bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression and distribution of cell‐surface proteoglycans in the normal Lewis rat molar periodontium
Authors: Worapamorn W. , Li H. , Pujic Z. , Xiao Y. , Young W. G. , Bartold P. M.
Published: December 2003

Cell‐surface proteoglycans participate in several biological functions such as cell–cell and cell–matrix interactions, cell adhesion, the binding to various growth factors as co‐receptors and repair. To understand better the expression and distribution of cell‐surface proteoglycans in the periodontal tissues, an immunohistochemical evaluation of the normal Lewis rat molar periodontium using panels of antibodies for syndecan‐1, ‐2, ‐4, glypican and betaglycan was carried out. Our results demonstrated the expression and distribution of all proteoglycans in the suprabasal gingival epithelium, soft and hard connective tissues. Both cellular and matrix localization was evident within the various periodontal compartments. The presence of these cell‐surface proteoglycans indicates the potential for roles in the process of tissue homeostasis, repair or regeneration in periodontium of which each function requires further study.
In vitro evaluation of Er:YAG laser scaling of subgingival calculus in comparison with ultrasonic scaling
Authors: Aoki A. , Miura M. , Akiyama F. , Nakagawa N. , Tanaka J. , Oda S. , Watanabe H. , Ishikawa I.
Published: December 2003

The purpose of the present study was to evaluate the effectiveness of Er:YAG laser scaling and the morphological and histological changes of the laser‐scaled root surface in comparison with the effectiveness and root surface changes produced by conventional ultrasonic scaling. Fifty‐three periodontally involved human extracted teeth with a band of subgingival calculus were used. The teeth were divided randomly into 2 groups for laser scaling and ultrasonic scaling. Laser irradiation was performed at an energy output of 40 mJ/pulse and 10 pulses/s under water spray, with the probe tip contacted obliquely to the root surface. Ultrasonic scaling was performed at a clinically standard power setting. The time required for scaling, the scaled area and the temperature changes were determined using both methods of treatment. The features of the scaled surfaces were examined by histological and scanning electron microscope (s.e.m.) observations. The Er:YAG laser provided subgingival calculus removal on a level equivalent to that provided by the ultrasonic scaler, without major thermal elevation. Macroscopically, the laser‐treated root surface was somewhat rougher than or similar to the ultrasonically scaled root. However, the efficiency of the laser scaling was lower than that of the ultrasonic scaling. In addition, histological examination revealed a thin deeply stained zone on the lased root surface, and s.e.m. analysis revealed a characteristic microroughness on the lased surface. The laser scaling provided a level of calculus removal that was similar to that provided by the ultrasonic scaling. However, the Er:YAG laser produced superficial, structural and thermal microchanges on the root cementum.
Light and electron microscopic study of the initial attachment of principal fibers to the alveolar bone surface in rat molars
Authors: Islam M. N. , Yamamoto T. , Wakita M.
Published: December 2003

This study was designed to observe the principal fibers and alveolar bone in various developmental stages in rat molars using light and transmission electron microscopy and to elucidate the mechanism of initial principal fiber attachment to the alveolar bone surface. Maxillary alveolar bone between the 2nd and 3rd molars of 20‐ and 25‐day‐old rats was used. A proteoglycan‐rich, fiber‐poor, and electron dense layer formed on the alveolar bone surface before the principal fiber organization. This layer was not seen before principal fibers had started to develop. Principal fibers first contacted and then became embedded in this layer. With further development, new bone deposited on this layer and around already attached principal fibers. These findings suggest that this electron dense, proteoglycan‐rich layer may act as an adhesive factor to mediate the initial attachment of principal fibers to the alveolar bone surface.
Cytological and cytogenetic effects of the fluoroquinolone ofloxacin on human periodontal ligament fibroblasts
Authors: Someya Tetsuro , Tamura Yukiko , Tsutsui Takeki
Published: December 2003

The fluoroquinolone ofloxacin (OFLX) is one of the candidates of antibacterial agents to be topically used against periodontitis. To estimate the maximum concentration of OFLX which exerts little or no adverse effect on the periodontal ligament, cytological and cytogenetic effects of OFLX on human periodontal ligament fibroblasts (Pel cells) were examined. Treatment of Pel cells with ≤0.3 mm OFLX for 24 or 48 h had little inhibitory effect on cellular growth and survival. DNA, RNA and protein syntheses in Pel cells did not decrease in response to treatment with ≤0.3 mm OFLX. The constitutive level of alkaline phosphatase mRNA was retained in cells treated with ≤0.03 mm OFLX for 24 or 48 h. The level of type I procollagen mRNA was not affected by treatment with ≤0.003 mm OFLX for 24 or 48 h. Cytogenetic effects of OFLX were evaluated by the ability of OFLX to induce chromosome aberrations in Pel cells. Treatment with OFLX at 0.3–3.0 mm for 6, 24, or 48 h failed to induce chromosome aberrations in Pel cells. The failure of OFLX to induce chromosome aberrations was seen even in the presence of exogenous metabolic activation using a 5% rat liver post‐mitochondrial supernatant mixture. These results indicate that treatment of Pel cells with ≤0.003 mm OFLX has few or no adverse effects on the cytological and cytogenetic endpoints examined, suggesting that there would be little adverse effect on growth and differentiation of the periodontal ligament, as well as little cytogenetic activity, if OFLX were to be topically administered to the gingival crevice at the minimal inhibitory concentration (MIC90) against periodontopathic bacteria (≤0.0027 mm). It is important to note, however, that extrapolation of these findings to in vivo conditions has yet to be undertaken.
New Economy, Old Central Banks?
Authors: Berk Jan Marc
Published: December 2003

Proponents of the so‐called New Economy claim that it entails a structural change of the economy. Such a change, in turn, would require the central bank to rethink its monetary policy to the extent that traditional relationships between inflation and economic growth are no longer valid. Such a rethinking, though, presupposes that prospective advances in information technology and other factors associated with the new economy do not threaten the capacity of central banks to stabilize the general level of prices. It is the aim of this paper to shed some light on the latter, by analysing the monetary transmission mechanism in a ‘new economy’ environment. We argue that, although the form of central bank instruments and current methods for implementing monetary policy may change, the goals that the policy makers try to achieve by employing these instruments remain valid, and achievable.
Roger B. Porter, Pierre Sauvé, Arvind Subramanian and Amerito B. Zampetti (eds) (2001) Efficiency, Equity, Legitimacy: The Multilateral Trading System at the Millennium
Authors: Rossini Gianpaolo
Published: December 2003

Book reviewed in this article:

Roger B. Porter, Pierre Sauvé, Arvind Subramanian and Amerito B. Zampetti (eds), Efficiency, Equity, Legitimacy: The Multilateral Trading System at the Millennium
Joseph E. Stiglitz (2002) Globalization and Its Discontents
Authors: Ferri Giovanni
Published: December 2003

Book reviewed in this article:

Joseph E. Stiglitz, Globalization and Its Discontents
Transforming Growth Factor-β Production and Myeloid Cells Are an Effector Mechanism through Which CD1d-restricted T Cells Block Cytotoxic T Lymphocyte–mediated Tumor Immunosurveillance
Authors: Terabe Masaki , Matsui So , Park Jong-Myun , Mamura Mizuko , Noben-Trauth Nancy , Donaldson Debra D. , Chen Wanjun , Wahl Sharon M. , Ledbetter Steven , Pratt Bruce , Letterio John J. , Paul William E. , Berzofsky Jay A.
Published: December 2003

Our previous work demonstrated that cytotoxic T lymphocyte (CTL)-mediated tumor immunosurveillance of the 15-12RM tumor could be suppressed by a CD1d-restricted lymphocyte, most likely a natural killer (NK) T cell, which produces interleukin (IL)-13. Here we present evidence for the effector elements in this suppressive pathway. T cell–reconstituted recombination activating gene (RAG)2 knockout (KO) and RAG2/IL-4 receptor α double KO mice showed that inhibition of immunosurveillance requires IL-13 responsiveness by a non–T non–B cell. Such nonlymphoid splenocytes from tumor-bearing mice produced more transforming growth factor (TGF)-β, a potent inhibitor of CTL, ex vivo than such cells from naive mice, and this TGF-β production was dependent on the presence in vivo of both IL-13 and CD1d-restricted T cells. Ex vivo TGF-β production was also abrogated by depleting either CD11b+ or Gr-1+ cells from the nonlymphoid cells of tumor-bearing mice. Further, blocking TGF-β or depleting Gr-1+ cells in vivo prevented the tumor recurrence, implying that TGF-β made by a CD11b+ Gr-1+ myeloid cell, in an IL-13 and CD1d-restricted T cell–dependent mechanism, is necessary for down-regulation of tumor immunosurveillance. Identification of this stepwise regulation of immunosurveillance, involving CD1-restricted T cells, IL-13, myeloid cells, and TGF-β, explains previous observations on myeloid suppressor cells or TGF-β and provides insights for targeted approaches for cancer immunotherapy, including synergistic blockade of TGF-β and IL-13.
An Immunologically Privileged Retinal Antigen Elicits Tolerance
Authors: Avichezer Dody , Grajewski Rafael S. , Chan Chi-Chao , Mattapallil Mary J. , Silver Phyllis B. , Raber James A. , Liou Gregory I. , Wiggert Barbara , Lewis Giavonni M. , Donoso Larry A. , Caspi Rachel R.
Published: December 2003

Immunologically privileged retinal antigens can serve as targets of experimental autoimmune uveitis (EAU), a model for human uveitis. The tolerance status of susceptible strains, whose target antigen is not expressed in the thymus at detectable levels, is unclear. Here, we address this issue directly by analyzing the consequences of genetic deficiency versus sufficiency of a uveitogenic retinal antigen, interphotoreceptor retinoid-binding protein (IRBP). IRBP-knockout (KO) and wild-type (WT) mice on a highly EAU-susceptible background were challenged with IRBP. The KO mice had greatly elevated responses to IRBP, an altered recognition of IRBP epitopes, and their primed T cells induced exacerbated disease in WT recipients. Ultrasensitive immunohistochemical staining visualized sparse IRBP-positive cells, undetectable by conventional assays, in thymi of WT (but not of KO) mice. IRBP message was PCR amplified from these cells after microdissection. Thymus transplantation between KO and WT hosts demonstrated that this level of expression is functionally relevant and sets the threshold of immune (and autoimmune) reactivity. Namely, KO recipients of WT thymi generated reduced IRBP-specific responses, and WT recipients of KO thymi developed enhanced responses and a highly exacerbated disease. Repertoire culling and thymus-dependent CD25+ T cells were implicated in this effect. Thus, uveitis-susceptible individuals display a detectable and functionally significant tolerance to their target antigen, in which central mechanisms play a prominent role.
Carbon Monoxide Protects against Liver Failure through Nitric Oxide–induced Heme Oxygenase 1
Authors: Zuckerbraun Brian S. , Billiar Timothy R. , Otterbein Sherrie L. , Kim Peter K.M. , Liu Fang , Choi Augustine M.K. , Bach Fritz H. , Otterbein Leo E.
Published: December 2003

Carbon monoxide (CO) and nitric oxide (NO) each have mechanistically unique roles in various inflammatory disorders. Although it is known that CO can induce production of NO and that NO can induce expression of the cytoprotective enzyme heme oxygenase 1 (HO-1), there is no information whether the protective effect of CO ever requires NO production or whether either gas must induce expression of HO-1 to exert its functional effects. Using in vitro and in vivo models of tumor necrosis factor α–induced hepatocyte cell death in mice, we find that activation of nuclear factor κB and increased expression of inducible NO are required for the protective effects of CO, whereas the protective effects of NO require up-regulation of HO-1 expression. When protection from cell death is initiated by CO, NO production and HO-1 activity are each required for the protective effect showing for the first time an essential synergy between these two molecules in tandem providing potent cytoprotection.
Arbitrator Compromise in Final Offer Arbitration: Evidence from Major League Baseball
Authors: Marburger Daniel R.
Published: December 2003

This article presents evidence that the preferred awards of arbitrators in final‐offer arbitration (FOA) compromise between the perspectives of the bargainers. Using Major League Baseball FOA offers between 1986–2002, this study finds strong evidence that final offers (which are strategically formulated around the preferred award) are a weighted average of the player's salary in the previous season and the average free agent salary. The findings are particularly interesting because FOA was created to eliminate arbitrator compromise.
The “Law of One Price” in 1901
Authors: Eckard E. Woodrow
Published: December 2003

Price dispersion in 1901 is analyzed using a unique U.S. government survey yielding retail prices for four products at more than 1500 stores nationwide. Three of these products are still sold today, allowing comparisons based on modern survey data. Despite the introduction of significant search cost‐reducing technology during the intervening century, dispersion appears to be lower in 1901.
Finance and the Sources of Growth at Various Stages of Economic Development
Authors: Rioja Felix , Valev Neven
Published: December 2003

This article studies the effects of financial development on the sources of growth in different groups of countries. Recent theoretical work shows that financial development may affect productivity and capital accumulation in different ways in industrial versus developing countries. This hypothesis is tested with panel data from 74 countries using GMM dynamic panel techniques. Results are consistent with the hypothesis: finance has a strong positive influence on productivity growth primarily in more developed economies. In less developed economies, the effect of finance on output growth occurs primarily through capital accumulation.
Organisational self‐assessment options
Authors: Biazzo Stefano , Bernardi Giovanni
Published: November 2003

The growing importance and considerable prestige that quality awards hold have encouraged firms to adopt “excellence models” as evaluation frameworks for organisational self‐assessment. This has contributed to the spread of a specific form of self‐assessment logic: primarily, the search for conformity to a set of non‐prescriptive requirements that reflect validated, leading‐edge management practices; secondarily, the search of alignment of practices with organisational needs and business factors. But the adoption of this kind of self‐assessment is not necessarily the proper “choice”, particularly for small and medium‐sized enterprises (SMEs). This paper examines the nature of the diagnostic processes incorporated in award‐based self‐assessment and in other diagnostic models developed in the organisational literature. This analysis provides the foundation for the development of a classification matrix that enables us to differentiate five self‐assessment approaches (paradigmatic, normative, situational, normative‐situational, and open), which can be implemented either with a process‐based or a non‐process‐based analytical frame. On the basis of this matrix we outline a “conceptual map” that could help SMEs in questioning the meaning and substance of “organisational self‐assessment” so as to choose knowingly and rationally frameworks and diagnostics instruments.
Customer‐centric six sigma quality and reliability management
Authors: Kuei Chu‐Hua , Madu Christian N.
Published: November 2003

This paper presents a customer‐centric six sigma quality management as an extension of the traditional six sigma way. It views product quality and process reliability as key to achieving six sigma and adopts a holistic view of quality. The aim is to offer practical guidelines to business leaders, practicing mangers and those interested in quality, the new directions in quality management. It views reliability management as an integral part of any six sigma strategy since the focus in reliability management is on process reliability and dependability. Thus, by bringing both product and process quality together, a customer‐centric six sigma can be achieved.
A Note on Adjusting National Input‐Output Data for Regional Table Construction
Authors: Comer Jonathan C. , Jackson Randall W.
Published: December 2003

Regional analysts face a trade‐off between timeliness and detail of commodity‐industry data. The trade‐off exists because the Bureau of Economic Analysis national aggregated annual update tables are published for years more recent than those for which the disaggregated benchmark accounts are available. Conventional wisdom holds that regionalization should precede aggregation, so a disaggregated foundation table is preferred to an aggregation of that same table. This paper shows that the Table Disaggregation and Adjustment (TDA) method of Jackson and Comer (1993) produces a better foundation for regionalization than an unadjusted benchmark, price‐updated benchmark, or aggregated annual update table.
Deficits, Money Growth and Inflation in Italy: 1875–1994
Authors: Favero Carlo A. , Spinelli Franco
Published: December 2003

In this paper, we examine econometrically the “fiscal dominance” model of the Monetary History of Italy proposed by Spinelli and Fratianni (1996). We test the proposition that monetary policy is endogenous to fiscal policy, and that such an endogeneity creates a specificity in the process generating Italian inflation. We perform our econometric tests by estimating a small structural linear econometric model, addressing carefully the issues of data‐congruency of the specification, non‐stationarity, cointegration, and credibility of the over‐identifying restrictions. Our econometric investigation is based on a sample of annual observations from 1875–1994 and exploits the structural break which occurred in 1975, when Baffi became Governor of the Bank of Italy and the lack of independence of the central bank was first perceived as a problem. Baffi started the slow evolution process leading to the independence of the central bank, which was institutionally ratified by his successor Ciampi, when, in 1981, the Bank of Italy interrupted his commitment to buy all the government bonds left unsold in the public tenders (the “divorce”). Our empirical analysis over the sample 1875–1975 confirms the existence of a link between government deficit and money growth, and of a long‐run relationship between the quantity of money and the price level; the evidence also stresses the relevance of supply side factors in the determination of inflation. When the model estimated for the sample 1875–1975 is applied to the period 1975–1994, a clear structural break in the relation between government deficits and money growth emerges. (J.E.L.: E5, E6).
The Term Structure of Interest Differentials in a Target Zone with Time‐varying Devaluation Risk
Authors: Knot Klaas , Dijkstra Theo , Haan Jakob de
Published: December 2003

We extend Svensson's (1991b) analysis of the term structure of interest rate differentials in a target zone. First, the model includes a time‐varying devaluation risk, and second, we analyse the term structure of interest differentials vis‐a‐vis Germany in five countries: Belgium, Denmark, France, Italy and the Netherlands. In our sample, 1983–1993, we differentiate between stable and unstable periods. The findings for Denmark and the Netherlands, and for Belgium in the relatively stable period are broadly in line with Svensson's theory, whereas the other results are more in accordance with the model that allows for a time‐varying devaluation risk.

(J.E.L. E43, F31).
The Procyclical Role of Rating Agencies: Evidence from the East Asian Crisis
Authors: Ferri G. , Liu L.‐G. , Stiglitz J. E.
Published: December 2003

We demonstrate that credit rating agencies aggravated the East Asian crisis. In fact, having failed to predict the emergence of the crisis, rating agencies became excessively conservative. They downgraded East Asian crisis countries more than the worsening in these countries' economic fundamentals would justify. This unduly exacerbated, for these countries, the cost of borrowing abroad and caused the supply of international capital to them to evaporate. In turn, lower than deserved ratings contributed – at least for some time – to amplify the East Asian crisis. Although this goes beyond the scope of our paper, we also propose an endogenous rationale for rating agencies to become excessively conservative after having made blatant errors in predicting the East Asian crisis. Specifically, rating agencies would have an incentive to become more conservative, so as to recover from the damage these errors caused to them and to rebuild their own reputation.
Private and Government Employment in the OECD: Productivities and Wages
Authors: Karras Georgios
Published: December 2003

This paper estimates the productivity of private and government employment for a panel of 23 OECD economies over the 1961–1992 period, and investigates their relation to the government/private wage ratio. The paper finds that (i) the elasticities of output with respect to private and government employment are statistically significantly different from each other; (ii) the marginal products of private and government employment are not statistically significantly different, which suggests that government employment is neither over‐ nor under‐provided, and that shifting employment from one sector to the other is not likely to produce substantial output gains; and (iii) in most of the countries examined, government workers are overpaid in the sense that the government/private wage ratio exceeds the corresponding ratio of marginal products.

(J.E.L. E24, E62).
Liquidity Creation through Banks and Markets: A Theoretical Perspective on Securitization
Authors: Von Thadden Ernst‐Ludwig
Published: December 2003

Securitization is a process that transforms some traditional non‐traded banking assets into marketable securities. To evaluate this process, this paper surveys theories of the intertemporal allocation of funds through demand deposits and anonymous markets, first separately and then in an integrated model. It reviews some work on the role of market frictions and asset characteristics, and concludes that the interplay between these two is crucial in explaining the observed co‐existence of demand deposits and anonymous markets. This suggests that securitization is an opportunity, rather than a threat, to banks.

(J.E.L.: D50, G21)
Does Correlation Between Stock Returns Really Increase During Turbulent Periods?
Authors: Chesnay Francois , Jondeau Eric
Published: December 2003

Correlations betwen international equity markets are often claimed to increase during periods of high volatility. Therefore the benefits of international diversification are reduced when they are most needed, i.e. during turbulent periods. This paper investigates the relationship between international correlation and stock‐market turbulence. We estimate a multivariate Markov‐switching model, in which the correlation matrix varies across regimes. Subsequently, we test the null hypothesis that correlations are regime‐independent. Using weekly stock returns for the S&P, the DAX and the FTSE over the period 1988–99, we find that international correlations significantly increased during turbulent periods.

(J.E.L.: C53, G15).
Measuring Monetary Policy Shocks in a Small Open Economy
Authors: Arcangelis Giuseppe De , Giorgio Giorgio Di
Published: December 2003

This paper presents different specifications of a structural VAR model which are useful to identify monetary policy shocks and their macroeconomic effects for the Italian economy in the 1990s. The analysis is based on a detailed institutional description of the functioning of the domestic market for bank reserves. In this setting, we try to establish if monetary policy shocks are better identified using exchange rates or foreign exchange reserves as a conditioning variable for the small open economy framework. Our analysis confirms the view that the Bank of Italy has been targeting the rate on overnight interbank loans in the 1990s. This is coherent with either proposed modelling choices. Therefore, we interpret shocks to the overnight rate as purely exogenous monetary policy shocks and study how they impact the economy.

(J.E.L.: E52, F41, F47).
On the Institutional Design of the European Monetary Union: Conservatism, Stability Pact and Economic Shocks
Authors: Gambacorta Leonardo
Published: December 2003

The aim of this paper is to design the optimal institutional arrangement for a monetary union. Using a two‐country rational expectations model, the study analyses how the conservatism of the area‐wide central bank and the penalty system for fiscal deviation (Stability and Growth Pact) should be designed with respect to different economic shocks. The optimal institutional arrangement is also dependent on who is the ‘leader’ of the policy game. When national governments move first, the independent area‐wide central bank can exercise greater discipline over national fiscal policies, making the Stability Pact unnecessary.

(J.E.L.: E58, E63, F42).
Competition Among Banks, Capital Requirements and International Spillovers
Authors: Acharya Viral V.
Published: December 2003

The design of prudential bank capital requirements interacts with the industrial organization of the banking sector, in particular, with the level of competition among banks. Increased competition leads to excessive risk‐taking by banks which may have to be counteracted by tighter capital requirements. When capital requirements are internationally uniform but the levels of competition among banks in different countries are not, international spillovers arise on financial integration of these countries. This result begs a more careful analysis of the effect of financial liberalization on the stability of banking sectors in emerging countries. It also calls into question the merits of employing uniform capital requirements across countries that diverge in the industrial organization of their banking sectors.

(J.E.L.: G21, G28, G38, F36, E58, D62)
Perverse Effects of an External Ratings‐Related Capital Adequacy System
Authors: Honohan Patrick
Published: December 2003

It has recently been proposed that banks should be allowed to hold less capital against loans to borrowers who have received a favourable rating by an approved external credit assessment institution (ECAI), or rating agency. But a plausible model of rating agency behaviour shows that this strategy could have perverse results, actually increasing the risk of deposit insurance outlays. First, there is an issue of signalling, whereby low‐ability borrowers may alter their behaviour so as to secure a lower capital requirement for their borrowing. Second, the establishment of a regulatory cut‐off may actually reduce the amount of risk information made available by raters. Besides, the credibility of rating agencies may not be damaged by neglect of the risk of unusual systemic shocks, though it is these that cause the major bank failure costs.

(J.E.L.:E53, G21, G33)
Enforcing the 1988 Basel Capital Requirements: Did it Curtail Bank Credit in Emerging Economies?
Authors: Chiuri Maria Concetta , Ferri Giovanni , Majnoni Giovanni
Published: December 2003

We examine whether the enforcement of bank capital asset requirements (CARs) curtailed the supply of credit in emerging economies. Preliminarily, we identify 16 emerging economies that – according to official and impartial reports – enforced the 1988 Basel standard during the 1990s. Then we perform our twofold econometric analysis. In the former part, we use macro data to test whether, controlling for economic fundamental variables, the enforcement brought about a slowdown in aggregate credit in these countries vis‐a‐vis other emerging economies. We find some support for our hypothesis. In the latter part, we employ individual bank data to better identify the ‘capital crunch’ effect of the enforcement. Here, we find that CAR enforcement – according to the 1988 Basel standard – significantly curtailed credit supply, particularly at less well‐capitalized banks. The two empirical parts together suggest that the CAR enforcement did curtail aggregate credit in the examined emerging countries and that this result is rooted in the attempt by under‐capitalized banks to reduce their loans. We argue that among developing countries – where banks are often the only source of financial intermediation – the positive effect of higher capital requirements, represented by the reduction of poor quality lending, may be offset by their negative impact on bank liquidity and on the level of economic activity. Hence, our results suggest that particular care is required to avoid potential negative macroeconomic effects when phasing in new and higher capital requirements in emerging economies.

(J.E.L.: G18, G21, G28)
Price Discovery and Risk Transfer in the Crude Oil Futures Market: Some Structural Time Series Evidence
Authors: Moosa Imad A.
Published: December 2003

This paper re‐examines the Garbade and Silber (1983) model with the objective of finding out if the crude oil futures market performs the functions of price discovery and risk transfer. The model is estimated, using daily data, as a system of two seemingly unrelated time series equations allowing the coefficients to be time‐varying. The empirical results reveal that the futures market performs about 60 per cent of the price discovery function, and that the elasticity of supply of arbitrage services is adequately high for the market to perform the risk transfer function.

(J.E.L: G13, C22).
Social Cost and Groves Mechanisms
Authors: Campbell Donald E.
Published: December 2003

When an individual’s reported preference scheme makes a difference to the selection of a policy, that individual’s report imposes a cost on the rest of society because the selected policy would have been different had the individual’s reported preference been different. In a paper in Economic Notes, Giacomo Bonanno argues that the penalty assessed by the pivotal mechanism is not equal to the cost that the individual’s participation imposes on the rest of society. This note argues to the contrary, by presenting what we believe to be the correct definition of social cost.

(J.E.L: D62, D71, H41).
An Extended Analytical Approach to Credit Risk Management
Authors: Kurth Alexandre , Taylor Hadley , Wagner Armin
Published: December 2003

Among the ‘reduced form models’ for measuring the credit risk of a bank's portfolio is CreditRisk+, which provides a closed–form solution for calculating the portfolio loss distribution based on an actuarial approach. The limitations of this model are well known, but they are often misinterpreted as being deeply embedded within the model. Dismantling the mathematical components of the model allows one to modify and extend it in several ways while remaining within an analytical approach. One of the most unattractive features is the orthogonality of the background factors or sectors as it hinders any resemblance to real–world macroeconomic indexes or industrial sectors and geographical areas. Among other extensions, which we mention briefly, we present in more detail how the original model can be amended to consider correlations among default risk sectors and among severity risk segments. These extensions are applied to real–life data, based on mortality rate data produced by the Italian Central Bank.

(J.E.L.: C00, C51).
Interbank Lending, Liquidity and Banking Crises
Authors: Brighi Paola
Published: December 2003

In this paper, we show that abandoning the Diamond and Dybvig hypothesis of a unique bank representing the entire banking system gives rise to the possibility of endogenizing the interbank exchanges. In a system characterized by uncertainty regarding the moment of withdrawal of deposits, access to interbank liquidity decreases the bank risk of failure and bank runs. The possibility, moreover, to invest excess liquidity in the interbank market at a positive interest rate increases expected bank profits.

(J.E.L.: E52, G21).
The Race Towards Transparency: An Experimental Investigation
Authors: Rossi Marco
Published: December 2003

To understand the current tendency toward transparency, we studied the effects of accounting disclosure in a laboratory. In our experiment, transparency in the financial accounts of the listed companies improved information efficiency; but, even after checking for fundamentals, the transparency increased the volatility of market prices. Moreover, transparency improved investors’ utility, so that their preference for more certain assets emerged. Therefore, we argue that the current race toward transparency may be better explained by firms’ and markets’ intention to attract household investments rather than to improve market efficiency.

(J.E.L.: G92, D44, D81, G12, G28).
Increasing Dependency Ratios, Pensions and Tax Smoothing
Authors: Sadka Efraim , Tanzi Vito
Published: December 2003

The implication of increasing dependency ratios for pay–as–you–go, defined–benefit pension programmes are examined. Modifications aimed at smoothing contributions while maintaining benefits intact are analysed for both open and closed economies.

(J.E.L.: H2, F3, J1).
Pricing Loans Using Default Probabilities
Authors: Turnbull Stuart M.
Published: December 2003

This paper examines the pricing of loans using the term structure of the probability of default over the life of the loan. We describe two methodologies for pricing loans. The first methodology uses the term structure of credit spreads to price a loan, after adjusting for the difference in recovery rates between bonds and loans. In loan origination, it is common practice to estimate the probability of default for a loan over a specified time horizon and the loss given default. The second methodology shows how to incorporate this information into the arbitrage free pricing of a loan. We also show how to derive an estimate of the credit spread due to liquidity risk. For both methodologies, we show how to calculate a break–even credit spread, taking into account the fee structure of a loan and the costs associated with the term structure of marginal economic capital. The break–even spread is the minimum spread for the loan to be EVA neutral in a multi–period setting.

(J.E.L.: G12, G33).
Macroeconomic News and the Euro/Dollar Exchange Rate
Authors: Galati Gabriele , Ho Corrinne
Published: December 2003

This paper investigates to what extent daily movements in the euro/dollar rate were driven by news about the macroeconomic situation in the USA and the euro area during the first two years of EMU. We examine whether market participants reacted to news in different ways depending on whether the news came from the USA or from the euro area, and whether the news was good or bad. Furthermore, we investigate whether traders’ reaction to news has changed over time. We find that macroeconomic news has a statistically significant correlation with daily movements of the euro against the dollar. However, this relationship exhibits considerable time variation. There are indications of asymmetric response, but to different extents at different times. Our results also provide evidence that the market seemed to ignore good news and remain fixated on bad news from the euro area, as often claimed in market commentaries, but only for some time. Finally, we find evidence that the impact of macroeconomic news on the euro/dollar rate was stronger when news switches from good to bad or vice versa.

(J.E.L.: F31).
Archipelagos and networks: urbanization and water privatization in the South
Authors: Bakker Karen
Published: December 2003

This paper examines the interrelationship between urbanization and water supply privatization in cities in the global South. The purpose of the paper is not to evaluate the impacts of privatization; rather, the paper analyses the differences in pathways and modes of water supply privatization, focusing on urban and contrasting with rural areas. A distinction is drawn between privatization (organizational change) and commercialization (institutional change) of water supply. Emphasis is placed upon the interrelationship between regulatory change (a shift from public to private management of water supply systems), human use of and access to water, and urban waterscapes. In contrast to metaphors of ‘networks’ so often applied in analyses of water management, the ‘archipelago’ is posited as a metaphor which better captures the complex overlapping strategies of water supply provision in urban areas in the South. Building on this metaphor, and in response to the ‘public–private’ dualism often invoked in studies of privatization, the paper outlines an alternative typology of water management in urban areas in the South. This typology foregrounds the concepts of the territorialization of corporate power as a means of understanding the articulation between privatization and urbanization processes in the South.
State forestry and spatial scale in the development discourses of post‐colonial Tanzania: 1961–1971
Authors: Hurst Andrew
Published: December 2003

At independence, Tanzanian foresters believed that state‐led forestry could provide a lasting contribution to the development aspirations of the newly independent country. Yet they were gradually marginalized within Julius Nyerere's project of socio‐economic transformation. By exploring the spatial dimensions of competing land use discourses of the time, I hope to offer an interpretation as to how and why forestry's marginalization happened. I argue that at least some of this marginalization was the result of differences inherent in the scale of focus between forestry and the larger, contemporaneous socio‐economic and political discourses dominant in the period. At independence, Nyerere positioned development efforts more squarely within the national political institutions of the state and for the nation, writ whole. With its professional and discursive ties to an international forestry order and its spatial biases, Tanzanian foresters were poorly placed to respond or adapt to changes in the political discourse and in the economic conditions of resource extraction. In short, they were unable to adjust to changes in the scale of development praxis in Tanzania. I conclude by suggesting two points. First, that the history of land use and natural resource management choices in post‐colonial Tanzania can be better understood through a historical‐geographical, or spatialized, theoretical framework. Second, that current historical‐geographical theory could be fine tuned through reflection on its utility in describing and explaining land use politics in post‐colonial developing contexts.
Markets, ethnicity and environment in a vulnerable landscape: the case of small‐scale vegetable production on the Jos Plateau, Nigeria, 1991–2001
Authors: Porter Gina , Harris Frances , Lyon Fergus , Dung Jasper , Adepetu A A
Published: December 2003

This paper explores changing socio‐environmental interactions in the vegetable producing areas of the Jos Plateau over the decade 1991–2001. It considers the pressures of market forces and ethnic competition and the tensions which arise as interactions between the two are played out in a fragile physical, social and institutional environment. The region has seen a remarkable expansion in irrigated vegetable production, as dry season surveys in 1991 and 2001 attest. Local farmers appear extremely positive in their perceptions of change, pointing not only to expanded production, but also to other improvements, like growing percentages of children in school and improved transport. But behind this rosy view of change there are tensions and a series of unresolved questions which may soon have to be addressed. We examine the changing nature of socio‐environmental interactions over the decade and ask whether and how current levels of production can be sustained in the context of a currently largely unregulated production system and growing competition for land. Given the important role of the Plateau as a source of temperate fruit and vegetables in West Africa, these questions have significance far beyond the Plateau region itself.
The cerebral oscillatory network of voluntary tremor
Authors: Pollok Bettina , Gross Joachim , Dirks Martin , Timmermann Lars , Schnitzler Alfons
Published: December 2003

It has recently been shown that resting tremor in Parkinson's disease is associated with oscillatory neural coupling in an extensive cerebral network comprising a cerebello–diencephalic–cortical loop and cortical motor, somatosensory and posterior parietal areas contralateral to the tremor hand. The aim of the present study was to investigate whether this oscillatory brain network exclusively reflects a pathophysiological state in parkinsonian resting tremor or whether it constitutes a fundamental feature of physiological motor control. We investigated cerebro‐muscular and cerebro‐cerebral coupling in 11 healthy subjects imitating typical antagonistic parkinsonian tremor. We recorded brain activity with a 122‐channel whole‐head neuromagnetometer and surface EMGs of the forearm extensor. Analysis of cerebro‐muscular and cerebro‐cerebral coherence revealed oscillatory coupling in the same brain structures that comprise the oscillatory network of parkinsonian resting tremor. Interestingly, similar to parkinsonian resting tremor, cerebro‐cerebral coherences often showed a significant peak at twice the simulated tremor frequency. The most striking differences between parkinsonian patients, as investigated in a previous study and healthy subjects imitating the antagonistic resting tremor were a reduction of the coupling between primary sensorimotor cortex and a diencephalic structure – most likely the thalamus – and an enhancement of the coupling between premotor and primary sensorimotor cortex. Our results indicate that the coupling of oscillatory activity within a cerebello–diencephalic–cortical loop constitutes a basic feature of physiological motor control. Thus, our data are consistent with the hypothesis that parkinsonian resting tremor involves oscillatory cerebro‐cerebral coupling in a physiologically pre‐existing network.
Effects of interactions between interleukin‐1β and leptin on cat intestinal vagal mechanoreceptors
Authors: Gaigé Stéphanie , Abou Einate , Abysique Anne , Bouvier Michel
Published: December 2003

In a previous study, we established that leptin acts on chemosensitive intestinal vagal mechanoreceptors and that its excitatory effects are blocked by the endogenous interleukin‐1β receptor antagonist (Il‐1ra). To determine how interleukin‐1β (Il‐1β) is involved in the action of leptin, we studied the effects of this drug on the single vagal afferent activities of intestinal mechanoreceptors in anaesthetized cats. For this purpose, the activity of 34 intestinal vagal mechanoreceptors was recorded via glass microelectrodes implanted in the nodose ganglion. Il‐1β (1 μg) administered into the artery irrigating the upper part of the intestine activated both the 16 leptin‐activated units (type 1 units; P < 0.01) and the 12 leptin‐inhibited units (type 2 units; P < 0.001), but had no effect on the six leptin‐insensitive units. Cholecystokinin (CCK, 10 μg) induced an activatory response only in the two types of Il‐1β‐sensitive units. When Il‐1β was administered after CCK, its excitatory effects on type 1 units were enhanced, whereas the excitatory effects on type 2 units were abolished. Pre‐treatment with Il‐1ra (250 μg) blocked all the effects of Il‐1β and the excitatory effects of leptin on type 1 units, whereas it enhanced the inhibitory effects of leptin on type 2 units. It can therefore be concluded that (i) leptin acts on intestinal vagal mechanoreceptors via Il‐1β in the case of the type 1 units and independently of Il‐1β in the case of the type 2 units, and (ii) type 1 and type 2 units belong to two different populations of vagal afferents that transmit different information about ingestion or inflammation to the CNS, depending on the chemical environment.
ATP-Driven Exchange of Histone H2AZ Variant Catalyzed by SWR1 Chromatin Remodeling Complex
Authors: Mizuguchi Gaku , Shen Xuetong , Landry Joe , Wu Wei-Hua , Sen Subhojit , Wu Carl
Published: December 2003

The conserved histone variant H2AZ has an important role in the regulation of gene expression and the establishment of a buffer to the spread of silent heterochromatin. How histone variants such as H2AZ are incorporated into nucleosomes has been obscure. We have found that Swr1, a Swi2/Snf2-related adenosine triphosphatase, is the catalytic core of a multisubunit, histone-variant exchanger that efficiently replaces conventional histone H2A with histone H2AZ in nucleosome arrays. Swr1 is required for the deposition of histone H2AZ at specific chromosome locations in vivo, and Swr1 and H2AZ commonly regulate a subset of yeast genes. These findings define a previously unknown role for the adenosine triphosphate–dependent chromatin remodeling machinery.
Formaldehyde-Detoxifying Role of theTetrahydromethanopterin-Linked Pathway in
Methylobacteriumextorquens
AM1
Authors: Marx Christopher J. , Chistoserdova Ludmila , Lidstrom Mary E.
Published: December 2003

The
facultative methylotroph
Methylobacterium extorquens
AM1
possesses two pterin-dependent pathways for C
1
transfer
between formaldehyde and formate, the tetrahydrofolate
(H
4
F)-linked pathway and the tetrahydromethanopterin
(H
4
MPT)-linked pathway. Both pathways are required for
growth on C
1
substrates; however, mutants defective for the
H
4
MPT pathway reveal a unique phenotype of being inhibited
by methanol during growth on multicarbon compounds such as succinate.
It has been previously proposed that this methanol-sensitive phenotype
is due to the inability to effectively detoxify formaldehyde produced
from methanol. Here we present a comparative physiological
characterization of four mutants defective in the H
4
MPT
pathway and place them into three different phenotypic classes that are
concordant with the biochemical roles of the respective enzymes. We
demonstrate that the analogous H
4
F pathway present in
M.
extorquens
AM1 cannot fulfill the formaldehyde detoxification
function, while a heterologously expressed pathway linked to
glutathione and NAD
+
can successfully substitute for
the H
4
MPT pathway. Additionally, null mutants were generated
in genes previously thought to be essential, indicating that the
H
4
MPT pathway is not absolutely required during growth on
multicarbon compounds. These results define the role of the
H
4
MPT pathway as the primary formaldehyde oxidation and
detoxification pathway in
M. extorquens
AM1.
Development ofa Physical and Genetic Map of the VirulentWolbachiaStrainwMelPop
Authors: Sun Ling V. , Riegler Markus , O'Neill Scott L.
Published: December 2003

We report here the construction of a physical and genetic map of the virulentWolbachiastrain,wMelPop. This map was determined by ordering 28 chromosome fragments that resulted from digestion with the restriction endonucleasesFseI,ApaI,SmaI, andAscI and were resolved by pulsed-field gel electrophoresis. Southern hybridization was done with 53Wolbachia-specific genes as probes in order to determine the relative positions of these restriction fragments and use them to serve as markers. Comparison of the resulting map with the whole genome sequence of the closely related benignWolbachiastrain,wMel, shows that the two genomes are largely conserved in gene organization with the exception of a single inversion in the chromosome.