Two-Loop Bethe Logarithms

We calculate the two-loop Bethe logarithm correction to atomic energy levels in hydrogen-like systems. The two-loop Bethe logarithm is a low-energy quantum electrodynamic (QED) effect involving multiple summations over virtual excited atomic states. Although much smaller in absolute magnitude than the well-known one-loop Bethe logarithm, the two-loop analog is quite significant when compared to the current experimental accuracy of the 1S-2S transition: it contributes -8.19 and -0.84 kHz for the 1S and the 2S state, respectively. The two-loop Bethe logarithm has been the largest unknown correction to the hydrogen Lamb shift to date. Together with the ongoing measurement of the proton charge radius at the Paul Scherrer Institute its calculation will bring theoretical and experimental accuracy for the Lamb shift in atomic hydrogen to the level of 10^(-7).Comment: 4 pages, RevTe

Noticing for Equity to Sustain Multilingual Literacies

This department explores how teachers can sustain students’ multilingual literacies and reimagine literacy learning across multiple contexts in conversation with researchers, practitioners, and communities

Recognition map analysis and crop acreage estimation using Skylab EREP data

There are no author-identified significant results in this report

A TRANSLOG COST FUNCTION ANALYSIS OF U.S. AGRICULTURE: A DYNAMIC SPECIFICATION

This study has used an empirical approach developed by Urga and Walters (2003) to examine the implications of the short-run specification of the standard translog cost specification along with the possible implications of non-stationarity. We have estimated a dynamic translog cost specification complete with dynamic share equations for U.S. agriculture and compared it to the static, long-run specification. We found that the dynamic translog specification yielded more significant parameter estimates, and yielded results that are consistent with economic theory. In particular, the coefficient m (the adjustment cost parameter) determines the overall autoregressive structure of the model. The fact that its estimated value (0.36) is statistically different from zero at any conventional level of confidence indicates that the dynamic structure of the model is important. This finding illustrates the superiority of the short-run, dynamic specification over the static, long-run model.Agribusiness,

A Translog Cost Function Analysis of U.S. Agriculture: 1948-1999

This study examines the implications of the short-run specification of the standard, static translog cost function along with the possible implications of non-stationarity by estimating a dynamic translog cost specification complete with dynamic share equations for the U.S. using an empirical approach developed by Urga and Walters (2003). We compare the results of the static, long-run model with those of a dynamic, short-run error-correction model in terms of 1) significance of the parameter estimates, and 2) consistency with economic theory.Research Methods/ Statistical Methods,

Recognition map analysis and crop acreage estimation

There are no author-identified significant results in this report

Implications for teacher education as adult development

The authors believe that the issues addressed in this article will strongly impact the shape of integrated education in the future

On the Mass of M31

Recent work by several groups has established the properties of the dwarf satellites to M31. We reexamine the reported kinematics of this group employing a fresh technique we have developed previously. By calculating the distribution of a chi statistic (which we define in the paper) for the M31 system, we conclude that the total mass (disk plus halo) of the primary is unlikely to be as great as that of our own Milky Way. In fact the chi distribution for M31 indicates that, like NGC 3992, it does not have a massive halo. In contrast, the analysis of the satellites of NGC 1961 and NGC 5084 provides strong evidence for massive halos surrounding both spiral galaxies.Comment: To appear in MNRAS, 10 pages with 6 figure

Current Best Practices among Cultural Heritage Institutions when Dealing with Copyright Orphan Works and Analysis of Crowdsourcing Options

The purpose of this study is to establish the current state of best practices among Cultural Heritage Institutions (CHIs) when dealing with in-copyright orphan works in three countries: the United Kingdom, Netherlands and Italy. A baseline understanding of current practice provides a benchmark against which crowdsourcing (or any other proposal) to address the challenge posed by orphan works can be evaluated. The research team used a purposive sample to approach the ‘Big 3’ national libraries and film archives in each country, typically including the national library, the national archive and the national film archive. The researchers also aimed to include at least one institution from each jurisdiction that had used the EUIPO database, and one institution that digitized orphan works but opted not to use the database. 15 cultural institutions are included in the study. A semi-structured interview format was used to gather qualitative and quantitative data about the CHIs, their collections, their diligent search processes, the results of rights clearance for specific digitization projects, their thoughts on the potential of crowd-sourcing as a solution, and their views on the current legislative framework