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31.
32.
An initiative in which therapy dogs were integrated into a school-wide reading curriculum was analyzed to determine the effect on student reading in the program’s second year. Prior research on the first year of this specific program (Kirnan et al. in Early Child Educ J 44(6):637–651) demonstrated improvement in reading scores only for kindergarten students, while interview data revealed increases in positive attitudes and enthusiasm for reading across all grades. In the current study, a series of independent t-tests were conducted for each grade, comparing the second year of the program to a control group. There was a significant difference for kindergarten in the second year, as reading scores were higher for program students compared to those in the control group. Unlike the first year of the program, in the second year there was also a significant mean difference in first grade. For both grades, an analysis of covariance controlling for reading scores prior to program implementation still resulted in a significant main effect for the reading program. Combining the first 2 years of the program yielded a large enough sample for a comparison of ELL students with non-ELL students in kindergarten. These data showed significantly higher reading scores for students enrolled in the dog program relative to the control for both ELL and non-ELL students, again accounting for earlier reading scores. These findings demonstrate the need to analyze at-risk subgroups as well as the need to apply a longitudinal lens in researching both dog-assisted literacy programs and participant progress. 相似文献
33.
Tobias Kärner Nina Minkley Andreas Rausch Thomas Schley Detlef Sembill 《Vocations and Learning》2018,11(3):365-398
By adapting the job demands-resources model of Demerouti et al. Journal of Applied Psychology, 86(3), 499–512, (2001) to vocational problem-solving situations, we aimed to investigate how, and to what extent, problem-solving demands and personal resources affect stress responses and task interest. Therefore, we used a problem-solving task from the business administration domain in a computer-based office simulation. We assigned 58 participants into two groups. The treatment group worked on the problem scenario, whereas the control group was instructed to inspect the computer-based scenario and to check the software’s usability without solving the problem. Problem-solving demands, perceived stress, task interest, cardiovascular parameters, and cortisol concentration were assessed before, during and after the task at several time points. The vocational problem-solving task was associated with perceived time pressure, uncertainty, mental effort, task difficulty, and perceived stress. In addition, we found higher heart rate and cortisol concentration and lower heart rate variability values in the treatment group (compared to the control group) at the end of the task. Furthermore, we found that content knowledge buffers the impact of problem-solving demands on stress responses and it maintains task interest under high mental effort. Overall, we found evidence that vocational problem-solving activities bear stress-evoking potential and personal resources may provide buffering and maintaining functions. 相似文献
34.
This article focuses on vocational learning in technical vocational education in upper-secondary school, with a special focus on the object of learning to weld. A concrete teaching situation where the learning object to weld is the focus of the interaction between a vocational teacher and an upper-secondary student was documented by a video camera and then analysed from two different perspectives: a conversation analytical perspective and a variation theory perspective. The combination of the two perspectives allows a study of learning that deals with issues regarding both form and content, which may increase our understanding of vocational learning in technical vocational education in upper-secondary school. 相似文献
35.
Nina Daskalovska 《The Journal of educational research》2016,109(1):68-80
A number of studies have shown that second or foreign language learners can acquire vocabulary through reading. The aim of the study was to investigate (a) the effects of reading an authentic novel on the acquisition of 3 aspects of word knowledge: spelling, meaning, and collocation; (b) the influence of reading on the acquisition of partial and deeper knowledge of the words; and (c) the relationship between word frequency and learning gains. The results show that there was significant improvement in all three aspects of word knowledge. The measuring instrument detected greater partial than deeper knowledge gains in word meanings and collocations. The greatest learning gains in all three aspects of word knowledge were demonstrated for the words that occurred between 11 and 20 times in the text. The findings suggest that incorporation of extensive reading into language learning programs can contribute to significant improvement of learners' vocabulary knowledge. 相似文献
36.
37.
Margareta Sandström Nina Klang Gunilla Lindqvist 《Scandinavian Journal of Educational Research》2019,63(1):89-104
In Sweden, policy changes for provision of special support have been introduced, implying that teachers are obliged to provide and evaluate extra adaptations in regular classrooms prior to referring pupils to special support. The policy changes raise questions about school staffs’ views of support measures and of necessary professional competence for provision of the support measures. We conducted focus group interviews with 60 school staff representatives—headmasters, general education teachers, and special educators/school welfare teams—about their understandings of the new policy. The data were analyzed qualitatively, with the objective to explore school staffs’ approaches to the policy changes. Two main “ideal type approaches” were discerned, using Skrtic’s theories, viz. the bureaucracy approach and adhocracy approach. In the light of Skrtic’s theory, professionals’ reasoning about the new policy may reflect difficulties that are encountered in the process of implementing the policy in bureaucracy-steered schools. 相似文献
38.
Filippo Abbondanza Philip S. Dale Carol A. Wang Marianna E. Hayiou-Thomas Umar Toseeb Tanner S. Koomar Karen G. Wigg Yu Feng Kaitlyn M. Price Elizabeth N. Kerr Sharon L. Guger Maureen W. Lovett Lisa J. Strug Elsje van Bergen Conor V. Dolan J. Bruce Tomblin Kristina Moll Gerd Schulte-Körne Nina Neuhoff Andreas Warnke Simon E. Fisher Cathy L. Barr Jacob J. Michaelson Dorret I. Boomsma Margaret J. Snowling Charles Hulme Andrew J. O. Whitehouse Craig E. Pennell Dianne F. Newbury John Stein Joel B. Talcott Dorothy V. M. Bishop Silvia Paracchini 《Child development》2023,94(4):970-984
Handedness has been studied for association with language-related disorders because of its link with language hemispheric dominance. No clear pattern has emerged, possibly because of small samples, publication bias, and heterogeneous criteria across studies. Non-right-handedness (NRH) frequency was assessed in N = 2503 cases with reading and/or language impairment and N = 4316 sex-matched controls identified from 10 distinct cohorts (age range 6–19 years old; European ethnicity) using a priori set criteria. A meta-analysis (Ncases = 1994) showed elevated NRH % in individuals with language/reading impairment compared with controls (OR = 1.21, CI = 1.06–1.39, p = .01). The association between reading/language impairments and NRH could result from shared pathways underlying brain lateralization, handedness, and cognitive functions. 相似文献
39.
Anil Haraksingh Thilsted Vahid Bazargan Nina Piggott Vivien Measday Boris Stoeber 《Biomicrofluidics》2012,6(4)
A flow redirection and single cell immobilization method in a microfluidic chip is presented. Microheaters generated localized heating and induced poly(N-isopropylacrylamide) phase transition, creating a hydrogel that blocked a channel or immobilized a single cell. The heaters were activated in sets to redirect flow and exchange the fluid in which an immobilized cell was immersed. A yeast cell was immobilized in hydrogel and a 4′,6-diamidino-2-phenylindole (DAPI) fluorescent stain was introduced using flow redirection. DAPI diffused through the hydrogel and fluorescently labelled the yeast DNA, demonstrating in situ single cell biochemistry by means of immobilization and fluid exchange.The ability to control microfluidic flow is central to nearly all lab-on-a-chip processes. Recent developments in microfluidics either include microchannel based flow control in which microvalves are used to control the passage of fluid,1 or are based on discrete droplet translocation in which electric fields or thermal gradients are used to determine the droplet path.2, 3 Reconfigurable microfluidic systems have certain advantages, including the ability to adapt downstream fluid processes such as sorting to upstream conditions and events. This is especially relevant for work with individual biomolecules and high throughput cell sorting.4 Additionally, reconfigurable microfluidic systems allow for rerouting flows around defective areas for high device yield or lifetime and for increasing the device versatility as a single chip design can have a variety of applications.Microvalves often form the basis of flow control systems and use magnetic, electric, piezoelectric, and pneumatic actuation methods.5 Many of these designs require complicated fabrication steps and can have large complex structures that limit the scalability or feasability of complex microfluidic systems. Recent work has shown how phase transition of stimuli-responsive hydrogels can be used to actuate a simple valve design.6 Beebe et al. demonstrated pH actuated hydrogel valves.7 Phase transition of thermosensitive poly(N-isopropylacrylamide) (PNIPAAm) using a heater element was demonstrated by Richter et al.8 Phase transition was also achieved by using light actuation by Chen et al.9 Electric heating has shown a microflow response time of less than 33 ms.11 Previous work10 showed the use of microheaters to induce a significant shift in the viscosity of thermosensitive hydrogel to block microchannel flow and deflect a membrane, stopping flow in another microchannel. Additionally, Yu et al.12 demonstrated thermally actuated valves based on porous polymer monoliths with PNIPAAm. Krishnan and Erickson13 showed how reconfigurable optically actuated hydrogel formation can be used to dynamically create highly viscous areas and thus redirect flow with a response time of ~ 2?s. This process can be used to embed individual biomolecules in hydrogel and suppress diffusion as also demonstrated by others.15, 16 Fiddes et al.14 demonstrated the use of hydrogels to transport immobilized biomolecules in a digital microfluidic system. While the design of Krishnan and Erickson is highly flexible, it requires the use of an optical system and absorption layer to generate a geometric pattern to redirect flow.This paper describes the use of an array of gold microheaters positioned in a single layer polydimethylsiloxane (PDMS) microfluidic network to dynamically control microchannel flow of PNIPAAm solution. Heat generation and thus PNIPAAm phase transition were localized as the microheaters were actuated using pulse width modulation (PWM) of an applied electric potential. Additionally, hydrogel was used to embed and immobilise individual cells, exchange the fluid parts of the microfluidic system in order to expose the cells to particular reagents to carry out an in situ biochemical process. The PDMS microchannel network and the microheater array are shown in Figure Figure11.Open in a separate windowFigure 1A sketch of the electrical circuit and a microscope image of the gold microheaters and the PDMS microchannels. The power to the heaters was modulated with a PWM input through a H-bridge. For clarity, the electrical circuit for only the two heaters with gelled PNIPAAm is shown (H1 and V2). There are four heaters (V1-V4) in the “vertical channels” and three heaters (H1-H3) in the “horizontal” channel.The microchannels were fabricated using a patterned mould on a silicon wafer to define PDMS microchannels, as described by DeBusschere et al.17 and based on previous work.10 A 25 × 75 mm glass microscope slide served as the remaining wall of the microchannel system as well as the substrate for the microheater array. The gold layer had a thickness of 200 nm and was deposited and patterned using E-beam evaporation and photoresist lift-off.21 The gold was patterned to function as connecting electrical conductors as well as the microheaters.It was crucial that the microheater array was aligned with an accuracy of ~ 20μm with the PDMS microchannel network for good heat localization. The PDMS and glass lid were treated with plasma to activate the surface and alignment was carried out by mounting the microscope slide onto the condenser lens of an inverted microscope (TE-2000 Nikon Instruments). While imaging with a 4× objective, the x, y motorized stage aligned the microchannels to the heaters and the condenser lens was lowered for the glass substrate to contact the PDMS and seal the microchannels.Local phase transition of 10% w/w PNIPAAm solution in the microchannels was achieved by applying a 7 V potential through a H-bridge that received a PWM input at 500 Hz which was modulated using a USB controller (Arduino Mega 2650) and a matlab (Mathworks) GUI. The duty cycle of the PWM input was calibrated for each microheater to account for differences in heater resistances (25?Ω to 52?Ω) due to varying lengths of on-chip connections and slight fabrication inconsistencies, as well as for different flow conditions during device operation. Additionally, thermal cross-talk between heaters required decreasing the PWM input significantly when multiple heaters were activated simultaneously. This allowed confining the areas of cross-linked PNIPAAm to the microheaters, allowing the fluid in other areas to flow freely.By activating the heaters in sets, it was possible to redirect the flow and exchange the fluid in the central area. Figure Figure22 demonstrates how the flow direction in the central microchannel area was changed from a stable horizontal flow to a stable vertical flow with a 3 s response time, using only PNIPAAm phase transition. Constant pressures were applied to the inlets to the horizontal channel and to the vertical channels. Activating heaters V1-4 (Figure (Figure2,2, left) resulted in flow in the horizontal channel only. Likewise, activating heaters H1 and H2 allowed for flow in the vertical channel only. In this sequence, the fluid in the central microchannel area from one inlet was exchanged with fluid from the other inlet. Additionally, by activating heater H3, a particle could be immobilised during the exchange of fluid as shown in Figure Figure33 (top).Open in a separate windowFigure 2Switching between fluid from the horizontal and the vertical channel using hydrogel activation and flow redirection with a response time of 3 s. A pressure of 25 mbar was applied to the inlet of the horizontal channel and a pressure of 20 mbar to the vertical channel. The flow field was determined using particle image velocimetry, in which the displacement of fluorescent seed particles was determined from image pairs generated by laser pulse exposure. Processing was carried out with davis software (LaVision).Open in a separate windowFigure 3A series of microscope images near heater H3 showing: (1a)-(1c) A single yeast cell captured by local PNIPAAm phase transition and immobilized for 5 min before being released. (2a) A single yeast cell was identified for capture by embedding in hydrogel. (2b) The cell as well as the hydrogel displayed fluorescence while embedded due to the introduction of DAPI in the surrounding region. (2c) The diffusion of DAPI towards the cell as the heating power of H3 is reduced after 15 min, showing a DAPI stained yeast cell immobilized.Particle immobilisation in hydrogel and fluid exchange in the central area of the microfluidic network were used to carry out an in situ biochemical process in which a yeast cell injected through one inlet was stained in situ with a 4′,6-diamidino-2-phenylindole (DAPI) solution (Invitrogen), which attached to the DNA of the yeast cell.18 A solution of yeast cells with a concentration of 5 × 107cells/ml suspended in a 10% w/w PNIPAAm solution was injected through the horizontal channel. A solution of 2μg/l DAPI in a 10% w/w PNIPAAm solution was injected through the vertical channel. A single yeast cell was identified and captured near the central heater, and by deactivating the heaters in the vertical channel, DAPI solution was introduced in the microchannels around the hydrogel. After immobilising the cell for 15 min, the heater was deactivated, releasing the cell in the DAPI solution. This process is shown in Figure Figure33 (bottom). The sequence of the heater activation and deactivation in order to immobilize the cell and exchange the fluid is outlined in the supplementary material.21Eriksen et al.15 demonstrated the diffusion of protease K in the porous hydrogel matrix,19 and it was therefore expected that DAPI fluorescent stain (molecular weight of 350 kDa, Ref. 20) would also diffuse. DAPI diffusion is shown in Figure 3(2b) in which the yeast cell shows fluorescence while embedded in the hydrogel. The yeast cell was released by deactivating the central heater and activating all the others to suppress unwanted flow in the microchannel. As a result, the single cell was fully immersed in the DAPI solution. Immobilization of a single cell allows for selection of a cell that exhibits a certain trait and introduction of a new fluid while maintaining the cell position in the field of view of the microscope such that a biochemical response can be imaged continuously.In summary, a microfluidic chip capable of local heating was used to induce phase transition of PNIPAAm to hydrogel, blocking microchannel flow, and thereby allowing for reconfigurable flow. Additionally, the hydrogel was used to embed and immobilise a single yeast cell. DAPI fluorescent stain was introduced using flow redirection, and it stained the immobilized cell, showing diffusion into the hydrogel. The versatile design of this microfluidic chip permits flow redirection, and is suitable to carry out in situ biochemical reactions on individual cells, demonstrating the potential of this technology for forming large-scale reconfigurable microfluidic networks for biochemical applications. 相似文献
40.
League tables that rank universities may use reputational measures, performance measures, or both. Each type of measure has
strengths and weaknesses. In this paper, we rank disciplines in Australian universities both by reputation, using an international
survey of senior academics, and with actual performance measures. We then compare the two types of measures to see how closely
they match. The criterion we use for both sets of measures is ‘international academic standing’. We find a high correlation
between the survey results and the various measures of research performance. We also find a correlation between the quality
of student intake and the survey rankings, but the satisfaction levels of recent graduates do not correlate well with the
rankings by academics. We then construct an overall measure of performance, which gives very similar rankings to the survey
results, especially for the top-ranked institutions.
相似文献
Ross WilliamsEmail: |