Harnessing high-dimensional hyperentanglement through a biphoton frequency comb

Quantum entanglement is a fundamental resource for secure information processing and communications, where hyperentanglement or high-dimensional entanglement has been separately proposed towards high data capacity and error resilience. The continuous-variable nature of the energy-time entanglement makes it an ideal candidate for efficient high-dimensional coding with minimal limitations. Here we demonstrate the first simultaneous high-dimensional hyperentanglement using a biphoton frequency comb to harness the full potential in both energy and time domain. The long-postulated Hong-Ou-Mandel quantum revival is exhibited, with up to 19 time-bins, 96.5% visibilities. We further witness the high-dimensional energy-time entanglement through Franson revivals, which is observed periodically at integer time-bins, with 97.8% visibility. This qudit state is observed to simultaneously violate the generalized Bell inequality by up to 10.95 deviations while observing recurrent Clauser-Horne-Shimony-Holt S-parameters up to 2.76. Our biphoton frequency comb provides a platform in photon-efficient quantum communications towards the ultimate channel capacity through energy-time-polarization high-dimensional encoding

Near-infrared Hong-Ou-Mandel interference on a silicon quantum photonic circuit

Near-infrared Hong-Ou-Mandel quantum interference is observed in silicon nanophotonic directional couplers with raw visibilities on-chip at 90.5%. Spectrally-bright 1557-nm two-photon states are generated in a periodically-poled KTiOPO4 waveguide chip, serving as the entangled photon source and pumped with a self-injection locked laser, for the photon statistical measurements. Efficient four-port coupling in the communications C-band and in the high-index-contrast silicon photonics platform is demonstrated, with matching theoretical predictions of the quantum interference visibility. Constituents for the residual quantum visibility imperfection are examined, supported with theoretical analysis of the sequentially-triggered multipair biphoton contribution and techniques for visibility compensation, towards scalable high-bitrate quantum information processing and communications.Comment: 15 pages, 6 figure

Query-dominant User Interest Network for Large-Scale Search Ranking

Historical behaviors have shown great effect and potential in various prediction tasks, including recommendation and information retrieval. The overall historical behaviors are various but noisy while search behaviors are always sparse. Most existing approaches in personalized search ranking adopt the sparse search behaviors to learn representation with bottleneck, which do not sufficiently exploit the crucial long-term interest. In fact, there is no doubt that user long-term interest is various but noisy for instant search, and how to exploit it well still remains an open problem. To tackle this problem, in this work, we propose a novel model named Query-dominant user Interest Network (QIN), including two cascade units to filter the raw user behaviors and reweigh the behavior subsequences. Specifically, we propose a relevance search unit (RSU), which aims to search a subsequence relevant to the query first and then search the sub-subsequences relevant to the target item. These items are then fed into an attention unit called Fused Attention Unit (FAU). It should be able to calculate attention scores from the ID field and attribute field separately, and then adaptively fuse the item embedding and content embedding based on the user engagement of past period. Extensive experiments and ablation studies on real-world datasets demonstrate the superiority of our model over state-of-the-art methods. The QIN now has been successfully deployed on Kuaishou search, an online video search platform, and obtained 7.6% improvement on CTR.Comment: 10 page

Effects of biochar amendment and organic fertilizer on microbial communities in the rhizosphere soil of wheat in Yellow River Delta saline-alkaline soil

The biochar and organic fertilizer amendment have been used as an effective practice to increase soil fertility. Nevertheless, the mechanisms of microbial community response to organic fertilizer and biochar application on saline-alkali soil have not been clarified. This study investigated the effects at different concentrations of organic fertilizer and biochar on the microbial community of wheat rhizosphere soil under field experiment in the Yellow River Delta (China, YRD), using high-throughput sequencing technology. Biochar and organic fertilizer significantly influenced in most soil parameters (p < 0.05), apart from soil moisture content (M), pH, total nitrogen (TN) and soil total phosphorus (TP). Proteobacteria and Actinobacteriota were found in the rhizosphere soil as the main bacterial phyla, and the main fungal phyla were Ascomycota and Mortierellomycota. The soil bacterial and fungal communities under organic fertilizer were distinct from CK. Furthermore, redundancy analysis (RDA) directed that changes in bacterial communities were related to soil properties like pH, available phosphorus (AP), and total organic carbon (TOC), while pH, AP and TP, were crucial contributors in regulating fungal distribution. The correlation between soil parameters and bacteria or fungi varied with the application of biochar and organic fertilizers, and the interaction between the bacteria and fungi in organic fertilizer treatments formed more connections compared with biochar treatments. Our results indicated that biochar was superior to organic fertilizer under the contents set up in this study, and soil parameters increased with biochar and organic fertilizer application rate. The diversity and structure of soil bacteria and fungi differed with the application of biochar and organic fertilizer. The research provides a reference to rational application of organic fertilizer and biochar improvement in saline-alkali soil

The diversity and structure of diazotrophic communities in the rhizosphere of coastal saline plants is mainly affected by soil physicochemical factors but not host plant species

The diversity and community structure of rhizospheric microbes are largely affected by soil physicochemical properties and plant species. In this work, high throughput sequencing and quantitative real-time PCR targeting nifH gene were used to assess the abundance and diversity of diazotrophic community in the coastal saline soils of Yellow River Delta (YRD). We demonstrated that the copy number of nifH gene encoding the Fe protein subunit of the nitrogenase in the nitrogen fixation process was significantly affected by soil physiochemical factors, and the abundance of diazotrophs in the rhizospheric soil samples collected from different locations was positively related with soil physicochemical properties. Soil salinity (P=0.003) and moisture (P=0.003) were significantly co-varied with the OTU-based community composition of diazotrophs. Taxonomic analysis showed that most diazotrophs belonged to the Alphaproteobacteria, Gammaproteobacteria and Deltaproteobacteria. Linear discriminant analysis (LDA) effect size (LEfSe) and canonical correspondence analysis (CCA) showed that diazotrophic community structure significantly varied with soil salinity, moisture, pH and total nitrogen, carbon, sulphur and nitrite (NO2–N) content. Our findings provide direct evidence toward the understanding of different effects of soil physicochemical properties and host plant traits such as halophytes types, life span and cotyledon type, on the community composition of diazotrophic populations in the rhizosphere of plants grown in coastal saline soils

Impact of COVID-19 on global burn care.

Worldwide, different strategies have been chosen to face the COVID-19-patient surge, often affecting access to health care for other patients. This observational study aimed to investigate whether the standard of burn care changed globally during the pandemic, and whether country´s income, geographical location, COVID-19-transmission pattern, and levels of specialization of the burn units affected reallocation of resources and access to burn care. The Burn Care Survey is a questionnaire developed to collect information on the capacity to provide burn care by burn units around the world, before and during the pandemic. The survey was distributed between September and October 2020. McNemar`s test analyzed differences between services provided before and during the pandemic, χ2 or Fisher's exact test differences between groups. Multivariable logistic regression analyzed the independent effect of different factors on keeping the burn units open during the pandemic. The survey was completed by 234 burn units in 43 countries. During the pandemic, presence of burn surgeons did not change (p = 0.06), while that of anesthetists and dedicated nursing staff was reduced (<0.01), and so did the capacity to manage patients in all age groups (p = 0.04). Use of telemedicine was implemented (p < 0.01), collaboration between burn centers was not. Burn units in LMICs and LICs were more likely to be closed, after adjustment for other factors. During the pandemic, most burn units were open, although availability of standard resources diminished worldwide. The use of telemedicine increased, suggesting the implementation of new strategies to manage burns. Low income was independently associated with reduced access to burn care. [Abstract copyright: Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved.

Targeting of the Human Coagulation Factor IX Gene at rDNA Locus of Human Embryonic Stem Cells

BACKGROUND: Genetic modification is a prerequisite to realizing the full potential of human embryonic stem cells (hESCs) in human genetic research and regenerative medicine. Unfortunately, the random integration methods that have been the primary techniques used keep creating problems, and the primary alternative method, gene targeting, has been effective in manipulating mouse embryonic stem cells (mESCs) but poorly in hESCs. METHODOLOGY/PRINCIPAL FINDINGS: Human ribosomal DNA (rDNA) repeats are clustered on the short arm of acrocentric chromosomes. They consist of approximately 400 copies of the 45S pre-RNA (rRNA) gene per haploid. In the present study, we targeted a physiological gene, human coagulation factor IX, into the rDNA locus of hESCs via homologous recombination. The relative gene targeting efficiency (>50%) and homologous recombination frequency (>10(-5)) were more than 10-fold higher than those of loci targeted in previous reports. Meanwhile, the targeted clones retained both a normal karyotype and the main characteristics of ES cells. The transgene was found to be stably and ectopically expressed in targeted hESCs. CONCLUSION/SIGNIFICANCE: This is the first targeting of a human physiological gene at a defined locus on the hESC genome. Our findings indicate that the rDNA locus may serve as an ideal harbor for transgenes in hESCs

The Intracellular Transport and Secretion of Calumenin-1/2 in Living Cells

Calumenin isoforms 1 and 2 (calu-1/2), encoded by the CALU gene, belong to the CREC protein family. Calu-1/2 proteins are secreted into the extracellular space, but the secretory process and regulatory mechanism are largely unknown. Here, using a time-lapse imaging system, we visualized the intracellular transport and secretory process of calu-1/2-EGFP after their translocation into the ER lumen. Interestingly, we observed that an abundance of calu-1/2-EGFP accumulated in cellular processes before being released into the extracellular space, while only part of calu-1/2-EGFP proteins were secreted directly after attaching to the cell periphery. Moreover, we found the secretion of calu-1/2-EGFP required microtubule integrity, and that calu-1/2-EGFP-containing vesicles were transported by the motor proteins Kif5b and cytoplasmic dynein. Finally, we determined the export signal of calu-1/2-EGFP (amino acid positions 20–46) and provided evidence that the asparagine at site 131 was indispensable for calu-1/2-EGFP stabilization. Taken together, we provide a detailed picture of the intracellular transport of calu-1/2-EGFP, which facilitates our understanding of the secretory mechanism of calu-1/2

Silkworm Coatomers and Their Role in Tube Expansion of Posterior Silkgland

Background: Coat protein complex I (COPI) vesicles, coated by seven coatomer subunits, are mainly responsible for Golgito-ER transport. Silkworm posterior silkgland (PSG), a highly differentiated secretory tissue, secretes fibroin for silk production, but many physiological processes in the PSG cells await further investigation. Methodology/Principal Findings: Here, to investigate the role of silkworm COPI, we cloned six silkworm COPI subunits (a,b,b9, d, e, and f-COP), determined their peak expression in day 2 in fifth-instar PSG, and visualized the localization of COPI, as a coat complex, with cis-Golgi. By dsRNA injection into silkworm larvae, we suppressed the expression of a-, b9- and c-COP, and demonstrated that COPI subunits were required for PSG tube expansion. Knockdown of a-COP disrupted the integrity of Golgi apparatus and led to a narrower glandular lumen of the PSG, suggesting that silkworm COPI is essential for PSG tube expansion. Conclusions/Significance: The initial characterization reveals the essential roles of silkworm COPI in PSG. Although silkworm COPI resembles the previously characterized coatomers in other organisms, some surprising findings require further investigation. Therefore, our results suggest the silkworm as a model for studying intracellular transport, and woul

Fracture Performance of a Large-Stone Asphalt Mixture Based on a Monotonic Tensile Overlay Test

A large-stone asphalt mixture (LSAM) is usually used as the base course of asphalt pavement to prevent the generation of cracks. However, there are few studies on the fracture performance and crack resistance of LSAMs. Under the monotonic tensile loading mode, the overlay test (OT) was explored to investigate the influence of different test factors on the cracking resistance and fracture performance. The study results indicated that a change in temperature and aging results in a variation in fractal dimension, the fracture energy of crack growth is higher than that of crack initiation, and fracture energy is increased to a certain extent by decreased temperature, an increased loading rate or increased aging. Finally, a constitutive model is established based on the disturbed state concept (DSC), and the proposed constitutive model is consistent with the test results