PAHs in the North Atlantic Ocean and the Arctic Ocean: Spatial Distribution and Water Mass Transport

In the Arctic Ocean, it is still unclear what role oceanic transport plays in the fate of semivolatile organic compounds. The strong-stratified Arctic Ocean undergoes complex inputs and outputs of polycyclic aromatic hydrocarbons (PAHs) from the neighboring oceans and continents. To better understand PAHs’ transport processes and their contribution to high-latitude oceans, surface seawater, and water column, samples were collected from the North Atlantic Ocean and the Arctic Ocean in 2012. The spatial distribution of dissolved PAHs (∑9PAH) in surface seawater showed an “Arctic Shelf \u3e Atlantic Ocean \u3e Arctic Basin” pattern, with a range of 0.3–10.2 ng L−1. Positive matrix factorization modeling results suggested that vehicle emissions and biomass combustion were the major PAHs sources in the surface seawater. According to principal component analysis, PAHs in different water masses showed unique profiles indicating their different origins. Carried by the Norwegian Atlantic Current (0–800 m) and East Greenland Current (0–300 m), PAH individuals’ net transport mass fluxes ranged from −4.4 ± 1.7 to 53 ± 39 tons year−1 to the Arctic Ocean. We suggested the limited contribution of ocean currents on PAHs’ delivery to the Arctic Ocean, but their role in modulating PAHs’ air–sea interactions and other biogeochemical processes needs further studies

A new form of (unexpected) Dirac fermions in the strongly-correlated cerium monopnictides

Discovering Dirac fermions with novel properties has become an important front in condensed matter and materials sciences. Here, we report the observation of unusual Dirac fermion states in a strongly-correlated electron setting, which are uniquely distinct from those of graphene and conventional topological insulators. In strongly-correlated cerium monopnictides, we find two sets of highly anisotropic Dirac fermions that interpenetrate each other with negligible hybridization, and show a peculiar four-fold degeneracy where their Dirac nodes overlap. Despite the lack of protection by crystalline or time-reversal symmetries, this four-fold degeneracy is robust across magnetic phase transitions. Comparison of these experimental findings with our theoretical calculations suggests that the observed surface Dirac fermions arise from bulk band inversions at an odd number of high-symmetry points, which is analogous to the band topology which describes a $\mathbb{Z}_{2}$-topological phase. Our findings open up an unprecedented and long-sought-for platform for exploring novel Dirac fermion physics in a strongly-correlated semimetal

Simulation study of BESIII with stitched CMOS pixel detector using ACTS

Reconstruction of tracks of charged particles with high precision is very crucial for HEP experiments to achieve their physics goals. As the tracking detector of BESIII experiment, the BESIII drift chamber has suffered from aging effects resulting in degraded tracking performance after operation for about 15 years. To preserve and enhance the tracking performance of BESIII, one of the proposals is to add one layer of thin CMOS pixel sensor in cylindrical shape based on the state-of-the-art stitching technology, between the beam pipe and the drift chamber. The improvement of tracking performance of BESIII with such an additional pixel detector compared to that with only the existing drift chamber is studied using the modern common tracking software ACTS, which provides a set of detector-agnostic and highly performant tracking algorithms that have demonstrated promising performance for a few high energy physics and nuclear physics experiments

Epidemiology of Schistosomiasis in the People’s Republic of China, 2004

Although the number of human infections decreased, human prevalence increased from 4.9% in 1995 to 5.1% in 2004

Periodic solutions for Rayleigh type p-Laplacian equation with deviating arguments

AbstractBy using topological degree theory and some analysis skill, we obtain some sufficient conditions for the existence of periodic solutions for Rayleigh type p-Laplacian differential equation with deviating arguments

Manure amendment acts as a recommended fertilization for improving carbon sequestration efficiency in soils of typical drylands of China

It is generally known that soil organic carbon (SOC) stocks tend to increase with an increase in C input, whereas the C sequestration efficiency (CSE), i.e., the conversion ratio of C input to SOC, differs depending on the amount and type of C input. However, there is still a need to better understand the impact of various fertilization practices on CSE. We studied the data from eight long-term experiments located in the main dryland region of China in order to comprehensively assess the key drivers of CSE in the plow layer considering nearly four decades of various fertilizer treatments, i.e., no fertilizer (CK); chemical nitrogen, phosphorus, and potassium (NPK/NP); chemical fertilizers plus manure (NPKM/NPM/NM); and straw (NPKS/NPS/NS). Our results showed that manure amendment had the most significant fertilization effect on SOC sequestration with an average CSE of 14.9%, which was significantly higher than that of chemical fertilization (9.0%) and straw return treatments (7.9%). In addition, manure amendment also had the highest average SOC increase rate of 684 kg C ha-1 yr-1. Variance partitioning analysis (VPA) illustrated that the CSE of the main dryland region of China was mostly controlled by edaphic characteristics (32.2%), especially the soil C/N ratio and clay content. VPA and structural equation modeling revealed that the magnitude and influencing factors driving CSE varied among different fertilizer treatments. Soil total N was the limiting factor for CSE in the CK treatment, whereas the soil C/N ratio and pH were the main explanatory factors for CSE in the long-term chemical NPK fertilizer treatment. The negative impact of C input from straw was the main driver of CSE under straw return treatments, though C input had a positive effect on the improvement of soil physical properties. However, when considering manure amendments, the improvement of soil nutrients and clay content controlled CSE, underlining the main positive direct effect of soil chemical properties. In a nutshell, our results recommend manure plus chemical fertilizers as a sustainable practice for improving the C sequestration rate and efficiency in dryland cropping systems

Effect of tillage and crop residue on soil temperature following planting for a Black soil in Northeast China

Abstract Crop residue return is imperative to maintain soil health and productivity but some farmers resist adopting conservation tillage systems with residue return fearing reduced soil temperature following planting and crop yield. Soil temperatures were measured at 10 cm depth for one month following planting from 2004 to 2007 in a field experiment in Northeast China. Tillage treatments included mouldboard plough (MP), no till (NT), and ridge till (RT) with maize (Zea mays L.) and soybean (Glycine max Merr.) crops. Tillage had significant effects on soil temperature in 10 of 15 weekly periods. Weekly average NT soil temperature was 0–1.5 °C lower than MP, but the difference was significant (P < 0.05) only in 2007 when residue was not returned in MP the previous autumn. RT showed no clear advantage over NT in increasing soil temperature. Higher residue coverage caused lower soil temperature; the effect was greater for maize than soybean residue. Residue type had significant effect on soil temperature in 9 of 15 weekly periods with 0–1.9 °C lower soil temperature under maize than soybean residue. Both tillage and residue had small but inconsistent effect on soil temperature following planting in Northeast China representative of a cool to temperate zone

Development and external validation of a radiomics model for assessment of HER2 positivity in men and women presenting with gastric cancer

Key points Radiomics model holds promise in identifying HER2 positivity in GCs. The conventional CT-based HER2-specific radiomics model might generalize to DECT. This study provides an imaging surrogate for stratifying GC by HER2 expression