Showing papers by "University of Nebraska–Lincoln published in 2008"

The CMS experiment at the CERN LHC

Abstract: The Compact Muon Solenoid (CMS) detector is described. The detector operates at the Large Hadron Collider (LHC) at CERN. It was conceived to study proton-proton (and lead-lead) collisions at a centre-of-mass energy of 14 TeV (5.5 TeV nucleon-nucleon) and at luminosities up to 10(34)cm(-2)s(-1) (10(27)cm(-2)s(-1)). At the core of the CMS detector sits a high-magnetic-field and large-bore superconducting solenoid surrounding an all-silicon pixel and strip tracker, a lead-tungstate scintillating-crystals electromagnetic calorimeter, and a brass-scintillator sampling hadron calorimeter. The iron yoke of the flux-return is instrumented with four stations of muon detectors covering most of the 4 pi solid angle. Forward sampling calorimeters extend the pseudo-rapidity coverage to high values (vertical bar eta vertical bar <= 5) assuring very good hermeticity. The overall dimensions of the CMS detector are a length of 21.6 m, a diameter of 14.6 m and a total weight of 12500 t.

Internet, Mail, and Mixed-Mode Surveys: The Tailored Design Method

Abstract: The classic survey design reference, updated for the digital ageFor over two decades, Dillman's classic text on survey design has aided both students and professionals in effectively planning and conducting mail, telephone, and, more recently, Internet surveys. The new edition is thoroughly updated and revised, and covers all aspects of survey research. It features expanded coverage of mobile phones, tablets, and the use of do-it-yourself surveys, and Dillman's unique Tailored Design Method is also thoroughly explained. This invaluable resource is crucial for any researcher seeking to increase response rates and obtain high-quality feedback from survey questions. Consistent with current emphasis on the visual and aural, the new edition is complemented by copious examples within the text and accompanying website.This heavily revised Fourth Edition includes:Strategies and tactics for determining the needs of a given survey, how to design it, and how to effectively administer itHow and when to use mail, telephone, and Internet surveys to maximum advantageProven techniques to increase response ratesGuidance on how to obtain high-quality feedback from mail, electronic, and other self-administered surveysDirection on how to construct effective questionnaires, including considerations of layoutThe effects of sponsorship on the response rates of surveysUse of capabilities provided by newly mass-used media: interactivity, presentation of aural and visual stimuli.The Fourth Edition reintroduces the telephoneincluding coordinating land and mobile.Grounded in the best research, the book offers practical how-to guidelines and detailed examples for practitioners and students alike.

CUBIC: a new TCP-friendly high-speed TCP variant

Abstract: CUBIC is a congestion control protocol for TCP (transmission control protocol) and the current default TCP algorithm in Linux. The protocol modifies the linear window growth function of existing TCP standards to be a cubic function in order to improve the scalability of TCP over fast and long distance networks. It also achieves more equitable bandwidth allocations among flows with different RTTs (round trip times) by making the window growth to be independent of RTT -- thus those flows grow their congestion window at the same rate. During steady state, CUBIC increases the window size aggressively when the window is far from the saturation point, and the slowly when it is close to the saturation point. This feature allows CUBIC to be very scalable when the bandwidth and delay product of the network is large, and at the same time, be highly stable and also fair to standard TCP flows. The implementation of CUBIC in Linux has gone through several upgrades. This paper documents its design, implementation, performance and evolution as the default TCP algorithm of Linux.

Short-Term Memory, Working Memory, and Executive Functioning in Preschoolers: Longitudinal Predictors of Mathematical Achievement at Age 7 Years

Abstract: This study examined whether measures of short-term memory, working memory, and executive functioning in preschool children predict later proficiency in academic achievement at 7 years of age (third year of primary school). Children were tested in preschool (M age = 4 years, 6 months) on a battery of cognitive measures, and mathematics and reading outcomes (from standardized, norm-referenced school-based assessments) were taken on entry to primary school, and at the end of the first and third year of primary school. Growth curve analyses examined predictors of math and reading achievement across the duration of the study and revealed that better digit span and executive function skills provided children with an immediate head start in math and reading that they maintained throughout the first three years of primary school. Visual-spatial short-term memory span was found to be a predictor specifically of math ability. Correlational and regression analyses revealed that visual short-term and working memory were found to specifically predict math achievement at each time point, while executive function skills predicted learning in general rather than learning in one specific domain. The implications of the findings are discussed in relation to further understanding the role of cognitive skills in different mathematical tasks, and in relation to the impact of limited cognitive skills in the classroom environment.

The mediating role of psychological capital in the supportive organizational climate—employee performance relationship

Abstract: Summary Although the value of a supportive organizational climate has been recognized over the years, there is a need for better understanding of its relationship with employee outcomes. This study investigates whether the recently emerging core construct of positive psychological capital (consistingofhope,resilience,optimism,andefficacy)playsaroleinmediatingtheeffectsofa supportive organizational climate with employee outcomes. Utilizing three diverse samples, results show that employees’ psychological capital is positively related to their performance, satisfaction, and commitment and a supportive climate is related to employees’ satisfaction and commitment. The study’s major hypothesis that employees’ psychological capital mediates the relationship between supportive climate and their performance was also supported. The implications of these findings conclude the article. Copyright # 2008 John Wiley & Sons, Ltd.

Net energy of cellulosic ethanol from switchgrass

Abstract: Perennial herbaceous plants such as switchgrass (Panicum virgatum L.) are being evaluated as cellulosic bioenergy crops. Two major concerns have been the net energy efficiency and economic feasibility of switchgrass and similar crops. All previous energy analyses have been based on data from research plots (<5 m2) and estimated inputs. We managed switchgrass as a biomass energy crop in field trials of 3–9 ha (1 ha = 10,000 m2) on marginal cropland on 10 farms across a wide precipitation and temperature gradient in the midcontinental U.S. to determine net energy and economic costs based on known farm inputs and harvested yields. In this report, we summarize the agricultural energy input costs, biomass yield, estimated ethanol output, greenhouse gas emissions, and net energy results. Annual biomass yields of established fields averaged 5.2 -11.1 Mg·ha−1 with a resulting average estimated net energy yield (NEY) of 60 GJ·ha−1·y−1. Switchgrass produced 540% more renewable than nonrenewable energy consumed. Switchgrass monocultures managed for high yield produced 93% more biomass yield and an equivalent estimated NEY than previous estimates from human-made prairies that received low agricultural inputs. Estimated average greenhouse gas (GHG) emissions from cellulosic ethanol derived from switchgrass were 94% lower than estimated GHG from gasoline. This is a baseline study that represents the genetic material and agronomic technology available for switchgrass production in 2000 and 2001, when the fields were planted. Improved genetics and agronomics may further enhance energy sustainability and biofuel yield of switchgrass. agriculture bioenergy biomass biomass energy greenhouse gas

Advanced Data Mining Techniques

Abstract: This book covers the fundamental concepts of data mining, to demonstrate the potential of gathering large sets of data, and analyzing these data sets to gain useful business understanding. The book is organized in three parts. Part I introduces concepts. Part II describes and demonstrates basic data mining algorithms. It also contains chapters on a number of different techniques often used in data mining. Part III focusses on business applications of data mining.Methods are presented with simple examples, applications are reviewed, and relativ advantages are evaluated.

Can Positive Employees Help Positive Organizational Change? Impact of Psychological Capital and Emotions on Relevant Attitudes and Behaviors

Abstract: Although much attention has been devoted to understanding employee resistance to change, relatively little research examines the impact that positive employees can have on organizational change. To help fill this need, the authors investigate whether a process of employees’ positivity will have an impact on relevant attitudes and behaviors. Specifically, this study surveyed 132 employees from a broad cross-section of organizations and jobs and found: (a) Their psychological capital (a core factor consisting of hope, efficacy, optimism, and resilience) was related to their positive emotions that in turn were related to their attitudes (engagement and cynicism) and behaviors (organizational citizenship and deviance) relevant to organizational change; (b) mindfulness (i.e., heightened awareness) interacted with psychological capital in predicting positive emotions; and (c) positive emotions generally mediated the relationship between psychological capital and the attitudes and behaviors. The implications these findings have for positive organizational change conclude the article.

Experimental Analysis of a Web-Based Training Intervention to Develop Positive Psychological Capital

Abstract: Psychological capital with components of hope, self-efficacy, optimism, and resiliency has recently emerged as a core construct in taking positive psychology to the workplace. A distinguishing feat...

COI1 is a critical component of a receptor for jasmonate and the bacterial virulence factor coronatine

Abstract: Jasmonate (JA) is a lipid-derived hormone that regulates diverse aspects of plant immunity and development. An amino acid-conjugated form of JA, jasmonoyl–isoleucine (JA–Ile), stimulates binding of the F-box protein coronatine-insensitive 1 (COI1) to, and subsequent ubiquitin-dependent degradation of, jasmonate ZIM domain (JAZ) proteins that repress transcription of JA-responsive genes. The virulence factor coronatine (COR), which is produced by plant pathogenic strains of Pseudomonas syringae, suppresses host defense responses by activating JA signaling in a COI1-dependent manner. Although previous data indicate that COR acts as a molecular mimic of JA–Ile, the mechanism by which JA–Ile and COR are perceived by plant cells remains unknown. Here, we show that interaction of tomato COI1 with divergent members of the JAZ family is highly specific for JA–Ile and structurally related JA conjugates and that COR is ≈1,000-fold more active than JA–Ile in promoting this interaction in vitro. JA–Ile competes for binding of COR to COI1–JAZ complexes, demonstrating that COR and JA–Ile are recognized by the same receptor. Binding of COR to the COI1–JAZ complex requires COI1 and is severely impaired by a point mutation in the putative ligand-binding pocket of COI1. Finally, we show that the C-terminal region of JAZ3 containing the highly conserved Jas motif is necessary and sufficient for hormone-induced COI1–JAZ interaction. These findings demonstrate that COI1 is a critical component of the JA receptor and that COR exerts its virulence effects by functioning as a potent agonist of this receptor system.

Using confirmatory factor analysis to understand executive control in preschool children: I. Latent structure.

Abstract: Although many tasks have been developed recently to study executive control in the preschool years, the constructs that underlie performance on these tasks are poorly understood. In particular, it is unclear whether executive control is composed of multiple, separable cognitive abilities (e.g., inhibition and working memory) or whether it is unitary in nature. A sample of 243 normally developing children between 2.3 and 6 years of age completed a battery of age-appropriate executive control tasks. Confirmatory factor analysis was used to compare multiple models of executive control empirically. A single-factor, general model was sufficient to account for the data. Furthermore, the fit of the unitary model was invariant across subgroups of children divided by socioeconomic status or sex. Girls displayed a higher level of latent executive control than boys, and children of higher and lower socioeconomic status did not differ in level. In typically developing preschool children, tasks conceptualized as indexes of working memory and inhibitory control in fact measured a single cognitive ability, despite surface differences between task characteristics.

The Joint Effect of Investor Protection and Big 4 Audits on Earnings Quality around the World

Abstract: The association of a country's investor protection regime with the quality of reported earnings is examined for a large sample of firms from 42 countries. Three attributes of earnings are evaluated: the magnitude of abnormal accruals, the likelihood of reporting losses, and earnings conservatism (timely loss recognition). We find that earnings quality increases for firms with Big 4 auditors when a country's investor protection regime gives stronger protection to investors; specifically, abnormal accruals are smaller, there is a greater likelihood of reporting losses, and earnings conservatism is greater. In contrast, earnings of firms with non-Big 4 auditors are largely unaffected by different investor protection regimes. The study adds to a growing body of research showing that accounting practices are influenced by a country's institutions. However, our results differ from prior studies by demonstrating that country-level effects are mediated by audit enforcement, and in particular the incentives of Big 4 auditors to perform higher quality audits in countries with stricter investor protection regimes.

Modular and cooperative medical devices and related systems and methods

Abstract: The various embodiments disclosed herein relate to modular medical devices, including various devices with detachable modular components and various devices with pivotally attached modular components. Additional embodiments relate to procedures in which various of the devices are used cooperatively. Certain embodiments of the medical devices are robotic in vivo devices.

Observation of the suppression of the flux of cosmic rays above 4x10(19) eV

Abstract: The energy spectrum of cosmic rays above 2.5 x 10;{18} eV, derived from 20,000 events recorded at the Pierre Auger Observatory, is described. The spectral index gamma of the particle flux, J proportional, variantE;{-gamma}, at energies between 4 x 10;{18} eV and 4 x 10;{19} eV is 2.69+/-0.02(stat)+/-0.06(syst), steepening to 4.2+/-0.4(stat)+/-0.06(syst) at higher energies. The hypothesis of a single power law is rejected with a significance greater than 6 standard deviations. The data are consistent with the prediction by Greisen and by Zatsepin and Kuz'min.

Biodistribution, clearance, and biocompatibility of iron oxide magnetic nanoparticles in rats.

Abstract: It is essential to determine the biodistribution, clearance, and biocompatibility of magnetic nanoparticles (MNPs) for in vivo biomedical applications to ensure their safe clinical use. We have studied these aspects with our novel iron oxide MNP formulation, which can be used as a magnetic resonance imaging (MRI) agent and a drug carrier system. Changes in serum and tissue iron levels were analyzed over 3 weeks after intravenous administration of MNPs to rats. Serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AKP) levels, and total iron-binding capacity (TIBC) were also measured with time to assess the effect of MNPs on liver function. Selected tissues were also analyzed for oxidative stress and studied histologically to determine biocompatibility of MNPs. Serum iron levels gradually increased for up to 1 week but levels slowly declined thereafter. Biodistribution of iron in various body tissues changed with time but greater fraction of the injected iron localized in the liver and spleen than in the brain, heart, kidney, and lung. Magnetization measurements of the liver and spleen samples showed a steady decrease over 3 weeks, suggesting particle degradation. Serum showed a transient increase in ALT, AST, AKP levels, and TIBC over a period of 6-24 h following MNP injection. The increase in oxidative stress was tissue dependent, reaching a peak at approximately 3 days and then slowly declining thereafter. Histological analyses of liver, spleen, and kidney samples collected at 1 and 7 days showed no apparent abnormal changes. In conclusion, our MNPs did not cause long-term changes in the liver enzyme levels or induce oxidative stress and thus can be safely used for drug delivery and imaging applications.

Surface magnetoelectric effect in ferromagnetic metal films.

Abstract: A surface magnetoelectric effect is revealed by density-functional calculations that are applied to ferromagnetic Fe(001), Ni(001), and Co(0001) films in the presence of an external electric field. The effect originates from spin-dependent screening of the electric field which leads to notable changes in the surface magnetization and the surface magnetocrystalline anisotropy. These results are of considerable interest in the area of electrically controlled magnetism and magnetoelectric phenomena.

Ecological Role of Lactobacilli in the Gastrointestinal Tract: Implications for Fundamental and Biomedical Research

Abstract: Bacteria belonging to the genus Lactobacillus are members of the lactic acid bacteria (LAB), a broadly defined group characterized by the formation of lactic acid as the sole or main end product of carbohydrate metabolism. They can be found in plants or material of plant origin, silage, fermented food (yogurt, cheese, olives, pickles, salami, etc.), as well as in the oral cavities, gastrointestinal tracts (GIT), and vaginas of humans and animals (31). In particular, the Lactobacillus species found in the GIT have received tremendous attention due to their health-promoting properties. They are commonly used as probiotics, which are defined by the FAO/WHO as live microorganisms that when administered in adequate amounts confer a health benefit on the host. The economic success and exciting prospects of probiotic products have accelerated research on intestinal lactobacilli. Genomics of Lactobacillus species is booming, and the genomes of five strains that belong to species commonly found in human fecal samples have recently been sequenced (50). Several comparative and functional genomic investigations have been conducted to gain information about the functionality of lactobacilli in the GIT (69). Unfortunately, a major misconception regarding the ecological role of lactobacilli in the intestinal tract has been embraced by many scientists working in the field. Specifically, there has been a general and persistent assumption that a large number of Lactobacillus species form stable and numerically significant populations in the human intestinal tract, especially in the small intestine, where they are presumed to form epithelial associations (101). Considering how widespread and accepted this perception is, there is surprisingly little experimental evidence that supports it. Ecological observations for the prevalence and dynamics of fecal Lactobacillus populations and the findings obtained with comparative genomics do indicate now that the ecological role of most types of intestinal lactobacilli, and their relationship with the human host, should be reconsidered. In this review, evidence is summarized that suggests that only a small number of Lactobacillus species are true inhabitants of the mammalian intestinal tract and that most lactobacilli present are allochthonous members derived from fermented food, the oral cavity, or more proximal parts of the GIT. It is further explained why this knowledge provides information valuable for selecting strains for fundamental research of the ecological role of lactobacilli in the GIT, for their use as probiotics in foods and supplements, and for pharmaceutical applications.

Cobalt oxide surface chemistry: The interaction of CoO(1 0 0), Co3O4(1 1 0) and Co3O4(1 1 1) with oxygen and water

Abstract: Cobalt oxides comprise two readily accessible cation oxidation states: Co 2+ and Co 3+ , which are thermodynamically competitive under common ambient conditions, and redox mechanisms connecting the two states are largely responsible for their success in partial oxidation catalysis. In our studies, CoO(1 0 0), Co 3 O 4 (1 1 0), and Co 3 O 4 (1 1 1) single crystal substrates have been investigated with X-ray photoelectron spectroscopy (XPS), high-resolution electron energy loss spectroscopy (HREELS), and low energy electron diffraction (LEED) for their surface reactivity toward O 2 and H 2 O and for their stability under reducing UHV conditions. There is facile inter-conversion between CoO and Co 3 O 4 stoichiometry at the oxide surface which, despite the compositional variability, remains well ordered in long-range structure. Surface impurities, however, can pin the surface at either CoO or Co 3 O 4 compositional extremes. Contrary to reports of a pressure gap that creates difficulty in oxide hydroxylation under UHV, it is pos sible to hydroxylate both cobalt monoxide and spinel oxide substrates with H 2 O, provided sufficient activation is available to dis sociate the water molecule.

Environmental Context, Managerial Cognition, and Strategic Action: An Integrated View

Abstract: This study addresses an apparent disconnect between two views of strategic action: the ‘economic view,’ which contends that industry structure is the primary influence on strategic action, and the ‘cognitive view,’ which suggests that managerial cognition drives strategic action. We argue that this disconnect has created artificial boundaries between the two perspectives and has limited our ability to develop holistic explanations of strategic action. In response, we develop an integrated model that answers two questions: 1) Does industry context affect managerial cognition? 2) Does managerial cognition mediate the relationship between industry context and strategic responses to environmental changes? To examine these questions, we study the relationship between industry velocity, the structure of top management's cognitive representation of the environment, and the speed of response to environmental events. We find that industry velocity influences the structure of cognitive representations, which in turn influence the speed of response to environmental events. These results support our contention that both industry and cognition variables are critical in developing explanations of strategic actions. These results have implications for our understanding of the development of top managers' beliefs, the relationship between beliefs and action, and the nature of the complex relationship between industry context, managerial cognition, and strategic action. Copyright © 2008 John Wiley & Sons, Ltd.

Application of Spectral Remote Sensing for Agronomic Decisions

Abstract: Remote sensing has provided valuable insights into agronomic management over the past 40 yr. The contributions of individuals to remote sensing methods have lead to understanding of how leaf reflectance and leaf emittance changes in response to leaf thickness, species, canopy shape, leaf age, nutrient status, and water status. Leaf chlorophyll and the preferential absorption at different wavelengths provides the basis for utilizing reflectance with either broad-band radiometers typical of current satellite platforms or hyperspectral sensors that measure reflectance at narrow wavebands. Understanding of leaf reflectance has lead to various vegetative indices for crop canopies to quantify various agronomic parameters, e.g., leaf area, crop cover, biomass, crop type, nutrient status, and yield. Emittance from crop canopies is a measure of leaf temperature and infrared thermometers have fostered crop stress indices currently used to quantify water requirements. These tools are being developed as we learn how to use the information provided in reflectance and emittance measurements with a range of sensors. Remote sensing continues to evolve as a valuable agronomic tool that provides information to scientists, consultants, and producers about the status of their crops. This area is still relatively new compared with other agronomic fields; however, the information content is providing valuable insights into improved management decisions. This article details the current status of our understanding of how reflectance and emittance have been used to quantitatively assess agronomic parameters and some of the challenges facing future generations of scientists seeking to further advance remote sensing for agronomic applications.

An efficient chromatin immunoprecipitation (ChIP) protocol for studying histone modifications in Arabidopsis plants

Abstract: Chromatin immunoprecipitation (ChIP) is a powerful tool for the characterization of covalent histone modifications and DNA-histone interactions in vivo. The procedure includes DNA-histone cross-linking in chromatin, shearing DNA into smaller fragments, immunoprecipitation with antibodies against the histone modifications of interest, followed by PCR identification of associated DNA sequences. In this protocol, we describe a simplified and optimized version of ChIP assay by reducing the number of experimental steps and isolation solutions and shortening preparation times. We include a nuclear isolation step before chromatin shearing, which provides a good yield of high-quality DNA resulting in at least 15 mug of DNA from each immunoprecipitated sample (from 0.2 to 0.4 g of starting tissue material) sufficient to test > or =25 genes of interest. This simpler and cost-efficient protocol has been applied for histone-modification studies of various Arabidopsis thaliana tissues and is easy to adapt for other systems as well.

Cultural considerations in adolescent suicide prevention and psychosocial treatment

Abstract: Ethnic groups differ in rates of suicidal behaviors among youths, the context within which suicidal behavior occurs (e.g., different precipitants, vulnerability and protective factors, and reactions to suicidal behaviors), and patterns of help-seeking. In this article, the authors discuss the cultural context of suicidal behavior among African American, American Indian and Alaska Native, Asian American and Pacific Islander, and Latino adolescents, and the implications of these contexts for suicide prevention and treatment. Several cross-cutting issues are discussed, including acculturative stress and protective factors within cultures; the roles of religion and spirituality and the family in culturally sensitive interventions; different manifestations and interpretations of distress in different cultures; and the impact of stigma and cultural distrust on help-seeking. The needs for culturally sensitive and community-based interventions are discussed, along with future opportunities for research in intervention development and evaluation.

Political Attitudes Vary with Physiological Traits

Abstract: Although political views have been thought to arise largely from individuals' experiences, recent research suggests that they may have a biological basis. We present evidence that variations in political attitudes correlate with physiological traits. In a group of 46 adult participants with strong political beliefs, individuals with measurably lower physical sensitivities to sudden noises and threatening visual images were more likely to support foreign aid, liberal immigration policies, pacifism, and gun control, whereas individuals displaying measurably higher physiological reactions to those same stimuli were more likely to favor defense spending, capital punishment, patriotism, and the Iraq War. Thus, the degree to which individuals are physiologically responsive to threat appears to indicate the degree to which they advocate policies that protect the existing social structure from both external (outgroup) and internal (norm-violator) threats.

Contemporary issues in thermal gasification of biomass and its application to electricity and fuel production.

Abstract: Gasification technology has been investigated to effectively and economically convert low-value and highly distributed solid biomass to a uniform gaseous mixture mainly including hydrogen (H 2 ), carbon monoxide (CO), methane (CH 4 ) and carbon dioxide (CO 2 ). This gaseous mixture can be further used as an industrial feedstock for heat and power generation, H 2 production and synthesis of liquid fuels. Significant advances have been made in the technology of biomass gasification and syngas utilization. This review was conducted to introduce the recent advances in biomass gasification and syngas utilization. The critical technical issues and perspectives of biomass gasification were discussed.

BOARD-INVITED REVIEW: Use of distillers by-products in the beef cattle feeding industry.

Abstract: The ethanol industry is expanding rap- idly. This expansion in production of renewable energy also increases production of by-products. These by- products, primarily distillers grains plus solubles (DGS), are utilized very efficiently by ruminants. When the starch in corn is fermented to produce ethanol, the remaining nutrients (protein, fat, fiber) are concen- trated about 3-fold. Whereas DGS is an excellent pro- tein source for ruminants, the large supply and the price relative to corn make DGS an attractive energy source as well. This is especially important with re- duced availability and higher price of corn because of demand by the ethanol industry. A meta-analysis of 9 experiments, where various levels of wet DGS were fed to feedlot cattle, shows that wet DGS produced higher ADG and G:F compared with cattle fed corn-based diets