Life under flow: A novel microfluidic device for the assessment of anti-biofilm technologies     

Maria Salta  Lorenzo Capretto  Dario Carugo  Julian A. Wharton  Keith R. Stokes 《Biomicrofluidics》2013,7(6)

In the current study, we have developed and fabricated a novel lab-on-a-chip device for the investigation of biofilm responses, such as attachment kinetics and initial biofilm formation, to different hydrodynamic conditions. The microfluidic flow channels are designed using computational fluid dynamic simulations so as to have a pre-defined, homogeneous wall shear stress in the channels, ranging from 0.03 to 4.30 Pa, which are relevant to in-service conditions on a ship hull, as well as other man-made marine platforms. Temporal variations of biofilm formation in the microfluidic device were assessed using time-lapse microscopy, nucleic acid staining, and confocal laser scanning microscopy (CLSM). Differences in attachment kinetics were observed with increasing shear stress, i.e., with increasing shear stress there appeared to be a delay in bacterial attachment, i.e., at 55, 120, 150, and 155 min for 0.03, 0.60, 2.15, and 4.30 Pa, respectively. CLSM confirmed marked variations in colony architecture, i.e.,: (i) lower shear stresses resulted in biofilms with distinctive morphologies mainly characterised by mushroom-like structures, interstitial channels, and internal voids, and (ii) for the higher shear stresses compact clusters with large interspaces between them were formed. The key advantage of the developed microfluidic device is the combination of three architectural features in one device, i.e., an open-system design, channel replication, and multiple fully developed shear stresses.  相似文献   

The association between mathematics pedagogy and learners’ dispositions for university study     

Maria Pampaka  Julian Williams  Graeme Hutcheson  Geoff Wake  Laura Black  Pauline Davis  Paul Hernandez‐Martinez 《British Educational Research Journal》2012,38(3):473-496

We address the current concerns about teaching‐to‐the‐test and its association with declining dispositions towards further study of mathematics and the consequences for choice of STEM subjects at university. In particular, through a mixed study including a large survey sample of over 1000 students and their teachers, and focussed qualitative case studies, we explored the impact of ‘transmissionist’ pedagogic practices on learning outcomes. We report on the construction and validation of a scale to measure teachers’ self‐reported pedagogy. We then use this measure in combination with the students’ survey data and through regression modelling we illustrate significant associations between the pedagogic measure and students’ mathematics dispositions. Finally, we discuss the potential implications of these results for mathematics education and the STEM agenda.  相似文献   

Reimagining liberal education: affiliation and inquiry in democratic schooling     

Julian Stern 《British Journal of Religious Education》2016,38(1):99-101

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Conditioned suppression of a positively reinforced shuttle response     

Julian C. Leslie  Paul Garrud 《Learning & behavior》1976,4(1):99-104

Rats were trained to run up and down an alleyway for sucrose reinforcement on a variable interval schedule. Differential aversive classical conditioning with auditory CSs was then conducted in a separate apparatus (“off the baseline”) prior to those CSs being presented while the subjects were responding for sucrose in the alleyway. Once the effects of the CSs had extinguished, shock was reintroduced following one CS but not the other (“on the baseline” differential aversive classical conditioning). Both “off the baseline” and “on the baseline” conditioning resulted in conditioned suppression to the CS followed by shock, but little effect of the CS followed by no shock was found. In the “on the baseline” phase, total suppression of baseline responding occurred at moderate US intensities, and this appeared to result from the subject avoiding the location at which he was last shocked. At lower values, both baseline response rate and relative suppression ratio were functions of US intensity. The results are discussed in relation to the effects found in similar experiments using avoidance baselines.  相似文献   

Conceptions of the Curriculum: teachers and ‘truth‘     

Julian Haes 《British Journal of Sociology of Education》1982,3(1):57-76

This article draws its inspiration from the three socio‐epistemological theories of phenomenology, contextualism and traditional epistemology and their abrasive interrelation. From these foundations, a theoretical framework is devised as a basis for an exposition and interpretation of empirical work undertaken in four contrasting school contexts. The aim of the research was firstly to look for similarities between teachers’ conceptions of the curriculum and secondly to provide evidence which could be used as a basis for judging to what extent these similarities were constrained by teachers’ conceptions of ‘truth’.

The paper discusses teachers’ responses to three questions from an open‐ended questionnaire; these requested views on how far curriculum content was considered to be related: (a) to individual pupils, (b) to social requirements and (c) to ‘truth’. The discussion of each question resolves itself into a number of issues connected with these three themes.

The article is predominantly interpretative but a short appendix displays a more rigorous analysis of the distribution of the responses across the four schools. Finally, although the paper is concerned with opinions about curricula rather than with actual curricula transactions, my hope is that awareness of teachers’ ideas may provide indicators for curricular realities.  相似文献   

Evaluating the validity of the Automated Working Memory Assessment     

Tracy P. Alloway  Susan E. Gathercole  Hannah Kirkwood  Julian Elliott 《教育心理学》2008,28(7):725-734

The aim of the present study was to investigate the construct stability and diagnostic validity of a standardised computerised tool for assessing working memory: the Automated Working Memory Assessment (AWMA). The purpose of the AWMA is to provide educators with a quick and effective tool to screen for and support those with memory impairments. Findings indicate that working memory skills in children with memory impairments are relatively stable over the course of the school year. There was also a high degree of convergence in performance between the AWMA and the WISC‐IV Working Memory Index. The educational implications are discussed.  相似文献   

Freedom of information in the U.K.: a progress report     

Patrick J. Birkinshaw   《Government Information Quarterly》2000,17(4):419

Last year the author wrote about the U.K.’s plans to embrace Freedom of Information (FOI) legislation after a quarter of a century of campaigns for such legislation by the Labor Party. The Bill has now been presented to Parliament and has been amended by government to meet some objections. It is still widely criticized, however. The FOI Bill is also one of several measures that relate to openness in contemporary aspects of British government.  相似文献   

Calibration and Scoring of Tests With Multiple-Choice and Constructed-Response Item Types     

Kadriye Ercikan  Richard D. Sehwarz  Marc W. Julian  George R. Burket  Melba M. Weber  Valerie Link 《Journal of Educational Measurement》1998,35(2):137-154

This article discusses and demonstrates combining scores from multiple-choice (MC) and constructed-response (CR) items to create a common scale using item response theory methodology. Two specific issues addressed are (a) whether MC and CR items can be calibrated together and (b) whether simultaneous calibration of the two item types leads to loss of information. Procedures are discussed and empirical results are provided using a set of tests in the areas of reading, language, mathematics, and science in three grades.  相似文献