3-D Velocity Regulation for Nonholonomic Source Seeking Without Position Measurement

We consider a three-dimensional problem of steering a nonholonomic vehicle to seek an unknown source of a spatially distributed signal field without any position measurement. In the literature, there exists an extremum seeking-based strategy under a constant forward velocity and tunable pitch and yaw velocities. Obviously, the vehicle with a constant forward velocity may exhibit certain overshoots in the seeking process and can not slow down even it approaches the source. To resolve this undesired behavior, this paper proposes a regulation strategy for the forward velocity along with the pitch and yaw velocities. Under such a strategy, the vehicle slows down near the source and stays within a small area as if it comes to a full stop, and controllers for angular velocities become succinct. We prove the local exponential convergence via the averaging technique. Finally, the theoretical results are illustrated with simulations.Comment: submitted to IEEE TCST;12 pages, 10 figure

Catalytic Asymmetric Amino Acid and Its Derivatives by Chiral Aldehyde Catalysis

Amine acid transformation is an important chemical process in biological systems. As a well-developed and acknowledged tool, chiral aldehyde catalysis provides good catalytic activation and stereoselective control abilities in the asymmetric reaction of N-unprotected amino acid esters and amino acid esters analogs, in which the key to success is the design of the catalysts derived from chiral BINOL aldehyde, which is based on the face control of enolate intermediates. In this review, one of the co-catalytic systems that combined with a transition metal to form a multiplex catalytic system and the well-established multiplex stereocenters of chiral aldehyde catalysis have been reviewed. Finally, a novel organocatalysis is prospected

Study on Differences in the Pathology, T Cell Subsets and Gene Expression in Susceptible and Non-Susceptible Hosts Infected with Schistosoma japonicum

More than 40 kinds of mammals in China are known to be naturally infected with Schistosoma japonicum (S. japonicum); Microtus fortis (M. fortis), a species of vole, is the only mammal in which the schistosomes cannot mature or cause significant pathogenic changes. In the current study, we compared the differences in pathology by Hematoxylin-eosin staining and in changes in the T cell subsets with flow cytometry as well as gene expression using genome oligonucleotide microarrays in the lung and liver, before challenge and 10 days post-infection with schistosomes in a S. japonicum-susceptible mouse model of infection, a non-susceptible rat model and the non-permissive host, M. fortis. The results demonstrated that S. japonicum promoted a more intensive immune response and more pathological lesions in M. fortis and rats than in mice. Hematoxylin-eosin staining revealed that the immune effector cells involved were mainly eosinophilic granulocytes supplemented with heterophilic granulocytes and macrophages. The analysis of splenic T cell subsets showed that CD4+ T cell subsets and the CD4+/CD8+ ratio were increased, while the CD8+ T cell subsets decreased remarkably in rats; whereas the CD8+ T cell subsets were increased, but the CD4+/CD8+ ratio was decreased significantly in mice. The analysis of the pattern of gene expression suggested that some immune-associated genes and apoptosis-inducing genes up-regulated, while some development-associated genes were down-regulated in the infected M. fortis compared to the uninfected controls; the three different hosts have different response mechanisms to schistosome infection. The results of this study will be helpful for identifying the key molecules in the immune response to S. japonicum in M. fortis and for understanding more about the underlying mechanism of the response, as well as for elucidating the interaction between S. japonicum and its hosts

Apoptosis Governs the Elimination of Schistosoma japonicum from the Non-Permissive Host Microtus fortis

The reed vole, Microtus fortis, is the only known mammalian host in which schistosomes of Schistosoma japonicum are unable to mature and cause significant pathogenesis. However, little is known about how Schistosoma japonicum maturation (and, therefore, the development of schistosomiasis) is prevented in M. fortis. In the present study, the ultrastructure of 10 days post infection schistosomula from BALB/c mice and M. fortis were first compared using scanning electron microscopy and transmission electron microscopy. Electron microscopic investigations showed growth retardation and ultrastructural differences in the tegument and sub-tegumental tissues as well as in the parenchymal cells of schistosomula from M. fortis compared with those in BALB/c mice. Then, microarray analysis revealed significant differential expression between the schistosomula from the two rodents, with 3,293 down-regulated (by ≥2-fold) and 71 up-regulated (≥2 fold) genes in schistosomula from the former. The up-regulated genes included a proliferation-related gene encoding granulin (Grn) and tropomyosin. Genes that were down-regulated in schistosomula from M. fortis included apoptosis-inhibited genes encoding a baculoviral IAP repeat-containing protein (SjIAP) and cytokine-induced apoptosis inhibitor (SjCIAP), genes encoding molecules involved in insulin metabolism, long-chain fatty acid metabolism, signal transduction, the transforming growth factor (TGF) pathway, the Wnt pathway and in development. TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) and PI/Annexin V-FITC assays, caspase 3/7 activity analysis, and flow cytometry revealed that the percentages of early apoptotic and late apoptotic and/or necrotic cells, as well as the level of caspase activity, in schistosomula from M. fortis were all significantly higher than in those from BALB/c mice

Prognostic value of inflammatory nutritional scores in locally advanced esophageal squamous cell carcinoma patients undergoing neoadjuvant chemoimmunotherapy: a multicenter study in China

ObjectiveThis study investigates the prognostic significance of inflammatory nutritional scores in patients with locally advanced esophageal squamous cell carcinoma (LA-ESCC) undergoing neoadjuvant chemoimmunotherapy.MethodsA total of 190 LA-ESCC patients were recruited from three medical centers across China. Pre-treatment laboratory tests were utilized to calculate inflammatory nutritional scores. LASSO regression and multivariate logistic regression analyses were conducted to pinpoint predictors of pathological response. Kaplan-Meier and Cox regression analyses were employed to assess disease-free survival (DFS) prognostic factors.ResultsThe cohort comprised 154 males (81.05%) and 36 females (18.95%), with a median age of 61.4 years. Pathological complete response (pCR) was achieved in 17.38% of patients, while 44.78% attained major pathological response (MPR). LASSO and multivariate logistic regression analyses identified that hemoglobin, albumin, lymphocyte, and platelet (HALP) (P=0.02) as an independent predictors of MPR in LA-ESCC patients receiving neoadjuvant chemoimmunotherapy. Kaplan-Meier and log-rank tests indicated that patients with low HALP, MPR, ypT1-2, ypN0 and, ypTNM I stages had prolonged DFS (P < 0.05). Furthermore, univariate and multivariate Cox regression analyses underscored HALP (P = 0.019) and ypT (P = 0.029) as independent predictive factors for DFS in ESCC.ConclusionOur study suggests that LA-ESCC patients with lower pre-treatment HALP scores exhibit improved pathological response and reduced recurrence rate. As a comprehensive index of inflammatory nutritional status, pre-treatment HALP may be a reliable prognostic marker in ESCC patients undergoing neoadjuvant chemoimmunotherapy

The Hydromedusae and its distribution in Chukchi Sea and adjacent southern edge waters of Canada Basin, Arctic Ocean

The present paper is based on materials collected in Chukchi Sea and adjacent southern edge waters of Canada Basin, Arctic Ocean during the period from July to August 1999 on the icebreaker, the R/V "Xuelong", by the Chinese First Arctic Scientific Expedition. Totally, 8 species of pelagic Hydromedusae were identified, of which 4 species belonged to Anthomedusae, 2 species to Leptomedusae, 1 species to Trachymedusae and 1 species to Narcomedusae, the Neoturris breviconis is recorded for the first time in Chukchi Sea. Their principal morphological characteristics are described and illustrated. The 8 species of Hydromedusae occurring in the Chukchi Sea were all cold water species. According to the geographic distribution of species, they may be divided into three groups: Arctic species, Arctic-boreal species and Boreal-temperate species. From the view-point of zoogeography, species from these waters belong to the Arctic fauna. The abundance of Hydromedusae in Chukchi Sea was generally low, with a mean value of 108 ind. * 10(-2) * m(-3). Rathkea octop unctata and Aglantha digitale were dominant species. From the view-point of vertical distribution Aglantha digitale is inhabiting in the depth of 0 - 300 m and with the maximum depth of 50 m to 100 m

Combined effects of ultrasonic vibration and manganese on Fe-containing inter-metallic compounds and mechanical properties of Al-17Si alloy with 3wt.%Fe

The research studied the combined effects of ultrasonic vibration (USV) and manganese on the Fe-containing inter-metallic compounds and mechanical properties of Al-17Si-3Fe-2Cu-1Ni (wt.%) alloys. The results showed that, without USV, the alloys with 0.4wt.% Mn or 0.8wt.% Mn both contain a large amount of coarse plate-like δ-Al4(Fe,Mn)Si2 phase and long needle-like β-Al5(Fe,Mn)Si phase. When the Mn content changes from 0.4wt.% to 0.8wt.% in the alloys, the amount and the length of needle-like β-Al5(Fe,Mn)Si phase decrease and the plate-like δ-Al4(Fe,Mn)Si2 phase becomes much coarser. After USV treatment, the Fe-containing compounds in the alloys are refined and exist mainly as δ-Al4(Fe,Mn)Si2 particles with an average grain size of about 20 μm, and only a small amount of β-Al5(Fe,Mn)Si phase remains. With USV treatment, the ultimate tensile strengths (UTS) of the alloys containing 0.4wt.%Mn and 0.8wt.%Mn at room temperature are 253 MPa and 262 MPa, respectively, and the ultimate tensile strengths at 350 °C are 129 MPa and 135 MPa, respectively. It is considered that the modified morphology and uniform distribution of the Fe-containing inter-metallic compounds, which are caused by the USV process, are the main reasons for the increase in the tensile strength of these two alloys

Motion Controller Design Of Autonomous Vehicle

This paper studies the motion control problem of an autonomous vehicle. The problem of the motion control is to control the driving mechanism of the vehicle automatically to track a desired path which may be prescribed or generated on line. A nonlinear two-dimensional wheeled-vehicle model is used. Both linear control and nonlinear state feedback controls are designed for the vehicle to track a circular path when initial disturbances exist. The results show that when the initial disturbance is small, the linear control works well. However, when the initial disturbance is large, nonlinear control has to be used. As a matter of fact, the controller designed in this paper works even when the initial condition is very far away from the desired trajectory

Regionalization of Grassroots Governance and Differences in Class Life Politics: A Case Study of the A Town Industrial Park in Zhuhai

With rapid urbanization, the formation of a governance model for spatial stock has become challenging in building a modern governance system. The process of "domainization" in spatial stock constantly affects the biopolitics of different groups during marketization. This paper introduces the perspective of Foucault's biopolitics based on the domain theory and constructs a domain politics framework indicating a tripartite coupling and interaction among social capital, spatial relations, and life politics. Through semi-structured interviews with, and questionnaires administered to, ordinary workers, middle managers, and top directors, we investigate the changing patterns of workers' biopolitics in the "Territorialization" of grassroots governance. The findings show that the "domainization" process relative to industrial parks has gone through three periods: first, when the state strongly shaped the construction of order and the state economy; second, when the government retreated and capital advanced on a large scale; and third, when there was tripartite competition between the government, workers, and capital. The structures of social capital, spatial relations, and biopolitics experienced a dramatic shift during the succession process of the three periods. The economic attributes of industrial parks shape the various spatial relationships of life and production among workers, middle-level cadres, and top directors, causing differences in the accumulation of social capital for the different classes. The compartmentalization of the spatial field has resulted in a reduction in workers' public activities and the weakening of social capital accumulation. The life politics of workers shifted from self-directed ownership of the A town mechanical farm to early economic dependency, then to full dependency on the park. First, this study bridges the gap in the study of "domainization" in production fields and provides a geo-theoretical perspective for understanding how workers' biopolitics is driven by this process in the context of the transformation in economic production relations. Second, the phenomenon of authority transfer in "domainization" is proposed based on the theory of state-society relations. A detailed explanation of the occurrence of semi-centralized governance in modern society is provided herein. Finally, study findings provide theoretical support and case studies on how sphere politics in grassroots governance affects spatial production relations, achieving integration of the disciplines of politics and geography