Navigating the Middle Grades: Evidence from New York City

Educators have long asserted that the middle grade years (typically, grades six through eight) are a time of both great importance and vulnerability in students' K-12 schooling. Anecdotal and empirical evidence suggest that students encounter new social and emotional challenges, increased academic demands, and major developmental transitions during the middle grade years. In this study, we investigate whether and how students' achievement and attendance change between grade four and eight and identified moments during this period when students' achievement and attendance suggest that they will struggle to graduate from high school within four years

United States v. Robinson

This article provides an overview of fourth amendment litigation that focused on the question of what constitutes an “unreasonable” search. The Supreme Court had previously provided guidance in Terry v. Ohio and Chimel v. California. This article provides a brief overview of these cases, and then it turns to more thoroughly examine the decision in US v. Robinson

Cost-Effectiveness Analysis of Early Reading Programs: A Demonstration With Recommendations for Future Research

We review the value of cost-effectiveness analysis for evaluation and decision making with respect to educational programs and discuss its application to early reading interventions. We describe the conditions for a rigorous cost-effectiveness analysis and illustrate the challenges of applying the method in practice, providing examples of programs for which we have estimated costs, but find effectiveness data lacking in comparability. We provide a demonstration of how cost-effectiveness analysis can be applied to two early reading programs: the Wilson Reading System and Corrective Reading. We use existing effectiveness data from an experimental evaluation in which the programs were implemented under similar conditions and the use of common outcomes measures for both programs yielded data that are comparable. We combine these data with cost data we collected using the ingredients method to calculate cost-effectiveness ratios for the alphabetics domain. A complete picture of the relative cost-effectiveness of each program could be provided if effectiveness metrics were available for fluency, vocabulary, and comprehension. We highlight the obstacles to applying cost-effectiveness analysis more frequently and recommend strategies for improving the availability of the requisite data

Periodic Lamellipodial Contractions Correlate with Rearward Actin Waves

AbstractCellular lamellipodia bind to the matrix and probe its rigidity through forces generated by rearward F-actin transport. Cells respond to matrix rigidity by moving toward more rigid matrices using an unknown mechanism. In spreading and migrating cells we find local periodic contractions of lamellipodia that depend on matrix rigidity, fibronectin binding and myosin light chain kinase (MLCK). These contractions leave periodic rows of matrix bound β3-integrin and paxillin while generating waves of rearward moving actin bound α-actinin and MLCK. The period between contractions corresponds to the time for F-actin to move across the lamellipodia. Shortening lamellipodial width by activating cofilin decreased this period proportionally. Increasing lamellipodial width by Rac signaling activation increased this period. We propose that an actin bound, contraction-activated signaling complex is transported locally from the tip to the base of the lamellipodium, activating the next contraction/extension cycle

Raman spectroscopic analysis of cell differentiation and death modes

Raman spectroscopy provides opportunities for non-invasive, non-destructive, label-free analysis of cell states based on changes in the biochemical composition of cells. We are investigating the suitability of Raman spectroscopy to assess the stages of human embryonic stem cell (hESC) differentiation towards pancreatic insulin-positive cells. Raman microspectrometry analysis has revealed macromolecular composition differences over time that distinguished cell populations differentiating to pancreatic cell types, such as by an increase in the protein-to-nucleic acid signal ratio and to distinguish the presence of insulin. Added insight into these macromolecular changes were provided by principal component analysis (PCA) of the data. However, the application of PCA can be difficult to interpret. The usefulness of non-negative matrix factorization was explored to improve the interpretability of overlapping Raman bands. We demonstrated the utility of this procedure by analyzing spectra to determine the cellular insulin or glucagon content. Thus, Raman spectroscopy can detect such differences in cells to detect the desired product as well as the potential to detect residual hESCs or the emergence of unwanted cells. We also investigated the suitability of Raman spectroscopy to detect the onset and types of cell death. Apoptotic, necrotic or autophagic Chinese Hamster Ovary cells were compared to uninduced cultures using Raman spectroscopy and PCA. Furthermore, uninduced cells were compared to cells sorted at different stages of apoptosis to determine how early the onset of apoptosis could be detected. Changes were observed in several peaks during the course of cell death, with repeated changes observed in nucleic acid- and lipid-associated peaks, enabling the distinction of cell death modes. Application of such death monitoring capabilities to cellular therapy cultures should be even more useful, given the need for more process analytical technologies to address the often more variable performance of these cultures, especially when adaptive control is needed for primary cell derived manufacturing

Process analytical utility of Raman spectroscopy for cell therapy manufacturing

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