Consensus for Second-Order Discrete-Time Agents With Position Constraints and Delays.

This article addresses a consensus problem of second-order discrete-time agents in general directed networks with nonuniform position constraints, switching topologies, and communication delays. A projection operation is performed to ensure the agents stay in some given convex sets, and a distributed algorithm is employed for the consensus achievement of all agents. The analysis approach is to use a linear transformation to convert the original system into an equivalent system and then merge the nonlinear error term into the convex null of the agents' states so as to prove the consensus convergence of the system based on the properties of the non-negative matrices. It is shown that all agents finally converge to a consensus point while their positions stay in the corresponding constraint sets as long as the union of the communication graphs among each certain time interval is strongly connected even when the communication delays are considered. Finally, numerical simulation examples are given to show the theoretical results.

Treatment Efficacy and Risk Factors of Neurobrucellosis.

BACKGROUND: This study aimed to analyze the risk factors and treatment efficacy of neurobrucellosis. MATERIAL/METHODS: A cross-sectional epidemiologic survey was carried out in 557 patients with brucellosis by specially trained neurologic clinicians. Sixty-six patients with neurobrucellosis were treated with doxycycline, rifampicin, and ceftriaxone sodium as standard medication and evaluated for efficacy on a regular basis. RESULTS: (1) Symptoms improved in most patients after 6 weeks of treatment, which demonstrated a favorable efficacy. (2) Cross-sectional epidemiologic survey suggested that sex, nationality, and regional distribution were not related to nervous system damage in patients with brucellosis (P>0.05), whereas age and duration of disease were related factors. Increased age as well as a prolonged duration of disease were risk factors for nervous system damage in patients with brucellosis (P<0.05). CONCLUSIONS: (1) Doxycycline, rifampicin, and third-generation cephalosporins should be considered both standard and first-choice medications for neurobrucellosis. Treatment should last for at least 6 weeks. Standardized, sufficient, and combined medication is recommended for better efficacy and prognosis. (2) Age and duration of disease are risk factors for neurobrucellosis, whereas sex, nationality, and regional distribution are not. Older patients with a prolonged duration of disease are more likely to develop neurobrucellosis.