Whose Schools Are Failing?

Persistent school segregation does not mean just that children of dierent racial and ethnic backgrounds attend dierent schools, but that their schools are also unequal in their students' performance. This study documents nationally the extent of disparities in student performance between schools attended by whites and Asians compared to blacks, Hispanics, and Native Americans. The analysis shows that a focus solely on schools at the bottom of the distribution as in No Child Left Behind would only modestly reduce the wide disparities between groups

EFFECTS OF EBT CUSTOMER SERVICE WAIVERS ON FOOD STAMP RECIPIENTS: EXECUTIVE SUMMARY

Most State agencies are now using electronic benefits transfer (EBT) systems to issue food stamp benefits. To promote operational efficiency, some States have received waivers of certain rules governing EBT use. An exploratory study was conducted to ascertain the effects of these waivers on food stamp recipients. The results show that two of the waivers-those allowing recipients to select their own personal identification numbers and to receive EBT training by mail rather than in person-cause new food stamp recipients in waiver States to have more difficulties in using the electronic system than new recipients in nonwaiver States. Further, the difficulties are more apparent among the elderly or disabled. However, the problems tend to disappear as new users gain EBT experience. A third waiver, extending time for card replacement via mail, showed mixed benefits for recipients, most of whom prefer to pick up the card at a food stamp office. Perhaps the most important conclusion is that the customer service waivers do not affect recipient satisfaction with the EBT system; the high level of satisfaction that they expressed suggests that most problems with the waivers are either transitory or minor. The full report is available online. See Effects of EBT Customer Service Waivers on Food Stamp Recipients: Final Report, at: http://www.ers.usda.gov/publications/efan02007EBT, new recipients, customer service, vulnerable subgroups, recipient satisfaction, Food Consumption/Nutrition/Food Safety, Food Security and Poverty,

A novel DSM philosophy for building integrated renewable systems

This paper presents an overview of a novel concept in IT network design and power control focused on matching building integrated renewable power generation with local demands. It describes how this is achieved through combination of energy demand reduction and dynamic utilisation of embedded energy storage in a robust, efficient and cost effective manner. A brief overview of the main features of the design is given in terms of its intended benefits as an integrated system. The load components and distribution topology are described for this experimental system within the limits set by the capacity, capabilities and desired function of the network. Power supply to the network is described as including a back-up source to the photovoltaic (PV) source to add functionality and stability with no requirements for undesirable exporting of excess PV generation. The necessary configuration of the renewable array integrating with the network is also highlighted with an example compatible solar module device. A trial of the technology and demand management control in a high profile office building is described. This trial in a live working environment is providing invaluable real world data to compare against modelling and network simulation results

Rethinking the Liquidity Puzzle: Application of a New Measure of the Economic Money Stock

Historically, attempts to solve the liquidity puzzle have focused on narrowly defined monetary aggregates, such as non-borrowed reserves, the monetary base, or M1. Many of these efforts have failed to find a short-term negative correlation between interest rates and monetary policy innovations. More recent research uses sophisticated macroeconomic and econometric modeling. However, little research has investigated the role measurement error plays in the liquidity puzzle, since in nearly every case, work investigating the liquidity puzzle has used one of the official monetary aggregates, which have been shown to exhibit significant measurement error. This paper examines the role that measurement error plays in the liquidity puzzle by (i) providing a theoretical framework explaining how the official simple-sum methodology can lead to a liquidity puzzle, and (ii) testing for the liquidity effect by estimating an unrestricted VAR.Liquidity Puzzle, Monetary Policy, Monetary Aggregation, Money Stock, Divisia Index Numbers

Rethinking the Liquidity Puzzle: Application of a New Measure of the Economic Money Stock

Historically, attempts to solve the liquidity puzzle have focused on narrowly defined monetary aggregates, such as non-borrowed reserves, the monetary base, or M1. Many of these efforts have failed to find a short-term negative correlation between interest rates and monetary policy innovations. More recent research uses sophisticated macroeconomic and econometric modeling. However, little research has investigated the role measurement error plays in the liquidity puzzle, since in nearly every case, work investigating the liquidity puzzle has used one of the official monetary aggregates, which have been shown to exhibit significant measurement error. This paper examines the role that measurement error plays in the liquidity puzzle by (i) providing a theoretical framework explaining how the official simple-sum methodology can lead to a liquidity puzzle, and (ii) testing for the liquidity effect by estimating an unrestricted VAR.North-South, growth model, innovation assimilation

Toward a Bias Corrected Currency Equivalent Index

Measuring the economic stock of money, defined to be the present value of current and future monetary service flows, is a difficult asset pricing problem, because most monetary assets yield interest. Thus, an interest yielding monetary asset is a joint product: a durable good providing a monetary service flow and a financial asset yielding a return. The currency equilivant index provides an elegant solution, but it does so by making strong assumptions about expectations of future monetary service flows. These assumptions cause the currency equivalent index to exhibit significant downward bias. In this paper, we propose an extension to the currency equivalent index that will correct for a significant amount of this bias.Currency Equilivant Index, Monetary Aggregation, Money Stock

Tracking diet and movement of Atlantic bluefin tuna (Thunnus thynnus) using carbon and nitrogen stable isotopes

Atlantic bluefin tuna (ABFT; Thunnus thynnus) are important top predators in pelagic ecosystems. Understanding their diet and movements is necessary for proper management, but existing methods are costly and logistically challenging. Naturally occurring stable isotopes have been used to study diet and movement in many aquatic ecosystems and offer a novel approach for studying these large pelagic fishes. Lipids, which have lower carbon isotope values than protein, can affect isotope analyses of bulk tissue. Both chemical and mathematical corrections were used to address lipid effects on ABFT and the prey. All chemical extraction methods altered nitrogen isotope values. Mathematical corrections closely replicated chemically extracted carbon values while preserving nitrogen isotope and C:N values and were applied to all ABFT samples. Combined stomach content and stable isotope analyses were performed on ABFT in coastal forage grounds, revealing a diet based on aggregations of small fish and crustaceans. The largest prey components of adult ABFT were Atlantic herring (Clupea harengus) and sand lance ( Ammodytes spp.) in the Gulf of Maine and Atlantic menhaden ( Brevoortia tyrannus) and swimming crabs (Portunus spp.) in the Mid-Atlantic Bight. Juvenile bluefin tuna fed at a lower trophic level than adult conspecifics due to higher dietary proportions of crustaceans and smaller fishes. Diet composition of ABFT in the western Atlantic was similar to historical observations while juveniles in the Bay of Biscay fed on higher proportions of crustacean prey relative to past observations. Isotope gradients detected between shelf and open ocean forage grounds were used to infer movements of adult ABFT into Gulf of Mexico spawning grounds and to estimate residency in Gulf of Maine forage grounds in relation to results from tagging experiments. Residency and arrival times varied among individuals in the Gulf of Maine, with late season arrivals having reduced body condition similar to early season fish. Most fish in the Gulf of Mexico had previously fed on shelf forage grounds, demonstrating connectivity between productive coastal waters and this western Atlantic spawning area. Results provide important trophic and migratory information for use in ecosystem-based management strategies and validations for future isotope studies of large pelagic fishes

A New Class of Improved Bandwidth Planar Ultrawideband Modular Antenna (puma) Arrays Scalable to mm-Waves

A new class of Planar Ultrawideband Modular Antenna (PUMA) arrays, termed PUMAv3, is introduced to offer improved performance and further meet demand needs for multifunctional systems. PUMAv3 extends the frequency scalability of PUMA arrays to mm-waves (approximately 50 GHz) and improves bandwidth by 50\% without the use of a matching network or external baluns. The major enabling technical innovation is the advent of a new common-mode mitigation mechanism that relies upon capacitively-loaded shorting vias to push broadside catastrophic resonances below the operating band without inhibiting low-end bandwidth performance. Ridged waveguide models are employed to explain the operational principles and accurately predict the location of the common-mode frequency within the new array topology. Additionally, the superstrate loading scheme is split into two exclusive layers to enhance broadside and wide angle impedance levels while maintaining the highest frequency at 97% of the grating lobe frequency and reducing the overall array profile by up to 30%. The PUMAv3 also retains the attractive practical advantages inherent to the PUMA array family: aperture modularity, direct 50-ohm feeding, and low-cost planar multilayer PCB fabrication. Infinite array full-wave simulations of a dual-polarized PUMAv3 satisfying manufacture guidelines suggest 10.6-47.6 GHz (4.5:1) operation with strong VSWR levels out to 45 degrees, high port isolation and low cross-polarization