Estimating the Payoff to Attending a More Selective College: An Application of Selection on Observables and Unobservables

There are many estimates of the effect of college quality on students' subsequent earnings. One difficulty interpreting past estimates, however, is that elite colleges admit students, in part, based on characteristics that are related to their earnings capacity. Since some of these characteristics are unobserved by researchers who later estimate wage equations, it is difficult to parse out the effect of attending a selective college from the students' pre-college characteristics. This paper uses information on the set of colleges at which students were accepted and rejected to remove the effect of unobserved characteristics that influence college admission. Specifically, we match students in the newly colleted College and Beyond (C&B) Data Set who were admitted to and rejected from a similar set of institutions, and estimate fixed effects models. As another approach to adjust for selection bias, we control for the average SAT score of the schools to which students applied using both the C&B and National Longitudinal Survey of the High School Class of 1972. We find that students who attended more selective colleges do not earn more than other students who were accepted and rejected by comparable schools but attended less selective colleges. However, the average tuition charged by the school is significantly related to the students' subsequent earnings. Indeed, we find a substantial internal rate of return from attending a more costly college. Lastly, the payoff to attending an elite college appears to be greater for students from more disadvantaged family backgrounds.

A Complete Scheme of Ionization Cooling for a Muon Collider

A complete scheme for production and cooling a muon beam for three specified muon colliders is presented. Parameters for these muon colliders are given. The scheme starts with the front end of a proposed neutrino factory that yields bunch trains of both muon signs. Emittance exchange cooling in slow helical lattices reduces the longitudinal emittance until it becomes possible to merge the trains into single bunches, one of each sign. Further cooling in all dimensions is applied to the single bunches in further slow helical lattices. Final transverse cooling to the required parameters is achieved in 50 T solenoids using high Tc superconductor at 4 K. Preliminary simulations of each element are presented.Comment: 3 pages, 6 figure

Annotated references on managing young forests in the Douglas-fir region

This bibliography lists selected references useful to the forester in managing young forests in the Douglas-fir region. The references pertain to those management activities that are carried on in the forest from stand regeneration until final harvest. Emphasis is on silvicultural, operational, and economic aspects of management, but social and ecological aspects are also included. The publications are those that a practicing forester in the Pacific Northwest should have in his library or should at least be aware of. Most publications listed can be obtained by writing to the author or the issuing agency. The general publications and proceedings cover a variety of subjects on forest management. For example, subjects such as economics, ecology, and operations, although not listed by subject, are covered in the proceedings. Spacing tests begun in 1925 at the Wind River Douglas-fir plantation by the Pacific Northwest Forest and Range Experiment Station with 1-1 seedlings are the oldest tests in the Pacific Northwest. They show trends in stand growth and development for spacings of 4 x 4, 5 x 5, 6 x 6, 8 x 8, 10 x 10, and 12 x 12 feet. Table 1 is a summary of that information periodically for the first 43 years. ' The levels-of-growing-stock cooperative study in Douglas-fir is in its early years. The publications describe the thinning regimes, the study areas, and the cooperators. During the next year, publications on several of the study areas will cover early response. The bibliography is not exhaustive, and the selection of publications is the sole responsibility of the author

Algorithm for prediction of tumour suppressor p53 affinity for binding sites in DNA

The tumour suppressor p53 is a transcription factor that binds DNA in the vicinity of the genes it controls. The affinity of p53 for specific binding sites relative to other DNA sequences is an inherent driving force for specificity, all other things being equal. We measured the binding affinities of systematically mutated consensus p53 DNA-binding sequences using automated fluorescence anisotropy titrations. Based on measurements of the effects of every possible single base-pair substitution of a consensus sequence, we defined the DNA sequence with the highest affinity for full-length p53 and quantified the effects of deviation from it on the strength of protein–DNA interaction. The contributions of individual nucleotides were to a first approximation independent and additive. But, in some cases we observed significant deviations from additivity. Based on affinity data, we constructed a binding predictor that mirrored the existing p53 consensus sequence definition. We used it to search for high-affinity binding sites in the genome and to predict the effects of single-nucleotide polymorphisms in these sites. Although there was some correlation between the Kd and biological function, the spread of the Kds by itself was not sufficient to explain the activation of different pathways by changes in p53 concentration alone

Investigating mechanisms of state localization in highly ionized dense plasmas

Producción CientíficaWe present experimental observations of Kβ emission from highly charged Mg ions at solid density, driven by intense x rays from a free electron laser. The presence of Kβ emission indicates the n=3 atomic shell is relocalized for high charge states, providing an upper constraint on the depression of the ionization potential. We explore the process of state relocalization in dense plasmas from first principles using finite-temperature density functional theory alongside a wave-function localization metric, and find excellent agreement with experimental results.This work has been supported by the Spanish Ministry of Science and Innovation under Research Grant No. PID2019-108764RB-I0