When Large Language Model based Agent Meets User Behavior Analysis: A Novel User Simulation Paradigm

User behavior analysis is crucial in human-centered AI applications. In this field, the collection of sufficient and high-quality user behavior data has always been a fundamental yet challenging problem. An intuitive idea to address this problem is automatically simulating the user behaviors. However, due to the subjective and complex nature of human cognitive processes, reliably simulating the user behavior is difficult. Recently, large language models (LLM) have obtained remarkable successes, showing great potential to achieve human-like intelligence. We argue that these models present significant opportunities for reliable user simulation, and have the potential to revolutionize traditional study paradigms in user behavior analysis. In this paper, we take recommender system as an example to explore the potential of using LLM for user simulation. Specifically, we regard each user as an LLM-based autonomous agent, and let different agents freely communicate, behave and evolve in a virtual simulator called RecAgent. For comprehensively simulation, we not only consider the behaviors within the recommender system (\emph{e.g.}, item browsing and clicking), but also accounts for external influential factors, such as, friend chatting and social advertisement. Our simulator contains at most 1000 agents, and each agent is composed of a profiling module, a memory module and an action module, enabling it to behave consistently, reasonably and reliably. In addition, to more flexibly operate our simulator, we also design two global functions including real-human playing and system intervention. To evaluate the effectiveness of our simulator, we conduct extensive experiments from both agent and system perspectives. In order to advance this direction, we have released our project at {https://github.com/RUC-GSAI/YuLan-Rec}.Comment: 26 pages, 9 figure

Occurrence and partitioning behavior of per- and polyfluoroalkyl substances (PFASs) in water and sediment from the Jiulong Estuary-Xiamen Bay, China.

Twenty-four per- and polyfluoroalkyl substances (PFASs) were analyzed in water and sediment from the Jiulong Estuary-Xiamen Bay to study their seasonal variations, transport, partitioning behavior and ecological risks. The total concentration of PFASs in water ranged from 11 to 98 ng L-1 (average 45 ng L-1) during the dry season, 0.19-5.7 ng L-1 (average 1.5 ng L-1) during the wet season, and 3.0-5.4 ng g-1 dw (average 3.9 ng g-1 dw) in sediment. In water samples, short-chain PFASs were dominated by perfluorooctanoic acid (PFBA) in the dry season and perfluorobutane sulfonate (PFBS) in the wet season, while long chain PFASs, such as perfluorooctane sulfonate (PFOS), dominated in the sediment. The highest concentration of PFASs in water were found in the estuary; in contrast, the highest level of PFASs in sediment were found in Xiamen Bay. These spatial distributions of PFASs indicate that river discharge is the main source of PFASs in estuarine water, while the harbor, airport and wastewater treatment plant near Xiamen Bay may be responsible for the high PFBS and PFOS concentrations in water and sediment. The partition coefficients (log Kd) of PFASs between sediment and water (range from 1.64 to 4.14) increased with carbon chain length (R2 = 0.99) and also showed a positive relationship with salinity. A preliminary environmental risk assessment indicated that PFOS and perfluorooctanoic acid (PFOA) in water and sediment pose no significant ecological risk to organisms

A Versatile Method of Engineering the Electron Wavefunction of Hybrid Quantum Devices

With the development of quantum technology, hybrid devices that combine superconductors (S) and semiconductors (Sm) have attracted great attention due to the possibility of engineering structures that benefit from the integration of the properties of both materials. However, until now, none of the experiments have reported good control of band alignment at the interface, which determines the strength of S-Sm coupling and the proximitized superconducting gap. Here, we fabricate hybrid devices in a generic way with argon milling to modify the interface while maintaining its high quality. First, after the milling the atomically connected S-Sm interfaces appear, resulting in a large induced gap, as well as the ballistic transport revealed by the multiple Andreev reflections and quantized above-gap conductance plateaus. Second, by comparing transport measurement with Schr\"odinger-Poisson (SP) calculations, we demonstrate that argon milling is capable of varying the band bending strength in the semiconducting wire as the electrons tend to accumulate on the etched surface for longer milling time. Finally, we perform nonlocal measurements on advanced devices to demonstrate the coexistence and tunability of crossed Andreev reflection (CAR) and elastic co-tunneling (ECT) -- key ingredients for building the prototype setup for realization of Kitaev chain and quantum entanglement probing. Such a versatile method, compatible with the standard fabrication process and accompanied by the well-controlled modification of the interface, will definitely boost the creation of more sophisticated hybrid devices for exploring physics in solid-state systems.Comment: 18 pages, 9 figure

Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30$M_{\odot}$ for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

A G-type lectin receptor-like kinase in Nicotiana benthamiana enhances resistance to the fungal pathogen Sclerotinia sclerotiorum by complexing with CERK1/LYK4

Abstract Fungal pathogens are among the main destructive microorganisms for crops and ecosystems worldwide, causing substantial agricultural and economic losses. Plant cell surface-localized lysin motif (LysM)-containing receptor-like kinases (RLKs) or receptor-like proteins (RLPs) enhance plant resistance to fungal pathogens via sensing chitin, which is a conserved component of the fungal cell wall. Other types of RLKs also regulate chitin signaling via distinct mechanisms in plants. In this study, we identified a G-type lectin RLK, NbERK1, which positively regulated chitin signaling and resistance to the fungal pathogen Sclerotinia sclerotiorum in the model plant Nicotiana benthamiana. In addition, the LysM-RLK NbCERK1/NbLYK4 was shown to mediate plant resistance to S. sclerotiorum positively. Further, the association of chitin-induced NbCERK1-NbLYK4 was found to be essential for chitin perception and signaling. Importantly, NbERK1 was associated with NbCERK1/NbLYK4 and positively regulated chitin-induced NbCERK1-NbLYK4 association. Moreover, chitin could induce the dissociation of NbERK1 from the NbCERK1-NbLYK4 complex. Also, the kinase activity of NbERK1 was likely essential for this dissociation and plant resistance-enhancing activity of NbERK1. Together, these results suggest that NbERK1 is a novel component of the chitin receptor complex and enhances plant resistance to fungal pathogens via regulating chitin signaling

Analysis of Efficacy of Surgical Treatment for IIIa Small Cell Lung Cancer

Background and objective Small cell lung cancer (SCLC) accounts for nearly 15% of all cases of cancer. As a type of highly invasive tumors, SCLC has high degree of malignancy, early and extensive metastasis, and is sensitive to chemotherapy and radiotherapy. The early treatment response rate of SCLC is high but it can also relapse rapidly without any treatment. Its median survival time is merely four to six months. Although many studies on SCLC have been conducted in recent years, its clinical treatment strategies have remained unchanged. The treatment of SCLC is still confined to chemotherapy regimens of etoposide plus cisplatin (EP) and other classic treatments because the surgical treatment of SCLC, particularly for IIIa treatment, has yet to reach a consensus. This study investigated the prognostic factors and clinical therapy effect in the comprehensive treatment of IIIa SCLC after surgical treatment. Methods This study was conducted through the retrospective analysis of the clinical data of 78 patients with SCLC who underwent surgical treatment in Beijing Chest Hospital affiliated to Capital Medical University between January 1995 and December 1995. Through follow-up, we performed statistical analysis of each patient’s gender, age, tumor size, lymph node metastasis, tumor-node-metastasis (TNM) staging, surgical methods, and adjuvant radiation and chemotherapy. Results The median survival in this clinical trial team was 13.93 months. Among the participants, 47 patients accepted neoadjuvant chemotherapy and their median survival were 14.25 months. By contrast, 31 patients accepted postoperative adjuvant chemotherapy and their median survival were 13.83 months. No statistical difference was observed between the two groups. Moreover, 28 patients were of single Lymph node metastasis and their median survival was 17.1 months. By contrast, 50 patients were of multiple lymph node metastasis and their median survival was 11.9 months. Significant statistical difference was observed between the two groups (P<0.01). Conclusion In performing further evaluation of the status and value of surgical treatment in the comprehensive treatment of SCLC, several patients benefitted from IIIa SCLC surgery with comprehensive treatment

Cross-kingdom analyses of transmembrane protein kinases show their functional diversity and distinct origins in protists

Transmembrane kinases (TMKs) are important mediators of cellular signaling cascades. The kinase domains of most metazoan and plant TMKs belong to the serine/threonine/tyrosine kinase (S/T/Y-kinase) superfamily. They share a common origin with prokaryotic kinases and have diversified into distinct subfamilies. Diverse members of the eukaryotic crown radiation such as amoebae, ciliates, and red and brown algae (grouped here under the umbrella term “protists”) have long diverged from higher eukaryotes since their ancient common ancestry, making them ideal organisms for studying TMK evolution. Here, we developed an accurate and high-throughput pipeline to predict TMKomes in cellular organisms. Cross-kingdom analyses revealed distinct features of TMKomes in each grouping. Two-transmembrane histidine kinases constitute the main TMKomes of bacteria, while metazoans, plants, and most protists have a large proportion of single-pass TM S/T/Y-kinases. Phylogenetic analyses classified most protist S/T/Y-kinases into three clades, with clades II and III specifically expanded in amoebae and oomycetes, respectively. In contrast, clade I kinases were widespread in all protists examined here, and likely shared a common origin with other eukaryotic S/T/Y-kinases. Functional annotation further showed that most non-kinase domains were grouping-specific, suggesting that their recombination with the more conserved kinase domains led to the divergence of S/T/Y-kinases. However, we also found that protist leucine-rich repeat (LRR)- and G-protein-coupled receptor (GPCR)-type TMKs shared similar sensory domain architectures with respective plant and animal TMKs, despite that they belong to distinct kinase subfamilies. Collectively, our study revealed the functional diversity of TMKomes and the distinct origins of S/T/Y-kinases in protists