Showing papers by "University of Oklahoma published in 2004"
TL;DR: In this paper, the authors proposed a new framework that centers on the concept of progressive N limitation (PNL) for studying the interactions between C and N in terrestrial ecosystems, and examined conditions under which PNL may or may not constrain net primary production and carbon sequestration in terrestrial ecosystem.
Abstract: A highly controversial issue in global biogeochemistry is the regulation of terrestrial carbon (C) sequestration by soil nitrogen (N) availability. This controversy translates into great uncertainty in predicting future global terrestrial C sequestration. We propose a new framework that centers on the concept of progressive N limitation (PNL) for studying the interactions between C and N in terrestrial ecosystems. In PNL, available soil N becomes increasingly limiting as C and N are sequestered in long-lived plant biomass and soil organic matter. Our analysis focuses on the role of PNL in regulating ecosystem responses to rising atmospheric carbon dioxide concentration, but the concept applies to any perturbation that initially causes C and N to accumulate in organic forms. This article examines conditions under which PNL may or may not constrain net primary production and C sequestration in terrestrial ecosystems. While the PNL-centered framework has the potential to explain diverse experimental...
1,196 citations
TL;DR: Three subpopulations of mouse blood monocytes can be distinguished by differential expression of Ly-6C, CD43, CD11c, MBR, and CD62L, which differ in maturation stage and capacity to become recruited to inflammatory sites.
Abstract: Blood monocytes are well-characterized precursors for macrophages and dendritic cells. Subsets of human monocytes with differential representation in various disease states are well known. In contrast, mouse monocyte subsets have been characterized minimally. In this study we identify three subpopulations of mouse monocytes that can be distinguished by differential expression of Ly-6C, CD43, CD11c, MBR, and CD62L. The subsets share the characteristics of extensive phagocytosis, similar expression of M-CSF receptor (CD115), and development into macrophages upon M-CSF stimulation. By eliminating blood monocytes with dichloromethylene-bisphosphonate-loaded liposomes and monitoring their repopulation, we showed a developmental relationship between the subsets. Monocytes were maximally depleted 18 h after liposome application and subsequently reappeared in the circulation. These cells were exclusively of the Ly-6C(high) subset, resembling bone marrow monocytes. Serial flow cytometric analyses of newly released Ly-6C(high) monocytes showed that Ly-6C expression on these cells was down-regulated while in circulation. Under inflammatory conditions elicited either by acute infection with Listeria monocytogenes or chronic infection with Leishmania major, there was a significant increase in immature Ly-6C(high) monocytes, resembling the inflammatory left shift of granulocytes. In addition, acute peritoneal inflammation recruited preferentially Ly-6C(med-high) monocytes. Taken together, these data identify distinct subpopulations of mouse blood monocytes that differ in maturation stage and capacity to become recruited to inflammatory sites.
1,149 citations
TL;DR: Burnout is a psychological response to work stress that is characterized by emotional exhaustion, depersonalization, and reduced feelings of personal accomplishment as discussed by the authors, and it can be defined as a mental health disorder.
1,048 citations
TL;DR: The authors studied the influence of implicit and explicit knowledge transfer in the transfer of knowledge from the foreign parent to the international joint venture (IJV) managers and found that implicit learning is accumulative, assists in explaining explicit knowledge, and is enhanced by social embeddedness.
Abstract: Drawing on organizational learning and economic sociology, we address how relational embeddedness between the foreign parent and international joint venture (IJV) managers influences the type of knowledge (i.e., tacit and explicit) transferred to the IJV, and how the importance of relational embeddedness varies between young and mature IJVs. We also examine the influence of tacit and explicit knowledge on IJV performance. Our results show the importance that tie strength, trust, and shared values and systems play in the transfer of tacit knowledge, especially for mature IJVs. Our findings are consistent with Uzzi's tenets: tacit learning is accumulative, assists in explaining explicit knowledge, and is enhanced by social embeddedness. We also find that the influence of transferred tacit knowledge on IJV performance stems principally from its indirect effect on the learning of explicit knowledge.
965 citations
TL;DR: In this article, a quantitative meta-analysis of program evaluation efforts was conducted and it was found that well-designed creativity training programs typically induce gains in performance with these effects generalizing across criteria, settings, and target populations.
Abstract: Over the course of the last half century, numerous training programs intended to develop creativity capacities have been proposed. In this study, a quantitative meta‐analysis of program evaluation efforts was conducted. Based on 70 prior studies, it was found that well‐designed creativity training programs typically induce gains in performance with these effects generalizing across criteria, settings, and target populations. Moreover, these effects held when internal validity considerations were taken into account. An examination of the factors contributing to the relative effectiveness of these training programs indicated that more successful programs were likely to focus on development of cognitive skills and the heuristics involved in skill application, using realistic exercises appropriate to the domain at hand. The implications of these observations for the development of creativity through educational and training interventions are discussed along with directions for future research.
930 citations
TL;DR: Adolescents who expose themselves to greater amounts of video game violence were more hostile, reported getting into arguments with teachers more frequently, were more likely to be involved in physical fights, and performed more poorly in school.
904 citations
TL;DR: This paper used path analysis to test predictions of a model explaining the impact of students' perceptions of classroom structures (tasks, autonomy support and mastery and evaluation) on their selfefficacy, perceptions of the instrumentality of class work, and their achievement goals in a particular classroom setting.
826 citations
TL;DR: Three methods to detect biosurfactant production, drop collapse, oil spreading, and blood agar lysis, were compared for their ease of use and reliability in relation to the ability of the cultures to reduce surface tension.
791 citations
TL;DR: It is shown that polypod ferns (> 80% of living fern species) diversified in the Cretaceous, after angiosperms, suggesting perhaps an ecological opportunistic response to the diversification of angios perms, as angiosPerms came to dominate terrestrial ecosystems.
Abstract: The rise of angiosperms during the Cretaceous period is often portrayed as coincident with a dramatic drop in the diversity and abundance of many seed-free vascular plant lineages, including ferns. This has led to the widespread belief that ferns, once a principal component of terrestrial ecosystems, succumbed to the ecological predominance of angiosperms and are mostly evolutionary holdovers from the late Palaeozoic/early Mesozoic era. The first appearance of many modern fern genera in the early Tertiary fossil record implies another evolutionary scenario; that is, that the majority of living ferns resulted from a more recent diversification. But a full understanding of trends in fern diversification and evolution using only palaeobotanical evidence is hindered by the poor taxonomic resolution of the fern fossil record in the Cretaceous. Here we report divergence time estimates for ferns and angiosperms based on molecular data, with constraints from a reassessment of the fossil record. We show that polypod ferns (> 80% of living fern species) diversified in the Cretaceous, after angiosperms, suggesting perhaps an ecological opportunistic response to the diversification of angiosperms, as angiosperms came to dominate terrestrial ecosystems.
743 citations
TL;DR: In this article, a detailed analysis of a large published database of spectroscopic observations of Sr, Y, Zr, Ba, and Eu for Galactic stars at various metallicities, showing that the observed trends versus metallicity can be understood in light of a multiplicity of stellar neutron-capture components.
Abstract: In this paper we follow the Galactic enrichment of three easily observed light n-capture elements: Sr, Y, and Zr. Input stellar yields have been first separated into their respective main and weak s-process components and r-process component. The s-process yields from asymptotic giant branch (AGB) stars of low to intermediate mass are computed, exploring a wide range of efficiencies of the major neutron source, 13 C, and covering both disk and halo metallicities. AGB stars have been shown to reproduce the mains-component in the solar system, i.e., the s-process isotopic distribution of allheavy isotopes with atomic mass number A > 90, with a minor contribution to the light s-process isotopes up to A � 90. The concurrent weak s-process, which accounts for the major fraction of the light s-process isotopes in the solar system and occurs in massive stars by the operation of the 22 Ne neutron source, is discussed in detail. Neither the main s -n or the weaks-components are shown to contribute significantly to the neutron-capture element abundances observed in unevolved halo stars. Knowing the s-process distribution at the epoch of the solar system formation, we first employed the r-process residuals method to infer the isotopic distribution of the r-process. We assumed a primary r-process production in the Galaxy from moderately massive Type II supernovae that best reproduces the observational Galactic trend of metallicity versus Eu, an almost pure r-process element. We present a detailed analysis of a large published database of spectroscopic observations of Sr, Y, Zr, Ba, and Eu for Galactic stars at various metallicities, showing that the observed trends versus metallicity can be understood in light of a multiplicity of stellar neutron-capture components. Spectroscopic observations of the Sr, Y, and Zr to Ba and Eu abundance ratios versus metallicity provide useful diagnostics of the types of neutron-capture processes forming Sr, Y, and Zr. In particular, the observed [Sr, Y, Zr/Ba, Eu] ratio is clearly not flat at low metallicities, as we would expect if Ba, Eu and Sr, Y, Zr all had the same r-process nucleosynthetic origin. We discuss our chemical evolution predictions, taking into account the interplay between different processes to produce Sr-Y-Zr. Making use of the very r-process‐rich and very metal-poor stars like CS 22892� 052 and CS 31082� 001, we find hints and discuss the possibility of a primary process in low-metallicity massive stars, different from the ‘‘classical s-process’’ and from the ‘‘classical r-process’’ that we tentatively define LEPP (lighter element primary process). This allows us to revise the estimates of the r-process contributions to the solar Sr, Y, and Zr abundances, as well as of the contribution to the s-only isotopes 86 Sr, 87 Sr, and 96 Mo. Subject headings: Galaxy: abundances — Galaxy: evolution — nuclear reactions, nucleosynthesis, abundances — stars: abundances — stars: AGB and post-AGB
653 citations
TL;DR: Although the risk of surgery is an important consideration, splenectomy provides a high frequency of durable responses for adult patients with ITP and the ability to predict who will respond, and the frequency of surgical complications all remain uncertain.
TL;DR: Investigation of how thoughts about death and the 9/11 terrorist attacks influence Americans’ attitudes toward current U.S. President George W. Bush found that reminding people of their own mortality increased support for Bush and his counterterrorism policies.
Abstract: According to terror management theory, heightened concerns about mortality should intensify the appeal of charismatic leaders. To assess this idea, we investigated how thoughts about death and the 9/11 terrorist attacks influence Americans’ attitudes toward current U.S. President George W. Bush. Study 1 found that reminding people of their own mortality (mortality salience) increased support for Bush and his counterterrorism policies. Study 2 demonstrated that subliminal exposure to 9/11-related stimuli brought death-related thoughts closer to consciousness. Study 3 showed that reminders of both mortality and 9/11 increased support for Bush. In Study 4, mortality salience led participants to become more favorable toward Bush and voting for him in the upcoming election but less favorable toward Presidential candidate John Kerry and voting for him. Discussion focused on the role of terror management processes in allegiance to charismatic leaders and political decision making.
Cleveland Clinic1, Duke University2, Henry Ford Health System3, Harvard University4, University of Oklahoma5, Baylor College of Medicine6, New York University7, University of Connecticut8, Kaiser Permanente9, University of North Carolina at Chapel Hill10, University of Pennsylvania11, University of Cincinnati12
TL;DR: An early invasive management strategy appears to be reserved for patients without significant comorbidities and those cared for by cardiologists and is associated with a lower risk of in-hospital mortality.
Abstract: ContextThe American College of Cardiology/American Heart Association (ACC/AHA)
guidelines for the management of non–ST-segment elevation acute coronary
syndromes (NSTE ACS) recommend early invasive management for high-risk patients,
given the benefits with this approach demonstrated in randomized clinical
trials.ObjectivesTo determine the use and predictors of early invasive management strategies
(cardiac catheterization <48 hours following presentation) in high-risk
patients with NSTE ACS and to examine the association of early invasive management
with mortality.Design, Setting, and PatientsThe CRUSADE (Can Rapid Risk Stratification of Unstable Angina Patients
Suppress Adverse Outcomes With Early Implementation of the ACC/AHA Guidelines)
Quality Improvement Initiative evaluated care patterns and outcomes for 17 926
high-risk NSTE ACS patients (positive cardiac markers and/or ischemic electrocardiographic
changes) based on ACC/AHA guidelines recommendations at 248 US hospitals with
catheterization and revascularization facilities between March 2000 and September
2002.Main Outcome MeasuresUse of early invasive management within 48 hours of presentation, predictors
of early invasive management, and in-hospital mortality.ResultsOf the 17 926 patients analyzed, 8037 (44.8%) underwent early cardiac
catheterization less than 48 hours following presentation. Predictors of early
invasive management included cardiology care, younger age, lack of prior or
current congestive heart failure, lack of renal insufficiency, ischemic electrocardiographic
changes, positive cardiac markers, white race, and male sex. Patients treated
with early invasive management were more likely to be treated with medications
and interventions recommended by the ACC/AHA guidelines and had a lower risk
of in-hospital mortality after adjusting for differences in clinical characteristics
and after comparing propensity-matched pairs (2.5% vs 3.7%, P<.001).ConclusionsAn early invasive management strategy is not utilized in the majority
of high-risk patients with NSTE ACS. This strategy appears to be reserved
for patients without significant comorbidities and those cared for by cardiologists
and is associated with a lower risk of in-hospital mortality.
TL;DR: The DMI1 (does not make infections) gene encodes a novel protein with low global similarity to a ligand-gated cation channel domain of archaea that is highly conserved in angiosperms and ancestral to land plants.
Abstract: Legumes form symbiotic associations with both mycorrhizal fungi and nitrogen-fixing soil bacteria called rhizobia. Several of the plant genes required for transduction of rhizobial signals, the Nod factors, are also necessary for mycorrhizal symbiosis. Here, we describe the cloning and characterization of one such gene from the legume Medicago truncatula. The DMI1 (does not make infections) gene encodes a novel protein with low global similarity to a ligand-gated cation channel domain of archaea. The protein is highly conserved in angiosperms and ancestral to land plants. We suggest that DMI1 represents an ancient plant-specific innovation, potentially enabling mycorrhizal associations.
TL;DR: In this paper, the authors developed measurement scales for a supply chain orientation (SCO) and supply chain management (SCM), and established the relationship between a SCO, SCM, and business performance.
Abstract: To investigate the construct of Supply Chain Management and its antecedent construct of a Supply Chain Orientation, reliable, valid scales of each are needed. In this study, we developed measurement scales for a supply chain orientation (SCO) and supply chain management (SCM). Validity and reliability of the developed scales were established and the relationship between a SCO, SCM, and business performance was also established, providing evidence of nomological validity. The implications of these findings for managers and researchers are discussed.
TL;DR: The more entrepreneurial value orientations of the most recent Chinese generations appear to be compatible with organizational changes currently under way in China's state-owned sector.
Abstract: This study investigated the generation cohort value orientations of 774 Chinese and 784 U.S. managers and professionals. The three Chinese generations (Consolidation, Cultural Revolution, Social Reform) since the establishment of Communist China were significantly more open to change and self-enhancement but less conservative and self-transcendent than the Republican Era generation. The value orientations of U.S. generations (Generation X, Baby Boomer, Silent generation) followed an age-related pattern with the exception of self-transcendence values. The least similar value orientations were between Chinese and U.S. generations that had grown up during Communist China's closed-door policy. The more entrepreneurial value orientations of the most recent Chinese generations appear to be compatible with organizational changes currently under way in China's state-owned sector.
TL;DR: The results of this systematic analysis of nutrients used by E. coli MG1655 to colonize the mouse intestine are intriguing in light of the nutrient-niche hypothesis, which states that the ecological niches within the intestine are defined by nutrient availability.
Abstract: Whole-genome expression profiling revealed Escherichia coli MG1655 genes induced by growth on mucus, conditions designed to mimic nutrient availability in the mammalian intestine. Most were nutritional genes corresponding to catabolic pathways for nutrients found in mucus. We knocked out several pathways and tested the relative fitness of the mutants for colonization of the mouse intestine in competition with their wild-type parent. We found that only mutations in sugar pathways affected colonization, not phospholipid and amino acid catabolism, not gluconeogenesis, not the tricarboxylic acid cycle, and not the pentose phosphate pathway. Gluconate appeared to be a major carbon source used by E. coli MG1655 to colonize, having an impact on both the initiation and maintenance stages. N-acetylglucosamine and N-acetylneuraminic acid appeared to be involved in initiation, but not maintenance. Glucuronate, mannose, fucose, and ribose appeared to be involved in maintenance, but not initiation. The in vitro order of preference for these seven sugars paralleled the relative impact of the corresponding metabolic lesions on colonization: gluconate > N-acetylglucosamine > N-acetylneuraminic acid = glucuronate > mannose > fucose > ribose. The results of this systematic analysis of nutrients used by E. coli MG1655 to colonize the mouse intestine are intriguing in light of the nutrient-niche hypothesis, which states that the ecological niches within the intestine are defined by nutrient availability. Because humans are presumably colonized with different commensal strains, differences in nutrient availability may provide an open niche for infecting E. coli pathogens in some individuals and a barrier to infection in others.
TL;DR: This work develops a model of fit-as-gestalt, drawing from literatures on strategy, governance, interorganizational relationships, and outsourcing, and indicates the superiority of the configurational approach over universalistic and contingency perspectives in explaining outsourcing success.
Abstract: Focus on individual outsourcing decisions in IT research has often yielded contradictory findings and recommendations. To address these contradictions, we investigate a holistic, configurational approach with the prevailing universalistic or contingency perspectives in exploring the effects of IT outsourcing strategies on outsourcing success. Based on residual rights theory, we begin by identifying three dimensions of IT outsourcing strategies: degree of integration, allocation of control, and performance period. We then develop a model of fit-as-gestalt, drawing from literatures on strategy, governance, interorganizational relationships, and outsourcing.Next, based on data from 311 firms in South Korea, we test universalistic and contingency perspectives in explaining the relationship between IT outsourcing strategies and outsourcing success. We then identify three congruent patterns, or gestalts, of IT outsourcing strategies. We term these strategiesindependent, arm's-length, andembedded strategies. To establish the predictive validity of these gestalts and the viability of a configurational perspective, we then explore the effects of these congruent gestalts vis-A -vis noncongruent patterns on three dimensions of outsourcing success:strategic competence,cost efficiency, andtechnology catalysis. We also contrast the effects of each of the three gestalts on each of the three dimensions of outsourcing success. Our findings indicate the superiority of the configurational approach over universalistic and contingency perspectives in explaining outsourcing success.
TL;DR: Comparisons of sequenced regions of the model legume Medicago truncatula with those of the diploid Lotus japonicus and the polyploid Glycine max suggest that comparative mapping may have considerable utility for basic and applied research in the legumes, although its predictive value is likely to be tempered by phylogenetic distance and genome duplication.
Abstract: Legumes are simultaneously one of the largest families of crop plants and a cornerstone in the biological nitrogen cycle. We combined molecular and phylogenetic analyses to evaluate genome conservation both within and between the two major clades of crop legumes. Genetic mapping of orthologous genes identifies broad conservation of genome macrostructure, especially within the galegoid legumes, while also highlighting inferred chromosomal rearrangements that may underlie the variation in chromosome number between these species. As a complement to comparative genetic mapping, we compared sequenced regions of the model legume Medicago truncatula with those of the diploid Lotus japonicus and the polyploid Glycine max. High conservation was observed between the genomes of M. truncatula and L. japonicus, whereas lower levels of conservation were evident between M. truncatula and G. max. In all cases, conserved genome microstructure was punctuated by significant structural divergence, including frequent insertion/deletion of individual genes or groups of genes and lineage-specific expansion/contraction of gene families. These results suggest that comparative mapping may have considerable utility for basic and applied research in the legumes, although its predictive value is likely to be tempered by phylogenetic distance and genome duplication.
TL;DR: In this paper, the authors demonstrate the importance of examining the combined effects of the gradually rising concentration of atmospheric CO2 and the climatic change that attends it, and propose an alternative approach to gain a thorough understanding of the modes of action of single factors, and rely on our understanding (as represented in models) to inform us of the probable interactions.
Abstract: Summary
Analyses of ecosystem responses to global change must embrace the reality of multiple, interacting environmental factors. Ecosystem models demonstrate the importance of examining the combined effects of the gradually rising concentration of atmospheric CO2 and the climatic change that attends it. Models to forecast future changes need data support to be useful, and data–model fusion has become essential in global change research. There is a wealth of information on plant responses to CO2 and temperature, but there have been few ecosystem-scale experiments investigating the combined or interactive effects of CO2 enrichment and warming. Factorial experiments to investigate interactions can be difficult to design, conduct, and interpret, and their results may not support predictions at the ecosystem scale – in the context of global change they will always be case studies. An alternative approach is to gain a thorough understanding of the modes of action of single factors, and rely on our understanding (as represented in models) to inform us of the probable interactions. Multifactor (CO2 × temperature) experiments remain important, however, for testing concepts, demonstrating the reality of multiple-factor influences, and reminding us that surprises can be expected.
Texas A&M University1, University of Mary Hardin–Baylor2, University of South Florida3, Dana Corporation4, University of Queensland5, Baylor University6, University of Oklahoma7, Mercer University8, Northwestern University9, University of Akron10, University of Mount Union11, Kansas State University12, Florida State University College of Arts and Sciences13
TL;DR: This paper is a five year update of the sports nutrition review article published as the lead paper to launch the JISSN and presents a well-referenced overview of the current state of the science related to how to optimize training and athletic performance through nutrition.
Abstract: Sports nutrition is a constantly evolving field with hundreds of research papers published annually. For this reason, keeping up to date with the literature is often difficult. This paper is a five year update of the sports nutrition review article published as the lead paper to launch the JISSN in 2004 and presents a well-referenced overview of the current state of the science related to how to optimize training and athletic performance through nutrition. More specifically, this paper provides an overview of: 1.) The definitional category of ergogenic aids and dietary supplements; 2.) How dietary supplements are legally regulated; 3.) How to evaluate the scientific merit of nutritional supplements; 4.) General nutritional strategies to optimize performance and enhance recovery; and, 5.) An overview of our current understanding of the ergogenic value of nutrition and dietary supplementation in regards to weight gain, weight loss, and performance enhancement. Our hope is that ISSN members and individuals interested in sports nutrition find this review useful in their daily practice and consultation with their clients.
TL;DR: In this article, the authors reported the observation of the X(3872) in the J/psipi(+)pi(-) channel with decaying to mu(+)mu(-), in p (p) over bar collisions at roots=1.96 TeV.
Abstract: We report the observation of the X(3872) in the J/psipi(+)pi(-) channel, with J/psi decaying to mu(+)mu(-), in p (p) over bar collisions at roots=1.96 TeV. Using approximately 230 pb(-1) of data collected with the Run II D0 detector, we observe 522+/-100 X(3872) candidates. The mass difference between the X(3872) state and the J/psi is measured to be 774.9+/-3.1(stat)+/-3.0(syst) MeV/c(2). We have investigated the production and decay characteristics of the X(3872) and find them to be similar to those of the psi(2S) state.
TL;DR: In this paper, a least square approach has been used to determine multiplicative scaling factors for harmonic vibrational frequencies to facilitate comparison with experimentally observed frequencies, and the percentage of calculated frequencies that deviate less than 3% from the experimental frequencies is 93−97% for B3LYP and 88−92% for MP2 when quadruple-ζ level basis sets are used.
Abstract: A least-squares approach has been used to determine multiplicative scaling factors for harmonic vibrational frequencies to facilitate comparison with experimentally observed frequencies. The harmonic frequencies were calculated using several of the most popular quantum chemical methods (HF, MP2, and B3LYP) and the correlation consistent family of basis sets (cc-pVxZ and aug-cc-pVxZ, where x = D(2), T(3), or Q(4)). Calculations were performed on 41 organic molecules for which fundamental frequencies are well established. When the derived scaling factors are applied, the percentage of calculated frequencies that deviate less than 3% from the experimental frequencies is 93−97% for B3LYP and 88−92% for MP2 when quadruple-ζ level basis sets are used. Similarly, scaling factors were determined for computing the vibrational components of the thermal contributions to enthalpy and entropy. An additional set of molecules was used in calculating scaling factors for the zero-point vibrational energy.
TL;DR: Safety was demonstrated in this series of patients with pacemakers at 1.5-T and threshold changes were unrelated to cardiac chamber, anatomical location, peak SAR, and time from lead implant to the MRI examination.
TL;DR: In this paper, a theoretically grounded model of motivation and self-regulation that places personally valued future goals at its core is presented, and the implications of this model for research and intervention are discussed.
Abstract: This article presents a theoretically grounded model of motivation and self-regulation that places personally valued future goals at its core. We attempt to integrate two lines of theorizing and research that have been relatively independent of one another: the social–cognitive perspective on self-regulation (e.g., Bandura, A., 1986) and theories of more future-oriented self-regulation (e.g., Markus, H., and Nurius, P., Am. Psychol. 41: 954–969, 1986; 1986; Nutin, J., Motivation, Planning, and Action: A Relational Theory of Behavior Dynamics, Erlbaum, Hillsdale, NJ, 1984; Raynor, J. O., Motivation and Achievement, Winston, & Sons, New York, Chap. 7, pp. 121–154, 1974). We argue that personally valued future goals influence proximal self-regulation through their impact in the development of proximal subgoals leading to future goal attainment. The development of a system of proximal subgoals increases the likelihood that proximal tasks are perceived as instrumental to attaining future goals. Proximal tasks that are perceived as instrumental to reaching personally valued future goals have greater overall incentive value and meaning than proximal tasks lacking this instrumental relationship, and their impact on task engagement is correspondingly greater. Research supporting these claims is reviewed and the implications of this model of future-oriented self-regulation for research and intervention are discussed.
TL;DR: In this article, the abundances of the elements La and Eu have been determined over the stellar metallicity range -3 < [Fe/H] < +0.3 in 159 giant and dwarf stars.
Abstract: From newly obtained high-resolution, high signal-to-noise ratio spectra the abundances of the elements La and Eu have been determined over the stellar metallicity range -3 < [Fe/H] < +0.3 in 159 giant and dwarf stars. Lanthanum is predominantly made by the s-process in the solar system, while Eu owes most of its solar system abundance to the r-process. The changing ratio of these elements in stars over a wide metallicity range traces the changing contributions of these two processes to the Galactic abundance mix. Large s-process abundances can be the result of mass transfer from very evolved stars, so to identify these cases we also report carbon abundances in our metal-poor stars. Results indicate that the s-process may be active as early as [Fe/H] = -2.6, although we also find that some stars as metal-rich as [Fe/H] = -1 show no strong indication of s-process enrichment. There is a significant spread in the level of s-process enrichment even at solar metallicity.
University of Wyoming1, University of Oregon2, Oak Ridge National Laboratory3, Northern Arizona University4, Marine Biological Laboratory5, University of Nevada, Reno6, Oregon State University7, University of Oklahoma8, Smithsonian Environmental Research Center9, Lund University10, Colorado State University11
TL;DR: In this article, the current status of below-ground responses to elevated CO2 and temperature and potential feedback effects, methodological challenges, and approaches to integrating models and measurements are discussed, as well as approaches to integrate models and data to predict long-term, net carbon storage in ecosystems.
Abstract: Rising atmospheric CO2 and temperatures are probably altering ecosystem carbon cycling, causing both positive and negative feedbacks to climate. Below-ground processes play a key role in the global carbon (C) cycle because they regulate storage of large quantities of C, and are potentially very sensitive to direct and indirect effects of elevated CO2 and temperature. Soil organic matter pools, roots and associated rhizosphere organisms all have distinct responses to environmental change drivers, although availability of C substrates will regulate all the responses. Elevated CO2 increases C supply below-ground, whereas warming is likely to increase respiration and decomposition rates, leading to speculation that these effects will moderate one another. However, indirect effects on soil moisture availability and nutrient supply may alter processes in unexpected directions. Detailed, mechanistic understanding and modelling of below-ground flux components, pool sizes and turnover rates is needed to adequately predict long-term, net C storage in ecosystems. In this synthesis, we discuss the current status of below-ground responses to elevated CO2 and temperature and potential feedback effects, methodological challenges, and approaches to integrating models and measurements.
TL;DR: In this paper, a review examines the intersection between the fields of leadership and entrepreneurship with an emphasis on how the path taken by leadership research can inform entrepreneurship and possibly lessen this young field's growing pains.
Abstract: Leadership scholars are quite familiar with the often convoluted and problematic path that leadership theory has taken. Despite these challenges, leadership is currently considered a “mature field” [Hunt, J.G., & Dodge, G.E. (2000). Leader Deja Vu all over again. The Leadership Quarterly, 11 (4), 453–458] even though this maturity has not been achieved without considerable growing pains. Similar to the path that leadership scholars have taken, those who study entrepreneurship also struggle with issues associated with a field in its early stages. This review examines the intersection between the fields of leadership and entrepreneurship with an emphasis on how the path taken by leadership research can inform entrepreneurship and possibly lessen this young field's growing pains. We first identify several areas where these fields theoretically converge (both in the models employed and the research questions addressed). Next, we take a historical perspective of leadership and entrepreneurship by identifying the life cycle stage of each construct or domain. Finally, we conclude with some thoughts on how the entrepreneurship field may avoid (or is avoiding) the pitfalls experienced by those who study leadership.
TL;DR: In this article, the authors review the recent controversy concerning temperature corrections to the Casimir force between real metal surfaces, and present a summary of new improvements to the proximity force approximation and a synopsis of the current experimental situation.
Abstract: The phenomena implied by the existence of quantum vacuum fluctuations, grouped under the title of the Casimir effect, are reviewed, with emphasis on new results discovered in the past four years. The Casimir force between parallel plates is rederived as the strong-coupling limit of δ-function potential planes. The role of surface divergences is clarified. A summary of effects relevant to measurements of the Casimir force between real materials is given, starting from a geometrical optics derivation of the Lifshitz formula, and including a rederivation of the Casimir–Polder forces. A great deal of attention is given to the recent controversy concerning temperature corrections to the Casimir force between real metal surfaces. A summary of new improvements to the proximity force approximation is given, followed by a synopsis of the current experimental situation. New results on Casimir self-stress are reported, again based on δ-function potentials. Progress in understanding divergences in the self-stress of dielectric bodies is described, in particular the status of a continuing calculation of the self-stress of a dielectric cylinder. Casimir effects for solitons, and the status of the so-called dynamical Casimir effect, are summarized. The possibilities of understanding dark energy, strongly constrained by both cosmological and terrestrial experiments, in terms of quantum fluctuations are discussed. Throughout, the centrality of quantum vacuum energy in fundamental physics is emphasized.
TL;DR: In this paper, the key conclusions emerging from the various articles presented in this two-part special issue are examined with respect to the nature of the leader, the leader's interactions with followers, the effective direction of followers' activities, and the leader interactions with the organization.
Abstract: The need for innovation in organizations has resulted in a new focus on the role of leaders in shaping the nature and success of creative efforts. The various articles prepared for these special issues of The Leadership Quarterly on Leading for Innovation all, in one way or another, underscored the impact of leadership on the nature and success of creative efforts. These articles, however, also indicate that the leadership of creative efforts is an unusually complex activity. In the present article, the key conclusions emerging from the various articles presented in this two-part special issue are examined with respect to the nature of the leader, the leader's interactions with followers, the effective direction of followers' activities, and the leader's interactions with the organization. Directions for future research, along with certain metatheoretical issues, are discussed.