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We investigate the molecular environment of the supernova remnant (SNR) Kesteven 67 (G18.8+0.3) using observations in $^{12}$CO, $^{13}$CO, HCO$^+$,and HCN lines and possible associated $\gamma$-ray emission using 16-yr Fermi-LAT observation. We find that the SNR is closely surrounded by a molecular belt in the southeastern boundary, with the both recessed in the band-like molecular gas structure along the Galactic plane. The asymmetric molecular line profiles are widely present in the surrounding gas around local-standard-of-rest velocity +20 km s$^{-1}$. The secondary components centered at $\sim$+16km s$^{-1}$ in the belt and $\sim$+26 km s$^{-1}$ in the northern clump can be ascribed to the motion of a wind-blown molecular shell. This explanation is supported by the position-velocity diagram along a line cutting across the remnant, which shows an arc-like pattern, suggesting an expanding gas structure. With the simulation of chemical effects of shock propagation, the abundance ratios $N$(HCO$^+$)/$N$($^{12}$CO) $\sim2.6\times 10^{-5}$--$3.6\times 10^{-4}$ obtained in the belt can be more naturally interpreted by the wind-driven bubble shock than by the SNR shock. The belt and northern clump are very likely to be parts of an incomplete molecular shell of bubble driven by O-type progenitor star's wind. The analysis of 0.2--500 GeV $\gamma$-ray emission uncovers a possible point source (`Source~A') about 6.5$\sigma$ located in the north of the SNR, which essentially corresponds to northern molecular clump. Our spectral fit of the emission indicates that a hadronic origin is favored by the measured Galactic number ratio between CR electrons and protons $\sim0.01$., Comment: 14 pages, 10 figures, accepted by MNRAS

Edge artificial intelligence (AI) and space-ground integrated networks (SGIN) are two main usage scenarios of the sixth-generation (6G) mobile networks. Edge AI supports pervasive low-latency AI services to users, whereas SGIN provide digital services to spatial, aerial, maritime and ground users. This article advocates the integration of the two technologies by extending edge AI to space, thereby delivering AI services to every corner of the planet. Beyond a simple combination, our novel framework, called Space-ground Fluid AI, leverages the predictive mobility of satellites to facilitate fluid horizontal and vertical task/model migration in the networks. This ensures non-disruptive AI service provisioning in spite of the high mobility of satellite servers. The aim of the article is to introduce the (Space-ground) Fluid AI technology. First, we outline the network architecture and unique characteristics of Fluid AI. Then, we delve into three key components of Fluid AI, i.e., fluid learning, fluid inference, and fluid model downloading. They share the common feature of coping with satellite mobility via inter-satellite and space-ground cooperation to support AI services. Finally, we present some experimental case studies to demonstrate the effectiveness of Fluid AI and identify further research opportunities., Comment: 5 pages, 4 figures

Sex chromosomes have independently evolved in species with separate sexes in most lineages across the tree of life. However, the well-accepted canonical model of sex chromosome evolution is not universally supported. There is no single trajectory for sex chromosome formation and evolution across the tree of life, suggesting the underlying mechanisms and evolutionary forces are diverse and lineage specific. We review the diversity of sex chromosome systems, describe the canonical model of sex chromosome evolution, and summarize studies challenging various aspects of this model. They include evidence that many lineages experience frequent sex chromosome turnovers or maintain homomorphic sex chromosomes over long periods of time, suggesting sex chromosome degeneration is not inevitable. Sometimes the sex-limited Y/W chromosomes expand before they contract in size. Both transposable elements and gene gains could contribute to this size expansion, which further challenges gene loss being the hallmark of sex chromosome degeneration. Finally, empirical support for the role of sexually antagonistic selection as a driver of recombination suppression on sex chromosomes remains elusive. We summarize models that result in loss of recombination without invoking sexually antagonistic selection, which have not been empirically verified yet, and suggest future avenues for sex chromosome research., Comment: This has been accepted as a Book chapter for Encyclopedia of Evolutionary Biology book 2nd Edition

Dmrt1 is pivotal in testis formation and function by interacting with genes crucial for Sertoli cell differentiation, such as Sox9. It represses female-determining pathways and ovarian formation by silencing Foxl2. Across 127 vertebrate species, Dmrt1 exhibits sexually dimorphic expression, prior to and during gonadal sex differentiation and in adult testes, implicating its role in master regulation of sex determination and gonadal sex differentiation. Dmrt1 emerges as a master sex-determining gene in one fish, frog, chicken and reptile. Recent studies suggest epigenetic regulation of Dmrt1 in its promoter methylation and transposable element insertion introducing epigenetic modification to cis-regulatory elements, alongside non-coding RNA involvement, in a wide spectrum of sex-determining mechanisms. Additionally, alternative splicing of Dmrt1 was found in all vertebrate groups except amphibians. Dmrt1 has evolved many lineage-specific isoforms (ranging from 2 to 10) but has no sex-specific splicing variants in any taxa, which is in sharp contrast to the constitutional sex-specific splicing of Dsx in insects. Future research should focus on understanding the molecular basis of environmental sex determination from a broader taxon, and the molecular basis of epigenetic regulation. It is also essential to understand why and how multiple alternative splicing variants of Dmrt1 evolve and the specific roles each isoform plays in sex determination and gonadal sex differentiation, as well as the significant differences in the molecular mechanisms and functions of alternative splicing between Dmrt1 in vertebrates and sex-specific splicing of Dsx in insects. Understanding the differences could provide deeper insights into the evolution of sex-determining mechanisms between vertebrates and insects., Comment: 40 pages, 4 figures, 2 tables, 1 supplementary table

Recent advances in large language models (LLMs) have blurred the boundary of high-quality text generation between humans and machines, which is favorable for generative text steganography. While, current advanced steganographic mapping is not suitable for LLMs since most users are restricted to accessing only the black-box API or user interface of the LLMs, thereby lacking access to the training vocabulary and its sampling probabilities. In this paper, we explore a black-box generative text steganographic method based on the user interfaces of large language models, which is called LLM-Stega. The main goal of LLM-Stega is that the secure covert communication between Alice (sender) and Bob (receiver) is conducted by using the user interfaces of LLMs. Specifically, We first construct a keyword set and design a new encrypted steganographic mapping to embed secret messages. Furthermore, to guarantee accurate extraction of secret messages and rich semantics of generated stego texts, an optimization mechanism based on reject sampling is proposed. Comprehensive experiments demonstrate that the proposed LLM-Stega outperforms current state-of-the-art methods., Comment: 9 pages, 4 figures, accepted at ACM Multimedia 2024

We propose Diverse Restormer (DART), a novel image restoration method that effectively integrates information from various sources (long sequences, local and global regions, feature dimensions, and positional dimensions) to address restoration challenges. While Transformer models have demonstrated excellent performance in image restoration due to their self-attention mechanism, they face limitations in complex scenarios. Leveraging recent advancements in Transformers and various attention mechanisms, our method utilizes customized attention mechanisms to enhance overall performance. DART, our novel network architecture, employs windowed attention to mimic the selective focusing mechanism of human eyes. By dynamically adjusting receptive fields, it optimally captures the fundamental features crucial for image resolution reconstruction. Efficiency and performance balance are achieved through the LongIR attention mechanism for long sequence image restoration. Integration of attention mechanisms across feature and positional dimensions further enhances the recovery of fine details. Evaluation across five restoration tasks consistently positions DART at the forefront. Upon acceptance, we commit to providing publicly accessible code and models to ensure reproducibility and facilitate further research., Comment: 12 pages, 10 figures, 12 tables

Red dwarfs have been suggested to be among the possible astrophysical species accelerating particles and emitting TeV $\gamma$-rays. As an effort to search for the GeV $\gamma$-ray counterparts of the suggested TeV emission from eight red dwarfs, we analyse the 0.2--500 GeV $\gamma$-ray emission of the regions covering them exploiting the $\sim$13.6 yr Pass 8 data of the Fermi Large Area Telescope. A GeV $\gamma$-ray emission excess with significance of 3.8$\sigma$ is detected in the direction of the red dwarf V962 Tau. This emission contains V962 Tau in 1$\sigma$ error radius and is independent of the catalog source. However, the stellar flare scenario can hardly explain the total energy and lightcurve derived from the $\gamma$-ray emission in view of the spectral analysis. We also analyse the lightcurves in the positions of the eight red dwarfs and no time bin with significance $>$5$\sigma$ is found. Therefore, no significant emission from the red dwarfs could be concluded to be detected by Fermi-LAT., Comment: 11 pages, 6 figures

We report on our discovery of the radio pulsar, PSR J2016$+$3711, in supernova remnant (SNR) CTB 87, with a $\sim10.8\sigma$ significance of pulses, which confirms the compact nature of the X-ray point source in CTB 87. It is the first pulsar discovered in SNRs using Five-hundred-meter Aperture Spherical radio Telescope (FAST). Its integrated radio pulse profile can be well described by a single component, with a width at 50% of the peak flux density of about 28.1$^\circ$ and an effective width of about 32.2$^\circ$. The mean flux density at 1.25 GHz is estimated to be about 15.5$\mu$Jy. Combined with the non-detection of the radio pulse at lower frequencies, the radio spectral index of the pulsar is constrained to be $\lesssim 2.3$. We also present the timing solution based on 28 follow-up FAST observations. Our results reveal a period of 50.81 ms, period derivative of $7.2\times 10^{-14}$ s s$^{-1}$, and dispersion measure of 428 pc cm$^{-3}$. The strength of the equatorial surface magnetic dipole magnetic field is inferred to be about $1.9\times10^{12}$ G. Using the ephemeris obtained from the radio observations, we searched Fermi-LAT data for gamma-ray pulsations but detected no pulsed signal. We also searched for radio pulses with FAST toward the X-ray counterpart of the gamma-ray binary HESS J1832$-$093 proximate to SNR G22.7$-$00.2 but found no signal., Comment: 7 pages, 5 figures, accepted for publication in MNRAS

Occupying the intermediate-mass regime of the accretion--jet parameter space, radio continuum emission from active galactic nuclei with black hole mass M_BH <~ 10^6 Msun (low-mass AGNs) is a valuable probe to the physics of relativistic jets. Yet the number of low-mass AGNs with radio detection is rather limited so far (~ 40 in total). In this work we make two efforts to search for radio counterparts for the largest sample of optically selected low-mass AGNs. First, we collect counterparts from the recent data releases of SKA pathfinders such as LOFAR Two-metre Sky Survey (LoTSS). Additionally, we deeply mine in Faint Images of the Radio Sky at Twenty-Centimeters (FIRST), fitting the FIRST images of the optical AGNs with an elaborate procedure optimized to detect faint radio sources. We have obtained 151 radio sources (mainly from the SKA pathfinders), including 102 new reliable sources (S/N >= 5) and 23 new candidates (3.5 <= S/N < 5). The majority of these new sources (119 of 125) have flux densities lower than the threshold of the official FIRST catalog. The new sources have rest-frame 20 cm power (P_20cm) from 1.98 x 10^20 to 1.29 x 10^23 W/Hz. For low-z Seyfert galaxies P_20cm correlates with M_BH intrinsically and positively, yet only marginally with Eddington ratio L/L_EDD. In terms of the logN--logS relation for the expanding Universe, the limiting flux density for the completeness of our LoTSS sources turns out to be 0.45 mJy at 1.4 GHz; i.e., complete to such a flux-density level that is four times deeper than the official FIRST catalog., Comment: Full tables uploaded in the arXiv source files. A bonus: useful parameterized formula of the logN--logS relation for the expanding Universe, with an exponent controlling the abruptness degree of the turnover

In this short note, we extend the conservation law of Lamm-Rivi\`ere [Comm. PDEs 2008] for a fourth order elliptic system to supercritical dimensions, under certain Lorentz-Sobolev integrability assumptions on the associated coefficient functions., Comment: 6 Pages

In this short note, we establish a sharp Morrey regularity theory for an even order elliptic system of Rivi\`ere type: \begin{equation*} \Delta^{m}u=\sum_{l=0}^{m-1}\Delta^{l}\left\langle V_{l},du\right\rangle +\sum_{l=0}^{m-2}\Delta^{l}\delta\left(w_{l}du\right)+f\qquad \text{in} B^{2m} \end{equation*} under minimal regularity assumptions on the coefficients functions V^l, w^l and that f belongs to certain Morrey space. This can be regarded as a further extension of the recent L^p-regularity theory obtained by Guo-Xiang-Zheng [15], and generalizes [7, 27] for second and fourth order elliptic systems., Comment: 12 pages