bluuebunny/crossref_metadata_2025_split huggingface dataset:
Removal of neutralized model parvoviruses and enteroviruses in human IgG solutions by nanofiltration
Authors: Omar A. , Kempf C. 
Published: March 2003

BACKGROUND : Nanofiltration has proven to be an effective technology for virus removal. The small nonenveloped viruses, such as HAV and parvovirus B19 (B19), are evidently more difficult to remove than the larger enveloped viruses. However, since antibodies against these viruses, HAV and B19, are constantly present in large plasma pools, it is conceivable that antibody binding will lead to an increase in size of the viruses due to a corona of antibodies on the virus surfaces. These enlarged viruses should be easier to remove by nanofiltration than naked viruses. In this study, antibody‐coated viruses and free virions were subjected to nanofiltration to determine whether the antibody‐ mediated increase in size contributes to the elimination of viruses which are otherwise too small to be retained by filters of a given nominal pore diameter. STUDY DESIGN AND METHODS : One‐percent IgG or 1‐percent albumin solutions were spiked with bovine enterovirus (BEV) and filtered through 50‐nm filters. This virus cross‐reacts with antibodies in pooled human IgG solutions but persists as free virions in albumin solutions. Similarly, two parvoviruses, bovine parvovirus (BPV) and minute virus of mice (MVM), in 1‐percent IgG solutions were filtered through 20‐nm filters. BPV cross‐reacts with antibodies in human IgG, whereas MVM remains unaffected. Virus removal was assessed by in vitro infectivity assays. Two methods were developed to displace the antibodies from BEV and BPV and thereby render them accessible for titration. RESULTS : Antibody‐coated BEV was eliminated to below detection limit by the 50‐nm filters (logarithmic reduction factors [LRF]≥ 5), while free BEV virions passed without restraint through the same filters. Similarly, antibody‐coated BPV was completely retained by the 20‐nm filters (LRF ≥ 5). MVM virions were strongly retained by the 20‐nm filters; however, the virus was still detectable in the filtrate. CONCLUSION : These results indicate that viruses with bound antibodies are efficiently eliminated by nanofiltration by use of filters having nominal pore sizes larger than the diameter of the respective free virions.
Inhibition of murine GVHD by PEN110 treatment
Authors: Fast Loren D. , DiLeone Gilbert , Edson Clark M. , Purmal Andrei 
Published: March 2003

BACKGROUND: The presence of WBCs in blood components is the primary factor influencing the immunologic consequences of transfusion, such as GVHD and alloimmunization. Depletion or inactivation of WBCs can reduce the deleterious responses. Because treatment with PEN110 (Inactine, V. I. Technologies), an ethyleneimine derivative that disrupts nucleic acid replica‐ tion, was shown to inactivate in vitro human PBMNC function, the ability of PEN110‐treated cells to trigger GVHD or alloantibodies was studied with in vivo murine models.STUDY DESIGN AND METHODS: In vitro assays were employed to confirm that PEN110 treatment inactivated murine splenocyte function as effectively as for human PBMNCs. In vivo experiments in mice examined the ability of PEN110‐treated cells to induce GVHD responses in a parent into F1hybrid GVHD model, to induce alloantibodies, to stimulate MHC‐restricted cytolytic T lymphocyte responses, and to persist after injection.RESULTS: PEN110‐treated murine splenocytes did not respond or induce responses in any in vitro or in vivo assay. The PEN110‐treated cells were eliminated from blood and secondary lymphoid organs much more rapidly than were untreated cells.CONCLUSION: PEN110 treatment prevents the development of GVHD and alloantibody production following WBC transfusion in a murine model system, supporting the continued development of PEN110 treatment of cellular blood components as an alternative to gamma irradiation for the prevention of GVHD.
Inactivation of HIV in blood
Authors: Ohagen Asa , Gibaja Veronica , Aytay Saika , Horrigan Jeff , Lunderville Douglas , Lazo Aris 
Published: March 2003

BACKGROUND: The residual risk of HIV infection after HIV screening tests in combination with the risk of new emerging pathogens entering the blood supply has sparked research on the development of a technology for reduction of pathogens in RBCs.STUDY DESIGN AND METHODS: HIV‐1 was treated with PEN110 (INACTINE) and analyzed for the kinetics of virus reduction in RBC, the effect of PEN110 on nucleic acids, the integrity of the virus morphology and viral proteins, and the ability of the virus to bind HIV cell receptors and enter susceptible cells.RESULTS: PEN110 effectively reduced HIV‐1 to the limit of detection for a reduction factor of at least 5.57 log 50 percent tissue culture infectious dose per bulk test. The PEN110‐treated virions maintained their morphology, protein integrity, and functionality. However, the PEN110‐treated HIV‐1 RNA genome was neither functional to serve as a template for RT‐PCR amplification of about 1 kb nor able to support viral DNA synthesis in cell culture.CONCLUSION: These results suggest that PEN110 inactivates HIV‐1 by targeting the viral nucleic acid.
Reliability of bedside ABO testing before transfusion
Authors: Migeot Virginie , Ingrand Isabelle , Salmi Louis Rachid , Ingrand Pierre 
Published: March 2003

BACKGROUND: Previous studies of bedside transfusion compatibility tests have shown high rates of erroneous transfusion decision, due to defective techniques and poor user performance. An experimental study was conducted to evaluate the error rate obtained with a new ready‐to‐use device (Vu‐Test, Medigis), in comparison with the most popular bedside card used in France (Safety‐Test ABO, Diagast Laboratories).STUDY DESIGN AND METHODS: A stratified random sample of nurses performed, in the clinical departments where they worked, cross‐matches on 12 randomly and blindly selected paired donor‐recipient blood samples with Safety‐Test ABO and Vu‐Test. The nurses detected agglutination, interpreted compatibility, decided whether to transfuse, and gave their opinion of the two devices. Three independent experts reviewed photographs of each test result.RESULTS: Thirty‐five trained nurses and 10 student nurses carried out 268 tests with each device. One‐ hundred ninety tests (70.9%) performed with Safety‐Test ABO and 177 tests (66.0%) performed with Vu‐Test were entirely error‐free (p = 0.23). The risk of erroneous detection of agglutination was not different between the devices (p = 0.69), but was significantly lower when the nurse had experience in transfusion (p < 0.001). According to the experts, Vu‐Test was significantly better than Safety‐Test ABO.CONCLUSION: Although the experts considered Vu‐Test to be better than Safety‐Test ABO, error rates were high with both devices.
Transfusion‐transmitted HBV infection in an endemic area: the necessity of more sensitive screening for HBV carriers
Authors: Wang Jin‐Town , Lee Cha‐Ze , Chen Pei‐Jer , Wang Teh‐Hong , Chen Ding‐Shinn 
Published: March 2003

BACKGROUND: By NAT, HBV DNA is occasionally detectable in blood donors with past HBV infection but negative for HBsAg. Whether or not these donors can cause transfusion‐transmitted HBV infections is uncertain.STUDY DESIGN AND METHODS: To determine whether or not donors with past HBV infection but negative for HbsAg can cause HBV transfusion‐transmitted infections, recipients followed for blood transfusion in a university medical center in Taiwan were studied. HBV DNA and serologic markers were tested in donors and recipients.RESULTS: Of 1038 enrolled recipients, 910 completed the 6‐month post‐transfusion follow‐up visit. Of these, only 39 patients (4.3%) tested negative on the pretransfusion sample for HBsAg, anti‐HBs, anti‐HBc, and HBV DNA by PCR. These 39 HBV‐naive recipients had been transfused with blood from 147 donations for which stored samples were available for HBV DNA testing by PCR; 11 of these HBsAg‐negative samples tested positive for HBV DNA and anti‐HBc. Two of the 11 patients who received the HBV‐DNA‐positive donations (18%) became positive for HBV DNA, and one seroconverted to anti‐HBc and finally to anti‐HBs, with a mild transient elevation of serum ALT activities. Based on the one confirmed case of HBV transmission, a projection was made that approximately 200 post‐transfusion HBV infections could occur in one million units of transfused blood in Taiwan.CONCLUSIONS: In HBV‐endemic areas like Taiwan, where blood donors are screened for HBsAg only, the risk of transfusion‐transmitted HBV appears to be substantial. Implementation of NAT for blood screening in these settings warrants consideration.
The Corporate Cost of Capital and the Return on Corporate Investment
Authors: Fama Eugene F. , French Kenneth R. 
Published: March 2003

ABSTRACTWe estimate the internal rates of return earned by nonfinancial firms on (i) the initial market values of their securities and (ii) the cost of their investments. The return on value is an estimate of the overall corporate cost of capital. The estimate of the real cost of capital for 1950–96 is 5.95 percent. The real return on cost is larger, 7.38 percent, so on average corporate investment seems to be profitable. A by‐product of calculating these returns is information about the history of corporate earnings, investment, and financing decisions that is perhaps more interesting than the returns.
The Impact of Trader Type on the Futures Volatility‐Volume Relation
Authors: Daigler Robert T. , Wiley Marilyn K. 
Published: March 2003

ABSTRACTWe examine the volatility‐volume relation in futures markets using volume data categorized by type of trader. We find that the positive volatility‐volume relation is driven by the general public, a group of traders who are distant from the trading floor and therefore without precise information on order flow. Clearing members and floor traders who observe order flow often decrease volatility. Our findings are consistent with Shalen's (1993) hypothesis that uninformed traders who cannot differentiate liquidity demand from fundamental value change increase volatility.
Capital Gains Tax Rules, Tax‐loss Trading, and Turn‐of‐the‐year Returns
Authors: Poterba James M. , Weisbenner Scott J. 
Published: March 2003

ABSTRACTChanges in the capital gains tax rules facing individual investors do not affect the incentives for “window dressing” by institutional investors, but they can affect the incentives for year‐end tax–induced trading by individual investors. Empirical evidence for the 1963 to 1996 period suggests that when the tax law encouraged taxable investors who accrued losses early in the year to realize their losses before year‐end, the correlation between early year losses and turn‐of‐the‐year returns was weaker than when the law did not provide such an early realization incentive. These findings suggest that tax‐loss trading contributes to turn‐of‐the‐year return patterns.
Contagious Speculation and a Cure for Cancer: A Nonevent that Made Stock Prices Soar
Authors: Huberman Gur , Regev Tomer 
Published: March 2003

ABSTRACTA Sunday New York Times article on a potential development of new cancer‐curing drugs caused EntreMed's stock price to rise from 12.063 at the Friday close, to open at 85 and close near 52 on Monday. It closed above 30 in the three following weeks. The enthusiasm spilled over to other biotechnology stocks. The potential breakthrough in cancer research already had been reported, however, in the journal Nature, and in various popular newspapers (including the Times) more than five months earlier. Thus, enthusiastic public attention induced a permanent rise in share prices, even though no genuinely new information had been presented.
Do Credit Spreads Reflect Stationary Leverage Ratios?
Authors: Collin‐Dufresne Pierre , Goldstein Robert S. 
Published: March 2003

ABSTRACTMost structural models of default preclude the firm from altering its capital structure. In practice, firms adjust outstanding debt levels in response to changes in firm value, thus generating mean‐reverting leverage ratios. We propose a structural model of default with stochastic interest rates that captures this mean reversion. Our model generates credit spreads that are larger for low‐leverage firms, and less sensitive to changes in firm value, both of which are more consistent with empirical findings than predictions of extant models. Further, the term structure of credit spreads can be upward sloping for speculative‐grade debt, consistent with recent empirical findings.
Who Blinks in Volatile Markets, Individuals or Institutions?
Authors: Dennis Patrick J. , Strickland Deon 
Published: March 2003

ABSTRACTWe investigate the relationship between the ownership structure and returns of firms on days when the absolute value of the market's return is two percent or more. We find that a firm's abnormal return on these days is related to the percentage of institutional ownership, that there is abnormally high turnover in the firm's shares on these days, and that this abnormal turnover is significantly related to the percentage of institutional ownership in the firm. Taken together, these results are consistent with positive feedback herding behavior on the part of some institutions, particularly mutual and pension funds.
Option Volume and Stock Prices: Evidence on Where Informed Traders Trade
Authors: Easley David , O'Hara Maureen , Srinivas P.S. 
Published: March 2003

ABSTRACTThis paper investigates the informational role of transactions volume in options markets. We develop an asymmetric information model in which informed traders may trade in option or equity markets. We show conditions under which informed traders trade options, and we investigate the implications of this for the linkage between markets. Our model predicts an important informational role for the volume of particular types of option trades. We empirically test our model's hypotheses with intraday option data. Our main empirical result is that negative and positive option volumes contain information about future stock prices.
From Rubble to Virtual Reality: Photogrammetry and the Virtual World of Ancient Ayutthaya, Thailand
Authors: Ogleby C. L. 
Published: March 2003

For in excess of 100 years, photogrammetry has played a significant role in documenting the cultural heritage of nations and peoples. Many recent advances in the technique have enhanced the use of photogrammetry as a recording tool, enabling more complex representations of objects and moving access to the procedure from the expert to the interested user. Some of these recent developments include low cost digital photogrammetric systems, image sequence analysis, bundle adjustment and camera calibration procedures, and three dimensional laser scanning. An overview of some of these developments is given in this paper.The University of Melbourne, in conjunction with Chulalongkorn University in Bangkok, has been working on a project to create a computer visualization of the ancient Thai city of Ayutthaya. This project has blended three dimensional CAD models of the architectural features of Ayutthaya with historical research and artistic rendering to build a realistic representation of this city as it may have existed in the past.The model of the city has been built up from historical “maps”, aerial photographs, field survey and the use of photogrammetry to derive models of individual wat, chedi, prang (see GLOSSARY) and statuary. The historical research conducted in Thailand has provided the basis for the determination of the most likely location and appearance of the missing structures. The CAD models created from the photogrammetry have been visualized by the addition of surface textures and materials and rendered in as realistic a manner as possible. The virtual city has also been augmented by the incorporation of live actors in the computer reconstruction.When completed, the end product will be capable of producing an experience of daily life in Ayutthaya, with the potential for giving the user a level of interaction. The reconstruction will also be used as the basis of a variety of educational products to be produced in Thailand on a number of different media, including a bilingual CD‐ROM already developed to “proof‐of‐concept” stage.
Disconnect in the Hollow State: The Pivotal Role of Organizational Capacity in Community‐Based Development Organizations
Authors: Fredericksen Patricia , London Rosanne 
Published: March 2003

Partnerships between government and community‐based development organizations (CBDOs) have proven to be central to long‐term neighborhood revitalization in many settings. These successes, coupled with the political popularity of community‐driven projects, have stimulated further reliance on this approach. Unfortunately, scant research has been done on the organizational capacity of local community‐based development organizations to administer these projects. It may be that many of them do not have the capacity to do the job.This article examines elements of organizational capacity in CBDOs developing affordable housing in a United States‐Mexico border community. Evidence of capacity was limited, raising serious questions about the implementation of public policy in the hollow state. In their haste to contract with not‐for‐profits to create affordable housing, government officials may not be considering the serious possibility that CBDOs do not have the capacity to deliver services or effectively administer projects over time.
Outsourcing Public Health Laboratory Services: A Blueprint for Determining Whether to Privatize and How
Authors: Avery George 
Published: March 2003

In a continuing effort to reform and reinvent the way public organizations do business, the outsourcing of services has become a popular tool, particularly as resource constraints limit options available to governments. All too often, the decision is made, for reasons of ideology or resource constraints, to outsource services without giving careful consideration to the impact of privatization on the core missions of an agency, or whether privatization, in fact, offers real cost savings. Purchasing tools designed for traditional commodity purchases are often grossly unsuited for making decisions on specialized technical services.This article suggests a process for the evaluation of an option to outsource laboratory services. It suggests that, prior to contracting or privatizing services, the concerned agency should evaluate:the impact on the agency's core missionthe availability, stability, and reliability of private sector service providersthe relative costs of internal and external (public or private sector) service providersthe potential impact on regulatory enforcementthe ability to monitor the performance of external providerspotential conflicts of interestBased on this model, the ongoing internal evaluation of services offers public agencies management tools to obtain the best value for the taxpayer dollar, not only in terms of the raw cost per test, but also in managing the quality of the services.
Principles for the Prevention and Intervention of Mathematics Difficulties
Authors: Fuchs Lynn S. , Fuchs Douglas 
Published: March 2003

Three levels of prevention and intervention in the area of mathematics are addressed: (a) primary prevention focusing on universal design, (b) secondary prevention focusing on adaptations, and (c) tertiary prevention focusing on intensive and explicit contextualization of skills–based instruction. The purpose of this paper is to identify and discuss principles of prevention and intervention in the area of mathematics. First, we identify research–based principles associated with primary prevention. Second, we turn our attention to secondary prevention, with a focus on prereferral intervention. We identify principles that serve to differentiate primary and secondary prevention and specify instructional variables that are promising for use within a secondary prevention mode. Finally, we discuss intervention. We identify principles of effective intervention, which include individually referenced decision making, instructional intensity, and deliberate contextualization of skills–based instruction.
The Risk Balls Game: Transforming Risk and Insurance Into Tangible Concepts
Authors: Baranoff Etti G. 
Published: March 2003

AbstractThe Risk Balls game is used as a game in an introductory insurance course to demonstrate in a tangible way the notion of risk and its relationship to insurance. Through playing with the ``risk balls,'' each one representing a different type of risk, the students experience feelings of anxiety about risk, and later, the sense of anxiety reduction when they transfer the risk balls to insurers. The game incorporates complex concepts of risk transfer and risk reduction via pooling and sharing of risk. The mathematical implications of the law of large numbers are physically felt in the classroom when the students experience the relief associated with transferring the risk balls to insurers. The discussion that ensues during the game includes aspects of the underwriting process; moral hazard; adverse selection; the role of agents, insurers, and regulators; and the nature of the insurance contract. The game of risk balls stimulates lively group discussions and provides hands‐on experience with risks such as premature death risk or fire risk and the fears associated with them.
The multiple self: working with dissociation and trauma
Authors: Everest Pauline 
Published: March 2003

This paper describes a patient who appears to have a chronic dissociative personality disorder. Renewed clinical interest in dissociative disorders had arisen in North America in the 1980s, in part due to the influence of the Women's Movement which had highlighted the incidence of child sexual abuse. The early psychological observations of Janet, Freud and Jung on hysterical patients who displayed dissociative phenomena were similar to those displayed by the patient. Consideration is given to theoretical understanding of the condition, taking into account the views of the earlier theorists and object‐relations theory.The possibility of trauma, in particular childhood sexual abuse, as a causative factor in dissociative disorders is discussed.
The Heckman Correction for Sample Selection and Its Critique
Authors: Puhani Patrick 
Published: March 2003

This paper gives a short overview of Monte Carlo studies on the usefulness of Heckman’s (1976, 1979) two‐step estimator for estimating selection models. Such models occur frequently in empirical work, especially in microeconometrics when estimating wage equations or consumer expenditures.It is shown that exploratory work to check for collinearity problems is strongly recommended before deciding on which estimator to apply. In the absence of collinearity problems, the full‐information maximum likelihood estimator is preferable to the limited‐information two‐step method of Heckman, although the latter also gives reasonable results. If, however, collinearity problems prevail, subsample OLS (or the Two‐Part Model) is the most robust amongst the simple‐to‐calculate estimators.