Academic Support, A Learning Brief

The K-12 Student Success: Out-of-School Time Initiative is focused on boosting student success among Oregon's middle school students. The Oregon Community Foundation and The Ford Family Foundation are currently funding 21 organizations that provide out-of-school-time programming (e.g., after school or summer) to rural students, students of color and low-income students. Funded programs emphasize academic support, positive adult role models and family engagement. This learning brief summarizes what is known about the importance of academic support from existing research and shares what we are learning about the efforts of the Initiative grantees to provide academic support through out-of-school time programming. We hope that this description of the work of the Initiative grantees helps build understanding of the practices and experiences of out-of-school time programs in Oregon.

Evolution of a curved vortex filament into a vortex ring

The deformation of a hairpin-shaped vortex filament under self-induction and in the presence of shear is studied numerically using the Biot-Savart law. It is shown that the tip region of an elongated hairpin vortex evolves into a vortex ring and that the presence of mean shear impedes the process. Evolution of a finite-thickness vortex sheet under self-induction is also investigated using the Navier-Stokes equations. The layer evolves into a hairpin vortex which in turn produces a vortex ring of high Reynolds stress content. These results indicate a mechanism for the generation of ring vortices in turbulent shear flows, and a link between the experimental and numerical observation of hairpin vortices and the observation of ring vortices in the outer regions of turbulent boundary layers

How do you pay? The role of incentives at the point-of-sale

This paper uses discrete-choice models to quantify the role of consumer socioeconomic characteristics, payment instrument attributes, and transaction features on the probability of using cash, debit card, or credit card at the point-of-sale. We use the Bank of Canada 2009 Method of Payment Survey, a two-part survey among adult Canadians containing a detailed questionnaire and a three-day shopping diary. We find that cash is still used intensively at low value transactions due to speed, merchant acceptance, and low costs. Debit and credit cards are used more frequently for higher transaction values where safety, record keeping, the ability to delay payment and credit card rewards gain prominence. We present estimates of the elasticity of using a credit card with respect to credit card rewards. Reward elasticities are a key element in understanding the impact of retail payment pricing regulation on consumer payment instrument usage and welfare. JEL Classification: E41, C35, C83credit card rewards, discrete-choice models, Retail payments

K-12 Student Success: Out-of-School Time Initiative Academic Support

The K-12 Student Success: Out-of-School Time Initiative is focused on boosting student success among Oregon's middle school students. The Oregon Community Foundation and The Ford Family Foundation are currently funding 21 organizations that provide out-of-school-time programming (e.g., after school or summer) to rural students, students of color and low-income students. Funded programs emphasize academic support, positive adult role models and family engagement. This learning brief summarizes what is known about the importance of academic support from existing research and shares what we are learning about the efforts of the Initiative grantees to provide academic support through out-of-school time programming. We hope that this description of the work of the Initiative grantees helps build understanding of the practices and experiences of out-of-school time programs in Oregon

MIT's interferometer CST testbed

The MIT Space Engineering Research Center (SERC) has developed a controlled structures technology (CST) testbed based on one design for a space-based optical interferometer. The role of the testbed is to provide a versatile platform for experimental investigation and discovery of CST approaches. In particular, it will serve as the focus for experimental verification of CSI methodologies and control strategies at SERC. The testbed program has an emphasis on experimental CST--incorporating a broad suite of actuators and sensors, active struts, system identification, passive damping, active mirror mounts, and precision component characterization. The SERC testbed represents a one-tenth scaled version of an optical interferometer concept based on an inherently rigid tetrahedral configuration with collecting apertures on one face. The testbed consists of six 3.5 meter long truss legs joined at four vertices and is suspended with attachment points at three vertices. Each aluminum leg has a 0.2 m by 0.2 m by 0.25 m triangular cross-section. The structure has a first flexible mode at 31 Hz and has over 50 global modes below 200 Hz. The stiff tetrahedral design differs from similar testbeds (such as the JPL Phase B) in that the structural topology is closed. The tetrahedral design minimizes structural deflections at the vertices (site of optical components for maximum baseline) resulting in reduced stroke requirements for isolation and pointing of optics. Typical total light path length stability goals are on the order of lambda/20, with a wavelength of light, lambda, of roughly 500 nanometers. It is expected that active structural control will be necessary to achieve this goal in the presence of disturbances

Emerging role of the KCNT1 Slack channel in intellectual disability

The sodium-activated potassium KNa channels Slack and Slick are encoded by KCNT1 and KCNT2, respectively. These channels are found in neurons throughout the brain, and are responsible for a delayed outward current termed IKNa. These currents integrate into shaping neuronal excitability, as well as adaptation in response to maintained stimulation. Abnormal Slack channel activity may play a role in Fragile X syndrome, the most common cause for intellectual disability and inherited autism. Slack channels interact directly with the Fragile X Mental Retardation protein (FMRP) and IKNa is reduced in animal models of Fragile X syndrome that lack FMRP. Human Slack mutations that alter channel activity can also lead to intellectual disability, as has been found for several childhood epileptic disorders. Ongoing research is elucidating the relationship between mutant Slack channel activity, development of early onset epilepsies and intellectual impairment. This review describes the emerging role of Slack channels in intellectual disability, coupled with an overview of the physiological role of neuronal IKNa currents

K-12 Student Success: Out-of-School time Initiative

This report is a summary of interim findings from the ongoing evaluation of the K-12 Student Success: Out-of-School Time Initiative