Probing Primordial Gravitational Waves: Ali CMB Polarization Telescope

In this paper, we will give a general introduction to the project of Ali CMB Polarization Telescope (AliCPT), which is a Sino-US joint project led by the Institute of High Energy Physics (IHEP) and has involved many different institutes in China. It is the first ground-based Cosmic Microwave Background (CMB) polarization experiment in China and an integral part of China's Gravitational Waves Program. The main scientific goal of AliCPT project is to probe the primordial gravitational waves (PGWs) originated from the very early Universe. The AliCPT project includes two stages. The first stage referred to as AliCPT-1, is to build a telescope in the Ali region of Tibet with an altitude of 5,250 meters. Once completed, it will be the worldwide highest ground-based CMB observatory and open a new window for probing PGWs in northern hemisphere. AliCPT-1 telescope is designed to have about 7,000 TES detectors at 90GHz and 150GHz. The second stage is to have a more sensitive telescope (AliCPT-2) with the number of detectors more than 20,000. Our simulations show that AliCPT will improve the current constraint on the tensor-to-scalar ratio $r$ by one order of magnitude with 3 years' observation. Besides the PGWs, the AliCPT will also enable a precise measurement on the CMB rotation angle and provide a precise test on the CPT symmetry. We show 3 years' observation will improve the current limit by two order of magnitude.Comment: 11 pages, 7 figures, 2 table

Functions of long non-coding RNAs in human disease and their conservation in Drosophila development

Genomic analysis has found that the transcriptome in both humans and Drosophila melanogaster features large numbers of long non-coding RNA transcripts (lncRNAs). This recently discovered class of RNAs regulates gene expression in diverse ways and has been involved in a large variety of important biological functions. Importantly, an increasing number of lncRNAs have also been associated with a range of human diseases, including cancer. Comparative analyses of their functions among these organisms suggest that some of their modes of action appear to be conserved. This highlights the importance of model organisms such as Drosophila, which shares many gene regulatory networks with humans, in understanding lncRNA function and its possible impact in human health. This review discusses some known functions and mechanisms of action of lncRNAs and their implication in human diseases, together with their functional conservation and relevance in Drosophila development

Graphene-Based Nanocomposites for Energy Storage

Since the first report of using micromechanical cleavage method to produce graphene sheets in 2004, graphene/graphene-based nanocomposites have attracted wide attention both for fundamental aspects as well as applications in advanced energy storage and conversion systems. In comparison to other materials, graphene-based nanostructured materials have unique 2D structure, high electronic mobility, exceptional electronic and thermal conductivities, excellent optical transmittance, good mechanical strength, and ultrahigh surface area. Therefore, they are considered as attractive materials for hydrogen (H2) storage and high-performance electrochemical energy storage devices, such as supercapacitors, rechargeable lithium (Li)-ion batteries, Li–sulfur batteries, Li–air batteries, sodium (Na)-ion batteries, Na–air batteries, zinc (Zn)–air batteries, and vanadium redox flow batteries (VRFB), etc., as they can improve the efficiency, capacity, gravimetric energy/power densities, and cycle life of these energy storage devices. In this article, recent progress reported on the synthesis and fabrication of graphene nanocomposite materials for applications in these aforementioned various energy storage systems is reviewed. Importantly, the prospects and future challenges in both scalable manufacturing and more energy storage-related applications are discussed

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements

The mechanisms behind reduced NH4 (+) and NO3 (-) accumulation due to litter decomposition in the acidic soil of subtropical forest

International audienceTo date, very few studies have investigated the effects of litter decomposition on gross nitrogen (N) transformations and N retention in subtropical forest soils. In this study, six forest soils were taken from two contrasting forest types (broad-leaved vs. coniferous) in the humid subtropical zones of China to investigate the effects of litter decomposition on gross N transformations. A (15) N tracing experiment was conducted to investigate the effects of litter decomposition (at a rate of 0.5 % w/w) on soil gross N transformations rates in broad-leaved and coniferous forests. Litter decomposition enhanced gross N mineralization and NH4 (+) immobilization rates by 45.9-79.0 % and 553-563 %, respectively. There was a shift from net N mineralization to net N immobilization in each of the forest soils, which was due to litter decomposition. In contrast, gross nitrification rates were unaffected by litter decomposition for each of the forest soils, while gross NO3 (-) immobilization rates were stimulated significantly by litter decomposition in broad-leaved forest soils but not in coniferous forest soils. On average, 39.4 % of the total NO3 (-) produced was immobilized into organic-N in broad-leaved forest soils due to litter decomposition. Therefore, the decrease in net nitrification rates caused by litter decomposition was attributed to increasing gross NO3 (-) immobilization rates rather than decreasing gross nitrification rates. During 15 days of incubation, the decomposition of litter increased cumulative N2O emissions by 55-76 % and 100-640 % in broad-leaved forest and coniferous forest soils, respectively, but there was no effect on the cumulative NO emissions for both forest soil types. The combined results suggest that the decomposition of litter stimulates N2O emissions but reduces NH4 (+) and NO3 (-) accumulation in forest soils, and thus a delay in N availability for plant N uptake or leaching

Land-use type and temperature affect gross nitrogen transformation rates in Chinese and Canadian soils

International audienceLand-use type affects gross nitrogen transformation and this information is particularly lacking under varied low temperature conditions. In this study, the effects of land-use type (forest vs. grassland) and temperature (10 vs. 15 degrees C) on gross N transformation rates under aerobic conditions were investigated using the (15)N isotope pool dilution technique in the laboratory. Soils were collected from forest and grassland sites in China and Canada. The results showed that gross N mineralization and immobilization rates were significantly higher in forest soils than in grassland soils, while the reverse was true for gross nitrification rates. The higher TC and lower SOCw concentrations in the Chinese soils relative to the Canadian soils were related to the greater gross N mineralization rates and lower gross N immobilization rates in Chinese soils. The greater gross N mineralization rates and lower gross N immobilization rates resulted in much higher inorganic N accumulation and that may increase the risk of NO(3)(-) leaching in the Chinese soils. Increasing temperature significantly increased gross nitrification rates in grassland soils and gross N immobilization rates in forest soils, suggesting that grassland soils maybe more vulnerable to N loss through NO(3)(-) leaching or denitrification (when conditions for denitrification exist) and that conversion of grassland to forest soils may exert less negative effects on the environment by promoting the retention of N and decreasing the production of NO(3)(-) and subsequently the risk of NO(3)(-) leaching under increasing temperature by global warming

Soil pH has contrasting effects on gross and net nitrogen mineralizations in adjacent forest and grassland soils in central Alberta, Canada

International audienceSoil pH can be affected by land use change and acid deposition and is one of the primary regulators of nutrient cycling in the soil. In this study, two soils from adjacent forest and grassland sites in central Alberta were subjected to different pH treatments to evaluate the short-term effects of pH on soil gross N transformations using the N-15 tracing technique and calculated by the numerical model FLUAZ. For the forest soil, gross NH4+ immobilization increased faster than gross N mineralization rates with increasing soil pH, leading to a declining pattern in net N mineralization rates; however, none of those rates changed with pH in the grassland soil. In contrast, the increase in pH significantly stimulated gross and net nitrification rates while soil acidification decreased gross and net nitrification rates for both the forest and grassland soils. The ratio of gross nitrification to gross NH4+ immobilization rates (N/IA) was significantly increased by KOH addition but declined to nearly zero by HCl addition for each soil. The low and high KCI addition treatments partially or completely inhibited gross nitrification rates, respectively, but gross mineralization was less sensitive to salt additions than the nitrification process. We conclude that based on the short-term laboratory incubation experiments both pH and salt (osmotic effect) affected gross N transformations and pH had contrasting effects on gross and net nitrogen mineralization but not on nitrification in the adjacent forest and grassland soils. (C) 2012 Elsevier Ltd. All rights reserved

Atmospheric Nitrogen Deposition Associated with the Eutrophication of Taihu Lake

Environmental effects of excessive amounts of atmospheric nitrogen (N) deposition have raised a great deal of attention. In the present study, the characteristics of N deposition and its contribution to water eutrophication were investigated in the Taihu Basin. The results showed that the annual average total deposition (TN), total wet deposition (TNW), and total dry deposition (TND) rates were 6154, 1142, and 5012 kg·km−2, respectively. Moreover, seasonal fluctuations in TN, TNW, and TND deposition were observed, with a higher N deposition rate occurring in spring and summer. Spatially, the distribution of TN and TND deposition throughout the Taihu Basin was similar. However, the TN deposition rate declined gradually from the southeast to the northwest, while the TNW deposition rate increased. A significant positive correlation was also found between the TN deposition contents with rainfall R=0.803,P=0.01, rainfall frequency R=0.767,P<0.01, and rainfall intensity R=0.659,P<0.05. The TN deposition concentration was significantly negatively correlated with rainfall R=−0.999,P<0.01, rain frequency R=−0.805,P<0.01, and rainfall intensity R=−0.783,P<0.01. The riverine input of TN was estimated to be 112,500 t·N·a−1, and the main N pollutants originated from domestic sewage (accounting for 48.88%) and agriculture (accounting for 28.17%). Livestock and aquaculture contributed 90% of the agricultural pollutants. Additionally, TN deposition contributed 14,400 t N·a−1 to the lake, which accounted for 12.36% of the annual riverine TN inputs. The TN deposition load already exceeds the eutrophication critical load in theory. Furthermore, the contribution of N deposition to the lake has been increasing in recent years, which may accelerate eutrophication of Taihu Lake

SLC26A4 correlates with homologous recombination deficiency and patient prognosis in prostate cancer

Abstract Background Homologous recombination deficiency (HRD) is closely associated with patient prognosis and treatment options in prostate cancer (PCa). However, there is a lack of quantitative indicators related to HRD to predict the prognosis of PCa accurately. Methods We screened HRD-related genes based on the HRD scores and constructed an HRD cluster system to explore different clinicopathological, genomic, and immunogenomic patterns among the clusters. A risk signature, HRDscore, was established and evaluated by multivariate Cox regression analysis. We noticed that SLC26A4, a model gene, demonstrated unique potential to predict prognosis and HRD in PCa. Multi-omics analysis was conducted to explore its role in PCa, and the results were validated by qRT-PCR and immunohistochemistry. Results Three HRD clusters were identified with significant differences in patient prognosis, clinicopathological characteristics, biological pathways, immune infiltration characteristics, and regulation of immunomodulators. Further analyses revealed that the constructed HRDscore system was an independent prognostic factor of PCa patients with good stability. Finally, we identified a single gene, SLC26A4, which significantly correlated with prognosis in three independent cohorts. Importantly, SLC26A4 was confirmed to distinguish PCa (AUC for mRNA 0.845; AUC for immunohistochemistry score 0.769) and HRD (AUC for mRNA 0.911; AUC for immunohistochemistry score 0.689) at both RNA and protein levels in our cohort. Conclusion This study introduces HRDscore to quantify the HRD pattern of individual PCa patients. Meanwhile, SLC26A4 is a novel biomarker and can reasonably predict the prognosis and HRD in PCa