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91.
Christopher R. Phaneuf Nikita Pak D. Curtis Saunders Gregory L. Holst Joav Birjiniuk Nikita Nagpal Stephen Culpepper Emily Popler Andi L. Shane Robert Jerris Craig R. Forest 《Biomicrofluidics》2015,9(4)
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. 相似文献
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The use of structural equation modeling (SEM) in communication research has become increasingly popular in recent years, with SEM being commonly used as the primary method of data analysis in studies published within the field’s journals. However, despite its widespread use, there are persistent misapplications of SEM in published empirical studies in the communication sciences. Of these types of misuse, the most troubling are those related to the exploitation of flexibilities in data collection and analysis. Given the number of decisions that must be made when analyzing and reporting structural equation models, decisions which often remain undisclosed, the potential for researchers to exploit flexibilities in SEM research is high. To assess the extent of this problem, as well as the more longstanding types of misuse (i.e., omission of information and disclosed “bad practice”) identified by prior studies, we undertake a methodical review of studies employing structural equation modeling within major journals in the field of communication between the years 2007 and 2011. Articles were coded on the characteristics of the sample, characteristics of the model tested, as well as for various potential problems that we defined a priori. The most serious issues are identified, and recommendations for future standards in SEM research are suggested. 相似文献
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Christopher Winch 《Journal of Philosophy of Education》2015,49(4):539-556
This article will consider the claim that the possession of concepts is innate rather than learned. Innatism about concept learning is explained through consideration of the work of Fodor and Chomsky. First, an account of concept formation is developed. Second the argument against the claim that concepts are learned through the construction of a learning paradox developed by Fodor is considered. It is argued that, despite initial plausibility, the learning paradox is not, in fact, a paradox at all as it rests on eliding the distinction between recognising something and recognising it as a something. The plausibility of eliding this distinction rests, in turn, on begging the question as to whether concept possession is a necessary condition for recognition of objects, events, properties etc. Fodor's positive arguments for innatism, as set out in LOT2 are considered and parallels with his account of stereotype formation and associationist accounts of concept formation are considered. The explanatory persuasiveness of this revised account of concept activation through the generation of stereotypes is weak. The article then examines the distinction between concept possession and concept mastery in greater detail, arguing that innatists have difficulty in accounting for the phenomenon of concept mastery, including within the contexts of formal and professional education. 相似文献
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Christopher Hamlin 《Science & Education》2017,26(1-2):191-193
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Zoe Rutherford Brendan Gough Sarah Seymour-Smith Christopher R Matthews John Wilcox Dan Parnell 《Soccer & Society》2014,15(6):951-969
The purpose of this study was to examine whether an innovative, inclusive and integrated 12-week exercise, behaviour change and nutrition advice-based weight management programme could significantly improve the cardiovascular risk factors of overweight and obese men and women over the age of 35. One hundred and ninety-four men and 98 women (mean age?=?52.28?±?9.74 and 51.19?±?9.04) attending a community-based intervention delivered by Notts County Football in the Community over one year, took part in the study. Height (m), weight (kg), fitness (meters covered during a 6?min walk) and waist circumference (cm) were measured at weeks 1 and 12 as part of the intervention. Changes in body weight, waist circumference and fitness for men and women were measured by a 2-way repeated measures ANOVA, with significance set to p?<?0.05.Weight, waist circumference and fitness significantly improved over time in both men (4.96?kg, 6.29?cm, 70.22?m; p?<?0.05) and women (4.26?kg, 5.90?cm, 35.29?m; p?<?0.05). The results demonstrated that the FITC lead weight loss intervention was successful in significantly improving cardiovascular risk factors in both men and women. In particular, the weight loss reductions achieved were comparable to those seen in similar, more costly men-only programmes. This is the first study to demonstrate the efficacy of such an intervention in an inclusive, mixed gender programme and more specifically, in women. 相似文献
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