Rho GTPase Signaling Activates Microtubule Severing to Promote Microtubule Ordering in Arabidopsis

SummaryBackgroundOrdered cortical microtubule (MT) arrays play a critical role in the spatial control of cell division and expansion and are essential for plant growth, morphogenesis, and development. Various developmental, hormonal, and mechanical signals and a large number of MT-associated proteins are known to impact cortical MT organization, but the underlying mechanisms remain poorly understood. Our previous studies show that auxin signaling, which is mediated by the ROP6 Rho GTPase and its effector RIC1, promotes the ordering of cortical MTs in pavement cells, but it is unknown how RIC1 controls the organization of cortical MTs into well-ordered arrays.ResultsOur genetic screens identified the conserved MT-severing protein katanin (KTN1) as a downstream component of the ROP6-RIC1 signaling pathway leading to well-ordered arrangement of cortical MTs. KTN1 and RIC1 proteins displayed overlapping localization. In vivo and in vitro studies showed that RIC1 physically interacts with and promotes the MT-severing activity of KTN1. Live-cell imaging reveals a role for RIC1 in promoting detachment of branched MTs that is known to rely on KTN1.ConclusionWe have demonstrated that a Rho GTPase signaling pathway regulates katanin-mediated MT severing in plant cells and uncovered an explicit regulatory mechanism underpinning the alignment and ordering of cortical MTs in plants. Our findings provide new insights into regulatory mechanisms underlying growth stimuli such as auxin promote the organization of cortical MTs into parallel arrays in plants

Effect of thermal ageing on space charge in ethylene propylene rubber at DC voltage

To understand the space charge characteristics of ethylene propylene rubber (EPR) used in MV/HV power cables under thermal stress, the space charge profile is measured by the pulsed electro-acoustic method under 20 kV/mm at 120 and 160 \ub0C. The complex permittivity and physicochemical properties at the different ageing stages are measured and analyzed for an understanding of the effects of thermal ageing on space charge characteristics. The trap properties of EPR during thermal ageing is calculated and analyzed based on the space charge decay model. The results show that both the ageing time and temperature can affect the space charge characteristics of EPR The space charge characteristics of EPR can be ascribed to the trapping sites caused by the complex chemical and physical structures during thermal ageing. Under the thermal oxygen process, the polar groups and ions increase because of the EPR molecular chain breakages, and the charge injection from the electrodes increases. Based on the decay model of space charge and isothermal decay current theory, the distribution of trap levels in EPR at different ageing stages is obtained. The trap distribution under different ageing process can be explained by the theory of trap filling

Germline-Encoded TCR-MHC Contacts Promote TCR V Gene Bias in Umbilical Cord Blood T Cell Repertoire.

T cells recognize antigens as peptides bound to major histocompatibility complex (MHC) proteins through T cell receptors (TCRs) on their surface. To recognize a wide range of pathogens, each individual possesses a substantial number of TCRs with an extremely high degree of variability. It remains controversial whether germline-encoded TCR repertoire is shaped by MHC polymorphism and, if so, what is the preference between MHC genetic variants and TCR V gene compatibility. To investigate the "net" genetic association between MHC variations and TRBV genes, we applied quantitative trait locus (QTL) mapping to test the associations between MHC polymorphism and TCR β chain V (TRBV) genes usage using umbilical cord blood (UCB) samples of 201 Chinese newborns. We found TRBV gene and MHC loci that are predisposed to interact with one another differ from previous conclusions. The majority of MHC amino acid residues associated with the TRBV gene usage show spatial proximities in known structures of TCR-pMHC complexes. These results show for the first time that MHC variants bias TRBV gene usage in UCB of Chinese ancestry and indicate that germline-encoded contacts influence TCR-MHC interactions in intact T cell repertoires

The haptic interaction in virtual surgery based sliding mode control

What operation instruments interact with are human tissues and organs in virtual surgery. Because its impedance is nonlinear and unpredictable, the haptic interaction is difficult to be stable, especially when interacting with rigid tissues such as bone. To solve this difficult problem, this paper presents a sliding mode control algorithm based on Lyapunov theory to realize stable operation for virtual surgery which is never seen in previous research. The simulation results show that 1) the haptic interaction can remain stable when interacting with both soft tissues and large impedance tissues such as bone; 2) the haptic interaction can remain stable even when operation instruments interact with nonlinear impedance tissues.Peer reviewed: YesNRC publication: Ye

Information model of power distribution IoT terminal for high-rise building electrical fire monitoring

Fires caused by electrical reasons such as short circuits and leakage in low-voltage distribution network lines account for a relatively large proportion of the high-rise building fires. Building an electrical fire monitoring system for high-rise buildings based on the Internet of Things (IoTs) technology can monitor electrical circuits in real-time and reduce electrical fires. Aiming at the interconnection and intercommunication of the information exchange of the IoT terminals in the electrical fire monitoring system of high-rise buildings, this paper firstly analyzes the functional communication requirements of the electrical fire monitoring system of high-rise buildings, and combined with the requirements of functional communication, the information model required for electrical quantity collection and non-electricity collection functions is studied based on IEC 61850, which is conducive to the fusion and application of low-voltage distribution network monitoring data and existing distribution automation system data. At the same time, the location information logical node is established by supplementing, which realizes the determination of the spatial position of the terminal and the sensor, the location of the fire source can be determined by analyzing and calculating according to the spatial location information and the spatiotemporal sequence of the detection information. Finally, the information modeling of different types of monitoring terminal equipment is carried out and the configuration suggestion based on SCL language is proposed. By realizing the integration of low-voltage terminal unit (LTU) into the system and the configuration of LTU, the standard system of IEC 61850 can be actually operated. A monitoring terminal based on the proposed information model has been developed and applied to a building in Wuhan

Moving Target Detection and Tracking

Abstract: This study proposes a background update algorithm based on the correlation coefficient, overcome the shortcomings of fuzzy image of the average background updating. Then, it uses subtraction background method to detect moving targets and record the moving target region and use projection histogram to resize the center of the target and calculate the confidence coefficient of the current frame and the subsequent frame to research the center of the target in the subsequent frames. Then, the moving target could be tracked in the subsequent frames. The experimental results show that the algorithm can accurately detect and automatically track moving targets