bluuebunny/crossref_metadata_2025_split huggingface dataset:
Habituation to Pain in “Medication Overuse Headache”: A CO2 Laser‐Evoked Potential Study
Authors: Ferraro Diana , Vollono Catello , Miliucci Roberto , Virdis Daniela , De Armas Liala , Pazzaglia Costanza , Le Pera Domenica , Tarantino Samuela , Balestri Martina , Di Trapani Girolamo , Valeriani Massimiliano 
Published: April 2012

(Headache 2012;52:792‐807)Objective.— Our aim was to investigate CO2 laser‐evoked potential (LEP) habituation to experimental pain in a group of patients affected by medication‐overuse headache, with a history of episodic migraine becoming chronic, before and after treatment, consisting in acute medication withdrawal and a preventive treatment cycle.Background.— One of the main features of LEPs in migraineurs is a lower habituation to repetitive noxious stimuli during the interictal phase.Methods.— LEPs were recorded to stimulation of both the right hand and the right perioral region in 14 patients and in 14 healthy subjects. The habituation of both the N1 and the vertex N2/P2 components was assessed by measuring the LEP amplitude changes across 3 consecutive repetitions of 30 trials each.Results.— In the 8 patients who had clinically improved after treatment, the N2/P2 amplitude habituation was significantly higher after treatment than before treatment following both hand (F = 43.2, P < .0001) and face stimulation (F = 6.9, P = .01). In these patients, the N2/P2 amplitude habituation after treatment was not different from that obtained in healthy controls (P = .18 and P = .73 for hand and face stimulation, respectively). On the contrary, in the patients who did not improve, the N2/P2 amplitude still showed reduced habituation after both hand (F = 3.1, P = .08) and face (F = 0.7, P = .4) stimulation.Conclusion.— The deficient habituation of the vertex N2/P2 complex was partly restored after successful treatment of medication‐overuse headache, reflecting a modification in pain‐processing pathways.
In Vitro Evaluation of Shear Bond Strength and Mode of Failure of the Interface between an Indirect Composite Bonded to Fiber‐Reinforced Composite Substructures
Authors: Antonopoulou Athina , Papadopoulos Triantafillos , Hatzikyriakos Andreas 
Published: April 2012

AbstractPurpose: Failures of fixed partial dentures (FPDs) fabricated with fiber‐reinforced composites (FRCs) have been attributed to veneering fractures. The aim of the present study was to investigate the shear bond strength and mode of failure between an indirect composite and FRC substructures.Material and Methods: SR Adoro indirect composite was bonded to the following substructures: (a) flat surface made of unidirectional glass fibers (group A), (b) retentive sticks made of unidirectional glass fibers (group B), (c) flat surface made of fiber net (group C), (d) retentive sticks made of fiber net (group D), (e) nickel‐chromium dental alloy (control, group E). For every group, 13 specimens were fabricated. All specimens were hydrothermocycled (5000 cycles, 5°C/30sec, and 55°C/30sec). A bond test was performed in a testing machine at a 0.5 mm/min crosshead speed according to ISO 10477. The failure mode was determined by examination of the fractured surfaces under an optical microscope. Selected specimens were examined with scanning electron microscope and with energy dispersive spectroscopy for compositional determination. The morphology (flat‐sticks) and the type (unidirectional‐net) of fibers on the bond strength were estimated.Results: The mean shear bond strength was significantly different between groups E and A (p= 0.044), and groups A and B (p= 0.010). All FRC specimens showed cohesive failure. Group E showed predominantly adhesive failure. The bond strength was higher when sticks or fiber nets were used.Conclusions: Fiber nets and retentive sticks increase the shear bond strength between FRCs and indirect composite. Clinical implications: In FPDs, the morphology and type of FRC substructures might influence the shear bond strength between the FRC substructure and the indirect veneering composite. With the proper design of these substructures, the number of veneering fractures may be decreased.
Gaussian Estimation of Single‐Factor Continuous Time Models of The Term Structure of Interest Rates
Authors: NOWMAN K. B. 
Published: April 2012

ABSTRACTThis article presents the first application in finance of recently developed methods for the Gaussian estimation of continuous time dynamic models. A range of one factor continuous time models of the short‐term interest rate are estimated using a discrete time model and compared to a recent discrete approximation used by Chan, Karolyi, Longstaff, and Sanders (1992a, hereafter CKLS). Whereas the volatility of short‐term rates is highly sensitive to the level of rates in the United States, it is not in the United Kingdom.
Testing Market Efficiency: Evidence From The NFL Sports Betting Market
Authors: GRAY PHILIP K. , GRAY STEPHEN F. 
Published: April 2012

ABSTRACTThis article examines the efficiency of the National Football League (NFL) betting market. The standard ordinary least squares (OLS) regression methodology is replaced by a probit model. This circumvents potential econometric problems, and allows us to implement more sophisticated betting strategies where bets are placed only when there is a relatively high probability of success. In‐sample tests indicate that probit‐based betting strategies generate statistically significant profits. Whereas the profitability of a number of these betting strategies is confirmed by out‐of‐sample testing, there is some inconsistency among the remaining out‐of‐sample predictions. Our results also suggest that widely documented inefficiencies in this market tend to dissipate over time.
Measuring Mutual Fund Performance with Characteristic‐Based Benchmarks
Authors: DANIEL KENT , GRINBLATT MARK , TITMAN SHERIDAN , WERMERS RUSS 
Published: April 2012

ABSTRACTThis article develops and applies new measures of portfolio performance which use benchmarks based on the characteristics of stocks held by the portfolios that are evaluated. Specifically, the benchmarks are constructed from the returns of 125 passive portfolios that are matched with stocks held in the evaluated portfolio on the basis of the market capitalization, book‐to‐market, and prior‐year return characteristics of those stocks. Based on these benchmarks, “Characteristic Timing” and “Characteristic Selectivity” measures are developed that detect, respectively, whether portfolio managers successfully time their portfolio weightings on these characteristics and whether managers can select stocks that outperform the average stock having the same characteristics. We apply these measures to a new database of mutual fund holdings covering over 2500 equity funds from 1975 to 1994. Our results show that mutual funds, particularly aggressive‐growth funds, exhibit some selectivity ability, but that funds exhibit no characteristic timing ability.
Options on Leveraged Equity: Theory and Empirical Tests
Authors: TOFT KLAUS BJERRE , PRUCYK BRIAN 
Published: April 2012

ABSTRACTWe develop an option pricing model for calls and puts written on leveraged equity in an economy with corporate taxes and bankruptcy costs. The model explains implied Black‐Scholes volatility biases by relating them to the firm's structural characteristics such as leverage and debt covenants. We test the model by comparing predicted pricing biases with biases observed in a large cross‐section of firms with liquid exchange traded option contracts. Our empirical study detects leverage related pricing biases. The magnitudes of these biases correspond to those predicted by our model. We also find significant pricing biases for firms financed primarily by short‐term debt. This supports our model because short‐term debt introduces net‐worth hurdles similar to net‐worth covenants.
A Nonparametric Model of Term Structure Dynamics and the Market Price of Interest Rate Risk
Authors: STANTON RICHARD 
Published: April 2012

ABSTRACTThis article presents a technique for nonparametrically estimating continuous‐time diffusion processes that are observed at discrete intervals. We illustrate the methodology by using daily three and six month Treasury Bill data, from January 1965 to July 1995, to estimate the drift and diffusion of the short rate, and the market price of interest rate risk. While the estimated diffusion is similar to that estimated by Chan, Karolyi, Longstaff, and Sanders (1992), there is evidence of substantial nonlinearity in the drift. This is close to zero for low and medium interest rates, but mean reversion increases sharply at higher interest rates.
Special Repo Rates: An Empirical Analysis
Authors: JORDAN BRADFORD D. , JORDAN SUSAN D. 
Published: April 2012

ABSTRACTDuffie (1996) examines the theoretical impact of repo “specials” on the prices of Treasury securities and concludes that, all else the same, an issue on special will carry a higher price than an otherwise identical issue. We examine this hypothesis and find strong evidence in support of it. We also examine whether the liquidity premium associated with “on‐the‐run” issues is due to repo specialness and find evidence of a distinct effect. Finally, we investigate whether auction tightness and percentage awarded to dealers are related to subsequent specialness and find that both variables àre generally significant.
Speculation Duopoly with Agreement to Disagree: Can Overconfidence Survive the Market Test?
Authors: KYLE ALBERT S. , WANG F. ALBERT 
Published: April 2012

ABSTRACTIn a duopoly model of informed speculation, we show that overconfidence may strictly dominate rationality since an overconfident trader may not only generate higher expected profit and utility than his rational opponent, but also higher than if he were also rational. This occurs because overconfidence acts like a commitment device in a standard Cournot duopoly. As a result, for some parameter values the Nash equilibrium of a two‐fund game is a Prisoner's Dilemma in which both funds hire overconfident managers. Thus, overconfidence can persist and survive in the long run.
A New Look at the Monday Effect
Authors: WANG KO , LI YUMING , ERICKSON JOHN 
Published: April 2012

ABSTRACTIt is well documented that expected stock returns vary with the day‐of‐the‐week (the Monday or weekend effect). In this article we show that the well‐known Monday effect occurs primarily in the last two weeks (fourth and fifth weeks) of the month. In addition, the mean Monday return of the first three weeks of the month is not significantly different from zero. This result holds for most of the subperiods during the 1962–1993 sampling period and for various stock return indexes. The monthly effect reported by Ariel (1987) and Lakonishok and Smidt (1988) cannot fully explain this phenomenon.
Endogenous Borrowing Constraints With Incomplete Markets
Authors: ZHANG HAROLD H. 
Published: April 2012

ABSTRACTThis article develops ways to endogenize the borrowing constraints used in a class of computable incomplete markets models. We allow the constraints to depend on an investor's characteristics such as time preference, risk aversion, and income streams. The proposed constraint can be interpreted as a borrowing limit within which an investor has no incentive to default. Using a numerical algorithm, we find that for an array of structural parameters, the endogenous borrowing constraints can be much less stringent than the ad hoc borrowing constraints adopted by the existing studies.
The Limits of Arbitrage
Authors: Shleifer Andrei , Vishny Robert W. 
Published: April 2012

ABSTRACTTextbook arbitrage in financial markets requires no capital and entails no risk. In reality, almost all arbitrage requires capital, and is typically risky. Moreover, professional arbitrage is conducted by a relatively small number of highly specialized investors using other people's capital. Such professional arbitrage has a number of interesting implications for security pricing, including the possibility that arbitrage becomes ineffective in extreme circumstances, when prices diverge far from fundamental values. The model also suggests where anomalies in financial markets are likely to appear, and why arbitrage fails to eliminate them.
Internal Capital Markets and the Competition for Corporate Resources
Authors: STEIN JEREMY C. 
Published: April 2012

ABSTRACTThis article examines the role of corporate headquarters in allocating scarce resources to competing projects in an internal capital market. Unlike a bank, headquarters has control rights that enable it to engage in “winner‐picking”—the practice of actively shifting funds from one project to another. By doing a good job in the winner‐picking dimension, headquarters can create value even when it cannot help at all to relax overall firm‐wide credit constraints. The model implies that internal capital markets may sometimes function more efficiently when headquarters oversees a small and focused set of projects.
Quotes, Order Flow, and Price Discovery
Authors: BLUME MARSHALL E. , GOLDSTEIN MICHAEL A. 
Published: April 2012

ABSTRACTThe goal of this article is to examine the impact of 1975 Congressional mandate to integrate the trading of NYSE‐listed stocks. The conclusions are: most of the time, the New York Stock Exchange (NYSE) quote matches or determines the best displayed quote, and the NYSE is the most frequent initiator of quote changes. Non‐NYSE markets attract a significant portion of their volume when they are posting inferior bids or offers, indicating they obtain order flow for other reasons, such as “payment for order flow.” Yet, when a non‐NYSE market does post a better bid or offer, it does attract additional order flow.
Marketable Incentive Contracts and Capital Structure Relevance
Authors: GARVEY GERALD T. 
Published: April 2012

ABSTRACTThis article investigates the claim that debt finance can increase firm value by curtailing managers' access to “free cash flow.” We first show that incentive contracts that tie the managers' pay to stockholder wealth are often a superior solution to the free cash flow problem. We then consider the possibility that the manager can trade on secondary capital markets. Liquid secondary markets are shown to undermine management incentive schemes and, in many cases, to restore the value of debt finance in controlling the free cash flow problem.
Strategic Debt Service
Authors: MELLA‐BARRAL PIERRE , PERRAUDIN WILLIAM 
Published: April 2012

ABSTRACTWhen firms experience financial distress, equity holders may act strategically, forcing concessions from debtholders and paying less than the originally‐contracted interest payments. This article incorporates strategic debt service in a standard, continuous time asset pricing model, developing simple closed‐form expressions for debt and equity values. We find that strategic debt service can account for a substantial proportion of the premium on risky corporate debt. We analyze the efficiency implications of strategic debt service, showing that it can eliminate both direct bankruptcy costs and agency costs of debt.
Assessing Specification Errors in Stochastic Discount Factor Models
Authors: HANSEN LARS PETER , JAGANNATHAN RAVI 
Published: April 2012

ABSTRACTIn this article we develop alternative ways to compare asset pricing models when it is understood that their implied stochastic discount factors do not price all portfolios correctly. Unlike comparisons based on statistics associated with null hypotheses that models are correct, our measures of model performance do not reward variability of discount factor proxies. One of our measures is designed to exploit fully the implications of arbitrage‐free pricing of derivative claims. We demonstrate empirically the usefulness of our methods in assessing some alternative stochastic factor models that have been proposed in asset pricing literature.
On Stock Market Returns and Monetary Policy
Authors: THORBECKE WILLEM 
Published: April 2012

ABSTRACTFinancial economists have long debated whether monetary policy is neutral. This article addresses this question by examining how stock return data respond to monetary policy shocks. Monetary policy is measured by innovations in the federal funds rate and nonborrowed reserves, by narrative indicators, and by an event study of Federal Reserve policy changes. In every case the evidence indicates that expansionary policy increases ex‐post stock returns. Results from estimating a multi‐factor model also indicate that exposure to monetary policy increases an asset's ex‐ante return.
Equilibrium Valuation of Foreign Exchange Claims
Authors: BAKSHI GURDIP S. , CHEN ZHIWU 
Published: April 2012

ABSTRACTThis article studies the equilibrium valuation of foreign exchange contingent claims. Within a continuous‐time Lucas (1982) two‐country model, exchange rates, interest rates and, in particular, factor risk prices are all endogenously and jointly determined. This guarantees the internal consistency of these price processes with a general equilibrium. In the same model, closed‐form valuation formulas are presented for currency options and currency futures options. Common to these formulas is that stochastic volatility and stochastic interest rates are admitted. Hedge ratios and other comparative statics are also provided analytically. It is shown that most existing currency option models are included as special cases.
Good News for Value Stocks: Further Evidence on Market Efficiency
Authors: PORTA RAFAEL LA , LAKONISHOK JOSEF , SHLEIFER ANDREI , VISHNY ROBERT 
Published: April 2012

ABSTRACTThis article examines the hypothesis that the superior return to so‐called value stocks is the result of expectational errors made by investors. We study stock price reactions around earnings announcements for value and glamour stocks over a 5‐year period after portfolio formation. The announcement returns suggest that a significant portion of the return difference between value and glamour stocks is attributable to earnings surprises that are systematically more positive for value stocks. The evidence is inconsistent with a risk‐based explanation for the return differential.
Predictors of steal syndrome in hemodialysis patients
Authors: Rocha Ana , Silva Fernanda , Queirós José , Malheiro Jorge , Cabrita António 
Published: April 2012

AbstractSteal syndrome is a feared complication of dialysis vascular access in a population becoming older and frailer. The aim of this study was to determine the predictor factors of steal syndrome. All proximal arteriovenous fistulas (AVFs), patent at day 30, inserted between January 2008 and December 2009 were studied. Data on age, gender, diabetes mellitus (DM) status, presence of coronary or peripheral artery disease, date of initiation of renal replacement therapy, date of access construction, localization, type of anastomosis, previous interventions, and outcome for AVF and patients were analyzed. There were 324 AVFs placed into 309 individual patients. The mean age was 66.7 ± 15.3 years, and the majority (53.7%) of the patients was male. Mean follow‐up of all 324 fistulas was 18.6 ± 8.5 months. During follow‐up, steal syndrome occurred in 26 (8%) of the AVFs. Univariate analysis revealed correlations between steal syndrome and DM (P = 0.002), brachiomedian fistulas (P = 0.016), and side‐to‐side (STS) anastomosis (P = 0.003). However, in multivariate analysis, the presence of DM, STS anastomosis, and female gender were found to be the independent risk factors. The strongest predictive factor was DM (odds ratio: 6.7; 95% confidence interval: 2.5–17.9). Being diabetic is the factor most predictive of having steal syndrome. In diabetic women, with a proximal access, it seems preferable to construct fistulas with end‐to‐side anastomosis to minimize the risk.
Capacitance Enhancement of Doped Barium Titanate Dielectrics and Multilayer Ceramic Capacitors by a Post‐Sintering Thermo‐Mechanical Treatment
Authors: Guillon Olivier , Chang Jaemyung , Schaab Silke , Kang Suk‐Joong L. 
Published: April 2012

High capacitance of miniaturized multilayer ceramic capacitors (MLCCs) is of great interest from both academic and industrial points of view. Because of the limited number of suitable materials (possessing high permittivity and low losses), the capacitance of MLCCs may be enhanced by modifying the capacitor geometry (i.e., by reducing the layer thicknesses or increasing the internal electrodes‧ area) and by optimizing the thermal schedule during processing. In this study, we describe a post‐sintering thermo‐mechanical treatment to increase the capacitance of dielectrics and MLCCs. A uniaxial mechanical load was applied during the cooling from either below or above the Curie temperature to room temperature. After load release, the permittivity permanently increased at room temperature by ~8%–11% after a stress of 20 MPa had been applied. The configuration of the ferroelectric domains and the residual stress may be responsible for this improvement.
Bone healing around titanium implants in two rat colitis models
Authors: Kuchler Ulrike , Luvizuto Eloa R. , Muñoz Fernando , Hofbauer Julia , Watzek Georg , Gruber Reinhard 
Published: April 2012

AbstractObjectiveCrohn's disease is a chronic inflammatory process that has recently been associated with a higher risk of early implant failure. Herein we provide information on the impact of colitis on peri‐implant bone formation using preclinical models of chemically induced colitis.MethodsColitis was induced by intrarectal instillation of 2,4,6‐trinitro‐benzene‐sulfonic‐acid (TNBS). Colitis was also induced by feeding rats dextran‐sodium‐sulfate (DSS) in drinking water. One week after disease induction, titanium miniscrews were inserted into the tibia. Four weeks after implantation, peri‐implant bone volume per tissue volume (BV/TV) and bone‐to‐implant contacts (BIC) were determined by histomorphometric analysis.ResultsCortical histomorphometric parameters were similar in the control (n = 10), DSS (n = 10) and TNBS (n = 8) groups. Cortical BV/TV was 92.2 ± 3.7%, 92.0 ± 3.0% and 92.6 ± 2.7%. Cortical BIC was 81.3 ± 8.8%, 83.2 ± 8.4% and 84.0 ± 7.0%, respectively. No significant differences were observed when comparing the medullary BV/TV and BIC (19.5 ± 6.4%, 16.2 ± 5.6% and 15.4 ± 9.0%) and (48.8 ± 12.9%, 49.2 ± 6.2 and 41.9 ± 11.7%), respectively. Successful induction of colitis was confirmed by loss of body weight and colon morphology.ConclusionsThe results suggest bone regeneration around implants is not impaired in chemically induced colitis models. Considering that Crohn's disease can affect any part of the gastrointestinal tract including the mouth, our model only partially reflects the clinical situation.