Shape sensitivity analysis of wing static aeroelastic characteristics

A method is presented to calculate analytically the sensitivity derivatives of wing static aeroelastic characteristics with respect to wing shape parameters. The wing aerodynamic response under fixed total load is predicted with Weissinger's L-method; its structural response is obtained with Giles' equivalent plate method. The characteristics of interest include the spanwise distribution of lift, trim angle of attack, rolling and pitching moments, wind induced drag, as well as the divergence dynamic pressure. The shape parameters considered are the wing area, aspect ratio, taper ratio, sweep angle, and tip twist angle. Results of sensitivity studies indicate that: (1) approximations based on analytical sensitivity derivatives can be used over wide ranges of variations of the shape parameters considered, and (2) the analytical calculation of sensitivity derivatives is significantly less expensive than the conventional finite-difference alternative

Sbf/MTMR13 coordinates PI(3)P and Rab21 regulation in endocytic control of cellular remodeling.

Cells rely on the coordinated regulation of lipid phosphoinositides and Rab GTPases to define membrane compartment fates along distinct trafficking routes. The family of disease-related myotubularin (MTM) phosphoinositide phosphatases includes catalytically inactive members, or pseudophosphatases, with poorly understood functions. We found that Drosophila MTM pseudophosphatase Sbf coordinates both phosphatidylinositol 3-phosphate (PI(3)P) turnover and Rab21 GTPase activation in an endosomal pathway that controls macrophage remodeling. Sbf dynamically interacts with class II phosphatidylinositol 3-kinase and stably recruits Mtm to promote turnover of a PI(3)P subpool essential for endosomal trafficking. Sbf also functions as a guanine nucleotide exchange factor that promotes Rab21 GTPase activation associated with PI(3)P endosomes. Of importance, Sbf, Mtm, and Rab21 function together, along with Rab11-mediated endosomal trafficking, to control macrophage protrusion formation. This identifies Sbf as a critical coordinator of PI(3)P and Rab21 regulation, which specifies an endosomal pathway and cortical control

The Evaluation of Enhanced Academic Instruction in After-School Programs: Findings After the First Year of Implementation

This report presents one-year implementation and impact findings on two supplemental academic instruction approaches developed for after-school settings -- one for math and one for reading. Compared with regular after-school programming, the supplemental math program had impacts on student SAT 10 test scores and the supplemental reading program did not --although the reading program had some effect on reading fluency

Water yield estimation and sedimentation control in two Volta sub-basins: tools towards integrated water resources management

Small reservoirs form a major source of water supply in the Volta basin. However, sedimentation of reservoirs poses serious threats to overall water yield and storage, consequently impacting community water supplies and livelihoods. This study will assess basin-level water yields and sediment inflow deposited in reservoirs in two Volta sub-basins using the WEAP and SWAT models in combination with spatial analysis techniques. The WEAP Model will assess water allocations while the SWAT model will compute water balance, runoff and sediment yields. Ancillary measured sediment yield data will be used in combination with terrain-based distributed models in a GIS to identify and predict major areas of erosion in the two study sites. Social and biophysical dynamics will be concomittantly assessed through a multi-agent modeling framework (ComMod). To this end, the WEAP and SWAT models will be linked to the computer simulation tool of the ComMod platform. This will allow for assessing the consequences of local practices -and possibly proposed intervention- in terms of erosion (see figure). The results and the approach can be used as decision-support tools to identify practical IWRM interventions that reduce erosion e.g. vegetation strip-ways. It is anticipated that this will result in improved water resources management and reduce impacts of drought spell shocks on the affected communities and could be replicated elsewhere in the Volta basin. (Texte intégral

User-Fee Financing of USDA Meat and Poultry Inspection

USDA's Food Safety and Inspection Service (FSIS) finances about 13.5 percent of its budget outlays through user fees for overtime and unscheduled meat and poultry inspections. User fees play an increasingly important role in financing government programs, and FSIS has frequently requested expanded authority to charge user fees for more of its operations. Congress has consistently rejected the FSIS requests and has placed important restrictions on fees and the uses of fee revenue at those agencies that have been granted more extensive user fee authority. This report surveys the application of user-fees for financing meat and poultry inspection programs in other countries; reviews user-fee systems in other Federal agencies, particularly those with food and agricultural missions or regulatory responsibilities; and discusses the relevant economics literature on the use and design of user fees. Finally, we suggest several elements that should underlie the structure of user fees for meat and poultry inspection, should such a program be introduced. euser fees, meat inspection, public finance, Livestock Production/Industries, Public Economics,