Showing papers by "University of Nebraska–Lincoln published in 2006"

Designing and Conducting Mixed Methods Research

Abstract: List of Tables List of Figures Preface Purpose of This Book Audience for the Book Book Features Acknowledgments Chapter 1: Understanding Mixed Methods Research Purpose and Organization Clarifying Terms What Is Mixed Methods Research? The Importance of Mixed Methods Research Summary Activities Additional Resources to Examine Chapter 2: Examining Preliminary Considerations Consider Worldview Stances The Basics of Quantitative and Qualitative Research Research Problems Addressed by Mixed Methods Summary Activities Additional Resources to Examine Chapter 3: Locating and Reviewing Mixed Methods Studies Searching for and Reviewing Mixed Methods Studies A Mixed Methods Notation System and Visual Diagrams Four Examples of Mixed Methods Studies Summary Activities Additional Resources to Examine Chapter 4: Choosing a Mixed Methods Design Classifications of Mixed Methods Designs The Four Major Types of Mixed Methods Designs Selecting a Type of Mixed Methods Design Implementing the Design Decisions Writing a Paragraph to Identify a Study's Design Summary Activities Additional Resources to Examine Chapter 5: Introducing a Mixed Methods Study Writing a Mixed Methods Title Stating the Problem in the Introduction The Purpose Statement Research Questions and Hypotheses Summary Activities Additional Resources to Examine Chapter 6: Collecting Data in Mixed Methods Research Procedures in Qualitative and Quantitative Data Collection Data Collection in Mixed Methods Design Summary Activities Additional Resources to Examine Chapter 7: Analyzing Data in Mixed Methods Research Procedures in Quantitative and Qualitative Data Analysis Data Analysis With Mixed Methods Designs Summary Activities Additional Resources to Examine Chapter 8: Writing and Evaluating Mixed Methods Research General Guidelines for Writing Organize the Structure of the Writing So That It Relates to the Designs Evaluating a Mixed Methods Study Within Designs Summary Activities Additional Resources to Examine Chapter 9: Questions Often Raised About Mixed Methods Research Anticipate Mixed Methods Questions What Is Mixed Methods Research? Is Mixed Methods Research Accepted? Is Mixed Methods Research Realistic? Summary Activities Additional Resources to Examine Chapter 10: Future Directions for Mixed Methods Research Needed Developments in Mixed Methods Research Summary Activities Additional Resources to Examine Appendix A. A Triangulation Design Appendix B. An Embedded Design Appendix C. An Explanatory Design Appendix D. An Exploratory Design References Index About the Authors

Using Mixed-Methods Sequential Explanatory Design: From Theory to Practice

Abstract: This article discusses some procedural issues related to the mixed-methods sequential explanatory design, which implies collecting and analyzing quantitative and then qualitative data in two consecutive phases within one study. Such issues include deciding on the priority or weight given to the quantitative and qualitative data collection and analysis in the study, the sequence of the data collection and analysis, and the stage/stages in the research process at which the quantitative and qualitative data are connected and the results are integrated. The article provides a methodological overview of priority, implementation, and mixing in the sequential explanatory design and offers some practical guidance in addressing those issues. It also outlines the steps for graphically representing the procedures in a mixed-methods study. A mixed-methods sequential explanatory study of doctoral students’ persistence in a distance-learning program in educational leadership is used to illustrate the methodological dis...

Recent advances in extraction of nutraceuticals from plants

Abstract: Various novel techniques including ultrasound-assisted extraction, microwave-assisted extraction, supercritical fluid extraction, and accelerated solvent extraction have been developed for the extraction of nutraceuticals from plants in order to shorten the extraction time, decrease the solvent consumption, increase the extraction yield, and enhance the quality of extracts. A critical review was conducted to introduce and compare the conventional Soxhlet extraction and the new alternative methods used for the extraction of nutraceuticals from plants. The practical issues of each extraction method were discussed. Potential uses of those methods for the extraction of nutraceuticals from plant materials was finally summarized.

Biodiversity and ecosystem stability in a decade-long grassland experiment

Abstract: Human-driven ecosystem simplification has highlighted questions about how the number of species in an ecosystem influences its functioning. Although biodiversity is now known to affect ecosystem productivity, its effects on stability are debated. Here we present a long-term experimental field test of the diversity-stability hypothesis. During a decade of data collection in an experiment that directly controlled the number of perennial prairie species, growing-season climate varied considerably, causing year-to-year variation in abundances of plant species and in ecosystem productivity. We found that greater numbers of plant species led to greater temporal stability of ecosystem annual aboveground plant production. In particular, the decadal temporal stability of the ecosystem, whether measured with intervals of two, five or ten years, was significantly greater at higher plant diversity and tended to increase as plots matured. Ecosystem stability was also positively dependent on root mass, which is a measure of perenniating biomass. Temporal stability of the ecosystem increased with diversity, despite a lower temporal stability of individual species, because of both portfolio (statistical averaging) and overyielding effects. However, we found no evidence of a covariance effect. Our results indicate that the reliable, efficient and sustainable supply of some foods (for example, livestock fodder), biofuels and ecosystem services can be enhanced by the use of biodiversity.

Psychological Capital: Developing the Human Competitive Edge

Abstract: Although there are as many answers to the question of how organizations can gain competitive advantage in today's global economy as there are books and experts, one lesson seems very clear: traditional answers and resources are no longer sufficient. This seminal book offers not only an answer regarding how to gain competitive advantage through people, but also a brand new, untapped human resource-psychological capital, or simply PsyCap. Generated from both the positive psychology movement and the authors' pioneering work on positive organizational behavior, PsyCap goes beyond traditionally recognized human and social capital. But PsyCap is not a vague or unscientific concept: to be included in PsyCap, a given positive construct must be based on theory, research, and valid measurement, must be open to development, and must have measurable performance impact. The positive constructs that have been determined to best meet these PsyCap criteria, efficacy (confidence), hope, optimism, and resiliency, are covered in separate chapters in Psychological Capital. After exploring other potential positive constructs such as creativity, wisdom, well being, flow, humor, gratitude, forgiveness, emotional intelligence, spirituality, authenticity, and courage, the authors summarize the research demonstrating the performance impact of PsyCap. They go on to provide the PsyCap Questionnaire (PCQ) as a measurement tool, and the PsyCap Intervention (PCI) as a development aid. Utility analysis indicates that investing in the development of PsyCap as presented in this book can result in a very substantial return. In total, Psychological Capital provides theory, research, measurements, and methods of application for the new resource of psychological capital, a resource that can be developed and sustained for competitive advantage.

Relational Leadership Theory: Exploring the social processes of leadership and organizing

Abstract: While the concept of relationship-oriented behavior has been around since the earliest formal studies of leadership in organizations (Stogdill and Coons, 1957), the term relational leadership is surprisingly new (Brower et al., 2000; Drath, 2001; Murrell, 1997; Uhl-Bien, 2003, 2005). Because of this, its meaning is still uncertain.

Comparative genomics of the lactic acid bacteria

Abstract: Lactic acid-producing bacteria are associated with various plant and animal niches and play a key role in the production of fermented foods and beverages. We report nine genome sequences representing the phylogenetic and functional diversity of these bacteria. The small genomes of lactic acid bacteria encode a broad repertoire of transporters for efficient carbon and nitrogen acquisition from the nutritionally rich environments they inhabit and reflect a limited range of biosynthetic capabilities that indicate both prototrophic and auxotrophic strains. Phylogenetic analyses, comparison of gene content across the group, and reconstruction of ancestral gene sets indicate a combination of extensive gene loss and key gene acquisitions via horizontal gene transfer during the coevolution of lactic acid bacteria with their habitats.

Psychological capital development: toward a micro-intervention

Abstract: After first providing the meaning of psychological capital (PsyCap), we present a micro-intervention to develop it. Drawn from hope, optimism, efficacy, and resiliency development, this PsyCap Intervention (PCI) is shown to have preliminary support for not only increasing participants' PsyCap, but also financial impact and high return on investment. Copyright © 2006 John Wiley & Sons, Ltd.

Founding Family Ownership and Earnings Quality

Abstract: This study investigates the relation between founding family ownership and earnings quality using data from the Standard & Poor's 500 companies. Existing literature has documented that financial reporting is of higher quality when firms have stronger corporate governance mechanisms and when there is greater demand for quality financial reporting. I provide two competing theories of the effect of founding family ownership on the demand and supply of earnings quality: the entrenchment effect and the alignment effect. The empirical results show that, on average, founding family ownership is associated with higher earnings quality. In particular, I find consistent evidence that founding family ownership is associated with lower abnormal accruals, greater earnings informativeness, and less persistence of transitory loss components in earnings. In addition, the results suggest a nonlinear relation between family ownership and earnings quality.

Object recognition in rats and mice: a one-trial non-matching-to-sample learning task to study 'recognition memory'

Abstract: Rats and mice have a tendency to interact more with a novel object than with a familiar object. This tendency has been used by behavioral pharmacologists and neuroscientists to study learning and memory. A popular protocol for such research is the object-recognition task. Animals are first placed in an apparatus and allowed to explore an object. After a prescribed interval, the animal is returned to the apparatus, which now contains the familiar object and a novel object. Object recognition is distinguished by more time spent interacting with the novel object. Although the exact processes that underlie this 'recognition memory' requires further elucidation, this method has been used to study mutant mice, aging deficits, early developmental influences, nootropic manipulations, teratological drug exposure and novelty seeking.

Scale Development and Construct Clarification of Servant Leadership

Abstract: This article presents an integrated construct of servant leadership derived from a review of the literature. Subscale items were developed to measure 11 potential dimensions of servant leadership: calling, listening, empathy, healing, awareness, persuasion, conceptualization, foresight, stewardship, growth, and community building. Data from 80 leaders and 388 raters were used to test the internal consistency, confirm factor structure, and assess convergent, divergent, and predictive validity. Results produced five servant leadership factors—altruistic calling, emotional healing, persuasive mapping, wisdom, and organizational stewardship—with significant relations to transformational leadership, leader-member exchange, extra effort, satisfaction, and organizational effectiveness. Strong factor structures and good performance in all validity criteria indicate that the instrument offers value for future research.

Reactive oxygen species as signals that modulate plant stress responses and programmed cell death.

Abstract: Reactive oxygen species (ROS) are known as toxic metabolic products in plants and other aerobic organisms. An elaborate and highly redundant plant ROS network, composed of antioxidant enzymes, antioxidants and ROS-producing enzymes, is responsible for maintaining ROS levels under tight control. This allows ROS to serve as signaling molecules that coordinate an astonishing range of diverse plant processes. The specificity of the biological response to ROS depends on the chemical identity of ROS, intensity of the signal, sites of production, plant developmental stage, previous stresses encountered and interactions with other signaling molecules such as nitric oxide, lipid messengers and plant hormones. Although many components of the ROS signaling network have recently been identified, the challenge remains to understand how ROS-derived signals are integrated to eventually regulate such biological processes as plant growth, development, stress adaptation and programmed cell death.

A survey of security issues in wireless sensor networks

Abstract: Wireless Sensor Networks (WSNs) are used in many applications in military, ecological, and health-related areas These applications often include the monitoring of sensitive information such as enemy movement on the battlefield or the location of personnel in a building Security is therefore important in WSNs However, WSNs suffer from many constraints, including low computation capability, small memory, limited energy resources, susceptibility to physical capture, and the use of insecure wireless communication channels These constraints make security in WSNs a challenge In this article we present a survey of security issues in WSNs First we outline the constraints, security requirements, and attacks with their corresponding countermeasures in WSNs We then present a holistic view of security issues These issues are classified into five categories: cryptography, key management, secure routing, secure data aggregation, and intrusion detection Along the way we highlight the advantages and disadvantages of various WSN security protocols and further compare and evaluate these protocols based on each of these five categories We also point out the open research issues in each subarea and conclude with possible future research directions on security in WSNs

Nitrogen limitation constrains sustainability of ecosystem response to CO2

Abstract: Enhanced plant biomass accumulation in response to elevated atmospheric CO2 concentration could dampen the future rate of increase in CO2 levels and associated climate warming However, it is unknown whether CO2-induced stimulation of plant growth and biomass accumulation will be sustained or whether limited nitrogen (N) availability constrains greater plant growth in a CO2-enriched world Here we show, after a six-year field study of perennial grassland species grown under ambient and elevated levels of CO2 and N, that low availability of N progressively suppresses the positive response of plant biomass to elevated CO2 Initially, the stimulation of total plant biomass by elevated CO2 was no greater at enriched than at ambient N supply After four to six years, however, elevated CO2 stimulated plant biomass much less under ambient than enriched N supply This response was consistent with the temporally divergent effects of elevated CO2 on soil and plant N dynamics at differing levels of N supply Our results indicate that variability in availability of soil N and deposition of atmospheric N are both likely to influence the response of plant biomass accumulation to elevated atmospheric CO2 Given that limitations to productivity resulting from the insufficient availability of N are widespread in both unmanaged and managed vegetation, soil N supply is probably an important constraint on global terrestrial responses to elevated CO2

Peer exclusion and victimization: Processes that mediate the relation between peer group rejection and children's classroom engagement and achievement?

Abstract: Longitudinal data from a study of kindergarten through 5th graders were used to estimate a structural model in which chronic peer exclusion and chronic peer abuse were hypothesized to mediate the link between children's early peer rejection, later classroom engagement, and achievement. Peer exclusion and abuse were expected to predict changes in 2 forms of school engagement (classroom participation and school avoidance), and changes in both forms of engagement were expected to predict changes in achievement. The model fit the data well and lent support to the premise that distinct forms of peer maltreatment and classroom engagement mediate the link between early peer rejection and changes in children's achievement. Early peer rejection was associated with declining classroom participation and increasing school avoidance, but different forms of chronic peer maltreatment mediated these relations. Whereas chronic peer exclusion principally mediated the link between peer rejection and classroom participation, chronic peer abuse primarily mediated the link between rejection and school avoidance. Children's reduced classroom participation, more than gains in school avoidance, anteceded decrements in children's achievement.

Tunneling Across a Ferroelectric

Abstract: Spontaneously polarized materials through which electrons pass by tunneling may be used in novel electronic devices and may reveal new basic physics at the nanometer scale.

Robot for surgical applications

Abstract: The present invention provides a robot for use inside an open abdominal cavity during minimally-invasive surgery. The robot may include various sensors, imaging devices or manipulators.

Developing the psychological capital of resiliency

Abstract: In these turbulent times, we propose the importance of developing the psychological capital dimension of resiliency. After providing the theoretical background and meaning of psychological capital in general and resiliency in particular, the authors present proactive and reactive human resource development (HRD) strategies for its development. The proactive HRD includes increasing psychological assets, decreasing risk factors, and facilitating processes that allow human resources to enhance their resilience. The reactive HRD largely draws from a broaden-and-build model of positive emotions and self-enhancement, external attribution, and hardiness. The article includes specific guidelines for HRD applications and an agenda for future needed research.

Impacts of genetic bottlenecks on soybean genome diversity.

Abstract: Soybean has undergone several genetic bottlenecks These include domestication in Asia to produce numerous Asian landraces, introduction of relatively few landraces to North America, and then selective breeding over the past 75 years It is presumed that these three human-mediated events have reduced genetic diversity We sequenced 111 fragments from 102 genes in four soybean populations representing the populations before and after genetic bottlenecks We show that soybean has lost many rare sequence variants and has undergone numerous allele frequency changes throughout its history Although soybean genetic diversity has been eroded by human selection after domestication, it is notable that modern cultivars have retained 72% of the sequence diversity present in the Asian landraces but lost 79% of rare alleles (frequency ≤010) found in the Asian landraces Simulations indicated that the diversity lost through the genetic bottlenecks of introduction and plant breeding was mostly due to the small number of Asian introductions and not the artificial selection subsequently imposed by selective breeding The bottleneck with the most impact was domestication; when the low sequence diversity present in the wild species was halved, 81% of the rare alleles were lost, and 60% of the genes exhibited evidence of significant allele frequency changes

Predicted Magnetoelectric Effect in Fe / BaTiO 3 Multilayers: Ferroelectric Control of Magnetism

Abstract: An unexplored physical mechanism which produces a magnetoelectric effect in ferroelectric-ferromagnetic multilayers is studied based on first-principles calculations. Its origin is a change in bonding at the ferroelectric-ferromagnet interface that alters the interface magnetization when the electric polarization reverses. Using Fe/BaTiO3 multilayers as a representative model, we show a sizable difference in magnetic moments of Fe and Ti atoms at the two interfaces dissimilar by the orientation of the local electric dipole moments. The predicted magnetoelectric effect opens a new direction to control magnetic properties of thin-film layered structures by electric fields.

Mother–Child Bookreading in Low‐Income Families: Correlates and Outcomes During the First Three Years of Life

Abstract: About half of 2,581 low-income mothers reported reading daily to their children. At 14 months, the odds of reading daily increased by the child being firstborn or female. At 24 and 36 months, these odds increased by maternal verbal ability or education and by the child being firstborn or of Early Head Start status. White mothers read more than did Hispanic or African American mothers. For English-speaking children, concurrent reading was associated with vocabulary and comprehension at 14 months, and with vocabulary and cognitive development at 24 months. A pattern of daily reading over the 3 data points for English-speaking children and daily reading at any 1 data point for Spanish-speaking children predicted children's language and cognition at 36 months. Path analyses suggest reciprocal and snowballing relations between maternal bookreading and children's vocabulary.

Three-band model for noninvasive estimation of chlorophyll, carotenoids, and anthocyanin contents in higher plant leaves

Abstract: [1] Leaf pigment content and composition provide important information about plant physiological status. Reflectance measurements offer a rapid, nondestructive technique to estimate pigment content. This paper describes a recently developed three-band conceptual model capable of remotely estimating total of chlorophylls, carotenoids and anthocyanins contents in leaves from many tree and crop species. We tuned the spectral regions used in the model in accord with pigment of interest and the optical characteristics of the leaves studied, and showed that the developed technique allowed accurate estimation of total chlorophylls, carotenoids and anthocyanins, explaining more than 91%, 70% and 93% of pigment variation, respectively. This new technique shows a great potential for noninvasive tracking of the physiological status of vegetation and the impact of environmental changes.

Cadaver decomposition in terrestrial ecosystems

Abstract: A dead mammal (i.e. cadaver) is a high quality resource (narrow carbon:nitrogen ratio, high water content) that releases an intense, localised pulse of carbon and nutrients into the soil upon decomposition. Despite the fact that as much as 5,000 kg of cadaver can be introduced to a square kilometre of terrestrial ecosystem each year, cadaver decomposition remains a neglected microsere. Here we review the processes associated with the introduction of cadaver-derived carbon and nutrients into soil from forensic and ecological settings to show that cadaver decomposition can have a greater, albeit localised, effect on belowground ecology than plant and faecal resources. Cadaveric materials are rapidly introduced to belowground floral and faunal communities, which results in the formation of a highly concentrated island of fertility, or cadaver decomposition island (CDI). CDIs are associated with increased soil microbial biomass, microbial activity (C mineralisation) and nematode abundance. Each CDI is an ephemeral natural disturbance that, in addition to releasing energy and nutrients to the wider ecosystem, acts as a hub by receiving these materials in the form of dead insects, exuvia and puparia, faecal matter (from scavengers, grazers and predators) and feathers (from avian scavengers and predators). As such, CDIs contribute to landscape heterogeneity. Furthermore, CDIs are a specialised habitat for a number of flies, beetles and pioneer vegetation, which enhances biodiversity in terrestrial ecosystems.

On the origin and functions of RNA-mediated silencing: from protists to man.

Abstract: Double-stranded RNA has been shown to induce gene silencing in diverse eukaryotes and by a variety of pathways. We have examined the taxonomic distribution and the phylogenetic relationship of key components of the RNA interference (RNAi) machinery in members of five eukaryotic supergroups. On the basis of the parsimony principle, our analyses suggest that a relatively complex RNAi machinery was already present in the last common ancestor of eukaryotes and consisted, at a minimum, of one Argonaute-like polypeptide, one Piwi-like protein, one Dicer, and one RNA-dependent RNA polymerase. As proposed before, the ancestral (but non-essential) role of these components may have been in defense responses against genomic parasites such as transposable elements and viruses. From a mechanistic perspective, the RNAi machinery in the eukaryotic ancestor may have been capable of both small-RNA-guided transcript degradation as well as transcriptional repression, most likely through histone modifications. Both roles appear to be widespread among living eukaryotes and this diversification of function could account for the evolutionary conservation of duplicated Argonaute-Piwi proteins. In contrast, additional RNAi-mediated pathways such as RNA-directed DNA methylation, programmed genome rearrangements, meiotic silencing by unpaired DNA, and miRNA-mediated gene regulation may have evolved independently in specific lineages.

Environmental factors influencing heat stress in feedlot cattle.

Abstract: Data from 3 summer feedlot studies were utilized to determine the environmental factors that influence heat stress in cattle and also to determine wind speed (WSPD; m·s -1 ) and solar radiation (RAD; W·m -2 ) adjustments to the temperature-humidity index (THI). Visual assessments of heat stress, based on panting scores (0 = no panting to 4 = severe panting), were collected from 1400 to 1700. Mean daily WSPD, black globe temperature at 1500, and minimums for nighttime WSPD, nighttime black globe THI, and daily relative humidity were found to have the greatest influence on panting score from 1400 to 1700 (R 2 = 0.61). From hourly values for THI, WSPD, and RAD, panting score was determined to equal -7.563 + (0.121 x THI) - (0.241 x WSPD) + (0.00082 x RAD) (R 2 = 0.49). Using the ratio of WSPD to THI and RAD to THI (-1.992 and 0.0068 for WSPD and RAD, respectively), adjustments to the THI were derived for WSPD and RAD. On the basis of these ratios and the average hourly data for 1400 to 1700, the THI, adjusted for WSPD and RAD, equals [4.51 + THI - (1.992 x WSPD) + (0.0068 x RAD)]. Four separate cattle studies, comparable in size, type of cattle, and number of observations to the 3 original studies, were utilized to evaluate the accuracy of the THI equation adjusted for WSPD and RAD, and the relationship between the adjusted THI and panting score. Mean panting score derived from individual observations of black-hided cattle in these 4 studies were 1.22, 0.94, 1.32, and 2.00 vs. the predicted panting scores of 1.15, 1.17, 1.30, and 1.96, respectively. Correlations between THI and panting score in these studies ranged from r = 0.47 to 0.87. Correlations between the adjusted THI and mean panting score ranged from r = 0.64 to 0.80. These adjustments would be most appropriate to use, within a day, to predict THI during the afternoon hours using hourly data or current conditions. In addition to afternoon conditions, nighttime conditions, including minimum WSPD, minimum black globe THI, and minimum THI, were also found to influence heat stress experienced by cattle. Although knowledge of THI alone is beneficial in determining the potential for heat stress, WSPD and RAD adjustments to the THI more accurately assess animal discomfort.

Chemical composition and response to dilute-acid pretreatment and enzymatic saccharification of alfalfa, reed canarygrass, and switchgrass

Abstract: Alfalfa stems, reed canarygrass, and switchgrass; perennial herbaceous species that have potential as biomass energy crops in temperate regions; were evaluated for their bioconversion potential as energy crops. Each forage species was harvested at two or three maturity stages and analyzed for carbohydrates, lignin, protein, lipid, organic acids, and mineral composition. The biomass samples were also evaluated for sugar yields following pretreatment with dilute sulfuric followed by enzymatic saccharification using a commercial cellulase preparation. Total carbohydrate content of the plants varied from 518 to 655 g kg � 1 dry matter (DM) and cellulose concentration from 209 to 322 g kg � 1 DM. Carbohydrate and lignin contents were lower for samples from early maturity samples compared to samples from late maturity harvests. Several important trends were observed in regards to the efficiency of sugar recovery following treatments with dilute acid and cellulase. First, a significant amount of the available carbohydrates were in the form of soluble sugars and storage carbohydrates (4.3–16.3% wt/wt). Recovery of soluble sugars following dilute acid pretreatment was problematic, especially that of fructose. Fructose was found to be extremely labile to the dilute acid pretreatments. Second, the efficiency at which available glucose was recovered was inversely correlated to maturity and lignin content. However, total glucose yields were higher for the later maturities because of higher cellulose contents compared to the earlier maturity samples. Finally, cell wall polysaccharides, as determined by the widely applied detergent fiber system were found to be inaccurate. The detergent fiber method consistently overestimated cellulose and hemicellulose and underestimated lignin by substantial amounts. Published by Elsevier Ltd.

Herbivore impact on grassland plant diversity depends on habitat productivity and herbivore size.

Abstract: Mammalian herbivores can have pronounced effects on plant diversity but are currently declining in many productive ecosystems through direct extirpation, habitat loss and fragmentation, while being simultaneously introduced as livestock in other, often unproductive, ecosystems that lacked such species during recent evolutionary times. The biodiversity consequences of these changes are still poorly understood. We experimentally separated the effects of primary productivity and herbivores of different body size on plant species richness across a 10-fold productivity gradient using a 7-year field experiment at seven grassland sites in North America and Europe. We show that assemblages including large herbivores increased plant diversity at higher productivity but decreased diversity at low productivity, while small herbivores did not have consistent effects along the productivity gradient. The recognition of these large-scale, cross-site patterns in herbivore effects is important for the development of appropriate biodiversity conservation strategies.

Critical Success Factors for Enterprise Resource Planning Implementation and Upgrade

Abstract: Seven categories of critical success factors were identified from the ERP literature: (1) business plan and vision; (2) change management; (3) communication; (4) ERP team composition, skills and compensation; (5) management support and championship; (6) project management; (7) system analysis, selection and technical implementation. We conducted a case study of two organizations that had implemented and upgraded ERP systems. We adopted Markus and Tanis' four-phase model and compared the importance of these critical success factors across the phases of ERP implementation and upgrade. The importance of these factors across the phases of ERP implementation and upgrade is very similar. ‘Business Plan and Vision’ and ‘Top Management Support and Championship’ are critical during the Chartering phase. ‘ERP Team Composition, Skills and Compensation,’ ‘Project Management’ and ‘System Analysis, Selection and Technical Implementation’ are most important during the Project phase. ‘Change Management’ and ‘Communicatio...

The upgraded DØ detector

Abstract: The D0 experiment enjoyed a very successful data-collection run at the Fermilab Tevatron collider between 1992 and 1996. Since then, the detector has been upgraded to take advantage of improvements to the Tevatron and to enhance its physics capabilities. We describe the new elements of the detector, including the silicon microstrip tracker, central fiber tracker, solenoidal magnet, preshower detectors, forward muon detector, and forward proton detector. The uranium/liquid-argon calorimeters and central muon detector, remaining from Run I, are discussed briefly. We also present the associated electronics, triggering, and data acquisition systems, along with the design and implementation of software specific to D0.