University of Nebraska–Lincoln

About: University of Nebraska–Lincoln is a education organization based out in Lincoln, Nebraska, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 28059 authors who have published 61544 publications receiving 2139104 citations. The organization is also known as: Nebraska & UNL.

A meta-analytic review of the effects of high stress on eyewitness memory.

Abstract: In the past 30 years researchers have examined the impact of heightened stress on the fidelity of eyewitness memory. Meta-analyses were conducted on 27 independent tests of the effects of heightened stress on eyewitness identification of the perpetrator or target person and separately on 36 tests of eyewitness recall of details associated with the crime. There was considerable support for the hypothesis that high levels of stress negatively impact both types of eyewitness memory. Meta-analytic Z-scores, whether unweighted or weighted by sample size, ranged from -5.40 to -6.44 (high stress condition-low stress condition). The overall effect sizes were -.31 for both proportion of correct identifications and accuracy of eyewitness recall. Effect sizes were notably larger for target-present than for target-absent lineups, for eyewitness identification studies than for face recognition studies and for eyewitness studies employing a staged crime than for eyewitness studies employing other means to induce stress.

Approximating variance of demographic parameters using the delta method: a reference for avian biologists

Abstract: Avian biologists routinely estimate sampling variance for parameter estimates such as daily nest survival, fecundity, annual survival, and density However, many biologists are not certain of methods to derive sampling variance for parameters when survival rates change temporal scales Similar methods are needed to obtain sampling variance when biologists combine parameter estimates to calculate an indirect demographic parameter, such as population growth rate The delta method is a useful technique for approximating sampling variance when the desired demographic parameter is a function of at least one other demographic parameter However, the delta method is rarely taught in most graduate-level biology or ecology courses, and application of this method may be discouraged by seemingly daunting formulas in reference books Here, I provide five examples of sampling variance approximations for common situations encountered by avian ecologists, with step-by-step explanations of the equations involved

Identification of regional soil quality factors and indicators : I. Central and Southern High Plains

Abstract: Appropriate indicators for assessing soil quality on a regional scale using the National Resource Inventory (NRI) are unknown. Our objectives were to (i) identify soil quality factors present at a regional scale, (ii) determine which factors vary significantly with land use, and (iii) select soil attributes within these factors that can be used as soil quality indicators for regional-scale assessment. Ascalon (fine-loamy, mixed, superactive, mesic Aridic Argiustoll) and Amarillo (fine-loamy, mixed, thermic Aridic Paleustalf) soils were sampled from a statistically representative subset of NRI sample points within the Central and Southern High Plains Major Land Resource Areas (MLRA) and analyzed for 20 soil attributes. Factor analysis was used to identify soil quality factors, and discriminant analysis was used to identify the factors and indicators most sensitive to land use within each MLRA. In the Central High Plains, five soil quality factors were identified, with the organic matter and color factors varying significantly with land use. Discriminant analysis selected total organic C (TOC) and total N as the most sensitive indicators of soil quality at a regional scale. In the Southern High Plains, six factors were identified, with water stable aggregate (WSA) content, TOC, and soil salinity varying significantly with land use. Discriminant analysis selected TOC and WSA content as the most sensitive indicators of soil quality in the Southern High Plains. Total organic C was the only indicator that consistently showed significant differences between land uses in both regions.

An energy efficient and spectrum efficient wireless heterogeneous network framework for 5G systems

Abstract: In this article we explore a system framework of cooperative green heterogeneous networks for 5G wireless communication systems. We first survey the state-of-the-art on spectrum efficiency (SE), energy efficiency (EE), and quality of service (QoS) based mobile association, multi-layer interference management and power control, network wide cooperation and dynamic resource allocation for heterogeneous wireless networks. We also present the system framework of cooperative green heterogeneous networks, which aims at balancing and optimizing SE, EE, and QoS in heterogeneous wireless networks. We discuss the design principles and show some preliminary performance results on the tradeoffs among SE, EE, and QoS. Finally, we identify the technical challenges that remain in the cooperative green heterogeneous network design. The presented wireless system framework is expected to advance the understandings of the critical technical issues toward energy and spectrum efficient 5G wireless communication systems.

Reverberation Mapping Measurements of Black Hole Masses in Six Local Seyfert Galaxies

Abstract: We present the final results from a high sampling rate, multi-month, spectrophotometric reverberation mapping campaign undertaken to obtain either new or improved Hβ reverberation lag measurements for several relatively low-luminosity active galactic nuclei (AGNs). We have reliably measured the time delay between variations in the continuum and Hβ emission line in six local Seyfert 1 galaxies. These measurements are used to calculate the mass of the supermassive black hole at the center of each of these AGNs. We place our results in context to the most current calibration of the broad-line region (BLR) RBLR–L relationship, where our results remove outliers and reduce the scatter at the low-luminosity end of this relationship. We also present velocity-resolved Hβ time-delay measurements for our complete sample, though the clearest velocity-resolved kinematic signatures have already been published.