79 research outputs found
Whole-Chain Recommendations
With the recent prevalence of Reinforcement Learning (RL), there have been
tremendous interests in developing RL-based recommender systems. In practical
recommendation sessions, users will sequentially access multiple scenarios,
such as the entrance pages and the item detail pages, and each scenario has its
specific characteristics. However, the majority of existing RL-based
recommender systems focus on optimizing one strategy for all scenarios or
separately optimizing each strategy, which could lead to sub-optimal overall
performance. In this paper, we study the recommendation problem with multiple
(consecutive) scenarios, i.e., whole-chain recommendations. We propose a
multi-agent RL-based approach (DeepChain), which can capture the sequential
correlation among different scenarios and jointly optimize multiple
recommendation strategies. To be specific, all recommender agents (RAs) share
the same memory of users' historical behaviors, and they work collaboratively
to maximize the overall reward of a session. Note that optimizing multiple
recommendation strategies jointly faces two challenges in the existing
model-free RL model - (i) it requires huge amounts of user behavior data, and
(ii) the distribution of reward (users' feedback) are extremely unbalanced. In
this paper, we introduce model-based RL techniques to reduce the training data
requirement and execute more accurate strategy updates. The experimental
results based on a real e-commerce platform demonstrate the effectiveness of
the proposed framework.Comment: 29th ACM International Conference on Information and Knowledge
Managemen
Authenticated Key Agreement Protocol Based on a Matrix Group and Polynomial Ring over a Finite Field
Alongside encryption and signatures, key agreement is one of the fundamental issues in modern cryptography and its security is the main concern in cloud computing and World Wide Web-based applications. In this paper, a novel type of more secure 3-pass key agreement protocol is proposed based on a recently proposed matrix-based key agreement protocol of RomaĆczuk and Ustimenko. By the hash-and-sign approach and immediate use of new session key, explicit key authentication, forward secrecy and bit security are achieved simultaneously. Cryptanalysis also shows that it is immune to the man-in-the-middle attack while matrix entries from a commutative ring provide an advantageous hiding mechanism
Au@h-Al2O3 Analogic YolkâShell Nanocatalyst for Highly Selective Synthesis of Biomass-Derived D-xylonic Acid via Regulation of Structure Effects
Selective oxidation of biomass-based monosaccharides into value-added sugar acids is highly desired, but limited success of producing D-xylonic acid has been achieved. Herein, we report an efficient catalyst system, viz., Au nanoparticles anchored on the inner walls of hollow Al2O3 nanospheres (Au@h- Al2O3), which could catalyze the selective oxidation of D-xylose into D-xylonic acid under base-free conditions. The mesoporous Al2O3 shell as the adsorbent first adsorbed D-xylose. Then, the interface of Au nanoparticles and Al2O3 as active sites spontaneously dissociated O2, and the exposed Au nanoparticle surface as the catalytic site drove the transformation. With this catalyst system, the valuable D-xylonic acid was produced with excellent yields in the aerobic oxidation of D-xylose. Extensive investigation showed that Au@h- Al2O3 is an efficient catalyst with high stability and recyclability
The effect of cytokines on osteoblasts and osteoclasts in bone remodeling in osteoporosis: a review
The complicated connections and cross talk between the skeletal system and the immune system are attracting more attention, which is developing into the field of Osteoimmunology. In this field, cytokines that are among osteoblasts and osteoclasts play a critical role in bone remodeling, which is a pathological process in the pathogenesis and development of osteoporosis. Those cytokines include the tumor necrosis factor (TNF) family, the interleukin (IL) family, interferon (IFN), chemokines, and so on, most of which influence the bone microenvironment, osteoblasts, and osteoclasts. This review summarizes the effect of cytokines on osteoblasts and osteoclasts in bone remodeling in osteoporosis, aiming to providing the latest reference to the role of immunology in osteoporosis
The relationship between 25-hydroxy vitamin D and serum asprosin in patients with type 2 diabetes in the community
ObjectivesThis study aimed to investigate the link between 25-hydroxy vitamin D and serum asprosin in individuals with type 2 diabetes within the community. The goal was to provide a foundation for clinical interventions.MethodsBetween November 2019 and July 2021, data from 463 patients with type 2 diabetes were consistently gathered at a community health service station in Southeast Shanxi Province. General information and laboratory metrics were compiled, including serum asprosin levels. The participants were categorized based on three serum asprosin quantiles, allowing for a comparison of various factors among the groups. The correlation between serum asprosin levels and other factors was analyzed. Employing a general linear model, the connection between 25-hydroxy vitamin D and serum asprosin levels was studied. Utilizing three quantiles of 25-hydroxy vitamin D, serum asprosin was treated as the dependent variable, while 25-hydroxy vitamin D served as the independent variable for linear regression analysis.ResultsAs serum asprosin increased, there were gradual increments in age, disease duration, SBP, BMI, WC, creatinine, and SUA levels (P<0.05). Conversely, HbA1c, HDL-C, GFR, and 25-hydroxy vitamin D levels exhibited gradual declines (P<0.05). Age, 25-hydroxy vitamin D, SUA, creatinine, and LDL-C emerged as independent influencing factors for serum asprosin. Across the 1st to 3rd 25-hydroxy vitamin D quantiles, elevated 25-hydroxy vitamin D levels correlated with a gradual reduction in mean serum asprosin (P<0.05).ConclusionSerum asprosin levels demonstrate an inverse correlation with 25-hydroxy vitamin D levels in community-dwelling individuals with type 2 diabetes. Serum asprosin levels might independently contribute to 25-hydroxy vitamin D levels
Age-Specific Associations of Renal Impairment With Magnetic Resonance Imaging Markers of Cerebral Small Vessel Disease in Transient Ischemic Attack and Stroke
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Stroke genetics informs drug discovery and risk prediction across ancestries
Previous genome-wide association studies (GWASs) of stroke â the second leading cause of death worldwide â were conducted predominantly in populations of European ancestry1,2. Here, in cross-ancestry GWAS meta-analyses of 110,182 patients who have had a stroke (five ancestries, 33% non-European) and 1,503,898 control individuals, we identify association signals for stroke and its subtypes at 89 (61 new) independent loci: 60 in primary inverse-variance-weighted analyses and 29 in secondary meta-regression and multitrait analyses. On the basis of internal cross-ancestry validation and an independent follow-up in 89,084 additional cases of stroke (30% non-European) and 1,013,843 control individuals, 87% of the primary stroke risk loci and 60% of the secondary stroke risk loci were replicated (Pâ<â0.05). Effect sizes were highly correlated across ancestries. Cross-ancestry fine-mapping, in silico mutagenesis analysis3, and transcriptome-wide and proteome-wide association analyses revealed putative causal genes (such as SH3PXD2A and FURIN) and variants (such as at GRK5 and NOS3). Using a three-pronged approach4, we provide genetic evidence for putative drug effects, highlighting F11, KLKB1, PROC, GP1BA, LAMC2 and VCAM1 as possible targets, with drugs already under investigation for stroke for F11 and PROC. A polygenic score integrating cross-ancestry and ancestry-specific stroke GWASs with vascular-risk factor GWASs (integrative polygenic scores) strongly predicted ischaemic stroke in populations of European, East Asian and African ancestry5. Stroke genetic risk scores were predictive of ischaemic stroke independent of clinical risk factors in 52,600 clinical-trial participants with cardiometabolic disease. Our results provide insights to inform biology, reveal potential drug targets and derive genetic risk prediction tools across ancestries
Post-traumatic right carotid-cavernous fistula resulting in symptoms in the contralateral eye: a case report and literature review
Abstract Background To report a case of a carotid-cavernous fistula (CCF) that occurred after a motor vehicle accident and review the uniqueness of this case and the main confusing points for the diagnosis of such cases. Case presentation A 22-year-old man complained of left eyelid swelling, eye redness, visual decrease and occasional headache after motor vehicle accident 4Â months prior during which he experienced a head injury. He was initially thought to have glaucoma, but he was finally diagnosed with a right CCF based on magnetic resonance imaging (MRI) and digital subtraction angiography (DSA). Timely embolization surgery resulted in obvious relief of the ocular symptoms and an improved prognosis. Conclusion This is the first reported case of a post-traumatic unilateral CCF with contralateral symptoms in direct CCF, it is very infrequent and deserves our attention. We should maintain high suspicion of CCF and confirm the diagnosis by DSA when managing such patients to prevent serious consequences. Early diagnosis and treatment can improve the prognosis of patients
Water use efficiency at multi-time scales and its response to episodic drought and wet periods in a typical subtropical evergreen forest of Southeast China
Water use efficiency (WUE) quantifies the trade-off between carbon gain and water loss. A deep understanding of its relationships with the controlling factors is essential for predicting ecosystem responses to climate change. Our study utilized the eddy covariance measurements to analyze the variability of WUE and its influencing climate factors at the seasonal, monthly, 8-day, daily, and half-hourly scales and during the episodic drought and wet periods at a typical subtropical evergreen forest of Southeast China. The results show that ET is the dominant factor influencing the WUE variability with a relative contribution of 57.56 ± 2.26% for different seasons in this study area. Secondly, WUE responds differently to climatic drivers from monthly to half-hourly scales. Our results show that WUE has a remarkably high sensitivity to soil moisture at multi-time scales (from monthly to half-hourly), and the connection strength increases with increasing time scale. Thirdly, there is no significant relationship between VPD and WUE as time scale expands. In addition, WUEs during the episodic drought period have higher values than those during the episodic wet period on the monthly scales. The half-hourly WUE during the episodic drought period is close to the WUE during the episodic wet period from 8:30 to 19:00 but is higher from 6:00 to 8:00. These results indicate that soil moisture plays an important role on influencing WUE variation at multi-time scales and under extreme climatic conditions
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