164 research outputs found
Optimized state estimation for nonlinear dynamical networks subject to fading measurements and stochastic coupling strength: An event-triggered communication mechanism
summary:This paper is concerned with the design of event-based state estimation algorithm for nonlinear complex networks with fading measurements and stochastic coupling strength. The event-based communication protocol is employed to save energy and enhance the network transmission efficiency, where the changeable event-triggered threshold is adopted to adjust the data transmission frequency. The phenomenon of fading measurements is described by a series of random variables obeying certain probability distribution. The aim of the paper is to propose a new recursive event-based state estimation strategy such that, for the admissible linearization error, fading measurements and stochastic coupling strength, a minimum upper bound of estimation error covariance is given by designing the estimator gain. Furthermore, the monotonicity relationship between the trace of the upper bound of estimation error covariance and the fading probability is pointed out from the theoretical aspect. Finally, a simulation example is used to show the effectiveness of developed state estimation algorithm
Religious atmosphere, seismic impact, and corporate charitable donations in China
This study examines the external socio-cultural and natural environment factors that driving corporate philanthropy in China. We focus on two predominant influences: religiosity, specifically the traditional Three-Teachings (Confucianism, Buddhism, and Taoism), and seismic activities. Using a large sample of 31,673 firm-year observations from Chinese listed firms from 2009 to 2020, our findings reveal that (a) firms immersed in more pronounced religious-cultural presence have higher donation incentives, and (b) firms experiencing higher seismic impacts or are located in high seismic risk areas show heightened corporate philanthropic tendencies. Our multidisciplinary approach bridges various academic disciplines, presenting an innovative framework for understanding the intersection of corporate philanthropy, socio-cultural environments, and natural disasters in China. Overall, we highlight the importance of external environmental factors in shaping corporate charitable behaviours
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Synthesis of a molecularly defined single-active site heterogeneous catalyst for selective oxidation of N-heterocycles
Generally, a homogeneous catalyst exhibits good activity and defined active sites but it is difficult to recycle. Meanwhile, a heterogeneous catalyst can easily be reused but its active site is difficult to reveal. It is interesting to bridge the gap between homogeneous and heterogeneous catalysis via controllable construction of a heterogeneous catalyst containing defined active sites. Here, we report that a molecularly defined, single-active site heterogeneous catalyst has been designed and prepared via the oxidative polymerization of maleimide derivatives. These polymaleimide derivatives can be active catalysts for the selective oxidation of heterocyclic compounds to quinoline and indole via the recycling of -C=O and -C-OH groups, which was confirmed by tracing the reaction with GC-MS using maleimide as the catalyst and by FT-IR analysis with polymaleimide as the catalyst. These results might promote the development of heterogeneous catalysts with molecularly defined single active sites exhibiting a comparable activity to homogeneous catalysts
Theory and application of mining mechanics and strata control
Studying the dynamic response of rock mass mining and strata control technology is of great significance for promoting safe and efficient coal production and ensuring stable energy supply. It is the theoretical basis for scientific mining of coal resources. Mine rock mass disasters (surrounding rock deformation, rock burst, etc.) occur frequently, and their formation-evolution-occurrence process is closely related to the evolution and distribution of mine-induced stress, strata movement, mine-induced disturbance and energy evolution. Based on the practical theory of ground pressure control, the progress and control criteria of strata control in the stope are presented. The mechanical models and design methods for quantitative analysis are established. Also, the targeted rock disaster control technology and the assorted equipment are innovatively developed. In the theory of mining mechanics and strata control, the strata control is divided into rock control in stope and surrounding rock control in roadway. The control or utilization of strata movement to change the conditions of disaster is proposed, and the criteria of âgiven deformationâ and âlimited deformationâ are provided. The self-stabilization ability of surrounding rock can be changed by regulating the â3Sâ factors criteria (stress environment, structural properties, and support structure). With the goal of controlling rock mass disasters, the system of control and energy release with core of stress control in roadway surrounding rock is presented. The principle of rock mass disaster control considering stress and energy and the assessment criteria for weak surface (safety factor K and impact hazard factor U) are established. The ground pressure mechanical simulation test system in stope, the mining-induced stress test system, and the creep and dynamic disturbance impact loading test system are independently developed. The series equipment can realize the laboratory-scale reduction of the deformation-fracture-movement process of rock mass under the action of mine-induced stress, providing experimental equipment for studying the mechanical response of rock mass. Engineering case studies are conducted from four directions: rock control in the mining area, geological soft rock control, engineering soft rock roadway control, and rockburst control. The relevant research results are validated in engineering applications
Rethink Baseline of Integrated Gradients from the Perspective of Shapley Value
Numerous approaches have attempted to interpret deep neural networks (DNNs)
by attributing the prediction of DNN to its input features. One of the
well-studied attribution methods is Integrated Gradients (IG). Specifically,
the choice of baselines for IG is a critical consideration for generating
meaningful and unbiased explanations for model predictions in different
scenarios. However, current practice of exploiting a single baseline fails to
fulfill this ambition, thus demanding multiple baselines. Fortunately, the
inherent connection between IG and Aumann-Shapley Value forms a unique
perspective to rethink the design of baselines. Under certain hypothesis, we
theoretically analyse that a set of baseline aligns with the coalitions in
Shapley Value. Thus, we propose a novel baseline construction method called
Shapley Integrated Gradients (SIG) that searches for a set of baselines by
proportional sampling to partly simulate the computation path of Shapley Value.
Simulations on GridWorld show that SIG approximates the proportion of Shapley
Values. Furthermore, experiments conducted on various image tasks demonstrate
that compared to IG using other baseline methods, SIG exhibits an improved
estimation of feature's contribution, offers more consistent explanations
across diverse applications, and is generic to distinct data types or instances
with insignificant computational overhead.Comment: 12 page
Association between immunoglobulin G N-glycosylation and lupus nephritis in female patients with systemic lupus erythematosus: A case-control study
Background: Lupus nephritis (LN) is a crucial complication of systemic lupus erythematosus (SLE) and has important clinical implications in guiding treatment. N-glycosylation of immunoglobulin G (IgG) plays a key role in the development of SLE by affecting the balance of anti-inflammatory and proinflammatory responses. This study aimed to evaluate the performance of IgG N-glycosylation for diagnosing LN in a sample of female SLE patients. Methods: This case-control study recruited 188 women with SLE, including 94 patients with LN and 94 age-matched patients without LN. The profiles of plasma IgG N-glycans were detected by hydrophilic interaction chromatography with ultra-performance liquid chromatography (HILIC-UPLC). A multivariate logistic regression model was used to explore the associations between IgG N-glycans and LN. A diagnostic model was developed using the significant glycans as well as demographic factors. The performance of IgG N-glycans in the diagnosis of LN was evaluated by receiver operating characteristic (ROC) curve analysis, and the area under the curve (AUC) and its 95% confidence interval (CI) were calculated. Results: There were significant differences in 9 initial glycans (GP2, GP4, GP6, GP8, GP10, GP14, GP16, GP18 and GP23) between women with SLE with and without LN (P \u3c 0.05). The levels of sialylated, galactosylated and fucosylated glycans were significantly lower in the LN patients than in the control group, while bisected N-acetylglucosamine (GlcNAc) glycans were increased in LN patients (P \u3c 0.05). GP8, GP10, GP18, and anemia were included in our diagnostic model, which performed well in differentiating female SLE patients with LN from those without LN (AUC = 0.792, 95% CI: 0.727 to 0.858). Conclusion: Our findings indicate that decreased sialylation, galactosylation, and core fucosylation and increased bisecting GlcNAc might play a role in the development of LN by upregulating the proinflammatory response of IgG. IgG N-glycans can serve as potential biomarkers to differentiate individuals with LN among SLE patients
Discrete Element Simulation of the Macro-Meso Mechanical Behaviors of Gas-Hydrate-Bearing Sediments under Dynamic Loading
Under the action of dynamic loadings such as earthquakes and volcanic activities, the mechanical properties of gas-hydrate-bearing sediments will deteriorate, leading to a decrease in the stability of hydrate reservoirs and even inducing geological disasters such as submarine landslides. In order to study the effect of dynamic loading on the mechanical properties of hydrate sediments, triaxial compression tests of numerical specimens were carried out by using particle flow code (PFC2D), and the macro-meso mechanical behaviors of specimens were investigated. The results show that the loading frequency has a small effect on the stiffness of the hydrate sediment, while it has a large effect on the peak strength. The peak strength increases and then decreases with the increase in loading frequency. Under the same loading frequency, the peak strength of the hydrate sediment increases with the increase in loading amplitude, and the stiffness of the specimen decreases with the increase in loading amplitude. The maximum shear expansion of the specimen changes with the movement of the phase change point and the rearrangement of the particles. The maximum shear expansion of the specimen changes with the movement of the phase change point and the change of the bearing capacity of the particles after the rearrangement, and the more forward the phase change point is, the stronger the bearing capacity of the specimen in the plastic stage. The shear dilatancy angle and the shear dilatancy amount both increase linearly with the increase in loading amplitude. The influence of loading frequency and amplitude on the contact force chain, displacement, crack expansion, and the number of cementation damage inside the sediment is mainly related to the average axial stress to which the specimen is subjected, and the number of cracks and cementation damage of the sediment specimen increases with the increase in the average axial stress to which the sediment specimen is subjected. As the rate of cementation damage increases, the distribution of shear zones becomes more obvious
Shufeng Jiedu Capsules Alleviate Lipopolysaccharide-Induced Acute Lung Inflammatory Injury via Activation of GPR18 by Verbenalin
Background/Aims: Acute respiratory tract infection (ARTI) is the most common reason for outpatient physician office visits. Although powerful and significant in the treatment of infections, antibiotics used for ARTI inappropriately have been an important contributor to antibiotic resistance. We previously reported that Shufeng Jiedu Capsule (SJC) can effectively amplify anti-inflammatory signaling during infection. In this study, we aimed to systematically explore its composition and the mechanism of its effects in ARTI. Methods: Pseudomonas aeruginosa (PAK) strain was used to generate a mouse model of ARTI, which were then treated with different drugs or compounds to determine the corresponding anti-inflammatory roles. High-performance liquid chromatography-quadrupole time of flight-tandem mass spectrometry. was conducted to detect the chemical compounds in SJC. RNAs from the lung tissues of mice were prepared for microarray analysis to reveal globally altered genes and the pathways involved after SJC treatment. Results: SJC significantly inhibited the expression and secretion of inflammatory factors from PAK-induced mouse lung tissues or lipopolysaccharide-induced peritoneal macrophages. Verbenalin, one of the bioactive compounds identified in SJC, also showed notable anti-inflammatory effects. Microarray data revealed numerous differentially expressed genes among the different treatment groups; here, we focused on studying the role of GPR18. We found that the anti-inflammatory role of verbenalin was attenuated in GPR18 knockout mice compared with wild-type mice, although no statistically significant difference was observed in the untreated PAK-induced mice types. Conclusion: Our data not only showed the chemical composition of SJC, but also demonstrated that verbenalin was a significant anti-inflammatory compound, which may function through GPR18
Cooperation-based sperm clusters mediate sperm oviduct entry and fertilization
Sperm cooperation has been observed in multiple species, yet its existence and benefit for reproductive success in mammals remains underexplored. Here, combining tissue-clearing with deep three-dimensional imaging, we demonstrate that postcopulatory mouse sperm congregate into unidirectional sperm cooperative clusters at the utero-tubal junction (UTJ), a key physical barrier for passage into the oviduct. Reducing sperm number in male mice by unilateral vasoligation or busulfan-treatment impairs sperm cluster formation and oviduct entry. Interestingly, sperm derived from Tex101-/- mouse has normal number, motility and morphology, yet they cannot form sperm cluster and fail to pass through the UTJ, which is at least in part due to the altered tail beating pattern of the Tex101-/- sperm. Moreover, Tex101-/- sperm's defect in oviduct entry cannot be rescued by the presence of wild-type (WT) sperm in the same uteri by sequential mating, suggesting sperm cooperative cluster as an essential behavior contributing to male fertility, which could be related to human infertility or subfertility
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