An Experimental Investigation of Enhanced SM-OFDM Over Indoor Rician Multipath Channels

In this Correspondence, we investigate enhanced spatial modulation (ESM) aided orthogonal frequency division multiplexing (OFDM) systems. ESM extends the conventional SM by introducing a series of signal constellations. Existing research shows that ESM displays performance superiority over SM in flat-fading channels. For frequency-selective fading channels, we design a practical implementation of an ESM&SM aided OFDM hybrid system to characterize the bit error rate (BER) performance of ESM and conventional SM with an experimental wireless testbed. From the experimental results, it is found that ESM achieves better BER performance than SM on frequency selective channels, which are consistent with the Monte Carlo simulation results

Large Language Model based Long-tail Query Rewriting in Taobao Search

In the realm of e-commerce search, the significance of semantic matching cannot be overstated, as it directly impacts both user experience and company revenue. Along this line, query rewriting, serving as an important technique to bridge the semantic gaps inherent in the semantic matching process, has attached wide attention from the industry and academia. However, existing query rewriting methods often struggle to effectively optimize long-tail queries and alleviate the phenomenon of "few-recall" caused by semantic gap. In this paper, we present BEQUE, a comprehensive framework that Bridges the sEmantic gap for long-tail QUEries. In detail, BEQUE comprises three stages: multi-instruction supervised fine tuning (SFT), offline feedback, and objective alignment. We first construct a rewriting dataset based on rejection sampling and auxiliary tasks mixing to fine-tune our large language model (LLM) in a supervised fashion. Subsequently, with the well-trained LLM, we employ beam search to generate multiple candidate rewrites, and feed them into Taobao offline system to obtain the partial order. Leveraging the partial order of rewrites, we introduce a contrastive learning method to highlight the distinctions between rewrites, and align the model with the Taobao online objectives. Offline experiments prove the effectiveness of our method in bridging semantic gap. Online A/B tests reveal that our method can significantly boost gross merchandise volume (GMV), number of transaction (#Trans) and unique visitor (UV) for long-tail queries. BEQUE has been deployed on Taobao, one of most popular online shopping platforms in China, since October 2023.Comment: WWW Industry Under Revie

A Hybrid Multi-Domain Index Modulation for Covert Communication

In this letter, a hybrid multi-domain index modulation scheme based on spreading codes domain and beam domain is proposed. In our design, the information bit stream is divided into two parts: one for covert transmission using the index of spreading code and the other using the directional modulation to improve bit error ratio (BER) performance in the desired direction and to prevent eavesdropping. Then, based on joint boundaries and statistical theory, the average error probabilities of legitimate users and eavesdroppers are derived. Moreover, we analyze the average BER and validate through simulation results that the proposed hybrid multi-domain scheme is capable of achieving better BER performance compared to conventional coded wireless communication systems

Regulation of gene expression by FSP27 in white and brown adipose tissue

<p>Abstract</p> <p>Background</p> <p>Brown and white adipose tissues (BAT and WAT) play critical roles in controlling energy homeostasis and in the development of obesity and diabetes. The mouse Fat-Specific protein 27 (FSP27), a member of the cell death-inducing DFF45-like effector (CIDE) family, is expressed in both BAT and WAT and is associated with lipid droplets. Over-expression of FSP27 promotes lipid storage, whereas <it>FSP27 </it>deficient mice have improved insulin sensitivity and are resistant to diet-induced obesity. In addition, <it>FSP27</it>-deficient white adipocytes have reduced lipid storage, smaller lipid droplets, increased mitochondrial activity and a higher expression of several BAT-selective genes. To elucidate the molecular mechanism by which FSP27 controls lipid storage and gene expression in WAT and BAT, we systematically analyzed the gene expression profile of <it>FSP27-</it>deficient WAT by microarray analysis and compared the expression levels of a specific set of genes in WAT and BAT by semi-quantitative real-time PCR analysis.</p> <p>Results</p> <p>BAT-selective genes were significantly up-regulated, whereas WAT-selective genes were down-regulated in the WAT of <it>FSP27-</it>deficient mice. The expression of the BAT-selective genes was also dramatically up-regulated in the WAT of <it>leptin/FSP27 </it>double deficient mice. In addition, the expression levels of genes involved in multiple metabolic pathways, including oxidative phosphorylation, the TCA cycle, fatty acid synthesis and fatty acid oxidation, were increased in the <it>FSP27-</it>deficient WAT. In contrast, the expression levels for genes involved in extracellular matrix remodeling, the classic complement pathway and TGF-β signaling were down-regulated in the <it>FSP27-</it>deficient WAT. Most importantly, the expression levels of regulatory factors that determine BAT identity, such as CEBPα/β, PRDM16 and major components of the cAMP pathway, were markedly up-regulated in the WAT of <it>FSP27-</it>deficient mice. The expression levels of these regulatory factors were also up-regulated in <it>leptin/FSP27 </it>double deficient mice. Interestingly, distinct gene expression profiles were observed in the BAT of <it>FSP27-</it>deficient mice. Taken together, these data suggest that the WAT of <it>FSP27-</it>deficient mice have a gene expression profile similar to that of BAT.</p> <p>Conclusions</p> <p>FSP27 acts as a molecular determinant that controls gene expression for a diversity of metabolic and signaling pathways and, in particular, the expression of regulatory factors, including CEBPα/β, PRDM16 and components of the cAMP signaling pathway, that control the identity of WAT and BAT.</p

Phenotype and genotype analyses of Chinese patients with autosomal dominant mental retardation type 5 caused by SYNGAP1 gene mutations

Background: Autosomal dominant mental retardation type 5 (MRD5), a rare neurodevelopmental disorder (NDD) characterized by intellectual disability (ID), developmental delay (DD), and epilepsy predominantly, is caused by a heterozygous mutation in the SYNGAP1 gene. SYNGAP1 mutations have been rarely reported in the Chinese population. Here, we present an investigation of SYNGAP1 mutations in a clinical cohort with ID and DD in Shandong, a northern province in China, to further explore the genotype and phenotype correlations.Methods: A retrospective study was conducted on 10 children with SYNGAP1 mutations presenting ID, DD, and epilepsy who were diagnosed between January 2014 and May 2022. Clinical data and genetic tests were collected. Treatment and regular follow-ups were carried out to pay close attention to the prognosis of the patients.Results: We described 10 unrelated affected individuals with SYNGAP1 mutations, displaying ID, DD, epilepsy, or seizures. All mutations of SYNGAP1 in the 10 patients were de novo, except patient 3 whose father was unavailable, including five nonsense mutations, two frameshift mutations, two splicing mutations, and one codon deletion. Among these mutations, five were novel and the other five were previously reported. Significantly, all patients with epilepsy were sensitive to anti-seizure drugs, especially sodium valproate. Furthermore, rehabilitation training seemed to exert a more improved effect on motor development than language development for the patients.Conclusion The 10 patients carrying SYNGAP1 mutations were diagnosed as MRD5. Five novel genetic mutations were found, which expanded the mutational spectrum of the SYNGAP1 gene. The identification of these mutations in this study helps explore the relationship between genotypes and phenotypes and contributes to genetic counseling and therapeutic intervention for patients with MRD5

Advances in Strain Improvement for the Production of ε-Poly-L-lysine

ε-Poly-L-lysine (ε-PL) is a novel biopolymer consisting of 25–35 L-lysine residues, which is formed by the dehydration condensation of ε-NH2 and α-COOH. ε-PL possesses many excellent characteristics, such as antimicrobial activity, edibility, water solubility, biodegradability, thermostability and nontoxicity. As a natural and safe food preservative, ε-PL possesses many excellent advantages such as thermal stability, edibility, water solubility, degradability, and broad-spectrum antibacterial activity and has been successfully utilized in Japan, South Korea, the United States, China and other countries. ε-PL is usually produced by fermentation with Streptomyces albulus, and improving ε-PL-producing stains is crucial for enhancing ε-PL production and reducing costs. At present, researchers have obtained microbial strains capable of producing high levels of ε-PL by using physicochemical mutagenesis, ribosome engineering, genome shuffling, genetic engineering and other methods. This review introduces the mechanism of ε-PL biosynthesis and recent progress in strain improvement for the production of ε-PL, and gives an overview of the fermentation process of ε-PL. Finally, this review concludes with an outlook on future research directions. We hope that this review can help promote strain improvement for green biological manufacturing of ε-poly-L-lysine

L2hgdh Deficiency Accumulates l-2-Hydroxyglutarate with Progressive Leukoencephalopathy and Neurodegeneration

l-2-Hydroxyglutarate aciduria (L-2-HGA) is an autosomal recessive neurometabolic disorder caused by a mutation in the l-2-hydroxyglutarate dehydrogenase (L2HGDH) gene. In this study, we generated L2hgdh knockout (KO) mice and observed a robust increase of l-2-hydroxyglutarate (L-2-HG) levels in multiple tissues. The highest levels of L-2-HG were observed in the brain and testis, with a corresponding increase in histone methylation in these tissues. L2hgdh KO mice exhibit white matter abnormalities, extensive gliosis, microglia-mediated neuroinflammation, and an expansion of oligodendrocyte progenitor cells (OPCs). Moreover, L2hgdh deficiency leads to impaired adult hippocampal neurogenesis and late-onset neurodegeneration in mouse brains. Our data provide in vivo evidence that L2hgdh mutation leads to L-2-HG accumulation, leukoencephalopathy, and neurodegeneration in mice, thereby offering new insights into the pathophysiology of L-2-HGA in humans

Responses of Pre-Holed Granite under Coupled Biaxial Loading and Unloading Stress Condition

Underground excavation is a necessary process for constructing mines, tunnels and depots in granite rock mass. In this study, the numerical granite specimens were established by the discrete element method and confirmed by laboratory experiments in order to investigate the peak stress, cracking development and failure properties of pre-holed granite under coupled biaxial loading and unloading conditions. The results show that, for the specimens containing D-type and square holes, the peak biaxial unloading strengths first decrease, then increase and finally decrease as the inclination angles of the holes increase. For the specimens with elliptical holes, the peak biaxial unloading strengths first decrease and then increase with the increases in the inclination angles of the holes. The biaxial unloading strengths of specimens containing elliptical, circular, D-type and square holes decrease in that order. The cracks initially appear near the crossover points between the X-type shear fracturing plane and the pre-hole in the center and gradually expand along the X-type shear direction, which indicates that the failure of pre-holed granite is primarily shear failure. When the overall length of cracks expanding along the X-type shear direction extends to the size of the pre-hole in the center, the failure of the pre-holed specimen occurs. When the existing pre-hole in the center of the granite specimen extends to connect with the shear slip in the vicinity of the hole, this triggers overall failure

Earth Video Cube: A Geospatial Data Cube for Multisource Earth Observation Video Management and Analysis

Earth observation (EO) videos are undergoing rapid expansion due to the swift advancements in aerial, spaceborne, and ground remote sensing technologies enabling the continuous capture of imagery of the Earth&#x0027;s surface. Compared with traditional image-based EO data, EO videos offer persistent EO, rendering a promising observation resource across diverse applications, including climate monitoring and hazard assessment. The continuous observation capability introduces a challenge to the community, i.e., how to effectively manage and fully harness the value of the substantial volume of EO videos. In this article, we propose a novel approach leveraging a spatiotemporal data cube with EO video management to facilitate analysis. It suggests an analysis ready data (ARD) for EO videos, termed as analysis ready video data, which is incorporated into an Earth video cube. The ARD includes semantics at frame, object/trajectory, and event levels. This article presents the cube data organization and query processing for EO videos. A prototype system is implemented to demonstrate the applicability of the approach