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Variations in glacier meltwater in the source regions of the Tibetan Plateau's (TP) largest lake (Selin Co) and China's longest river (Yangtze River) regulate the local and downstream water balance under the warming climate. However, the magnitude of their variations over the past four decades is still unknown. Here, we examine long-term changes in glacier mass balance over 1976–2017 using KH-9 and CoSSC-TanDEM-X data. We find that the mean rate of glacier mass loss (GML) has accelerated from −0.21 ± 0.11 m a–1 over 1976–2000, to −0.28 ± 0.14 m a–1 over 2000–11, and subsequently to −0.48 ± 0.10 m a–1 over 2011–17. Changes in temperature and precipitation are the major causes of GML. Over 1976–2017, the contribution of decadal GML to Tuotuohe sub-basin runoff ranges from 4.3 to 8.0%, while its contribution to increased lake volume change in Selin Co and Chibzhang Co-Dorsoidong Co ranges from 3.5 to 16.3% and 19.2 to 21.4%, respectively. The GML of source regions made relatively small contributions to river runoff and lake supply, but plays a vital role when precipitation decreases. The quantitative evaluation of the water balance for the sources of great rivers and lakes over the TP is therefore important for water resource management and hydrological cycle studies.
Current evidence suggests that multiple pathways of “early-starting” conduct problems exist, including persisting and declining trajectories. Since relatively little is known about the early onset-declining pathway, this study examined the long-term outcomes of different childhood conduct problem trajectories in a disproportionately high-risk sample (N = 754). Parents reported on children's conduct problems at six time points (kindergarten to grade 7). At age 25, psychosocial outcomes were assessed across five domains (psychopathology, substance use, risky sexual behavior, antisocial behavior, and adaptive outcomes). Four childhood conduct problem trajectories were identified: extremely high increasing (EHI; 3.7%), high stable (HS; 22.0%), moderate decreasing (MD; 38.8%), and low decreasing (LD; 35.5%). The EHI and HS groups displayed the poorest psychosocial functioning at age 25, whereas the LD group exhibited the most positive adjustment. Although individuals in the MD group displayed relatively positive adjustment on some outcomes, they displayed more psychopathology and lower well-being in adulthood than the LD group. These findings suggest that there are diverse pathways of early-starting conduct problems, and that all early starters are at risk for later maladjustment. However, the degree and type of risk is related to the severity of conduct problems throughout childhood.
Early life stress has been associated with emotional dysregulations and altered architecture of limbic-prefrontal brain systems engaged in emotional processing. Serotonin regulates both, developmental and experience-dependent neuroplasticity in these circuits. Central serotonergic biosynthesis rates are regulated by Tryptophan hydroxylase 2 (TPH2) and transgenic animal models suggest that TPH2-gene associated differences in serotonergic signaling mediate the impact of aversive early life experiences on a phenotype characterized by anxious avoidance.
The present study employed an imaging genetics approach that capitalized on individual differences in a TPH2 polymorphism (703G/T; rs4570625) to determine whether differences in serotonergic signaling modulate the effects of early life stress on brain structure and function and punishment sensitivity in humans (n = 252).
Higher maltreatment exposure before the age of 16 was associated with increased gray matter volumes in a circuitry spanning thalamic-limbic-prefrontal regions and decreased intrinsic communication in limbic-prefrontal circuits selectively in TT carriers. In an independent replication sample, associations between higher early life stress and increased frontal volumes in TT carriers were confirmed. On the phenotype level, the genotype moderated the association between higher early life stress exposure and higher punishment sensitivity. In TT carriers, the association between higher early life stress exposure and punishment sensitivity was critically mediated by increased thalamic-limbic-prefrontal volumes.
The present findings suggest that early life stress shapes the neural organization of the limbic-prefrontal circuits in interaction with individual variations in the TPH2 gene to promote a phenotype characterized by facilitated threat avoidance, thus promoting early adaptation to an adverse environment.
Permian–Triassic boundary (PTB) volcanic ash beds are widely distributed in South China and were proposed to have a connection with the PTB mass extinction and the assemblage of Pangea. However, their source and tectonic affinity have been highly debated. We present zircon U–Pb ages, trace-element and Hf isotopic data on three new-found PTB volcanic ash beds in the western Hubei area, South China. Laser ablation inductively coupled plasma mass spectrometry U–Pb dating of zircons yields ages of 252.2 ± 3.6 Ma, 251.6 ± 4.9 Ma and 250.4 ± 2.4 Ma for these three volcanic ash beds. Zircons of age c. 240–270 Ma zircons have negative εHf(t) values (–18.17 to –3.91) and Mesoproterozoic–Palaeoproterozoic two-stage Hf model ages (THf2) (1.33–2.23 Ga). Integrated with other PTB ash beds in South China, zircon trace-element signatures and Hf isotopes indicate that they were likely sourced from intermediate to felsic volcanic centres along the Simao–Indochina convergent continental margin. The Qinling convergent continental margin might be another possible source but needs further investigation. Our data support the model that strong convergent margin volcanism took place around South China during late Permian – Early Triassic time, especially in the Simao–Indochina active continental margin and possibly the Qinling active continental margin. These volcanisms overlap temporally with the PTB biocrisis triggered by the Siberian Large Igneous Province. In addition, our data argue that the South China Craton and the Simao–Indochina block had not been amalgamated with the main body of Pangea by late Permian – Early Triassic time.
Childhood disruptive behaviors are highly prevalent and associated with adverse long-term social and economic outcomes. Trajectories of welfare receipt in early adulthood and the association of childhood behaviors with high welfare receipt trajectories have not been examined.
Boys (n = 1000) from low socioeconomic backgrounds were assessed by kindergarten teachers for inattention, hyperactivity, aggression, opposition, and prosociality, and prospectively followed up for 30 years. We used group-base trajectory modeling to estimate trajectories of welfare receipt from age 19–36 years using government tax return records, then examined the association between teacher-rated behaviors and trajectory group membership using mixed effects multinomial regression models.
Three trajectories of welfare receipt were identified: low (70.8%), declining (19.9%), and chronic (9.3%). The mean annual personal employment earnings (US$) for the three groups at age 35/36 years was $36 500 (s.d. = $24 000), $15 600 (s.d. = $16 275), and $1700 (s.d. = $4800), respectively. Relative to the low welfare receipt group, a unit increase in inattention (mean = 2.64; s.d. = 2.32, range = 0–8) at age 6 was associated with an increased risk of being in the chronic group (relative risk ratio; RRR = 1.16, 95% CI 1.03–1.31) and in the declining group (RRR = 1.13, 95% CI 1.03–1.23), after adjustment for child IQ and family adversity, and independent of other behaviors. Family adversity was more strongly associated with trajectories of welfare receipt than any behavior.
Boys from disadvantaged backgrounds exhibiting high inattention in kindergarten are at elevated risk of chronic welfare receipt during adulthood. Screening and support for inattentive behaviors beginning in kindergarten could have long-term social and economic benefits for individuals and society.
Starch digestion in the small intestines of the dairy cow is low, to a large extent, due to a shortage of syntheses of α-amylase. One strategy to improve the situation is to enhance the synthesis of α-amylase. The mammalian target of rapamycin (mTOR) signalling pathway, which acts as a central regulator of protein synthesis, can be activated by leucine. Our objectives were to investigate the effects of leucine on the mTOR signalling pathway and to define the associations between these signalling activities and the synthesis of pancreatic enzymes using an in vitro model of cultured Holstein dairy calf pancreatic tissue. The pancreatic tissue was incubated in culture medium containing l-leucine for 3 h, and samples were collected hourly, with the control being included but not containing l-leucine. The leucine supplementation increased α-amylase and trypsin activities and the messenger RNA expression of their coding genes (P <0.05), and it enhanced the mTOR synthesis and the phosphorylation of mTOR, ribosomal protein S6 kinase 1 and eukaryotic initiation factor 4E-binding protein 1 (P <0.05). In addition, rapamycin inhibited the mTOR signal pathway factors during leucine treatment. In sum, the leucine regulates α-amylase and trypsin synthesis in dairy calves through the regulation of the mTOR signal pathways.
The present study was undertaken to investigate the antiparasitic activity of extracellular products of Streptomyces albus. Bioactivity-guided isolation of chloroform extracts affording a compound showing potent activity. The structure of the compound was elucidated as salinomycin (SAL) by EI-MS, 1H NMR and 13C NMR. In vitro test showed that SAL has potent anti-parasitic efficacy against theronts of Ichthyophthirius multifiliis with 10 min, 1, 2, 3 and 4 h (effective concentration) EC50 (95% confidence intervals) of 2.12 (2.22–2.02), 1.93 (1.98–1.88), 1.42 (1.47–1.37), 1.35 (1.41–1.31) and 1.11 (1.21–1.01) mg L−1. In vitro antiparasitic assays revealed that SAL could be 100% effective against I. multifiliis encysted tomonts at a concentration of 8.0 mg L−1. In vivo test demonstrated that the number of I. multifiliis trophonts on Erythroculter ilishaeformis treated with SAL was markedly lower than that of control group at 10 days after exposed to theronts (P < 0.05). In the control group, 80% mortality was observed owing to heavy I. multifiliis infection at 10 days. On the other hand, only 30.0% mortality was recorded in the group treated with 8.0 mg L−1 SAL. The median lethal dose (LD50) of SAL for E. ilishaeformis was 32.9 mg L−1.
In this paper, zircon U–Pb geochronology, major and trace elements, and Sr–Nd isotope geochemistry of the Baiyanghe dolerites in northern West Junggar of NW China are presented. The U–Pb dating of zircons from the dolerites yielded ages of 272.2±4 Ma and 276.7±6.2 Ma, which indicate the emplacement times. The dolerites are characterized by minor variations in SiO2 (46.89 to 49.07 wt%), high contents of Al2O3 (13.60 to 13.92 wt%) and total Fe2O3 (11.14 to 11.70 wt%), and low contents of MgO (2.67 to 3.64 wt%) and total alkalis (Na2O+K2O, 5.1 to 5.97 wt%, K2O/Na2O = 0.37–0.94), which indicate affinities to metaluminous tholeiite basalt. The REE pattern ((La/Sm)N = 2.25–2.34, (La/Yb)N = 7.42–8.36), V–Ti/1000 and 50*Zr–Ti/50–Sm discrimination diagrams show that these rocks are OIB-type. The high contents of Zr and Ti indicate a within-plate tectonic setting, and samples plot in the ‘plume source’ field shown on the Dy/Yb(N) versus Ce/Yb(N) diagram. The positive εNd(t) values (+7.09 to +7.48), high initial 87Sr/86Sr ratios (0.70442 to 0.70682) and depletions of Nb and Ta elements in the samples can be explained by the involvement of subducted sediments. In summary, it is possible that the Baiyanghe dolerites were derived from an OIB-like mantle source and associated with a mantle plume tectonic setting. Therefore, our samples provide the youngest evidence for the existence of a mantle plume, which may provide new insights into the Late Palaeozoic tectonic setting of West Junggar.
Si nanoparticles and multi-walled carbon nanotubes (MWNTs) were combined using the simple, inexpensive, and scalable approach involving ultrasonication and positive-pressure filtration to generate binder-free freestanding flexible Si–MWNT (Si–MW) composite paper anodes for Li-ion batteries. Through controlling the Si/carbon nanotube (CNT) weight ratio, the composite with 3:2 Si/CNT ratio exhibited the optimal balance between the high capacity of SiNPs and high conductivity and structural stabilization quality of MWNTs, leading to high rate capability as well as specific capacity and cyclability surpassing the conventional slurry-cast SiNP electrode using binder and current collector and other complicated freestanding Si/carbon composite designs. After 100 cycles, our electrode retained a capacity of 1170 mA h/g at 100 mA/g and 750 mA h/g at 500 mA/g. Moreover, a different electrolyte composition enabled a reversible capacity of 1300 mA h/g at 100 mA/g after 100 cycles. The freestanding feature of our electrodes is promising for enhanced energy density of Li-ion cells.
We report three Palaeozoic sedimentary successions in northeastern South China that display markedly different tectonostratigraphic characteristics: the Jiangshan section exhibits an angular unconformity between the Upper Ordovician and Carboniferous stratra; the Shuangming section exhibits a disconformity between the lower Silurian and Upper Devonian strata; and the Xinqiao section exhibits a disconformity between the upper Silurian and Upper Devonian strata. The Shuangming and Xinqiao sections are interpreted to represent the remnant Nanhua foreland basin, whereas the Jiangshan section is in the fold-and-thrust zone of the Wuyi-Yunkai orogen. The Lizhu-Changshan thrust fault in between is interpreted to be the frontal thrust and the boundary of the orogen. Detrital provenance analysis of the Ordovician–Devonian sandstones from the Shuangming and Xinqiao sections shows that the Ordovician–Silurian, mid- to late-orogenic sandstones contain dominantly 860–780 Ma zircon populations and subordinate 2.5 Ga, 1.89–1.78 Ga, 980–950 Ma, 630–540 Ma and 430 Ma populations, indicating nearby sources including the early Neoproterozoic Sibao orogen, inverted Neoproterozoic rift basins and related plutons, recycled Ediacaran–Cambrian strata and, increasing with time, exposed Cathaysia basement and minor syn- to late-orogenic plutonic intrusions. The Devonian post-orogenic sandstones exhibit a dominant 440 Ma population with minor 2.5 Ga, 1.89–1.78 Ga, 860–780 Ma and 630–540 Ma populations, suggesting a dominant contribution from now widely exposed, mid- to late-orogenic plutonic intrusions (with or without contributions from rare volcanism of similar ages) in a residual topographic high SE of the Lizhu-Changshan fault. This residual topographic high of the Wuyi-Yunkai orogen had completely perished by early Carboniferous time, c. 60Myr after the end of the orogenic event.
We study the instability mechanisms leading to slug flow formation in an inclined pipe subject to gravity forces. We use a phase-field approach, where the Cahn–Hillard model is used to model the interface. At the inlet, a stratified flow is imposed with a specified velocity profile. We validate our numerical results by comparing against previous theoretical models and by predicting the various flow regimes for horizontal and inclined pipes, including stratified flow, slug flow, dispersed bubble flow and annular flow. Subsequently, we focus on slug formation in an inclined pipe and connect its appearance with specific vortical dynamics. A two-dimensional channel geometry is first considered. When the heavy fluid is injected as the top layer, inverted vortex shedding emerges, which periodically impacts on the bottom wall, as it develops further downstream. The accumulation of heavy fluid in the bottom wall causes a back flow that induces rolling waves and interacts with the upstream jet. When the heavy fluid is placed as the bottom layer, the heavy fluid accumulates and initially forms a massive slug at the bottom region, close to the inlet. Subsequently, the heavy fluid slug starts to break into smaller pieces, some of which translate along the pipe. During the accumulation phase, a back flow forms also generating rolling waves. Occasionally, a rolling wave can reach the top of the pipe and form a new slug. To describe the generation of vorticity from the two-phase interface and pipe walls in the slug formation, we study the circulation dynamics and connect it with the resulting two-phase flow patterns. Finally, we conduct three-dimensional (3-D) simulations in a circular pipe and compare the differences between the 3-D flow patterns and its circulation dynamics against the 2-D simulation results.
This cross-sectional study aimed to examine and compare prevalence and correlates of whole blood Epstein–Barr virus (EBV) DNA between HIV-positive and HIV-negative men who have sex with men (MSM). Five hundred and four HIV-positive MSM and 504 age-matched HIV-negative MSM were recruited from an HIV counseling and testing clinic in Shanghai, China from November 2014 to November 2015 and were administered with a face-to-face questionnaire interview. Whole blood EBV DNA was tested by nested polymerase chain reaction assays on EBNA-1, EBNA-2, and LMP-1 genes. The prevalence of whole blood EBV DNA was 56·0% (95% CI 51·7–60·3%) among HIV-positive MSM and 26·0% (95% CI 22·4–30·0%) among HIV-negative MSM. Whole blood EBV DNA positivity was significantly associated with HIV infection (adjusted odds ratio (aOR) 3·43, 95% CI 2·58–4·57) and frequent intake of pickled, smoked, or salty food (aOR 1·71, 95% CI 1·02–2·86) in the whole sample, and with <200 cells/μl CD4 cell counts (aOR 1·79, 95% CI 1·05–3·05) and pickled, smoked, or salty food intake (aOR 3·14, 95% CI 1·39–7·08) in HIV-positive group. HIV-infected MSM are at higher risk of active EBV replication than HIV-uninfected MSM, underscoring needs of surveillance and research on EBV-related carcinogenesis in this population.
This study draws on a case study of Wukan and interviews with migrants and peasants in other sites to examine how migration shapes popular resistance in migrant-sending communities (i.e. rural China). Findings demonstrate multidimensional roles played by migrants and returned migrants who act as a vehicle of informational and ideological transmission and at times directly participate in or even lead rural resistance in origin communities. Both the transmission and participation processes foster political consciousness and action orientations among peasants. The importance of migrants is exemplified in the Wukan protests but is also found in other settings under study. In general, migrants represent a latent political force that acts upon serious grievances back home. The findings provide a useful lens for understanding the diffusion of popular resistance and the linkage between urban and rural activism in China.
We model how a rent-protection motive drives the choice of flotation method in new equity issuance between two polar cases: rights issues and cash offers. Unexpected new blockholders would emerge in control-diluting cash offers and share in jealously guarded control benefits. But rights issues help the incumbent controlling shareholders avoid control dilution and safeguard their private benefits. Under asymmetric information about private benefits, the choice of flotation method can convey information about hidden private benefits and hence firm value. Our model can explain even a negative announcement effect of rights issues, and it supports not just one but three important equilibriums.
Facilitated by recent establishment of terrestrial networks and satellite constellations of Automatic Identification System (AIS) receivers, ship trajectories are becoming increasingly available and the size of recorded trajectories is getting larger. Large sets of trajectories create problems of storing, transmitting and processing data. Using appropriate methods, an accurate representation of the original trajectories can be obtained by compressing redundant information, while maintaining the main characteristic elements. In this paper, a new scheme and the implementation of the Douglas-Peucker (DP) algorithm are presented, which can simplify AIS trajectories by extracting characteristic points. As for the simplification threshold, the solo parameter of the DP algorithm, a new AIS-based minimum ship domain evaluation method is proposed and acts as criteria for simplification threshold determination. Finally, a validation is made to examine the effectiveness of the DP simplification algorithm and the rationality of the simplification threshold. The result indicates that the DP algorithm can simplify AIS trajectories effectively; the simplification threshold is scientific and reasonable.
For any given matrix A ∈ℂnxn, a preconditioner tU(A) called the
superoptimal preconditioner was proposed in 1992 by Tyrtyshnikov. It has been
shown that tU(A) is an efficient preconditioner for
solving various structured systems, for instance, Toeplitz-like systems. In this
paper, we construct the superoptimal preconditioners for different functions of
matrices. Let f be a function of matrices from ℂnxn to ℂnxn. For any A ∈ ℂ nxn, one may construct two superoptimal preconditioners for f(A):
tU(f(A)) and f(tU(A)).
We establish basic properties of tU(f(A)) and
f(tU(A)) for different functions of
matrices. Some numerical tests demonstrate that the proposed preconditioners are
very efficient for solving the system f(A)x = b.
Proton radiography is used for advanced hydrotesting as a new type radiography technology due to its powerful penetration capability and high detection efficiency. A new proton radiography terminal will be developed to radiograph static samples at the Institute of Modern Physics of Chinese Academy of Science. The proton beam with the maximum energy of 2.6 GeV will be produced by Heavy Ion Research Facility in Lanzhou-Cooling Storage Ring. The proton radiography terminal consists of the matching magnetic lens and the Zumbro lens system. In this paper, the design scheme and all optic parameters of this beam terminal for 2.6 GeV proton energy are presented by simulating the beam optics using WINAGILE code. My-BOC code is used to test the particle tracking of proton radiography beam line. Geant4 and G4beamline codes are used for simulating the proton radiography system. The results show that the transmission efficiency of proton without target is 100%, and the effect of secondary particles can be neglected. To test this proton radiography system, the proton images for an aluminum plate sample with two rectangular orifices and a step brass plate sample are respectively simulated using Geant4 code. The results show that the best spatial resolution is about 36 μm, and the differences of the thickness are not >10%.
In this study, the authors have comparatively studied the influence of H2 addition on the structures and properties of ZnO films grown by metal organic (MO) chemical vapor deposition with dimethyl zinc and diethyl zinc as zinc precursors and N2O and O2 as oxygen sources, respectively. Various characterization methods, like x-ray diffraction, Raman scattering, Hall effect, photoluminescence, and atomic force microscopy, have been utilized, showing that H2 has different effects on different MO precursors and oxidants. The H2 addition has significantly improved the crystal structural quality of ZnO thin films for the case of dimethyl zinc source, but an opposite effect has been found for the case of diethyl zinc. Moreover, the H2 addition can significantly improve the optical properties of the ZnO films, regardless of the zinc MO sources used, with the surface morphology improved too. The suppression of carbon-related contaminations depends on the use of different precursors and whether H2 is added. By analyzing the experimental results, we have given the effects of H2 on the decomposition of the discussed MO precursors and oxidants, the proposed mechanism could be used in understanding the experimental data.
The etiology and pathogenesis of neurodegenerative disorders has yet to be elucidated, so their differential diagnosis is a challenge. This is especially true in differentiating Alzheimer's disease (AD), dementia with Lewy bodies (DLB), Parkinson disease (PD), and multiple system atrophy (MSA).
A total of 11 eligible articles were identified by search of electronic databases including PubMed, Springer Link, Elsevier, and the Cochrane Library, up to June 2014. In meta-analyses, standardized mean differences (SMD), with 95% confidence intervals (CI), comparing cerebrospinal fluid (CSF) measures of α-synuclein between the above conditions were calculated using random-effects models.
CSF α-synuclein concentrations were significantly higher in AD compared to DLB [SMD: 0.32, 95% CI: (0.02, 0.62), z = 2.07, P = 0.038]; PD [SMD: 0.87, 95% CI: (0.15, 1.58), z = 2.38, P = 0.017]; or MSA [SMD: 1.14, 95% CI: (0.15, 2.14), z = 2.25, P = 0.025]. However, no significant difference was found between patients with AD and neurological cognitively normal controls [SMD: 0.02, 95% CI: (−0.21, 0.24), z = 0.13, P = 0.894].
Results of these meta-analysis suggest that quantification of CSF α-synuclein could help distinguish AD from other neurodegenerative disorders such as DLB, PD, or MSA.