Showing papers by "University of Nebraska–Lincoln published in 2009"
01 Jan 2009
TL;DR: A Framework for Design Three Elements of Inquiry Alternative Knowledge Claims Strategies of Inquiry Research Methods Three Approaches to Research Criteria for Selecting an Approach Personal Experiences Audience Summary Writing Exercises Additional Readings.
4,309 citations
TL;DR: This review examines recent theoretical and empirical developments in the leadership literature, beginning with topics that are currently receiving attention in terms of research, theory, and practice and concluding with work that has been done on substitutes for leadership, servant leadership, spirituality and leadership, cross-cultural leadership, and e-leadership.
Abstract: This review examines recent theoretical and empirical developments in the leadership literature, beginning with topics that are currently receiving attention in terms of research, theory, and practice. We begin by examining authentic leadership and its development, followed by work that takes a cognitive science approach. We then examine new-genre leadership theories, complexity leadership, and leadership that is shared, collective, or distributed. We examine the role of relationships through our review of leader member exchange and the emerging work on followership. Finally, we examine work that has been done on substitutes for leadership, servant leadership, spirituality and leadership, cross-cultural leadership, and e-leadership. This structure has the benefit of creating a future focus as well as providing an interesting way to examine the development of the field. Each section ends with an identification of issues to be addressed in the future, in addition to the overall integration of the literature we provide at the end of the article.
2,402 citations
TL;DR: Forensic Entomology: An Introduction is not a reference or a manual; it is an introductory undergraduate text that could even serve as a supplemental text in some graduate courses.
Abstract: Dorothy E. Gennard. Forensic Entomology: An IntroductionJohn Wiley and Sons, Chichester, United Kingdom, 2007224 pp., $55.00 (soft), ISBN: 978-0-470-01479-0
As forensic entomologists, we constantly hear claims that student interest in forensic science is a passing fad. However, a close inspection of past and future needs soon shows that the demand for more and better qualified forensic scientists has been strong and continues to grow. In much the same way, readers sometimes make a cursory scan of a book and dismiss it as light weight or superficial. We made that mistake with Forensic Entomology: An Introduction —we didn’t expect the book to amount to much, but the more we read, the more we found to value. As we have learned yet again, whereas you can judge a blow fly by its puparium, you can’t judge a booklouse by its exoskeleton.
Forensic Entomology: An Introduction is not a reference or a manual; it is an introductory undergraduate text. Actually, it could even serve as a supplemental text in some graduate courses …
1,633 citations
Book•
01 Jan 2009TL;DR: The Rasch Models for Ordered Polytomous Data and the Generalized Partial Credit Model: Conceptual Development of the Multiple-Choice Model, and Issues to Consider in Selecting among the 1PL, 2PL, and 3PL Models.
Abstract: Symbols and Acronyms Part 1 Introduction to Measurement Measurement Some Measurement Issues Item Response Theory Classical Test Theory Latent Class Analysis Summary Part 2 The One-Parameter Model Conceptual Development of the Rasch Model The One-Parameter Model The One-Parameter Logistic Model and the Rasch Model Assumptions underlying the Model An Empirical Data Set: The Mathematics Data Set Conceptually Estimating an Individual's Location Some Pragmatic Characteristics of Maximum Likelihood Estimates The Standard Error of Estimate and Information An Instrument's Estimation Capacity Summary Part 3 Joint Maximum Likelihood Parameter Estimation Joint Maximum Likelihood Estimation Indeterminacy of Parameter Estimates How Large a Calibration Sample? Example: Application of the Rasch Model to the Mathematics Data, JMLE Summary Part 4 Marginal Maximum Likelihood Parameter Estimation Marginal Maximum Likelihood Estimation Estimating an Individual's Location: Expected A Posteriori Example: Application of the Rasch Model to the Mathematics Data, MMLE Metric Transformation and the Total Characteristic Function Summary Part 5 The Two-Parameter Model Conceptual Development of the Two-Parameter Model Information for the Two-Parameter Model Conceptual Parameter Estimation for the 2PL Model How Large a Calibration Sample? Metric Transformation, 2PL Model Example: Application of the 2PL Model to the Mathematics Data, MMLE Information and Relative Efficiency Summary Part 6 The Three-Parameter Model Conceptual Development of the Three-Parameter Model Additional Comments about the Pseudo-Guessing Parameter Conceptual Estimation for the 3PL Model How Large a Calibration Sample? Assessing Conditional Independence Example: Application of the 3PL Model to the Mathematics Data, MMLE Assessing Person Fit: Appropriateness Measurement Information for the Three-Parameter Model Metric Transformation, 3PL Model Handling Missing Responses Issues to Consider in Selecting among the 1PL, 2PL, and 3PL Models Summary Part 7 Rasch Models for Ordered Polytomous Data Conceptual Development of the Partial Credit Model Conceptual Parameter Estimation of the PC Model Example: Application of the PC Model to a Reasoning Ability Instrument, MMLE The Rating Scale Model Conceptual Estimation of the RS Model Example: Application of the RS Model to an Attitudes toward Condom Scale, JMLE How Large a Calibration Sample? Information for the PC and RS Models Metric Transformation, PC and RS Models Summary Part 8 Non-Rasch Models for Ordered Polytomous Data The Generalized Partial Credit Model Example: Application of the GPC Model to a Reasoning Ability Instrument, MMLE Conceptual Development of the Graded Response Model How Large a Calibration Sample? Example: Application of the GR Model to an Attitudes toward Condom Scale, MMLE Information for Graded Data Metric Transformation, GPC and GR Models Summary Part 9 Models for Nominal Polytomous Data Conceptual Development of the Nominal Response Model How Large a Calibration Sample? Example: Application of the NR Model to a Science Test, MMLE Example: Mixed Model Calibration of the Science Test-NR and PC Models, MMLE Example: NR and PC Mixed Model Calibration of the Science Test, Collapsed Options, MMLE Information for the NR Model Metric Transformation, NR Model Conceptual Development of the Multiple-Choice Model Example: Application of the MC Model to a Science Test, MMLE Example: Application of the BS Model to a Science Test, MMLE Summary Part 10 Models for Multidimensional Data Conceptual Development of a Multidimensional IRT Model Multidimensional Item Location and Discrimination Item Vectors and Vector Graphs The Multidimensional Three-Parameter Logistic Model Assumptions of the MIRT Model Estimation of the M2PL Model Information for the M2PL Model Indeterminacy in MIRT Metric Transformation, M2PL Model Example: Application of the M2PL Model, Normal-Ogive Harmonic Analysis Robust Method Obtaining Person Location Estimates Summary Part 11 Linking and Equating Equating Defined Equating: Data Collection Phase Equating: Transformation Phase Example: Application of the Total Characteristic Function Equating Summary Part 12 Differential Item Functioning Differential Item Functioning and Item Bias Mantel-Haenszel Chi-Square The TSW Likelihood Ratio Test Logistic Regression Example: DIF Analysis Summary Appendix A: Maximum Likelihood Estimation of Person Locations Estimating an Individual's Location: Empirical Maximum Likelihood Estimation Estimating an Individual's Location: Newton's Method for MLE Revisiting Zero Variance Binary Response Patterns Appendix B: Maximum Likelihood Estimation of Item Locations Appendix C: The Normal Ogive Models Conceptual Development of the Normal Ogive Model The Relationship between IRT Statistics and Traditional Item Analysis Indices Relationship of the Two-Parameter Normal Ogive and Logistic Models Extending the Two-Parameter Normal Ogive Model to a Multidimensional Space Appendix D: Computerized Adaptive Testing A Brief History Fixed-Branching Techniques Variable-Branching Techniques Advantages of Variable-Branching over Fixed-Branching Methods IRT-Based Variable-Branching Adaptive Testing Algorithm Appendix E Miscellanea Linear Logistic Test Model (LLTM) Using Principal Axis for Estimating Item Discrimination Infinite Item Discrimination Parameter Estimates Example: NOHARM Unidimensional Calibration An Approximate Chi-Square Statistic for NOHARM Mixture Models Relative Efficiency, Monotonicity, and Information FORTRAN Formats Example: Mixed Model Calibration of the Science Test-NR and 2PL Models, MMLE Example: Mixed Model Calibration of the Science Test-NR and GR Models, MMLE Odds, Odds Ratios, and Logits The Person Response Function Linking: A Temperature Analogy Example Should DIF Analyses Be Based on Latent Classes? The Separation and Reliability Indices Dependency in Traditional Item Statistics and Observed Scores
1,296 citations
University of Alberta1, ExxonMobil2, University of Houston3, Louisiana State University4, Queen's University5, University of Pretoria6, University of Nebraska–Lincoln7, University of Texas at Austin8, Dalhousie University9, New Mexico State University10, University of Texas at Arlington11, University of South Carolina12, University of Toronto13, Colorado School of Mines14, Chevron Corporation15, University of Saskatchewan16, University of Fribourg17, Durham University18, Royal Dutch Shell19
TL;DR: In this paper, a model-independent framework of genetic units and bounding surfaces for sequence stratigraphy has been proposed, based on the interplay of accommodation and sedimentation (i.e., forced regressive, lowstand and highstand normal regressive), which are bounded by sequence stratigraphic surfaces.
1,255 citations
TL;DR: In this paper, the authors identified several priorities for future research to reduce the yield gap between average and potential yields in irrigated agriculture, and proposed tools to address the uncertainty in growing season weather.
Abstract: Future trajectories of food prices, food security, and cropland expansion are closely linked to future average crop yields in the major agricultural regions of the world. Because the maximum possible yields achieved in farmers’ fields might level off or even decline in many regions over the next few decades, reducing the gap between average and potential yields is critical. In most major irrigated wheat, rice, and maize systems, yields appear to be at or near 80% of yield potential, with no evidence for yields having exceeded this threshold to date. A fundamental constraint in these systems appears to be uncertainty in growing season weather; thus tools to address this uncertainty would likely reduce gaps. Otherwise, short-term prospects for yield gains in irrigated agriculture appear grim without increased yield potential. Average yields in rainfed systems are commonly 50% or less of yield potential, suggesting ample room for improvement, though estimation of yield gaps for rainfed regions is subject to more errors than for irrigated regions. Several priorities for future research are identified.
1,196 citations
TL;DR: In this article, a large sample of working adults across a variety of industries suggest that psychological capital (the positive resources of efficacy, hope, optimism, and resilience) may be key to better understanding the variation in perceived symptoms of stress, as well as intentions to quit and job search behaviors.
Abstract: Workplace stress is a growing concern for human resource managers. Although considerable scholarly and practical attention has been devoted to stress management over the years, the time has come for new perspectives and research. Drawing from the emerging field of positive organizational behavior, this study offers research findings with implications for combating occupational stress. Specifically, data from a large sample of working adults across a variety of industries suggest that psychological capital (the positive resources of efficacy, hope, optimism, and resilience) may be key to better understanding the variation in perceived symptoms of stress, as well as intentions to quit and job search behaviors. The article concludes with practical strategies aimed at leveraging and developing employees' psychological capital to help them better cope with workplace stress. © 2009 Wiley Periodicals, Inc.
916 citations
TL;DR: A consensus group of experts comprised of experts in pediatric and adult endocrinology, diabetes education, transplantation, metabolism, bariatric/metabolic surgery, and (for another perspective) hematology-oncology met in June 2009 to discuss issues.
Abstract: The mission of the American Diabetes Association is “to prevent and cure diabetes and to improve the lives of all people affected by diabetes.” Increasingly, scientific and medical articles (1) and commentaries (2) about diabetes interventions use the terms “remission” and “cure” as possible outcomes. Several approved or experimental treatments for type 1 and type 2 diabetes (e.g., pancreas or islet transplants, immunomodulation, bariatric/metabolic surgery) are of curative intent or have been portrayed in the media as a possible cure. However, defining remission or cure of diabetes is not as straightforward as it may seem. Unlike “dichotomous” diseases such as many malignancies, diabetes is defined by hyperglycemia, which exists on a continuum and may be impacted over a short time frame by everyday treatment or events (medications, diet, activity, intercurrent illness). The distinction between successful treatment and cure is blurred in the case of diabetes. Presumably improved or normalized glycemia must be part of the definition of remission or cure. Glycemic measures below diagnostic cut points for diabetes can occur with ongoing medications (e.g., antihyperglycemic drugs, immunosuppressive medications after a transplant), major efforts at lifestyle change, a history of bariatric/metabolic surgery, or ongoing procedures (such as repeated replacements of endoluminal devices). Do we use the terms remission or cure for all patients with normal glycemic measures, regardless of how this is achieved?
A consensus group comprised of experts in pediatric and adult endocrinology, diabetes education, transplantation, metabolism, bariatric/metabolic surgery, and (for another perspective) hematology-oncology met in June 2009 to discuss these issues. The group considered a wide variety of questions, including whether it is ever accurate to say that a chronic illness is cured; what the definitions of management, remission, or cure might be; whether goals of managing comorbid conditions revert to those of patients without diabetes if someone is …
880 citations
ExxonMobil1, University of Houston2, University of Pretoria3, University of Nebraska–Lincoln4, University of Texas at Austin5, New Mexico State University6, University of Texas at Arlington7, University of South Carolina8, University of Toronto9, University of the Balearic Islands10, Chevron Corporation11, University of Saskatchewan12, University of Fribourg13, Royal Dutch Shell14
TL;DR: Catuneanu et al. as discussed by the authors used a neutral approach that focused on model-independent, fundamental concepts, because these are the ones common to various approaches and this search for common ground is what they meant by "standardization", not the imposition of a strict, inflexible set of rules for the placement of sequence-stratigraphicsurfaces.
872 citations
TL;DR: An energy decomposition analysis method is implemented for the analysis of both covalent bonds and intermolecular interactions on the basis of single-determinant Hartree-Fock wavefunctions and their density functional theory analogs, which shows that this algorithm is simple and robust.
Abstract: An energy decomposition analysis method is implemented for the analysis of both covalent bonds and intermolecular interactions on the basis of single-determinant Hartree–Fock (HF) (restricted closed shell HF, restricted open shell HF, and unrestricted open shell HF) wavefunctions and their density functional theory analogs. For HF methods, the total interaction energy from a supermolecule calculation is decomposed into electrostatic, exchange, repulsion, and polarization terms. Dispersion energy is obtained from second-order Moller–Plesset perturbation theory and coupled-cluster methods such as CCSD and CCSD(T). Similar to the HF methods, Kohn–Sham density functional interaction energy is decomposed into electrostatic, exchange, repulsion, polarization, and dispersion terms. Tests on various systems show that this algorithm is simple and robust. Insights are provided by the energy decomposition analysis into H2, methane C–H, and ethane C–C covalent bond formation, CH3CH3 internal rotation barrier, water, ...
826 citations
TL;DR: In this paper, the authors investigated the components of an expanded view of psychological ownership, including selfefficacy, accountability, sense of belongingness and self-identity, and territoriality as a unique and more "prevention-focused" form of ownership.
Abstract: Summary Viewing psychological ownership as a positive resource for impacting human performance in organizations, the present study investigated the components of an expanded view of psychological ownership. Confirmatory factor analyses on a proposed measure of psychological ownership provided support for a positively-oriented, ‘‘promotion-focused’’ aspect of psychological ownership comprised of four dimensions: self-efficacy, accountability, sense of belongingness and self-identity. In addition, territoriality was examined as a unique and more ‘‘prevention-focused’’ form of ownership. Practical implications and suggestions for future research on psychological ownership and positive organizational behavior conclude the article. Copyright # 2009 John Wiley & Sons, Ltd.
TL;DR: New methods to identify and quantify individual pigments in the presence of overlapping absorption features would provide a major advance in understanding their biological functions, quantifying net carbon exchange, and identifying plant stresses.
GNS Science1, Victoria University of Wellington2, Northern Illinois University3, University of Nebraska–Lincoln4, University of Otago5, University of Siena6, Ohio State University7, National Institute of Geophysics and Volcanology8, University of Massachusetts Amherst9, Harvard University10, Pennsylvania State University11, New Mexico Institute of Mining and Technology12, Appalachian State University13, Johns Hopkins University14, University of Milano-Bicocca15, Colorado School of Mines16, Denver Federal Center17, University of Wisconsin–Oshkosh18, University of Parma19, Iowa State University20, Stanford University21, University of Alberta22, Louisiana State University23, Albion College24, Lamont–Doherty Earth Observatory25
TL;DR: A marine glacial record from the upper 600 m of the AND-1B sediment core recovered from beneath the northwest part of the Ross ice shelf is presented and well-dated, ∼40-kyr cyclic variations in ice-sheet extent linked to cycles in insolation influenced by changes in the Earth’s axial tilt (obliquity) during the Pliocene are demonstrated.
Abstract: Thirty years after oxygen isotope records from microfossils deposited in ocean sediments confirmed the hypothesis that variations in the Earth's orbital geometry control the ice ages, fundamental questions remain over the response of the Antarctic ice sheets to orbital cycles. Furthermore, an understanding of the behaviour of the marine-based West Antarctic ice sheet (WAIS) during the 'warmer-than-present' early-Pliocene epoch ( approximately 5-3 Myr ago) is needed to better constrain the possible range of ice-sheet behaviour in the context of future global warming. Here we present a marine glacial record from the upper 600 m of the AND-1B sediment core recovered from beneath the northwest part of the Ross ice shelf by the ANDRILL programme and demonstrate well-dated, approximately 40-kyr cyclic variations in ice-sheet extent linked to cycles in insolation influenced by changes in the Earth's axial tilt (obliquity) during the Pliocene. Our data provide direct evidence for orbitally induced oscillations in the WAIS, which periodically collapsed, resulting in a switch from grounded ice, or ice shelves, to open waters in the Ross embayment when planetary temperatures were up to approximately 3 degrees C warmer than today and atmospheric CO(2) concentration was as high as approximately 400 p.p.m.v. (refs 5, 6). The evidence is consistent with a new ice-sheet/ice-shelf model that simulates fluctuations in Antarctic ice volume of up to +7 m in equivalent sea level associated with the loss of the WAIS and up to +3 m in equivalent sea level from the East Antarctic ice sheet, in response to ocean-induced melting paced by obliquity. During interglacial times, diatomaceous sediments indicate high surface-water productivity, minimal summer sea ice and air temperatures above freezing, suggesting an additional influence of surface melt under conditions of elevated CO(2).
TL;DR: Long‐term, high‐dose UDCA therapy is associated with improvement in serum liver tests in PSC but does not improve survival and was associated with higher rates of serious adverse events.
TL;DR: In this article, the authors address why and how to model persons as contexts in longitudinal analysis, and provide an electronic appendix of syntax for estimating these models, as well as a discussion of the impact of constant, between-person sources of variation.
Abstract: Relationships among multiple variables over time are of interest in many developmental areas and are frequently examined using time-varying predictors in multilevel models. Yet an incomplete specification of time-varying predictors will usually result in biased model effects. Specifically, the impact of constant, between-person sources of variation must be differentiated from the impact of time-specific, within-person sources of variation - that is, persons should be modeled as contexts. The current didactic article expands upon previous work to address why and how to model persons as contexts in longitudinal analysis. An electronic appendix of syntax for estimating these models is also provided.
TL;DR: The results demonstrate that, over the long term, the loss of plant species propagates through food webs, greatly decreasing arthropod species richness, shifting a predator-dominated trophic structure to being herbivore dominated, and likely impacting ecosystem functioning and services.
Abstract: Plant diversity is predicted to be positively linked to the diversity of herbivores and predators in a foodweb. Yet, the relationship between plant and animal diversity is explained by a variety of competing hypotheses, with mixed empirical results for each hypothesis. We sampled arthropods for over a decade in an experiment that manipulated the number of grassland plant species. We found that herbivore and predator species richness were strongly, positively related to plant species richness, and that these relationships were caused by different mechanisms at herbivore and predator trophic levels. Even more dramatic was the threefold increase, from low- to high-plant species richness, in abundances of predatory and parasitoid arthropods relative to their herbivorous prey. Our results demonstrate that, over the long term, the loss of plant species propagates through food webs, greatly decreasing arthropod species richness, shifting a predator-dominated trophic structure to being herbivore dominated, and likely impacting ecosystem functioning and services.
TL;DR: This article offers research directions associated with the processes underlying professional development, including areas in need of investigation that can inform the early childhood education field in terms of how professional development efforts exert their influence and produce meaningful change in practitioners' skills, behaviors, and dispositions.
Abstract: In light of the current policy context, early childhood educators are being asked to have a complex understanding of child development and early education issues and provide rich, meaningful educational experiences for all children and families in their care. Accountability for outcomes is high, and resources for professional support are limited. Therefore, the early education field needs well-conducted empirical studies on which to base professional development practices. In this article, we offer research directions associated with the processes underlying professional development, including areas in need of investigation that can inform the early childhood education field in terms of how professional development efforts exert their influence and produce meaningful change in practitioners' skills, behaviors, and dispositions. The article highlights representative research from the professional development literature on its various forms/approaches and offers an agenda for research on the professional de...
TL;DR: In this paper, the authors investigated the relationship between authentic leadership, trust, positive psychological capital (PsyCap), and performance at the group level of analysis, and found that trust in management was found to mediate the relationship of authentic leadership and performance.
Abstract: This study investigates the relationship between authentic leadership, trust, positive psychological capital (PsyCap), and performance at the group level of analysis. Data were collected from a small Midwestern chain of retail clothing stores, a context in which the needs for both authentic leadership and a positive sales staff are integral to the firm’s performance. Constructs were aggregated to the store (group) level to test relationships between perceptions of authentic leadership, trust in management, positive psychological capital, and performance. Trust in management was found to mediate the relationship between PsyCap and performance and to partially mediate the relationship between authentic leadership and performance. Future discussions and implications are discussed.
TL;DR: World consumption of soybean ( Glycine max ) in 2008 was over 221 million metric tons, with approximately 50% of this supply coming from U.S. production, where soybean plantings on an annual basis are over 77 million ha.
Abstract: World consumption of soybean ( Glycine max ) in 2008 was over 221 million metric tons, with approximately 50% of this supply coming from U.S. production, where soybean plantings on an annual basis are over 77 million ha. Soybeans are desired on the marketplace as a valuable source of protein and oil
TL;DR: In this article, the authors examined whether follower characteristics moderate the relationship between transformational leadership and follower work engagement, and found that followers with higher follower characteristics were more likely to follow transformational leaders.
Abstract: This study examines whether follower characteristics moderate the relationship between transformational leadership and follower work engagement. Data were collected from 140 followers and their 48 ...
TL;DR: The data suggest that copper-transporting ATPases, CopA and ATP7A, in both bacteria and macrophage are unique determinants of bacteria survival and identify an unexpected role for copper at the host-pathogen interface.
TL;DR: Large-scale molecular dynamics simulation of transition between Wenzel state and Cassie state of water droplets on a periodic nanopillared hydrophobic surface and free-energy barrier separating the Wenzel andCassie state is shown.
Abstract: Water droplets on rugged hydrophobic surfaces typically exhibit one of the following two states: (i) the Wenzel state [Wenzel RN (1936) Ind Eng Chem 28:988–994] in which water droplets are in full contact with the rugged surface (referred as the wetted contact) or (ii) the Cassie state [Cassie, ABD, Baxter S (1944) Trans Faraday Soc 40:546–551] in which water droplets are in contact with peaks of the rugged surface as well as the “air pockets” trapped between surface grooves (the composite contact). Here, we show large-scale molecular dynamics simulation of transition between Wenzel state and Cassie state of water droplets on a periodic nanopillared hydrophobic surface. Physical conditions that can strongly affect the transition include the height of nanopillars, the spacing between pillars, the intrinsic contact angle, and the impinging velocity of water nanodroplet (“raining” simulation). There exists a critical pillar height beyond which water droplets on the pillared surface can be either in the Wenzel state or in the Cassie state, depending on their initial location. The free-energy barrier separating the Wenzel and Cassie state was computed on the basis of a statistical-mechanics method and kinetic raining simulation. The barrier ranges from a few tenths of kBT0 (where kB is the Boltzmann constant, and T0 is the ambient temperature) for a rugged surface at the critical pillar height to ≈8 kBT0 for the surface with pillar height greater than the length scale of water droplets. For a highly rugged surface, the barrier from the Wenzel-to-Cassie state is much higher than from Cassie-to-Wenzel state. Hence, once a droplet is trapped deeply inside the grooves, it would be much harder to relocate on top of high pillars.
TL;DR: In this paper, adaptive refinement algorithms for non-local method peridynamics were introduced for scaling of the micromodulus and horizon and discussed the particular features of adaptivity for which multiscale modeling and grid refinement are closely connected.
Abstract: We introduce here adaptive refinement algorithms for the non-local method peridynamics, which was proposed in (J. Mech. Phys. Solids 2000; 48:175–209) as a reformulation of classical elasticity for discontinuities and long-range forces. We use scaling of the micromodulus and horizon and discuss the particular features of adaptivity in peridynamics for which multiscale modeling and grid refinement are closely connected. We discuss three types of numerical convergence for peridynamics and obtain uniform convergence to the classical solutions of static and dynamic elasticity problems in 1D in the limit of the horizon going to zero. Continuous micromoduli lead to optimal rates of convergence independent of the grid used, while discontinuous micromoduli produce optimal rates of convergence only for uniform grids. Examples for static and dynamic elasticity problems in 1D are shown. The relative error for the static and dynamic solutions obtained using adaptive refinement are significantly lower than those obtained using uniform refinement, for the same number of nodes. Copyright © 2008 John Wiley & Sons, Ltd.
TL;DR: Uhl-Bien and McKelvey as mentioned in this paper focus on the adaptive function, an interactive process between adaptive leadership (an agentic behavior) and complexity dynamics (non-agentic social dynamics) that generates emergent outcomes (e.g., innovation, learning, adaptability) for the firm.
Abstract: We consider Complexity Leadership Theory [Uhl-Bien, M., Marion, R., & McKelvey, B. (2007). Complexity Leadership Theory: Shifting leadership from the industrial age to the knowledge era. The Leadership Quarterly .] in contexts of bureaucratic forms of organizing to describe how adaptive dynamics can work in combination with administrative functions to generate emergence and change in organizations. Complexity leadership approaches are consistent with the central assertion of the meso argument that leadership is multi-level, processual, contextual, and interactive. In this paper we focus on the adaptive function, an interactive process between adaptive leadership (an agentic behavior) and complexity dynamics (non-agentic social dynamics) that generates emergent outcomes (e.g., innovation, learning, adaptability) for the firm. Propositions regarding the actions of complexity leadership in bureaucratic forms of organizing are offered.
TL;DR: It is demonstrated that the profligacy of human CSE results in a variety of reactions that generate H2S from cysteine and homocysteine, which may contribute to the associated cardiovascular pathology in hyperhomocysteinemia.
13 Nov 2009
TL;DR: The need for positive leadership is not restricted to the societal/political level as mentioned in this paper, but also at all levels and types of organizations, with ever-advancing technology, growing round-the-clock global competitive pressures, and a very uncertain economic and ethical climate, leaders are facing the challenge of declining hope and confidence in themselves and their associates.
Abstract: In times of swirling negativity, as has occurred in recent years with the dotbombs, September 11 terrorism, gyrating stock values, and the meltdown of corporate ethics, society in general and organizations in particular turn to leaders for optimism and direction. Through the ages, especially in times of crisis and extreme turmoil, historical figures such as Alexander the Great, Washington, Gandhi, Churchill, Eleanor and Franklin Roosevelt, Mandela, and Rudy Guiliani have risen to the occasion to provide the positive leadership to move forward to address the problems confronting their communities and societies. This need for positive leadership is not restricted to the societal/political level. With ever-advancing technology, growing roundthe-clock global competitive pressures, and a very uncertain economic and ethical climate, leaders at all levels and types of organizations are facing the challenge of declining hope and confidence in themselves and their associates. Yet the understanding, developmental process, and implementation of needed positive leadership still remains largely underresearched by both the leadership and recently emerging positive psychology fields. Indeed, this is the only chapter in this book on positive organizational scholarship (POS) that deals directly with leadership, and there are no entries in the recently published Handbook of Positive Psychology (Snyder & Lopez, 2002). Co py ri gh t @ 20 03 . Be rr et tKo eh le r Pu bl is he rs .
TL;DR: This review uses information derived primarily using Bacillus subtilis and Escherichia coli to articulate how gram-positive pathogens, with emphasis on Staphylococcus aureus and Staphyllococcus epidermidis, regulate virulence determinant expression in response to a changing environment.
Abstract: Bacteria live in environments that are subject to rapid changes in the availability of the nutrients that are necessary to provide energy and biosynthetic intermediates for the synthesis of macromolecules. Consequently, bacterial survival depends on the ability of bacteria to regulate the expression of genes coding for enzymes required for growth in the altered environment. In pathogenic bacteria, adaptation to an altered environment often includes activating the transcription of virulence genes; hence, many virulence genes are regulated by environmental and nutritional signals. Consistent with this observation, the regulation of most, if not all, virulence determinants in staphylococci is mediated by environmental and nutritional signals. Some of these external signals can be directly transduced into a regulatory response by two-component regulators such as SrrAB; however, other external signals require transduction into intracellular signals. Many of the external environmental and nutritional signals that regulate virulence determinant expression can also alter bacterial metabolic status (e.g., iron limitation). Altering the metabolic status results in the transduction of external signals into intracellular metabolic signals that can be "sensed" by regulatory proteins (e.g., CodY, Rex, and GlnR). This review uses information derived primarily using Bacillus subtilis and Escherichia coli to articulate how gram-positive pathogens, with emphasis on Staphylococcus aureus and Staphylococcus epidermidis, regulate virulence determinant expression in response to a changing environment.
TL;DR: WWTP effluent was found to be a significant source of pharmaceutical loading to the receiving waters and Methamphetamine, an illicit pharmaceutical, was detected at all but one of the sampling locations, representing only the second report of methamphetamine detected in WW TP effluent and in streams impacted by WWTP effluents.
TL;DR: The algorithm is implemented in TinyOS and shown to be effective in adapting to local topology changes without incurring global overhead in the scheduling, and the effect of the time-varying nature of wireless links on the conflict-free property of DRAND-assigned time slots is evaluated.
Abstract: This paper presents a distributed implementation of RAND, a randomized time slot scheduling algorithm, called DRAND. DRAND runs in O(delta) time and message complexity where delta is the maximum size of a two-hop neighborhood in a wireless network while message complexity remains O(delta), assuming that message delays can be bounded by an unknown constant. DRAND is the first fully distributed version of RAND. The algorithm is suitable for a wireless network where most nodes do not move, such as wireless mesh networks and wireless sensor networks. We implement the algorithm in TinyOS and demonstrate its performance in a real testbed of Mica2 nodes. The algorithm does not require any time synchronization and is shown to be effective in adapting to local topology changes without incurring global overhead in the scheduling. Because of these features, it can also be used even for other scheduling problems such as frequency or code scheduling (for FDMA or CDMA) or local identifier assignment for wireless networks where time synchronization is not enforced. We further evaluate the effect of the time-varying nature of wireless links on the conflict-free property of DRAND-assigned time slots. This experiment is conducted on a 55-node testbed consisting of the more recent MicaZ sensor nodes.
North Shore-LIJ Health System1, University of Texas MD Anderson Cancer Center2, National Institutes of Health3, University of California, Davis4, University of California, San Francisco5, Harvard University6, University of Colorado Denver7, University of Nebraska–Lincoln8, University of Pittsburgh9, University of Alabama at Birmingham10, University of Toronto11, Celera Corporation12
TL;DR: The authors conducted a genome-wide association study of rheumatoid arthritis in 2,418 cases and 4,504 controls from North America and identified an association at the REL locus, encoding c-Rel, on chromosome 2p13 (rs13031237, P = 6.01 x 10(-10)).
Abstract: We conducted a genome-wide association study of rheumatoid arthritis in 2,418 cases and 4,504 controls from North America and identified an association at the REL locus, encoding c-Rel, on chromosome 2p13 (rs13031237, P = 6.01 x 10(-10)). Replication in independent case-control datasets comprising 2,604 cases and 2,882 controls confirmed this association, yielding an allelic OR = 1.25 (P = 3.08 x 10(-14)) for marker rs13031237 and an allelic OR = 1.21 (P = 2.60 x 10(-11)) for marker rs13017599 in the combined dataset. The combined dataset also provides definitive support for associations at both CTLA4 (rs231735; OR = 0.85; P = 6.25 x 10(-9)) and BLK (rs2736340; OR = 1.19; P = 5.69 x 10(-9)). c-Rel is an NF-kappaB family member with distinct functional properties in hematopoietic cells, and its association with rheumatoid arthritis suggests disease pathways that involve other recently identified rheumatoid arthritis susceptibility genes including CD40, TRAF1, TNFAIP3 and PRKCQ.