bluuebunny/crossref_metadata_2025_split huggingface dataset:
Failure Modes with Point Loading of Three Commercially Available Denture Teeth
Authors: Moffitt Andrew R. , Woody Ronald D. , Parel Stephen M. , Miller Barbara H. 
Published: May 2008

Abstract Purpose: A common problem associated with implant‐supported prostheses is the fracture of denture teeth. This study was designed to compare the fracture modes of three denture teeth by compressive load at a 30° off‐axis angle. Material and Methods: Three denture teeth (Vident Duostat, Ivoclar Vivadent, and Dentsply Trubyte) processed to two denture base processing systems [injection‐molded (IM) SR‐Ivocap system and compression‐molded (CM) denture base resin] were evaluated. Each specimen was processed to a metal framework. Ultimate failure strength of each system when point loaded at a 30° off‐axis angle was recorded, along with a visual inspection of each specimen. Results: The average load fracture for each group was (in N): Vident CM 1106.97 ± 223.20, Vident IM 1168.18 ± 322.52, Dentsply CM 1098.08 ± 286.32, Dentsply IM 1023.80 ± 282.45, Ivoclar CM 1616.98 ± 204.87, and Ivoclar IM 1373.54 ± 282.58. There was a significant difference between the groups and the Ivoclar CM group. The Ivoclar CM group had the highest average load force, and the Dentsply IM group had the lowest average load force. On average, the teeth within the groups fractured at a higher compression force than the average maximum occlusal force in natural dentition. Dentsply and Vident denture teeth fractured more horizontally, and the Ivoclar denture teeth fractured more vertically within the groups. There was no significant difference among the groups between the IM and CM processing methods. Conclusions: In the present in vitro study, all specimens were able to withstand 30° off‐axis loading with the exception of one specimen. With these results, this would indicate that these denture teeth are able to withstand normal occlusal forces.
Technology Acceptance Model 3 and a Research Agenda on Interventions
Authors: Venkatesh Viswanath , Bala Hillol 
Published: May 2008

ABSTRACTPrior research has provided valuable insights into how and why employees make a decision about the adoption and use of information technologies (ITs) in the workplace. From an organizational point of view, however, the more important issue is how managers make informed decisions about interventions that can lead to greater acceptance and effective utilization of IT. There is limited research in the IT implementation literature that deals with the role of interventions to aid such managerial decision making. Particularly, there is a need to understand how various interventions can influence the known determinants of IT adoption and use. To address this gap in the literature, we draw from the vast body of research on the technology acceptance model (TAM), particularly the work on the determinants of perceived usefulness and perceived ease of use, and: (i) develop a comprehensive nomological network (integrated model) of the determinants of individual level (IT) adoption and use; (ii) empirically test the proposed integrated model; and (iii) present a research agenda focused on potential pre‐ and postimplementation interventions that can enhance employees' adoption and use of IT. Our findings and research agenda have important implications for managerial decision making on IT implementation in organizations.
Growth versus Margins: Destabilizing Consequences of Giving the Stock Market What It Wants
Authors: AGHION PHILIPPE , STEIN JEREMY C. 
Published: May 2008

ABSTRACTWe develop a model in which a firm can devote effort either to increasing sales growth, or to improving per‐unit profit margins. If the firm's manager cares about the current stock price, she will favor the growth strategy when the market pays more attention to growth numbers. Conversely, it can be rational for the market to weight growth measures more heavily when it is known that the firm is following a growth strategy. This two‐way feedback between firms' strategies and the market's pricing rule can lead to excess volatility in real variables, even absent any external shocks.
Volatility Information Trading in the Option Market
Authors: NI SOPHIE X. , PAN JUN , POTESHMAN ALLEN M. 
Published: May 2008

ABSTRACTThis paper investigates informed trading on stock volatility in the option market. We construct non‐market maker net demand for volatility from the trading volume of individual equity options and find that this demand is informative about the future realized volatility of underlying stocks. We also find that the impact of volatility demand on option prices is positive. More importantly, the price impact increases by 40% as informational asymmetry about stock volatility intensifies in the days leading up to earnings announcements and diminishes to its normal level soon after the volatility uncertainty is resolved.
The Corporate Governance Role of the Media: Evidence from Russia
Authors: DYCK ALEXANDER , VOLCHKOVA NATALYA , ZINGALES LUIGI 
Published: May 2008

ABSTRACTWe study the effect of media coverage on corporate governance by focusing on Russia in the period 1999 to 2002. We find that an investment fund's lobbying increases coverage of corporate governance violations in the Anglo‐American press. We also find that coverage in the Anglo‐American press increases the probability that a corporate governance violation is reversed. This effect is present even when we instrument coverage with an exogenous determinant, the fund's portfolio composition at the beginning of the period. The fund's strategy seems to work in part by impacting Russian companies' reputation abroad and in part by forcing regulators into action.
Stock Returns in Mergers and Acquisitions
Authors: HACKBARTH DIRK , MORELLEC ERWAN 
Published: May 2008

ABSTRACTThis paper develops a real options framework to analyze the behavior of stock returns in mergers and acquisitions. In this framework, the timing and terms of takeovers are endogenous and result from value‐maximizing decisions. The implications of the model for abnormal announcement returns are consistent with the available empirical evidence. In addition, the model generates new predictions regarding the dynamics of firm‐level betas for the period surrounding control transactions. Using a sample of 1,086 takeovers of publicly traded U.S. firms between 1985 and 2002, we present new evidence on the dynamics of firm‐level betas, which is strongly supportive of the model's predictions.
A Search‐Based Theory of the On‐the‐Run Phenomenon
Authors: VAYANOS DIMITRI , WEILL PIERRE‐OLIVIER 
Published: May 2008

ABSTRACTWe propose a model in which assets with identical cash flows can trade at different prices. Infinitely lived agents can establish long positions in a search spot market, or short positions by first borrowing an asset in a search repo market. We show that short‐sellers can endogenously concentrate in one asset because of search externalities and the constraint that they must deliver the asset they borrowed. That asset enjoys greater liquidity, a higher lending fee (“specialness”), and trades at a premium consistent with no‐arbitrage. We derive closed‐form solutions for small frictions, and provide a calibration generating realistic on‐the‐run premia.
The Politics of Financial Development: Evidence from Trade Liberalization
Authors: BRAUN MATIAS , RADDATZ CLAUDIO 
Published: May 2008

ABSTRACTIncumbents in various industries have different incentives to promote or oppose financial development. Changes in the relative strength of promoter and opponent industries thus result in changes in the political equilibrium level of financial development. We conduct an event study using a sample of 41 countries that liberalized trade during 1970 to 2000, and show that the strengthening of promoter relative to opponent industries resulting from liberalization is a good predictor of subsequent financial development. The benefits of developing the financial system are insufficient for financial development, and rents in particular hands appear to be necessary to achieve it.
Intracoronary Infusion of Catecholamines Causes Focal Arrhythmias in Pigs
Authors: DOPPALAPUDI HARISH , JIN QI , DOSDALL DEREK J. , QIN HAO , WALCOTT GREGORY P. , KILLINGSWORTH CHERYL R. , SMITH WILLIAM M. , IDEKER RAYMOND E. , HUANG JIAN 
Published: May 2008

Background:
Acute ischemia causes myriad changes including increased catecholamines. We tested the hypothesis that elevated catecholamines alone are arrhythmogenic.
Methods and Results:
A 504 electrode sock was placed over both ventricles in six open‐chest pigs. During control infusion of saline through a catheter in the left anterior descending coronary artery (LAD), no sustained arrhythmias occurred, and the refractory period estimated by the activation recovery interval (ARI) was 175 ± 14 ms in the LAD bed below the catheter. After infusion of isoproterenol at 0.1 μg/kg/min through the catheter, the ARI in this bed was significantly reduced to 109 ± 10 ms. A sharp gradient of refractoriness of 43 ± 10 ms was at the border of the perfused bed. Sustained monomorphic ventricular tachycardia occurred after drug infusion in the perfused bed or near its boundary in all animals with a cycle length of 329 ± 26 ms and a focal origin. The maximum slope of the ARI restitution curve at the focal origins of the tachyarrhythmias was always <1 (0.62 ± 0.15). Similar results with a focal arrhythmia origin occurred in two additional pigs in which intramural mapping was performed with 36 plunge needle electrodes in the left ventricular perfused bed.
Conclusion:
Regional elevation of a catecholamine, which is one of the alterations produced by acute ischemia, can by itself cause tachyarrhythmias. These arrhythmias are closely associated with a shortened refractory period and a large gradient of the spatial distribution of refractoriness but not with a steep restitution curve.
Effects of Procainamide and Sotalol on Restitution Properties, Dispersion of Refractoriness, and Ventricular Fibrillation Activation Patterns in Pigs
Authors: JIN QI , CHEN XIAOZHONG , SMITH WILLIAM M. , IDEKER RAYMOND E. , HUANG JIAN 
Published: May 2008

Background:
Interest in combining antiarrhythmic drugs has been prompted by the lack of efficacy of monotherapies and the toxicity resulting from high doses of individual agents.
Objectives:
We tested the hypothesis that procainamide and sotalol combined have greater beneficial effects on restitution, on the dispersion of refractoriness, and on decreasing the complexity of ventricular fibrillation (VF) than either drug alone.
Methods:
Six open‐chest pigs received intravenous procainamide (15 mg/kg load and 50 μg/kg/min maintenance) followed by sotalol (1.5 mg/kg). Another six pigs received sotalol first and procainamide second. Before drugs and after each drug, 20‐second episodes of electrically induced VF were recorded from a 21 × 24 unipolar electrode plaque (2 mm spacing) sutured on the lateral posterior left ventricular epicardium. Restitution properties and dispersion of refractoriness were estimated from activation recovery intervals during pacing.
Results:
The combination of the two drugs reduced the maximum slope of the restitution curve and during VF reduced the number of wavefronts, the activation rate, the percentage of wavefront families exhibiting reentry, and the conduction velocity more than either drug alone. In addition, in the group that received sotalol first, both drugs together reduced the SD and the coefficient of variation of the spatial dispersion of refractoriness compared with baseline.
Conclusions:
Procainamide and sotalol combined have greater beneficial effects on restitution properties, dispersion of refractoriness, and the complexity of VF than either drug alone compared with baseline.
Spatial Distribution and Extent of Electroporation by Strong Internal Shock in Intact Structurally Normal and Chronically Infarcted Rabbit Hearts
Authors: KIM SEOK C. , VASANJI AMIT , EFIMOV IGOR R. , CHENG YUANNA 
Published: May 2008

Introduction:
Although life‐saving, a strong internal defibrillation shock may temporarily or permanently damage the heart via disruption of cell membranes (electroporation). Spatial extent of electroporation in intact, normal, or infarcted hearts has not been investigated. In this study, shock‐induced electroporation in intact rabbit hearts with and without chronic (>4 weeks) left ventricular myocardial infarction (MI) was characterized.
Methods and Results:
A coil shock electrode was inserted in the right ventricle of Langendorff‐perfused hearts. One truncated exponential monophasic shock (+300 V, 8 ms) was delivered by a 150 μF capacitor clinical defibrillator while the heart was perfused with membrane‐impermeant dye propidium iodide (PI). The heart was sectioned transversely, and uptake of PI into ventricular myocardium through electropores was quantified. Histological evaluation was performed via Masson's trichrome staining. PI accumulation was minimal in the control (n = 3) and MI (n = 3) hearts without shock. Following shock delivery, (1) in control (n = 5) and MI (n = 5) hearts, electroporation mostly occurred near the shock electrode and was longitudinally distributed along the active region of the shock electrode; (2) in MI group, electroporation was significantly increased (P < 0.05) in the surviving anterior epicardial layers of the infarcted region; and (3) between the control and MI groups, the overall extent of electroporation was similar.
Conclusion:
Shock‐induced electroporation was spatially dependent on the location and dimension of the active region of the shock electrode. The overall extent of electroporation in the MI heart was comparable with the control heart, but the surviving anterior epicardial layers in the infarcted region were more susceptible to electroporation.
Learning from the Spirits: Candomblé, Umbanda, and Kardecismo in Recife, Brazil
Authors: KRIPPNER STANLEY 
Published: May 2008

ABSTRACTBrazilian spiritistic religions have developed along elaborate historical and cultural trajectories with spirit mediumship as a central feature of ritual practice in Candomblé, Umbanda, Kardecismo, and similar groups. In these studies, several Brazilian spiritistic practitioners who worked as mediums were interviewed and, in some cases, tested with psychological measures for dissociation using the Dissociative Experiences Scale, for absorption using the Tellegen Absorption Scale, and for sexual orientation using the Kinsey Scale. Few significant gender differences were noted in these measures. In two cases, psychophysiological measures were employed including electroencephalography, heart rate, skin conductance, and electromyography. In general, the research participants scored highly on measures of dissociation while scoring in the average range on absorption (using U.S. norms). The psychophysiological results indicated that for the two spiritistic practitioners investigated overall peripheral autonomic nervous system activation was negatively associated with sympathetic cortical level deactivation. The data suggested a psychophysiological incongruence between the central nervous system and the peripheral nervous system functioning on the part of the two practitioners. However, the two variables were positively associated and congruent in data obtained from a control subject. Interview data identified five ways in which mediums received their “call to heal,” visions, dreams, and unexpected incorporations being the most frequent factors cited. One medium who engages in surgical procedures was observed; tissues were collected from ten clients and were found to be consistent with the site of the surgery. In conclusion, it is apparent that mediumship is a complex phenomenon, one deserving of further investigation by anthropologists, psychologists, and sociologists interested in human consciousness, in indigenous health care, and in the psychophysiology of practitioners who claim to work under the direction of spirit entities.
Yanomami Shamanic Initiation: The Meaning of Death and Postmortem Consciousness in Transformation
Authors: JOKIC ZELJKO 
Published: May 2008

ABSTRACTThe main aim of shamanic initiation among the Yanomami people of the Upper Orinoco River region in Venezuela is the metamorphosis of the human body into a cosmic body, or what I term “corporeal cosmogenesis.” During the initiatory ordeal, the neophyte undergoes an intense experience of death through dismemberment by the spirits and subsequent rebirth, thus overcoming the human condition and becoming an individual living spirit. But, at the same time, he becomes a “collection” of other spirits who leave their natural habitats—located on the mountaintops and in the forest—and move into the initiate's body, which becomes their abode. As the candidate surrenders his soul and humanness to the spirits, the latter become his personal allies and sources of power while imbuing the shaman's postmortem ego with certain properties that can best be described in holographic terms. After the shaman's biological death, his personal spirits become disembodied again and disperse back into the forest and on the mountaintops. When the shaman dies, his soul multiplies, as each of the disembodied spirits becomes a carrier of the shaman's soul image. In this way, through initiations, the shaman becomes a part of a dynamic cosmic circuity, as his hekura can be called upon to invade the bodies of new shamans, and start a cosmogonic initiatory act anew.
Ego Boundaries, Shamanic‐Like Techniques, and Subjective Experience: An Experimental Study
Authors: ROCK ADAM J. , WILSON JESSICA M. , JOHNSTON LUKE J. , LEVESQUE JANELLE V. 
Published: May 2008

ABSTRACTThe subjective effects and therapeutic potential of the shamanic practice of journeying is well known. However, previous research has neglected to provide a comprehensive assessment of the subjective effects of shamanic‐like journeying techniques on non‐shamans. Shamanic‐like techniques are those that demonstrate some similarity to shamanic practices and yet deviate from what may genuinely be considered shamanism. Furthermore, the personality traits that influence individual susceptibility to shamanic‐like techniques are unclear. The aim of the present study was, thus, to investigate experimentally the effect of shamanic‐like techniques and a personality trait referred to as “ego boundaries” on subjective experience including mood disturbance. Forty‐three non‐shamans were administered a composite questionnaire consisting of demographic items and a measure of ego boundaries (i.e., the Short Boundary Questionnaire; BQ‐Sh). Participants were randomly assigned to one of three conditions: listening to monotonous drumming for 15 minutes coupled with one of two sets of journeying instructions; or sitting quietly with eyes closed for 15 minutes. Participants' subjective experience and mood disturbance were retrospectively assessed using the Phenomenology of Consciousness Inventory (PCI) and the Profile of Mood States‐Short Form, respectively. The results indicated that there was a statistically significant difference between conditions with regard to the PCI major dimensions of visual imagery, attention and rationality, and minor dimensions of imagery amount and absorption. However, the shamanic‐like conditions were not associated with a major reorganization of the pattern of subjective experience compared to the sitting quietly condition, suggesting that what is typically referred to as an altered state of consciousness effect was not evident. One shamanic‐like condition and the BQ‐Sh subscales need for order, childlikeness, and sensitivity were statistically significant predictors of total mood disturbance. Implications of the findings for the anthropology of consciousness are also considered.
Therapy of peri‐implantitis: a systematic review
Authors: Kotsovilis Sotirios , Karoussis Ioannis K. , Trianti Maria , Fourmousis Ioannis 
Published: May 2008

AbstractAim: The objective of this study was to provide a systematic review of randomized controlled and/or comparative clinical trials published in the international peer‐reviewed literature in the English language, up to and including July 2007, concerning the efficacy of all treatment modalities implemented for the therapy of peri‐implantitis.Material and Methods: PubMed and The Cochrane Library databases were searched electronically and numerous journals were examined manually. In the first phase of selection, the titles and abstracts, and in the second phase, complete papers were screened independently and in duplicate by three reviewers (S. K., I. K. K. and M. T.).Results: The search yielded 1304 possibly relevant titles and abstracts. After the first phase of selection, 13 publications were singled out for a rigorous evaluation. Following the second phase, five studies were selected.Conclusions: The selected studies are too limited in number and exhibit small sample sizes and short follow‐up periods. Therefore, there is a definite need for more well‐designed, preferably longitudinal, randomized controlled clinical trials. Within the limitations of the selected studies, mechanical debridement combined with antiseptic/antibiotic therapy, the Er:YAG laser or regenerative techniques may be used for treating peri‐implantitis, but the indications for each of these techniques have not been delineated clearly.
Evaluation of a community‐based weight management program for overweight and obese adolescents: The Loozit study
Authors: O'CONNOR Janice , STEINBECK Katharine , HILL Andrew , BOOTH Michael , KOHN Michael , SHAH Smita , BAUR Louise 
Published: May 2008

AbstractAim: To evaluate a community‐based weight management program for overweight and obese adolescents aged 13–16 years.Methods: The present study was a group‐based intervention over five months conducted in Australian community health centres. Program evaluation questionnaires were completed by adolescents and their parents. Seven semi‐structured group sessions were held for adolescents: weekly for four weeks and then at two, four and five months. The program sessions focused on healthy eating, increasing physical activity, decreasing sedentary behaviour and increasing self‐esteem. Adolescents' anthropometry, blood pressure and fasting blood biochemistry were measured. Adolescents completed validated questionnaires on diet, physical activity and self‐esteem.Results: Twenty‐two overweight and obese adolescents were recruited with a median body mass index (BMI) z‐score 2.30. Recruitment strategies were identified and a high retention rate (91%) was achieved. The program was well received by adolescents. Parents reported their adolescents were making healthier food choices and increasing physical activity. At treatment end there were clinically significant improvements in self‐perception scores for physical appearance and romantic appeal (P < 0.05), waist circumference (median 100.1 cm vs 97.1 cm;P < 0.0001) and HDL cholesterol (median 1.10 mmol/L vs 1.20 mmol/L;P = 0.02), but not BMI or BMI z‐score.Conclusions: The Loozit weight management intervention is one of the first to involve adolescents in the evaluation of the program and to operate at a sustainable intensity in an accessible community setting. The present study provides valuable insights into the elements of a program that is acceptable to adolescents.