bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of the Flexural Strength of Five Adhesive Resin Cements
Authors: Pace Larry L. , Hummel Susan K. , Marker Victoria A. , Bolouri Ali 
Published: January 2007

Statement of Problem: The increased use of adhesive resin cements in bonded prosthetic restorations has led to restorations debonding under function.
Purpose: This investigation evaluated the differences in the flexural strength of new adhesive resin cements as a function of specimen age and storage condition.
Materials and Methods: Four new dual‐cure cements were compared to C/B Metabond. Twenty specimens of each of the five cements were prepared in a rectangular glass mold (25 × 2 × 2 mm). The new cements were light‐activated with a 550 mW/cm2 lamp for 80 seconds on both the top and bottom surfaces. The auto‐cured cement was allowed to set according to manufacturer's directions. Half the specimens were tested immediately after curing while the other half were stored in distilled water at 37°C for 30 days. A three‐point bending test was performed using an Instron at a crosshead speed of 1 mm/min. The results were analyzed by analysis of variance and Scheffé tests ( p < 0.05) to examine the effect of specimen age and storage condition.
Results: RelyX ARC exhibited a significantly higher flexural strength compared with Calibra and Panavia F when tested immediately. The standard cement, C/B Metabond, deformed and did not fracture at the immediate test time. After storage, the flexural strength had significantly improved from the immediate test time for Calibra, Cement‐It, Panavia F, and C/B Metabond. However, there were no significant differences in the flexural strength among the cements when tested after 30 days in water at 37°C.
Conclusion: Immediately after curing, these new adhesive resin cements are not equivalent, as evidenced by the significant variability in the measured flexural strength. The distinctions among the cements diminish after aging in water, which may be due to residual polymerization or a plasticizing effect from water absorption.
Clinical Significance: When light‐cured, all the new adhesive resin cements have greater early strengths than the auto‐cured cement; however, the wide variation in immediate bending strength suggests that some cements may be more appropriate for use in high‐stress clinical situations such as resin‐bonded fixed partial dentures.
Conventional Rehabilitation of Edentulous Patients: The Impact on Oral Health‐Related Quality of Life and Patient Satisfaction
Authors: Ellis Janice S. , Pelekis Nanita D. , Thomason J. Mark 
Published: January 2007

Purpose: This study examined patient satisfaction and oral health‐related impacts on the quality of life of patients restored with complete conventional or duplicate dentures.
Materials and Methods: Forty patients (aged 55 to 85 years) were assigned to receive new complete maxillary and mandibular dentures using either a conventional or duplication technique according to clinical need. Patients rated their satisfaction with their dentures on 100‐mm visual analogue scales before treatment and 1 month after delivery of their new dentures. Their oral health‐related quality of life was determined by completion of an Oral Health‐Related Impacts on Quality of Life questionnaire (OHIP‐20) at the same time points.
Results: Both groups of patients had similar satisfaction and OHIP ratings at the beginning of the study and 1 month after delivery of their new dentures. The two groups were comparable with regard to age and gender. Statistically significant improvement in the OHIP domains of functional limitation and physical and psychological disability was seen in both groups. The conventional group also showed significant improvement with regard to handicap, whereas the duplicate denture group showed significant improvement in the patients' rating of pain and psychological discomfort. Patient satisfaction improved significantly in both groups across all variables except ease of cleaning and ability to speak. The duplication technique resulted in patients being less satisfied with the esthetics of their new dentures.
Conclusion: In this study, the provision of new dentures either with a conventional technique or with a duplication technique resulted in an overall improvement in oral health‐related quality of life and satisfaction. These improvements were statistically significant for some domains, which varied depending on the technique used for construction of the new dentures. Neither technique was seen to be superior, which may be a reflection of the patients' treatment expectations at the outset. Patients' reported satisfaction with their dentures and the impact that dentures have on their quality of life may not be useful measures for determining the most appropriate technique for providing new dentures.
The functional immaturity of dendritic cells can be relevant to increased tolerance associated with cord blood transplantation
Authors: Encabo Araceli , Solves Pilar , Carbonell‐Uberos Francisco , Miñana Maria Dolores 
Published: January 2007

BACKGROUND: Cord blood (CB) transplants have a significantly lower incidence of graft‐versus‐host disease (GVHD) compared to marrow or peripheral blood transplants. Because antigen‐presenting cells and regulatory T cells (Treg) are involved in transplant tolerance, this study was aimed at analyzing the distribution of dendritic cells (DCs) and CD14+ monocyte–specific subsets in CB and adult peripheral blood (APB) and comparing the ability of DCs from these two blood sources to induce CD4+ Treg.STUDY DESIGN AND METHODS: Myeloid DCs (mDCs), plasmacytoid DCs, the CD14+ cell subsets CD14+CD16+ and CD14+CD209+, and CD4+ T cells were analyzed by fluorescence‐activated cell sorting (FACS) in whole blood. To evaluate the functionality of DCs, isolated CD3+ T cells from an adult donor were cultured with allogenic DC‐enriched fraction from CB or APB, and CD4+ Treg generation was determined by FACS. Additionally, tumor necrosis factor (TNF)‐α and interferon (IFN)‐α release by DCs was measured.RESULTS: CB had a lesser frequency of DCs and specific CD14+ monocyte subsets than APB. After stimulation, monocytes from CB secreted less TNF‐α than those from APB. Moreover, DCs from CB exhibited a more immature phenotype and had a decreased capacity to release TNF‐α and IFN‐α than those derived from APB, but on the contrary, they were efficient inducers of CD4+ T cells with a phenotype of Treg.CONCLUSION: The tolerogenic immunophenotype and diminished functionality of CB DCs can be important to create a microenvironment where Treg develop, that in turn may be relevant to observed lower incidence of chronic GVHD after CB transplantation.
Cardioprotective effects of acute normovolemic hemodilution in patients with severe aortic stenosis undergoing valve replacement
Authors: Licker Marc , Sierra Jorge , Kalangos Afksendiyos , Panos Aristote , Diaper John , Ellenberger Christoph 
Published: January 2007

BACKGROUND: After acute normovolemic hemodilution (ANH), improvement of the rheologic conditions may contribute to optimize tissue oxygen delivery and attenuate ischemia‐reperfusion injuries. It was hypothesized that ANH would confer additional cardioprotection in patients with ventricular hypertrophy undergoing open heart surgery.STUDY DESIGN AND METHODS: This study was a randomized controlled trial. Forty patients scheduled for elective aortic valve replacement were randomly assigned to a control group (standard care) or an ANH group (target hematocrit level of 28%). All patients were managed with standard myocardial preservation techniques (cold blood cardioplegia, anesthetic preconditioning). The outcome measures included the release of myocardial enzymes, perioperative hemodynamic changes, the need for pharmacologic cardiovascular support, and cardiac complications.RESULTS: In the ANH group, the postoperative release of troponin I (mean peak plasma concentrations, 1.7 ng/mL; 95% confidence interval, 1.4‐2.1 ng/mL) and myocardial fraction of creatine kinase (22 U/L; range, 18‐24 U/L) was significantly lower than in the control group (3.6 [range, 3.0‐4.2] ng/mL and 45 [range, 39‐51] U/L, respectively). In addition, requirement for inotropic support was significantly lower and fewer hemodiluted patients presented adverse cardiac events. After ANH, there was a significant decrease in heart rate (−11 ± 6%) and rate‐pressure product (−16 ± 8%) until the aortic cross‐clamping time and, at the end of surgery, the circulating levels of erythropoietin (EPO) were higher than in control patients (13.6 ± 4.2 mUI/mL vs. 7.3 ± 2.4 mUI/mL; p < 0.05).CONCLUSIONS: Besides conventional cardiac preservation techniques, preoperative ANH further attenuates myocardial injuries. Optimization of preischemic myocardial oxygen delivery and/or consumption and the postconditioning effects of endogenous EPO are potential mechanisms for ANH‐induced cardioprotection.
Political Connections and Corporate Bailouts
Authors: FACCIO MARA , MASULIS RONALD W. , McCONNELL JOHN J. 
Published: January 2007

ABSTRACTWe analyze the likelihood of government bailouts of 450 politically connected firms from 35 countries during 1997–2002. Politically connected firms are significantly more likely to be bailed out than similar nonconnected firms. Additionally, politically connected firms are disproportionately more likely to be bailed out when the International Monetary Fund or the World Bank provides financial assistance to the firm's home government. Further, among bailed‐out firms, those that are politically connected exhibit significantly worse financial performance than their nonconnected peers at the time of and following the bailout. This evidence suggests that, at least in some countries, political connections influence the allocation of capital through the mechanism of financial assistance when connected companies confront economic distress.
A Theory of Pyramidal Ownership and Family Business Groups
Authors: ALMEIDA HEITOR V. , WOLFENZON DANIEL 
Published: January 2007

ABSTRACTWe provide a new rationale for pyramidal ownership in family business groups. A pyramid allows a family to access all retained earnings of a firm it already controls to set up a new firm, and to share the new firm's nondiverted payoff with shareholders of the original firm. Our model is consistent with recent evidence of a small separation between ownership and control in some pyramids, and can differentiate between pyramids and dual‐class shares, even when either method can achieve the same deviation from one share–one vote. Other predictions of the model are consistent with both systematic and anecdotal evidence.
Estimating the Gains from Trade in Limit‐Order Markets
Authors: HOLLIFIELD BURTON , MILLER ROBERT A. , SANDÅS PATRIK , SLIVE JOSHUA 
Published: January 2007

ABSTRACTWe present a method to estimate the gains from trade in limit‐order markets and provide empirical evidence that the limit‐order market is a good market design. Using observations on order submissions and execution and cancellation histories, we estimate both the distribution of traders' unobserved valuations for the stock and latent trader arrival rates. We use the resulting estimates to compute the current gains from trade, the gains from trade in a perfectly liquid market, and the gains from trade with a monopoly liquidity supplier. The current gains are 90% of the maximum gains and 150% of the monopolist gains.
Insider Trading, News Releases, and Ownership Concentration
Authors: FIDRMUC JANA P. , GOERGEN MARC , RENNEBOOG LUC 
Published: January 2007

ABSTRACTThis paper investigates the market's reaction to U.K. insider transactions and analyzes whether the reaction depends on the firm's ownership. We present three major findings. First, differences in regulation between the U.K. and United States, in particular the speedier reporting of trades in the U.K., may explain the observed larger abnormal returns in the U.K. Second, ownership by directors and outside shareholders has an impact on the abnormal returns. Third, it is important to adjust for news released before directors' trades. In particular, trades preceded by news on mergers and acquisitions and CEO replacements contain significantly less information.
When Financial Institutions Are Large Shareholders: The Role of Macro Corporate Governance Environments
Authors: LI DONGHUI , MOSHIRIAN FARIBORZ , PHAM PETER KIEN , ZEIN JASON 
Published: January 2007

ABSTRACTWhile financial institutions' aggregate investments have grown substantially worldwide, the size of their individual shareholdings, and ultimately their incentive to monitor, may be limited by the free‐rider problem, regulations, and a preference for diversification and liquidity. We compare institutions' shareholding patterns across countries and find vast differences in the extent to which they are large shareholders. These variations are largely determined by macro corporate governance factors such as shareholder protection, law enforcement, and corporate disclosure requirements. This suggests that strong governance environments act to strengthen monitoring ability such that more institutions are encouraged to hold concentrated equity positions.
Analyst Coverage and Financing Decisions
Authors: CHANG XIN , DASGUPTA SUDIPTO , HILARY GILLES 
Published: January 2007

ABSTRACTWe provide evidence that analyst coverage affects security issuance. First, firms covered by fewer analysts are less likely to issue equity as opposed to debt. They issue equity less frequently, but when they do so, it is in larger amounts. Moreover, these firms depend more on favorable market conditions for their equity issuance decisions. Finally, debt ratios of less covered firms are more affected by Baker and Wurgler's (2002)“external finance‐weighted” average market‐to‐book ratio. These results are consistent with market timing behavior associated with information asymmetry, as well as behavior implied by dynamic adverse selection models of equity issuance.
Derivative Pricing 60 Years before Black–Scholes: Evidence from the Johannesburg Stock Exchange
Authors: MOORE LYNDON , JUH STEVE 
Published: January 2007

ABSTRACTWe obtain daily data for warrants traded on the Johannesburg Stock Exchange between 1909 and 1922, and for a broker's call option quotes on stocks from 1908 to 1911. We use this new data set to test how close derivative prices are to Black–Scholes (1973) prices and to compute profits for investors using a simple trading rule for call options. We examine whether investors exercised warrants optimally and how they reacted to extensions of the warrants' durations. We show that long before the development of the formal theory, investors had an intuitive grasp of the determinants of derivative pricing.
Why Do Firms Issue Equity?
Authors: DITTMAR AMY , THAKOR ANJAN 
Published: January 2007

ABSTRACTWe develop and test a new theory of security issuance that is consistent with the puzzling stylized fact that firms issue equity when their stock prices are high. The theory also generates new predictions. Our theory predicts that managers use equity to finance projects when they believe that investors' views about project payoffs are likely to be aligned with theirs, thus maximizing the likelihood of agreement with investors. Otherwise, they use debt. We find strong empirical support for our theory and document its incremental explanatory power over other security‐issuance theories such as market timing and time‐varying adverse selection.
Common Failings: How Corporate Defaults Are Correlated
Authors: DAS SANJIV R. , DUFFIE DARRELL , KAPADIA NIKUNJ , SAITA LEANDRO 
Published: January 2007

ABSTRACTWe test the doubly stochastic assumption under which firms' default times are correlated only as implied by the correlation of factors determining their default intensities. Using data on U.S. corporations from 1979 to 2004, this assumption is violated in the presence of contagion or “frailty” (unobservable explanatory variables that are correlated across firms). Our tests do not depend on the time‐series properties of default intensities. The data do not support the joint hypothesis of well‐specified default intensities and the doubly stochastic assumption. We find some evidence of default clustering exceeding that implied by the doubly stochastic model with the given intensities.
Lower Salaries and No Options? On the Optimal Structure of Executive Pay
Authors: DITTMANN INGOLF , MAUG ERNST 
Published: January 2007

ABSTRACTWe calibrate the standard principal–agent model with constant relative risk aversion and lognormal stock prices to a sample of 598 U.S. CEOs. We show that this model predicts that most CEOs should not hold any stock options. Instead, CEOs should have lower base salaries and receive additional shares in their companies; many would be required to purchase additional stock in their companies. These contracts would reduce average compensation costs by 20% while providing the same incentives and the same utility to CEOs. We conclude that the standard principal–agent model typically used in the literature cannot rationalize observed contracts.
Interest Rate Caps “Smile” Too! But Can the LIBOR Market Models Capture the Smile?
Authors: JARROW ROBERT , LI HAITAO , ZHAO FENG 
Published: January 2007

ABSTRACTUsing 3 years of interest rate caps price data, we provide a comprehensive documentation of volatility smiles in the caps market. To capture the volatility smiles, we develop a multifactor term structure model with stochastic volatility and jumps that yields a closed‐form formula for cap prices. We show that although a three‐factor stochastic volatility model can price at‐the‐money caps well, significant negative jumps in interest rates are needed to capture the smile. The volatility smile contains information that is not available using only at‐the‐money caps, and this information is important for understanding term structure models.
The Impact of Collateralization on Swap Rates
Authors: JOHANNES MICHAEL , SUNDARESAN SURESH 
Published: January 2007

ABSTRACTInterest rate swap pricing theory traditionally views swaps as a portfolio of forward contracts with net swap payments discounted at LIBOR rates. In practice, the use of marking‐to‐market and collateralization questions this view as they introduce intermediate cash flows and alter credit characteristics. We provide a swap valuation theory under marking‐to‐market and costly collateral and examine the theory's empirical implications. We find evidence consistent with costly collateral using two different approaches; the first uses single‐factor models and Eurodollar futures prices, and the second uses a formal term structure model and Treasury/swap data.
The Value of Embedded Real Options: Evidence from Consumer Automobile Lease Contracts
Authors: GIACCOTTO CARMELO , GOLDBERG GERSON M. , HEGDE SHANTARAM P. 
Published: January 2007

ABSTRACTUnder the common assumption of constant interest rates, we show that penalties for early termination of a lease are often structured in such a way that the cancellation option embedded in consumer automotive leases has little value. Furthermore, our estimates drawn from a sample of three popular car models over 1990 to 2000 indicate that the stand‐alone value of the lease‐end purchase option is, on average, about 16% of the market value of underlying used vehicles, or about $1,462 per contract. Finally, we examine the sensitivity of our option value estimates to model parameters and default risk.
Reconcilable Differences: Momentum Trading by Institutions
Authors: Sias Richard W. 
Published: January 2007

AbstractA growing literature evaluates the relation between lag returns and demand by institutional investors. Given that lag returns and institutional ownership are directly observable, it is surprising that previous tests yield dramatically different conclusions. This study examines differences across studies and finds that four factors account for these discrepancies: (1) value‐weighting versus equal‐weighting across stocks, (2) averaging versus aggregating over managers, (3) disagreement in the signs of measures of institutional demand, and (4) correlation between current capitalization and both lag returns and measures of institutional demand. Controlling for these factors, the results across different methods are remarkably uniform.
The U.S. Share of Trading Volume in Cross‐Listings: Evidence from Canadian Stocks
Authors: Sabherwal Sanjiv 
Published: January 2007

AbstractI analyze the firm‐specific determinants of the U.S. share of trading volume for 126 U.S.‐listed Canadian firms. I find that the U.S. share of volume is directly related to the mass of informed and liquidity traders in the United States relative to Canada, as proxied by relative analyst following, relative duration of listing, and the U.S. share of sales. Evidence also supports the market liquidity argument that the market with lower spreads and greater depths has greater volume. Finally, the U.S. share is directly related to the relative sensitivity of the stock's value to information in the United States.
Climate for Scandal: Corporate Environments that Contribute to Accounting Fraud
Authors: Crutchley Claire E. , Jensen Marlin R. H. , Marshall Beverly B. 
Published: January 2007

AbstractWe examine the governance characteristics, earnings quality, growth rates, dividend policy, and compensation structure of 97 firms recently under investigation by the Securities and Exchange Commission (SEC) for accounting fraud. Our results show that the corporate environment most likely to lead to an accounting scandal manifests significant growth and accounting practices that are already pushing the envelope of earnings smoothing. Firms operating in this environment seem more likely to tip over the edge into fraud if there are fewer outsiders on the audit committee and outside directors appear overcommitted.
Equity with Warrants in Private Placements
Authors: Marciukaityte Dalia , Pennathur Anita K. 
Published: January 2007

AbstractWe examine private equity with warrant (unit) placements and compare them with private equity placements. Firms making unit placements are smaller, younger, riskier, and characterized by higher information asymmetry than equity‐placing firms. Furthermore, unit‐placing firms experience good pre‐placement stock performance; however, their post‐placement performance is poor and worse than that of equity‐placing firms. We also find that very few of the placed warrants are in the money at expiration. Our results are consistent with the window of opportunity hypothesis and the theory that warrants are especially desirable to a clientele of overoptimistic investors.