bluuebunny/crossref_metadata_2025 huggingface dataset:
Atypical small acinar proliferation: biopsy artefact or distinct pathological entity?
Authors: Flury Sarah C. , Galgano Mary T. , Mills Stacey E. , Smolkin Mark E. , Theodorescu Dan
Published: January 2007

OBJECTIVE

To determine if atypical small acinar proliferation (ASAP) represents minimally sampled prostate cancer not fully evaluated on a biopsy or a distinct pathological entity, by examining prostates removed at radical cystectomy, as a finding of ASAP of the prostate on needle‐core biopsy is closely associated with the detection of cancer on subsequent biopsy.

PATIENTS AND METHODS

In all, 65 consecutive cystoprostatectomy specimens taken from June 1990 to March 2004 had prostatic material reviewed by one genitourinary pathologist (S.E.M.). The presence of high‐grade prostatic intraepithelial neoplasia (HGPIN), ASAP, and adenocarcinoma was recorded. Foci of ASAP found in the absence of cancer were assessed with additional sectioning, high‐molecular weight keratin (CK903), and α‐methylacyl coenzyme A racemase (AMACR) immunohistochemistry.

RESULTS

In all, 24 of 65 specimens (37%) had adenocarcinoma. Of the 41 without cancer, 18 (44%) had neither HGPIN nor ASAP, 14 (34%) had HGPIN alone, three (7%) had ASAP alone (four foci), and six had both HGPIN and ASAP (15%). Two foci of ASAP were not present on any further sectioning. The remaining eight foci all lacked CK903 stain, indicating disruption of the basal cell layer. Of these eight, only five were present for the AMACR stain, all of which were positive. Two of these five developed into a lesion considered cancer on further sectioning.

CONCLUSION

ASAP identified in incidental prostates represented marginally sampled cancer in at least two of 10 foci assessed. The remainder could not be resolved as benign on further evaluation, and remained suspicious for malignancy.
A Comparison of the Variability Spectra of Two Genomic Loci in a European Group of Individuals Reveals Fundamental Differences Pointing to Selection or a Population Bottleneck
Authors: Schmegner C. , Hoegel J. , Vogel W. , Assum G.
Published: January 2007

Knowledge about the variability spectra of neutrally evolving sequences in a population is a prerequisite for the identification of genes, which may have been under positive selection during recent human evolution. Here, we report the results of a re‐sequencing project of a presumably neutrally evolving chromosome 22 locus with a severely reduced recombination frequency in a group of 24 individuals of German origin. The comparison of these data with the results of a similar analysis of a chromosome 17 locus revealed striking differences, although the same group of individuals was used. For the chromosome 17 locus two well‐separated groups of sequences, a positive value of Tajima's D and a TMRCA of 700 000 years were observed. In contrast, the sequences from the chromosome 22 locus were found to be relatively homogeneous, with no deep splits between subgroups; the obtained value for Tajima's D was negative and the TMRCA was only 260 000 years. These discrepancies may be explained by selection or demographic processes. Regarding demography, the most plausible explanation is the assumption of a severe bottleneck in the history of the European population: in the case of the chromosome 17 locus two ancient lineages passed this bottleneck; for the chromosome 22 locus it was only one ancient lineage.
The effect of videokeratoscope faceplate design on radius of curvature maps
Authors: Monteiro P. M. L. , Hull C. C.
Published: January 2007

A computer model using finite ray tracing methods was developed to simulate a videokeratoscope analysing an average cornea. Different faceplate designs were tested using five points on the faceplate subtending angles at the corneal vertex between 15° and 75° in 15° intervals. Image quality was assessed by adding the geometrical blurs of the five image points. Differences (error) between true sagittal radius of curvature, and sagittal radius of curvature calculated by the van Saarloos algorithm, were calculated for selected surfaces at the same corneal points. Differences equal to or bigger than 0.02 mm were regarded as clinically significant. The faceplate surface that provided the sharpest image for an average cornea was a cylinder with the base 120 mm away from the corneal vertex and a diameter of 26 mm. Changing the faceplate design results in clinically significant differences for an average cornea. Image quality is not proportional to corneal surface reconstruction accuracy.
Microbial contamination of contact lenses and lens care accessories of soft contact lens wearers (university students) in Hong Kong
Authors: Yung M. S. , Boost M. , Cho P. , Yap M.
Published: January 2007

Purpose:  This study aimed to examine the rates of microbial contamination, and identify contaminants associated with contact lenses and lens care accessories used by a group of young contact lens wearers.

Methods:  Collected contact lenses, lens cases, and lens care solutions were studied by bacterial culture. Contamination rates of these samples were recorded and compared with those reported in previous studies.

Results:  Of the samples tested, 9% of lens extracts, 34% of case extracts and 11% of solution samples were contaminated with ocular pathogenic microorganisms. Serratia spp., Staphylococcus aureus and coagulase‐negative staphylococci were the most common microorganisms isolated. Lens cases were the most frequently contaminated item. Lens cases also yielded the widest range of bacterial isolates. Contact lenses used by occasional wearers were associated with a higher contamination rate. Using either saline or multipurpose solution to rinse lenses before use appeared to be effective in reducing incidence of contamination.

Conclusion:  Our findings demonstrate that contact lenses and lens care accessories are not well maintained by contact lens wearers. Regular reviews and reinforcement of lens care procedures for the usage and care of contact lenses and lens care accessories is therefore important and essential.
Objective vs subjective measurements of dark vergence
Authors: Jaschinski Wolfgang , Jainta Stephanie , Hoormann Jörg , Walper Nina
Published: January 2007

Dark vergence is a resting position of vergence (tonic vergence), measured in a dark visual field to eliminate fusional, accommodative, and proximal stimuli. The vergence resting position is relevant for measures of phoria and fixation disparity. Dark vergence differs reliably among subjects: the average subject converges at a viewing distance of about 1 m, while the inter‐individual range is from infinity to about 40 cm. In previous research, dark vergence was measured subjectively, i.e. observers adjusted the horizontal offset of dichoptically presented nonius targets to perceived alignment. Results of such subjective vergence tests do not necessarily agree with those of the objective measurements of eye position with eye trackers. Therefore, we made simultaneous subjective and objective measurements of dark vergence and found similar results with both methods in repeated tests in two sessions. Thus, the nonius test is sufficient for a subjective estimation of dark vergence.
Pharmacological Profile of the 5‐HT2C Receptor Agonist WAY‐163909; Therapeutic Potential in Multiple Indications
Authors: Dunlop John , Marquis Karen L. , Lim HK , Leung Louis , Kao John , Cheesman Cynthia , Rosenzweig‐Lipson Sharon
Published: January 2007

The 5‐HT2C receptor subtype has been implicated in a wide variety of conditions including obesity, anxiety, depression, obsessive compulsive disorder, schizophrenia, migraine and erectile dysfunction and as a consequence has received considerable attention as a target for drug discovery. Here we review the pharmacological, pharmacokinetic and toxicological profile of WAY‐163909 {(7bR,10aR)‐1,2,3,4,8,9,10,10a‐octahydro‐7bH‐cyclopenta‐[b][1,4]diazepino[6,7,1hi]indole}, a novel 5‐HT2C receptor selective agonist. Consistent with a potential therapeutic utility in obesity, schizophrenia and depression WAY‐163909 was found to have robust dose‐dependent effects in animal models of obesity, psychotic‐like behavior or depression.
The Bond Strength of Particulate‐Filler Composite to Differently Oriented Fiber‐Reinforced Composite Substrate
Authors: Lassila Lippo V.J. , Tezvergil Arzu , Dyer Scott R. , Vallittu Pekka K.
Published: January 2007

Purpose: The primary failure mode of fiber‐reinforced composite (FRC) materials used intraorally is delamination or debonding of particulate filler composite (PFC), the esthetic veneer, from the underlying FRC framework. The objective of the current study was to evaluate the effect of unidirectional fiber orientation and load direction on the shear bond strength of PFC to FRC.

Materials and Methods: Unidirectional E‐glass FRC was used as an adhesion substrate for the PFC. E‐glass FRCs were oriented in three ways—Group A: in the plane perpendicular to the bonding surface; Group B: along the bonding surface longitudinal to the load; and Group C: along the bonding surface, transverse to the load. The FRC substrates were ground flat with 1200 grit. The PFC adherend was bonded to FRC using an intermediate resin. Twelve specimens for each group were water stored (37°C) for 3 days before a shear bond strength test was conducted.

Results: A one‐way analysis of variance showed that the direction of the applied load to the fiber direction had a significant effect on the bond strength values (p < 0.001). A Weibull analysis produced values (characteristic strength and Weibull modulus) of Group A (46.5 MPa, 12.1), Group B (40.6 MPa, 4.6), and Group C (27.6 MPa, 3.5).

Significance: The highest shear bond strength values and Weibull modulus were obtained when the fibers were oriented perpendicular to the bonding surface, exposing the fiber ends to the PFC. Interface strategies between hybrid composite layers may be developed to exploit anisotropic behavior in the adherence between FRC and PFC.
In Vitro Evaluation of Five Core Materials
Authors: Gu Steven , Rasimick Brian J. , Deutsch Allan S. , Musikant Barry L.
Published: January 2007

Purpose: This in vitro study determined the fracture strength of five core materials supported by two different endodontic dowels. Diametral tensile strength and microhardness of the three resin composite core materials used in this study were also tested.

Material and Methods: The fracture strength study used one lanthanide‐reinforced flowable resin composite (Ti‐Core Auto E), one titanium‐ and lanthanide‐reinforced composite (Ti‐Core), one lanthanide‐reinforced composite (Ti‐Core Natural), and two metal‐reinforced glass ionomer core materials (Ketac Silver and GC Miracle Mix). Two types of dowels were used: a multitiered, split‐shank threaded dowel with a flange (#1 Flexi‐Flange) and one without a flange design (#1 Flexi‐Post). The specimens were divided into ten groups. Each tooth/dowel and core specimen was placed in a special jig at 45° and subjected to a load by a universal testing machine. The diametral tensile strength and the microhardness of the three resin composite core materials were measured by a universal testing machine and Barcol hardness tester, respectively. All test groups contained ten specimens.

Results: The fracture strength value of the resin composite core materials was significantly larger ( p < 0.0001) than those for the metal‐reinforced glass‐ionomer core materials. Analysis of variance (ANOVA) also showed that the Flexi‐Flange dowel interacted with Ti‐Core and Ti‐Core Auto E to significantly ( p < 0.0013) increase the fracture strength relative to the Flexi‐Post. One‐way ANOVA revealed that there were no significant differences between them in terms of diametral tensile strength. The Barcol hardness values of the composite core materials were statistically different ( p < 0.0001), with the Ti‐Core the highest, followed by Ti‐Core Natural, then Ti‐Core Auto E.

Conclusions: Resin composite core material performed better than glass ionomer material in this in vitro study. The flowable composite core material performed about the same in terms of fracture strength and diametral tensile strength compared with nonflowable composites. Combined with certain core materials, the flange design increased the fracture strength of the tooth/dowel and core combination.
Human cord blood CD133+ cells immunoselected by a clinical‐grade apparatus differentiate in vitro into endothelial‐ and cardiomyocyte‐like cells
Authors: Bonanno Giuseppina , Mariotti Andrea , Procoli Annabella , Corallo Maria , Rutella Sergio , Pessina Gloria , Scambia Giovanni , Mancuso Salvatore , Pierelli Luca
Published: January 2007

BACKGROUND: Recent findings on human hematopoietic stem cell (HSC) properties suggest a possible therapeutic role of human umbilical cord blood (UCB) HSC‐based cellular therapies in the treatment of myocardial infarction.

STUDY DESIGN AND METHODS: Nine UCB units were subjected to sequential red cell removal, freezing, and postthawing CD133+ HSC immunoselection by a clinical‐grade, CE‐approved, magnetic apparatus and microbead‐coated anti‐CD133 monoclonal antibody. Selected UCB CD133+ cells were cultured in vitro in medium supporting either endothelial or cardiomyocytic differentiation in parallel experiments.

RESULTS: Immunoselection allowed recovery of 79 percent of initial CD133+ cells with a CD133+ cell purity of 81 percent, on average. Parallel cultures showed the appearance of endothelial markers (VE‐cadherin, CD146, and KDR and bright expression of CD105), morphofunctional features of endothelium in endothelial‐supporting cultures, of cardiac muscle proteins (troponin I and myosin ventricular heavy chain α/β; MYHC) and specific gene expression (GATA4, NKX2.5, troponin I, and MYHC) in cardiomyocyte‐oriented cultures.

CONCLUSIONS: The appearance of both endothelial‐ and cardiomyocyte‐like cells from parallel cultures of frozen‐thawed‐immunoselected UCB CD133+ cells by a clinical‐grade method and previously reported data on lack of major signs of rejection of these cells in immunocompetent rats subjected to experimental liver damage suggest a possible role of these allogeneic HSCs in cell therapies designed for regenerative treatments of ischemic diseases of human myocardium.
Functional in vitro studies of recombinant human immunoglobulin G and immunoglobulin A anti‐D
Authors: Nielsen Leif Kofoed , Green Trine Hefsgaard , Norderhaug Lars , Sandlie Inger , Dziegiel Morten Hanefeld
Published: January 2007

BACKGROUND: The use of anti‐D purified from human serum to prevent hemolytic disease of the fetus and newborn due to D is well established. Owing to supply and safety reasons, however, an unlimited and non–plasma‐derived source of antibodies for Rhesus prophylaxis is needed.

STUDY DESIGN AND METHODS: Recombinant human immunoglobulin G (IgG)1, IgG2, IgG3, IgG4, IgA1, and IgA2 anti‐D with the same variable region were expressed in Chinese hamster ovary cells. The effector functions of these antibodies were assessed by an antibody‐dependent cell‐mediated cytotoxicity (ADCC) assay and a chemiluminescence (CL) method for detection of respiratory burst.

RESULTS: In the ADCC assay, IgG1, IgG3, and IgA1 did the best and were as active as a currently used prophylactic polyclonal anti‐D. IgG4 and IgA2 were moderately active, whereas IgG2 was not active. In the CL assay, IgG1 and IgG3 were active but much less so than a currently used prophylactic polyclonal anti‐D. For some effector cell preparations, IgG4 was active in the CL assay, whereas IgG2, IgA1, and IgA2 were not. A mixture of IgG1 and IgG3 showed a synergistic effect in the CL assay and did as well as the prophylactic polyclonal anti‐D in ADCC and CL. Mixtures of IgA1 and either IgG1 or IgG3 showed no synergistic effect.

CONCLUSION: A mixture of recombinant human IgG1 and IgG3 anti‐D could be of value in future Rhesus prophylaxis.
Current incidence and estimated residual risk of transfusion‐transmitted infections in donations made to Canadian Blood Services
Authors: O'Brien Sheila F. , Yi Qi‐Long , Fan Wenli , Scalia Vito , Kleinman Steven H. , Vamvakas Eleftherios C.
Published: January 2007

BACKGROUND: New testing methods such as nucleic acid amplification testing (NAT) and chemiluminescent serologic assays have been introduced, more precise estimates for infectious window periods are available, and a new method for estimating the residual risk (RR) of transfusion‐transmitted infections (TTIs) has been developed. Thus, available RR estimates for Canada need to be updated.

STUDY DESIGN AND METHODS: Incidence rates for known TTI markers were determined for all allogeneic whole‐blood donations made to Canadian Blood Services between 2001 and 2005; they were derived from NAT conversions or seroconversions of repeat donors with at least two donations in a 3‐year period. RR estimates for human immunodeficiency virus (HIV)‐1 and hepatitis C virus (HCV) derived from the classical incidence/window‐period model were compared to those obtained by the new method that estimates incidence from NAT‐positive, antibody‐negative donations (NAT‐yield cases) from all donors divided by person‐years.

RESULTS: With the classical method, the RR of HIV (1 per 7.8 million donations) and HCV (1 per 2.3 million) were low; HBV RR was higher (1 per 153,000). HCV RR was significantly lower when estimated with the new method (1 per 13 million). Eleven HCV NAT‐yield cases were predicted by applying the classical method to our seroconversion data but only 2 were observed (p = 0.011). Observed HIV‐1 NAT‐yield cases (n = 1) matched those predicted (n = 0.7).

CONCLUSION: New tests have reduced an already low risk of TTI in Canada. HCV RR estimates by two different methods differed but both were low.
Assessing exclusionary power of a paternity test involving a pair of alleged grandparents
Authors: Scarpetta Marco A. , Staub Rick W. , Einum David D.
Published: January 2007

BACKGROUND: The power of a genetic test battery to exclude a pair of individuals as grandparents is an important consideration for parentage testing laboratories. However, a reliable method to calculate such a statistic with short‐tandem repeat (STR) genetic markers has not been presented.

STUDY DESIGN AND METHODS: Two formulae describing the random grandparents not excluded (RGPNE) statistic at a single genetic locus were derived: RGPNE = a(4 − 6a + 4a2– a3) when the paternal obligate allele (POA) is defined and RGPNE = 2[(a + b)(2 − a − b)][1 − (a + b)(2 − a − b)] + [(a + b)(2 − a − b)] when the POA is ambiguous. A minimum number of genetic markers required to yield cumulative RGPNE values of not greater than 0.01 was calculated with weighted average allele frequencies of the CODIS STR loci. RGPNE data for actual grandparentage cases are also presented to empirically examine the exclusionary power of routine casework.

RESULTS: A comparison of RGPNE and random man not excluded (RMNE) values demonstrates the increased difficulty involved in excluding two individuals as grandparents compared to excluding a single alleged parent. A minimum of 12 STR markers is necessary to achieve RGPNE values of not greater than 0.01 when the mother is tested; more than 25 markers are required without the mother. Cumulative RGPNE values for each of 22 nonexclusionary grandparentage cases were not more than 0.01 but were significantly weaker when calculated without data from the mother.

CONCLUSION: Calculation of the RGPNE provides a simple means to help minimize the potential of false inclusions in grandparentage analyses. This study also underscores the importance of testing the mother when examining the parents of an unavailable alleged father (AF).
The First MBA President: George W. Bush as Public Administrator
Authors: Pfiffner James P.
Published: January 2007

President Bush was praised early in his first term as a tough‐minded decision maker who knows how to get things done. This essay argues that President Bush possesses formidable political skills that have helped him achieve many of his policy goals, focusing on his most important national security policies: the war in Iraq, the war on terrorism and the treatment of detainees, the use of intelligence leading up to the war, and the reorganization of the executive branch. In the end, however, President Bush’s deficiencies as a public administrator have undermined his policy successes.
Three Bush Administration Management Reform Initiatives: The President’s Management Agenda, Freedom to Manage Legislative Proposals, and the Program Assessment Rating Tool
Authors: Breul Jonathan D.
Published: January 2007

In response to the foregoing essay by James P. Pfiffner on President George W. Bush’s legacy as a public administrator, this essay takes a practical look at three government‐wide Bush administration management reform initiatives: the President’s Management Agenda, the Freedom to Manage legislative proposals, and the Program Assessment Rating Tool.
The Effects of Social Support on Work–Family Enhancement and Work–Family Conflict in the Public Sector
Authors: Wadsworth Lori L. , Owens Bradley P.
Published: January 2007

This study examines the impact of social support on work–family conflict and work–family enhancement. Data from 341 employees of public organizations showed that social support, especially from work sources, reduced the level of work interference with family, one direction of work–family conflict. In addition, all nonfamily sources of social support related positively to work enhancement of family, and all sources of social support, except that received from a supervisor, positively correlated with family enhancement of work. The strengths, limitations, and implications of the study are discussed, and areas for future research are recommended.
Spirituality and Public Service
Authors: Houston David J. , Cartwright Katherine E.
Published: January 2007

The common pronouncement of a career in public service as a “calling” echoes with a decidedly spiritual chord. However, the spiritual roots of public service have been ignored in much of the public administration scholarship. This essay examines the empirical connection between individual spirituality and participation in public service occupations. Data from the 1998 General Social Survey are analyzed to determine whether those in public service occupations are more spiritual than persons in non–public service occupations. The findings indicate that individuals in public service occupations, especially government‐related ones, are in fact more spiritual in their attitudes than others. Moreover, belief in the notions of transcendence and compassion for others are more pronounced in public service employees. Finally, the experience of interconnectedness and life meaning is greater for those in the public service.
The Capacities and Challenges of Faith‐Based Human Service Organizations
Authors: Clerkin Richard M. , Grønbjerg Kirsten A.
Published: January 2007

This essay addresses four questions by comparing the management capacities and challenges of congregations, faith‐based organizations, and secular organizations that provide human services: (1) What role, if any, do congregations and faith‐based organizations currently play in the social service delivery system? (2) Are congregations interested in changing their role in the social service delivery system? (3) Compared to faith‐based and secular organizations, do congregations have the capacity to adapt to new roles in the social service delivery system? Finally, (4) compared to faith‐based and secular organizations, do congregations have similar service capacities and management challenges? The findings indicate that although more than half of congregations already provide some type of health or human services, they provide a narrower range of services, consider these services a lower priority, and seem to encounter more extensive management challenges than faith‐based and secular organizations.
Trading Volume: Implications of an Intertemporal Capital Asset Pricing Model
Authors: LO ANDREW W. , WANG JIANG
Published: January 2007

We derive an intertemporal asset pricing model and explore its implications for trading volume and asset returns. We show that investors trade in only two portfolios: the market portfolio, and a hedging portfolio that is used to hedge the risk of changing market conditions. We empirically identify the hedging portfolio using weekly volume and returns data for U.S. stocks, and then test two of its properties implied by the theory: Its return should be an additional risk factor in explaining the cross section of asset returns, and should also be the best predictor of future market returns.
Model Uncertainty and Option Markets with Heterogeneous Beliefs
Authors: BURASCHI ANDREA , JILTSOV ALEXEI
Published: January 2007

This paper provides option pricing and volume implications for an economy with heterogeneous agents who face model uncertainty and have different beliefs on expected returns. Market incompleteness makes options nonredundant, while heterogeneity creates a link between differences in beliefs and option volumes. We solve for both option prices and volumes and test the joint empirical implications using S&P500 index option data. Specifically, we use survey data to build an Index of Dispersion in Beliefs and find that a model that takes information heterogeneity into account can explain the dynamics of option volume and the smile better than can reduced‐form models with stochastic volatility.
Tax‐Loss Selling and the January Effect: Evidence from Municipal Bond Closed‐End Funds
Authors: STARKS LAURA T. , YONG LI , ZHENG LU
Published: January 2007

This paper provides direct evidence supporting the tax‐loss selling hypothesis as an explanation of the January effect. Examining turn‐of‐the‐year return and volume patterns for municipal bond closed‐end funds, which are held mostly by tax‐sensitive individual investors, we document a January effect for these funds, but not for their underlying assets. We provide evidence that this effect can be largely explained by tax‐loss selling activities at the previous year‐end. Moreover, we find that funds associated with brokerage firms display more tax‐loss selling behavior, suggesting that tax counseling plays a role.
Can Mutual Fund “Stars” Really Pick Stocks? New Evidence from a Bootstrap Analysis
Authors: KOSOWSKI ROBERT , TIMMERMANN ALLAN , WERMERS RUSS , WHITE HAL
Published: January 2007

We apply a new bootstrap statistical technique to examine the performance of the U.S. open‐end, domestic equity mutual fund industry over the 1975 to 2002 period. A bootstrap approach is necessary because the cross section of mutual fund alphas has a complex nonnormal distribution due to heterogeneous risk‐taking by funds as well as nonnormalities in individual fund alpha distributions. Our bootstrap approach uncovers findings that differ from many past studies. Specifically, we find that a sizable minority of managers pick stocks well enough to more than cover their costs. Moreover, the superior alphas of these managers persist.
Why Is Long‐Horizon Equity Less Risky? A Duration‐Based Explanation of the Value Premium
Authors: LETTAU MARTIN , WACHTER JESSICA A.
Published: January 2007

We propose a dynamic risk‐based model that captures the value premium. Firms are modeled as long‐lived assets distinguished by the timing of cash flows. The stochastic discount factor is specified so that shocks to aggregate dividends are priced, but shocks to the discount rate are not. The model implies that growth firms covary more with the discount rate than do value firms, which covary more with cash flows. When calibrated to explain aggregate stock market behavior, the model accounts for the observed value premium, the high Sharpe ratios on value firms, and the poor performance of the CAPM.
Corporate Yield Spreads and Bond Liquidity
Authors: CHEN LONG , LESMOND DAVID A. , WEI JASON
Published: January 2007

We find that liquidity is priced in corporate yield spreads. Using a battery of liquidity measures covering over 4,000 corporate bonds and spanning both investment grade and speculative categories, we find that more illiquid bonds earn higher yield spreads, and an improvement in liquidity causes a significant reduction in yield spreads. These results hold after controlling for common bond‐specific, firm‐specific, and macroeconomic variables, and are robust to issuers' fixed effect and potential endogeneity bias. Our findings justify the concern in the default risk literature that neither the level nor the dynamic of yield spreads can be fully explained by default risk determinants.
Learning by Observing: Information Spillovers in the Execution and Valuation of Commercial Bank M&As
Authors: DELONG GAYLE , DEYOUNG ROBERT
Published: January 2007

We offer a new explanation for why academic studies typically fail to find value creation in bank mergers. Our conjectures are predicated on the idea that, until recently, large bank acquisitions were a new phenomenon, with no best practices history to inform bank managers or market investors. We hypothesize that merging banks, and investors pricing bank mergers, learn by observing information that spills over from previous bank mergers. We find evidence consistent with these conjectures for 216 M&As of large, publicly traded U.S. commercial banks between 1987 and 1999. Our findings are consistent with semistrong stock market efficiency.
A Theory of Friendly Boards
Authors: ADAMS RENÉE B. , FERREIRA DANIEL
Published: January 2007

We analyze the consequences of the board's dual role as advisor as well as monitor of management. Given this dual role, the CEO faces a trade‐off in disclosing information to the board: If he reveals his information, he receives better advice; however, an informed board will also monitor him more intensively. Since an independent board is a tougher monitor, the CEO may be reluctant to share information with it. Thus, management‐friendly boards can be optimal. Using the insights from the model, we analyze the differences between sole and dual board systems. We highlight several policy implications of our analysis.
The Initial Public Offerings of Listed Firms
Authors: DERRIEN FRANÇOIS , KECSKÉS AMBRUS
Published: January 2007

A number of firms in the United Kingdom list without issuing equity and then issue equity shortly thereafter. We argue that this two‐stage offering strategy is less costly than an initial public offering (IPO) because trading reduces the valuation uncertainty of these firms before they issue equity. We find that initial returns are 10% to 30% lower for these firms than for comparable IPOs, and we provide evidence that the market in the firm's shares lowers financing costs. We also show that these firms time the market both when they list and when they issue equity.
Market Underreaction to Free Cash Flows from IPOs
Authors: Zheng Steven X.
Published: January 2007

I examine the relation between initial public offering (IPO) long‐run stock performance and the amount of cash raised by the firm in the offering. I find that IPOs raising more cash have poorer long‐run performance. The result is robust to different measurement methods. The evidence suggests that the market underreacts to free cash flow related agency problems in IPOs. Consistent with this interpretation, I find that IPO long‐run performance is more sensitive to the new cash raised in the offering if an IPO firm has lower capital expenditure or higher opening bid‐ask spread.
CEO Cash and Stock‐Based Compensation Changes, Layoff Decisions, and Shareholder Value
Authors: Brookman Jeffrey T. , Chang Saeyoung , Rennie Craig G.
Published: January 2007

The chief executive officers (CEOs) of firms announcing layoffs receive 22.8% more total pay in the subsequent year than other CEOs. The pay increases result almost entirely from increases in stock‐based compensation and are found to persist. In addition, layoff announcements are accompanied by shareholder value increases averaging $40 million to $95 million. One‐time labor cost savings from layoffs average $65 million. We conclude that CEOs receive pay increases following layoffs as rewards for past decisions and to motivate value‐enhancing decisions in the future.
Repricing and Executive Turnover
Authors: Subramanian Narayanan , Chakraborty Atreya , Sheikh Shahbaz
Published: January 2007

We examine whether the threat of executive turnover faced by a firm affects its decision to reprice stock options held by its executives. We estimate a model of voluntary turnover among top executives and show that the predicted turnover from this model is positively related to the probability of repricing. The relationship is robust to the inclusion of several known determinants of repricing. Our results are consistent with a model in which a tight labor market makes executives hard to replace, forcing firms to reprice stock options when they go underwater.
NGOs and Ethnic Conflict: Lessons from the Work of the Project on Ethnic Relations in the Balkans
Authors: Burg Steven L.
Published: January 2007

This article examines the impact of nongovernmental organization‐sponsored contact and communication on fostering peaceful solutions to ethnic conflict via case studies of the activities of the Project on Ethnic Relations (PER) in Romania, Macedonia, Montenegro, Kosovo, and Serbia. It explores five operational principles that guide PER activity: creating credible, neutral forums for dialogue; maintaining momentum; working within political realities; encouraging indigenous solutions from within existing processes; and acting with the backing of powerful states. These principles explain PER's success as a “weak mediator” of ethnic conflicts. According to this analysis, PER also exhibits organizational characteristics that contribute to success, including nonpartisanship, area expertise and extensive networks of local contacts, and an ability to secure the trust of local actors.

A significant indicator of the success of PER activities is the establishment by conflicting parties of institutionalized mechanisms for addressing their differences. Contrary to the view that electoral competition contributes to conflict, this study finds that the possibility of achieving an electoral advantage by participating cooperatively in conflict resolution activities creates incentives for local actors to recognize opportunities offered by PER activities and leads local actors to heed PER's advice. Finally, the article offers a cautionary observation. While PER's perceived influence with major international actors may contribute to its local successes, once a state actor with the power to impose a solution has committed itself to ending a conflict, its preferences outweigh any local interests in determining the outcome and renders the efforts of a “weak mediator” such as PER irrelevant.
Insight Mediation: A Learning‐Centered Mediation Model
Authors: Picard Cheryl A. , Melchin Kenneth R.
Published: January 2007

Insight mediation is the name we have given to the model of mediation that is taught and practiced at Carleton University in Ottawa, Canada. The name has evolved from our efforts to situate the model in relation to the transformative and narrative styles of mediation. Drawing upon the work of Canadian philosopher Bernard Lonergan and his theory of insight, mediators practicing this model seek direct and inverse insights into what the conflict means to each party by discovering what each party cares about and how that threatens the other party. Insights shift attitudes and create space for collective action. The authors argue that coming to recognize the theoretical underpinnings of our practice helps us become better practitioners.
Bone reconstruction following implantation of rhBMP‐2 and guided bone regeneration in canine alveolar ridge defects
Authors: Jovanovic Sascha A. , Hunt Dennis R. , Bernard George W. , Spiekermann Hubertus , Wozney John M. , Wikesjö Ulf M. E.
Published: January 2007

Background: Alveolar ridge aberrations commonly require bone augmentation procedures for optimal placement of endosseous dental implants. The objective of this study was to evaluate local bone formation following implantation of recombinant human bone morphogenetic protein‐2 (rhBMP‐2) in an absorbable collagen sponge (ACS) carrier with or without provisions for guided bone regeneration (GBR) as potential treatment modalities for alveolar augmentation.

Methods: Surgically induced, large, mandibular alveolar ridge saddle‐type defects (2 defects/jaw quadrant) in seven young adult Hound dogs were assigned to receive rhBMP‐2/ACS, rhBMP‐2/ACS combined with GBR (rhBMP‐2/GBR), GBR, and surgery controls. The animals were euthanized at 12 weeks post‐surgery when block sections of the defect sites were collected for histologic analysis.

Results: Clinical complications included swelling for sites receiving rhBMP‐2 and wound failure with exposure of the barrier device for sites receiving GBR (4/6) or rhBMP‐2/GBR (3/7). The radiographic evaluation showed substantial bone fill for sites receiving rhBMP‐2/ACS, rhBMP‐2/GBR, and GBR. In particular, sites receiving rhBMP‐2/GBR presented with seroma‐like radiolucencies. The surgery control exhibited moderate bone fill. To evaluate the biologic potential of the specific protocols, sites exhibiting wound failure were excluded from the histometric analysis. Sites receiving rhBMP‐2/ACS or rhBMP‐2/GBR exhibited bone fill averaging 101%. Bone fill averaged 92% and 60%, respectively, for sites receiving GBR and surgery controls. Bone density ranged from 50% to 57% for sites receiving rhBMP‐2/ACS, GBR, or surgery controls. Bone density for sites receiving rhBMP‐2/GBR averaged 34% largely due to seroma formation encompassing 13% to 97% of the sites.

Conclusion: rhBMP‐2/ACS appears to be an effective alternative to GBR in the reconstruction of advanced alveolar ridge defects. Combining rhBMP‐2/ACS with GBR appears to be of limited value due to the potential for wound failure or persistent seromas.
Success rate of mini‐ and micro‐implants used for orthodontic anchorage: a prospective clinical study
Authors: Wiechmann Dirk , Meyer Ulrich , Büchter André
Published: January 2007

Objectives: Whereas micro‐implants have become a useful alternative as orthodontic anchorage elements in orthodontics, less is known about the clinical effectiveness of micro‐implants. The aim of this prospective clinical study was to evaluate the success rate of micro‐implants used for orthodontic anchorage.

Material and methods: A total of 133 mini‐implants (79 Abso Anchor, 54 Dual Top implants) placed in 49 patients to support orthodontic tooth movements were examined in the study. The majority of the implants were placed in the maxilla (82), followed by the vestibular (42) and lingual (nine) aspect of the mandible.

Results: An overall cumulative survival rate of 86.8% (102/133) was found by Kaplan–Meier analysis. The failure rate between Dual Top implants (13%) and Abso Anchor implants (30.4%) differed significantly (P=0.0196; log‐rank test). The cumulative failure rate of implants was found to be significantly higher when implants were placed in the lingual aspect of the mandible compared with the other localizations (P=0.0011; log‐rank test). Clinical evaluation revealed successful dental movements when implants remained stable during the orthodontic therapy.

Conclusions: The present results confirm the effectiveness of orthodontic micro‐implants used as anchorage elements.
Early effect of platelet‐rich plasma on bone healing in combination with an osteoconductive material in rat cranial defects
Authors: Plachokova Adelina S. , Van Den Dolder Juliette , Stoelinga Paul J. , Jansen John A.
Published: January 2007

Objective: The early effect of platelet‐rich plasma (PRP) on bone regeneration in combination with dense biphasic hydroxyl apatite (HA)/β‐tricalcium phosphate (TCP) particles (ratio 60%/40%) was evaluated in rat cranial defects with a diameter of 6.2 mm. We hypothesize that PRP exerts its beneficial effect on bone regeneration within the first and second week after application in a bone defect combined with an osteoconductive material.

Materials and methods: Forty‐five rats were used in the study, in which always one cranial defect was created. The defects were filled with HA/β‐TCP particles and HA/β‐TCP particles combined with PRP gel. Some defects were also left unfilled as control. One and two weeks after surgery specimens were retrieved for light microscopy [hematoxylin–eosin, trichrome staining (Masson modification Goldner) and basic fuchsin‐methylene blue] and micro‐CT analysis to evaluate bone formation and neovascularization. One‐way analysis of variance was performed on the raw data obtained from micro‐CT analyses.

Results: The histological evaluation showed no effect of PRP on bone formation and neovascularization for both implantation times. In the first week, the defect closure was evaluated subjectively to be between 10% and 50% in all samples, whereas no difference among the groups appeared to occur. After 2 weeks, complete bridging of the original bone defect was observed for most of the empty defects, as well as for the defects that contained HA/β‐TCP particles. The trichrome staining revealed no difference in the number of blood vessels between the PRP and non‐PRP groups for both implantation times. The osteoconductive nature of dense HA/β‐TCP particles was confirmed, as the bone formation was guided by their outer surfaces and resulted in a larger amount of newly formed bone in comparison with the empty defects. The quantitative micro‐CT analysis demonstrated a statistically significant difference in new bone formation between the empty defects and defects filled with particles after 1 week of implantation, but there was no difference between the non‐PRP and PRP groups. In at the second week, no difference in bone formation among all groups was observed, whereas even the non‐filled control defects were almost completely closed.

Conclusions: A 6.2 mm cranial defect is not a critical‐sized defect in rats. Rat PRP had no effect on the early stages of bone healing in addition to an osteoconductive material. Dense HA/β‐TCP particles showed a beneficial effect on bone formation already after 1 and 2 weeks of implantation in non‐critical‐sized cranial defects in rats.
On the blue coloration of vertebrates†
Authors: Bagnara Joseph T. , Fernandez Philip J. , Fujii Royozo
Published: January 2007

Although the various vertebrate classes, from fishes to mammals are each distinctive, they possess many common features making it important to understand their comparative biology. One general feature that has long commanded interest is the integumental pigmentary system. Thus, much is known about particular pigment cells; however, the basis for some specific colors, such as blue, has escaped the scrutiny of the comparative approach. Regardless of Class, blue is almost always a structural color based upon incoherent or coherent scatter of blue wavelengths from the animal surface. The source of scatter may be intracellular or extra‐cellular. A main intracellular scatterer is the surface of reflecting platelets of iridophores of lower vertebrates. Extra‐cellular scatter is widespread and thought to occur from ordered dermal collagen arrays in primitive fishes, birds and mammals including humans. Among birds, feather structures provide major means for extra‐cellular light scatter. There is only one known example of blue color deriving from a blue pigment found within a pigment cell. For amphibians, reptiles and birds, the scatter of blue wavelengths, together with the presence of yellow pigmentation, is fundamental for the expression of green coloration.
Relationship between HLA Polymorphisms and Gamma Interferon and Interleukin-10 Cytokine Production in Healthy Individuals after Rubella Vaccination
Authors: Ovsyannikova Inna G. , Jacobson Robert M. , Ryan Jenna E. , Dhiman Neelam , Vierkant Robert A. , Poland Gregory A.
Published: January 2007

We studied the association between HLA alleles and rubella-specific gamma interferon (IFN-γ) (Th1) and interleukin-10 (IL-10) (Th2) cytokine responses among 106 healthy children (ages, 14 to 17 years) previously immunized with two doses of rubella vaccine. Antibody titers and cytokine responses to rubella vaccination were not sex or age dependent. Several class I HLA-A (*0201, *2402, *6801) alleles were significantly associated with rubella vaccine-induced IFN-γ secretion. Several class II HLA-DRB1 (*0101) and HLA-DQB1 (*0501) alleles were also suggestive of an association with IFN-γ secretion. Alleles with potential associations with rubella-specific IL-10 production included HLA-A (*0201, *6801), HLA-B (*4901), and HLA-DRB1 (*1302). The class I A*0201 and A*6801 alleles were associated with both IFN-γ and IL-10 secretion. These tentative associations need to be validated in larger studies with subjects of differing ethnicities. These results provide additional evidence that HLA genes may influence Th1- and Th2-specific cytokine response(s) following rubella immunization, which in turn can influence both cellular and humoral immune responses to rubella vaccination.
Characterization of
Anaplasma phagocytophilum
Major Surface Protein 5 and the Extent of Its Cross-Reactivity with
A. marginale
Authors: Strik N. I. , Alleman A. R. , Barbet A. F. , Sorenson H. L. , Wamsley H. L. , Gaschen F. P. , Luckschander N. , Wong S. , Chu F. , Foley J. E. , Bjoersdorff A. , Stuen S. , Knowles D. P.
Published: January 2007

Major surface protein 5 (Msp5) of
Anaplasma marginale
is highly conserved in the genus
Anaplasma
and the antigen used in a commercially available competitive enzyme-linked immunosorbent assay (cELISA) for serologic identification of cattle with anaplasmosis. This study analyzes the degrees of conservation of Msp5 among various isolates of
Anaplasma phagocytophilum
and the extent of serologic cross-reactivity between recombinant Msp5 (rMsp5) of
Anaplasma marginale
and
A. phagocytophilum
. The
msp5
genes from various isolates of
A. phagocytophilum
were sequenced and compared. rMsp5 proteins of
A. phagocytophilum
and
A. marginale
were used separately in an indirect ELISA to detect cross-reactivity in serum samples from humans and dogs infected with
A. phagocytophilum
and cattle infected with
A. marginale
. Serum samples were also tested with a commercially available competitive ELISA that uses monoclonal antibody ANAF16C1. There were 100% sequence identities in the
msp5
genes among all of the
A. phagocytophilum
isolates from the United States and a horse isolate from Sweden. Sheep isolates from Norway and dog isolates from Sweden were 99% identical to one another but differed in 17 base pairs from the United States isolates and the horse isolate. Serologic cross-reactivity was identified when serum samples from cattle infected with
A. marginale
were reacted with rMsp5 of
A. phagocytophilum
and when serum samples from humans and dogs infected with
A. phagocytophilum
were reacted with rMsp5 of
A. marginale
in an indirect-ELISA format. Serum samples from dogs or humans infected with
A. phagocytophilum
did not cross-react with rMsp5 of
A. marginale
when tested with the commercially available cELISA. These results suggest that rMsp5 of
A. phagocytophilum
is highly conserved among United States and European isolates and that serologic distinction between
A. phagocytophilum
and
A. marginale
infections cannot be accomplished if rMsp5 from either organism is used in an indirect ELISA.