Ultrafast dynamics in the presence of antiferromagnetic correlations in electron-doped cuprate La2−x_{2-x}Cex_xCuO4±δ_{4\pm\delta}

We used femtosecond optical pump-probe spectroscopy to study the photoinduced change in reflectivity of thin films of the electron-doped cuprate La$_{2-x}$Ce$_x$CuO$_4$ (LCCO) with dopings of x$=$0.08 (underdoped) and x$=$0.11 (optimally doped). Above T$_c$, we observe fluence-dependent relaxation rates which onset at a similar temperature that transport measurements first see signatures of antiferromagnetic correlations. Upon suppressing superconductivity with a magnetic field, it is found that the fluence and temperature dependence of relaxation rates is consistent with bimolecular recombination of electrons and holes across a gap (2$\Delta_{AF}$) originating from antiferromagnetic correlations which comprise the pseudogap in electron-doped cuprates. This can be used to learn about coupling between electrons and high-energy ($\omega>2\Delta_{AF}$) excitations in these compounds and set limits on the timescales on which antiferromagnetic correlations are static

Analytical Rebridging Monte Carlo: Application to cis/trans Isomerization in Proline-Containing, Cyclic Peptides

We present a new method, the analytical rebridging scheme, for Monte Carlo simulation of proline-containing, cyclic peptides. The cis/trans isomerization is accommodated by allowing for two states of the amide bond. We apply our method to five peptides that have been previously characterized by NMR methods. Our simulations achieve effective equilibration and agree well with experimental data in all cases. We discuss the importance of effective equilibration and the role of bond flexibility and solvent effects on the predicted equilibrium properties.Comment: 29 pages, 8 PostScript figures, LaTeX source. to appear in J. Chem. Phys., 199

A case of contusion of the axillary artery

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Wetland Resources of Eastern South Dakota

The mere mention of the word wetland in coffee shops and other gathering places on the prairies today brings out emotions and opinions that run the gamut from saving them all to draining them all. To some people, what we do with wetlands has been, and still is, a personal choice, a matter of exercising individual rights on private property. To others, wetlands are community resources that provide values that touch all of society. They contend that what is done to and about wetlands is a community decision regardless of ownership. Herein lies the controversy we have experienced over wetlands on the prairie-a resource which provides societal benefits, yet is privately owned. The owners of prairie wetlands, like landowners everywhere, are possessive of their rights and options to make the most of their investment or inheritance. They jealously guard their right to detennine the fate of the resources they own. Those interested in the public benefits of wetlands are equally motivated to ensure that wetland values are defended. Where this debate will lead is a matter of speculation. Before landscape-level decisions about land use, and in this case wetland use, can adequately be addressed, all parties involved will be better equipped to defend their position if they know the extent of the resource, where it is, factors of quality, and something of the social interests in this resource. Dr. Johnson and Dr. Higgins have done a masterful job of bringing together a state-of-the-art inventory of eastern South Dakota\u27s wetland resources and have made comparisons of several factors of the nature of the wetlands found in the glaciated region of South Dakota. They have also included in this paper a history of some of the social and economic issues surrounding wetlands on the prairies, wetlands use and misuse, and the issues that, make up the wetland controversies of the region. Wetland Resources of Eastern South Dakota is an essential reference for those concerned about the future of wetlands and wetland policy in South Dakota and beyond. Armed with the information contained in this publication, decision makers at all levels will be informed on the number, size, and distribution of wetlands in eastern South Dakota. People working on the landscape level or on an individual ownership level will find this unique publication a valuable tool. [Forward by Carl R. Madsen, U.S. Fish and Wildlife Service]https://openprairie.sdstate.edu/nrm_book/1004/thumbnail.jp

The distribution of extremal points of Gaussian scalar fields

We consider the signed density of the extremal points of (two-dimensional) scalar fields with a Gaussian distribution. We assign a positive unit charge to the maxima and minima of the function and a negative one to its saddles. At first, we compute the average density for a field in half-space with Dirichlet boundary conditions. Then we calculate the charge-charge correlation function (without boundary). We apply the general results to random waves and random surfaces. Furthermore, we find a generating functional for the two-point function. Its Legendre transform is the integral over the scalar curvature of a 4-dimensional Riemannian manifold.Comment: 22 pages, 8 figures, corrected published versio

An Annotated Bibliography: Published Articles (1861-1998) About the Wild Mammals of South Dakota

Our goal in compiling this bibliography was to locate every published article with a connection to any wild South Dakota mammal. However, we understood from the start that this goal would be unattainable. Consequently, this collection can provide only a point of origin to readers interested in obtaining published studies (popular and scientific) about the wild mammals of South Dakota

Statistical Mechanics of Vibration-Induced Compaction of Powders

We propose a theory which describes the density relaxation of loosely packed, cohesionless granular material under mechanical tapping. Using the compactivity concept we develope a formalism of statistical mechanics which allows us to calculate the density of a powder as a function of time and compactivity. A simple fluctuation-dissipation relation which relates compactivity to the amplitude and frequency of a tapping is proposed. Experimental data of E.R.Nowak et al. [{\it Powder Technology} 94, 79 (1997) ] show how density of initially deposited in a fluffy state powder evolves under carefully controlled tapping towards a random close packing (RCP) density. Ramping the vibration amplitude repeatedly up and back down again reveals the existence of reversible and irreversible branches in the response. In the framework of our approach the reversible branch (along which the RCP density is obtained) corresponds to the steady state solution of the Fokker-Planck equation whereas the irreversible one is represented by a superposition of "excited states" eigenfunctions. These two regimes of response are analyzed theoretically and a qualitative explanation of the hysteresis curve is offered.Comment: 11 pages, 2 figures, Latex. Revised tex

Meta-analysis of continuous outcomes: using pseudo IPD created from aggregate data to adjust for baseline imbalance and assess treatment-by-baseline modification.

Meta-analysis of individual participant data (IPD) is considered the "gold-standard" for synthesizing clinical study evidence. However, gaining access to IPD can be a laborious task (if possible at all) and in practice only summary (aggregate) data are commonly available. In this work we focus on meta-analytic approaches of comparative studies where aggregate data are available for continuous outcomes measured at baseline (pre-treatment) and follow-up (post-treatment). We propose a method for constructing pseudo individual baselines and outcomes based on the aggregate data. These pseudo IPD can be subsequently analysed using standard analysis of covariance (ANCOVA) methods. Pseudo IPD for continuous outcomes reported at two timepoints can be generated using the sufficient statistics of an ANCOVA model i.e., the mean and standard deviation at baseline and follow-up per group, together with the correlation of the baseline and follow-up measurements. Applying the ANCOVA approach, which crucially adjusts for baseline imbalances and accounts for the correlation between baseline and change scores, to the pseudo IPD results in identical estimates to the ones obtained by an ANCOVA on the true IPD. In addition, an interaction term between baseline and treatment effect can be added. There are several modelling options available under this approach, which makes it very flexible. Methods are exemplified using reported data of a previously published IPD metaanalysis of 10 trials investigating the effect of antihypertensive treatments on systolic blood pressure, leading to identical results compared with the true IPD analysis and of a meta-analysis of fewer trials, where baseline imbalance occurred. This article is protected by copyright. All rights reserved

An examination of the effects of self-regulatory focus on the perception of the media richness: the case of email

Communication is a key element in organizations’ business success. The media richness theory and the channel expansion theory are two of the most influential theories regarding the selection and use of communication media in organizations; however, literature has focused little on the effects of self-regulation by managers and employees in these theories. To analyze these topics, this study develops an empirical investigation by gathering data from 600 managers and employees using a questionnaire. The results suggest that the perception of media richness is positively affected when the individual shows a promotion focus or strategy.Peer ReviewedPostprint (author’s final draft

Monitoring Subsurface Drainage Flow at Remote Locations

Laboratory evaluations and field results are presented for a slotted weir used to measure discharge from subsurface drains. The head–discharge curve for the vertical slot is a simple power function with an exponent of 1.5. There was excellent agreement (r2 \u3e 0.99 and 1:1 slope) between predicted and observed discharge in laboratory testing of 12 test weirs representing five slot widths. The primary advantages of the vertical slot weir are its simplicity, ease of maintenance, and ability to measure small flow rates. Disadvantages include a tendency for the slot to close a small amount over time as a result of creep when using a PVC pipe and the possibility for material to become clogged in the slot. The use of a spacer in the slot eliminated the tendency for the slot to close