bluuebunny/crossref_metadata_2025 huggingface dataset:
An Empirical Test of the Relative Validity of Expert and Lay Judgments of Risk
Authors: Wright George , Bolger Fergus , Rowe Gene
Published: March 2003

This article investigates how accurately experts (underwriters) and lay persons (university students) judge the risks posed by life‐threatening events. Only one prior study (Slovic, Fischhoff, & Lichtenstein, 1985) has previously investigated the veracity of expert versus lay judgments of the magnitude of risk. In that study, a heterogeneous grouping of 15 experts was found to judge, using marginal estimations, a variety of risks as closer to the true annual frequencies of death than convenience samples of the lay population. In this study, we use a larger, homogenous sample of experts performing an ecologically valid task. We also ask our respondents to assess frequencies and relative frequencies directly, rather than ask for a “risk” estimate—a response mode subject to possible qualitative attributions—as was done in the Slovic et al. study. Although we find that the experts outperformed lay persons on a number of measures, the differences are small, and both groups showed similar global biases in terms of: (1) overestimating the likelihood of dying from a condition (marginal probability) and of dying from a condition given that it happens to you (conditional probability), and (2) underestimating the ratios of marginal and conditional likelihoods between pairs of potentially lethal events. In spite of these scaling problems, both groups showed quite good performance in ordering the lethal events in terms of marginal and conditional likelihoods. We discuss the nature of expertise using a framework developed by Bolger and Wright (1994), and consider whether the commonsense assumption of the superiority of expert risk assessors in making magnitude judgments of risk is, in fact, sensible.
Growth and Heat Resistance Kinetic Variation Among Various Isolates of Salmonella and its Application to Risk Assessment
Authors: Juneja Vijay K. , Marks Harry M. , Huang Lihan
Published: March 2003

The abilities of cells of a particular type of bacteria to leave lag phase and begin the process of dividing or surviving heat treatment can depend on the serotypes or strains of the bacteria. This article reports an investigation of serotype‐specific differences in growth and heat resistance kinetics of clinical and food isolates of Salmonella. Growth kinetics at 19°C and 37°C were examined in brain heart infusion broth and heat resistance kinetics for 60°C were examined in beef gravy using a submerged coil heating apparatus. Estimates of the parameters of the growth curves suggests a small between‐serotype variance of the growth kinetics. However, for inactivation, the results suggest a significant between‐serotype effect on the asymptotic D‐values, with an estimated between‐serotype CV of about 20%. In microbial risk assessment, predictive microbiology is used to estimate growth and inactivation of pathogens. Often the data used for estimating the growth or inactivation kinetics are based on measurements on a cocktail—a mixture of approximately equal proportions of several serotypes or strains of the pathogen being studied. The expected growth or inactivation rates derived from data using cocktails are biased, reflecting the characteristics of the fastest growing or most heat resistant serotype of the cocktail. In this article, an adjustment to decrease this possible bias in a risk assessment is offered. The article also presents discussion of the effect on estimating growth when stochastic assumptions are incorporated in the model. In particular, equations describing the variation of relative growth are derived, accounting for the stochastic variations of the division of cells. For small numbers of cells, the expected value of the relative growth is not an appropriate “representative” value for actual relative growths that might occur.
Implications of Social Security Reform on Interest Rates: Theory and Evidence
Authors: Elder Erick , Holland Larry
Published: March 2003

This article investigates the potential effect that Social Security reform may have on bond and equity returns. We specifically focus on the effect of proposals to shift a portion of the investment of the U.S. Social Security Trust Fund to the equities market. Models are developed to demonstrate the relationship between returns and both the relative size of the Social Security Trust Fund and the portfolio allocation of the Trust Fund. Using these two models, we then show that interest rates will increase from either a decrease in the size of the Social Security Trust Fund or a shifting in the investment mix from bonds to equities. We derive an adjustment factor that relates the magnitude of change in interest rates from either source and use this adjustment factor in conjunction with estimates of the relationship between government debt and interest rates to forecast the potential effect on interest rates from shifting part of the Trust Fund to the equity market. The estimates herein suggest that investing some of the Social Security funds in equities is not a painless cure‐all for the Social Security system and may even have some adverse effects in terms of income transfers from American taxpayers to foreign bondholders.
Equilibrium Price Dispersion in the Insurance Market
Authors: Hun Seog S.
Published: March 2003

We consider price dispersion under nonsequential consumer search when a finite number of firms exists. We assume that firms have the same production technology. We find that single‐price equilibrium exists only when it is the highest possible price (monopoly price). Price dispersion is possible in equilibrium only when firms use mixed strategies. We also find that increased competition may increase price dispersion and the intensity of consumer search while reducing the expected profits of firms. The number of firms in the long run is increasing regarding expected market demand and decreasing regarding production cost and entry cost. We reinterpret some empirical observations reported in the literature.
Community Involvement: Theoretical Approaches and Educational Initiatives
Authors: Stukas Arthur A. , Dunlap Michelle R.
Published: March 2003

Efforts to increase involvement of citizens in their communities are now widespread. We discuss key forms of community involvement, such as community service and volunteerism, broadly, and educational initiatives that promote involvement (e.g., service–learning courses) more specifically. There are benefits to be achieved by the promotion of involvement, but also potential drawbacks. As an example of one approach to investigating community involvement, we review research on the interactive influence of person–centered functional variables (e.g., motives) and situation–centered structural variables (e.g., program features) on prosocial action. Ultimately, we call for greater attention to be paid to all of the constituent groups in the community involvement spectrum and the necessarily respectful and equitable relationships that must be forged among them.
The Omnipresent Classroom during Summer Study Abroad: American Students in Conversation with Their French Hosts
Authors: Wilkinson Sharon
Published: March 2003

Study abroad is often promoted as one of the best opportunities to use foreign language skills outside the classroom. Yet, relatively little is known about the language that students produce when speaking in noninstructional settings. Relying on conversation analysis and ethnographic techniques, this qualitative study investigates both speech and speaker perceptions through tape–recorded conversations between summer study abroad students and their French hosts, as well as through interviews and observations. Findings indicate that natives and nonnatives alike relied heavily on classroom roles and discourse structures to manage their interactions, calling into question the assumption that language use with a native–speaking host family liberates students from classroom limitations. The inappropriateness of transferring didactic discourse patterns to out–of–class interactions also raises issues for consideration about the nature of in–class instructional practices.
The Role of Reflective Conversations and Feedback in Helping Preservice Teachers Learn to Use Cooperative Activities in their Second Language Classrooms
Authors: Gwyn–Paquette Caroline , Tochon François Victor
Published: March 2003

The object of this qualitative study was to examine how preservice second language teachers navigate through the difficulties of introducing cooperative learning into their classrooms during student teaching, despite the fact that this approach differs from their cooperating teachers’ customary teaching strategy. We sought to determine what helps or inhibits the student teachers’ progress. Although convictions about the usefulness of the cooperative approach and other personal motivation provided the springboard for experimentation, it became evident from the analysis of supervisory conversations that expert coaching and continuous moral support are essential to foster the development of the preservice teachers’ ability to innovate in their teaching approach. In the absence of informed in–school support, expert help is needed from outside the school. Under these conditions, the university supervisor becomes a central player in the preservice teacher’s construction of knowledge about cooperative learning.
Timing and Intensity of Tutoring: A Closer Look at the Conditions for Effective Early Literacy Tutoring
Authors: Vadasy Patricia F. , Sanders Elizabeth A. , Peyton Julia A. , Jenkins Joseph R.
Published: March 2003

In this article we report data from a longitudinal study of one–to–one tutoring for students at risk for reading disabilities. Participants were at–risk students who received phonics–based tutoring in first grade, students who were tutored in comprehension skills in second grade, and students tutored in both grades 1 and 2. At second–grade posttest, there were significant differences in word identification and word attack between students who were tutored in first grade only compared to students who were also tutored in second grade, favoring students who were tutored in first grade only. Overall, there were no advantages to a second year of tutoring. For students tutored in second grade only, there were no differences at second–grade posttest compared to controls. Schools may have selected students who did not respond to first–grade tutoring for continued tutoring in second grade. Findings are discussed in light of decisions schools make when using tutors to supplement reading instruction for students with reading difficulties.
Capital Financing of Schools: A Comparison of Lease Purchase Revenue Bonds and General Obligation Bonds
Authors: Gamkhar Sahma , Koerner Mona
Published: March 2003

School building construction is on the rise nationwide and Texas has led the nation in outlays on school construction. We consider key factors that distinguish lease purchase revenue (LPR) bonds and general obligation (GO) bonds as debt instruments for financing school facilities in Texas. Our research shows that LPR bonds typically have a higher interest cost than GO bonds and they do not have any advantages over GO bonds in circumventing state restrictions on school district tax and debt authority. Voter approval requirements implicit in the state aid formulae supporting school bond repayments and the bond election requirements are however both less stringent in the case of LPR bonds than GO bonds.
Testing Rival Decision–Making Theories on Budget Outputs: Theories and Comparative Evidence
Authors: Reddick Christopher G.
Published: March 2003

This study demonstrates the link between the degree of economic rationality and budgetary decision–making outputs for Canada, the United Kingdom, and the United States. Three empirical models are derived with low, intermediate, and high degrees of economic rationality, namely, “garbage can,” incrementalism, and rational choice budgeting, respectively. The methods used are time series analyses on real disaggregated national government budget outputs for the post–World War II period for Canada, the United States, and the United Kingdom. There was some support found for budgetary incrementalism, and the most consistent support for rational choice budgeting. There was no support for garbage can budgeting.
Ukrainian Local Governments’ Finance on the Threshold of a New Millenium: Will Interbudgetary Reform Meet Public Needs?
Authors: Slukhai Sergii
Published: March 2003

Since independence, market–oriented reforms have been undertaken in Ukraine. Yet, intergovernmental relations are obsolete, remaining as they were in the Soviet time. In fact, Ukrainian subcentral governments have no significant discretion in revenues and expenditures. First, the article delivers an overview of the current system of intergovernmental finance in Ukraine. Second, the article reveals some negative trends in Ukrainian local governments’ fiscal performance through the late 1990s that made a reform of intergovernmental fiscal arrangements timely. Third, the article analyzes recent reform steps as presented by the recent Budget Code, proposing policy options that could strengthen Ukrainian intergovernmental policy.
Politics, Public Opinion, and Privatization in France: Assessing the Calculus of Consent for Market Reforms
Authors: Durant Robert F. , Legge, Jr. Jerome S.
Published: March 2003

Despite the normative, political, and instrumental importance of privatizing state‐owned enterprises worldwide, practitioners and researchers know little empirically about how different types of citizens feel about these efforts, how they arrive at these judgments, and how enduring these attitudes are likely to be. Using citizen attitudes toward privatization culled from the 1995 French National Election Study, this article offers practitioners and researchers an analytical framework for assessing these attitudes, for anticipating and dealing strategically with the perceived consequences of denationalization efforts, and for refining their understanding of the calculus of consent for market reforms in future survey research.
Reconciling Environmental Ethics and Political Values
Authors: Reed Christine M.
Published: March 2003

Book reviewed in this article:

Peter S. Wenz, Environmental Ethics Today
Homeland Security: The Difference between a Vision and a Wish
Authors: Donley Michael B. , Pollard Neal A.
Published: March 2003

The U.S. government is considering how it should reorganize for homeland security. Consequently, attention has focused on the new Office of Homeland Security (OHS). Much debate focuses on two issues related to OHS: (1) whether the OHS should be a separate executive agency; and (2) whether the OHS director has sufficient authority to direct changes in policies and resource allocation of other departments and agencies. The authors believe the emphasis on these areas of interest is misplaced as measures of the eventual success of the OHS. Rather than focusing on these political issues, this article outlines several questions about how the OHS might approach its complex mission and highlights some organizational and bureaucratic realities that are likely to survive the debate over placement of the OHS within the executive branch and the authorities of the OHS director. This article concludes with a discussion of some organizational tools that the OHS or any coordinating office will require to fulfill its mandate.
A Dynamic Double‐Trigger Model of Multifamily Mortgage Default
Authors: Goldberg Lawrence , Capone, Jr. Charles A.
Published: March 2003

This study advances the commercial mortgage literature by providing theory and methods for incorporating both equity and cash‐flow considerations in default models. We use local market conditions to compute a (joint) probability that default is in‐the‐money, based on both equity and cash‐flow considerations. Statistical analysis is performed using data on multifamily mortgages originated in the 1980s and early 1990s. Simulations based on statistical modeling show advantages of the probabilistic double‐trigger approach over other measures of equity and cash flow.
Authors’ Perceptions and Preferences Among Real Estate Journals
Authors: Gibler Karen M. , Ziobrowski Alan J.
Published: March 2003

Journal editors who want to attract the best research must understand authors’ perceptions of their journals. In this survey, U.S. academic authors rank Real Estate Economics (REE) higher than The Journal of Real Estate Finance and Economics (JREFE) and rank The Journal of Real Estate Research (JRER) third. Authors perceive REE as high quality with promotion and tenure value and JREFE as providing a fair, efficient publication process. Faculty at doctoral degree‐granting schools are more discerning between the journals, whereas faculty at schools with real estate degree programs are more likely to have work in all three journals rewarded. Publishing in a journal and membership in a real estate association also influence opinions.
Ex Ante Costs of Violating Absolute Priority in Bankruptcy
Authors: Bebchuk Lucian Arye
Published: March 2003

A basic question for the design of bankruptcy law concerns whether value should be divided in accordance with absolute priority. Research done in the past decade has suggested that deviations from absolute priority have beneficial ex ante effects. In contrast, this paper shows that ex post deviations from absolute priority also have negative effects on ex ante decisions taken by shareholders. Such deviations aggravate the moral hazard problem with respect to project choice‐increasing the equityholders incentive to favor risky projects‐as well as with respect to borrowing and dividend decisions.
Limited Arbitrage in Equity Markets
Authors: Mitchell Mark , Pulvino Todd , Stafford Erik
Published: March 2003

We examine 82 situations where the market value of a company is less than its subsidiary. These situations imply arbitrage opportunities, providing an ideal setting to study the risks and market frictions that prevent arbitrageurs from immediately forcing prices to fundamental values. For 30 percent of the sample, the link between the parent and its subsidiary is severed before the relative value discrepancy is corrected. Furthermore, returns to a specialized arbitrageur would be 50 percent larger if the path to convergence was smooth rather than as observed. Uncertainty about the distribution of returns and characteristics of the risks limits arbitrage.
Managerial Opportunism? Evidence from Directors' and Officers' Insurance Purchases
Authors: Chalmers John M. R. , Dann Larry Y. , Harford Jarrad
Published: March 2003

We analyze a sample of 72 IPO firms that went public between 1992 and 1996 for which we have detailed proprietary information about the amount and cost of D&O liability insurance. If managers of IPO firms are exploiting superior inside information, we hypothesize that the amount of insurance coverage chosen will be related to the post‐offering performance of the issuing firm's shares. Consistent with the hypothesis, we find a significant negative relation between the three‐year post‐IPO stock price performance and the insurance coverage purchased in conjunction with the IPO. One plausible interpretation is that, like insider securities transactions, D&O insurance decisions reveal opportunistic behavior by managers. This provides some motivation to argue that disclosure of the details of D&O insurance decisions, as is required in some other countries, is valuable.
Equilibrium Pricing and Optimal Hedging in Electricity Forward Markets
Authors: Bessembinder Hendrik , Lemmon Michael L.
Published: March 2003

Spot power prices are volatile and since electricity cannot be economically stored, familiar arbitrage‐based methods are not applicable for pricing power derivative contracts. This paper presents an equilibrium model implying that the forward power price is a downward biased predictor of the future spot price if expected power demand is low and demand risk is moderate. However, the equilibrium forward premium increases when either expected demand or demand variance is high, because of positive skewness in the spot power price distribution. Preliminary empirical evidence indicates that the premium in forward power prices is greatest during the summer months.
Rational Asset Prices
Authors: Constantinides George M.
Published: March 2003

The mean, covariability, and predictability of the return of different classes of financial assets challenge the rational economic model for an explanation. The unconditional mean aggregate equity premium is almost seven percent per year and remains high after adjusting downwards the sample mean premium by introducing prior beliefs about the stationarity of the price–dividend ratio and the (non)forecastability of the long‐term dividend growth and price—dividend ratio. Recognition that idiosyncratic income shocks are uninsurable and concentrated in recessions contributes toward an explanation. Also borrowing constraints over the investors' life cycle that shift the stock market risk to the saving middle‐aged consumers contribute toward an explanation.
Telling from Discrete Data Whether the Underlying Continuous‐Time Model Is a Diffusion
Authors: Aït‐Sahalia Yacine
Published: March 2003

Can discretely sampled financial data help us decide which continuous‐time models are sensible? Diffusion processes are characterized by the continuity of their sample paths. This cannot be verified from the discrete sample path: Even if the underlying path were continuous, data sampled at discrete times will always appear as a succession of jumps. Instead, I rely on the transition density to determine whether the discontinuities observed are the result of the discreteness of sampling, or rather evidence of genuine jump dynamics for the underlying continuous‐time process. I then focus on the implications of this approach for option pricing models.
Learning about Internal Capital Markets from Corporate Spin‐offs
Authors: Gertner Robert , Powers Eric , Scharfstein David
Published: March 2003

We examine the investment behavior of firms before and after being spun off from their parent companies. Their investment after the spin‐off is significantly more sensitive to measures of investment opportunities (e.g., industry Tobin's Q or industry investment) than it is before the spin‐off. Spin‐offs tend to cut investment in low Q industries and increase investment in high Q industries. These changes are observed primarily in spin‐offs of firms in industries unrelated to the parents' industries and in spin‐offs where the stock market reacts favorably to the spin‐off announcement. Our findings suggest that spin‐offs may improve the allocation of capital.
Organization of the Vesicular Stomatitis Virus Glycoprotein into Membrane Microdomains Occurs Independently of Intracellular Viral Components
Authors: Brown Erica L. , Lyles Douglas S.
Published: March 2003

The glycoprotein (G protein) of vesicular stomatitis virus (VSV) is primarily organized in plasma membranes of infected cells into membrane microdomains with diameters of 100 to 150 nm, with smaller amounts organized into microdomains of larger sizes. This organization has been observed in areas of the infected-cell plasma membrane that are outside of virus budding sites as well as in the envelopes of budding virions. These observations raise the question of whether the intracellular virion components play a role in organizing the G protein into membrane microdomains. Immunogold-labeling electron microscopy was used to analyze the distribution of the G protein in arbitrarily chosen areas of plasma membranes of transfected cells that expressed the G protein in the absence of other viral components. Similar to the results with virus-infected cells, the G protein was organized predominantly into membrane microdomains with diameters of approximately 100 to 150 nm. These results indicate that internal virion components are not required to concentrate the G protein into membrane microdomains with a density similar to that of virus envelopes. To determine if interactions between the G protein cytoplasmic domain and internal virion components were required to create a virus budding site, cells infected with recombinant VSVs encoding truncation mutations of the G protein cytoplasmic domain were analyzed by immunogold-labeling electron microscopy. Deletion of the cytoplasmic domain of the G protein did not alter its partitioning into the 100- to 150-nm microdomains, nor did it affect the incorporation of the G protein into virus envelopes. These data support a model for virus assembly in which the G protein has the inherent property of partitioning into membrane microdomains that then serve as the sites of assembly of internal virion components.
Cytoskeletal Requirements for Hepatitis C Virus (HCV) RNA Synthesis in the HCV Replicon Cell Culture System
Authors: Bost Anne G. , Venable Daryl , Liu Lifei , Heinz Beverly A.
Published: March 2003

Hepatitis C virus (HCV) induces microtubule aggregates in infected hepatocytes. To determine if cytoskeletal elements are important for HCV RNA synthesis, we examined the effect of cytoskeleton inhibitors on HCV replicon transcription in Huh7 cells. The data demonstrate that HCV replication complex-mediated RNA synthesis requires microtubule and actin polymerization.
ON THE ESTIMATION OF THE CURRENT VALUE OF THE COSMOLOGICAL CONSTANT
Authors: GURZADYAN V. G. , XUE SHE-SHENG
Published: March 2003

We advance the viewpoint that, only relevant modes of the vacuum fluctuations, namely, with wavelengths conditioned by the size, homogeneity, geometry and topology of the Universe, do contribute to the cosmological constant. A formula is derived which relates the cosmological constant with the size of the Universe and the three fundamental constants: the velocity of light, Planck and Newton gravitational constants. Then the current value of the cosmological constant remarkably agrees with the value indicated by distant supernovae observations, i.e. of the order of the critical density. Thus the cosmological constant had to be smaller than the matter density in the past and will be bigger in the future.
ANALYTICAL CALCULATION OF MATTER EFFECTS IN TWO MASS-SCALE NEUTRINO OSCILLATIONS
Authors: NARAYAN MOHAN , SANKAR S. UMA
Published: March 2003

We consider three active flavor neutrino oscillations where both the mass-square differences play a role in atmospheric neutrino problem. We calculate the matter effects arising due to propagation through earth. We demonstrate that these effects improve the fit to the electron data vis-a-vis vacuum oscillations but make the fit to the muon data far worse, thus worsening the overall fit. The results of our analytical calculation verify the numerical investigations of this scheme presented earlier by Fogli et al.
SPECTROSCOPY AND CONFINEMENT
Authors: Olsson M. G.
Published: March 2003

In this talk I progress semi-historically from the potential model as applied to heavy onia states to the QCD string dynamics of light quark mesons. The virtues and problems of the potential model are reviewed. Some of the difficulties are solved by the introduction of QCD string confinement. The method of solving string models numerically is outlined and some recent analytic results are discussed. We end by exploring some consequences of the model and how the observed light quark mesons can be classified simply.
CHIRAL UNITARY APPROACH TO HADRON SPECTROSCOPY
Authors: Oset E. , Inoue T. , Vicente Vacas M. J. , Ramos A. , Bennhold C.
Published: March 2003

The s-wave meson-baryon interaction in the S = -1, S = 0 and S = -2 sectors is studied by means of coupled channels, using the lowest-order chiral Lagrangian and the N/D method or equivalently the Bethe-Salpeter equation to implement unitarity. This chiral approach leads to the dynamical generation of the Λ(1405), Λ(1670) and Σ(1620) states for S = -1, the N*(1535) for S = 0 and the Ξ(1620) for S = -2. We look for poles in the complex plane and extract the couplings of the resonances to the different final states. This allows identifying the Λ(1405) and the Λ(1670) resonances with [Formula: see text] and K Ξ quasibound states, respectively. Our results are found to be incompatible with the measured properties of the Ξ(1690) resonance, thus ruling this state out as the remaining member of this octet of dynamically generated resonances. We therefore assign 1/2- for the spin and parity of the Ξ(1620) resonance as the S = -2 member of the lowest-lying 1/2- octet.
COVARIANT HELICITY-COUPLING AMPLITUDES: PRINCIPLES AND EXAMPLES
Authors: Chung Suh-Urk
Published: March 2003

A general formulation has been given for constructing covariant helicity-coupling amplitudes involving two-body decays with arbitrary integer spins. In order to illustrate the principles, the case of a spin-1 object decaying into spin-2 and spin-1 particles is treated in some detail. Also given are the helicity-coupling amplitudes for a spin-2 object decaying into a spin-2 and a spin-0 particle.
COMBINING DATA SETS IN A PARTIAL WAVE ANALYSIS
Authors: Thoma Ulrike
Published: March 2003

Partial wave analyses are often done to extract resonance parameters from data. Using analyses of data from the Crystal Barrel Experiment (LEAR) as an example, it will be shown that this can be done with higher reliability and precision if different data sets containing related information are combined in one analysis.
THE PRICE SENSITIVITY OF BUSINESS SERVICE OUTSOURCING ANNOUNCEMENTS BY UK COMPANIES
Authors: JUMA'H AHMAD H. , WOOD DOUGLAS
Published: March 2003

This article investigates the market reaction to a sample of announcements of business service outsourcing arrangements made by UK quoted companies between 1991 and 1997. Event study methodology is applied to daily stock returns to measure the reaction, in the form of excess returns, immediately prior to and at the date of an outsourcing contract announcement. The conclusion is that initial announcements tend to enjoy positive and significant reaction and that the larger companies in the sample show a more positive reaction than smaller companies. Overall outsourcing announcements appear to be associated with excess returns but the absence of any recognized basis for disclosure prevents a complete analysis of such events.
Identification of a novel HLA‐C allele, Cw*0406, in a Singapore Malay
Authors: Ren E.C. , Haniff F. , Loh M.T. , Chan S.H. , Petersdorf E. , Hansen J.
Published: March 2003

A novel allele, C*0406 1, has been identified and is characterised by a single nucleotide substitution at position 196 of exon 3 when compared with its closest related allele, C*0403. The latter is found in 4/69 Chinese and 7/80 Malays while Cw*0406 was found in only one Malay individual within the study populations. The data suggest that Cw*0406 may have arisen as a relatively recent genetic event either by gene conversion or as a simple point mutation variant of Cw*0403.
Susceptibility to ankylosing spondylitis is independent of the Bw4 and Bw6 epitopes of HLA‐B27 alleles
Authors: Armas J.B. , Gonzalez S. , Martinez‐Borra J. , Laranjeira F. , Ribeiro E. , Correia J. , Ferreira M.L. , Toste M. , López‐Vazquez A. , López‐Larrea C.
Published: March 2003

We have characterized HLA‐B27 alleles in a sample of the population from the Azores (n=46) with the aim of investigating the contribution of different subtypes to ankylosing spondylitis (AS). The study was carried out using PCR‐SSOP and in some samples genomic sequencing was conducted. Some significant new finding have arisen from this study. First, B*2705,B*2702,B*2703,B*2707 and B*2708 alleles were found to be represented in this population. The polymorphism of B27 alleles found in a sample of the population from the Azores is higher than the Caucasian groups described. B*2703 and B*2707 have not previously been described to be represented in Caucasians and this could indicate admixtures with different populations of the world. In addition, the B*2708 allele was found to be associated with AS in a large family from the Azores. This association has not been previously reported in either ethnic group and needs to be confirmed in other population studies. This is of considerable interest since has only been described as a rare subtype underrepresented in the British population and has not been previously found to be associated with AS. B*2708 carries the sequence specifying the Bw6 epitope in contrast to most B27 alleles which carry a Bw4 sequence. Differences in this region (residues 77–83) can alter the F‐pocket and affect T‐cell recognition. The importance that these molecular changes can play in the pathogenesis of AS is discussed.

“Thus far, O Portuguese, it is granted to you to glimpse into the future and to know the exploits that await your stout‐hearted compatriots on the ocean that, thanks is now no longer unknown”.

The Lusiads (L. Camoes)
New polymorphic microsatellite markers in the human MHC class I region
Authors: Tamiya G. , Shiina T. , Oka A. , Tomizawa M. , Ota M. , Katsuyama Y. , Yoshitome M. , Makino S. , Kimura M. , Inoko H.
Published: March 2003

The human major histocompatibility complex (MHC) class I region is believed to contain a large number of genes encoding susceptible factors for diseases such as Behçet’s disease, Graves disease and psoriasis vulgaris. To identify the causative genes of those diseases, we have conducted large‐scale genomic sequencing and determined the 1.8 Mb entire HLA class I region from the MICB gene to the HLA‐F gene. During the course of genomic sequencing, a total of 731 microsatellite sequences with dinucleotide to pentanucleotide repeats were found in this region. Previously, we reported that 26 microsatellites between MICB and S on the most centromeric side of the class I region, and between HSR1 and HLA‐92/L in the midst of the class I region were highly polymorphic, and served as excellent genetic markers. In this paper, in order to fill the gaps with no known polymorphic microsatellites available in the HLA class I region, 12 new polymorphic microsatellite markers were recruited from the 1.8 Mb region including the remaining class I segments, namely between S and HSR1, and between HLA‐92/L and HLA‐F. The average number of alleles at these new microsatellite loci was 8.2 with a polymorphism content value (PIC) of 0.63. These 38 markers in total almost uniformly interspersed in the HLA class I region will enable us to search precisely for the location of disease susceptible loci within the HLA class I region by association and for linkage analyses.
HLA and tumour necrosis factor (TNF) polymorphisms in ocular Behçet’s disease
Authors: Verity D.H. , Wallace G.R. , Vaughan R.W. , Kondeatis E. , Madanat W. , Zureikat H. , Fayyad F. , Marr J.E. , Kanawati C.A. , Stanford M.R.
Published: March 2003

The role of HLA‐B*51 and other major histocompatibility complex (MHC) genes in Behçet’s disease (BD) remains unknown. We have performed HLA and tumour necrosis factor (TNF) polymorphism analysis in BD and evaluated their contribution to ocular disease. In this study, 102 patients and 115 controls of Middle Eastern descent were investigated by HLA and B*51 subtyping using novel primers, and by LT αNCo 1 and TNF –308 promoter polymorphism analysis. The frequency of the HLA‐B*51 family of alleles was raised in patients compared to controls (66% vs. 15%, Pc=2.5×10−12, OR=10.9). The odds ratio (OR) of this group of alleles for subgroups of patients was as follows: non‐ocular patients 7.8, all ocular patients 12.6, blind patients >22. HLA‐B*51 subtyping detected B*5101, 07, 08 and 09 alleles, with a similar frequency among patients and controls. HLA‐Cw*1602 was associated with B*5108, but was not an independent risk factor for disease. The LT α (TNFB*2) allele was associated with HLA‐B*51 among patients and the frequency of this allele was significantly higher among completely blind patients compared to both non‐ocular patients (P=0.048, OR >3.6) and to healthy controls (P=0.022, OR >4.3). The rare TNF‐2 polymorphism at the TNF –308 promoter position was associated with HLA‐B*50 (not B*51), and was not associated with BD. Thus, in this population the HLA*B51 family of alleles is a strong risk factor for BD, and in particular the development of ocular disease. HLA‐B*51 subtyping did not define new markers for BD. A primary role for TNF gne polymorphisms in BD was not identified, but co‐expression of the TNFB*2 allele with HLA‐B*51 may contribute to severity of ocular disease.
α‐interferon treatment induces quantitative modifications of HLA class I‐associated peptides eluted from cultured cancer cell lines
Authors: Cangemi G. , Millo E. , Damonte G. , Semino C. , Pietra G. , Benatti U. , Melioli G.
Published: March 2003

Interferons upregulate the expression of HLA class I antigens on cancer cells. Nevertheless, little is known about the panel of HLA class I antigen‐associated peptides presented by recombinant α‐interferon (rα‐IFN)‐treated cells. For this reason, peptides were eluted from five cancer cell lines (four melanoma and one non‐small cell lung cancer) following treatment with rα‐IFN. High‐performance liquid chromatography (HPLC) profiles of the peptide fractions were compared with those obtained from untreated cells. No significant differences in peptide characteristics (detectable on the basis of retention times) were observed, but significant differences in terms of peptide quantities were observed. Mass spectrometry performed on HPLC peaks allowed not only the detection of three different peptides (two derived from the MAGE family of genes and one from the mart‐1) both in untreated and in treated cells, but also gave an indication of the number of peptides within one HPLC peak. This data demonstrates that rα‐IFN‐treated cells express a similar peptide pattern as untreated cells, with significant quantitative differences. Interestingly, this finding also explains the higher susceptibility to lysis (mediated by specific cytolytic lymphocytes, which recognize cancer cells in an HLA‐restricted fashion) of rα‐IFN‐treated cells.
Different gene loci within the HLA‐DR and TNF regions are independently associated with susceptibility and severity in Spanish rheumatoid arthritis patients
Authors: Hajeer A.H. , Dababneh A. , Makki R.F. , Thomson W. , Poulton K. , González‐Gay M.A. , García‐Porrúa C. , Mattey D.L. , Ollier W.E.R.
Published: March 2003

The aim of this study was to investigate whether polymorphisms in the tumor necrosis factor (TNF) and HLA‐DRB1 gene regions are independently associated with rheumatoid arthritis (RA) in a population from Lugo region of northwestern Spain. RA patients (n=179) attending hospital outpatient clinics in Lugo, northwestern Spain and matched controls (n=145) were recruited. RA susceptibility in this population was predominantly associated with DRB1*0401, while erosive disease was associated with HLA‐DRB1*0101 and DRB1*04. The increase in DRB1*04 was accounted for by an increase in DRB1*0404 and *0405 but not *0401 frequencies. In contrast, *0401 frequency was significantly increased in seropositive patients. The rheumatoid arthiritis shared epitope (SE) was associated with increased risk for seropositive and erosive disease and this appeared to operate in a dose‐dependent manner. Logistic regression analyses revealed that the TNF microsatellite markers TNFc1 and b3 were associated with RA independently of DRB1*04 and the SE. Carriage of a TNF c1 allele provided an increased risk of RA in SE‐negative and SE‐heterozygous individuals. TNFc1 and TNFb3 were not associated with erosive or seropositive disease. In contrast, TNF a2 was significantly associated with erosive disease which was independent of DRB1*04 and the SE. Further studies will be needed to establish why (TNFc1) polymorphism seemingly associated with low TNFα production, is a risk factor for RA.
Identification of a new HLA‐DRB4 allele (DRB4*01033) by PCR‐SSP and direct sequencing
Authors: Palou E. , Nogués N. , Gil J. , Ribera A.
Published: March 2003

In this report, we describe the identification of a novel DRB4*01 allele, DRB4*01033, found in two Spanish Caucasian individuals. The new allele was detected during routine HLA typing by an unusual pattern of amplification obtained by polymerase chain reaction using sequence‐specific primers (PCR‐SSP) that did not match with any of the previously described DRB4 alleles. In order to establish the polymorphism responsible for this pattern exons 2 and 3 of the DRB4 locus were amplified and directly sequenced. The new DRB4*01 allele is identical to DRB4*0103101 except for a single nucleotide substitution in codon 78 (TAC→TAT). This nucleotide change does not cause an amino acid change as both triplets code for a tyrosine ( Note).
HLA class I and class II allele distribution in the Peruvian population
Authors: De Pablo R. , Beraún Y. , Nieto A. , Calzada J.E. , Rementería M.C. , Sanz L. , López‐Nevot M.A. , Martín J.
Published: March 2003

The distribution of HLA‐A, ‐B, ‐C, ‐DRB1 and ‐DQB1 alleles in the Peruvian population was studied and compared with those of other populations in order to provide further information about their anthropological origin. Our data are consistent with the Mestizo character of this population. In terms of genetic distance Peruvians are closest to Bolivians, which is in agreement with the geographical location and the cultural and anthropological background of the two human groups. Several HLA‐B alleles originally described in genetically isolated Amerindian tribes are also present in the sample studied here. This fact and the reported finding of these alleles in several Amerindian groups suggests that they were present in the first wave of humans that populated South America (Paleoindians) before they split to give rise to the different South American tribes.
Lack of HLA‐class I antigens in human neuroblastoma cells: analysis of its relationship to TAP and tapasin expression
Authors: Corrias M.V. , Occhino M. , Croce M. , De Ambrosis A. , Pistillo M.P. , Bocca P. , Pistoia V. , Ferrini S.
Published: March 2003

Abstract: We studied the constitutive and the interferon (IFN)‐γ‐induced expression of HLA class I antigen heavy chain, β2‐microglobulin (β2m), TAP‐1, TAP‐2 and tapasin in a panel of eleven neuroblastoma cell lines. Surface expression of HLA class I antigens was low in eight out of eight neuroblastoma cell lines bearing MYC‐N amplification and/or 1p deletion, while two out of three neuroblastoma cell lines lacking these genetic alterations showed normal expression. IFN‐γ treatment restored HLA class I antigen surface expression in all neuroblastoma cell lines. Eight out of 11 neuroblastoma cell lines did not express TAP‐1 mRNA and three of them also lacked TAP‐2 mRNA. β2 m mRNA was barely detectable or absent in five neuroblastoma cell lines, while tapasin mRNA was always expressed. IFN‐γ upregulated the expression of HLA class I heavy chain, β2 m, TAP‐1, TAP‐2 and tapasin, as detected at mRNA or protein level. Post‐transcriptional events were involved in altered TAP‐1 and β2 m expression in one peculiar neuroblastoma cell line. These data indicate that multiple mechanisms play a role in the HLA class I antigen‐deficient phenotype of human neuroblastoma.
HLA class I in three West African ethnic groups: genetic distances from sub‐Saharan and Caucasoid populations
Authors: Modiano D. , Luoni G. , Petrarca V. , Sodiomon Sirima B. , De Luca M. , Simporé J. , Coluzzi M. , Bodmer J. G. , Modiano G.
Published: March 2003

Abstract: Fulani of Burkina Faso (West Africa) are a particularly interesting ethnic group because of their lower susceptibility to Plasmodium falciparum malaria as compared to sympatric populations, Mossi and Rimaibé. Moreover, the occurrence of a Caucasoid component in their genetic make‐up has been suggested on the basis of their physical traits and cultural traditions even though this view was not supported by genetic studies. A total of 149 unrelated subjects (53 Mossi, 47 Rimaibé and 49 Fulani) have been typed for 97 HLA class I alleles with the amplification refractory mutation system/polymerase chain reaction (ARMS/PCR) technique. Mossi and Rimaibé data were pooled since none of the 42 statistically testable alleles exhibited a significant heterogeneity. These pooled gene frequencies were found to be very different from those of Fulani: a certain (P<0.001) or a likely (0.001 <P<0.01) difference was found for 5 and 12 alleles, respectively. Four alleles (A*24, A*29, B*27, B*3701) appeared to be essentially “private” Fulani alleles with respect to the other two populations but their presence was not associated with higher resistance to P. falciparum. Our data have then been compared using chord distances (CD) with those from the literature on Africans (including Gambian Fulani) and Caucasoids. The Burkina Faso and Gambian Fulani turned out to be very different (CD=2.191). Moreover, Burkina Faso Fulani were very distant from sympatric Mossi and Rimaibé (CDs=1.912 and 1.884), whereas Gambian Fulani were similar to sympatric Mandinka and Wolof (CDs=0.412 and 0.388) to an extent comparable to that found between Mossi and Rimaibé (CD=0.555). Our study does not suggest the involvement of HLA I in the higher resistance to malaria of Fulani, and confirms a low, if any, Caucasoid component in their gene pool.
Distributions of HLA class I alleles and haplotypes in Bulgarians – contribution to understanding the origin of the population
Authors: Ivanova M. , Spassova P. , Michailova A. , Naumova E.
Published: March 2003

Abstract: In this study we present for the first time HLA class I allele and haplotype frequencies at DNA level in the Bulgarian population. HLA class I profile of Bulgarians has been compared to other European and Mediterranean populations of common historical background in order to clarify more precisely the origin of our population. Genetic distances, phylogenetic trees and correspondence analyses show that the Bulgarian population is more closely related to the Italian, the Mediterranean, the Armenian and the Romanian population than to the other East and West European population. This is further supported by the analysis of HLA class I haplotypes in Bulgarians. Most of them are also common in Europe. However their frequency pattern in Bulgarians is similar to the South European populations. The presence of some rare alleles and haplotypes indicated Asian genetic inflow. On the basis of HLA class I profile and supported by historical and anthropological data, we suggest that the Bulgarian population is characterized by the features of the Southern European anthropological type with some influence of other groups such as Asians, Turks, Armenians. Migrations and assimilation of many different ethnic groups are the major factor determining the genetic diversity of our population.