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Showing papers by "University of South Carolina published in 2001"


Journal ArticleDOI
TL;DR: Gold nanorods with aspect ratios of 4.6 ± 1.2, 13 ± 2, and 18 ± 2.5 are prepared by a seeding growth approach in the presence of an aqueous miceller template.
Abstract: Gold nanorods with aspect ratios of 4.6 ± 1.2, 13 ± 2, and 18 ± 2.5 (all with 16 ± 3 nm short axis) are prepared by a seeding growth approach in the presence of an aqueous miceller template. Citrate-capped 3.5 nm diameter gold particles, prepared by the reduction of HAuCl4 with borohydride, are used as the seed. The aspect ratio of the nanorods is controlled by varying the ratio of seed to metal salt. The long rods are isolated from spherical particles by centrifugation.

2,428 citations


Journal ArticleDOI
TL;DR: In this article, the authors suggest that organizational members can develop feelings of ownership toward the organization and various organizational factors under certain conditions, and identify its roots and the primary routes through which it develops.
Abstract: Building upon the observation that individuals feel ownership toward a variety of targets, we suggest that under certain conditions, organizational members can develop feelings of ownership toward the organization and various organizational factors. We define psychological ownership, identify its “roots” and the primary “routes” through which it develops, and propose certain organizational outcomes. We discuss the conceptual distinctiveness of psychological ownership from a set of related constructs and suggest some theoretical and managerial implications of our theory.

1,651 citations


Journal ArticleDOI
TL;DR: In this article, the authors estimate the time it takes for the polymer melt to fill up the void space between the mold and the polymer film, such that the time is given by t ˆ 2 z 2 2
Abstract: the cross-sectional SEM image, the contact angle is estimated to be about 85 . When we insert into Equation 1 the surface tension (~30 dyne/cm) and density (0.95 g/cm) of SBS and L of 300 nm, a maximum height of 1.87 m is obtained, which indicates that the height of the patterned polymer can be made quite large. In fact, we were able to fabricate polymer structures with a step height as high as 5 lm for an 80 lm line-and-space pattern. If we take into account the interaction at the polymer/substrate interface and the solid-like properties of the polymer melt, the theoretical maximum height would be reduced. For a more accurate model, further study would be required. The time it takes for the polymer melt to fill up the void space between the mold and the polymer film can be estimated. If we neglect the effect of gravity, then the surface tension and viscosity of the polymer melt and the size of the capillary determine the rate of flow such that the time is given by t ˆ 2 z 2

1,626 citations


Journal ArticleDOI
02 Oct 2001-Langmuir
TL;DR: In this paper, gold nanoparticles of diameters 5−40 nm were prepared with 10−15% standard deviation in diameter from 3.5 ± 0.7 nm gold particle seeds.
Abstract: Following a seeding growth approach, gold nanoparticles of diameters 5−40 nm were prepared with 10−15% standard deviation in diameter from 3.5 ± 0.7 nm gold particle seeds. Particle size can be controlled by varying the ratio of seed to metal salt, and thus any size in the range 5−40 nm can be prepared. The method can also be scaled up to produce 10−100 mg of gold nanoparticles.

1,310 citations


Journal ArticleDOI
TL;DR: A trait measure of consumers' need for uniqueness is developed and validated as an individual's pursuit of differentness relative to others that is achieved through the acquisition, utilization, and disposition of consumer goods for the purpose of developing and enhancing one's personal and social identity.
Abstract: Consumers acquire and display material possessions for the purpose of feeling differentiated from other people and, thus, are targeted with a variety of marketing stimuli that attempt to enhance self‐perceptions of uniqueness. Because the pursuit of differentness (or counterconformity motivation) varies across individuals to influence consumer responses, we develop and validate a trait measure of consumers’ need for uniqueness. Consumers' need for uniqueness is defined as an individual’s pursuit of differentness relative to others that is achieved through the acquisition, utilization, and disposition of consumer goods for the purpose of developing and enhancing one’s personal and social identity. Following assessments of the scale’s latent structure, a series of validation studies examines the scale’s validity. The presentation of empirical work is followed by a discussion of how consumers' need for uniqueness could be used in better understanding consumer behavior and the role consumption plays in people...

1,288 citations


Journal ArticleDOI
TL;DR: Using a seed-mediated growth approach in a rod-like micellar media, silver nanorods of varied aspect ratio were prepared from nearly spherical 4 nm silver nanoparticles as mentioned in this paper.

1,127 citations


Journal ArticleDOI
TL;DR: The strengths and limitations of the methods used to evaluate physical activity in children and adolescents are summarized and future investigations of physical activity instruments should validate the novel instrument against a higher standard.
Abstract: Chronic disease risk factors, including a sedentary lifestyle, may be present even in young children, suggesting that early prevention programmes may be critical to reducing the rates of chronic disease. Accurate assessment of physical activity in children is necessary to identify current levels of activity and to assess the effectiveness of intervention programmes designed to increase physical activity. This article summarises the strengths and limitations of the methods used to evaluate physical activity in children and adolescents. MEDLINE searches and journal article citations were used to locate 59 articles that validated physical activity measurement methods in children and adolescents. Only those methods that were validated against a more stringent measure were included in the review. Based on the definition of physical activity as any bodily movement resulting in energy expenditure (EE), direct observation of the individual's movement should be used as the gold standard for physical activity research. The doubly labelled water technique and indirect calorimetry can also be considered criterion measures for physical activity research, because they measure EE, a physiologic consequence closely associated with physical activity. Devices such as heart rate monitors, pedometers and accelerometers have become increasingly popular as measurement tools for physical activity. These devices reduce the subjectivity inherent in survey methods and can be used with large groups of individuals. Heart rate monitoring is sufficiently valid to use in creating broad physical activity categories (e.g. highly active, somewhat active, sedentary) but lacks the specificity needed to estimate physical activity in individuals. Laboratory and field validations of pedometers and accelerometers yield relatively high correlations using oxygen consumption (r = 0.62 to 0.93) or direct observation (r = 0.80 to 0.97) as criterion measures, although, they may not be able to capture all physical activity. Physical activity has traditionally been measured with surveys and recall instruments. These techniques must be used cautiously in a paediatric population that has difficulty recalling such information. Still, some studies have reported 73.4% to 86.3% agreement between these instruments and direct observation. Future investigations of physical activity instruments should validate the novel instrument against a higher standard. Additional studies are needed to investigate the possibility of improving the accuracy of measurement by combining 2 or more techniques. The accurate measurement of physical activity is critical for determining current levels of physical activity, monitoring compliance with physical activity guidelines, understanding the dose-response relationship between physical activity and health and determining the effectiveness of intervention programmes designed to improve physical activity.

1,106 citations


Journal ArticleDOI
TL;DR: In this article, the authors compared the physical activity (PA) patterns and the hypothesized psychosocial and environmental determinants of PA in an ethnically diverse sample of obese and non-obese middle school children.
Abstract: OBJECTIVE: To compare the physical activity (PA) patterns and the hypothesized psychosocial and environmental determinants of PA in an ethnically diverse sample of obese and non-obese middle school children. DESIGN: Cross-sectional study. SUBJECTS: One-hundred and thirty-three non-obese and 54 obese sixth grade children (mean age of 11.4±0.6). Obesity status determined using the age-, race- and gender-specific 95th percentile for BMI from NHANES-1. MEASUREMENTS: Objective measurements were collected of PA over a 7-day period using the CSA 7164 accelerometer: total daily counts; daily moderate (3–5.9 METs) physical activity (MPA); daily vigorous physical activity (≥6 METs; VPA); and weekly number of 5, 10 and 20 min bouts of moderate-to-vigorous physical activity (≥3 METs, MVPA). Self-report measures were collected of PA self-efficacy; social influences regarding PA, beliefs about PA outcomes; perceived PA levels of parents and peers, access to sporting and/or fitness equipment at home, involvement in community-based PA organizations; participation in community sports teams; and hours spent watching television or playing video games. RESULTS: Compared to their non-obese counterparts, obese children exhibited significantly lower daily accumulations of total counts, MPA and VPA as well as significantly fewer 5, 10 and 20 min bouts of MVPA. Obese children reported significantly lower levels of PA self-efficacy, were involved in significantly fewer community organizations promoting PA and were significantly less likely to report their father or male guardian as physically active. CONCLUSIONS: The results are consistent with the hypothesis that physical inactivity is an important contributing factor in the maintenance of childhood obesity. Interventions to promote PA in obese children should endeavor to boost self-efficacy perceptions regarding exercise, increase awareness of, and access to, community PA outlets, and increase parental modeling of PA.

760 citations


Journal ArticleDOI
TL;DR: Findings show that measures of body fat are strongly associated with circulating levels of CRP and fibrinogen, and chronic, subclinical inflammation may be one pathophysiological mechanism explaining the increased risk of atherosclerotic disease associated with adiposity.
Abstract: OBJECTIVE: To study the relation of fibrinogen and C-reactive protein (CRP) to various measures of body fat and body fat distribution and to investigate whether these relations were explained by differences in insulin sensitivity. DESIGN AND SUBJECTS: Cross-sectional analysis of the IRAS (Insulin Resistance Atherosclerosis Study), a large (n=1559) tri-ethnic population (non-Hispanic whites, African-Americans and Mexican-Americans) across different states of glucose tolerance. MEASUREMENTS: Glucose tolerance (oral glucose tolerance test), insulin sensitivity (frequently sampled intravenous glucose tolerance test and minimal model analysis), assessment of body fat mass and distribution (weight, girths, bioelectrical impedance), subclinical atherosclerosis (B-mode ultrasonography of carotid artery intima-media thickness, IMT), CRP (highly sensitive immunoassay), fibrinogen (standard assay). RESULTS: Both CRP and fibrinogen were related to all measures of body fat. Strong correlations (correlation coefficient r≥0.35) were found between CRP and body mass index (BMI), waist circumference and adipose body mass, respectively. The associations were consistent in non-diabetic and type-2 diabetic subjects, were generally stronger in women, and were only moderately attenuated by the prevailing insulin sensitivity (SI). In a multivariate linear regression model waist circumference explained 14.5% of the variability of circulating CRP levels (P=0.0001), BMI 0.4% (P=0.0067), and SI 1.7% (P=0.0001). Common carotid artery IMT was related to CRP and fibrinogen in men, but not in women, and was attenuated after adjusting for BMI or waist. CONCLUSION: Our findings show that measures of body fat are strongly associated with circulating levels of CRP and fibrinogen. These associations were not explained by lower SI in obese subjects. Chronic, subclinical inflammation may be one pathophysiological mechanism explaining the increased risk of atherosclerotic disease associated with adiposity.

698 citations


Journal ArticleDOI
TL;DR: In this paper, the authors examined the seed-mediated growth of gold nanoparticles by transmission electron microscopy and electronic absorption spectroscopy and found that changing the seed concentration does affect the size of the product nanoparticles, but the method of reagent addition drastically affects the outcome even more.
Abstract: Central to the concept of seed-mediated growth of nanoparticles is that small nanoparticle seeds serve as nucleation centers to grow nanoparticles to a desired size. We have examined this common assumption in a model system, the wet chemical synthesis of gold nanoparticles via reduction of a gold salt, by transmission electron microscopy and electronic absorption spectroscopy. We find that changing the seed concentration does affect the size of the product nanoparticles, but the method of reagent addition drastically affects the outcome even more. For fast addition of reducing agent, the presence of seeds appears to promote the formation of more seeds instead of growth. The observed nucleations are drastically enhanced (99%) compared to particle growth. For slow addition of reducing agent, the seeds do grow, but the product nanoparticle's degree of homogeneity in shape is compromised. For higher concentrations of seeds, nanoparticle growth is better controlled for slow addition of reducing agent compared ...

649 citations


Journal ArticleDOI
04 May 2001-Science
TL;DR: Results suggest that microbial processes alter the molecular structure of DOM, making it resistant to further degradation and thereby preserving fixed carbon in the ocean.
Abstract: Most of the oceanic reservoir of dissolved organic matter (DOM) is of marine origin and is resistant to microbial oxidation, but little is known about the mechanisms of its formation. In a laboratory study, natural assemblages of marine bacteria rapidly (in <48 hours) utilized labile compounds (glucose, glutamate) and produced refractory DOM that persisted for more than a year. Only 10 to 15% of the bacterially derived DOM was identified as hydrolyzable amino acids and sugars, a feature consistent with marine DOM. These results suggest that microbial processes alter the molecular structure of DOM, making it resistant to further degradation and thereby preserving fixed carbon in the ocean.

Journal ArticleDOI
22 Jun 2001-Science
TL;DR: The emerging view is that RNA silencing is part of a sophisticated network of interconnected pathways for cellular defense, RNA surveillance, and development and that it may become a powerful tool to manipulate gene expression experimentally.
Abstract: RNA silencing is a remarkable type of gene regulation based on sequence-specific targeting and degradation of RNA. The term encompasses related pathways found in a broad range of eukaryotic organisms, including fungi, plants, and animals. In plants, it serves as an antiviral defense, and many plant viruses encode suppressors of silencing. The emerging view is that RNA silencing is part of a sophisticated network of interconnected pathways for cellular defense, RNA surveillance, and development and that it may become a powerful tool to manipulate gene expression experimentally.

Journal ArticleDOI
TL;DR: For most individuals, the positive effects of regular exercise are exerted on blood lipids at low training volumes and accrue so that noticeable differences frequently occur with weekly energy expenditures of 1200 to 2200 kcal/wk, it appears that weekly exercise caloric expenditures that meet or exceed the higher end of this range are more likely to produce the desired lipid changes.
Abstract: Dose-response relationships between exercise training volume and blood lipid changes suggest that exercise can favourably alter blood lipids at low training volumes, although the effects may not be observable until certain exercise thresholds are met. The thresholds established from cross-sectional literature occur at training volumes of 24 to 32 km (15 to 20 miles) per week of brisk walking or jogging and elicit between 1200 to 2200 kcal/wk. This range of weekly energy expenditure is associated with 2 to 3 mg/dl increases in high-density lipoprotein-cholesterol (HDL-C) and triglyceride (TG) reductions of 8 to 20 mg/dl. Evidence from cross-sectional studies indicates that greater changes in HDL-C levels can be expected with additional increases in exercise training volume. HDL-C and TG changes are often observed after training regimens requiring energy expenditures similar to those characterised from cross-sectional data. Training programmes that elicit 1200 to 2200 kcal/wk in exercise are often effective at elevating HDL-C levels from 2 to 8 mg/dl, and lowering TG levels by 5 to 38 mg/dl. Exercise training seldom alters total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C). However, this range of weekly exercise energy expenditure is also associated with TC and LDL-C reductions when they are reported. The frequency and extent to which most of these lipid changes are reported are similar in both genders, with the exception of TG. Thus, for most individuals, the positive effects of regular exercise are exerted on blood lipids at low training volumes and accrue so that noticeable differences frequently occur with weekly energy expenditures of 1200 to 2200 kcal/wk. It appears that weekly exercise caloric expenditures that meet or exceed the higher end of this range are more likely to produce the desired lipid changes. This amount of physical activity, performed at moderate intensities, is reasonable and attainable for most individuals and is within the American College of Sports Medicine's currently recommended range for healthy adults.

Journal ArticleDOI
TL;DR: Recommendations for using electronic pedometers to objectively quantify physical activity (specifically ambulatory activity) for research and surveillance as well as clinical and program applications are suggested.
Abstract: Researchers and practitioners require guidelines for using electronic pedometers to objectively quantify physical activity (specifically ambulatory activity) for research and surveillance as well as clinical and program applications. Methodological considerations include choice of metric and length of monitoring frame as well as different data recording and collection procedures. A systematic review of 32 empirical studies suggests we can expect 12,000–16,000 steps/day for 8–10-year-old children (lower for girls than boys); 7,000–13,000 steps/day for relatively healthy, younger adults (lower for women than men); 6,000–8,500 steps/day for healthy older adults; and 3,500–5,500 steps/day for individuals living with disabilities and chronic illnesses. These preliminary recommendations should be modified and refined, as evidence and experience using pedometers accumulates.

Journal ArticleDOI
TL;DR: C. crescentus is, to the authors' knowledge, the first free-living α-class proteobacterium to be sequenced and will serve as a foundation for exploring the biology of this group of bacteria, which includes the obligate endosymbiont and human pathogen Rickettsia prowazekii, the plant pathogen Agrobacterium tumefaciens, and the bovine andhuman pathogen Brucella abortus.
Abstract: The complete genome sequence of Caulobacter crescentus was determined to be 4,016,942 base pairs in a single circular chromosome encoding 3,767 genes. This organism, which grows in a dilute aquatic environment, coordinates the cell division cycle and multiple cell differentiation events. With the annotated genome sequence, a full description of the genetic network that controls bacterial differentiation, cell growth, and cell cycle progression is within reach. Two-component signal transduction proteins are known to play a significant role in cell cycle progression. Genome analysis revealed that the C. crescentus genome encodes a significantly higher number of these signaling proteins (105) than any bacterial genome sequenced thus far. Another regulatory mechanism involved in cell cycle progression is DNA methylation. The occurrence of the recognition sequence for an essential DNA methylating enzyme that is required for cell cycle regulation is severely limited and shows a bias to intergenic regions. The genome contains multiple clusters of genes encoding proteins essential for survival in a nutrient poor habitat. Included are those involved in chemotaxis, outer membrane channel function, degradation of aromatic ring compounds, and the breakdown of plant-derived carbon sources, in addition to many extracytoplasmic function sigma factors, providing the organism with the ability to respond to a wide range of environmental fluctuations. C. crescentus is, to our knowledge, the first free-living alpha-class proteobacterium to be sequenced and will serve as a foundation for exploring the biology of this group of bacteria, which includes the obligate endosymbiont and human pathogen Rickettsia prowazekii, the plant pathogen Agrobacterium tumefaciens, and the bovine and human pathogen Brucella abortus.

Journal ArticleDOI
TL;DR: The findings suggest the COSMED K4 b2 portable metabolic measurement system is acceptable for measuring oxygen uptake over a fairly wide range of exercise intensities.
Abstract: The purpose of this investigation was to assess the accuracy of the COSMED K4 b2 portable metabolic measurement system against the criterion Douglas bag (DB) method. During cycle ergometry on consecutive days, oxygen consumption (VO2), carbon dioxide production (VCO2), minute ventilation (VE), and respiratory exchange ratio (R) were measured at rest and during power outputs of 50, 100, 150, 200, and 250W. No significant differences (P > 0.05) were observed in VO2 between the K4 b2 and DB at rest and at 250W. Though the K4 b2 values were significantly higher (P<0.05) than DB values at 50, 100, 150, and 200 W, the magnitude of these differences was small (0.088, 0.092, 0.096, and 0.088 L x min(-1), respectively). VCO2 and VE values from the K4 b2 were significantly lower than the DB at 200 and 250 W, while no significant differences were observed from rest through 150W. The slight overestimation of VO2 (50-200 W) combined with the underestimation of VCO2 (200 and 250W) by the K4 b2 resulted in significantly lower R values at every stage. These findings suggest the COSMED K4 b2 portable metabolic measurement system is acceptable for measuring oxygen uptake over a fairly wide range of exercise intensities.

Journal ArticleDOI
TL;DR: Evidence of factorial validity and convergent evidence for construct validity indicate that the PACES is a valid measure of physical activity enjoyment among adolescent girls, suitable for use as a mediator variable in interventions designed to increase physical activity.

Journal ArticleDOI
TL;DR: It is demonstrated that spatial and temporal variability in thermal stress can be highly complex, and “snapshot” sampling of temperature and biochemical indices may not always be a reliable method for defining thermal stress at a site.
Abstract: Thermal stress has been considered to be among the most important determinants of organismal dis- tribution in the rocky intertidal zone. Yet our understanding of how body temperatures experienced under field condi- tions vary in space and time, and of how these temperatures translate into physiological performance, is still rudimen- tary. We continuously monitored temperatures at a site in central California for a period of two years, using loggers designed to mimic the thermal characteristics of mussels, Mytilus californianus. Model mussel temperatures were re- corded on both a horizontal and a vertical, north-facing microsite, and in an adjacent tidepool. We periodically measured levels of heat shock proteins (Hsp70), a measure of thermal stress, from mussels at each microsite. Mussel temperatures were consistently higher on the horizontal surface than on the vertical surface, and differences in body temperature between these sites were reflected in the amount of Hsp70. Seasonal peaks in extreme high temper- atures ("acute" high temperatures) did not always coincide with peaks in average daily maxima ("chronic" high tem- peratures), suggesting that the time history of body temper- ature may be an important factor in determining levels of thermal stress. Temporal patterns in body temperature dur- ing low tide were decoupled from patterns in water temper- ature, suggesting that water temperature is an ineffective metric of thermal stress for intertidal organisms. This study demonstrates that spatial and temporal variability in thermal stress can be highly complex, and "snapshot" sampling of temperature and biochemical indices may not always be a reliable method for defining thermal stress at a site.

Journal ArticleDOI
TL;DR: The main result of the paper is the construction of an adaptive scheme which produces an approximation to u with error O(N -s ) in the energy norm, whenever such a rate is possible by N-term approximation.
Abstract: This paper is concerned with the construction and analysis of wavelet-based adaptive algorithms for the numerical solution of elliptic equations. These algorithms approximate the solution u of the equation by a linear combination of N wavelets, Therefore, a benchmark for their performance is provided by the rate of best approximation to u by an arbitrary linear combination of N wavelets (so called N-term approximation), which would be obtained by keeping the N largest wavelet coefficients of the real solution (which of course is unknown). The main result of the paper is the construction of an adaptive scheme which produces an approximation to u with error O(N -s ) in the energy norm, whenever such a rate is possible by N-term approximation. The range of s > 0 for which this holds is only limited by the approximation properties of the wavelets together with their ability to compress the elliptic operator. Moreover, it is shown that the number of arithmetic operations needed to compute the approximate solution stays proportional to N. The adaptive algorithm applies to a wide class of elliptic problems and wavelet bases. The analysis in this paper puts forward new techniques for treating elliptic problems as well as the linear systems of equations that arise from the wavelet discretization.

Journal ArticleDOI
TL;DR: The ability of the LF isotherm to model MIPs suggests that a unimodal heterogeneous distribution is an accurate approximation of the distribution found in homogeneous and heterogeneous MIPS.
Abstract: The majority of binding models that have been applied to molecularly imprinted polymers (MIPs) have been homogeneous models. MIPs, on the other hand, are heterogeneous materials containing binding sites with a wide array of binding affinities and selectivities. Demonstrated is that the binding behavior of MIPs can be accurately modeled by the heterogeneous Langmuir-Freundlich (LF) isotherm. The applicability of the LF isotherm to MIPs was demonstrated using five representative MIPs from the literature, including both homogeneous and heterogeneous MIPs. Previously, such comparisons required the use of several different binding models and analyses, including the Langmuir model, the Freundlich model, and numerical approximation techniques. In contrast, the LF model enabled direct comparisons of the binding characteristics of MIPs that have very different underlying distributions and were measured under different conditions. The binding parameters can be calculated directly using the LF fitting coefficients that yield a measure of the total number of binding sites, mean binding affinity, and heterogeneity. Alternatively, solution of the Langmuir adsorption integral for the LF model enabled direct calculation of the corresponding affinity spectrum from the LF fitting coefficients from a simple algebraic expression, yielding a measure of the number of binding sites with respect to association constant Finally, the ability of the LF isotherm to model MIPs suggests that a unimodal heterogeneous distribution is an accurate approximation of the distribution found in homogeneous and heterogeneous MIPs.

Journal ArticleDOI
TL;DR: Positive excess return for smaller firms shows that smaller firms can leverage the lower price/performance ratio of new IT and reap greater rewards from IT investments than larger firms.
Abstract: Evaluating the effectiveness of Information Technology (IT) investments has always been an elusive but important goal of IS researchers. This study builds on a prior study that examined changes in the market value of the firm as reflected by the stock price in response to IT investment announcements. Data on stock prices were analyzed for 238 publicly traded companies. In addition to the stock price analysis, reaction of trading volume to the announcements was also examined to identify whether IT investment announcements affect investors' beliefs about IT value. Potentially confounding factors such as industry, size, and time lag effects were also analyzed. Size and time lag effects were found for all IT investment announcements. Reactions of price and volume were negatively related to firm size and became more positive over time. The positive excess return for smaller firms shows that smaller firms can leverage the lower price/performance ratio of new IT and reap greater rewards from IT investments than larger firms. Also, the result of time lag effect demonstrates that the stock market has recently begun to identify both tangible and intangible benefits of IT investments. For recent IT investment announcements, industry classification and firm size also affected the reactions of stock price to the announcements. This study provides optimism on the stock market reaction to IT investment announcements as well as further insight into the study of IT impacts on organizational performance.

Journal ArticleDOI
TL;DR: Path analysis showed that students' midterm scores and enrollment intentions at T1 were better predicted by the task-value factor, however, the typically stronger links of self-efficacy to performance and of task value to intentions were observed with T2 variables.

Journal ArticleDOI
TL;DR: A consistent sequence of events during their formation and evolution that suggests that they form in response to processes that are common to all such ophiolites has been found in this article.
Abstract: [1] Suprasubduction zone (SSZ) ophiolites display a consistent sequence of events during their formation and evolution that suggests that they form in response to processes that are common to all such ophiolites. This sequence includes the following: (1) birth, which entails the formation of the ophiolite above a nascent or reconfigured subduction zone; this stage is typically characterized by the eruption of arc tholeiite lavas and the formation of layered gabbros and sheeted dike complex; (2) youth, during which is continued melting of refractory asthenosphere (depleted during birth) occurs in response to fluid flux from the subducting slab, with extensional deformation of the older plutonic suite, eruption of refractory lavas, and the intrusion of wehrlite-pyroxenite; (3) maturity, with the onset of semistable arc volcanism, typically calc-alkaline, as the subduction zone matures and stabilizes, and the intrusion of quartz diorite and eruption of silicic lavas; and (4) death, which is the sudden demise of active spreading and ophiolite-related volcanism, which in many cases is linked to collision with an active spreading center and the onset of shallow underthrusting of the buoyant spreading axis; expressed as dikes and lavas with oceanic basalt compositions that crosscut or overlie rocks of the older suites; (5) resurrection, with emplacement by obduction onto a passive margin or accretionary uplift with continued subduction. The early stages (1–3) may be diachronous, and each stage may overlap in both time and space. The existence of this consistent progression implies that ophiolite formation is not a stochastic event but is a natural consequence of the SSZ tectonic setting.

Journal ArticleDOI
TL;DR: The DONUT experiment has analyzed 203 neutrino interactions recorded in nuclear emulsion targets as discussed by the authors, with an estimated background of 0.34 events, consistent with the Standard Model expectation.

Journal ArticleDOI
TL;DR: In this article, a numerical model was developed to predict the mass flow between channels in a polymer electrolyte membrane (PEM) fuel cell with a serpentine flow path, and the results indicated that flow distribution in both anode and cathode channels are significantly affected by the mass consumption patterns on the Membrane Electrode Assembly (MEA).

Journal ArticleDOI
TL;DR: The authors explored how a global firm's ability to foster successful relationships between its foreign subsidiaries' and headquarters' marketing operations can enhance the performance of products across markets, and found that cooperative behaviors are positively associated with product performance in the subsidiaries' markets.
Abstract: The authors explore how a global firm’s ability to foster successful relationships between its foreign subsidiaries’ and headquarters’ marketing operations can enhance the performance of products across markets. The results show that cooperative behaviors are positively associated with product performance in the subsidiaries’ markets. National culture in the foreign markets is also found to moderate the effect of trust on relational behaviors. In addition, the subsidiaries’ acquiescence becomes increasingly important as the firm attempts to standardize marketing programs.

Journal ArticleDOI
TL;DR: In this article, the authors present a theory of heterogeneous attribution, in which an individual's ability to make causal associations depends on his level of political sophistication, and argue that political sophistication dramatically influences the relative importance of personal and national economic judgments in shaping presidential candidate preference.
Abstract: This article presents a theory of heterogeneous attribution, in which an individual's ability to make causal associations depends on his level of political sophistication. Specifically, we maintain that political sophistication dramatically influences the relative importance of personal and national economic judgments in shaping presidential candidate preference. Pocketbook voting, we argue, should be common only among relatively sophisticated voters, who are able to make the associative linkage between changes in their personal financial status and governmental policy. Additionally, we hypothesize that sociotropic evaluations should be most influential for less sophisticated voters. Low sophisticates, we argue, will tend to assume that the national economy is entirely in the President's hands (and vote accordingly), whereas more sophisticated voters understand that the economy is affected by many actors and conditions that are largely beyond the President's control. Testing our theory using data from 1992, 1996, and 1998, we find strong support for our hypotheses. T here is little doubt that changing economic conditions profoundly influence voters' electoral decisions. Since the work of Kramer (1971), a large body of research has accumulated indicating that electoral results at both the state and national levels are driven at least partly by economic fluctuations (Tufte 1975; Hibbs, Rivers, and Vasilatos 1982; Chappell and Keech 1988). There is, however, less consensus on how individual voters, many of whom "have only the fuzziest of notions about many aspects of politics and government," (Markus 1988, 137), evaluate the economic information they receive and connect it to the political world. Do voters assess political candidates based on their personal economic well being (the "pocketbook" voting hypothesis), or on the perceived health of the national economy (the "sociotropic" voting hypothesis)? The answer depends centrally on how voters attribute causal responsibility for changes in both personal and national economic conditions, a process that, we argue, is strongly influenced by the voter's level of political sophistication. In this research, we explicitly incorporate political sophistication into the model of economic voting. For years, researchers have debated the degree of sophistication that voters bring to bear when making politically relevant evaluations (Suzuki 1991; Mackuen, Erikson, and Stimson 1992). At the macro-level, the debate has hinged largely on the difference between voter evaluations based on retrospective assessments and those guided by more "sophisticated" prospective economic forecasts. This dichotomy is typified by Mackuen, Erikson, and Stimson's (1992) distinction between retrospective voters, or cognitive "peasants," and prospective voters, or cognitive "bankers." Micro-level theorists have also noted the importance of

Journal ArticleDOI
TL;DR: hs-CRP has a degree of measurement stability that is similar to that of total cholesterol, and this relationship was not altered by the use of log-transformed hs- CRP data.
Abstract: Background: Increased concentrations of high-sensitivity C-reactive protein (hs-CRP), a marker of systemic inflammation, are associated with increased risk for coronary heart disease. Because of its relationship to inflammation, hs-CRP has considerable biologic variation. This study was carried out to characterize CRP variation and to compare it to another risk factor, total serum cholesterol. Methods: One hundred thirteen individuals were scheduled to have five measurements each of hs-CRP and total cholesterol carried out at quarterly intervals over a 1-year period. Variations of hs-CRP and total cholesterol were characterized, and classification accuracy was described and compared for both. Results: The relative variation was comparable for hs-CRP and total cholesterol. When classified by quartile, 63% of first and second hs-CRP measurements were in agreement; for total cholesterol it was 60%. Ninety percent of hs-CRP measurements were within one quartile of each other. This relationship was not altered by the use of log-transformed hs-CRP data. Conclusion: hs-CRP has a degree of measurement stability that is similar to that of total cholesterol.

Journal ArticleDOI
01 Dec 2001-Immunity
TL;DR: It is concluded that CTL exert positive selection pressure against the HCV quasispecies and the outcome of infection is predicted by mutations in class I MHC restricted epitopes.

Journal ArticleDOI
TL;DR: There is very little evidence to support or refute active commuting to school as an important source of childrens’ physical activity; however, this is largely because it has been overlooked in the stampede to assess time in more vigorous activities.
Abstract: The assessment and promotion of children's healthful physical activity is important: (i) to combat the international obesity epidemic that extends to childhood; and (ii) to establish an early habit of lifestyle physical activity that can be sustained into adolescence and adulthood The primary focus of both assessment and promotion efforts has been on in-school physical education classes and, to a lesser extent, out-of-school structured exercise, sport and play A potential source of continuous moderate activity, active commuting to school by means of walking or by bicycle, has been largely ignored in surveys of physical activity Suggestive evidence of steep declines in the amount of children's destination walking can be gleaned from national transportation surveys At the same time, there has been a dramatic increase in the reported use of motorised vehicles, including the use for chauffeuring children There is very little evidence to support or refute active commuting to school as an important source of children's physical activity; however, this is largely because it has been overlooked in the stampede to assess time in more vigorous activities The promotion of active commuting to school must be considered in the context of parents' real and perceived concerns for their children's personal and pedestrian safety We certainly do not have a full understanding at this time of all the factors related to decisions about transportation mode, whether by child, parent, community, or school Such information is necessary if successful and sustainable interventions can be implemented, important transport policy decisions can be made, and community and school designs can be modified Practice rarely waits for research, however, and there are numerous examples of innovative programming, policies and environmental designs occurring internationally that can serve as natural experiments for enterprising researchers willing to push the envelope of our understanding of active commuting and children's physical activity Since we know so little, there is much to learn KW: SR2S Language: en