Dual Enrollment Policies and Practices

The James Irvine Foundation joins educators and policymakers across the country who share a growing interest in the potential of dual enrollment. In particular, when high school students take college courses to earn transferable college credits, how are they positioned to succeed in college and career? How can we expand this opportunity to a broader range of students? Irvine's Youth program seeks to help increase the number of low-income youth in California who complete high school on time and attain a postsecondary credential by age 25. To ensure access to better educational and economic opportunities for a diverse group of students, our funding supports multiple pathways to the same destination: success in high school, college and careers. The multiple pathways approach integrates rigorous academics with demanding career and technical education, comprehensive student support services and relevant work-based learning opportunities, so that all high school students are prepared for both college and career. Research suggests that career-focused dual enrollment programs can improve secondary and postsecondary academic outcomes for a variety of students. In this context, the Concurrent Courses initiative was created to demonstrate the feasibility of using dual enrollment to enhance career and technical education pathways -- particularly for low-income youth who are struggling academically or who are within populations historically underrepresented in higher education. The Concurrent Courses initiative is being managed by the Community College Research Center (CCRC) housed at Teachers College, Columbia University. We would like to thank and recognize the authors of this brief: Joanne Wang Golann, who is a Senior Research Assistant and Katherine L. Hughes, who is the Assistant Director for Work and Education Reform Research at CCRC. The authors conducted extensive research on the dual enrollment environment in California in preparation for Concurrent Courses. This brief shares their analysis with the field to clarify the opportunities and challenges for supporting promising pathways to college

QUANTIFYING REGULATORY BARRIERS TO ASIAN-U.S. FOOD TRADE

Data on U.S. Food and Drug Administration import detentions and alerts are used to quantify regulatory barriers experienced by Asian food products entering the United States. These data offer the only comprehensive means of assessing regulatory barriers without relying on expert opinion, although they fall short of placing a dollar value on the volume of trade affected. The data show that meeting food regulations is a significant barrier to Asian food products entering the United States, especially for products originating in developing and newly industrialized countries.Asia, food products, regulatory standards, trade, International Relations/Trade,

Calibration, error analysis, and ongoing measurement process monitoring for mass spectrometry

We consider problems of quantifying and monitoring accuracy and precision of measurement in mass spectrometry, particularly in contexts where there is unavoidable day-to-day/period-to-period changes in instrument sensitivity. First we consider the issue of estimating instrument sensitivity based on data from a typical calibration study. Simple method-of-moments methods, likelihood-based methods, and Bayes methods based on the one-way random effects model are illustrated. Then we consider subsequently assessing the precision of an estimate of a mole fraction of a gas of interest in an unknown. Finally, we turn to the problem of ongoing measurement process monitoring and illustrate appropriate set-up of Shewhart control charts in this application. --

A Simple Apparatus for Measuring Cell Settling Velocity

Accurate cell settling velocity determination is critical for perfusion culture using a gravity settler for cell retention. We have developed a simple apparatus (a \u27settling column\u27) for measuring settling velocity and have validated the procedure with 15-μm polystyrene particles with known physical properties. The measured settling velocity of the polystyrene particles is within 4% of the value obtained using the traditional Stokes\u27 law approach. The settling velocities of three hybridoma cell lines were measured, resulting in up to twofold variation among cell lines, and the values decreased as the cell culture aged. The settling velocities of the nonviable cells were 33-50% less than the corresponding viable cells. The significant variation of settling velocities among cell populations and growth phases confirms the necessity of routine measurement of this property during long-term perfusion culture

Nonparametric estimation of correlation functions in longitudinal and spatial data, with application to colon carcinogenesis experiments

In longitudinal and spatial studies, observations often demonstrate strong correlations that are stationary in time or distance lags, and the times or locations of these data being sampled may not be homogeneous. We propose a nonparametric estimator of the correlation function in such data, using kernel methods. We develop a pointwise asymptotic normal distribution for the proposed estimator, when the number of subjects is fixed and the number of vectors or functions within each subject goes to infinity. Based on the asymptotic theory, we propose a weighted block bootstrapping method for making inferences about the correlation function, where the weights account for the inhomogeneity of the distribution of the times or locations. The method is applied to a data set from a colon carcinogenesis study, in which colonic crypts were sampled from a piece of colon segment from each of the 12 rats in the experiment and the expression level of p27, an important cell cycle protein, was then measured for each cell within the sampled crypts. A simulation study is also provided to illustrate the numerical performance of the proposed method.Comment: Published in at http://dx.doi.org/10.1214/009053607000000082 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Early growth response gene 2 (Egr-2) controls the self-tolerance of T cells and prevents the development of lupuslike autoimmune disease

© 2008 Zhu et al. This article is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 3.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/3.0/).Maintaining tolerance of T cells to self-antigens is essential to avoid autoimmune disease. How self-reactive T cells are kept functionally inactive is, however, unknown. In this study, we show that early growth response gene 2 (Egr-2), a zinc-finger transcription factor, is expressed in CD44(high) T cells and controls their proliferation and activation. In the absence of Egr-2, CD44(high), but not CD44(low) T cells, are hyperreactive and hyperproliferative in vivo. The accumulation of activated CD4(+)CD44(high) T cells leads to the development of a late onset lupuslike autoimmune disease characterized by the accumulation of interferon (IFN)-gamma and interleukin (IL)-17-producing CD4(+) T cells, loss of tolerance to nuclear antigens, massive infiltration of T cells into multiple organs and glomerulonephritis. We found that the expression of cyclin-dependent kinase inhibitor p21cip1 was impaired in Egr-2-deficient T cells, whereas the expression of IFN-gamma and IL-17 in response to T cell receptor ligation was significantly increased, suggesting that Egr-2 activates the expression of genes involved in the negative regulation of T cell proliferation and inflammation. These results demonstrate that Egr-2 is an intrinsic regulator of effector T cells and controls the expansion of self-reactive T cells and development of autoimmune disease.The Biotechnology and Biological Sciences Research Council, the Medical Research Council and the Wellcome Trust

RIN1 Is an ABL Tyrosine Kinase Activator and a Regulator of Epithelial-Cell Adhesion and Migration

SummaryBackground: ABL tyrosine kinases control actin remodeling in development and in response to environmental stimuli. These changes affect cell adhesion, cell migration, and cell-cell contact. Little is known, however, about upstream mechanisms regulating ABL protein activation.Results: We report that the RAS effector RIN1 is an activator of ABL tyrosine kinases. RIN1 expression in fibroblasts promotes the formation of membrane spikes; similar effects have been reported for ABL overexpression. RIN1 binds to the ABL SH3 and SH2 domains, and these interactions stimulate ABL2 catalytic activity. This leads to increased phosphorylation of CRK and CRKL, inhibiting these cytoskeletal regulators by promoting intramolecular over intermolecular associations. Activated RAS participates in a stable RAS-RIN1-ABL2 complex and stimulates the tyrosine kinase-activation function of RIN1. Deletion of the RAS binding domain (RBD) strongly stimulated the ABL2 activation function of RIN1, suggesting that RAS activation results from the relief of RIN1 autoinhibition. The ABL binding domain of RIN1 (RIN1-ABD) increased the activity of ABL2 immune complexes and purified RIN1-ABD-stimulated ABL2 kinase activity toward CRK. Mammary epithelial cells (MECs) from Rin1−/− mice showed accelerated cell adhesion and increased motility in comparison to wild-type cells. Knockdown of RIN1 in epithelial-cell lines blocked the induction of CRKL phosphorylation, confirming that RIN1 normally functions as an inhibitor of cell motility.Conclusions: RIN1 is a directly binding ABL tyrosine kinase activator in cells as well as in a defined-component assay. In response to environmental changes, this novel signal pathway mediates actin remodeling associated with adhesion and migration of epithelial cells

Evaluation of an Inclined Gravity Settler for Microalgae Harvesting

BACKGROUND Given the small size of microalgae, and the low biomass concentrations obtained in light-limited cultures, the cost of algae harvesting is a significant barrier to commercial-scale production of biofuel from algae. A downward- flow inclined gravity settler was evaluated for its effectiveness in dewatering the microalgae Scenedesmus dimorphus and Chlorella vulgaris. RESULTS Experimental results showed that S. dimorphus can be concentrated up to 8-fold using a single settler stage, with a biomass recovery of 80%. Separation efficiency was independent of biomass concentration between 1 and 5 gdw L-1, suggesting that a two-stage sequential system of settlers may maximize biomass recovery and concentration effectively. Efficiency of separation of C. vulgaris was slightly lower than that of S. dimorphus, most likely due to the fact that S. dimorphus exist in aggregates of four or more cells and thus may settle more easily. CONCLUSION The downward-flow inclined gravity settler demonstrated consistent results with 72% efficiency in biomass recovery and low operating costs. This separation system warrants further investigation at the industrial scale, for the harvesting of algae from dilute cell suspensions, with applications to biofuels. (c) 2013 Society of Chemical Industr