations. They also contained higher concentrations of exchangeable Al, NaOH-extracted Al and ammonium oxalate-oxalic-extracted Al in the bed soils. The Al saturation and molar ratio of base cations to Al were above 20% and below 10, respectively, in the two plots with the highest disease indices. Compact soils with higher moisture, nitrate concentrations and active Al species may increase the incidence of ginseng red skin disease.
The Shuidonggou site cluster in northern China contains 12 different early prehistoric sequences with great potential to cast light on the transition to Upper Palaeolithic behaviour in East Asia. Here researchers present the latest results from Locality 2, reporting seven occupation levels with hearths, animal bone and diverse industries. Although previously compared with European Upper Palaeolithic sequences, the new work proposes a different trajectory of development. Distinctive macroblade technology arrived in the area, possibly from Mongolia or Siberia, about 41000–34000 years ago. This industry subsequently disappeared, to be replaced by flake technologies.
It is well known that extracellular signal-regulated kinase 8 (ERK8) plays pivotal roles in various mitotic events. But its physiological roles in oocyte meiotic maturation remain unclear. In this study, we found that although no specific ERK8 signal was detected in oocyte at the germinal vesicle stage, ERK8 began to migrate to the periphery of chromosomes shortly after germinal vesicle breakdown. At prometaphase I, metaphase I (MI), anaphase I, telophase I, and metaphase II (MII) stages, ERK8 was stably detected at the spindles. By taxol treatment, we clarified that the ERK8 signal was stained on the spindle fibers as well as microtubule asters in MI and MII oocytes. In fertilized eggs, the ERK8 signal was not observed in the two pronuclei stages. At prometaphase, metaphase, and anaphase of the first mitosis, ERK8 was detected on the mitotic spindle. ERK8 knock down by antibody microinjection and specific siRNA caused abnormal spindles, failed chromosome congression, and decreased first polar body extrusion. Taken together, our results suggest that ERK8 plays an important role in spindle organization during mouse oocyte meiotic maturation and early embryo cleavage.
We investigate the interfacial electronic structures of the heterojunction Fe/pentacene/Fe on Cu(100) substrate, using synchrotron-based photoemission spectroscopy. No chemical reaction is observed at either Fe/pentacene or pentacene/Fe interface. The hole injection barrier was estimated to be about 0.95 eV between pentacene and under the Fe thin film. C K-edge NEXAFS revealed that the long axis of pentacene molecule was almost perpendicular to the surface plane. With increasing Fe thickness deposited on pentacene film, the pentacene's HOMO shifts to higher binding energy whereas the C 1s binding energy showed an interesting unusual behaviour due to the initial band bending gradually suppressed by the increasing core-hole screening effect.