bluuebunny/crossref_metadata_2025_split huggingface dataset:
Matrix comparison, Part 2: Measuring the resemblance between proximity measures or ordination results by use of the mantel and procrustes statistics
Authors: Schneider Jesper W. , Borlund Pia 
Published: July 2007

AbstractThe present two‐part article introduces matrix comparison as a formal means for evaluation purposes in informetric studies such as cocitation analysis. In the first part, the motivation behind introducing matrix comparison to informetric studies, as well as two important issues influencing such comparisons, matrix generation, and the composition of proximity measures, are introduced and discussed. In this second part, the authors introduce and thoroughly demonstrate two related matrix comparison techniques the Mantel test and Procrustes analysis, respectively. These techniques can compare and evaluate the degree of monotonicity between different proximity measures or their ordination results. In common with these techniques is the application of permutation procedures to test hypotheses about matrix resemblances. The choice of technique is related to the validation at hand. In the case of the Mantel test, the degree of resemblance between two measures forecast their potentially different affect upon ordination and clustering results. In principle, two proximity measures with a very strong resemblance most likely produce identical results, thus, choice of measure between the two becomes less important. Alternatively, or as a supplement, Procrustes analysis compares the actual ordination results without investigating the underlying proximity measures, by matching two configurations of the same objects in a multidimensional space. An advantage of the Procrustes analysis though, is the graphical solution provided by the superimposition plot and the resulting decomposition of variance components. Accordingly, the Procrustes analysis provides not only a measure of general fit between configurations, but also values for individual objects enabling more elaborate validations. As such, the Mantel test and Procrustes analysis can be used as statistical validation tools in informetric studies and thus help choosing suitable proximity measures.
Matrix comparison, Part 1: Motivation and important issues for measuring the resemblance between proximity measures or ordination results
Authors: Schneider Jesper W. , Borlund Pia 
Published: July 2007

AbstractThe present two‐part article introduces matrix com‐parison as a formal means of evaluation in informetric studies such as cocitation analysis. In this first part, the motivation behind introducing matrix comparison to informetric studies, as well as two important issues influencing such comparisons, are introduced and discussed. The motivation is spurred by the recent debate on choice of proximity measures and their potential influence upon clustering and ordination results. The two important issues discussed here are matrix generation and the composition of proximity measures. The approach to matrix generation is demonstrated for the same data set, i.e., how data is represented and transformed in a matrix, evidently determines the behavior of proximity measures. Two different matrix generation approaches, in all probability, will lead to different proximity rankings of objects, which further lead to different ordination and clustering results for the same set of objects. Further, a resemblance in the composition of formulas indicates whether two proximity measures may produce similar ordination and clustering results. However, as shown in the case of the angular correlation and cosine measures, a small deviation in otherwise similar formulas can lead to different rankings depending on the contour of the data matrix transformed. Eventually, the behavior of proximity measures, that is whether they produce similar rankings of objects, is more or less data‐specific. Consequently, the authors recommend the use of empirical matrix comparison techniques for individual studies to investigate the degree of resemblance between proximity measures or their ordination results. In part two of the article, the authors introduce and demonstrate two related statistical matrix comparison techniques the Mantel test and Procrustes analysis, respectively. These techniques can compare and evaluate the degree of monotonicity between different proximity measures or their ordination results. As such, the Mantel test and Procrustes analysis can be used as statistical validation tools in informetric studies and thus help choosing suitable proximity measures.
Illusory correlations in perceptions and predictions of organizational traits
Authors: Camerer Colin 
Published: July 2007

AbstractPeople often believe in ‘illusory’ correlations between variables that are similar, but not actually correlated. This study suggests that judgments of organizational traits reflect illusory correlations, because subjects' perceptions of correlations between traits, and the predictions of Hage's (1965) ‘axiomatic’ theory, were more highly correlated with independent similarity ratings than with actual correlations between traits. Some methodological reasons why organizational‐trait theories might unwittingly produce illusory correlation predictions are discussed, along with possible remedies.
Decisions, actions, and the appropriateness of confidence in knowledge
Authors: Paese Paul W. , Feuer Michael A. 
Published: July 2007

AbstractThis research examines the appropriateness of confidence (i.e., subjective probability judgments) in knowledge associated with decisions and actions of social importance. One hundred and thirty seven participants completed a 50 item questionnaire assessing their knowledge of the two leading candidates in the 1988 presidential election in the U.S.A. Ninety one of the respondents completed the questionnaire one week prior to the election, whereas the other 46 completed the questionnaire on election day shortly after voting. After each item in the questionnaire, all respondents indicated whether or not the item content represented a reason why they voted (or intended to vote) for or against the candidate to whom the item referred. Within‐person results indicated that, in comparison to items that were not cited as reasons for voting intentions or voting behavior, items endorsed as reasons were characterized by better accuracy and resolution, but worse overconfidence. Between groups, decision makers were significantly more accurate and better calibrated than those who had not made a decision between the candidates. Implications of inappropriate confidence on decision making effectiveness are discussed.
Judgment in a dynamic task: Microburst forecasting
Authors: Lusk Cynthia M. , Hammond Kenneth R. 
Published: July 2007

AbstractThe major goals of this research are to (a) study professionals engaging in dynamic, representative task conditions, (b) apply lens model theory to these conditions, (c) learn how judgments are changed in response to changing conditions, and (d) utilize a hierarchical judgment model to investigate the judgment process from perception of data to final judgment. The results indicate that (a) agreement regarding inferred cue values is modest, not because of differences in perception of proximal, directly observed cue values but because of differences in inferences drawn from them, (b) agreement in probability judgments is higher when inferred cue values are specified, (c) little change in judgments occurred over time, and (d) confidence increased over time. The results regarding agreement and accuracy over time were ambiguous.
The effects of screening and task partitioning upon evaluations of decision options
Authors: Van Zee Emily H. , Paluchowski Thaddeus F. , Beach Lee Roy 
Published: July 2007

AbstractSeven experiments examined how information used to screen options is used subsequently in evaluating the survivors before a choice of the best survivor is made and showed the following. (1) In general, information receiver early in the task had a smaller impact upon pre‐choice evaluations of options than information received later, whether or not screening had taken place. (2) However, early information had virtually no impact upon pre‐choice evaluations when various events partitioned the task into two distinct parts. This was called the ‘task‐partitioning effect’. This effect was, however, labile and could be eliminated by repeating the early information at the time that the pre‐choice evaluations were made. (3) In contrast, when the partitioning event consisted specifically of screening out unattractive options, early information had virtually no impact on evaluations and its repetition did not increase its use. This was called the ‘screening effect’. This effect was observed even when someone other than the subject carried out the screening.
The effect of constant outcome value on judgments and decision making given linguistic probabilities
Authors: Cohen Brent L , Wallsten Thomas S. 
Published: July 2007

AbstractTwo experiments were performed to determine whether judgments of the relative chances of two independent events occurring are biased by constant outcome values contingent on the events when the uncertainties are specified by linguistic expressions (e.g. doubtful). In Experiment 1, subjects directly judged the relative chances of the two events, of which one was represented by a spinner and the other by a linguistic probability expression. In Experiment 2, only linguistic probability expressions were used to describe the two events and a betting procedure was used. A bias was evident in both studies, such that the relative judgments tended to favour the event with the positive rather than the negative contingent outcome. The bias was smaller for the low‐ than for the high‐probability phrases. Individual differences were great, with the bias appearing strongly in only about one‐third of the population. Theoretical implications of the present and related results are discussed.
A theory of certainty equivalents for uncertain alternatives
Authors: Duncan Luce R. 
Published: July 2007

AbstractCertainty equivalents (CEs) of gambles are assumed to have a ratio scale representation that is strictly increasing in each consequence and the status quo is a singular point. A rank‐ and sign‐dependent weighted linear representation arises as follows. Gambles with both gains and losses are reduced to the formally equivalent binary alternative with the CEs of the subgambles of gains and of losses as consequences. A plausible and partially sustained, but non‐rational, assumption yields a bilinear, non‐additive form. Those gambles composed entirely of gains or entirely of losses are assumed to be rationally edited by subtracting from each consequence the utility of the consequence nearest the status quo and adding that amount to the utility of the modified gamble. A rank‐dependent, weighted average representation results in each domain separately. Because data using judged CEs of binary alternatives exhibit a pronounced non‐monotonicity at the status quo, a version of the theory is given that takes this into account.
The use of decomposition in probability assessments of continuous variables
Authors: Hora Stephen C. , Dodd Nancy G. , Hora Judith A. 
Published: July 2007

AbstractIn this study, decomposition is used as a tool for the assessment of continuous probability distributions. The goal of using decomposition is to obtain better calibrated probability distributions by expressing a variable as a known function of several component variables. Three target quantities were used in the study. Each was assessed holistically and using two different decompositions. Thus, each subject provided three distributions for each of the three target quantities. The recomposed assessments were compared to holistic assessments. The distributions obtained using decomposition were found to be much better calibrated than those obtained holistically. Two methods of aggregating distributions from multiple subjects were also examined. One involves aggregating (averaging) distributions before recomposing while the second method involves recomposing and then averaging distributions for the target variable. The second method was found to be slightly better, although both showed better calibration than was found in the individual assessments.
Order effects in belief updating with consistent and inconsistent evidence
Authors: Tubbs Richard M. , Gaeth Gary J. , Levin Irwin P. , Van Osdol Laura A. 
Published: July 2007

AbstractThe current study tests for the presence of differential order effects in evaluation tasks with consistent and inconsistent evidence as predicted by the Hogarth and Einhorn (1992) belief‐adjustment model. The results, based on both between‐subjects and within‐subjects experiments, demonstrate that there were significant recency effects with inconsistent evidence as predicted, larger recency effects when the inconsistent evidence was farther apart in subjective value as predicted, and significant recency effects even when subjects were given training designed to both help them understand the task as completely as possible and to be better able to assess the pieces of evidence. By including a within‐subjects design, we were able to demonstrate that the difference in subjective value between two pieces of evidence is the primary factor influencing the magnitude of the recency effect, regardless of whether the evidence is consistent or inconsistent. This latter finding is unique and contrary to previous research and theory.
An evaluation of the reliability of probability judgments across response modes and over time
Authors: Whitcomb Kathleen M. , Önkal Dilek , Benson P. George , Curley Shawn P. 
Published: July 2007

AbstractDespite the importance of probability assessment methods in behavioral decision theory and decision analysis, little attention has been directed at evaluating their reliability and validity. In fact, no comprehensive study of reliability has been undertaken. Since reliability is a necessary condition for validity, this oversight is significant. The present study was motivated by that oversight. We investigated the reliability of probability measures derived from three response modes: numerical probabilities, pie diagrams, and odds. Unlike previous studies, the experiment was designed to distinguish systematic deviations in probability judgments, such as those due to experience or practice, from random deviations. It was found that subjects assessed probabilities reliably for all three assessment methods regardless of the reliability measures employed. However, a small but statistically significant decrease over time in the magnitudes of assessed probabilities was observed. This effect was linked to a decrease in subjects overconfidence during the course of the experiment.
High‐density transient gene expression in suspension‐adapted 293 EBNA1 cells
Authors: Sun Xiangming , Hia Hui Ching , Goh Peen Ern , Yap Miranda G.S. 
Published: July 2007

AbstractLarge‐scale transient gene expression (TGE) in mammalian cells is an attractive method to rapidly produce recombinant proteins for pre‐clinical studies, with some processes reported to reach 100 L. However, the yield remains low, hardly over 20 mg protein/L, mainly because the current TGEs have been performed at low cell density (approximately 5 × 105 cells/mL). In this study, the strategy to improve TGE focuses on facilitating transfection at high cell density. A high‐density perfusion culture of 293 EBNA1 cells was established in 2‐L bioreactor using Freestyle 293 expression medium (Invitrogen, Singapore) to grow the cells for transfection. Transfection was then carried out at 1 × 107 cells/mL using polyethylenimine (PEI) as DNA carrier, at the optimized conditions of 6 µg DNA/107 cells and 1:3 DNA to PEI mass ratio. During the post‐transfection phase, 80.8 mg/L of the model protein, EPO was obtained at day 5.5 post‐transfection (130 mg total EPO production) using a fed‐batch culture mode. In comparison, perfusion cultures using an enriched SFM II medium resulted in a longer post‐transfection production phase (8 days), and 227 mg of EPO was produced in 10.7 L medium, showing that high‐density TGE enables the production of several hundreds of milligrams of protein in a 2 L bioreactor. In addition, a protocol for economical plasmid preparation based on anion exchange was also established to satisfy TGE's demand in terms of quality and quantity. To the best of our knowledge, this is the first report of transient transfections at a high cell density of up to 1 × 107 cells/mL. Biotechnol. Bioeng. 2008;99: 108–116. © 2007 Wiley Periodicals, Inc.
Determination of sodium tanshinone IIA sulfonate in plasma by liquid chromatography‐electrospray ionisation‐tandem mass spectrometry
Authors: Hao Haiping , Wang Guangji , Cui Nan , Li Jing , Ding Zuoqi 
Published: July 2007

AbstractSodium tanshinone IIA sulfonate (STS) is a water‐soluble derivative of tanshinone IIa, an important lipophilic component contained in Salvia miltiorrhizae. A simple, sensitive and robust quantification method for STS based on LC‐ESI‐MS/MS was developed and validated, and has been successfully applied to the pharmacokinetic study. Liquid–liquid extraction was used for extracting STS from biological samples, with a satisfactory recovery exceeding 75% at all test concentrations. Isocratic mobile phase consisted of 75% acetonitrile and 25% water containing 0.005% ammonia acetate (pH 3). Good retention and baseline separation for STS and the selected internal standard, diclofenac sodium, were obtained on a Shim‐pack VP‐ODS analytical column under this condition. The method was linear in the concentration range of 1–500 ng/mL. The intra‐ and inter‐day precisions (RSD%) were within 9.0%. The deviation of the assay accuracies was within ±10.0%. STS was proved to be stable during all sample storing, preparation and analytic procedures. With a lower limit of quantitation at 1 ng/mL, this method has been proved to be sensitive enough for the pharmacokinetic study of STS. The plasma profile of STS followed a single intravenous dosing was well fitted to a three compartmental model. Copyright © 2007 John Wiley & Sons, Ltd.
A steering model for on‐line locomotion synthesis
Authors: Kwon Taesoo , Shin Sung Yong 
Published: July 2007

AbstractFor applications such as video games and virtual walk‐throughs, on‐line locomotion control is an important issue. In general, the user prescribes a sequence of motions one by one while providing an input trajectory. Since the input trajectory lacks in human characteristics, one may not synthesize quality motions by blindly following it. In this paper, we present a novel data‐driven scheme for transforming a user‐prescribed trajectory to a human trajectory in an on‐line manner. As preprocessing, we analyze example motion data to extract human steering behavior. At run‐time, the input trajectory is refined to reflect the steering behavior. Together with an existing on‐line motion synthesis system, our scheme forms a feedback loop, in which the user effectively specifies an intended human trajectory. Copyright © 2007 John Wiley & Sons, Ltd.
Late or very late stent thrombosis can also occur with bare metal stents
Authors: Ramos Andres Rosas , Morice Marie‐claude , Lefèvre Thierry 
Published: July 2007

AbstractThe issue of late stent thrombosis (LAST) has become a subject of highly polemical debate over the past few months. Yet, both acute and LAST has always been a potential complication. The objective of this manuscript is to remind the readers, by means of two case reports, that thrombosis of bare metal stents may occur even very late after stent implantation. In the first case, stent thrombosis occurred after five years. In the second case, it occurred three years after the stenting procedure in a bare metal stent implanted in the circumflex artery of a patient who had also received two drug‐eluting stents in the left anterior descending coronary artery. © 2007 Wiley‐Liss, Inc.
Multiple Amplatzer septal occluder devices for multiple atrial communications: Immediate and long‐term follow‐up results
Authors: Awad Sawsan M. , Garay Francisco F. , Cao Qi‐Ling , Hijazi Ziyad M. 
Published: July 2007

AbstractObjectives: We report on the feasibility, effectiveness, and long‐term outcome of transcatheter closure of multiple ASD's using multiple ASO devices. Background: Little is known about the use and long‐term outcome of multiple Amplatzer Septal Occluder (ASO) devices to close multiple atrial septal defects (ASD's). Methods: From May 1997 to June 2006, 33 patients (mean age 38.9 years and mean weight 68 kg) underwent transcatheter closure of multiple ASD's under transesophageal (TEE) or intracardiac echocardiographic (ICE) guidance. Results: Unless not available, the device size chosen to be deployed was ±2 mm larger than the stretched diameter or no more than 30–40% larger than the ICE/TEE 2D diameter. Sixty‐seven devices were deployed in 33 patients. The mean diameters of the larger and smaller defects were 12.9 and 7.7 mm, and the corresponding mean balloon stretched diameters were 19.2 and 12.0 mm, respectively. The mean larger and smaller device diameters were 19.0 and 13.4 mm, respectively. The mean QP: Qs ratio was 1.8:1. The mean fluoroscopy time, and procedure time were 16.4 and 81.6 min respectively. Immediately after the procedure 15 patients had complete closure, 8 had trivial shunt, 9 had small shunt and one had large shunt. Complications included a device embolization within 24 hr and left atrial‐aortic wall erosion and pericardial effusion at 2 years. The mean follow‐up interval was 34.8 + 25.7 months. Conclusions: Device closure of multiple ASD's using multiple ASO's is safe and effective. Continued follow‐up is important to assess the long‐term outcome. © 2007 Wiley‐Liss, Inc.
Carotid artery stent type influences duplex ultrasonography derived peak systolic velocity: Findings of an in‐vitro model
Authors: Spies Christian , Doshi Ripple , Spoon Jocelyn , Snell R. Jeffrey 
Published: July 2007

AbstractObjective: The goal of this study is to evaluate the effect of stenting on Doppler ultrasonography (DU) [velocity] signals in an in‐vitro carotid model. Background: Considerable debate exists about whether DU overestimates velocity signals and thus the degree of stenosis in previously stented carotid arteries. Methods: Constant, pulsatile flow was simulated with an experimental circulatory system containing a nonstenotic ovine internal carotid artery segment. Peak systolic velocity (PSV) and peak diastolic velocity were measured with an intravascular flow wire (FW) and DU. Velocities were evaluated at five predetermined locations within the vessel immediately prior to and following stent placement. Results: Eleven stents were implanted. DU‐derived PSV increased significantly following placement of the X‐Act stent (80 ± 26 cm/sec [pre] vs. 102 ± 29 cm/sec [post], P = 0.02), while FW‐derived PSV (65 ± 23 cm/sec [pre] vs. 66 ± 9 cm/sec [post], P = 0.93) did not change. The Precise stent did not influence PSV with either method (DU: 76 ± 28 cm/sec [pre] vs. 72 ± 35 cm/sec [post], P = 0.95;), while the Acculink stent showed a trend towards a reduction in DU (69 ± 37 cm/sec [pre] vs. 51 ± 10 cm/sec [post], P = 0.075) and FW (50 ± 27 cm/sec [pre] vs. 40 ± 12 cm/sec [post], P = 0.14) derived PSV. Peak diastolic velocity revealed similar trends as PSV signals depending on the type of stent used. Conclusions: Stent type may have significant impact on DU derived velocity signals. DU seems to overestimate PSV in carotid arteries treated with the X‐Act stent, but not with the Precise or Acculink stent. Larger scale clinical comparison of various stent types and their impact on DU are needed in order to clarify the value of DU surveillance following carotid artery stenting. © 2007 Wiley‐Liss, Inc.