Addressing the Needs of Under-Prepared Students in Higher Education: Does College Remediation Work?

Each year, thousands of students graduate high school academically unprepared for college. As a result, approximately one-third of entering postsecondary students require remedial or developmental work before entering college-level courses. However, little is known about the causal impact of remediation on student outcomes. At an annual cost of over $1 billion at public colleges alone, there is a growing debate about its effectiveness. Who should be placed in remediation, and how does it affect their educational progress? This project addresses these critical questions by examining the effects of math and English remediation using a unique dataset of approximately 28,000 students. To account for selection biases, the paper uses variation in remedial placement policies across institutions and the importance of proximity in college choice. The results suggest that students in remediation are more likely to persist in college in comparison to students with similar test scores and backgrounds who were not required to take the courses. They are also more likely to transfer to a higher-level college and to complete a bachelor's degree.

Paying to Learn: The Effect of Financial Incentives on Elementary School Test Scores

Policymakers and academics are increasingly interested in applying financial incentives to individuals in education. This paper presents evidence from a pay for performance program taking place in Coshocton, Ohio. Since 2004, Coshocton has provided cash payments to students in grades three through six for successful completion of their standardized testing. Coshocton determined eligibility for the program using randomization, and using this randomization, this paper identifies the effects of the program on students' academic behavior. We find that math scores improved about 0.15 standard deviations but that reading, social science, and science test scores did not improve.

Thinning Productivity and Cost for a Mechanized Cut-to-Length System in the Northwest Pacific Coast Region of the USA

A production study of a single-grip harvester and forwarder was conducted in a second-growth thinning operation in western Oregon, USA. Production levels for the harvester exceeded 30 m3/ PMH (productive machine hour, delay-free). There was no significant difference in harvester production between stands marked prior to logging and those in which the trees were selected by the operator. Production levels for the forwarder ranged from 10.2 m3 to 14.5 m3/PMH. When landing space was limited, a two-pass forwarding technique (separate loads of sawlogs and pulpwood) was more productive than a single-pass technique (products mixed on each load and sorted at the landing). Regression equations were developed to predict harvester production per PMH on the basis of tree dbh and to predict forwarder production per PMH on the basis of product type, volume per load, and travel distance. Thinning cost for this cut-to-length system wasUS$12.49/m3 [US$35.37/c unit],excluding hauling and a profit-and-risk allowance

Beyond the High Ground: A Taxonomy for Earth-Moon System Operations

Situational and space domain awareness in the space domain can no longer be confined to that which is found in geosynchronous orbit. International activities—commercial and military—and threats to the planet itself exist and are increasing across the entire Earth-Moon system. This reality requires a new taxonomy to accurately classify space domain awareness missions and better apply resources to and development of the same. This work presents such a taxonomy for the classification of space domain awareness regions

Dificultades y posibilidades del algoritmo de optimización de enjambre de partículas para la planificación contemporánea espacial del bosque

We describe here an example of applying particle swarm optimization (PSO) — a population-based heuristic technique — to maximize the net present value of a contemporary southern United States forest plan that includes spatial constraints (green-up and adjacency) and wood flow constraints. When initiated with randomly defined feasible initial conditions, and tuned with some appropriate modifications, the PSO algorithm gradually converged upon its final solution and provided reasonable objective function values. However, only 86% of the global optimal value could be achieved using the modified PSO heuristic. The results of this study suggest that under random-start initial population conditions the PSO heuristic may have rather limited application to forest planning problems with economic objectives, wood-flow constraints, and spatial considerations. Pitfalls include the need to modify the structure of PSO to both address spatial constraints and to repair particles, and the need to modify some of the basic assumptions of PSO to better address contemporary forest planning problems. Our results, and hence our contributions, are contrary to earlier work that illustrated the impressive potential of PSO when applied to stand-level forest planning problems or when applied to a high quality initial population.Se describe aquí un ejemplo de la aplicación de la optimización de enjambre de partículas (PSO) — una técnica heurística basada en la población — para maximizar el valor presente neto de un moderno plan de gestión del bosque del sur de los Estados Unidos, que incluye limitaciones espaciales y restricciones del flujo de madera. Cuando se inicia con condiciones iniciales factibles definidas aleatoriamente, y en sintonía con algunas modificaciones adecuadas, el algoritmo PSO converge gradualmente sobre su solución final y suministra los valores de la función objetivo. Sin embargo, sólo el 86% del valor global óptimo podría lograrse usando la heurística PSO modificada. Los resultados de este estudio sugieren que bajo condiciones de arranque aleatorio de la población inicial, la heurística PSO puede tener una aplicación más bien limitada a los problemas de planificación forestal con objetivos económicos, restricciones de flujo de madera y consideraciones espaciales. Las dificultadas incluyen la necesidad de modificar la estructura de PSO para abordar tanto las limitaciones espaciales como para reparar las partículas, y la necesidad de modificar algunos de los supuestos básicos de PSO para abordar mejor los problemas contemporáneos de la planificación forestal. Nuestros resultados, y por lo tanto nuestra aportación, son contrarios a trabajos anteriores que ilustran el impresionante potencial de PSO cuando se aplica a problemas de planificación forestal a nivel de rodal o cuando se aplica a una población de calidad inicial alta

Improving College Performance and Retention the Easy Way: Unpacking the ACT Exam

Colleges rely on the ACT exam in their admission decisions to increase their ability to differentiate between students likely to succeed and those that have a high risk of under-performing and dropping out. We show that two of the four sub tests of the ACT, English and Mathematics, are highly predictive of positive college outcomes while the other two subtests, Science and Reading, provide little or no additional predictive power. This result is robust across various samples, specifications, and outcome measures. We demonstrate that focusing solely on the English and Mathematics test scores greatly enhances the predictive validity of the ACT exam.

The Role of Simplification and Information in College Decisions: Results from the H&R Block FAFSA Experiment

Growing concerns about low awareness and take-up rates for government support programs like college financial aid have spurred calls to simplify the application process and enhance visibility. This project examines the effects of two experimental treatments designed to test of the importance of simplification and information using a random assignment research design. H&R Block tax professionals helped low- to moderate-income families complete the FAFSA, the federal application for financial aid. Families were then given an estimate of their eligibility for government aid as well as information about local postsecondary options. A second randomly-chosen group of individuals received only personalized aid eligibility information but did not receive help completing the FAFSA. Comparing the outcomes of participants in the treatment groups to a control group using multiple sources of administrative data, the analysis suggests that individuals who received assistance with the FAFSA and information about aid were substantially more likely to submit the aid application, enroll in college the following fall, and receive more financial aid. These results suggest that simplification and providing information could be effective ways to improve college access. However, only providing aid eligibility information without also giving assistance with the form had no significant effect on FAFSA submission rates.

HIV sero-conversion during late pregnancy – when to retest

The South African National Prevention of Mother-to-Child Transmission of HIV programme has resulted in significant reductions in vertical transmission, but new infant HIV infections continue to occur. We present two cases of HIV seroconversion during late pregnancy, demonstrating the limitations of the current programme. These could be mitigated by expanding the programme to include maternal testing at delivery and at immunisation clinic visits as we pursue the elimination of mother-to-child transmission

The Caenorhabditis elegans vulva: A post-embryonic gene regulatory network controlling organogenesis

The Caenorhabditis elegans vulva is an elegant model for dissecting a gene regulatory network (GRN) that directs postembryonic organogenesis. The mature vulva comprises seven cell types (vulA, vulB1, vulB2, vulC, vulD, vulE, and vulF), each with its own unique pattern of spatial and temporal gene expression. The mechanisms that specify these cell types in a precise spatial pattern are not well understood. Using reverse genetic screens, we identified novel components of the vulval GRN, including nhr-113 in vulA. Several transcription factors (lin-11, lin-29, cog-1, egl-38, and nhr-67) interact with each other and act in concert to regulate target gene expression in the diverse vulval cell types. For example, egl-38 (Pax2/5/8) stabilizes the vulF fate by positively regulating vulF characteristics and by inhibiting characteristics associated with the neighboring vulE cells. nhr-67 and egl-38 regulate cog-1, helping restrict its expression to vulE. Computational approaches have been successfully used to identify functional cis-regulatory motifs in the zmp-1 (zinc metalloproteinase) promoter. These results provide an overview of the regulatory network architecture for each vulval cell type

Genuine DNA/polyethylenimine (PEI) Complexes Improve Transfection Properties and Cell Survival

Polyethylenimine (PEI) has been described as one of the most efficient cationic polymers for in vitro gene delivery. Systemic delivery of PEI/DNA polyplexes leads to a lung-expression tropism. Selective in vivo gene transfer would require targeting and stealth particles. Here, we describe two strategies for chemically coupling polyethylene glycol (PEG) to PEI, to form protected ligand-bearing particles. Pre-grafted PEG–PEI polymers lost their DNA condensing property, hence their poor performances. Coupling PEG to pre-formed PEI/DNA particles led to the expected physical properties. However, low transfection efficacies raised the question of the fate of excess free polymer in solution. We have developed a straightforward a purification assay, which uses centrifugation-based ultrafiltration. Crude polyplexes were purified, with up to 60% of the initial PEI dose being removed. The resulting purified and unshielded PEI/DNA polyplexes are more efficient for transfection and less toxic to cells in culture than the crude ones. Moreover, the in vivo toxicity of the polyplexes was greatly reduced, without affecting their efficacy