ABSTRACT
Informed by some relevant theories of positive psychology, the current study examined the interrelations among teacher support, grit, and L2 willingness to communicate (WTC), focusing mainly on the mediating role of foreign language enjoyment (FLE). A sample of 619 university students in China participated in this cross-sectional survey. Structural equation modeling (SEM) was used to analyze the gathered data. The results showed that grit could directly and positively predict L2 WTC. Furthermore, teacher support and grit could affect L2 WTC via the mediating role of FLE. These findings served as empirical evidence from the second language acquisition (SLA) domain for positive psychology, revealing the influential mechanism shaping the interconnectedness among all the constructs. The study concluded with a discussion of pedagogical implications and suggestions for future research.
Subject(s)
Multilingualism , Students , Humans , Male , Female , Cross-Sectional Studies , Young Adult , Adult , China , Students/psychology , Students/statistics & numerical data , School Teachers/psychology , Communication , Universities , Social Support , AdolescentABSTRACT
Balamuthia mandrillaris amebic encephalitis (BAE) can cause a fatal condition if diagnosis is delayed or effective treatment is lacking. Patients with BAE have been previously reported in 12 provinces of China, with skin lesions being the primary symptom and encephalitis developing after several years. However, a significantly lower number of cases has been reported in Southwest China. Here we report an aggressive BAE case of a 64-year-old woman farmer with a history of skin lesions on her left hand. She was admitted to our hospital due to symptoms of dizziness, headache, cough, vomiting, and gait instability. She was initially diagnosed with syphilitic meningoencephalitis and received a variety of empirical treatment that failed to improve her symptoms. Finally, she was diagnosed with BAE combined with amebic pneumonia using next-generation sequencing (NGS), qRT-PCR, sequence analysis, and imaging studies. She died approximately 3 weeks after the onset. This case highlights that the rapid development of encephalitis can be a prominent clinical manifestation of Balamuthia mandrillaris infection.
Subject(s)
Amebiasis , Amoeba , Balamuthia mandrillaris , Central Nervous System Protozoal Infections , Encephalitis , Infectious Encephalitis , Humans , Female , Middle Aged , Central Nervous System Protozoal Infections/diagnosis , Encephalitis/diagnosis , Amebiasis/diagnosis , ChinaABSTRACT
In this paper, the cascade control (CC), a structure popular among practitioners in many industry sectors, is used to bridge the two prominent research methodologies in SMC and ADRC for the purpose of multi-axis motion synchronization. In particular, the cascade sliding mode control(C-SMC) is first proposed, from which the cascade active disturbance rejection control (C-ADRC) is derived. This allows the linear and fal-function based nonlinear control actions to be naturally integrated and the controller parameters can be tuned easily with the proposed space-time scaling method. The control law is constructed and validated in multi-axis motion synchronization of parallel mechanisms. The results show that the proposed scheme is effective and practical, with the robustness associated with the bandwidth constraints.
ABSTRACT
A bandwidth-parameterized active disturbance rejection synchronization control (ADRSC) is proposed for the parallel electro-coating conveyor. The Laplacian matrix is extracted from the newly defined adjacent-cross-coupling errors and embedded in the controller. It is shown that the proposed ADRSC possesses the capability to achieve synchronization by reformulating cross-coupling as average disturbance to be rejected, thus reducing the dynamics to the canonical form of chained integrators. Furthermore, the upper bound of the bandwidth is established as the trade-off between the accuracy of synchronization and stability. The main contribution of this paper is to extend the active disturbance rejection principle to the accommodation of cross-coupling in synchronization. Simulations and experiments show that this proposed method is effective and practical.
