Early Access: Elementary School Outcomes for Arkansas Better Chance Public Pre-Kindergarten Participants

Public pre-Kindergarten programs are frequently promoted as promising early interventions for at-risk students, as they can equip 3- and 4-year-olds with the cognitive, behavioral, and social skills necessary for success in Kindergarten and beyond. The Arkansas Better Chance (ABC) program provides low-income and at-risk Arkansas students with tuition-free pre-K opportunities in school districts across the state. The current analysis describes the 3rd and 5th grade outcomes of students who enroll in ABC pre-K programs in Arkansas public schools. In an attempt to understand how well these programs are serving students, we follow four cohorts of program participants through elementary school, and we compare their math and reading achievement test scores to those of similar peers who did not attend ABC programs. We find ABC pre-K participants are more likely to fall into demographic groups that are considered at-risk for low academic performance, and that ABC students outperform similar peers on math and reading achievement tests in 3rd grade in three of four cohorts. These findings suggest that this program has the potential to set students up for lasting academic success

Contrasting phylogeographic structures between freshwater lycopods and angiosperms in the British Isles

Aquatic plants face many novel challenges compared to their terrestrial counterparts. The habitat they occupy is typically highly fragmented, with isolated water bodies surrounded by swathes of “dry desert”. This can result in reduced gene flow, inbreeding, and potentially local extinction. The level of gene flow and degree of genetic structure in these species is also likely to be influenced by the mating system they adopt. To test this hypothesis we compare the phylogeographic structure of two freshwater plants in the British Isles, the largely clonal angiosperm Littorella uniflora, and the heterosporous lycopod Isoetes lacustris. We sampled both plants from lakes where they co-occur, and used restriction site-associated DNA sequencing (RAD-Seq) to infer their relationships. Genetic structure among lakes is higher in the angiosperm, which we associate with reduced sexual reproduction, and hence lower levels of gene flow between lakes. Furthermore, we found evidence of lineage-specific association to certain lake nutrient types in L. uniflora, which might result from environmental filtering of specific ecotypes. Overall, we conclude that the reproductive system of lycopods, which is less specialized to terrestrial conditions, provides an advantage following the secondary colonization of aquatic habitats by enabling frequent genetic exchanges between populations and potentially facilitating faster adaptation

Demonstrating the utility of a drought termination framework: prospects for groundwater level recovery in England and Wales in 2018 or beyond

During prolonged droughts, information is needed about when and how the extreme event is likely to terminate. A drought termination framework based on historical data comprising current rate and historical ensemble approaches is presented here for assessing the prospects of groundwater level recovery. The current rate approach is evaluated across all initialisation months in the historical record and provides reasonable estimates for the duration of recovery from relatively severe groundwater level deficiencies in some slowly responding boreholes. The utility of the framework is demonstrated through a near-real-time application to 30 groundwater boreholes in England and Wales from October 2017 onwards. Recovery during winter 2017/18 was considered unlikely, as some aquifers required increases in groundwater levels that have occurred seldom, if ever before, in long historical records. Data to February 2018 confirmed the success of these pre-winter outlooks. Recovery by mid- to late-2018 or beyond was more likely; slow rates of recovery by October 2017 and increasing return periods of effective rainfall required for recovery over timeframes in the summer half-year underlined the importance of winter rainfall and suggested that the historical ensemble may underestimate the duration of recovery. There was moderate confidence for a delay in recovery beyond the end of 2018 in some slowly responding Chalk boreholes in south-central and eastern England. There is considerable potential for the transferability of the drought termination framework beyond the UK wherever there are sufficient historical data. The two approaches provide limited information in distinctly different circumstances and their relevance and value may differ in space and time, suggesting their complimentary use as the most robust way to incorporate information on the prospects for groundwater level recovery into existing seasonal forecasting services, supporting decision-making by water managers during prolonged droughts

High-Temperature Series Analyses of the Classical Heisenberg and XY Model

Although there is now a good measure of agreement between Monte Carlo and high-temperature series expansion estimates for Ising ($n=1$) models, published results for the critical temperature from series expansions up to 12{\em th} order for the three-dimensional classical Heisenberg ($n=3$) and XY ($n=2$) model do not agree very well with recent high-precision Monte Carlo estimates. In order to clarify this discrepancy we have analyzed extended high-temperature series expansions of the susceptibility, the second correlation moment, and the second field derivative of the susceptibility, which have been derived a few years ago by L\"uscher and Weisz for general $O(n)$ vector spin models on $D$-dimensional hypercubic lattices up to 14{\em th} order in $K \equiv J/k_B T$. By analyzing these series expansions in three dimensions with two different methods that allow for confluent correction terms, we obtain good agreement with the standard field theory exponent estimates and with the critical temperature estimates from the new high-precision MC simulations. Furthermore, for the Heisenberg model we reanalyze existing series for the susceptibility on the BCC lattice up to 11{\em th} order and on the FCC lattice up to 12{\em th} order.Comment: 15 pages, Latex, 2 PS figures not included. FUB-HEP 18/92 and HLRZ 76/9

Finite-Size Scaling Study of the Three-Dimensional Classical Heisenberg Model

We use the single-cluster Monte Carlo update algorithm to simulate the three-dimensional classical Heisenberg model in the critical region on simple cubic lattices of size $L^3$ with $L=12, 16, 20, 24, 32, 40$, and $48$. By means of finite-size scaling analyses we compute high-precision estimates of the critical temperature and the critical exponents, using extensively histogram reweighting and optimization techniques. Measurements of the autocorrelation time show the expected reduction of critical slowing down at the phase transition. This allows simulations on significantly larger lattices than in previous studies and consequently a better control over systematic errors in finite-size scaling analyses.Comment: 9 pages, FUB-HEP 9/92, HLRZ Preprint 56/92, August 199

Notes from the field: Lessons learned from using ecosystem service approaches to inform real-world decisions

While there have been rapid advances in assessments of biodiversity and ecosystem services (BES), a critical remaining challenge is how to move from scientific knowledge to real-world decision making. We offer 6 lessons from our experiences applying new approaches and tools for quantifying BES in 20 pilot demonstrations: (1) Applying a BES approach is most effective in leading to policy change as part of an iterative science-policy process; (2) simple ecological production function models have been useful in a diverse set of decision contexts, across a broad range of biophysical, social, and governance systems. Key limitations of simple models arise at very small scales, and in predicting specific future BES values; (3) training local experts in the approaches and tools is important for building local capacity, ownership, trust, and long-term success; (4) decision makers and stakeholders prefer to use a variety of BES value metrics, not only monetary values; (5) an important science gap exists in linking changes in BES to changes in livelihoods, health, cultural values, and other metrics of human wellbeing; and (6) communicating uncertainty in useful and transparent ways remains challenging

The Safe and Efficient Development of Offshore Transboundary Hydrocarbons: Best Practices from the North Sea and Their Application to the Gulf of Mexico

Offshore hydrocarbon resources have been developed for many decades, and with technology improvements, many fields which were once impossible to develop, are now economically and technologically feasible. This has led to a growing difficulty in determining the legislative and regulatory framework for resources that straddle the recognized borders between two states. In this paper, we examine a successful framework agreement governing the transboundary resources between the United Kingdom (“U.K.”) and Norway in the North Sea, and the agreement between the United States and Mexico governing the Gulf of Mexico. Following the 2013 Energy Reform, the Mexican energy sector has been revitalized, leading to greater exploration, development, and production than ever before. This means that in the near future transboundary resources may be licensed for production, bringing the issues highlighted in this paper to the attention of multiple government and international entities. This paper seeks to recommend improvements to the transboundary framework in the Gulf of Mexico based on the successful framework agreement utilized in the North Sea. This paper begins by introducing international law for offshore resources in Part II. Part III discusses the offshore regulatory regimes in the U.K. and Norway, analyzing how the two states have successfully used bilateral agreements to facilitate cooperation regarding effective exploitation and apportionment of costs from cross-boundary offshore oil and gas projects in the North Sea. Part IV discusses the offshore regulatory regimes in the United States and Mexico and analyzes the current transboundary agreement in place for the Gulf of Mexico. Part V compares the transboundary agreement governing the North Sea and the same governing the Gulf of Mexico. We highlight the major differences in the agreements and suggest changes to the Gulf of Mexico agreement based on the successful North Sea agreement. Finally, this paper concludes and provides key policy recommendations to improve the rules and regulations surrounding the exploitation of transboundary hydrocarbons in the Gulf of Mexico

Appalachian Music: Discussing the Top Ten

Convenor Sandy Ballard, Editor of Appalachian Journal, Appalachian State University Moderators Mark Freed, Cultural Resources Coordinator for the town of Boone, NC, and teacher of Appalachian Music, Appalachian State University. Guest editor of Appalachian Music edition of Appalachian Journal. Trevor McKenzie, archivist, W. L. Eury Appalachian Collection, Appalachian State University. Guest editor of Appalachian Music edition of Appalachian Journal

Maximum-likelihood estimation of lithospheric flexural rigidity, initial-loading fraction, and load correlation, under isotropy

Topography and gravity are geophysical fields whose joint statistical structure derives from interface-loading processes modulated by the underlying mechanics of isostatic and flexural compensation in the shallow lithosphere. Under this dual statistical-mechanistic viewpoint an estimation problem can be formulated where the knowns are topography and gravity and the principal unknown the elastic flexural rigidity of the lithosphere. In the guise of an equivalent "effective elastic thickness", this important, geographically varying, structural parameter has been the subject of many interpretative studies, but precisely how well it is known or how best it can be found from the data, abundant nonetheless, has remained contentious and unresolved throughout the last few decades of dedicated study. The popular methods whereby admittance or coherence, both spectral measures of the relation between gravity and topography, are inverted for the flexural rigidity, have revealed themselves to have insufficient power to independently constrain both it and the additional unknown initial-loading fraction and load-correlation fac- tors, respectively. Solving this extremely ill-posed inversion problem leads to non-uniqueness and is further complicated by practical considerations such as the choice of regularizing data tapers to render the analysis sufficiently selective both in the spatial and spectral domains. Here, we rewrite the problem in a form amenable to maximum-likelihood estimation theory, which we show yields unbiased, minimum-variance estimates of flexural rigidity, initial-loading frac- tion and load correlation, each of those separably resolved with little a posteriori correlation between their estimates. We are also able to separately characterize the isotropic spectral shape of the initial loading processes.Comment: 41 pages, 13 figures, accepted for publication by Geophysical Journal Internationa

Solar Particle Acceleration at Reconnecting 3D Null Points

Context: The strong electric fields associated with magnetic reconnection in solar flares are a plausible mechanism to accelerate populations of high energy, non-thermal particles. One such reconnection scenario occurs at a 3D magnetic null point, where global plasma flows give rise to strong currents in the spine axis or fan plane. Aims: To understand the mechanism of charged particle energy gain in both the external drift region and the diffusion region associated with 3D magnetic reconnection. In doing so we evaluate the efficiency of resistive spine and fan models for particle acceleration, and find possible observables for each. Method: We use a full orbit test particle approach to study proton trajectories within electromagnetic fields that are exact solutions to the steady and incompressible magnetohydrodynamic equations. We study single particle trajectories and find energy spectra from many particle simulations. The scaling properties of the accelerated particles with respect to field and plasma parameters is investigated. Results: For fan reconnection, strong non-uniform electric drift streamlines can accelerate the bulk of the test particles. The highest energy gain is for particles that enter the current sheet, where an increasing "guide field" stabilises particles against ejection. The energy is only limited by the total electric potential energy difference across the fan current sheet. The spine model has both slow external electric drift speed and weak energy gain for particles reaching the current sheet. Conclusions: The electromagnetic fields of fan reconnection can accelerate protons to the high energies observed in solar flares, gaining up to 0.1 GeV for anomalous values of resistivity. However, the spine model, which gave a harder energy spectrum in the ideal case, is not an efficient accelerator after pressure constraints in the resistive model are included.Comment: 15 pages, 14 figures. Submitted to Astronomy and Astrophysic