Hardware implementation of Lorenz circuit systems for secure chaotic communication applications.

This paper presents the synchronization between the master and slave Lorenz chaotic systems by slide mode controller (SMC)-based technique. A proportional-integral (PI) switching surface is proposed to simplify the task of assigning the performance of the closed-loop error system in sliding mode. Then, extending the concept of equivalent control and using some basic electronic components, a secure communication system is constructed. Experimental results show the feasibility of synchronizing two Lorenz circuits via the proposed SMC. 

Effect of various forearm axially rotated postures on elbow load and elbow flexion angle in one-armed arrest of a forward fall.

BACKGROUND: Falling onto the outstretched hand is a major cause of upper extremity injury. The overall objectives of this study were to develop an experimental model for elbow load during a simulated fall onto one-armed arrest using three different forearm axially rotated postures as alternative fall arrest strategies. Additionally, the relationship between the elbow flexion angle and different axially rotated postures were also investigated. METHODS: Fifteen healthy young male Taiwanese graduate students with an average age of 23 years were studied. Subjects performed a one-armed arrest of a 5 cm fall onto a force plate. Each subject fell onto the force plate with his forearm 45 degrees axial externally rotated (ER), non-rotated (NR), and 45 degrees axial internally rotated (IR) postures. Kinematics and kinetics of the upper extremity were calculated and analyzed by using laboratory-developed motion analysis procedures. FINDINGS: The valgus-varus shear forces in the ER group were 1.4 times greater than the NR group, and 2.7 times greater than the IR group. The elbow joint remained at almost full extension in the ER (3.9 degrees) group, while elbow flexion angle was observed in the NR (24.6 degrees) and IR (40.3 degrees) groups. INTERPRETATION: A fall onto the outstretched hand with an externally rotated forearm should be avoided in order to reduce excessive valgus-varus shear force on the elbow joint. Knowledge of elbow kinematics and kinetics during a forward fall with various forearm axially rotated posture may be helpful in preventing injuries.

Involvement of MAPKs, NF-kappaB and p300 co-activator in IL-1beta-induced cytosolic phospholipase A2 expression in canine tracheal smooth muscle cells.

Cytosolic phospholipase A2 (cPLA2) plays a pivotal role in mediating agonist-induced arachidonic acid release for prostaglandin (PG) synthesis during stimulation with interleukin-1beta (IL-1beta). However, the mechanisms underlying IL-1beta-induced cPLA2 expression and PGE2 synthesis by canine tracheal smooth muscle cells (CTSMCs) have not been defined. IL-1beta induced cPLA2 protein and mRNA expression, PGE2 production, and phosphorylation of p42/p44 MAPK, p38 MAPK (ATF2), and JNK (c-Jun) in a time- and concentration-dependent manner, determined by Western blotting, RT-PCR, and ELISA, which was attenuated by the inhibitors of MEK1/2 (U0126), p38 MAPK (SB202190), and JNK (SP600125), or transfection with dominant negative mutants of MEK1/2, p38, and JNK, respectively. Furthermore, IL-1beta-induced cPLA2 expression and PGE2 synthesis was inhibited by a selective NF-kappaB inhibitor (helenalin) or transfection with dominant negative mutants of NF-kappaB inducing kinase (NIK), IkappaB kinase (IKK)-alpha, and IKK-beta. Consistently, IL-1beta stimulated both IkappaB-alpha degradation and NF-kappaB translocation into nucleus in these cells. NF-kappaB translocation was blocked by helenalin, but not by U0126, SB202190, and SP600125. MAPKs together with NF-kappaB-activated p300 recruited to cPLA2 promoter thus facilitating the binding of NF-kappaB to cPLA2 promoter region and expression of cPLA2 mRNA. IL-1beta-induced cPLA2 expression and PGE2 production was inhibited by actinomycin D and cycloheximide, indicating the involvement of transcriptional and translational events in these responses. These results suggest that in CTSMCs, IL-1beta-induced cPLA2 expression and PGE2 synthesis was independently mediated through activation of MAPKs and NF-kappaB pathways and was connected to p300 recruitment and activation.