After the Bell: Youth Activity Engagement in Relation to Income and Metropolitan Status

In this brief, author Sarah E. Leonard uses data from the 2012 National Survey of Children’s Health to examine involvement in activities among youth ages 12–18 across income categories and metropolitan status in the hopes of informing policy aimed at attenuating inequalities in participation. While not a complete profile of youth activities, determining participation rates helps us understand what youth are doing in their out-of-school hours and how these activities vary by income and metropolitan status. The relationship between extracurricular participation, academic success, and well-being is potentially linked in complex ways, yet access to extracurricular activities and employment is growing more unequal, and as a result lower-income youth may be increasingly disadvantaged compared to middle- and upper-income children. She reports that higher-income youth are twice as likely to be employed and one-and-a-half times as likely to participate in extracurricular activities as their lower-income counterparts. More urban youth participate in extracurricular activities than rural youth, but rural youth are more likely to be employed than urban youth. The share of youth who are reading, using television, and using electronics is comparable across income groups, though lower-income youth report participating in these activities for longer hours than their higher-income counterparts. In conclusion, she suggests actions that policy makers and school systems could take to give adolescents--regardless of their income or metropolitan status--the opportunity to participate in and benefit from extracurricular activities

Ceramic backup ring prevents undesirable weld-metal buildup

Removable ceramic backup material butted against weld zone back prevents weld metal buildup at that site. Method is successful with manual tungsten-inert gas /TIG/ welding of 316 corrosion resistant steel /CRES/ pieces with 0.76 cm throat diameter and 1.57 cm pipe internal diameter

Parameter estimation in softmax decision-making models with linear objective functions

With an eye towards human-centered automation, we contribute to the development of a systematic means to infer features of human decision-making from behavioral data. Motivated by the common use of softmax selection in models of human decision-making, we study the maximum likelihood parameter estimation problem for softmax decision-making models with linear objective functions. We present conditions under which the likelihood function is convex. These allow us to provide sufficient conditions for convergence of the resulting maximum likelihood estimator and to construct its asymptotic distribution. In the case of models with nonlinear objective functions, we show how the estimator can be applied by linearizing about a nominal parameter value. We apply the estimator to fit the stochastic UCL (Upper Credible Limit) model of human decision-making to human subject data. We show statistically significant differences in behavior across related, but distinct, tasks.Comment: In pres

The Retention of Chicago's Arts Students in Comparative Perspective

Highlights:* 58 percent of Chicago arts-school alumni took up residence in the city within 5 years of the date of their last attendance. Of the regions compared in this report, only New York City has a greater portion of its arts-school alumni taking up residence in the city within 5 years, at 66 percent.* 51 percent of Chicago arts-school alumni were out-of-state applicants who came to Chicago and were still living in the city within five years of their last date of attendance. This is the second highest portion of out-of-state applicants taking up residence in the city of their alma mater. New York City's rate was highest at 54 percent.* Of arts-school alumni who searched for work, 38 percent of those attending school in Chicago obtained work prior to leaving their institution; 85 percent obtained work within a year. Alumni from other regions had similar experiences.*50 percent of Chicago's alumni reported that their first job or work experience was "closely related" to their arts-school training. However, alumni from institutions in Los Angeles County, Cleveland/Columbus and New York City reported higher rates of their first work experience being closely related to their arts training

Why multi-tracer surveys beat cosmic variance

Galaxy surveys that map multiple species of tracers of large-scale structure can improve the constraints on some cosmological parameters far beyond the limits imposed by a simplistic interpretation of cosmic variance. This enhancement derives from comparing the relative clustering between different tracers of large-scale structure. We present a simple but fully generic expression for the Fisher information matrix of surveys with any (discrete) number of tracers, and show that the enhancement of the constraints on bias-sensitive parameters are a straightforward consequence of this multi-tracer Fisher matrix. In fact, the relative clustering amplitudes between tracers are eigenvectors of this multi-tracer Fisher matrix. The diagonalized multi-tracer Fisher matrix clearly shows that while the effective volume is bounded by the physical volume of the survey, the relational information between species is unbounded. As an application, we study the expected enhancements in the constraints of realistic surveys that aim at mapping several different types of tracers of large-scale structure. The gain obtained by combining multiple tracers is highest at low redshifts, and in one particular scenario we analyzed, the enhancement can be as large as a factor of ~3 for the accuracy in the determination of the redshift distortion parameter, and a factor ~5 for the local non-Gaussianity parameter. Radial and angular distance determinations from the baryonic features in the power spectrum may also benefit from the multi-tracer approach.Comment: New references included; 9 pages, 9 figure

Alignment apparatus using a laser having a gravitationally sensitive cavity reflector

A description is given of a device for determining a true gravitational vertical. The apparatus is composed of a vertically disposed laser with a gravitationally sensitive lower regeneration reflector. The reflector enables an output beam to be developed only when the optical axis of the laser is disposed normal to the gravitationally sensitive reflective surface. In an alternative embodiment, the devices is combined with a servo system to provide a gravitationally stabilized horizontal platform