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Online social networks attract billions of active users and deeply influence people's lifestyles. However, as public social networks with low requirements for registration and joining, it is inevitable that social bots are able to easily register and do harmful things such as controlling public opinion and spreading inaccurate information for profit. Nevertheless, single-site social bot detection systems often rely on historical behavioral data to identify bots, and the detection occurred after the social bots have implemented their attacks. To identify social bots as early as possible, this paper proposes Cerberus, a cross-site system for detecting social bots in social networks, which solves the cold-start problem of user identification caused by insufficient user data on a single platform at an early stage and thus identifies social bots as early as possible. In this paper, the system is designed to identify whether a user on Twitter is a bot or not by leveraging the user's profile and text contents on his or her Medium account linked to Twitter. The results from our experiments show that the AUC score of the system can reach 0.7522, which outperforms others.

As coal mining is shifted to the deep in Shendong mining area and fluorine concentration in mine water is increasing, it is of great significance to study the main sources of fluoride for the control of fluoride pollution in mine water. In order to further prove that natural fluorine-containing minerals are the main source of fluorine in mine water, it is necessary to deeply understand the leaching process of natural fluorine-containing minerals in mine water.Take the Shendong mining Area as an example, the water quality change law of mine water at different depths was analyzed, the fluoride content change of rock mining areas at different depths was studied, and the fluoride leaching regularity of natural fluorine-containing minerals in mine water was discussed. The results show that the fluoride concentration in the mine water exceeds the standard value of class III fluoride on the surface, and the proportion of fluorine-containing minerals in natural minerals increases,when the coal mining depth is more than 120 m. Through analyzing the anion and cation components of the mine water, it is believed that the fluoride in the mine water mainly comes from the leaching of fluorine-containing minerals in deep coal mining. Further study on the leaching law of fluorine-containing minerals under different water rock interaction conditions shows that the leaching of fluoride in fluorine-containing minerals can be accelerated by increasing the strength of water rock interaction; When the rock water ratio was increased (more than 1∶50), the fluoride leaching concentration of some fluorine-containing minerals was greater than 1.0 mg/L; Especially under acidic or alkaline conditions, the insoluble fluorides in fluorine-containing minerals were dissolved due to ion exchange and leaching equilibrium mechanism.To sum up, the high fluoride (more than 1.0 mg/L) in mine water was caused by fluoride leaching, because fluoride in natural fluorine-containing minerals is dissolved out under certain water rock interaction conditions. It is an important guidance to accurately control the fluoride leaching of natural minerals under complex geological conditions.

Identifying the mechanisms underlying cognitive development in early life is a critical objective. The expression of insulin-like growth factor binding protein 2 (IGFBP2) in the hippocampus increases during neonatal development and is associated with learning and memory, but a causal connection has not been established. Here, it is reported that neurons and astrocytes expressing IGFBP2 are distributed throughout the hippocampus. IGFBP2 enhances excitatory inputs onto CA1 pyramidal neurons, facilitating intrinsic excitability and spike transmission, and regulates plasticity at excitatory synapses in a cell-type specific manner. It facilitates long-term potentiation (LTP) by enhancing N-methyl-d-aspartate (NMDA) receptor-dependent excitatory postsynaptic current (EPSC), and enhances neurite proliferation and elongation. Knockout of igfbp2 reduces the numbers of pyramidal cells and interneurons, impairs LTP and cognitive performance, and reduces tonic excitation of pyramidal neurons that are all rescued by IGFBP2. The results provide insight into the requirement for IGFBP2 in cognition in early life.

Objective To determine the effects of ultrasound stimulated microbubble (USMB) by different ultrasound combinations of pulse length (PL) and pulse repetition frequency (PRF) under fixed mechanical index and duty cycle on tumor perfusion and drug delivery in C57BL/6 mice. Methods Twenty-four female C57BL/6 mice (6~8 weeks old, average body weight 17.74±0.43 g) were randomly divided into 3 groups (n=8): control group (group A), DOX+PL3.0+PRF2000 group (group B) and DOX+PL30.5+PRF200 group (group C) after being carried with MC38 xenograft tumor. Contrast-enhanced ultrasound (CEUS) was performed before and after USMB treatment to compare the peak intensity (PI), area under the curve (AUC) and tumor perfusion percentage. Doxorubicin (DOX) was injected slowly after USMB treatment, and then the concentration of DOX in the tumor was detected with high-performance liquid chromatography (HPLC). Microstructure of the tumor was observed pathologically. Results The values of PI and AUC after treatment had no significant differences when compared with those before treatment in group A (P>0.05), the values were increased by 19.3% and 18.0%, respectively in group B (P0.05), and the area increased by 21.0% in group B (P0.05). The pathological results showed that the tumor microvessels in group A and B were slightly and moderately dilated, while those in group C were ruptured and bleeding. Conclusion Under the fixed mechanical index and duty cycle, USMB with higher PRF and lower PL can enhance tumor blood perfusion and promote drug delivery. However, higher PL and lower PRF can block tumor blood perfusion.

This study aims to explore an autoencoder-based method for generating brain MRI images of patients with Autism Spectrum Disorder (ASD) and non-ASD individuals, and to discriminate ASD based on the generated images. Initially, we introduce the research background of ASD and related work, as well as the application of deep learning in the field of medical imaging. Subsequently, we detail the architecture and training process of the proposed autoencoder model, and present the results of generating MRI images for ASD and non-ASD patients. Following this, we designed an ASD classifier based on the generated images and elucidated its structure and training methods. Finally, through analysis and discussion of experimental results, we validated the effectiveness of the proposed method and explored future research directions and potential clinical applications. This research offers new insights and methodologies for addressing challenges in ASD studies using deep learning technology, potentially contributing to the automated diagnosis and research of ASD. [ABSTRACT FROM AUTHOR]

Postembryonic development of animals has long been considered an internally predetermined program, while macronutrients were believed to be essential solely for providing biomatters and energy to support this process. However, in this study, by using a nematode Caenorhabditis elegans (abbreviated as C. elegans hereafter) model, we surprisingly discovered that dietary supplementation of palmitic acid alone, rather than other abundant essential nutrients such as glucose or amino acid mixture, was sufficient to initiate early postembryonic development even under complete macronutrient deprivation. Such a development was evidenced by changes in morphology, cellular markers in multiple tissues, behaviors, and the global transcription pattern and it occurred earlier than the well-known early L1 nutrient checkpoint. Mechanistically, palmitic acid did not function as a biomatter/energy provider, but rather as a ligand to activate the nuclear hormone receptor NHR-49/80, leading to the production of an unknown peroxisome-derived secretive hormone in the intestine. This hormonal signal was received by chemosensory neurons in the head, regulating the insulin-like neuropeptide secretion and its downstream nuclear receptor to orchestrate global development. Additionally, the nutrient-sensing hub mTORC1 played a negative role in this process. In conclusion, our data indicate that free fatty acids act as a primary nutrient signal to launch the early development in C. elegans, which suggests that specific nutrients, rather than the internal genetic program, serve as the first impetus for postembryonic development. Macronutrients are known to provide biomatter and energy to postembryonic development in animals. This study shows that free fatty acids act as a primary nutrient signal to trigger early development in C. elegans, expanding the traditional function of specific nutrients. [ABSTRACT FROM AUTHOR]

An ultra-sensitive multi-channel fluorescence probe for the detection of Al3+ in aqueous solution, 4-(diethylamino)salicylaldehyde nicotinoyl hydrazone (SBN), was synthesized. Interestingly, when 365 nm and 425 nm are the excitation wavelengths, SBN exhibits high selectivity and ultra-sensitive fluorescence enhancement recognition for Al3+ with emission wavelengths of 459 nm and 512 nm, respectively. At the same time, when 459 nm and 512 nm are utilized as the emission wavelengths, SBN also exhibits high selectivity and ultra-sensitive fluorescence off–on recognition for Al3+. Moreover, the presence of Al3+ can change the color of SNB solution from colorless to yellow, which enables SBN to be used as a highly selective and sensitive colorimetric probe for Al3+. The results of HRMS confirm the formation of a complex between SBN and Al3+ with a 3 : 1 binding ratio. The density functional theory (DFT) calculation indicates that the hydroxyls and the nitrogen atoms on carbon nitrogen double bonds in the three SBN molecules can form three chelating rings with one Al3+ ion in the SBN–Al3+ complex. The binding mode induces the fluorescence groups of three SBN molecules to exhibit different π–π stacking at different spatial positions, which enables the probe to exhibit fluorescence response signals of different channels. Furthermore, SBN possesses a variety of superior properties, including a short response time, good photostability, a wide pH response range, good anti-interference and low cytotoxicity. Therefore, SBN was successfully applied to dual channel fluorescence detection of Al3+ in the living GS cells of Epinephelus coioides. [ABSTRACT FROM AUTHOR]

In order to improve the walking stability of a biped robot in multiple scenarios and reduce the complexity of the Central Pattern Generator (CPG) model, a new CPG walking controller based on multivariate linear mapping was proposed. At first, in order to establish a dynamics model, the lower limb mechanical structure of the biped robot was designed. According to the Lagrange and angular momentum conservation method, the hybrid dynamic model of the biped robot was established. The initial value of the robot's passive walking was found by means of Poincaré mapping and cell mapping methods. Then, a multivariate linear mapping model was established to form a new lightweight CPG model based on a Hopf oscillator. According to the parameter distribution of the new CPG model, a preliminary parameter-tuning idea was proposed. At last, the joint simulation of MATLAB and V-REP shows that the biped robot based on the new CPG control has a stable periodic gait in flat and uphill scenes. The proposed method could improve the stability and versatility of bipedal walking in various environments and can provide general CPG generation and a tuning method reference for robotics scholars. [ABSTRACT FROM AUTHOR]