bluuebunny/crossref_metadata_2025_split huggingface dataset:
Failure to confirm influence of Methyltetrahydrofolate reductase (MTHFR) polymorphisms on age at onset of Huntington disease
Authors: Hansen Wiebke , Saft Carsten , Andrich Jürgen , Müller Thomas , Wieczorek Stefan , Epplen Jörg T , Arning Larissa 
Published: December 2005

Abstract

Background
Huntington disease (HD) is a fully penetrant, autosomal dominantly inherited disorder associated with abnormal expansions of a stretch of perfect CAG repeats in the 5' part of the IT15 gene. The number of repeat units is highly predictive for the age at onset (AO) of the disorder. But AO is only modestly correlated with repeat length when intermediate HD expansions are considered. Recently, suggestive association has been reported between a single nucleotide polymorphism (SNP; rs1801131, also known as A1298C) in the methyltetrahydrofolate reductase (MTHFR) gene and AO of HD. 5,10-MTHFR is a key enzyme in the folate metabolism, diverting metabolites toward methylation reactions or nucleotide synthesis. Using part of a previously established study cohort plus additional patients and appropriate statistical methods, we reinvestigated two polymorphisms in the MTHFR gene, C677T and A1298C, as well as their association with AO in 167 HD patients.

Results
There was no statistically significant impact on AO for HD patients, neither of MTHFR SNPs nor of the combinations thereof.

Conclusion
Contrary to previously described evidence the A1298C polymorphism in the MTHFR gene does not appear to modulate AO of HD patients.
Chronic Fatigue Syndrome – A clinically empirical approach to its definition and study
Authors: Reeves William C , Wagner Dieter , Nisenbaum Rosane , Jones James F , Gurbaxani Brian , Solomon Laura , Papanicolaou Dimitris A , Unger Elizabeth R , Vernon Suzanne D , Heim Christine 
Published: December 2005

Abstract

Background
The lack of standardized criteria for defining chronic fatigue syndrome (CFS) has constrained research. The objective of this study was to apply the 1994 CFS criteria by standardized reproducible criteria.

Methods
This population-based case control study enrolled 227 adults identified from the population of Wichita with: (1) CFS (n = 58); (2) non-fatigued controls matched to CFS on sex, race, age and body mass index (n = 55); (3) persons with medically unexplained fatigue not CFS, which we term ISF (n = 59); (4) CFS accompanied by melancholic depression (n = 27); and (5) ISF plus melancholic depression (n = 28). Participants were admitted to a hospital for two days and underwent medical history and physical examination, the Diagnostic Interview Schedule, and laboratory testing to identify medical and psychiatric conditions exclusionary for CFS. Illness classification at the time of the clinical study utilized two algorithms: (1) the same criteria as in the surveillance study; (2) a standardized clinically empirical algorithm based on quantitative assessment of the major domains of CFS (impairment, fatigue, and accompanying symptoms).

Results
One hundred and sixty-four participants had no exclusionary conditions at the time of this study. Clinically empirical classification identified 43 subjects as CFS, 57 as ISF, and 64 as not ill. There was minimal association between the empirical classification and classification by the surveillance criteria. Subjects empirically classified as CFS had significantly worse impairment (evaluated by the SF-36), more severe fatigue (documented by the multidimensional fatigue inventory), more frequent and severe accompanying symptoms than those with ISF, who in turn had significantly worse scores than the not ill; this was not true for classification by the surveillance algorithm.

Conclusion
The empirical definition includes all aspects of CFS specified in the 1994 case definition and identifies persons with CFS in a precise manner that can be readily reproduced by both investigators and clinicians.
A balanced transcription between telomerase and the telomeric DNA-binding proteins TRF1, TRF2 and Pot1 in resting, activated, HTLV-1-transformed and Tax-expressing human T lymphocytes
Authors: Escoffier Emmanuelle , Rezza Amélie , Roborel de Climens Aude , Belleville Aurélie , Gazzolo Louis , Gilson Eric , Duc Dodon Madeleine 
Published: December 2005

Abstract

Background
The functional state of human telomeres is controlled by telomerase and by a protein complex named shelterin, including the telomeric DNA-binding proteins TRF1, TRF2 and Pot1 involved in telomere capping functions. The expression of hTERT, encoding the catalytic subunit of telomerase, plays a crucial role in the control of lymphocyte proliferation by maintaining telomere homeostasis. It has been previously found that hTERT activity is down-regulated by the human T cell leukaemia virus type 1 (HTLV-1) Tax protein in HTLV-1 transformed T lymphocytes. In this study, we have examined the effects of Tax expression on the transcriptional profile of telomerase and of shelterin in human T lymphocytes.

Results
We first provide evidence that the up-regulation of hTERT transcription in activated CD4+ T lymphocytes is associated with a down-regulation of that of TERF1, TERF2 and POT1 genes. Next, the down-regulation of hTERT transcription by Tax in HTLV-1 transformed or in Tax-expressing T lymphocytes is found to correlate with a significant increase of TRF2 and/or Pot1 mRNAs. Finally, ectopic expression of hTERT in one HTLV-1 T cell line induces a marked decrease in the transcription of the POT1 gene. Collectively, these observations predict that the increased transcriptional expression of shelterin genes is minimizing the impact on telomere instability induced by the down-regulation of hTERT by Tax.

Conclusion
These findings support the notion that Tax, telomerase and shelterin play a critical role in the proliferation of HTLV-1 transformed T lymphocytes.
Three-Year Analysis of Tapered Screw-Vent Implants Placed into Extraction Sockets Grafted With Mineralized Bone Allograft
Authors: Minichetti John C. , D'Amore Joseph C. , Hong Anna Y. J. 
Published: December 2005

Abstract
With clinicians placing more dental implants, it is becoming increasingly important to maintain bone volume after tooth extraction. This article reports the results of implants placed into extraction sites grafted with particulate mineralized bone allograft (Puros). A total of 313 extraction sites were grafted with mineralized bone graft during a 36-month period. A total of 252 Tapered Screw-Vent dental implants were placed into the grafted extraction sites after a 4- to 7-month healing period. All reentries revealed a bony hard structure acceptable for osteotomy preparation. A total of 244 of these implants have been restored with fixed prosthesis and 6 with removable overdentures for a total of 250 loaded implants. A total of 6 implants failed, which required their removal (2 implants before load and 4 after loading), resulting in a 97.6% implant success rate. We conclude that mineralized human allograft placed into extraction sites is clinically useful to maintain bone volume. This material provided a bony hard structure acceptable for implant placement with good success rates.
House Mental Classification System of Denture Patients: The Contribution of Milus M. House
Authors: Winkler Sheldon 
Published: December 2005

Abstract
Although Dr Milus M. House is credited with devising a method to describe the mental classification of complete denture patients, a review of the literature raises questions regarding the origin of the system. Dr Ewell Neil should have received credit for developing the classification system attributed to Dr House. The contribution of Dr House appears to be a detailed expansion of the classification and the subsequent popularization of the system.
Incentives and Coordination in Hierarchies
Authors: Mookherjee Dilip , Reichelstein Stefan 
Published: December 2005

Abstract
The internal organization of large firms as well as procurement and regulation contexts frequently involve a hierarchical nexus of contracts, with substantial delegation of decision making across layers. Such hierarchical delegation of decision making creates problems of aligning incentives of vertically related agents, and coordinating the actions of different branches of the hierarchy. In a principal-agent setting with private information, it is shown that under certain assumptions (top-down contracting, observability of subcontracting outcomes, absence of limited liability constraints) the hierarchy can implement second-best allocations. Incentive problems are overcome via compensations that are linear in a measure of performance of the concerned department, defined as the difference between a measure of imputed revenues and procurement costs. The coordination problem is overcome by conditioning output targets and payments on cost reports submitted by other branches; despite this, agents' strategies are dominant with respect to the behavior of members of other branches. The result provides conditions for the lack of a `control loss' from hierarchical decentralization of decision making, owing to incentive or coordination problems.
Equilibrium Departures from Common Knowledge in Games with Non-Additive Expected Utility
Authors: Mukerji Sujoy , Shin Hyun Song 
Published: December 2005

Abstract
This paper concerns the interpretation of equilibrium in non-additive beliefs in two-player normal form games. We argue that such equilibria involve beliefs and actions which are consistent with a lack of common knowledge of the game. Our argument rests on representation results which show that different notions of equilibrium in games with non-additive beliefs may be reinterpreted as equilibrium in associated games of incomplete information with additive (Bayesian) beliefs where common knowledge of the (original) game does not apply. The representation results show one way of comparing and understanding the various notions of equilibrium, for games with non-additive beliefs, advanced in the literature.
Bilateral Trade and Opportunism in a Matching Market
Authors: Ramey Garey , Watson Joel 
Published: December 2005

Abstract
We develop a model of bilateral contracting in a dynamic market setting. Asset owners must be paired via a matching process in order to form productive relationships involving long-term investments and ongoing effort. Market frictions shape the owners' incentives to invest in the absence of complete contracts. We identify cases in which there exists an optimal positive level of market friction implementing first-best investment levels. We also endogenize the choice between integrated and nonintegrated organizational forms. Changes in structural variables can induce crashes by disrupting existing relationships.
Bargaining over Risky Assets
Authors: Yildiz Muhamet 
Published: December 2005

Abstract
We analyze the subgame-perfect equilibria of a game where two agents bargain in order to share the risk in their assets that will pay dividends once at some fixed date. The uncertainty about the size of the dividends is resolved gradually by the payment date and each agent has his own view about how the uncertainty will be resolved. As agents become less uncertain about the dividends, some contracts become unacceptable to some party to such an extent that at the payment date no trade is possible. The set of contracts is assumed to be rich enough to generate all the Pareto-optimal allocations. We show that there exists a unique equilibrium allocation, and it is Pareto-optimal. Immediate agreement is always an equilibrium outcome; under certain conditions, we further show that in equilibrium there cannot be a delay. In this model, the equilibrium shares depend on how the uncertainty is resolved, and an agent can lose when his opponent becomes more risk-averse. Finally, we characterize the conditions under which every Pareto-optimal and individually rational allocation is obtainable via some bargaining procedure as the unique equilibrium outcome.
The Noisy Duopolist
Authors: Spector David 
Published: December 2005

Abstract
This paper provides an explanation for noisy pricing based on the strategic interaction of two firms competing in prices. When a firm adds noise to its prices, undercutting it becomes harder. Therefore, noisy pricing allows a firm to either exclude a competitor while charging supracompetitive prices, or to soften competition and have both firms earn supracompetitive profits. Such behavior leads to prices lying between competitive and monopolistic levels, and harms consumers and social welfare. It occurs in equilibrium if firms set prices sequentially, and in some equilibria of a repeated game of simultaneous price-setting if one firm is patient.
Regulation by Negotiation: the Private Benefit Bias
Authors: Lambert-Mogiliansky Ariane , Picard Pierre 
Published: December 2005

Abstract
This paper analyses the role of the managers' non-pecuniary private benefits in an incomplete contract approach to the regulation of utilities. Private benefits may take various forms: excessive job security, perks, overstaffing, feeling of power. The model describes the relationship between a government and the manager of a firm which produces a pure public good, under private or public ownership. The firm's production is characterized by its quantity and its flexibility, the latter corresponding to adaptability to changes in consumers' tastes or to new technologies. A larger output quantity entails larger private benefits to the manager, while increasing flexibility runs counter to the managers' private benefits. The manager decides upon non-verifiable investment in human and non-human capital so as to facilitate an increase in the output quantity (capacity investment) or to improve the firm's flexibility (investment in organizational adaptability). We compare the effects of the ownership regime on the manager's incentives to invest and on the aggregate welfare. The private firm under-invests in capacity and organizational flexibility. This is because the government holds up a part of the gains through ex post renegotiation of the initial (incomplete) contract. Our analysis also highlights a fundamental bias in the investment behavior of the state-owned firm: the manager of the public firm only invests in capacity (he may even invest more than under private ownership) but he never invests in organizational adaptability. The model shows that an increase in the government's bargaining power exacerbates the hold up problem when the firm is privately owned, but that this result may be reversed for capacity investment under public ownership. Finally, we show that the superiority of private or public ownership depends simultaneously on three factors: the respective bargaining power of the manager and of the government, the degree of specificity of investments and the relative weight of quantity and flexibility concerns in the social welfare.
A Simple Linear Programming Approach to Gain, Loss and Asset Pricing
Authors: Rodríguez Longarela Iñaki 
Published: December 2005

Abstract
Bernardo and Ledoit (2000) develop a very appealing framework to compute pricing bounds based on what they call gain-loss ratio. Their method has many advantages and very interesting properties and so far one important drawback: the complexity of the numerical computation of the pricing bounds. In this note we provide a simple procedure for their computation which only entails solving a linear optimization program.
U.S. Regional Income and Technology: A Unit-Root and Cointegration Study
Authors: Alvi Eskander , Rahman Habibur 
Published: December 2005

Abstract
This paper examines income convergence across U.S. regions for the period 1929-2002 using unit root and cointegration techniques. The findings suggest it is difficult to reject non-convergence in per capita incomes across regions even when endogenous breakpoints are included. Interestingly, we also find evidence of cointegration among technology and incomes in the leading regions, but not in the lagging ones, identifying technology as a factor that contributes to the lack of convergence.
Creative Destruction and Policy in a Model of Endogenous Growth
Authors: Mateos-Planas Xavier 
Published: December 2005

Abstract
This paper extends a model of endogenous growth through the introduction of a component of knowledge that makes new technologies more productive than older vintages. Creative destruction or obsolescence of technologies underlies the growth process. In this setup, the growth effects of various policies are analyzed. These policies include selective subsidies to firms that produce final output, a general lump-sum tax on final-output firms, and openness to trade with a less developed country. The results show the existence of growth effects that have not been studied in the previous literature.
Ramsey-Friedman Optimality with Banking Time
Authors: Gillman Max K , Yerokhin Oleg 
Published: December 2005

Abstract
This paper conducts a Ramsey analysis within an endogenous growth cash-in-advance economy with policy commitment. Credit and money are alternative payment mechanisms that act as inputs into the household production of exchange. The credit is produced with a diminishing returns technology with Inada conditions that implies along the balanced-growth path a degree one homogeneity of effective banking time. This tightens the restrictions found within shopping time economies while providing a production basis for the Ramsey-Friedman optimum that suggests a special case of Diamond and Mirrlees (1971).
Firm Entry with an Imperfect Labor Market
Authors: Johnson Justin P. 
Published: December 2005

Abstract
An economy is considered in which new firms require time to learn whether they will grow in size and profitability in the long run. The labor market is imperfectly competitive. I show that inefficient levels of firm entry will generally exist. Whether under or over entry occurs is tightly related to the bargaining power of labor, but the logic behind my result differs dramatically from other work which has identified a similar link. The theory may shed some light on the continuing debate over the contribution of small firms to economic growth, and suggests that, in some cases, subsidizing small firms may be socially beneficial.
Monetary Policy and the Information Content of the Yield Spread
Authors: Feroli Michael 
Published: December 2005

Abstract
This paper investigates the determinants of the ability of the yield spread to predict output fluctuations conditional on the short rate. In the model of the paper, this predictive power is contingent on the monetary authority's reaction function. In particular, expectations of monetary policy actions are crucial for the spread to predict output. Furthermore, numerical experiments suggest that the post-1979 decrease in the yield spread's predictive power is due to a shift in the monetary policy reaction function at that time.
Output Composition of the Monetary Policy Transmission Mechanism in Japan
Authors: Fujiwara Ippei 
Published: December 2005

Abstract
In this paper, we investigate the output composition of the monetary policy transmission mechanism in Japan. The predominant channel through which monetary policy affects output in Japan is usually thought to be the investment channel, namely the process whereby a change in the interest rate alters the cost of capital and therefore investment. In the United States, however, the consumption channel, which works through intertemporal substitution, is commonly considered the more significant of the two. The aim of this paper is twofold: 1) based on analysis using VAR models to understand which of the two channels, the consumption channel or the investment channel, plays the more important role in the transmission of the Japanese monetary policy; and 2) to contribute to the research on what Angeloni, Kashyap, Mojon and Terlizzese (2003) term the "Output Composition Puzzle," referring to the fact that whereas in the United States the predominant driver of output changes is the consumption channel, in the Euro area it is the investment channel. Results obtained from the Japanese models imply that the investment channel is more important.
Exchange Rate Regimes and Financial Dollarization: Does Flexibility Reduce Currency Mismatches in Bank Intermediation?
Authors: Arteta Carlos O. 
Published: December 2005

Abstract
The dollarization of bank deposits and credit is widespread in developing countries, resulting in varying degrees of currency mismatches in domestic financial intermediation. It is argued that flexible exchange rate regimes generally encourage banks to match dollar-denominated liabilities with a corresponding amount of dollar-denominated assets. Does this argument apply to the behavior of dollar deposits and credits in financially dollarized economies? A new database on deposit and credit dollarization in developing and transition countries is assembled and used to address this question. Empirical results suggest that, if anything, floating regimes are positively associated with deposit dollarization more strongly than they are associated with credit dollarization. As a consequence, currency mismatches in domestic financial intermediation seem to be greater under floating regimes.
An Active Public Investment Rule and the Downsizing Experience in the US: 1960-2000
Authors: Marrero Gustavo A. 
Published: December 2005

Abstract
We use a simple growth model with public capital to examine the evolution of the US macroeconomy and to discuss the implications of the public infrastructure decline for the productivity slowdown over the last four decades. The main difference of the model to other papers in the related literature is that public investment is actively managed as a non-linear function of the state of the economy, and is not a constant fraction of output in every period. The active management policy delivers transition dynamics that reproduce the public capital downsizing episode, but that accounts for only a minor fraction of the observed productivity slowdown. However, taking into consideration higher rates of returns to public capital or the reallocation of public resources from productive to unproductive expenditures, which is consistent with the US experience in the 70s and 80s, the model simulation accounts for most of the observed productivity slowdown.
Policy Effects in the Post Boom U.S. Economy
Authors: Fair Ray C 
Published: December 2005

Abstract
The paper analyzes the question why the U.S. economy in the 2000:4--2004:3 period was sluggish in light of the large expansionary fiscal and monetary policies that took place. The answer does not appear to be that there were large structural changes in the economy or systematic bad shocks. This paper tests for such changes and shocks, and the results are generally negative. Instead, the main culprits seem to be large negative effects from declines in the stock market and exports. Although not tested in this paper, some of the decline in exports may be the result of the stock market decline, in which case most of the explanation is simply the stock market decline itself.
Human Capital and Growth: An Alternative Accounting
Authors: Rangazas Peter C 
Published: December 2005

Abstract
This paper re-examines the importance of human capital in explaining economic growth. Previous studies are extended by including schooling investments of both time and goods within the school year, a human capital externality, and imperfect substitution between white collar and manual tasks. The model of worker productivity used to conduct the growth accounting is consistent with (1) rates of return to time and goods investment in education, (2) white collar wage premia, and (3) trendless worker productivity growth rates in the United States over the 20th century. The analysis suggests that about one third of United States growth over this period was related to human capital accumulation, accounting for an average annual growth rate of 0.6 to 0.7 percent. The model also implies that neoclassical inputs can account for 5.5 to 8.5-fold differences in worker productivity across rich and poor countries.