Modeling and validation of autoinducer-mediated bacterial gene expression in microfluidic environments     

Caitlin M. Austin  William Stoy  Peter Su  Marie C. Harber  J. Patrick Bardill  Brian K. Hammer  Craig R. Forest 《Biomicrofluidics》2014,8(3)

Biosensors exploiting communication within genetically engineered bacteria are becoming increasingly important for monitoring environmental changes. Currently, there are a variety of mathematical models for understanding and predicting how genetically engineered bacteria respond to molecular stimuli in these environments, but as sensors have miniaturized towards microfluidics and are subjected to complex time-varying inputs, the shortcomings of these models have become apparent. The effects of microfluidic environments such as low oxygen concentration, increased biofilm encapsulation, diffusion limited molecular distribution, and higher population densities strongly affect rate constants for gene expression not accounted for in previous models. We report a mathematical model that accurately predicts the biological response of the autoinducer N-acyl homoserine lactone-mediated green fluorescent protein expression in reporter bacteria in microfluidic environments by accommodating these rate constants. This generalized mass action model considers a chain of biomolecular events from input autoinducer chemical to fluorescent protein expression through a series of six chemical species. We have validated this model against experimental data from our own apparatus as well as prior published experimental results. Results indicate accurate prediction of dynamics (e.g., 14% peak time error from a pulse input) and with reduced mean-squared error with pulse or step inputs for a range of concentrations (10 μM–30 μM). This model can help advance the design of genetically engineered bacteria sensors and molecular communication devices.  相似文献   

Further Validation of the Coach Identity Prominence Scale     

J. Paige Pope  Craig R. Hall 《Measurement in physical education and exercise science》2014,18(4):286-298

This study was designed to examine select psychometric properties of the Coach Identity Prominence Scale (CIPS), including the reliability, factorial validity, convergent validity, discriminant validity, and predictive validity. Coaches (N = 338) who averaged 37 (SD = 12.27) years of age, had a mean of 13 (SD = 9.90) years of coaching experience, and were currently coaching 46 different sports, served as the participants in this study. Participants completed a questionnaire that included four sections: Demographics, identity prominence (CIPS; Pope & Hall, 2014), motivation (Coach Motivation Questionnaire [CMQ]; McLean, Mallet, & Newcombe, 2012), and passion (The Passion Scale; Vallerand et al., 2003). The findings provided support for the various types of reliability and validity tested in the present study, with only partial support for discriminant validity. The CIPS may therefore serve as a viable option for researchers interested in further understanding the identity or psychological processes of coach.  相似文献   

Using VoiceThread to Create Meaningful Receptive and Expressive Learning Activities for Young Children     

Afton Gillis  Katie Luthin  Howard P. Parette  Craig Blum 《Early Childhood Education Journal》2012,40(4):203-211

Development of receptive and expressive language skills is an important foundational skill in early childhood education. Recently, early childhood education professionals have begun using Web-based technology to assist in developing these skills. One Web-based technology that holds potential to support children’s learning is VoiceThread which has unique features that support Universal Design for Learning. This paper provides practical recommendations for use of VoiceThread in meaningful learning activities that can easily be implemented. A step-by-step guide is presented to create and use VoiceThread.  相似文献   

Why Media Matter     

Craig Locatis 《Performance Improvement Quarterly》2007,20(1):9-22

Whether media affect learning has been debated for decades. The discussion of media's effectiveness has raised questions about the usefulness of comparison studies, not only in assessing applications of technology but in other areas as well. Arguments that media do not affect learning are re‐examined and issues concerning media effects on expert performance are examined. Studies of mediated expert performance in telemedicine are used to show media affect performance and suggest media contribute to learning. Media present information crucial to performing certain tasks and the use of identical or similar media in learning these tasks should have positive effects on transfer. The usefulness of media comparison studies in telemedicine is discussed and it is argued that such studies are valuable for practical decision making regarding the deployment and application of technology in training and the workplace.  相似文献   

The Use of Epidemiological Methodology as a Means of Influencing Public Policy   总被引：1，自引：0，他引：1  

Keith G. Scott  Craig A. Mason  & Derek A. Chapman 《Child development》1999,70(5):1263-1272

To best influence policymakers, researchers need to provide information and measures of effects that reflect the nature of policy decisions. Specifically, policymakers are often interested in factors associated with changes in the number of cases or rate of disorders in a community. Regression/analysis of variance (ANOVA) models, which focus on the prediction of means, slopes, and variances, do not directly address such questions. In contrast, epidemiological statistics, which focus on differences in proportions of cases, do provide such information. Three epidemiological measures of effect (the risk-ratio, the odds-ratio, and the population attributable fraction) are reviewed; their value as tools for informing public policy is discussed; and examples are provided illustrating their use. Researchers are encouraged to consider adopting an epidemiological perspective as part of their work.  相似文献   

Reviews     

John Hedley Brooke  Terry Dartnall  Celia Roberts  Sally Newcomb  Rafe Champion  Andrew Milne  Martin Kelly  Wendy Varney  Orin Thomas  Craig R. Stillwell  Leonard G. Wilson  Peter Anstey  Jay L. Garfield  Mark Colyvan  Mark Cortiula  John Merson  Nicolas Rasmussen  Nickolas Vakas  John Forge  Sunny Y. Auyang  Clair Scrine  Katharina Rowold 《Metascience》1999,8(3):444-514

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A Step Beyond Univision Evaluations Using a Systems Model of Performance Improvement     

Catherine M. Sleezer  Jiping Zhang  Deane B. Gradous  Craig Maile 《Performance Improvement Quarterly》1999,12(3):119-131

The article examines three views of performance improvement-scientific management, instructional design, and systems thinking, Each provides a unique view of performance improvement and specific roles for evaluation. Envisioning performance improvement from a single view may be insufficient for evaluating the performance improvement situations found in today's dynamic organisations. The articie provides an integrated definition of performance and a synthesis, model, the Systems Model of Performance.  相似文献   

Surface patterning of bonded microfluidic channels   总被引：1，自引：0，他引：1  

Priest C 《Biomicrofluidics》2010,4(3):32206

Microfluidic channels in which multiple chemical and biological processes can be integrated into a single chip have provided a suitable platform for high throughput screening, chemical synthesis, detection, and alike. These microchips generally exhibit a homogeneous surface chemistry, which limits their functionality. Localized surface modification of microchannels can be challenging due to the nonplanar geometries involved. However, chip bonding remains the main hurdle, with many methods involving thermal or plasma treatment that, in most cases, neutralizes the desired chemical functionality. Postbonding modification of microchannels is subject to many limitations, some of which have been recently overcome. Novel techniques include solution-based modification using laminar or capillary flow, while conventional techniques such as photolithography remain popular. Nonetheless, new methods, including localized microplasma treatment, are emerging as effective postbonding alternatives. This Review focuses on postbonding methods for surface patterning of microchannels.  相似文献   

Preschoolers modulate contrastive inferences during online language comprehension     

Narae Ju  Natalie Williams  Julie Sedivy  Craig G. Chambers  Susan A. Graham 《Child development》2023,94(5):1319-1329

This study examined 4- and 5-year-olds' incremental interpretation of size adjectives, focusing on whether contrastive inferences are modulated by speaker behavior. Children (N = 120, 59 females, mostly White, tested between July, 2018 and August, 2019) encountered either a conventional or unconventional speaker who labeled objects in a correspondingly typical or atypical way. Critical utterances contained size adjectives (e.g., “Look at the big duck”). With conventional speakers, gaze measures indicated that children rapidly used the adjective to differentiate members of a contrasting pair, indicating that even 4-year-olds derive contrastive inferences. With unconventional speakers, contrastive inferences were delayed in processing. The findings demonstrate that preschoolers adjust their use of pragmatic cues when presented with evidence disconfirming their default assumptions about a speaker.  相似文献   

Using the Concrete-Representational-Abstract Sequence to Teach Conceptual Understanding of Place Value,Rounding, and Expanded Notation     

Jessica H. Milton  Margaret M. Flores  Vanessa M. Hinton  Caroline Dunn  Craig B. Darch 《Learning disabilities research & practice》2023,38(1):15-25

This study investigated the effects of a place value intervention with third-grade students with learning disabilities. The intervention added content to a research-based intervention using the concrete-representational-abstract (CRA) sequence. The added content reflected current mathematics standards for third grade. Students’ place value understanding was measured using probes in which students had to identify the value of each digit within a three-digit number, round three-digit numbers to the nearest 10 or 100, and write three equations showing an expanded form of a three-digit number. A single-case, multiple-probe-across-students design showed a functional relation between CRA and completion of items requiring place value understanding. Students completed a generalization task by estimating the sum of a given equation.  相似文献