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Tissue-specific gene knockout by CRISPR/Cas9 is a powerful approach for characterizing gene functions during development. However, this approach has not been successfully applied to most Drosophila tissues, including the Drosophila neuromuscular junction (NMJ). To expand tissue-specific CRISPR to this powerful model system, here we present a CRISPR-mediated tissue-restricted mutagenesis (CRISPR-TRiM) toolkit for knocking out genes in motoneurons, muscles, and glial cells. We validated the efficacy of CRISPR-TRiM by knocking out multiple genes in each tissue, demonstrated its orthogonal use with the Gal4/UAS binary expression system, and showed simultaneous knockout of multiple redundant genes. We used CRISPR-TRiM to discover an essential role for SNARE components in NMJ maintenance. Furthermore, we demonstrate that the canonical ESCRT pathway suppresses NMJ bouton growth by downregulating retrograde Gbb signaling. Lastly, we found that axon termini of motoneurons rely on ESCRT-mediated intra-axonal membrane trafficking to release extracellular vesicles at the NMJ. Thus, we have successfully developed an NMJ CRISPR mutagenesis approach which we used to reveal genes important for NMJ structural plasticity. Author summary: We have developed a tissue-specific Cas9 toolkit that enables gene knockout specifically in motor neurons, glial cells, and muscle cells, the three principle cell types of the Drosophila peripheral motor system. Complementary to existing RNAi methods, this versatile tissue-specific knockout system offers unique advantages for dissecting gene functions at the neuromuscular junction (NMJ). Using these tools, we discovered that SNARE-mediated secretory pathways are required to maintain the integrity of the NMJ and that ESCRT components play critical yet differential roles in the biogenesis of extracellular vesicles, bouton growth, and membrane turnover at the NMJ. This CRISPR toolkit can be applied to study many biological questions in the neuromuscular system. [ABSTRACT FROM AUTHOR]

As soon as the play Forging the Truth (Nongzhen chengjia, 1943) written by the Chinese scholar Yang Jiang (1911-2016) premiered during World War II, critics considered the work to be the second milestone of the Chinese comedy of manners. This comment is unsurprising since Yang had a longstanding scholarly interest in the British comedy of manners tradition, especially those by Jane Austen (1775-1817). Also an academic and writer, Yang’s husband, Qian Zhongshu (1910-1998), after watching the play, began writing his only published novel, Fortress Besieged (1947). Given Qian’s inseparable fellowship with Yang Jiang, his irrefutable grounding in Chinese and European arts and letters, and exploration of how marriage impacts the individual in the novel, one wonders why scholars have not recognised even one female author among his source influences. This article establishes a link between Austen and Qian by integrating biographical accounts, a scholarship work Yang had done, and close readings of Jane Austen’s Pride and Prejudice (1813), Yang Jiang’s Nongzhen chengjia, and Qian Zhongshu’s Fortress Besieged. By looking at their adaptations of the comedy of manners genre, this article expands on a common quality the three works all share: the duality of playful irony and intelligent compassion.

This paper presents a sliding mode dynamic surface control strategy for multi-machine power systems with static var compensator (SVC) to design the controller of the generator excitation system. Firstly, compared with the existing control methods, the combination of sliding mode control and dynamic surface control improves the robustness of the system and avoids the "explosion of complexity" problems. Subsequently, the fuzzy logic system is introduced to estimate the unknown continuous function in power system, and the norm of the weight vector is used to replace the estimation of the entire weight vector. In this way, computational burden will be reduced. In addition, the influences of unknown time delays and dead-zones are considered. Finite cover lemma is introduced to deal with unknown time delays, which enables arbitrarily small L ∞ tracking performance. The unknown dead-zone is converted into the sum of linear dead zone and bounded nonlinear dead zone. Finally, the simulation results are provided to validate the feasibility and effectiveness of the proposed control strategy. [ABSTRACT FROM AUTHOR]