bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antibacterial activity of glass–ionomer cements, compomers and resin composites: relationship between acidity and material setting phase
Authors: VERMEERSCH G. , LELOUP G. , DELMÉE M. , VREVEN J. 
Published: April 2005

summary  Agar diffusion testing was used with four different media to evaluate the antibacterial activity of six products (one conventional glass–ionomer cement (GIC), two light‐activated glass–ionomers, two polyacid‐modified resin composites and one resin composite) on Streptoccoccus mutans. Their respective antibacterial activities were also compared during and after setting. The relationship between product acidity and antibacterial activity was evaluated.All the GICs demonstrated antibacterial properties in contrast to the polyacid‐modified resin composites and resin composite which did not shown any antibacterial effects. Vitrebond GIC exhibited higher antibacterial action, probably because of a cytotoxic photo‐initiator diphenyliodoniumchloride. A direct relationship between material acidity and growth inhibition of S. mutans was observed.
Family Altruism and Incentives
Authors: Gatti Roberta 
Published: April 2005

AbstractThis paper characterizes the pattern of intergenerational transfers that emerges in an altruistic model of the family when children's effort is explicitly made endogenous and parents have imperfect information on the stochastic income realizations of their children. It is shown that, if parents can credibly commit to a pattern of transfers, they will choose not to compensate children in bad outcomes as much as predicted by the standard (no uncertainty, no asymmetric information) dynastic model of the family. In this context, Ricardian equivalence holds whenever non‐negativity constraints are not binding.
International Environmental Agreements and Strategic Voting*
Authors: Buchholz Wolfgang , Haupt Alexander , Peters Wolfgang 
Published: April 2005

AbstractThis paper explores the outcome of an international environmental agreement when the governments are elected by their citizens. It also considers a voter's incentives for supporting candidates who are less green than she is. In the extreme case of “global” pollution, the elected politicians pay no attention to the environment, and the resulting international agreement is totally ineffective. Moreover, if governments cannot negotiate and have to decide non‐cooperatively (and voters are aware of this), the elected politicians can be greener, ecological damage can be lower and the median voter's payoff can be higher than in the case with bargaining.
Financial Markets and Economic Growth
Authors: Miller Merton H. 
Published: April 2005

The current economic problems in Southeast Asia can be attributed not to too much reliance on financial markets, but to too little. Like the U.S. economy a century ago, the emerging Asian economies do not have welldeveloped capital markets and so remain heavily dependent on their banking systems to finance growth.For all its benefits, banking is “not only basically 19th‐century technology, but disaster‐prone technology.” The extreme maturity (and, in some cases, currency) mismatch on banks' balance sheets plus the first‐come, first‐served nature of the deposit obligations mean that banks are inherently vulnerable to massive runs by depositors—and that their economies are subjected to periodic credit crunches. And, as the author says, “in the summer of 1997 a banking‐driven disaster struck in East Asia, just as it had struck so many times before in U.S. history.”In this century, In this century, the U.S. economy has steadily reduced its dependence on banks by developing “dispersed and decentralized” financial markets. In so doing, it has increased the efficiency of the U.S. capital allocation process and reduced its susceptibility to the credit crunches that have occurred throughout U.S. history. By contrast, Japan has not reduced its economy's dependence on banks, and its efforts to deal with its banking problems have served only to destabilize itself as well as its neighbors. Developing countries in Southeast Asia and elsewhere are urged not to follow the Japanese example, but to take measures aimed at developing financial markets and institutions that will either substitute for or complement bank products and services.
R&D AND CAPITAL MARKETS
Authors: Lev Baruch 
Published: April 2005

The substantial growth of R&D expenditures over the last two decades, together with the continuous substitution of knowledge (intangible) capital for physical (tangible) capital in corporate production functions, has elevated the importance of R&D in the performance of business enterprises. At the same time, however, the evaluation of corporate R&D activities by investors is seriously hampered by antiquated accounting rules and insufficient disclosure by corporations. Despite the fact that the expected benefits of R&D stretch over extended periods of time, corporate investments in R&D are immediately written off in financial reports, leaving no trace of R&D capital on balance sheets and causing material distortions of reported profitability.After a brief review of statistics documenting the growth and economic importance of corporate R&D in the U.S., the article presents a comparison of R&D disclosure regulations among industrialized nations that shows U.S. rules to be the least flexible in allowing management discretion in how they measure and report R&D. Next the author surveys the large and growing body of empirical research on R&D, which provides strong testimony to the substantial contribution of R&D to corporate productivity and shareholder value. Moreover, despite widespread allegations of stock market “short termism” throughout the 1980s and early '90s, the research indicates “unequivocally” that capital markets consider investments in R&D as a significant value‐increasing activity.But if investors clearly demonstrate a willingness to take the long view of R&D, there is also evidence of undervaluation of some R&D‐intensive companies—particularly those with low profitability—as well as other potential costs to corporations and investors stemming from inadequate public information about R&D. To help correct the reporting biases and distortions of R&D, the author offers some suggestions for investors and analysts that follow R&D‐intensive companies. In particular, he proposes (1) adjustment of reported data to reflect the capitalization and amortization of (instead of expensing) corporate R&D and (2) the use of various quantitative measures for gauging research capabilities and output, including citations of the firm's patents and measures indicating the share of current revenues coming from products developed within recent years.
WHEN DO STRATEGIC ALLIANCES CREATE SHAREHOLDER VALUE?
Authors: Chan Su Han , Kensinger John W. , Keown Arthur J. , Martin John D. 
Published: April 2005

This article reports the findings of the authors' study of the stock market reaction to 345 strategic alliances announced during the period 1983‐1992. The study reports statistically significant gains that, when translated into dollars, are divided roughly evenly between the larger and smaller partners (though the smaller partners experience larger percentage gains). Moreover, the value gains are largest in those cases in which two high‐tech firms ally to develop or apply new technology, while the market shows less enthusiasm for non‐technical or marketing alliances.The underlying rationale for strategic alliances is that each partner contributes its expertise to the relationship and gains access to some special resource or competence that it lacks—but without incurring the costs associated with creating a larger organization through a merger or joint venture. Consistent with this argument, the authors report that alliances are relatively long‐lasting, and are not preludes to merger or formal creation of joint venture entities.
CREATING VALUE IN PENSION PLANS (OR, GENTLEMEN PREFER BONDS)
Authors: Gold Jeremy , Hudson Nick 
Published: April 2005

Pension funds are typically one‐half to two‐thirds invested in equities because equities are expected to outperform other financial assets over the long term, and the long‐term nature of pension fund liabilities seems well suited to absorbing any short‐term return volatility. What's more, U.S. GAAP currently makes it possible to take credit in advance for the higher anticipated earnings on equity investments without acknowledging their inherent risk. But by allowing the higher expected returns from stocks to reduce a company's current pension expenses, the accounting treatment conflicts with some very basic principles of finance (in particular, the idea that investors must earn higher returns on riskier investments just to “break even”), conceals systematic biases in the actuarial analysis, and gives managers considerable latitude to manipulate the bottom line.The authors suggest a startlingly different approach. They argue that pension assets should be invested entirely in duration‐matched debt instruments for two reasons: (1) to capture the full tax benefits of pre‐funding their pension obligations and (2) to improve overall corporate risk profiles by converting general stock market risk into firm‐specific operating risk, where corporate managers should have a comparative advantage and can generate real value. Investing exclusively in bonds would take better advantage of the tax‐exempt status of pension plans and greatly reduce fund management costs, while at the same time helping o shore up fund quality and sharpening corporate executives' focus on their real operating assets.
VOLUNTARY DISCLOSURE PRACTICES: THE USE OF PRO FORMA REPORTING
Authors: Entwistle Gary , Feltham Glenn , Mbagwu Chima 
Published: April 2005

This article looks at how U.S. managers supplement GAAP earnings with pro forma reporting. Pro forma measures, which are not audited, are typically determined through an adjustment to GAAP‐based earnings. For example, a manager may choose to present an alternative to GAAP earnings that excludes period write‐offs and one‐time restructuring charges in order to present a more value‐relevant picture of the company's performance.The authors find that 77% of S&P 500 companies report pro forma results, and that pro forma measures are generally given greater prominence than GAAP earnings in corporate press releases. Based on the evidence, U.S. managers are using pro forma reporting strategically to affect investor perception of corporate performance. The SEC has recently issued rules to ensure that pro forma disclosure is not misleading. The authors present some guidelines on voluntary disclosure that might help forestall further regulation and preserve the ability to pursue this potentially informative practice.
CREATING VALUE WITH MERGERS AND ACQUISITIONS
Authors: Hazelkorn Todd , Zenner Marc , Shivdasani Anil 
Published: April 2005

This report addresses two key questions for today's top executives: Do acquisitions create value for acquirers? And under what circumstances have acquisitions created the most value for acquiring shareholders?The authors' analysis of over 1,500 completed deals by non‐financial companies in the United States over the past 12 years shows that, at announcement, acquirers' shareholders suffer small losses, on average, in the short term around the initial deal announcement. Over longer intervals, such as one or two years following the announcement of the transaction, acquirers tend to slightly outperform industry peers.The average or median market response hides tremendous variability in how the market has reacted to individual deals, however. This article provides evidence that the “right” M&A transaction can create substantial value for acquirers. One‐quarter of the transactions lead to market‐adjusted gains in excess of 5% for the acquirer and oneeighth of the transactions lead to gains in excess of 10% in the short term. However, some deals have also destroyed substantial shareholder value.Financing structure is a key driver of the stock market reaction. Stock‐financed transactions, on average, have a negative stock market reaction, while cash‐financed transactions have benefited acquirers in both the short term as well as the long term.Acquisitions of private companies or assets and units of public companies have consistently generated higher returns for acquirers than purchases of public companies.Moreover, EPS dilution is not a major driver of how the stock market reacts to a deal. Although “accretive” deals perform slightly better than “dilutive” ones in the short and long run, the difference is small and not statistically significant. Over the long run, acquiring shareholders have benefited the most from deals within the same industry and that avoid targets with relatively optimistic earnings growth projections.
Unique Long Terminal Repeat and Surface Glycoprotein Gene Sequences of Feline Leukemia Virus as Determinants of Disease Outcome
Authors: Chandhasin Chandtip , Coan Patricia N. , Pandrea Ivona , Grant Chris K. , Lobelle-Rich Patricia A. , Puetter Adriane , Levy Laura S. 
Published: April 2005

ABSTRACTThe outcome of feline leukemia virus (FeLV) infection in nature is variable, including malignant, proliferative, and degenerative disorders. The determinants of disease outcome are not well understood but are thought to include viral, host, and environmental factors. In particular, genetic variations in the FeLV long terminal repeat (LTR) and SU gene have been linked to disease outcome. FeLV-945 was previously identified as a natural isolate predominant in non-T-cell neoplastic and nonneoplastic diseases in a geographic cohort. The FeLV-945 LTR was shown to contain unique repeat elements, including a 21-bp triplication downstream of the enhancer. The FeLV-945 SU gene was shown to encode mutational changes in functional domains of the protein. The present study details the outcomes of infection with recombinant FeLVs in which the LTR and envelope (env) gene of FeLV-945, or the LTR only, was substituted for homologous sequences in a horizontally transmissible prototype isolate, FeLV-A/61E. The results showed that the FeLV-945 LTR determined the kinetics of disease. Substitution of the FeLV-945 LTR into FeLV-A/61E resulted in a significantly more rapid disease onset but did not alter the tumorigenic spectrum. In contrast, substitution of both the FeLV-945 LTR andenvgene changed the disease outcome entirely. Further, the impact of FeLV-945envon the disease outcome was dependent on the route of inoculation. Since the TM genes of FeLV-945 and FeLV-A/61E are nearly identical but the SU genes differ significantly, FeLV-945 SU is implicated in the outcome. These findings identify the FeLV-945 LTR and SU gene as determinants of disease.
Gamma Interferon-Dependent, Noncytolytic Clearance of Sindbis Virus Infection from Neurons In Vitro
Authors: Burdeinick-Kerr Rebeca , Griffin Diane E. 
Published: April 2005

ABSTRACTDue to the nonrenewable nature of neurons, recovery from viral infection of the central nervous system requires noncytopathic mechanisms for control of virus replication. Recovery from alphavirus encephalitis can occur without apparent neurological damage through the effects of antibody and gamma interferon (IFN-γ). To establish an in vitro cell culture system that will allow the study of mechanisms of IFN-γ-mediated control of Sindbis virus (SINV) replication in neurons, we have characterized the susceptibility to SINV infection and IFN-γ responsiveness of two neuronal cell lines that can be differentiated in vitro: CSM14.1, a rat nigral cell line, and NSC34, a mouse motor neuron cell line. Undifferentiated CSM14.1 and NSC34 cells were permissive for SINV and susceptible to virus-induced cell death. With differentiation, CSM14.1 cells reduced virus replication and became progressively resistant to virus-induced cell death, resulting in prolonged virus replication. NSC34 cells did not differentiate completely and became only partially resistant to SINV infection. Both CSM14.1 and NSC34 cells responded to pretreatment with IFN-γ by decreasing SINV replication. Differentiated CSM14.1 cells treated 24 h after infection with IFN-γ responded with increased cell viability and clearance of infectious virus. IFN-γ treatment sequentially altered the ratio of genomic to subgenomic viral RNA synthesis, promoted recovery of cellular protein synthesis, reduced viral protein synthesis, and inhibited viral RNA transcription within 24 h after treatment. We conclude that CSM14.1 cells provide an excellent model for the study of IFN-γ-mediated noncytolytic clearance of SINV from mature neurons.
Covert Human Immunodeficiency Virus Replication in Dendritic Cells and in DC-SIGN-Expressing Cells Promotes Long-Term Transmission to Lymphocytes
Authors: Nobile Cinzia , Petit Caroline , Moris Arnaud , Skrabal Katharina , Abastado Jean-Pierre , Mammano Fabrizio , Schwartz Olivier 
Published: April 2005

ABSTRACTHIV-1 virions are efficiently captured by monocyte-derived immature dendritic cells (iDCs), as well as by cell lines expressing the lectin DC-SIGN. Viral infectivity can be retained for several days, and even enhanced, before transmission to CD4+lymphocytes. The role of DC-SIGN in viral retention and enhancement of infection is not fully understood and varies according to the cell line expressing the lectin. We studied here the mechanisms underlying this process. We focused our study on X4-tropic human immunodeficiency virus (HIV) strains, since they were widely believed not to replicate in iDCs. However, we first show that X4 HIV replicates covertly and slowly in iDCs. This is also the case in Raji-DC-SIGN cells, which are classically used to study HIV transmission. We used either single-cycle or replicative HIV and measured viral RT and replication to further demonstrate that transfer of incoming virions from iDCs or DC-SIGN+cells occurs only on the short-term (i.e., a few hours after viral exposure). There is no long-term storage of original HIV particles in these cells. A few days after viral exposure, replicative viruses, and not single-cycle virions, are transmitted to CD4+cells. The cell-type-dependent activity of DC-SIGN reflects the ability of HIV to replicate covertly in some cells, and not in others.
Dengue Virus Inhibits Alpha Interferon Signaling by Reducing STAT2 Expression
Authors: Jones Meleri , Davidson Andrew , Hibbert Linda , Gruenwald Petra , Schlaak Joerg , Ball Simon , Foster Graham R. , Jacobs Michael 
Published: April 2005

ABSTRACT

Alpha/beta interferon (IFN-α/β) is a key mediator of innate antiviral responses but has little effect on the established replication of dengue viruses, which are mosquito-borne flaviviruses of immense global health importance. Understanding how the IFN system is inhibited in dengue virus-infected cells would provide critical insights into disease pathogenesis. In a recent study analyzing the ability of individual dengue virus-encoded proteins to antagonize the IFN response, nonstructural (NS) protein 4B and possibly NS2A and NS4A were identified as candidate IFN antagonists. In monkey cells, NS4B appeared to inhibit both the IFN-α/β and IFN-γ signal transduction pathways, which are distinct but overlapping (J. L. Munoz-Jordan, G. G. Sanchez-Burgos, M. Laurent-Rolle, and A. Garcia-Sastre, Proc. Natl. Acad. Sci. USA
100:
14333-14338, 2003). For this study, we examined the effects of dengue virus on the human IFN system, using cell lines that were stably transfected with self-replicating subgenomic dengue virus RNA (replicons) and that expressed all of the dengue virus nonstructural proteins together. We show here that in replicon-containing cells dengue virus RNA replication and the replication of encephalomyocarditis virus, an IFN-sensitive virus, are resistant to the antiviral effects of IFN-α. The presence of dengue virus replicons reduces global IFN-α-stimulated gene expression and specifically inhibits IFN-α but not IFN-γ signal transduction. In cells containing replicons or infected with dengue virus, we found reduced levels of signal transducer and activator of transcription 2 (STAT2), which is a key component of IFN-α but not IFN-γ signaling. Collectively, these data show that dengue virus is capable of subverting the human IFN response by down-regulating STAT2 expression.
Few Mutations in the 5′ Leader Region Mediate Fitness Recovery of Debilitated Human Immunodeficiency Type 1 Viruses
Authors: Yuste Eloísa , Bordería Antonio V. , Domingo Esteban , López-Galíndez Cecilio 
Published: April 2005

ABSTRACT

Repeated bottleneck passages of RNA viruses result in fitness losses due to the accumulation of deleterious mutations. In contrast, repeated transfers of large virus populations result in exponential fitness increases. Human immunodeficiency virus type 1 (HIV-1) manifested a drastic fitness loss after a limited number of plaque-to-plaque transfers in MT-4 cells. An analysis of the mutations associated with fitness loss in four debilitated clones revealed mutation frequencies in
gag
that were threefold higher than those in
env
. We now show an increase in the fitness of the debilitated HIV-1 clones by repeated passages of large populations. An analysis of the entire genomic nucleotide sequences of these populations showed that few mutations, from two to seven per clone, mediated fitness recovery. Eight of the 20 mutations affected coding regions, mainly by the introduction of nonsynonymous mutations (75%). However, most of the mutations accumulated during fitness recovery (12 of 20) were located in the 5′ untranslated leader region of the genome, and more specifically, in the primer binding site (PBS) loop. Two of the viruses incorporated the same mutation in the primer activation signal in the PBS loop, which is critical for the tRNA
3
Lys
-mediated initiation of reverse transcription. Moreover, 25% of the mutations observed were reversions. This fact, together with the presence of a large proportion of nonsynonymous replacements, may disclose the operation, during large population passages, of strong positive selection for optimal HIV-1 replication, which seems to be primarily affected by binding of the tRNA to the PBS and the initiation of reverse transcription.