Thermally multiplexed polymerase chain reaction

Amplification of multiple unique genetic targets using the polymerase chain reaction (PCR) is commonly required in molecular biology laboratories. Such reactions are typically performed either serially or by multiplex PCR. Serial reactions are time consuming, and multiplex PCR, while powerful and widely used, can be prone to amplification bias, PCR drift, and primer-primer interactions. We present a new thermocycling method, termed thermal multiplexing, in which a single heat source is uniformly distributed and selectively modulated for independent temperature control of an array of PCR reactions. Thermal multiplexing allows amplification of multiple targets simultaneously—each reaction segregated and performed at optimal conditions. We demonstrate the method using a microfluidic system consisting of an infrared laser thermocycler, a polymer microchip featuring 1 μl, oil-encapsulated reactions, and closed-loop pulse-width modulation control. Heat transfer modeling is used to characterize thermal performance limitations of the system. We validate the model and perform two reactions simultaneously with widely varying annealing temperatures (48 °C and 68 °C), demonstrating excellent amplification. In addition, to demonstrate microfluidic infrared PCR using clinical specimens, we successfully amplified and detected both influenza A and B from human nasopharyngeal swabs. Thermal multiplexing is scalable and applicable to challenges such as pathogen detection where patients presenting non-specific symptoms need to be efficiently screened across a viral or bacterial panel.     

Three-dimensional kinematic analysis of the golf swing using instantaneous screw axis theory,Part 2: golf swing kinematic sequence

A number of recent studies have measured the extent and timing of segment rotation during the golf swing. A promising technique, instantaneous screw axis (ISA) theory, could provide a better expression of segment rotation. In Part 1 of this two-part study, the objectives are to identify the ISA of the pelvis, shoulders and left arm during the downswing, compute segment angular velocity relative to that segment’s ISA and verify that ISA theory is a valid tool to analyse segment rotation during the golf swing. Results indicate that for all subjects, at least 71% of marker velocity is a result of rotation about their respective ISA, when averaging results over the duration of the downswing, confirming that motion is primarily rotational. Furthermore, ISA position and orientation of each segment approaches, on average, the expected gross axis of rotation, confirming that motion about the ISA is representative of joint motion.     

低碳理念促进体育产业可持续发展的策略分析

低碳理念与低碳经济发展模式,作为减少二氧化碳排放、缓解全球变暖的重要理论与实践支持,成为企业绿色环保发展的重要指标。体育产业通过落实低碳理念,能够更好地促进经济的发展,提高体育产业升级的速度。本文在分析低碳理念对促进体育产业发展意义的基础上,对我国体育产业的发展现状进行了研究,最后提出了低碳经济理念下我国体育产业发展的策略。     

Measuring the Impact of State Accountability Programs

" No Child Left Behind is a law that makes good people bad and bad people worse."

Declaration of the keynote speaker at the public forum on the No Child Left Behind Act in Columbus, Ohio, on November 17, 2004, sponsored by the Kappa Delta Pi International Honor Society in Education, the National Academy of Education, and the National Society for the Study of Education.