Beginning literacy: links among teacher knowledge, teacher practice, and student learning

Although the importance of phonological awareness has been discussed widely in the research literature, the concept is not well understood by many classroom teachers. In the study described here, we worked with groups of kindergarten and first-grade teachers (the experimental group) during a 2-week summer institute and throughout the school year. We shared with them research about learning disabilities and effective instruction, stressing the importance of explicit instruction in phonological and orthographic awareness. We followed the experimental group and a control group into their classrooms for a year, assessing teachers' classroom practices and their students' (n = 779) learning. The study yielded three major findings: We can deepen teachers' own knowledge of the role of phonological and orthographic information in literacy instruction; teachers can use that knowledge to change classroom practice; and changes in teacher knowledge and classroom practice can improve student learning.     

Flow manipulation and cell immobilization for biochemical applications using thermally responsive fluids

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.     

The (Un)Common Instructor: A New Role for Medical Librarians Beyond Information Literacy

University common reading programs provide a shared experience as students transition into college life and develop critical thinking skills. Typically in such programs, all students in an incoming class read and discuss the same book. Conversely, the University of Florida Honors Program’s (un)common reads facilitates the same skills development through multiple small sections, each focusing on a different book and each with flexible and innovative assignments and activities. Health Science Center librarians have taught in these (un)common reads since the spring semester 2010–2011. This article describes librarian involvement in this program as well as the ensuing benefits for students, librarians, and the university at large.     

Organizational response to decline in the academic marketplace

In the last twenty-five years institutions of higher education and the academic market-place have undergone considerable change. A period of rapid growth and expansion was followed by a period of shrinking resources and decreasing growth. The effects of organizational decline on personnel management and on the formal structure of the academic hierarchy are examined in Israeli universities. The data show that in the non-growth period standards for faculty selection and advancement have not been formally altered, although actual practices have resulted in prolonged time periods between promotions and until tenure is obtained. The most salient change that has taken place is a continuous process of proliferation of the academic hierarchy by addition of new tracks and ranks to the main regular faculty track, and the increasing use of these positions particularly for new hires. This is consistent with other studies which found that organizational complexity may increase under conditions of decline. The effectiveness and functions of this process as an adaptive response to environmental scarcity are discussed.     

Blurred Boundaries or Conflicting Epistemologies

In this article, I discuss how information activists and journalists in Egypt claimed to acquire knowledge about the world, looking particularly at the period of 2012 and 2013, during which the Supreme Council of the Armed Forces and Mohammed Morsi in turn were leading the country. Taking a point of departure in anthropological fieldwork with information activists and journalists in Egypt, I show that information activists and journalists often had very similar practices and goals, which at times made the boundaries very blurry. Yet I argue that there was a significant distinction between the epistemologies of information activists and journalists. Information activists claimed to acquire knowledge about events from being part of them, whereas journalists claimed to acquire knowledge about events from observing them without taking part. Relatedly, information activists and journalists had significantly different relationships with their audiences.     

从学生评语的变迁透视学生评价实践中的话语裂缝现象

解释学认为,学生评语是在判断学生一个阶段的学习情况时,评价主体被赋予权力用以建构话语并以文本的形式对其进行解释的表达手段,是对学生全面成长状态化的质性评价。所以话语建构和文本解释是学生评语的核心,也是衡量学生评语有效性的基础。然而曾几何时,学生评语却陷入了“几家欢喜几家愁,想说爱你不容易”的尴尬境地。由此,本文针对学生评价中以学生评语为代表所呈现的话语裂缝现象进行相应的分析。     

不同阅读方式下学前儿童在图画书阅读中对文字的关注

分享阅读被认为可以有效提高儿童的文字意识,因为它可以使儿童获得更多与文字接触的机会。为了验证以上观点,本研究以SMI眼动仪为工具,对71名3~6岁幼儿在自主阅读和分享阅读方式下阅读图画书的特点进行考察。结果发现:分享阅读不能提高学前儿童对文字的关注程度,自读方式则可以增加儿童与文字接触的机会;儿童对文字的关注程度随着年龄班的增长而提高,且在小班与中班之间变化最为明显;阅读方式不影响儿童对主人公的关注程度;分享阅读提高了儿童信息加工的速度,且该效应在小班最明显;儿童对图画书中隐藏细节信息的关注程度随着年龄班的增长而降低。     

Paternal Sensitivity and Children’s Cognitive and Socioemotional Outcomes: A Meta-Analytic Review

In a series of meta-analyses, paternal sensitivity was associated with children’s (age range: 7 months–9 years) overall cognitive functioning (N = 3,193; k = 23; r = .19), including language skills (k = 9; r = .21), cognitive ability (k = 9; r = .18), and executive function (k = 8; r = .19). Paternal sensitivity was not associated with children’s overall socioemotional functioning (N = 2,924; k = 24; r = −.03) or internalizing problems, but it was associated with children’s emotion regulation (k = 7; r = .22) and externalizing problems (k = 19; r = −.08). In the broad cognitive functioning, executive function, broad socioemotional functioning, and externalizing problems meta-analyses, child age was a significant moderator.     

How (German) foundations shape the concept of education: Towards an understanding of their use of discourses

In this article I examine how foundations use the concept of education and how they try to shape its definition and implementation. In accordance with Steven Lukes’ notion, I argue that changes in social fields are mainly triggered by normative and semantic shifts. By drawing on techniques of discourse analysis, I explore the use of discursive strategies and the discursive interpretations of education, as both its definition and its operationalization have consequences on the identification of educational needs and outcomes. It is shown that foundations regard the use of education as an opportunity to influence values, traditions, and future generations. Furthermore, foundations take part in debates on education in order to increase social influence, to be accepted as legitimate actors in education, and to be perceived as competent and indispensable players in defining educational goals.