Initial Impacts of No Child Left Behind on Elementary Science Education

This research examines the impact of the No Child Left Behind (NCLB) Act on elementary science education within a Midwestern state possessing strong national education measures. Elementary teachers (N = 164) responded to an online survey, which included both closed-ended and open-ended questions pertaining to science instruction and changes made in science instruction since the implementation of NCLB. More than half of these teachers indicated they have cut time from science instruction since NCLB became a law. The reason given for this decrease in science education was mainly the need to increase time for math and reading instruction

Comment: Monitoring Networked Applications With Incremental Quantile Estimation

Our comments are in two parts. First, we make some observations regarding the methodology in Chambers et al. [arXiv:0708.0302]. Second, we briefly describe another interesting network monitoring problem that arises in the context of assessing quality of service, such as loss rates and delay distributions, in packet-switched networks.Comment: Published at http://dx.doi.org/10.1214/088342306000000600 in the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Workers' Trust Funds and the Logic of Wage Profiles

This paper defines a concept, a worker's trust fund, which is useful in analyzing optimal age-earnings profiles. The trust fund represents what a worker loses if dismissed from a job for shirking. In considering whether to work or shirk, a worker weighs the potential loss due to forfeiture of the trust fund if caught shirking against the benefits from reduced effort. This concept is used to show that the implicit bonding in upward sloping age-earnings profiles is not a perfect substitute for an explicit upfront performance bond (or employment fee). It is also shown that the second-best optimal earnings profile in the absence of an upfront employment fee pays total compensation in excess of market clearing in a variety of stylized cases.

Do Deferred Wages Dominate Involuntary Unemployment as a Worker Discipline Device?

In the most widely analyzed type of efficiency wage model of involuntary unemployment, firms pay wages in excess of market clearing to give workers an incentive not to shirk. Such payments in excess of market clearing and the resultant equilibrium unemployment act as a worker discipline device. This paper concerns what is usually considered the most important theoretical criticism of such models: the so-called bonding argument. The essence of the bonding critique is that contracts whereby workers pay a bond to the firm upon taking a job (or pay an employment fee to gain employment) can eliminate involuntary unemployment. Explicit upfront bonds are only quite rarely observed. A more subtle form of the bonding critique argues that implicit bonding through upward sloping wage profiles and other deferred payment schemes can perfectly substitute for upfront bonds in providing incentives not to shirk and thereby allow the labor market to clear. This paper shows that upward sloping wage profiles do not act as a perfect substitute for explicit bonds in a natural extension of the shirking model in which workers are finite lived, the monitoring of worker behaviors on the job is costly, and firms have reputations for honesty as employers. In the absence of direct upfront bonding, optimal payment schedules will be in excess of market clearing. The reason why upward sloping wage profiles that are market clearing will not generally be the optimal labor contract is simple: delayed payment may provide sufficient incentive to prevent shirking late in the life of the contract, but in the beginning of the contract it does not prevent shirking. And it turns out in a variety of stylized cases, it is cheaper for the firm to pay a wage premium rather than to accept worker shirking early in the contract. The implications of potential worker malfeasance in the absence of explicit bonds for compensation schedules, job assignments, and firm monitoring strategies over the course of a worker's career are also analyzed.

Fast Search for Dynamic Multi-Relational Graphs

Acting on time-critical events by processing ever growing social media or news streams is a major technical challenge. Many of these data sources can be modeled as multi-relational graphs. Continuous queries or techniques to search for rare events that typically arise in monitoring applications have been studied extensively for relational databases. This work is dedicated to answer the question that emerges naturally: how can we efficiently execute a continuous query on a dynamic graph? This paper presents an exact subgraph search algorithm that exploits the temporal characteristics of representative queries for online news or social media monitoring. The algorithm is based on a novel data structure called the Subgraph Join Tree (SJ-Tree) that leverages the structural and semantic characteristics of the underlying multi-relational graph. The paper concludes with extensive experimentation on several real-world datasets that demonstrates the validity of this approach.Comment: SIGMOD Workshop on Dynamic Networks Management and Mining (DyNetMM), 201

The Evolution of the Mexican-Born Workforce in the United States

This paper examines the evolution of the Mexican-born workforce in the United States using data drawn from the decennial U.S. Census throughout the entire 20th century. It is well known that there has been a rapid rise in Mexican immigration to the United States in recent years. Interestingly, the share of Mexican immigrants in the U.S. workforce declined steadily beginning in the 1920s before beginning to rise in the 1960s. It was not until 1980 that the relative number of Mexican immigrants in the U.S. workforce was at the 1920 level. The paper examines the trends in the relative skills and economic performance of Mexican immigrants, and contrasts this evolution with that experienced by other immigrants arriving in the United States during the period. The paper also examines the costs and benefits of this influx by examining how the Mexican influx has altered economic opportunities in the most affected labor markets and by discussing how the relative prices of goods and services produced by Mexican immigrants may have changed over time.

GEOTAIL Spacecraft historical data report

The purpose of this GEOTAIL Historical Report is to document ground processing operations information gathered on the GEOTAIL mission during processing activities at the Cape Canaveral Air Force Station (CCAFS). It is hoped that this report may aid management analysis, improve integration processing and forecasting of processing trends, and reduce real-time schedule changes. The GEOTAIL payload is the third Delta 2 Expendable Launch Vehicle (ELV) mission to document historical data. Comparisons of planned versus as-run schedule information are displayed. Information will generally fall into the following categories: (1) payload stay times (payload processing facility/hazardous processing facility/launch complex-17A); (2) payload processing times (planned, actual); (3) schedule delays; (4) integrated test times (experiments/launch vehicle); (5) unique customer support requirements; (6) modifications performed at facilities; (7) other appropriate information (Appendices A & B); and (8) lessons learned (reference Appendix C)

Conservation Value and Permeability of Neotropical Oil Palm Landscapes for Orchid Bees

The proliferation of oil palm plantations has led to dramatic changes in tropical landscapes across the globe. However, relatively little is known about the effects of oil palm expansion on biodiversity, especially in key ecosystem-service providing organisms like pollinators. Rapid land use change is exacerbated by limited knowledge of the mechanisms causing biodiversity decline in the tropics, particularly those involving landscape features. We examined these mechanisms by undertaking a survey of orchid bees, a well-known group of Neotropical pollinators, across forest and oil palm plantations in Costa Rica. We used chemical baits to survey the community in four regions: continuous forest sites, oil palm sites immediately adjacent to forest, oil palm sites 2km from forest, and oil palm sites greater than 5km from forest. We found that although orchid bees are present in all environments, orchid bee communities diverged across the gradient, and community richness, abundance, and similarity to forest declined as distance from forest increased. In addition, mean phylogenetic distance of the orchid bee community declined and was more clustered in oil palm. Community traits also differed with individuals in oil palm having shorter average tongue length and larger average geographic range size than those in the forest. Our results indicate two key features about Neotropical landscapes that contain oil palm: 1) oil palm is selectively permeable to orchid bees and 2) orchid bee communities in oil palm have distinct phylogenetic and trait structure compared to communities in forest. These results suggest that conservation and management efforts in oil palm-cultivating regions should focus on landscape features.This work was supported by a Hosteling International-Austin Travel Fellowship (http://www.hiusa.org/austin) and a grant from the Graduate Program in Ecology, Evolution and Behavior at the University of Texas (http://www.biosci.utexas.edu/graduate/ee​b/default.aspx) to GL. GL was supported by a US National Science Foundation Graduate Research Fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Integrative BiologyEmail: [email protected]