Equity and Excellence in Education--Compatible Concepts or Hostile Abstractions?

Since 1983, with the publication of five well-known national reports calling for reform in education,[2] the later release of other reports by prestigious groups (such as the Carnegie Task Force on Teaching as a Profession and the Holmes Group), and the enactment of approximately 700 state statutes focused on school reform,[3] the push for excellence has overshadowed earlier commitments to equity in schools. As Orlich writes, In at least one instance, implementing the proposals of these two groups [Carnegie and Holmes] would have the same undesirable effect: reducing the number of minority teachers from few to virtually none. [4] This movement for excellence has had a narrowing effect on the level of social consciousness concerning sex and race equity in schools and in society. Any movement which restricts the growth of equity should be examined critically; for it, both as a topic of study and as a fact in practice, is a necessary component of an excellent and complete preparation of teachers in a pluralistic society. By providing programs that both preach and practice equity principles, today\u27s teacher educators assist the next generation of teachers to develop a contextual understanding of the field of teaching and a heightened social consciousness of their role in education

[Review of] Silvester J. Brito. Looking Through a Squared Off Circle

Twenty two poems shimmer with irridescence [iridescence] in Looking Through a Squared Off Circle. The interaction of shifting colors and tones in Silvester Brito\u27s poems flood the reader\u27s mind with the bittersweet pain and beauty of the American Indian experience

Relative intensity squeezing by four-wave mixing with loss: an analytic model and experimental diagnostic

Four-wave mixing near resonance in an atomic vapor can produce relative intensity squeezed light suitable for precision measurements beyond the shot-noise limit. We develop an analytic distributed gain/loss model to describe the competition of mixing and absorption through the non-linear medium. Using a novel matrix calculus, we present closed-form expressions for the degree of relative intensity squeezing produced by this system. We use these theoretical results to analyze experimentally measured squeezing from a $^{85}$Rb vapor and demonstrate the analytic model's utility as an experimental diagnostic.Comment: 10 pages, 5 figure

Perceptions of personal risk in tourists’ destination choices: nature tours in Mexico

Terrorism, pandemic diseases, and other threatening events have recently heightened the sense of personal risk for tourists considering international travel. This article addresses the paucity of research assessing perceptions of risk both before and during travel to risky destinations. Tourists on two nature tours in Mexico were interviewed and observed while engaged in the travel. Many types of specific perceived risks were uncovered, including insect-borne disease, traffic accidents, financial losses, and unattained goals. Some correlates of perceived risk were tour company reputation, stage of family life cycle, age, and motivation. Based on the types of perceived risk and the factors, five propositions are discussed. One unexpected proposition addresses the role of age and states that as the perceived years of physical ability to travel decreases, the tolerance for safety risk increases. Another proposes that eco-tourists with intense, destination- specific motivations are more tolerant of travel risk than those with casual and/or social motivations. The article concludes with suggestions for tour industry managers and directions for future research

Estimating population size using the network scale up method

We develop methods for estimating the size of hard-to-reach populations from data collected using network-based questions on standard surveys. Such data arise by asking respondents how many people they know in a specific group (e.g., people named Michael, intravenous drug users). The Network Scale up Method (NSUM) is a tool for producing population size estimates using these indirect measures of respondents' networks. Killworth et al. [Soc. Netw. 20 (1998a) 23-50, Evaluation Review 22 (1998b) 289-308] proposed maximum likelihood estimators of population size for a fixed effects model in which respondents' degrees or personal network sizes are treated as fixed. We extend this by treating personal network sizes as random effects, yielding principled statements of uncertainty. This allows us to generalize the model to account for variation in people's propensity to know people in particular subgroups (barrier effects), such as their tendency to know people like themselves, as well as their lack of awareness of or reluctance to acknowledge their contacts' group memberships (transmission bias). NSUM estimates also suffer from recall bias, in which respondents tend to underestimate the number of members of larger groups that they know, and conversely for smaller groups. We propose a data-driven adjustment method to deal with this. Our methods perform well in simulation studies, generating improved estimates and calibrated uncertainty intervals, as well as in back estimates of real sample data. We apply them to data from a study of HIV/AIDS prevalence in Curitiba, Brazil. Our results show that when transmission bias is present, external information about its likely extent can greatly improve the estimates. The methods are implemented in the NSUM R package.Comment: Published at http://dx.doi.org/10.1214/15-AOAS827 in the Annals of Applied Statistics (http://www.imstat.org/aoas/) by the Institute of Mathematical Statistics (http://www.imstat.org

A chemical ionization mass spectrometer for continuous underway shipboard analysis of dimethylsulfide in near-surface seawater

A compact, low-cost atmospheric pressure, chemical ionization mass spectrometer ("mini-CIMS") has been developed for continuous underway shipboard measurements of dimethylsulfide (DMS) in seawater. The instrument was used to analyze DMS in air equilibrated with flowing seawater across a porous Teflon membrane equilibrator. The equilibrated gas stream was diluted with air containing an isotopically-labeled internal standard. DMS is ionized at atmospheric pressure via proton transfer from water vapor, then declustered, mass filtered via quadrupole mass spectrometry, and detected with an electron multiplier. The instrument described here is based on a low-cost residual gas analyzer (Stanford Research Systems), which has been modified for use as a chemical ionization mass spectrometer. The mini-CIMS has a gas phase detection limit of 220 ppt DMS for a 1 min averaging time, which is roughly equivalent to a seawater DMS concentration of 0.1 nM DMS at 20°C. The mini-CIMS has the sensitivity, selectivity, and time response required for underway measurements of surface ocean DMS over the full range of oceanographic conditions. The simple, robust design and relatively low cost of the instrument are intended to facilitate use in process studies and surveys, with potential for long-term deployment on research vessels, ships of opportunity, and large buoys

4-H forestry handbook

Cooperative Extension Work in Agriculture and Home Economics, University of Missouri, College of Agriculture and the United States Department of Agriculture cooperating."January, 1953."Title from cover

Automatic signal range selector for metering devices Patent

Voltage range selection apparatus for sensing and applying voltages to electronic instruments without loading signal sourc

Stability of Filters for the Navier-Stokes Equation

Data assimilation methodologies are designed to incorporate noisy observations of a physical system into an underlying model in order to infer the properties of the state of the system. Filters refer to a class of data assimilation algorithms designed to update the estimation of the state in a on-line fashion, as data is acquired sequentially. For linear problems subject to Gaussian noise filtering can be performed exactly using the Kalman filter. For nonlinear systems it can be approximated in a systematic way by particle filters. However in high dimensions these particle filtering methods can break down. Hence, for the large nonlinear systems arising in applications such as weather forecasting, various ad hoc filters are used, mostly based on making Gaussian approximations. The purpose of this work is to study the properties of these ad hoc filters, working in the context of the 2D incompressible Navier-Stokes equation. By working in this infinite dimensional setting we provide an analysis which is useful for understanding high dimensional filtering, and is robust to mesh-refinement. We describe theoretical results showing that, in the small observational noise limit, the filters can be tuned to accurately track the signal itself (filter stability), provided the system is observed in a sufficiently large low dimensional space; roughly speaking this space should be large enough to contain the unstable modes of the linearized dynamics. Numerical results are given which illustrate the theory. In a simplified scenario we also derive, and study numerically, a stochastic PDE which determines filter stability in the limit of frequent observations, subject to large observational noise. The positive results herein concerning filter stability complement recent numerical studies which demonstrate that the ad hoc filters perform poorly in reproducing statistical variation about the true signal

A Three-Dimensional Dynamic Supramolecular "Sticky Fingers" Organic Framework.

Engineering high-recognition host-guest materials is a burgeoning area in basic and applied research. The challenge of exploring novel porous materials with advanced functionalities prompted us to develop dynamic crystalline structures promoted by soft interactions. The first example of a pure molecular dynamic crystalline framework is demonstrated, which is held together by means of weak "sticky fingers" van der Waals interactions. The presented organic-fullerene-based material exhibits a non-porous dynamic crystalline structure capable of undergoing single-crystal-to-single-crystal reactions. Exposure to hydrazine vapors induces structural and chemical changes that manifest as toposelective hydrogenation of alternating rings on the surface of the [60]fullerene. Control experiments confirm that the same reaction does not occur when performed in solution. Easy-to-detect changes in the macroscopic properties of the sample suggest utility as molecular sensors or energy-storage materials