Community at the Courts: Social and Community Interactions at Public Basketball Courts

Based on over 60 informal interviews conducted at two public basketball courts, this study utilizes grounded theory to trace class- and race-based differences in the social interactions occurring at both parks. By comparing social interactions between a white, middle class basketball court, and a black, lower class basketball court, I argue that social engagement is not be declining for all segments of society as some theorists suggest. Moreover, I argue that the relationships forged at the basketball court in a predominantly black, working-class neighborhood prove to be more meaningful and have deeper benefits than those forged at a basketball court in a white, middle-class neighborhood. I show that public places serve as a source of social status for participants of pick-up basketball and that social status stemming from pick-up basketball varies in importance based on the socioeconomic status of the participants. Further, I contend that public places in low-income neighborhoods can serve as a vehicle for establishing social networks in the surrounding community, affirming and maintaining status, and realizing personal fulfillment

Study of the state-of-the-art of the hermetic seals for secondary alkaline spacecraft cells Quarterly report, Sep. 20 - Dec. 20, 1967

Manufacturing methods, cost estimates, advantages, and limitations of various types of hermetic seals for secondary alkaline spacecraft cell

Stress and Health in College Students

Research has demonstrated that college students experience stress from sources such as poor self-care habits, educational demands, daily hassles, and perceived control over stressful situations. The present study examined perceived stress, health habits, and daily hassles and uplifts among 135 college freshmen. We hypothesized that students with lower stress levels would be male, would have better self-care habits, would experience fewer minor medical health issues, would have significantly higher academic performance, and would experience fewer daily hassles and more daily uplifts than students who experienced high perceived stress. Strong support was obtained for the hypothesis that students with low perceived stress had better health habits. Students with low perceived stress also experienced significantly fewer hassles and more uplifts per month. There were not any significant effects of perceived stress on grade point average, minor medical issues, or gender. The results could help college freshmen adjust to challenges of college by helping them understand some of the effects of stress and benefits of reducing that stress.No embarg

Report of the Alumni Historian, 2007

4 p; ill.; 28 cm. Electronic reproduction. Original, 3 June 2007.The Alumni Historian recounts activities for FY2006-07: (1) publication of twenty-five DKE historical studies and administrative reports on the Cornell University DSpace site, (2) assembly of seventeen unpublished research notes, (3) tabulation of errata in previously released work, and (4) listing of several miscellaneous items

Chapter and Alumni Operations Handbook, 1988

11 p; tables; 28 cm. Electronic reproduction. Original, 11 November 1988.Reference data concerning the Delta Kappa Epsilon Fraternity, the Delta Chi Chapter of Delta Kappa Epsilon at Cornell University, the Delta Chi Association and Cornell University are tabulated

Clonal Interference, Multiple Mutations, and Adaptation in Large Asexual Populations

Two important problems affect the ability of asexual populations to accumulate beneficial mutations, and hence to adapt. First, clonal interference causes some beneficial mutations to be outcompeted by more-fit mutations which occur in the same genetic background. Second, multiple mutations occur in some individuals, so even mutations of large effect can be outcompeted unless they occur in a good genetic background which contains other beneficial mutations. In this paper, we use a Monte Carlo simulation to study how these two factors influence the adaptation of asexual populations. We find that the results depend qualitatively on the shape of the distribution of the effects of possible beneficial mutations. When this distribution falls off slower than exponentially, clonal interference alone reasonably describes which mutations dominate the adaptation, although it gives a misleading picture of the evolutionary dynamics. When the distribution falls off faster than exponentially, an analysis based on multiple mutations is more appropriate. Using our simulations, we are able to explore the limits of validity of both of these approaches, and we explore the complex dynamics in the regimes where neither are fully applicable.Comment: 24 pages, 5 figure

Non-Equilibrium Modeling of the Fe XVII 3C/3D ratio for an Intense X-ray Free Electron Laser

We present a review of two methods used to model recent LCLS experimental results for the 3C/3D line intensity ratio of Fe XVII (Bernitt et al. 2012), the time-dependent collisional-radiative method and the density-matrix approach. These are described and applied to a two-level atomic system excited by an X-ray free electron laser. A range of pulse parameters is explored and the effects on the predicted Fe XVII 3C and 3D line intensity ratio are calculated. In order to investigate the behavior of the predicted line intensity ratio, a particular pair of A-values for the 3C and 3D transitions was chosen (2.22 $\times$ 10$^{13}$ s$^{-1}$ and 6.02 $\times$ 10$^{12}$ s$^{-1}$ for the 3C and 3D, respectively), but our conclusions are independent of the precise values. We also reaffirm the conclusions from Oreshkina et al.(2014, 2015): the non-linear effects in the density matrix are important and the reduction in the Fe XVII 3C/3D line intensity ratio is sensitive to the laser pulse parameters, namely pulse duration, pulse intensity, and laser bandwidth. It is also shown that for both models the lowering of the 3C/3D line intensity ratio below the expected time-independent oscillator strength ratio has a significant contribution due to the emission from the plasma after the laser pulse has left the plasma volume. Laser intensities above $\sim 1\times 10^{12}$ W/cm$^{2}$ are required for a reduction in the 3C/3D line intensity ratio below the expected time independent oscillator strength ratio