Approximately 180 million people worldwide are affected by Viral hepatitis C, with 350,000 to 500,000 deaths yearly. The present study sought to investigate the prevalence and associated factors of viral hepatitis C (...Approximately 180 million people worldwide are affected by Viral hepatitis C, with 350,000 to 500,000 deaths yearly. The present study sought to investigate the prevalence and associated factors of viral hepatitis C (VHC) among the Burundian population during a screening campaign. A total of 629 participants took part in the study, and the prevalence of viral hepatitis C was (8.11%). The associated factors identified as statistically associated were medical and surgical history (P = 0.02) and ear and nose piercing (P = 0.01). 51% of the infected persons were females. The mean age for viral hepatitis C carriage was 46.13 ± 14.3 years and 10.40% of viral hepatitis C carriers were over 50 years old. We found a high viral hepatitis C prevalence in married (9.55%) and divorced (9.38%) participants. The majority of our participants were farmers (60.25%) with a prevalence of viral hepatitis C (7.92%) while 11.54% of the infected participants were not educated. In conclusion, the current study shows a high prevalence of Viral Hepatitis C infection in Burundi. Infection was more likely to occur in older, married, farmer, and illiterates. Unsafe medical and surgical interventions with traditional practitioners were significant risk factors for contracting VHC infection.展开更多
Periodic motion planning for an under-actuated system is rather difficult due to differential dynamic constraints imposed by passive dynamics, and it becomes more difficult for a system with higher underactuation degr...Periodic motion planning for an under-actuated system is rather difficult due to differential dynamic constraints imposed by passive dynamics, and it becomes more difficult for a system with higher underactuation degree, that is with a higher difference between the number of degrees of freedom and the number of independent control inputs. However, from another point of view, these constraints also mean some relation between state variables and could be used in the motion planning.We consider a double rotary pendulum, which has an underactuation degree 2. A novel periodic motion planning is presented based on an optimization search. A necessary condition for existence of the whole periodic trajectory is given because of the higher underactuation degree of the system. Moreover this condition is given to make virtual holonomic constraint(VHC) based control design feasible. Therefore, an initial guess for the optimization of planning a feasible periodic motion is based on this necessary condition. Then, VHCs are used for the system transformation and transverse linearization is used to design a static state feedback controller with periodic matrix function gain. The controller gain is found through another optimization procedure. The effectiveness of initial guess and performance of the closed-loop system are illustrated through numerical simulations.展开更多
文摘Approximately 180 million people worldwide are affected by Viral hepatitis C, with 350,000 to 500,000 deaths yearly. The present study sought to investigate the prevalence and associated factors of viral hepatitis C (VHC) among the Burundian population during a screening campaign. A total of 629 participants took part in the study, and the prevalence of viral hepatitis C was (8.11%). The associated factors identified as statistically associated were medical and surgical history (P = 0.02) and ear and nose piercing (P = 0.01). 51% of the infected persons were females. The mean age for viral hepatitis C carriage was 46.13 ± 14.3 years and 10.40% of viral hepatitis C carriers were over 50 years old. We found a high viral hepatitis C prevalence in married (9.55%) and divorced (9.38%) participants. The majority of our participants were farmers (60.25%) with a prevalence of viral hepatitis C (7.92%) while 11.54% of the infected participants were not educated. In conclusion, the current study shows a high prevalence of Viral Hepatitis C infection in Burundi. Infection was more likely to occur in older, married, farmer, and illiterates. Unsafe medical and surgical interventions with traditional practitioners were significant risk factors for contracting VHC infection.
基金supported by China Scholarship Council (201504980073) for Zeguo Wang to visit Umea University
文摘Periodic motion planning for an under-actuated system is rather difficult due to differential dynamic constraints imposed by passive dynamics, and it becomes more difficult for a system with higher underactuation degree, that is with a higher difference between the number of degrees of freedom and the number of independent control inputs. However, from another point of view, these constraints also mean some relation between state variables and could be used in the motion planning.We consider a double rotary pendulum, which has an underactuation degree 2. A novel periodic motion planning is presented based on an optimization search. A necessary condition for existence of the whole periodic trajectory is given because of the higher underactuation degree of the system. Moreover this condition is given to make virtual holonomic constraint(VHC) based control design feasible. Therefore, an initial guess for the optimization of planning a feasible periodic motion is based on this necessary condition. Then, VHCs are used for the system transformation and transverse linearization is used to design a static state feedback controller with periodic matrix function gain. The controller gain is found through another optimization procedure. The effectiveness of initial guess and performance of the closed-loop system are illustrated through numerical simulations.
