The Impact of After-School Programs That Promote Personal and Social Skills

The first of several reports to come from CASEL's major meta-analysisproject. Conducted in collaboration with Joseph Durlak of Loyola Universityand funded by the W.T. Grant Foundation, this first report describes thestrong positive effects after-school programs can have, and the conditionsneeded to realize these benefits

From Conflict to Collaboration: Exploring Influences on Community Well-Being

Decades after the Timber Wars, land management agencies continue to redefine approaches to forest restoration and management, with impacts for Western forest dependent communities. To better understand this evolving dynamic, we examined the recent history of a rural forest community in the northern Sierra Nevada against the backdrop of changing perspectives on and relationships to resource use, industry, and forest management. Guided by community priorities distilled from interview data, we examine the transition from the Timber Wars to collaborative forest management through the rise of area collaboratives. The success of this work and its potential to genuinely improve community well-being remains to be seen but a notable shift has begun. With this paper we aim to advance understanding of the transition from the Timber Wars to community-based collaborative efforts, and what this means for rural forest communities

Transport properties of heterogeneous materials derived from Gaussian random fields: Bounds and Simulation

We investigate the effective conductivity ($\sigma_e$) of a class of amorphous media defined by the level-cut of a Gaussian random field. The three point solid-solid correlation function is derived and utilised in the evaluation of the Beran-Milton bounds. Simulations are used to calculate $\sigma_e$ for a variety of fields and volume fractions at several different conductivity contrasts. Relatively large differences in $\sigma_e$ are observed between the Gaussian media and the identical overlapping sphere model used previously as a `model' amorphous medium. In contrast $\sigma_e$ shows little variability between different Gaussian media.Comment: 15 pages, 14 figure

Apparent Fractality Emerging from Models of Random Distributions

The fractal properties of models of randomly placed $n$-dimensional spheres ($n$=1,2,3) are studied using standard techniques for calculating fractal dimensions in empirical data (the box counting and Minkowski-sausage techniques). Using analytical and numerical calculations it is shown that in the regime of low volume fraction occupied by the spheres, apparent fractal behavior is observed for a range of scales between physically relevant cut-offs. The width of this range, typically spanning between one and two orders of magnitude, is in very good agreement with the typical range observed in experimental measurements of fractals. The dimensions are not universal and depend on density. These observations are applicable to spatial, temporal and spectral random structures. Polydispersivity in sphere radii and impenetrability of the spheres (resulting in short range correlations) are also introduced and are found to have little effect on the scaling properties. We thus propose that apparent fractal behavior observed experimentally over a limited range may often have its origin in underlying randomness.Comment: 19 pages, 12 figures. More info available at http://www.fh.huji.ac.il/~dani

Posterior lung herniation after a coughing spell: a case report

Lung hernias are rare, occurring most commonly after trauma or surgery. Spontaneous lung hernias are even rarer and have only been reported as occurring anteriorly. We present a 72-year-old male who developed a spontaneous posterior lung hernia after a severe coughing episode. We describe the evaluation and surgical management of this unusual condition and provide a brief review of the literature