Concurrent validity of the early screening profiles and the differential ability scales with an at‐risk preschool sample

The relationship between the Early Screening Profiles (ESP; Harrison, 1990) and the Differential Ability Scales (DAS; Elliott, 1990a) was studied. The participants were 94 (57 males, 37 females) at‐risk preschoolers ranging in age from 3 years 6 months to 5 years 11 months (M= 4 years 7 months; SD= 6.3 months). The sample included 72 Caucasians, 21 African Americans, and one Hispanic. This study found that the DAS GCA (General Conceptual Ability) mean score was significantly lower than the ESP Total Screening mean score. However, a strong relationship (r= .78) was found between the ESP Total Screening and DAS GCA scores, indicating that the ESP is a good predictor of cognitive ability among at‐risk preschoolers. © 2000 John Wiley & Sons, Inc.     

Onset of channeling during DNA electrophoresis in a sparse ordered post array

The “channeling hypothesis” of DNA electrophoresis in sparse, ordered arrays of posts predicts that the DNA will move through the array relatively unhindered if (i) the spacing between the posts is larger than the DNA coil and (ii) the electric field lines are straight. We tested this hypothesis by studying the electrophoretic separation of a small plasmid DNA (pUC19, 2686 base pairs) and a large, linear DNA (λ-DNA, 48 500 base pairs) in a hexagonal array of 1 μm diameter posts with a pitch of 7 μm. At low electric field strengths, these DNAs are separated due to the long-lived, rope-over-pulley collisions of λ-DNA with the posts. The resolution is lost as the electric field increases due to the onset of channeling by the λ-DNA. Using a diffusive model, we show that channeling arises at low electric fields due to the finite size of the array. This channeling is not intrinsic to the system and is attenuated by increasing the size of the array. Higher electric fields lead to intrinsic channeling, which is attributed to the disparate time scales for a rope-over-pulley collision and transverse diffusion between collisions. The onset of channeling is a gradual process, in agreement with extant Brownian dynamics simulation data. Even at weak electric fields, the electrophoretic mobility of λ-DNA in the array is considerably higher than would be expected if the DNA frequently collided with the posts.     

Innovators and innovated: Newspapers and the postdigital future beyond the “death of print”

Along with other cultural organizations, newspapers, through waves of digital disruption, have become subject to a dominant narrative of crisis. But newspapers have long participated in change. A constructivist approach, qualified by consideration of media materiality, draws attention to diverse but essential processes of innovation around them. We see a contraflow of migration from digital to print, opening up a shared media space; bonding strategies are bringing multimedia to ink on paper, while bridging via boundary objects such as QR (Quick Response) codes are connecting the two. Among other initiatives, development of automation of news production and experiments with transparency are further evidence of an active embrace of change by newspapers that calls into question the discourse on their demise. This analysis inductively develops a nuanced account of the role of the newspaper as an object and as an institution. It suggests a hybrid, multifaceted, enduring presence of print in the complex media ecology of the future.     

Bridge pressure flow scour at clear water threshold condition

Bridge pressure flow scour at clear water threshold condition is studied theoretically and experimentally. The flume experiments reveal that the measured scour profiles under a bridge are more or less 2-dimensional; all the measured scour profiles can be described by two similarity equations, where the horizontal distance is scaled by the deck width while the local scour by the maximum scour depth; the maximum scour position is located just under the bridge about 15% deck width from the downstream deck edge; the scour begins at about one deck width upstream the bridge while the deposition occurs at about 2.5 deck widths downstream the bridge; and the maximum scour depth decreases with increas-ing sediment size, but increases with deck inundation. The theoretical analysis shows that: bridge scour can be divided into three cases, i.e. downstream unsubmerged, partially submerged, and totally submerged. For downstream unsubmerged flows, the maximum bridge scour depth is an open-channel problem where the conventional methods in terms of critical velocity or bed shear stress can be applied; for partially and totally submerged flows, the equilibrium maximum scour depth can be described by a scour and an inundation similarity number, which has been confirmed by experiments with two decks and two sediment sizes. For application, a design and field evaluation procedure with examples is presented, including the maximum scour depth and scour profile.     

Issues and Strategies Involved in Helping Homeless Parents of Young Children Strengthen Their Self-Esteem

Homeless parents of young children face many stressors that erode their self-esteem. This article articulates these stressors and how they negatively impact homeless parents and their children. Strategies for helping parents empower themselves and their children are explained.     

The contributions of ‘hot’ and ‘cool’ executive function to children's academic achievement, learning-related behaviors, and engagement in kindergarten

Executive functioning (EF) refers to higher order thought processes considered foundational for problem-solving. EF has both ‘cool’ cognitive and ‘hot’ emotional components. This study asks: (a) what are the relative contributions of ‘hot’ and ‘cool’ EF to children's academic achievement? (b) What are the relative contributions of ‘hot’ and ‘cool’ EF to learning-related classroom behaviors and observed engagement? (c) Do learning-related classroom behaviors and observed engagement account for the relation between EF and achievement? For a sample of 173 kindergarteners, cool EF predicted math achievement, learning-related classroom behaviors, and observed engagement. Hot EF did not predict any achievement or behavior outcomes when examined concurrently with cool EF. Children's classroom behavior did not account for the relation between cool EF and math achievement, suggesting cool EF and math performance are directly associated.     

Keeping their attention: Classroom practices associated with behavioral engagement in first grade mathematics classes in China and the United States

This study investigated variation in students’ behavioral engagement across mathematics classes in China and the United States. Student behavioral engagement was examined along with two aspects of the classroom (group size and teacher instructions given about classroom behavior). Video observational data were collected and coded over 1051 time intervals in 35-minute mathematics sessions in Chinese classrooms (n = 8) and comparable American classrooms (n = 7). Latent growth analyses revealed that overall, behavioral engagement declined over time, although the drop-off was dramatically sharper in American classrooms relative to Chinese classrooms. In addition, larger group size and the timing of teacher instructions (given before versus after the behavior) were significantly associated with increased engagement. This study revealed compelling cultural differences as well as patterns in student and teacher behaviors associated with students engaging in on-task behaviors in the classroom. Implications for ways to promote effective classroom behavior are discussed.     

Differential scanning calorimetry: Fundamental overview

This paper discusses the fundamentals of Differential Scanning Calorimetry (DSC) including functions and outputs of a Differential Scanning Calorimeter along with common uses in academia and industry.