Showing papers by "University of Missouri published in 2000"
TL;DR: In this paper, the authors explored the hypothesis that daily variations may be understood in terms of the degree to which three basic needs (autonomy, competence, and relatedness) are satisfied in daily activity.
Abstract: Emotional well-being is most typically studied in trait or trait-like terms, yet a growing literature indicates that daily (within-person) fluctuations in emotional well-being may be equally important. The present research explored the hypothesis that daily variations may be understood in terms of the degree to which three basic needs—autonomy, competence, and relatedness—are satisfied in daily activity. Hierarchical linear models were used to examine this hypothesis across 2 weeks of daily activity and well-being reports controlling for trait-level individual differences. Results strongly supported the hypothesis. The authors also examined the social activities that contribute to satisfaction of relatedness needs. The best predictors were meaningful talk and feeling understood and appreciated by interaction partners. Finally, the authors found systematic day-of-the-week variations in emotional well-being and need satisfaction. These results are discussed in terms of the importance of daily activities and...
1,845 citations
TL;DR: This paper found that prospective job applicants are more likely to pursue jobs from socially responsible firms than from firms with poor social performance reputations, and that job applicants have higher self-images when working for socially responsive firms over their less responsive counterparts.
Abstract: Several researchers have suggested that a talented, quality workforce will become a more important source of competitive advantage for firms in the future. Drawing on social identity theory and signaling theory, the authors hypothesize that firms can use their corporate social performance (CSP) activities to attract job applicants. Specifically, signaling theory suggests that a firm’s CSP sends signals to prospective job applicants about what it would be like to work for a firm. Social identity theory suggests that job applicants have higher self-images whenworking for socially responsive firms over their less responsive counterparts. The authors conducted an experiment in which they manipulated CSP and found that prospective job applicants are more likely to pursue jobs from socially responsible firms than from firms with poor social performance reputations. The implications of these findings for academicians and practitioners alike are discussed.
1,772 citations
TL;DR: The purpose of this paper is to propose a metatheory of problem solving in order to initiate dialogue and research rather than offering a definitive answer regarding its processes.
Abstract: Problem solving is generally regarded as the most important cognitive activity in everyday and professional contexts. Most people are required to and rewarded for solving problems. However, learning to solve problems is too seldom required in formal educational settings, in part, because our understanding of its processes is limited. Instructional-design research and theory has devoted too little attention to the study of problem-solving processes. In this article, I describe differences among problems in terms of their structuredness, domain specificity (abstractness), and complexity. Then, I briefly describe a variety of individual differences (factors internal to the problem solver) that affect problem solving. Finally, I articulate a typology of problems, each type of which engages different cognitive, affective, and conative processes and therefore necessitates different instructional support. The purpose of this paper is to propose a metatheory of problem solving in order to initiate dialogue and research rather than offering a definitive answer regarding its processes.
1,666 citations
01 Oct 2000
TL;DR: In this article, the authors investigated TAM for work-related tasks with the World Wide Web as the application and found that ease of understanding and ease of finding predict ease of use, and information quality predicts usefulness for revisited sites.
Abstract: The technology acceptance model (TAM) proposes that ease of use and usefulness predict applications usage. The current research investigated TAM for work-related tasks with the World Wide Web as the application. One hundred and sixty-three subjects responded to an e-mail survey about a Web site they access often in their jobs. The results support TAM. They also demonstrate that (1) ease of understanding and ease of finding predict ease of use, and that (2) information quality predicts usefulness for revisited sites. In effect, the investigation applies TAM to help Web researchers, developers, and managers understand antecedents to users' decisions to revisit sites relevant to their jobs.
1,362 citations
TL;DR: This article found no evidence that economic dependence causes Big Five auditors to report more favorably for larger clients in their offices, and they do find that Big 5 auditors report more conservatively for large clients, suggesting that reputation protection dominates auditor behavior.
1,187 citations
TL;DR: Evidence is found that estrogen/ERα signaling is critical in female and male WAT; obesity in αERKO males involves a mechanism of reduced energy expenditure rather than increased energy intake.
Abstract: Estrogen regulates the amount of white adipose tissue (WAT) in females, but its role in males and whether WAT effects involve estrogen receptor-α (ERα) or ERβ were unclear. We analyzed the role of ERα in WAT and brown adipose tissue by comparing these tissues in wild-type (WT) and ERα-knockout (αERKO) male and female mice. Brown adipose tissue weight was similar in αERKO and WT males at all ages. Progressive increases in WAT were seen in αERKO males with advancing age. Epididymal, perirenal, and inguinal WAT weighed 139–185% more in αERKO than in WT males by 270–360 days of age. Epididymal and perirenal adipocyte size was increased 20% in αERKO males. Adipocyte number was 82–168% greater in fat pads of αERKO vs. WT males. Compared with WT, 90-day-old αERKO females had increases in fat pad weights (54–103%), adipocyte size, and number. Both αERKO males and females had insulin resistance and impaired glucose tolerance, similar to humans lacking ERα or aromatase. Energy intake was equal in WT and αERKO males, indicating that obesity was not induced by hyperphagia. In contrast, energy expenditure was reduced by 11% in αERKO compared with WT males, indicating that altered energy expenditure may be important for the observed obesity. In summary, ERα absence causes adipocyte hyperplasia and hypertrophy, insulin resistance, and glucose intolerance in both sexes. These results are evidence that estrogen/ERα signaling is critical in female and male WAT; obesity in αERKO males involves a mechanism of reduced energy expenditure rather than increased energy intake.
1,154 citations
TL;DR: Positive behavior support (PBS) and functional behavioral assessment (FBA) are two significant concepts of the 1997 amendments to the Individuals with Disabilities Education Act (IDEA) as discussed by the authors.
Abstract: Positive behavior support (PBS) and functional behavioral assessment (FBA) are two significant concepts of the 1997 amendments to the Individuals with Disabilities Education Act. These two concepts...
1,013 citations
TL;DR: In this article, the authors employ a Bayesian dynamic latent factor model to estimate common components in main macroeconomic aggregates (output, consumption and investment) in a sixty-country sample covering seven regions of the world.
Abstract: The paper investigates the common dynamic properties of business cycle fluctuations across countries, regions and the world. We employ a Bayesian dynamic latent factor model to estimate common components in main macroeconomic aggregates (output, consumption and investment) in a sixty-country sample covering seven regions of the world. In particular, we simultaneously estimate (i) a dynamic factor common to all aggregates/regions/countries (the world factor); (ii) a set of 7 regional dynamic factors common across aggregates within a region; (iii) 60 country factors to capture dynamic comovement across aggregates within each country; (iv) and a component for each aggregate that captures idiosyncratic dynamics. We decompose the volatility in each aggregate into the fraction due to the world, region, country, and idiosyncratic components. The results indicate that the world factor is an important source of volatility for aggregates in most countries, providing evidence for a world business cycle. We find that the region-specific factor plays only a minor role in explaining fluctuations in economic activity. While the world and regional factors together account for a larger share of fluctuations in output than in consumption, the country factor along with the idiosyncratic factor play a much larger role in explaining investment dynamics. We also compare and contrast how the three aggregates in each country relate to the world, region and country factors, and document similarities and differences across regions, countries and aggregates. We link the empirical results to the economic structure of the countries in the sample.
967 citations
TL;DR: Evidence suggests that reduced zinc availability affects membrane signaling systems and intracellular second messengers that coordinate cell proliferation in response to IGF-I, and may directly regulate DNA synthesis through these systems.
Abstract: The inhibition of growth is a cardinal symptom of zinc deficiency. In animals fed a zinc-inadequate diet, both food intake and growth are reduced within 4-5 d. Despite the concomitant reduction in food intake and growth, reduced energy intake is not the limiting factor in growth, because force-feeding a zinc-inadequate diet to animals fails to maintain growth. Hence, food intake and growth appear to be regulated by zinc through independent, although well coordinated, mechanisms. Despite the long-term study of zinc metabolism, the first limiting role of zinc in cell proliferation remains undefined. Zinc participates in the regulation of cell proliferation in several ways; it is essential to enzyme systems that influence cell division and proliferation. Removing zinc from the extracellular milieu results in decreased activity of deoxythymidine kinase and reduced levels of adenosine(5')tetraphosphate(5')-adenosine. Hence, zinc may directly regulate DNA synthesis through these systems. Zinc also influences hormonal regulation of cell division. Specifically, the pituitary growth hormone (GH)-insulin-like growth factor-I (IGF-I) axis is responsive to zinc status. Both increased and decreased circulating concentrations of GH have been observed in zinc deficiency, although circulating IGF-I concentrations are consistently decreased. However, growth failure is not reversed by maintaining either GH or IGF-I levels through exogenous administration, which suggests the defect occurs in hormone signaling. Zinc appears to be essential for IGF-I induction of cell proliferation; the site of regulation is postreceptor binding. Overall, the evidence suggests that reduced zinc availability affects membrane signaling systems and intracellular second messengers that coordinate cell proliferation in response to IGF-I.
790 citations
TL;DR: This review compiles and evaluates existing scientific information on the use, limitations, and procedural considerations for EROD activity (a catalytic measurement of cytochrome P4501A induction) as a biomarker in fish.
Abstract: This review compiles and evaluates existing scientific information on the use, limitations, and procedural considerations for EROD activity (a catalytic measurement of cytochrome P4501A induction) ...
789 citations
TL;DR: In this paper, the authors measure the growth in open market stock repurchases and the manner in which stock repurchase and dividends are used by U.S. corporations, and find that stock buybacks are very procyclical, while dividends increase steadily over time.
TL;DR: In this article, the authors analyzed the levels and determinants of job satisfaction in a cross-national setting using the latest Work Orientations data set from the International Social Survey Program (ISSP).
Abstract: The aim of this paper is to analyze the levels and determinants of job satisfaction in a cross-national setting. This aim is accomplished using the latest Work Orientations data set from the International Social Survey Program (ISSP). The survey was conducted in 1997 and, in this paper, data for 21 countries are used. The main results are: (i) workers in all countries are quite satisfied; this result also applies to the five Eastern European countries analyzed here. (ii) Denmark is the country with the highest job-satisfaction level. The United States is ranked seventh, Great Britain fifteenth, Japan nineteenth, and Russia twentieth. (iii) A comparison with the 1989 ISSP data set reveals that job satisfaction has declined in Germany and the United States in the 1990s. (iv) Using a bottom-up psychological model, in which we compare work-role inputs (e.g., effort) with work-role outputs (e.g., pay), we try to explain cross-national differences. Countries with high work-role outputs, in general, have a high job-satisfaction ranking, and vice versa. (v) Having an interesting job and having good relations with management are the two most important work-role outputs, and having an exhausting job is the most important work-role input. (vi) Workers in Eastern European countries tend to value high income.
TL;DR: The average decline in sperm count was virtually unchanged from that reported previously by Carlsen et al. and that the observed trends previously reported for 1938-1990 are also seen in data from 1934-1996.
Abstract: In 1992 Carlsen et al. reported a significant global decline in sperm density between 1938 and 1990 [Evidence for Decreasing Quality of Semen during Last 50 Years. Br Med J 305:609-613 (1992)]. We subsequently published a reanalysis of the studies included by Carlsen et al. [Swan et al. Have Sperm Densities Declined? A Reanalysis of Global Trend Data. Environ Health Perspect 105:1228-1232 (1997)]. In that analysis we found significant declines in sperm density in the United States and Europe/Australia after controlling for abstinence time, age, percent of men with proven fertility, and specimen collection method. The declines in sperm density in the United States (approximately 1.5%/year) and Europe/Australia (approximately 3%/year) were somewhat greater than the average decline reported by Carlsen et al. (approximately 1%/year). However, we found no decline in sperm density in non-Western countries, for which data were very limited. In the current study, we used similar methods to analyze an expanded set of studies. We added 47 English language studies published in 1934-1996 to those we had analyzed previously. The average decline in sperm count was virtually unchanged from that reported previously by Carlsen et al. (slope = -0.94 vs. -0.93). The slopes in the three geographic groupings were also similar to those we reported earlier. In North America, the slope was somewhat less than the slope we had found for the United States (slope = -0.80; 95% confidence interval (CI), -1.37--0.24). Similarly, the decline in Europe (slope = -2.35; CI, -3.66--1.05) was somewhat less than reported previously. As before, studies from other countries showed no trend (slope = -0.21; CI, -2.30-1.88). These results are consistent with those of Carlsen et al. and our previous results, suggesting that the reported trends are not dependent on the particular studies included by Carlsen et al. and that the observed trends previously reported for 1938-1990 are also seen in data from 1934-1996.
TL;DR: The spin Hall effect in the presence of spin diffusion from a semiclassical Boltzmann equation is derived, and the magnitude of the spin Hall voltage due to the spin accumulation is found to be much larger than that of magnetic multilayers.
Abstract: Hirsch [Phys. Rev. Lett. 83, 1834 (1999)] recently proposed a spin Hall effect based on the anomalous scattering mechanism in the absence of spin-flip scattering. Since the anomalous scattering causes both anomalous currents and a finite spin-diffusion length, we derive the spin Hall effect in the presence of spin diffusion from a semiclassical Boltzmann equation. When the formulation is applied to certain metals and semiconductors, the magnitude of the spin Hall voltage due to the spin accumulation is found to be much larger than that of magnetic multilayers. An experiment is proposed to measure this spin Hall effect.
TL;DR: The children with variable achievement test performance did not differ from the academically normal children in any cognitive domain, whereas the children in the LD groups showed specific patterns of cognitive deficit, above and beyond the influence of IQ.
TL;DR: A comprehensive review of the literature of passive transfer in calves including factors that affect passive transfer status, testing modalities, effects of failure of Passive transfer on baseline mortality, consequences of failure, and some treatment options is presented.
Abstract: Passive transfer of colostral immunoglobulins has long been accepted as imperative to optimal calf health Many factors, including timing of colostrum ingestion, the method and volume of colostrum administration, the immunoglobulin concentration of the colostrum ingested, and the age of the dam have been implicated in affecting the optimization of absorption The practice of colostrum pooling, the breed and presence of the dam, and the presence of respiratory acidosis in the calf also may affect passive transfer Various tests have been reported to accurately measure passive transfer status in neonatal calves The radial immunodiffusion and the enzyme-linked immunosorbent assay (ELISA) are the only tests that directly measure serum IgG concentration All other available tests including serum total solids by refractometry, sodium sulfite turbidity test, zinc sulfate turbidity test, serum gamma-glutamyl transferase activity, and whole blood glutaraldehyde gelation estimate serum IgG concentration based on concentration of total globulins or other proteins whose passive transfer is statistically associated with that of IgG This paper presents a comprehensive review of the literature of passive transfer in calves including factors that affect passive transfer status, testing modalities, effects of failure of passive transfer on baseline mortality, consequences of failure of passive transfer, and some treatment options Many previously accepted truisms regarding passive transfer in calves should be rejected based on the results of recent research
TL;DR: Fecal glucocorticoid assays reliably detect endogenous changes in adrenal activity of a diverse array of species and, where comparisons were made, the ICN corticosterone antibody generally was superior to other antibodies for measuring glucoc Corticoid metabolites in feces.
TL;DR: A blueprint for exercise biology research in the new millennium is developed and it is proposed that exercise biologists do not study "the effect of physical activity" but in reality study the effect of reintroducing exercise into an unhealthy sedentary population that is genetically programmed to expect physical activity.
Abstract: In this review, we develop a blueprint for exercise biology research in the new millennium. The first part of our plan provides statistics to support the contention that there has been an epidemic emergence of modern chronic diseases in the latter part of the 20th century. The health care costs of these conditions were almost two-thirds of a trillion dollars and affected 90 million Americans in 1990. We estimate that these costs are now approaching $1 trillion and stand to further dramatically increase as the baby boom generation ages. We discuss the reaction of the biomedical establishment to this epidemic, which has primarily been to apply modern technologies to stabilize overt clinical problems (e.g., secondary and tertiary prevention). Because this approach has been largely unsuccessful in reversing the epidemic, we argue that more emphasis must be placed on novel approaches such as primary prevention, which requires attacking the environmental roots of these conditions. In this respect, a strong association exists between the increase in physical inactivity and the emergence of modern chronic diseases in 20th century industrialized societies. Approximately 250,000 deaths per year in the United States are premature due to physical inactivity. Epidemiological data have established that physical inactivity increases the incidence of at least 17 unhealthy conditions, almost all of which are chronic diseases or considered risk factors for chronic diseases. Therefore, as part of this review, we present the concept that the human genome evolved within an environment of high physical activity. Accordingly, we propose that exercise biologists do not study "the effect of physical activity" but in reality study the effect of reintroducing exercise into an unhealthy sedentary population that is genetically programmed to expect physical activity. On the basis of healthy gene function, exercise research should thus be viewed from a nontraditional perspective in that the "control" group should actually be taken from a physically active population and not from a sedentary population with its predisposition to modern chronic diseases. We provide exciting examples of exercise biology research that is elucidating the underlying mechanisms by which physical inactivity may predispose individuals to chronic disease conditions, such as mechanisms contributing to insulin resistance and decreased skeletal muscle lipoprotein lipase activity. Some findings have been surprising and remarkable in that novel signaling mechanisms have been discovered that vary with the type and level of physical activity/inactivity at multiple levels of gene expression. Because this area of research is underfunded despite its high impact, the final part of our blueprint for the next millennium calls for the National Institutes of Health (NIH) to establish a major initiative devoted to the study of the biology of the primary prevention of modern chronic diseases. We justify this in several ways, including the following estimate: if the percentage of all US morbidity and mortality statistics attributed to the combination of physical inactivity and inappropriate diet were applied as a percentage of the NIH's total operating budget, the resulting funds would equal the budgets of two full institutes at the NIH! Furthermore, the fiscal support of studies elucidating the scientific foundation(s) targeted by primary prevention strategies in other public health efforts has resulted in an increased efficacy of the overall prevention effort. We estimate that physical inactivity impacts 80-90% of the 24 integrated review group (IRG) topics proposed by the NIH's Panel on Scientific Boundaries for Review, which is currently directing a major restructuring of the NIH's scientific funding system. Unfortunately, the primary prevention of chronic disease and the investigation of physical activity/inactivity and/or exercise are not mentioned in the almost 200 total subtopics comprising t
TL;DR: The MacArthur Communicative Development Inventories (CDI) as mentioned in this paper are a pair of widely used parent-report instruments for assessing communicative skills in infants and toddlers, and they have been widely used in clinical applications.
Abstract: The MacArthur Communicative Development Inventories (CDIs) are a pair of widely used
parent-report instruments for assessing communicative skills in infants and toddlers. This report
describes short-form versions of the CDIs and their development, summarizes newly available
normative data and psychometric properties of the instruments, and discusses research and
clinical applications. The infant short form (Level I, for 8- to 18-month-olds) contains an
89-word checklist for vocabulary comprehension and production. The two parallel versions of
the toddler short form (Level II, Forms A and B, for 16- to 30-month-olds) each contain a
100-word vocabulary production checklist and a question about word combinations. The forms
may also be useful with developmentally delayed children beyond the specified age ranges.
Copies of the short forms and the normative tables appear in the appendices.
TL;DR: Cell wall damage followed by cytoplasmic membrane damage leading to a direct intracellular attack has been proposed as the sequence of events when microorganisms undergo TiO 2 photocatalytic attack.
Abstract: When exposed to near-UV light, titanium dioxide (TiO 2 ) exhibits a strong bactericidal activity. However, the killing mechanism(s) underlying the TiO 2 photocatalytic reaction is not yet well understood. The aim of the present study is to investigate the cellular damage sites and their contribution to cell death. A sensitive approach using o -nitrophenol β- d– galactopyranosideside (ONPG) as the probe and Escherichia coli as model cells has been developed. This approach is used to illustrate damages to both the cell envelope and intracellular components caused by TiO 2 photocatalytic reaction. Treatment of E. coli with TiO 2 and near-UV light resulted in an immediate increase in permeability to small molecules such as ONPG, and the leakage of large molecules such as β- d– galactosidase after 20 min. Kinetic data showed that cell wall damage took place in less than 20 min, followed by a progressive damage of cytoplasmic membrane and intracellular components. The results from the ONPG assay correlated well with the loss of cell viability. Cell wall damage followed by cytoplasmic membrane damage leading to a direct intracellular attack has therefore been proposed as the sequence of events when microorganisms undergo TiO 2 photocatalytic attack. It has been found that smaller TiO 2 particles cause quicker intracellular damage. Evidence has been obtained that indicated that the TiO 2 photocatalytic reaction results in continued bactericidal activity after the UV illumination terminates.
TL;DR: Results revealed strong support for the motivational model, indicating that broad traits related to neuroticism and extraversion promote involvement in alcohol use and risky sex via distinct pathways and provides a highly general though not complete account of risky behaviors.
Abstract: The present study tested a motivational model in which personality influences on risky behaviors were hypothesized to be primarily indirectly mediated, by shaping the nature and quality of emotional experience as well as characteristic styles of coping with these emotions. This model was tested in a representative community sample of 1,666 young adults, aged 18 to 25 years old. Results revealed strong support for the model, indicating that broad traits related to neuroticism and extraversion promote involvement in alcohol use and risky sex via distinct pathways. Neurotic individuals were prone to engage in risky behaviors as a way to cope with aversive mood states, whereas extraverted individuals were more likely to engage in risky behaviors as a way to enhance positive affective experience. In contrast, impulsivity directly predicted some forms of risk taking, and interacted with extraversion and neuroticism to predict motives for risky behaviors. The model provides a highly general though not complete account of risky behaviors.
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TL;DR: This paper provides a general choice-based framework for modeling such interactions which subsumes a number of specific models which have been studied and illustrates the relationship between interactions-based models and models in statistical mechanics.
Abstract: This paper describes a range of methods which have been proposed to study interactions in economic and social contexts. By interactions, we refer to interdependences between individual decisions which are not mediated by markets. These types of models have been employed to understand phenomena ranging from the effect of neighborhoods on the life prospects of children to the evolution of political party platforms. We provide a general choice-based framework for modeling such interactions which subsumes a number of specific models which have been studied. This framework illustrates the relationship between interactions-based models and models in statistical mechanics. Our analysis is then extended to the econometrics of these models, with an emphasis on the identification of group-level influences on individual behavior. Finally, we review some of the empirical work on interactions which has appeared in the social science literature.
TL;DR: The authors evaluated the extent to which 14 research skills were enhanced by science undergraduates' participation in an undergraduate research experience (URE) Fifty-seven undergraduates self-rated their ability to perform the skills at the beginning and end of the URE Faculty mentors' ratings of their respective interns' skills served as an objective measure of intern skill level.
Abstract: This study evaluated the extent to which 14 research skills were enhanced by science undergraduates' participation in an undergraduate research experience (URE) Fifty-seven undergraduates self-rated their ability to perform the skills at the beginning and end of the URE Faculty mentors' ratings of their respective interns' skills served as an objective measure of intern skill level Mentor and intern data revealed that the URE enhanced some skills better than others At the end of the URE, female interns rated their ability to understand concepts in their field significantly lower than did male interns Female interns also tended to perceive less of an increase in their ability to formulate research hypotheses than did male interns
TL;DR: In this paper, a study of 25 pioneering companies whose success has been based on radical business innovation indicates that such companies are better described as market driving while market driven processes are excellent in generating incremental innovation, they rarely produce the type of radical innovation which underlies market driving companies.
TL;DR: The empirical literature on the comorbidity between borderline personality disorder (BPD) and substance use disorders (SUDs) is reviewed and the conceptualization of the relations and interactions of the major factors influencing the development of BPD and contributing to the comorosity between B PD and SUDs is presented.
TL;DR: In this article, the authors examined audit fees of Big 6 and non-Big 6 accounting firms for 348 publicly listed Hong Kong companies and found that Big 6 premiums for both general brand name and for industry specialization led to lower fees for a clientele seeking low-priced audits.
Abstract: Audit fees of Big 6 and non‐Big 6 accounting firms are examined for 348 publicly listed Hong Kong companies. Using more recent data than prior studies, we find evidence of Big 6 premiums for both general brand name and for industry specialization. In addition, we find that the large local firm Kwan Wong Tan & Fong, which is the market leader in the property sector, has significantly lower fees than both Big 6 and other non‐Big 6 auditors in that industry. Specialization thus leads to different results for Big 6 and non‐Big 6 firms and suggests a market segment not previously identified: non‐Big 6 specialization, which leads to production economies and the capture of market share through lower fees for a clientele seeking low‐priced audits. These results also suggest that prior studies do not recognize sufficiently that Big 6 brand‐name reputation is a necessary foundation on which to achieve higher priced quality‐differentiated audits based on industry specialization.
TL;DR: In this paper, p-type ZnO was obtained by arsenic doping using pulsed laser ablation and Acceptor concentrations of As atoms were in the range from high 10 17 to high 10 21 ǫ atoms/cm 3 as determined by secondary ion mass spectroscopy (SIMS) and Hall effect measurements.
TL;DR: In this paper, a linear optimal control based on LQR control is proposed for static compensators, which is shown to be superior in terms of response profile and control effort required.
Abstract: A static compensator (STATCOM) is a device that can provide reactive support to a bus. It consists of voltage sourced converters connected to an energy storage device on one side and to the power system on the other. In this paper the conventional method of PI control is compared and contrasted with various feedback control strategies. A linear optimal control based on LQR control is shown to be superior in terms of response profile and control effort required. These methodologies are applied to an example power system.
TL;DR: In this paper, spin-coated specimens of crosslinked polydimethylsiloxane (PDMS) exposed to radio-frequency (RF) and microwave (MW) oxygen plasma were studied by specular neutron reflectometry, X-ray photoelectron spectroscopy (XPS), Wilhelmy balance, contact angle measurements, scanning electron microscopy and atomic force microscopy.
TL;DR: The Funnel Technique provides a straightforward, direct, and inexpensive way to very safely apply pedicle screws in the cervical, thoracic, or lumbar spine.
Abstract: Pedicle screws have dramatically improved the outcomes of spinal reconstruction requiring spinal fusion. Short-segment surgical treatments based on the use of pedicle screws for the treatment of neoplastic, developmental, congenital, traumatic, and degenerative conditions have been proved to be practical, safe, and effective. The Funnel Technique provides a straightforward, direct, and inexpensive way to very safely apply pedicle screws in the cervical, thoracic, or lumbar spine. Carefully applied pedicle-screw fixation does not produce severe or frequent complications. Pedicle-screw fixation can be effectively and safely used wherever a vertebral pedicle can accommodate a pedicle screw--that is, in the cervical, thoracic, or lumbar spine. Training in pedicle-screw application should be standard in orthopaedic training programs since pedicle-screw fixation represents the so-called gold standard of spinal internal fixation.