Curriculum for the IXth grade of a small Massachusetts high school based on a study of current practices and individual differences

Thesis (Ed.M.)--Boston University, 1938. This item was digitized by the Internet Archive

Satellite data for surface-mine inventory

To determine the feasibility of satellite data for surface-mine inventory, particularly as it applies to coal, a case study was conducted in Maryland. A band-ratio method was developed to measure disturbed surface areas, and it proved to be extendible both temporally and geographically. This method was used to measure area changes in the region over three time periods from September 1972 through July 1974 and to map the entire two-county area for 1973. For mines ranging between 31 and 244 acres (12 to 98 hectares) the measurement accuracy of total affected acreage was determined to be 92%. Mines of 120 acres (50 hectares) and larger were measured with greater accuracy, some within one percent of the actual area. The ability to identify, classify, and measure strip-mine surfaces in a two-county area (1,541 square kilometers - 595 square miles) of western Maryland was demonstrated through the use of computer processing. On the basis of these results the use of LANDSAT satellite data and multilevel sampling of aircraft and field verification inspections, multispectral analysis of digital data is shown to be an effective, rapid, and accurate means of monitoring the surface mining cycle

Production of heralded pure single photons from imperfect sources using cross phase modulation

Realistic single-photon sources do not generate single photons with certainty. Instead they produce statistical mixtures of photons in Fock states $\ket{1}$ and vacuum (noise). We describe how to eliminate the noise in the output of the sources by means of another noisy source or a coherent state and cross phase modulation (XPM). We present a scheme which announces the production of pure single photons and thus eliminates the vacuum contribution. This is done by verifying a XPM related phase shift with a Mach-Zehnder interferometer.Comment: 8 pages, 8 EPS figures, RevTeX4. Following changes have been made in v.3: Title and abstract slightly changed; numerous minor revisions and clarifications within the text; an appendix with three new figures has been added. In version v4 we have included a supplementary analysis of our scheme that takes into account absorption losses. Our analysis is heuristic and based on a phenomenological model, which is independent of the physical realization of the proposed scheme. We have estimated upper bounds up to which absorption losses can be tolerated, so as our scheme to improve the efficiency of single photon sources still works. Accepted for publication in Phys. Rev.

Mental Disorders, Comorbidity, and Suicidal Behavior: Results from the National Comorbidity Survey Replication

Mental disorders are among the strongest predictors of suicide attempts. However, little is known about which disorders are uniquely associated with suicidal behavior due to high levels of psychiatric comorbidity. We examined the unique associations between individual disorders and subsequent suicidal behavior (suicide ideation, plans, and attempts) using data from the National Comorbidity Survey Replication, a nationally representative household survey of 9,282 US adults. Results revealed that approximately 80% of suicide attempters in the US have a temporally prior mental disorder. Anxiety, mood, impulse-control, and substance disorders all significantly predict subsequent suicide attempts in bivariate analyses (odds ratios=2.7-6.7); however, these associations decrease substantially in multivariate analyses controlling for comorbidity (odds ratios=1.5-2.3) but remain statistically significant in most cases. Disaggregation of the observed effects reveals that depression predicts suicide ideation, but not suicide plans or attempts among those with ideation. Instead, disorders characterized by severe anxiety/agitation (e.g., PTSD) and poor impulse-control (e.g., conduct disorder, substance disorders) predict which suicide ideators go on to make a plan or attempt. These results advance understanding of the unique associations between mental disorders and different forms of suicidal behavior. Future research must further delineate the mechanisms through which people come to think about suicide and progress from suicidal thoughts to attempts.Psycholog

Equitable Conversion in Washington: The Doctrine That Dares Not Speak Its Name

Since the 1925 decision of Ashford v. Reese, Washington has had the distinction of being the only American jurisdiction totally, albeit implicitly, to reject the doctrine of equitable conversion. Ashford was overruled in 1977, in a remarkable opinion which simultaneously, and explicitly, rejected the doctrine of equitable conversion, thus maintaining Washington\u27s unique status with respect to that doctrine. But the opinion failed to provide a substitute for either the rule of Ashford or the contrary doctrine of equitable conversion, both of which it emphatically abjured. The result is an unbroken line of Washington cases consistent with only one rule of law-the doctrine of equitable conversion. The effect of the opinion is thus de jure rejection and de facto adoption of equitable conversion. This article will analyze the process by which Washington has managed to achieve substantial conformity with the majority of American jurisdictions, while resolutely maintaining a unique stance

Exploring Planets with Directed Aerial Robot Explorers

Global Aerospace Corporation (GAC) is developing a revolutionary system architecture for exploration of planetary atmospheres and surfaces from atmospheric altitudes. The work is supported by the NASA Institute for Advanced Concepts (NIAC). The innovative system architecture relies upon the use of Directed Aerial Robot Explorers (DAREs), which essentially are long-duration-flight autonomous balloons with trajectory control capabilities that can deploy swarms of miniature probes over multiple target areas. Balloon guidance capabilities will offer unprecedented opportunities in high-resolution, targeted observations of both atmospheric and surface phenomena. Multifunctional microprobes will be deployed from the balloons once over the target areas, and perform a multitude of functions, such as atmospheric profiling or surface exploration, relaying data back to the balloons or an orbiter. This architecture will enable low-cost, low-energy, long-term global exploration of planetary atmospheres and surfaces. This paper focuses on a conceptual analysis of the DARE architecture capabilities and science applications for Venus, Titan and Jupiter. Preliminary simulations with simplified atmospheric models show that a relatively small trajectory control wing can enable global coverage of the atmospheres of Venus and Titan by a single balloon over a 100-day mission. This presents unique opportunities for global in situ sampling of the atmospheric composition and dynamics, atmospheric profiling over multiple sites with small dropsondes and targeted deployment of surface microprobes. At Jupiter, path guidance capabilities of the DARE platforms permits targeting localized regions of interest, such as "hot spots" or the Great Red Spot. A single DARE platform at Jupiter can sample major types of the atmospheric flows (zones and belts) over a 100-day mission. Observations by deployable probes would reveal if the differences exist in radiative, dynamic and compositional environments at these sites

Heralded single-photon generation using imperfect single-photon sources and a two-photon-absorbing medium

We propose a setup for a heralded, i.e. announced generation of a pure single-photon state given two imperfect sources whose outputs are represented by mixtures of the single-photon Fock state $\ket{1}$ with the vacuum $\ket{0}$. Our purification scheme uses beam splitters, photodetection and a two-photon-absorbing medium. The admixture of the vacuum is fully eliminated. We discuss two potential realizations of the scheme.Comment: 22 pages, 8 figures (LaTeX). In version v2 we have slightly modified our setup so as to increase the success probability of single-photon generation by a factor of two. In addition, in an appendix we discuss alternative realizations of single-photon generation without a Mach-Zehnder interferometer. Three new figures have been added. Version v3 is a revised version published in Phys. Rev. A. It contains numerous minor corrections and clarifications. A new figure has been added in order to clarify our convention regarding labelling the field modes. The action of the beam splitters in the Schroedinger picture is introduced. A new reference has been include

Equitable Conversion in Washington: The Doctrine That Dares Not Speak Its Name

Since the 1925 decision of Ashford v. Reese, Washington has had the distinction of being the only American jurisdiction totally, albeit implicitly, to reject the doctrine of equitable conversion. Ashford was overruled in 1977, in a remarkable opinion which simultaneously, and explicitly, rejected the doctrine of equitable conversion, thus maintaining Washington\u27s unique status with respect to that doctrine. But the opinion failed to provide a substitute for either the rule of Ashford or the contrary doctrine of equitable conversion, both of which it emphatically abjured. The result is an unbroken line of Washington cases consistent with only one rule of law-the doctrine of equitable conversion. The effect of the opinion is thus de jure rejection and de facto adoption of equitable conversion. This article will analyze the process by which Washington has managed to achieve substantial conformity with the majority of American jurisdictions, while resolutely maintaining a unique stance

Elastomeric micropillar arrays for the study of protrusive forces in hyphal invasion

Fungi and Oomycetes are microorganisms that can be pathogenic and grow invasively causing significant economic losses and diseases1. • These organisms grow by extending the cell at the tip. This involves turgor pressure, cell wall yielding and a dynamic cytoskeleton, giving rise to a protrusive force2,3. •A Lab-on-a-Chip platform, with integrated force sensor based on elastomeric micro-pillars, is allowing us to study the molecular mechanisms which enable the generation of protrusive force at the tip of invasively-growing hyphae. •A maximum force of 16 μN was measured for the oomycete Achlya bisexualis cultured on the chip