bluuebunny/crossref_metadata_2025 huggingface dataset:
Bark beetle‐mediated fungal infections of susceptible trees induce resistance to subsequent infections in a dose dependent manner
Authors: Erbilgin Nadir , Gordon Thomas R. , Wood David L. , Storer Andrew J.
Published: July 2009

1 Experiments were conducted to determine whether propagule loads on the twig beetlesPityophthorus setosusandPityophthorus carmeli(Coleoptera: Scolytidae) influence the pathogen infection of the host tree in the Monterey pine‐Fusarium circinatumsystem.

2 On an average,F. circinatumwas isolated from 2.6% and 3.3% of trappedP. setosusandP. carmeli, respectively, although the isolation percentages varied over the season, being highest in the spring and lowest in late summer and fall for both species. Mean pathogen load was 13.4 and 22.6 propagules per beetle, onP. setosusandP. carmeli, respectively, and decreased from May to November for both species. The pathogen was also isolated from approximately 55% of both beetle species that emerged from infected branches. Mean propagule load on emergedP. setosusandP. carmeliwas 39 and 66.5, respectively.

3 On the basis of these data, beetle species were treated with one of three propagule loads (low, medium, high) and caged onto live branches to determine whether they could transmit the pathogen. At all propagule loads, both species transmitted the pathogen, and transmission percentage and lesion length, a measure of tree susceptibility, were positively correlated with propagule load.

4 To investigate further whether the previous transmission by beetles could affect response of the same trees to subsequent infection withF. circinatum, different branches were inoculated on the same trees used in the transmission study, and lesion lengths were measured. Lesion lengths were lower on trees that had been previously exposed to beetles treated with high or medium propagule loads than on trees that had previously been exposed to beetles treated with low propagule loads. This suggests that the initial infection by beetles carrying high or medium propagule loads induced resistance to subsequent infections of the host, whereas infections caused by beetles with low propagule loads did not.
Adaptation of Escherichi coli to elevated temperatures involves a change in stability of heat shock gene transcripts
Authors: Shenhar Yotam , Rasouly Aviram , Biran Dvora , Ron Eliora Z.
Published: July 2009

Bacteria respond to shift‐up in temperature by activating the heat shock response – induction of a large number of heat shock genes. This response is essential for adaptation to the higher temperature and for acquiring thermotolerance. One unique feature of the heat shock response is its transient nature – shortly after the induction, the rate of synthesis of heat shock proteins decreases, even if the temperature remains high. Here we show that this shutoff is due to a decrease in the transcript stability of heat shock genes. We further show that the modulation of stability of mRNAs of heat shock genes is maintained by the cold shock protein C – CspC – previously shown to affect transcript stability of specific genes. Upon shifts to higher temperatures the level of this protein decreases due to proteolysis and aggregation, leading to a reduced stability of mRNAs of heat shock genes. The temperature‐dependent modulation of transcript stability of heat shock genes constitutes a novel control of the bacterial response to temperature changes.
PURCHASING POWER PARITY IN LESS‐DEVELOPED AND TRANSITION ECONOMIES: A REVIEW PAPER
Authors: Bahmani‐Oskooee Mohsen , Hegerty Scott W.
Published: July 2009

AbstractThe concept of purchasing power parity (PPP) has been the subject of numerous studies, many of which have been unable to prove conclusively this core principle of international finance. Although industrialized countries have received most of the attention, studies that focus on less‐developed and transition economies have also attained mixed results. This study surveys trends in this branch of the literature, highlighting the econometric advances that have sought to solve this puzzle, while pointing out that more needs to be done to address the reasons that might cause PPP not to hold.
CAPITALIZATION OF GOVERNMENT SUPPORT IN AGRICULTURAL LAND PRICES: WHAT DO WE KNOW?
Authors: Latruffe Laure , Le Mouël Chantal
Published: July 2009

Abstract The objective of this paper is to provide an overview of existing literature, both theoretically and empirically, on the extent to which agricultural subsidies do translate into higher land values and rents and finally benefit landowners instead of agricultural producers. Our review shows that agricultural support policy instruments contribute to increasing the rental price of farmland, and that the extent of this increase closely depends on the level of the supply price elasticity of farmland relative to those of other factors/inputs on the one hand, and on the range of the possibilities of factor/input substitution in agricultural production on the other hand. The empirical literature shows that land prices and rents have in general a significant positive and inelastic response to government support. Such inelastic response is thought to reflect the uncertain future of the farm programmes. And in general, studies have indicated that land prices are more responsive to government‐based returns than to market‐based returns.
CASE‐BASED REASONING FOR MANAGING NONCOMPLIANCE WITH CLINICAL GUIDELINES
Authors: Montani Stefania
Published: July 2009

Despite the recognized advantages that can be obtained in clinical practice when following clinical guidelines (GL), situations of noncompliance with them may emerge. Keeping track of such deviations from the default GL execution, and documenting the physician's motivations, would clearly be an added value. Moreover, repeated alterations of GL actions (or flow) may highlight the need for an adaptation of the GL itself to the local reality, or may even indicate an improper or weak initial GL definition.

In this article, we propose an approach for managing noncompliance with GL, based on the case‐based reasoning methodology. In front of a new noncompliance case, our tool allows the physician to retrieve past situations similar to the current one, and to decide whether to reapply the same GL modifications adopted in them. Moreover, the tool is able to learn indications from the ground noncompliance cases that can be deployed for local adaptation, and possibly, for suggesting more formal GL revisions to be carried out by a committee of expert physicians.
PROTOTYPICAL CASES FOR RETRIEVAL, REUSE, AND KNOWLEDGE MAINTENANCE IN BIOMEDICAL CASE‐BASED REASONING
Authors: Bichindaritz Isabelle
Published: July 2009

Representing biomedical knowledge is an essential task in biomedical informatics intelligent systems. Case‐based reasoning (CBR) holds the promise to represent contextual knowledge in a way that was not possible before with traditional knowledge‐based methods. One main issue in biomedical CBR is dealing with the rate of generation of new knowledge in biomedical fields, which often makes the content of a case base partially obsolete. This article proposes to make use of the concept of prototypical case to ensure that a CBR system would keep update with current research advances in the biomedical field. Prototypical cases have served various purposes in biomedical CBR systems, among which to organize and structure the memory, to guide the retrieval as well as the reuse of cases, and to serve as bootstrapping a CBR system memory when real cases are not available in sufficient quantity and/or quality. This paper emphasizes the different roles prototypical cases can play in CBR systems, and presents knowledge maintenance as a very important novel role for these prototypical cases.
A CBR‐BASED, CLOSED‐LOOP ARCHITECTURE FOR TEMPORAL ABSTRACTIONS CONFIGURATION
Authors: Montani Stefania , Bottrighi Alessio , Leonardi Giorgio , Portinale Luigi
Published: July 2009

In the hemodialysis domain, we are implementing a case‐based, closed‐loop architecture aimed at configuring temporal abstractions (TA), which will be applied to time series data. The advantage of a case‐based approach is the one of “quickly” obtaining a suitable TA parameter configuration, simply by looking at the most similar already configured case, where configured cases are indexed by means of contextual information. The retrieved configuration, together with the time series data, is then used as an input to a TA processing module, able to provide a set of qualitative states, trends, and significant combinations of both as an output. TA processing results can finally be evaluated, possibly leading to a (human‐supervized) reorganization/revision of the case base content, to ameliorate future TA configuration sessions—thus closing the loop. The work is being integrated with RHENE, a system for case‐based retrieval in hemodialysis, able to work both on raw time series data and on preprocessed (by means of TA) ones.
The loss of grammatical gender in Cappadocian Greek1
Authors: Karatsareas Petros
Published: July 2009

Cappadocian Greek is an extreme case of language change and dialectal variation among the Modern Greek dialects in having lost the tripartite grammatical gender distinction into masculine, feminine and neuter nominals, a distinction operative in Greek since its earliest recorded stages. In this paper, I argue that this linguistic innovation should not be viewed exclusively as the result of language contact with Turkish, as is most commonly assumed in the literature, but rather as the result of a series of language‐internal analogical levellings of gender mismatches in polydefinite constructions, a process most probably accelerated by language contact but certainly not triggered by it.
How Do US Economic Sanctions Affect EU's Trade with Target Countries?
Authors: Yang Jiawen , Askari Hossein , Forrer John , Zhu Lili
Published: July 2009

We investigate the impact of US economic sanctions on EU's trade using a panel data approach expressed in a two‐level framework. Both multilateral and unilateral sanctions involving the US and the EU have a negative impact on EU trade (total, imports and exports). We argue that unilateral sanctions, if extensive in nature, would have a depressing impact on target countries’ trade, especially in the stage after sanctions have been imposed. Over time, both multilateral and unilateral sanctions lead to an increase in a target country's exports to the EU, lending support to the third‐country effect of sanctions.
A Desire to Return to the Country of Birth as a Function of Language Preference: An Empirical Study with Iranian Immigrants in the United States
Authors: Hojat Mohammadreza , Foroughi Danesh , Mahmoudi Homa , Holakouee Farhang
Published: July 2009

It was hypothesized that bilingual Iranian immigrants in the United States who prefer to use the Persian language, compared to Iranians who prefer to use English, would be more likely to express a desire to return to Iran to live. Participants were 292 bilingual Iranian immigrants in the United States (128 men, 164 women) who completed a questionnaire with a similar content, prepared in Persian on one side and in English on the other side. Participants were given the option to either complete the Persian or English version of the questionnaire. Results confirmed the research hypothesis suggesting that the immigrants’ preference in using their native language serves as a “pull” factor that increases the probability of a desire to return to the country of birth. It was also found that women and younger respondents were less likely to express a desire to return to Iran. Level of education, marital status, years of living in the United States, and attitudes toward marriage and the family did not predict such a desire. Implications for acculturation research and for counseling culturally diverse clients are discussed. Policy implications to attract immigrants back to their country of birth were also discussed.
Were In‐Process Research and Development Charges Too Aggressive?
Authors: Dowdell Thomas D. , Lim Steve C. , Press Eric
Published: July 2009

Abstract:  Prior research documents that US firms write off large in‐process research and development charges (IPRD) for acquisitions, possibly overstating the current period expense to inflate future earnings. Consequently, in 1998, the US Securities and Exchange Commission (SEC) began scrutinizing IPRD charges. We use pre‐acquisition R&D expenses of 144 target firms as a benchmark for assessing whether IPRD charges are appropriate. Overall, the results suggest that most firms during our sample period were not overly aggressive in expensing IPRD–especially for acquisitions subsequent to the SEC's scrutiny. The results also indicate that the SEC's intervention reduced the frequency of overstated IPRD charges.
Changes to Income Trust Taxation in Canada: Investor Reaction and Dividend Clientele Theory
Authors: Elayan Fayez A. , Li Jingyu , Donnelly Maureen E. , Young Allister W.
Published: July 2009

Abstract:  This paper explores the relationship between tax‐induced dividend clientele theory and the recent changes to the taxation of income trusts in Canada. On October 31, 2006, the Canadian government announced the Tax Fairness Plan (TFP) calling for the elimination of the considerable tax advantage enjoyed by income trusts. Generally, distributions from income trusts are now taxed at rates comparable to those imposed on corporate dividends. We examine market reaction to the TFP to address three issues: first, whether the valuation effect of a dividend tax increase is consistent with the traditional or the new view of dividend taxation; secondly, whether the market reaction to tax increases has a differential impact on firm value that is related to the tax preferences of taxable, tax‐exempt, and foreign investor tax clienteles; and thirdly, whether firms change their dividend policies in response to the preference of institutional investors (tax‐based dividend policy effect) or whether institutional investors are sorting themselves across firms based on their dividend policies (investor sorting effect). Our results provide strong evidence as follows. First, the valuation effect in reaction to the TFP announcement is consistent with the traditional view of dividend taxation – i.e. that taxes on dividends reduce the net return to investors, increase the firm's cost of capital and lower the firm's ability to access capital markets, thereby discouraging investment and savings. Secondly, we saw that trusts with a larger percentage of their units held by tax‐exempt, low‐tax, and foreign investors had a higher decline in value when compared with trusts held mostly by ordinary taxable investors. These results support dividend tax clientele theory. Finally, we observed changes in institutional investor clienteles consistent with the investor sorting effect.
Ontogeny of the tessellated skeleton: insight from the skeletal growth of the round stingray Urobatis halleri
Authors: Dean Mason N. , Mull Chris G. , Gorb Stanislav N. , Summers Adam P.
Published: July 2009

The majority of the skeleton of elasmobranch fishes (sharks, rays and relatives) is tessellated: uncalcified cartilage is overlain by a superficial rind of abutting, mineralized, hexagonal blocks called tesserae. We employed a diversity of imaging techniques on an ontogenetic series of jaw samples to investigate the development of the tessellated skeleton in a stingray (Urobatis halleri). We compared these data with the cellular changes that characterize cartilage calcification in bony skeletons. Skeletal growth is characterized by the appearance of tesserae as well as changes in chondrocyte shape, arrangement and density. Yolk sac embryos (35–56 mm disc width, DW) have untessellated lower jaw tissue wrapped in perichondrium and densely packed with chondrocytes. Chondrocyte density decreases dramatically after yolk sac absorption (histotroph stage: 57–80 mm DW) until the formation of tesserae, which are first visible using our techniques as thin (~60 µm), sub‐perichondral plaques. During the histotroph stage, flattened chondrocytes align parallel to the perichondrium at the tissue periphery, where we believe they are incorporated into developing tesserae to form the cell‐rich laminae observed within tesserae; in older animals peripheral cells in the uncalcified phase are rounder and less uniformly oriented. By parturition (~75 mm DW), cell density and the number of adjoining chondrocyte pairs (an indicator of cell division) have dropped to less than a third of their initial values; these remain low and tesserae continue to grow in size. The tessellated skeleton is a simple solution to the conundrum of growth in an endoskeleton with external mineralization and no remodeling. Although we see parallels with endochondral ossification (e.g. chondrocytes decreasing in density with age), the lack of chondrocyte hypertrophy and the fact that mineralization is sub‐perichondral (not the case in mammalian cartilage) suggest that the similarities end there.
Mechanical constraints on the functional morphology of the gibbon hind limb
Authors: Channon Anthony J. , Günther Michael M. , Crompton Robin H. , Vereecke Evie E.
Published: July 2009

Gibbons utilize a number of locomotor modes in the wild, including bipedalism, leaping and, most of all, brachiation. Each locomotor mode puts specific constraints on the morphology of the animal; in some cases these may be complementary, whereas in others they may conflict. Despite several studies of the locomotor biomechanics of gibbons, very little is known about the musculoskeletal architecture of the limbs. In this study, we present quantitative anatomical data of the hind limb for four species of gibbon (Hylobates lar, H. moloch, H. pileatus and Symphalangus syndactylus). Muscle mass and fascicle lengths were obtained from all of the major hind limb muscles and the physiological cross‐sectional area was calculated and scaled to remove the effect of body size. The results clearly indicate that, for all of the species studied, the major hip, knee and ankle extensors are short‐fascicled and pennate. The major hip and knee flexors, however, are long‐fascicled, parallel muscles with relatively small physiological cross‐sectional areas. We hypothesize that the short‐fascicled muscles could be coupled with a power‐amplifying mechanism and are predominantly useful in leaping. The long‐fascicled knee and hip flexors are adapted for a wide range of joint postures and can play a role in flexing the legs during brachiation.
Quantification of mitochondrial DNA mutation load
Authors: Greaves Laura C. , Beadle Nina E. , Taylor Geoffrey A. , Commane Daniel , Mathers John C. , Khrapko Konstantin , Turnbull Doug M.
Published: July 2009

Mitochondrial DNA (mtDNA) mutations are an important cause of genetic disease and have been proposed to play a role in the ageing process. Quantification of total mtDNA mutation load in ageing tissues is difficult as mutational events are rare in a background of wild‐type molecules, and detection of individual mutated molecules is beyond the sensitivity of most sequencing based techniques. The methods currently most commonly used to document the incidence of mtDNA point mutations in ageing include post‐PCR cloning, single‐molecule PCR and the random mutation capture assay. The mtDNA mutation load obtained by these different techniques varies by orders of magnitude, but direct comparison of the three techniques on the same ageing human tissue has not been performed. We assess the procedures and practicalities involved in each of these three assays and discuss the results obtained by investigation of mutation loads in colonic mucosal biopsies from ten human subjects.
PROVENANCE OF MARBLES FROM NAXOS BASED ON MICROSTRUCTURAL AND GEOCHEMICAL CHARACTERIZATION
Authors: EBERT A. , GNOS E. , RAMSEYER K. , SPANDLER C. , FLEITMANN D. , BITZIOS D. , DECROUEZ D.
Published: July 2009

A detailed quantitative microstructural study coupled with cathodoluminescence and geochemical analyses on marbles from Naxos demonstrates that the analysis of microstructures is the most sensitive method to define the origin of marbles within, and between, different regions. Microstructure examination can only be used as an accurate provenance tool if a correction for the second‐phase content is considered. If second phases are not considered, a large spread of different microstructures occurs within sample sites, making a separation between neighbouring outcrops difficult or impossible. Moreover, this study shows that the origin of a marble is defined more precisely if the microstructural observations are coupled with cathodoluminescence data.
Bioactivity as an Options Value of Sea Cucumbers in the Egyptian Red Sea
Authors: LAWRENCE A. J. , AFIFI R. , AHMED M. , KHALIFA S. , PAGET T.
Published: July 2009

Abstract:  The utility of a species can be divided into its direct, indirect, and options values. In the marine environment, direct consumptive values predominate and often lead to overexploitation at the expense of significant options values derived through bioprospecting for natural products. We surveyed the waters of the Egyptian Red Sea coast (Gulf of Aqaba [north] and the Red Sea [south]) for species of sea cucumbers and analyzed extracts from species for a range of bioactivities with potential biomedical applications. All habitat types were surveyed within these regions. We found 22 species of sea cucumber of which two, Holothuria fuscogilva and Holothuria flavomaculata, were recorded in Egypt for the first time. Although none of the species identified were unique to the Gulf of Aqaba, 10 species were only found in the Red Sea sector. Bioassay results showed that although no species had antibacterial activity, most extracts exhibited activity against Candida and Leishmania but were most active against a LoVo mammalian carcinoma cell line. Our most significant finding was the intraspecific variation in bioactivity in individuals collected from different habitat types and sectors of the coast. This variation may reflect the effect of environment on secondary metabolite production or may indicate significant genetic diversity between populations within a species. Our results indicate a potentially significant options value to sea cucumbers through bioprospecting. Given the importance of economic development in countries such as Egypt and the perceived low conservation value of invertebrates such as sea cucumbers, the linking of these factors to conservation is vital for the maintenance and sustainable exploitation of these animals.
Transfusion of stored red blood cells adhere in the rat microvasculature
Authors: Chin‐Yee Ian H. , Gray‐Statchuk Leslie , Milkovich Stephanie , Ellis Christopher G.
Published: July 2009

BACKGROUND: Ex vivo storage of red blood cells (RBCS) for transfusions is associated with a “storage lesion,” which decreases RBC deformability and increases RBC adhesiveness to vascular endothelium. This may impair microcirculatory flow with deleterious effects on oxygen delivery after transfusion. Previous studies have shown that human RBCs adhere to endothelial monolayers in vitro with prolonged storage and is reduced by prestorage leukoreduction (LR). The objective of this study was to determine whether duration of RBC storage and LR influence RBC adhesion in vivo in capillaries.

STUDY DESIGN AND METHODS: Rat RBCs were collected and stored in CPDA‐1 under standard blood bank conditions. Three RBC products were compared: 1) fresh RBCs, less than 24 hours of storage (n = 6); 2) nonleukoreduced (NLR) RBCs stored for 7 days (n = 6); and 3) prestorage LR RBCs stored for 7 days (n = 6). RBCs were labeled with fluorescein isothiocyanate (FITC) 24 hours before transfusion and reinjected in an isovolemic manner into healthy rats. The FITC‐labeled RBCs were visualized in the extensor digitorum longus muscle using intravital video microscopy (20× magnification). The number of RBCs adherent in capillaries was counted 1 hour after transfusion in 10 random fields and the median values were compared with one‐way analysis of variance.

RESULTS: Stored RBCs showed increased levels of adherence in capillaries compared to their fresh counterparts (p < 0.05). Prestorage LR decreased RBC adherence to levels equivalent to those of fresh RBCs (p < 0.05 for stored LR vs. stored NLR).

CONCLUSION: Rat RBCs stored under conditions that closely mimicked clinical transfusion adhere in capillaries. The decreased RBC adherence with LR suggest a direct effect of white blood cells or their byproducts on RBC deformability and/or adhesiveness to microvascular endothelium. Further study will examine the mechanism of adherence and the impact it has on microcirculatory flow and oxygen delivery in the critically ill host.
Length of storage and in vitro immunomodulation induced by prestorage leukoreduced red blood cells
Authors: Karam Oliver , Tucci Marisa , Toledano Baruch J. , Robitaille Nancy , Cousineau Jocelyne , Thibault Louis , Lacroix Jacques , Le Deist Françoise
Published: July 2009

BACKGROUND: The relationship between length of storage of red blood cell (RBC) units and biochemical changes has been well studied, but little is known about the progression of cellular immunomodulative properties in blood recipients. This study aims to quantify in vitro T‐cell activation and cytokine release by white blood cells, after incubation with supernatants from leukoreduced RBCs.

STUDY DESIGN AND METHODS: Whole blood cultures were incubated with supernatant from five leukoreduced RBC units stored for 1, 6, 10, 15, 24, and 42 days. Supernatant‐induced T‐cell activation was evaluated by quantifying CD25 expression. Supernatant‐induced cytokine production was determined by measuring interleukin (IL)‐6, IL‐10, and tumor necrosis factor (TNF)‐α levels.

RESULTS: No cytokines were detected in RBC supernatants even after 42 days of storage. However, IL‐6 levels in whole blood culture increased significantly when incubated with supernatant from RBC units stored for 1, 6, and 15 days, by factors of 1.7 ± 0.3, 1.7 ± 0.3, and 1.4 ± 0.3, respectively. TNF‐α levels were significantly decreased on Days 24 and 42 of storage by factors of 0.50 ± 0.42 and 0.33 ± 0.21, respectively. IL‐10 levels were significantly increased on Days 1 and 42 of storage by factors of 2.3 ± 1.3 and 3.2 ± 2.8, respectively. After an initial increase in IL‐6 and TNF‐α production, there was a significant linear decrease in their levels measured from units stored for longer times. No significant changes in CD25 expression were observed over time.

CONCLUSION: Although no cytokines were measured in the supernatants from leukoreduced RBCs, these supernatants exhibited variable immunomodulatory effects related to their length of storage.
Voting Transparency in a Monetary Union
Authors: GERSBACH HANS , HAHN VOLKER
Published: July 2009

We examine whether the monetary policy committee of a monetary union should publish its voting records when members are appointed by national politicians. We show that the publication of voting records lowers overall welfare. This finding also holds for arbitrary levels of private benefits from holding office and if governments incur costs when replacing committee members. High private benefits of committee members always lower overall welfare, as they induce nonpartisan members to care more about being reappointed than about beneficial policy outcomes. Nonrenewable but long terms for national committee members and delegating the appointment of all committee members to a union‐wide authority would be desirable.
Payments Settlement: Tiering in Private and Public Systems
Authors: KAHN CHARLES M. , ROBERDS WILLIAM
Published: July 2009

What are the benefits provided by a payment system? What are the trade‐offs in public versus private payment systems and in restricted versus open payments arrangements? Modern payment systems encompass a variety of institutional designs with varying degrees of counterparty protection. We develop a framework that allows for an examination and comparison of payment systems, and specification of conditions leading to their adoption. We relate these conditions to the design of present large‐value payment systems (Fedwire, CHIPS, TARGET, etc.).
Optimal Monetary Policy with an Uncertain Cost Channel
Authors: TILLMANN PETER
Published: July 2009

The cost channel of monetary transmission describes a supply‐side effect of interest rates on firms' costs. Previous research has found this effect to vary, both over time and across countries. Moreover, the cyclical nature of financial frictions is likely to amplify the cost channel. This paper derives optimal monetary policy in the presence of uncertainty about the true size of the cost channel. In a min–max approach, the central bank derives an optimal policy plan to be implemented by a Taylor rule. It is shown that uncertainty about the cost channel leads to an attenuated interest rate setting behavior. In this respect, the Brainard (1967) principle of cautious policy in the face of uncertainty continues to hold in both a Bayesian and a min–max framework.
Role of Collateral and Personal Guarantees in Relationship Lending: Evidence from Japan's SME Loan Market
Authors: ONO ARITO , UESUGI IICHIRO
Published: July 2009

This paper investigates the determinants of the use of collateral and personal guarantees in Japan's SME loan market. We find that firms' riskiness does not have a significant effect on the likelihood that collateral is used. We find, however, that main banks whose claims are collateralized monitor borrowers more intensively and that borrowers who have a long‐term relationship with their main banks are more likely to pledge collateral. These findings are consistent with the theory that the use of collateral is effective in raising the bank's seniority and enhances its screening and monitoring. This incentive effect for the bank becomes tenuous for personal guarantees.
The Global Side of the Investment‐Saving Puzzle
Authors: BYRNE JOSEPH P. , FAZIO GIORGIO , FIESS NORBERT
Published: July 2009

In this paper, we reexamine the long‐standing and puzzling correlation between national saving and investment in industrial countries. We apply an econometric methodology that allows us to separate idiosyncratic correlation at the country level from correlation at the global level. In a major break with the existing literature, we find no evidence of a long‐run relationship in the idiosyncratic components of saving and investment. We also find that the global components in saving and investments commove, indicating that they react to shocks of a global nature.
Modeling and Management of Nonlinear Dependencies–Copulas in Dynamic Financial Analysis
Authors: Eling Martin , Toplek Denis
Published: July 2009

Abstract

We study the influence of nonlinear dependencies on a non‐life insurer's risk and return profile. To achieve this, we integrate several copula models in a dynamic financial analysis framework and conduct numerical tests. We also test risk management strategies in response to adverse outcomes. Nonlinear dependencies have a crucial influence on the insurer's risk profile that can hardly be affected by the analyzed management strategies. We find large differences in risk assessment for the ruin probability and for the expected policyholder deficit. This has important implications for insurers, regulators, and rating agencies that use these measures as a foundation for internal risk models, capital standards, and ratings.
Presidential Address: Sophisticated Investors and Market Efficiency
Authors: STEIN JEREMY C.
Published: July 2009

Stock‐market trading is increasingly dominated by sophisticated professionals, as opposed to individual investors. Will this trend ultimately lead to greater market efficiency? I consider two complicating factors. The first is crowding—the fact that, for a wide range of “unanchored” strategies, an arbitrageur cannot know how many of his peers are simultaneously entering the same trade. The second is leverage—when an arbitrageur chooses a privately optimal leverage ratio, he may create a fire‐sale externality that raises the likelihood of a severe crash. In some cases, capital regulation may be helpful in dealing with the latter problem.
Predictive Systems: Living with Imperfect Predictors
Authors: PÁSTOR ĽUBOŠ , STAMBAUGH ROBERT F.
Published: July 2009

We develop a framework for estimating expected returns—a predictive system—that allows predictors to be imperfectly correlated with the conditional expected return. When predictors are imperfect, the estimated expected return depends on past returns in a manner that hinges on the correlation between unexpected returns and innovations in expected returns. We find empirically that prior beliefs about this correlation, which is most likely negative, substantially affect estimates of expected returns as well as various inferences about predictability, including assessments of a predictor's usefulness. Compared to standard predictive regressions, predictive systems deliver different expected returns with higher estimated precision.
Explicit versus Implicit Contracts: Evidence from CEO Employment Agreements
Authors: GILLAN STUART L. , HARTZELL JAY C. , PARRINO ROBERT
Published: July 2009

We report evidence on the determinants of whether the relationship between a firm and its Chief Executive Officer (CEO) is governed by an explicit (written) or an implicit agreement. We find that fewer than half of the CEOs of S&P 500 firms have comprehensive explicit employment agreements. Consistent with contracting theory, explicit agreements are more likely to be observed and are likely to have a longer duration in situations in which the sustainability of the relationship is less certain and where the expected loss to the CEO is greater if the firm fails to honor the agreement.
Control Rights and Capital Structure: An Empirical Investigation
Authors: ROBERTS MICHAEL R. , SUFI AMIR
Published: July 2009

We show that incentive conflicts between firms and their creditors have a large impact on corporate debt policy. Net debt issuing activity experiences a sharp and persistent decline following debt covenant violations, when creditors use their acceleration and termination rights to increase interest rates and reduce the availability of credit. The effect of creditor actions on debt policy is strongest when the borrower's alternative sources of finance are costly. In addition, despite the less favorable terms offered by existing creditors, borrowers rarely switch lenders following a violation.
Agency Problems at Dual‐Class Companies
Authors: MASULIS RONALD W. , WANG CONG , XIE FEI
Published: July 2009

Using a sample of U.S. dual‐class companies, we examine how divergence between insider voting and cash flow rights affects managerial extraction of private benefits of control. We find that as this divergence widens, corporate cash holdings are worth less to outside shareholders, CEOs receive higher compensation, managers make shareholder value‐destroying acquisitions more often, and capital expenditures contribute less to shareholder value. These findings support the agency hypothesis that managers with greater excess control rights over cash flow rights are more prone to pursue private benefits at shareholders’ expense, and help explain why firm value is decreasing in insider excess control rights.
Analyzing the Tax Benefits from Employee Stock Options
Authors: BABENKO ILONA , TSERLUKEVICH YURI
Published: July 2009

Employees tend to exercise stock options when corporate taxable income is high, shifting corporate tax deductions to years with higher tax rates. If firms paid employees the same dollar value in wages instead of stock options, the average annual tax bill for large U.S. companies would increase by $12.6 million, or 9.8%. These direct tax benefits of options increase in the convexity of the tax function. In addition, profitable firms can realize indirect tax benefits because stock options increase debt capacity. Although tax minimization is probably not the main motive for option grants, firms with larger potential tax benefits grant more options.
Rewriting History
Authors: LJUNGQVIST ALEXANDER , MALLOY CHRISTOPHER , MARSTON FELICIA
Published: July 2009

We document widespread changes to the historical I/B/E/S analyst stock recommendations database. Across seven I/B/E/S downloads, obtained between 2000 and 2007, we find that between 6,580 (1.6%) and 97,582 (21.7%) of matched observations are different from one download to the next. The changes include alterations of recommendations, additions and deletions of records, and removal of analyst names. These changes are nonrandom, clustering by analyst reputation, broker size and status, and recommendation boldness, and affect trading signal classifications and back‐tests of three stylized facts: profitability of trading signals, profitability of consensus recommendation changes, and persistence in individual analyst stock‐picking ability.
Limitations of Dower's Inverse Transform for the Study of Atrial Loops during Atrial Fibrillation
Authors: GUILLEM MARÍA S. , CLIMENT ANDREU M. , BOLLMANN ANDREAS , HUSSER DANIELA , MILLET JOSÉ , CASTELLS FRANCISCO
Published: July 2009

Introduction: Spatial characteristics of atrial fibrillatory waves have been extracted by using a vectorcardiogram (VCG) during atrial fibrillation (AF). However, the VCG is usually not recorded in clinical practice and atrial loops are derived from the 12‐lead electrocardiogram (ECG). We evaluated the suitability of the reconstruction of orthogonal leads from the 12‐lead ECG for fibrillatory waves in AF.

Methods: We used the Physikalisch‐Technische Bundesanstalt diagnostic ECG database, which contains 15 simultaneously recorded signals (12‐lead ECG and three Frank orthogonal leads) of 13 patients during AF. Frank leads were derived from the 12‐lead ECG by using Dower's inverse transform. Derived leads were then compared to true Frank leads in terms of the relative error achieved. We calculated the orientation of AF loops of both recorded orthogonal leads and derived leads and measured the difference in estimated orientation. Also, we investigated the relationship of errors in derivation with fibrillatory wave amplitude, frequency, wave residuum, and fit to a plane of the AF loops.

Results: Errors in derivation of AF loops were 68 ± 31% and errors in the estimation of orientation were 35.85 ± 20.43°. We did not find any correlation among these errors and amplitude, frequency, or other parameters.

Conclusions: In conclusion, Dower's inverse transform should not be used for the derivation of orthogonal leads from the 12‐lead ECG for the analysis of fibrillatory wave loops in AF. Spatial parameters obtained after this derivation may differ from those obtained from recorded orthogonal leads.
Atrial Fibrillation Significantly Increases Total Mortality and Stroke Risk Beyond that Conveyed by the CHADS2 Risk Factors
Authors: CRANDALL MARK A. , HORNE BENJAMIN D. , DAY JOHN D. , ANDERSON JEFFREY L. , MUHLESTEIN JOSEPH B. , CRANDALL BRIAN G. , WEISS J. PETER , OSBORNE JEFFREY S. , LAPPÉ DONALD L. , BUNCH T. JARED
Published: July 2009

Background: Atrial fibrillation (AF) is associated with an increased risk of mortality and stroke. However, it is unclear if AF is independently associated with these poor outcomes or it is merely a risk marker of other processes that convey the risk.

Methods: Consecutive patients who underwent angiography for suspicion of coronary artery disease, but without a history of AF, were studied. Traditional CHADS2 (congestive heart failure, hypertension, age >75 years, diabetes, stroke/transient ischemic attack) risk factors for each patient were recorded.

Results: A total of 343 AF patients (age = 69 ± 10 years, 215 [63%] male) and 2,945 non‐AF patients (age = 63 ± 12 years, 2,012 [67%] male) were studied. Among AF patients, 51 (15%) had a myocardial infarction (MI), 35 (10%) had a stroke, and 180 (52%) died. CHADS2 score incrementally increased risk of stroke (adjusted hazard ratio [HR] for 1:1.92, 2:2.30, 3:1.14, 4:3.83, 5:10.96; P‐trend = 0.14), death (HR for 1:1.83, 2:2.34, 3:3.69, 4:2.27, 5:4.53; P‐trend < 0.001), and major adverse cardiac event (MACE)
(HR for 1:1.29, 2:1.54, 3:2.07, 4:2.41, 5:2.68; P‐trend = 0.002). Among non‐AF patients, CHADS2 score incrementally increased risk of stroke (HR for 1:1.18, 2:3.17, 3:5.08, 4:10.78, 5:7.50; P‐trend < 0.001), MI (HR for 1:1.05, 2:1.46, 3:1.57, 4:0.53, 5:4.76; P‐trend = 0.002), death (HR for 1:1.79, 2:3.22, 3:6.23, 4:9.09, 5:14.00; P‐trend < 0.001), and MACE (HR for 1:1.47, 2:2.36, 3:4.16, 4:5.91, 5:7.56; P‐trend < 0.001). Among all patients, both CHADS2 score (all P ≤ 0.001) and AF were independent risk factors for stroke (AF: P = 0.002), MI (AF: P = 0.035), death (AF: P < 0.001), and MACE (AF: P < 0.001).

Conclusion: The CHADS2 score is a powerful predictor of stroke and death. AF increases the risk of these outcomes in an independent manner. These data support the concept that AF is a risk factor of future cardiovascular disease.
Catheter Ablation versus Standard Conventional Treatment in Patients with Left Ventricular Dysfunction and Atrial Fibrillation (CASTLE‐AF) ‐ Study Design
Authors: MARROUCHE NASSIR F. , BRACHMANN JOHANNES ,   on behalf of the CASTLE‐AF Steering Committee
Published: July 2009

Background: Electrical isolation of the pulmonary veins by catheter ablation is an emerging treatment modality for the treatment of atrial fibrillation (AF) and is increasingly used in patients with heart failure.

Methods: The catheter ablation versus standard conventional treatment in patients with left ventricular dysfunction and atrial fibrillation trial (CASTLE‐AF) is a randomized evaluation of ablative treatment of atrial fibrillation in patients with left ventricular dysfunction. The primary endpoint is the composite of all‐cause mortality or worsening of heart failure requiring unplanned hospitalization using a time to first event analysis. Secondary endpoints are all‐cause mortality, cardiovascular mortality, cerebrovascular accidents, worsening of heart failure requiring unplanned hospitalization, unplanned hospitalization due to cardiovascular reason, all‐cause hospitalization, quality of life, number of therapies (shock and antitachycardia pacing) delivered by the implantable cardioverter‐defibrillator (ICD), time to first ICD therapy, number of device‐detected ventricular tachycardia and ventricular fibrillation episodes, AF burden, AF free interval, left ventricular function, exercise tolerance, and percentage of right ventricular pacing. CASTLE‐AF will randomize 420 patients for a minimum of 3 years at 48 sites in the United States, Europe, Australia, and South America.
Atrial Fibrillation Ablation in Patients with Therapeutic International Normalized Ratios
Authors: SCHMIDT MARTIN , SEGERSON NATHAN M. , MARSCHANG HARALD , AKOUM NAZEM , RITTGER HARALD , CLIFFORD SARAH M. , BRACHMANN JOHANNES , DACCARETT MARCOS , MARROUCHE NASSIR F
Published: July 2009

Aims: Pulmonary vein antrum isolation (PVAI) plays a pivotal role in the comprehensive treatment of atrial fibrillation (AF). The need for effective anticoagulation bridging following PVAI is associated with significant vascular complication rates and increased costs.

We investigated the safety of PVAI in patients with therapeutic international normalized ratios (INR) the day of the procedure.

Methods: A case‐control analysis was performed on patients who underwent PVAI with therapeutic INR (>2). Patients with normal preprocedure INR served as controls. The incidence of major and minor hematomas, fistulas, vascular injury, and cardiac perforation or tamponade were catalogued. PVAI was performed under fluoroscopic, electro‐anatomical, and intracardiac echocardiographic guidance, with an open irrigation ablation technique.

Results: A total of 194 patients (mean age 64 ± 12) were included; 87 patients underwent PVAI with therapeutic INR (cases) and 107 with normal INR (controls). Persistent AF was more prevalent than paroxysmal AF in the therapeutic INR group. The mean INR for cases was 2.8 ± 0.7 compared to 1.4 ± 0.3 in the control group (P < 0.01). All procedures were completed without acute complications. Two major adverse events were observed, one in each arm. No significant difference in terms of minor (6.5% vs. 5.7%, P = 0.23) or major (0.93% vs. 1.15%, P = 0.49) vascular events or bleeding was detected between the therapeutic INR and the control group. The combined endpoint of major and minor complications did not differ among groups (9.35% vs. 8.05%, P = 0.19).

Conclusion: Atrial fibrillation ablation in patients with therapeutic INR on the day of a procedure appears to be safe and feasible. Expensive outpatient anti‐coagulation bridging may be safely avoided in this type of population.
Relevance of Echocardiographic Evaluation of Right Ventricular Function in Patients Undergoing Cardiac Resynchronization Therapy
Authors: SCUTERI LEA , RORDORF ROBERTO , MARSAN NINA AJMONE , LANDOLINA MAURIZIO , MAGRINI GIULIA , KLERSY CATHERINE , FRATTINI FOLCO , PETRACCI BARBARA , VICENTINI ALESSANDRO , CAMPANA CARLO , TAVAZZI LUIGI , GHIO STEFANO
Published: July 2009

Aims: Right ventricular (RV) dysfunction is a marker of poor prognosis in heart failure (HF) patients. It is still unclear whether RV function might influence response to cardiac resynchronization therapy (CRT).

Methods: Forty‐four consecutive patients with HF, large QRS, and either intraventricular or interventricular dyssynchrony underwent echocardiographic evaluation before, 1 month after, and 6 months after CRT. Response to CRT was considered in case of significant LV reverse remodeling, defined as the occurrence of LV end‐systolic volume (LVESV) reduction ≥15% at 6 months.

Results: All echocardiographic indexes of baseline RV function and dimensions were significantly more impaired in nonresponders versus responders to CRT: tricuspid annular plane systolic excursion (TAPSE 15 ± 4 mm vs 20 ± 5 mm, P = 0.001), RV systolic pulmonary artery pressure (RVSP 39 ± 14 mmHg vs 27 ± 8 mmHg, P = 0.02), RV end‐diastolic area (RVEDA 23 ± 6 cm2 vs 16 ± 3 cm2 P < 0.001), RV end‐systolic area (RVESA 16 ± 6 cm2 vs 8 ± 2 cm2, P = 0.001), and RV fractional area change (30 ± 12% vs 48 ± 8%, P < 0.001). All the indexes of RV function significantly correlated with the percentage of LVESV reduction after CRT. Severe RV dysfunction was defined as TAPSE ≤14 mm and the population was stratified into two groups based on baseline TAPSE ≤ or > 14 mm. As compared to those with high TAPSE (n = 30), patients with low TAPSE (n = 14) were less likely to show LV reverse remodeling after CRT (76% vs 14%, P < 0.001).

Conclusions: Our study suggests that RV function significantly affects response to CRT. Poor LV reverse remodeling occurs after CRT in patients with HF having severe RV dysfunction at baseline.