bluuebunny/crossref_metadata_2025_split huggingface dataset:
Do Tests of Capital Structure Theory Mean What They Say?
Authors: STREBULAEV ILYA A. 
Published: August 2007

ABSTRACTIn the presence of frictions, firms adjust their capital structure infrequently. As a consequence, in a dynamic economy the leverage of most firms is likely to differ from the “optimum” leverage at the time of readjustment. This paper explores the empirical implications of this observation. I use a calibrated dynamic trade‐off model to simulate firms' capital structure paths. The results of standard cross‐sectional tests on these data are consistent with those reported in the empirical literature. In particular, the standard interpretation of some test results leads to the rejection of the underlying model. Taken together, the results suggest a rethinking of the way capital structure tests are conducted.
The Takeover Deterrent Effect of Open Market Share Repurchases
Authors: BILLETT MATTHEW T. , XUE HUI 
Published: August 2007

ABSTRACTThis paper examines whether open market share repurchases deter takeovers. We model pre‐repurchase takeover probability as a latent variable and examine its impact on the firm's decision to repurchase shares. Given specification tests reject the Tobit model, we turn to the censored quantile regression method of Powell (1986, Journal of Econometrics 32, 143–155). We find a significantly positive relation between open market share repurchases and takeover probability, and we reconcile empirical findings in previous studies that contradict predictions. Repurchase activity is inversely related to firm size, consistent with smaller firms having greater information asymmetry, and is related to temporary, but not permanent, cash flows.
Corporate Governance and Acquirer Returns
Authors: MASULIS RONALD W. , WANG CONG , XIE FEI 
Published: August 2007

ABSTRACTWe examine whether corporate governance mechanisms, especially the market for corporate control, affect the profitability of firm acquisitions. We find that acquirers with more antitakeover provisions experience significantly lower announcement‐period abnormal stock returns. This supports the hypothesis that managers at firms protected by more antitakeover provisions are less subject to the disciplinary power of the market for corporate control and thus are more likely to indulge in empire‐building acquisitions that destroy shareholder value. We also find that acquirers operating in more competitive industries or separating the positions of CEO and chairman of the board experience higher abnormal announcement returns.
Plaque Color Analysis by the Conventional Yellow‐Color Grading System and Quantitative Measurement Using LCH Color Space
Authors: OKADA KATSUKI , UEDA YASUNORI , OYABU JOTA , OGASAWARA NOBUYUKI , HIRAYAMA ATSUSHI , KODAMA KAZUHISA 
Published: August 2007

Background:
Yellow plaques of higher color grades are regarded as more vulnerable. We tried to elucidate the characteristics of yellow color that are regarded as the sign of vulnerable plaques by an objective and quantitative plaque color analysis.
Methods:
The color of yellow plaques was quantitatively analyzed using LCH color space and was presented by the maximum values of lightness (Lmax), chroma (Cmax), and hue (Hmax). Effect of light intensity on these parameters was experimentally examined (five plaque models, six light intensities). Relation between conventional yellow‐color grade and LCH parameters was examined (31 plaques). Color analysis with LCH color space was applied (1) to compare the culprit lesions of unstable angina (eight patients) and of stable effort angina (nine patients) and (2) to evaluate the regression of yellow plaque by 80‐week statin treatment (four patients, 19 plaques).
Results:
Cmax and Hmax were not influenced by light intensity so far as it was within appropriate range. Cmax (13 ± 3, 25 ± 5, and 28 ± 4) became higher and Hmax (178 ± 26, 134 ± 10, and 91 ± 16) became lower as the grade became higher (P < 0.0001). Culprit lesions of unstable angina had higher Cmax (22.8 ± 7.9 vs 14.8 ± 7.5, P = 0.04) and lower Hmax (73.3 ± 19.7 vs 168.0 ± 71.5, P = 0.002) than stable effort angina. Statin treatment reduced Cmax (21.3 ± 9.6 vs 14.6 ± 3.1, P = 0.004) and increased Hmax (82.6 ± 25.8 vs 142.3 ± 54.1, P = 0.0005).
Conclusions:
Plaque color was consistently and quantitatively measurable using LCH color space uninfluenced by light intensity of appropriate range. Vulnerable yellow color had high chroma and low hue, indicating vivid and reddish‐yellow color.
Measuring Diagnostic Competency and the Analysis of Factors Influencing Competency Using Written Case Studies
Authors: Hasegawa Tomoko , Ogasawara Chie , Katz Edmont C. 
Published: August 2007

PURPOSES. To measure nurses’ diagnostic competencies by using written case studies and to analyze factors influencing these competencies.METHODS. A descriptive study was conducted using survey methods and a mailed questionnaire with a convenience sample of 376 nurses. Two written case studies were used to measure the diagnostic competencies of the subjects. Possible factors influencing nurses’ judgments in making nursing diagnoses that were measured were clinical experience, decision‐making responsibility, knowledge of nursing diagnosis, and attitude toward the use of nursing diagnosis.FINDINGS. Subjects who demonstrated all three competencies were 35% (n = 131) for case study 1, and 53% (n = 200) for case study 2. Subjects who demonstrated diagnostic competency in defining diagnostic labels had the longest length of clinical experience. Subjects who were primary nurses with the usual responsibility of identifying nursing diagnoses showed the highest percentage of competency rates for defining characteristics, related factors, and risk factors.CONCLUSIONS. Many of these Japanese nurses did not perform at satisfactory levels of diagnostic competency with these two written case studies. Factors that influenced diagnostic competency were length of clinical experience, decision‐making responsibility, and frequency of studying nursing diagnosis.
Lake Nuga Nuga: a Levee‐dammed Lake in Central Queensland, Australia
Authors: FINLAYSON BRIAN , KENYON CHRISTINE 
Published: August 2007

AbstractLake Nuga Nuga is a levee‐dammed lake in the dry sub‐humid tropics of the Fitzroy Basin in Central Queensland, Australia, that has expanded significantly since it was first mapped in 1866. 210Pb dating of a sediment core from the lake indicates that the rate of sedimentation has been constant for the past 67 years at 3 mm yr−1 despite widespread clearing and land use intensification in the catchment during that time. Pollen analysis confirms this and shows that there was little change in vegetation during the early settlement period (1863–1962), but the intensification of land use that started in the early 1960s brought about a dramatic change in the vegetation communities. This study demonstrates that while sediment production may be significantly impacted by land‐use activities, sediment delivery is primarily controlled by topography.
Development and Validation of an Ovine Progressive Pneumonia Virus Quantitative PCR
Authors: Herrmann-Hoesing Lynn M. , White Stephen N. , Lewis Gregory S. , Mousel Michelle R. , Knowles Donald P. 
Published: August 2007

ABSTRACT

Ovine progressive pneumonia virus (OPPV) infects at least one sheep in 81% of U.S. sheep flocks, as determined by serology, and can cause viral mastitis, arthritis, dyspnea, and cachexia. Diagnostic tests that quantify OPPV proviral load in peripheral blood leukocytes (PBL) provide an additional method for identification of infected sheep and may help to further understanding of the pathogenesis of OPPV-induced disease. In this study, we compared a new OPPV real-time quantitative PCR (qPCR) assay specific for the transmembrane region of the envelope gene (
tm
) with a competitive inhibition enzyme-linked immunosorbent assay (cELISA) using 396 PBL samples and sera from Idaho sheep. The OPPV qPCR had a positive concordance of 96.2% ± 2.3% and a negative concordance of 97.7% ± 2.5% compared to the cELISA, with a kappa value of 0.93, indicating excellent agreement between the two tests. In addition, the presence of
tm
in the three OPPV qPCR-positive and cELISA-negative sheep and in 15 sheep with different OPPV proviral loads was confirmed by cloning and sequencing. These data indicate that the OPPV qPCR may be used as a supplemental diagnostic tool for OPPV infection and for measurement of viral load in PBLs of infected sheep.
Serum Immunoglobulin G Antibodies to the GOR Autoepitope Are Present in Patients with Occult Hepatitis C Virus (HCV) Infection despite Lack of HCV-Specific Antibodies
Authors: Quiroga Juan A. , Castillo Inmaculada , Bartolomé Javier , Carreño Vicente 
Published: August 2007

ABSTRACT

Antibody responses to the GOR autoepitope are frequently detected among anti-hepatitis C virus (anti-HCV)-positive patients with chronic hepatitis. Sera from 110 anti-HCV-negative patients with occult HCV infection, as diagnosed by detection of HCV RNA in hepatic tissue, were investigated for GOR antibody reactivity. A positive test for anti-GOR immunoglobulin G (IgG) was found for 22 (20%) of them. The frequency and titers of anti-GOR IgG were significantly lower than those in chronic hepatitis C patients (70/110, 63.6%;
P
< 0.001). Anti-GOR IgG was not detected in any of the 120 patients with HCV-unrelated liver disease. The anti-GOR IgG assay showed specificity and sensitivity values of 100% and 20%, respectively, among the sera from patients with occult HCV infection; the positive and negative predictive values were 100% and 44.3%, respectively. None of the clinical, laboratory, or histological characteristics of the patients with occult HCV infection were different according to GOR antibody status, except that the percentage of HCV RNA-positive hepatocytes was significantly greater (
P
= 0.042) in patients with occult HCV infection who tested positive for anti-GOR IgG. In conclusion, serum anti-GOR IgG is present in patients with occult HCV infection, despite a lack of detectable HCV-specific antibodies as determined by commercial tests. Testing for anti-GOR IgG in patients in whom HCV RNA is not detected in their sera may help with the identification of a subset of patients with occult HCV infection without the need to perform a liver biopsy.
Toll-Like Receptor 4 Polymorphism Associated with the Response to Whole-Cell Pertussis Vaccination in Children from the KOALA Study
Authors: Banus Sander , Bottema Renske W. B. , Siezen Christine L. E. , Vandebriel Rob J. , Reimerink Johan , Mommers Monique , Koppelman Gerard H. , Hoebee Barbara , Thijs Carel , Postma Dirkje S. , Kimman Tjeerd G. , Stelma Foekje F. 
Published: August 2007

ABSTRACT

We examined the association between haplotype tagging single-nucleotide polymorphisms in
TLR4
and the pertussis toxin-specific immunoglobulin G response after whole-cell pertussis (wP) vaccination in 515 1-year-old children from the KOALA study. A lower titer was associated with the minor allele of rs2770150, supporting a role for Toll-like receptor 4 in the antibody response to wP vaccination.
Pulsed-Field Gel Electrophoresis, Pertactin, Pertussis Toxin S1 Subunit Polymorphisms, and Surfaceome Analysis of Vaccine and Clinical
Bordetella pertussis
Strains
Authors: Bottero Daniela , Gaillard María Emilia , Fingermann Matías , Weltman Gabriela , Fernández Julieta , Sisti Federico , Graieb Augusto , Roberts Roy , Rico Osvaldo , Ríos Gustavo , Regueira Mabel , Binsztein Norma , Hozbor Daniela 
Published: August 2007

ABSTRACT

To add new insight to our previous work on the molecular epidemiology of
Bordetella pertussis
in Argentina, the
prn
and
ptxS1
gene sequences and pulsed-field gel electrophoresis (PFGE) profiles of 57 clinical isolates obtained during two periods, 1969 to 1989 and 1997 to 2006, were analyzed. Non-vaccine-type
ptxS1A
was detected in isolates obtained since 1969. From 1989 on, a shift of predominance from the vaccine
prn1
type to the nonvaccine
prn2
type was observed. This was also reflected in a transition of PFGE group IV to group VI. These results show that nonvaccine
B. pertussis
strains are currently circulating. To analyze whether the observed genomic divergences between vaccine strains and clinical isolates have functional implications, protection assays using the intranasal mouse challenge model were performed. For such experiments, the clinical isolate
B. pertussis
106 was selected as representative of circulating bacteria, since it came from the major group of the PFGE dendrogram (PFGE group VI). Groups of mice were immunized either with diphtheria-tetanus-whole-cell pertussis vaccine (
ptxS1B prn1
) or a vaccine prepared by us containing
B. pertussis
106. Immunized mice were then challenged with a
B. pertussis
vaccine strain (Tohama, harboring
ptxS1B
and
prn1
) or the clinical isolate
B. pertussis
106 (
ptxS1A prn2
). An adequate bacterial-elimination rate was observed only when mice were immunized and challenged with the same kind of strain. For further characterization, comparative proteomic profiling of enriched membrane proteins was done using three vaccine strains and the selected
B. pertussis
106 clinical isolate. By matrix-assisted laser desorption ionization-time of flight mass spectrometry analysis, a total of 54 proteins were identified. This methodology allowed us to detect differing proteins among the four strains studied and, in particular, to distinguish the three vaccine strains from each other, as well as the vaccine strains from the clinical isolate. The differing proteins observed have cellular roles associated with amino acid and carbohydrate transport and metabolism. Some of them have been proposed as novel vaccine candidate proteins for other pathogens. Overall, the global strategy described here is presented as a good tool for the development of next-generation acellular vaccines.
Case of Keratitis Caused by
Aspergillus tamarii
Authors: Kredics László , Varga János , Kocsubé Sándor , Dóczi Ilona , Samson Robert A. , Rajaraman Revathi , Narendran Venkatapathy , Bhaskar Madhavan , Vágvölgyi Csaba , Manikandan Palanisamy 
Published: August 2007

ABSTRACT

We report a case of
Aspergillus tamarii
keratitis. Ocular injury was known to be a predisposing factor. Topical natamycin and econazole treatment and subsequent systemic ketoconazole treatment proved effective. The isolate was identified by morphological characteristics and sequence analysis as
A. tamarii
, a member of
Aspergillus
section
Flavi
not hitherto reported from keratomycosis.
Seroepidemiology of Human Bocavirus in Hokkaido Prefecture, Japan
Authors: Endo Rika , Ishiguro Nobuhisa , Kikuta Hideaki , Teramoto Shinobu , Shirkoohi Reza , Ma Xiaoming , Ebihara Takashi , Ishiko Hiroaki , Ariga Tadashi 
Published: August 2007

ABSTRACT

A new human virus, provisionally named human bocavirus (HBoV), was discovered by Swedish researchers in 2005. A new immunofluorescence assay using
Trichoplusia ni
insect cells infected with a recombinant baculovirus expressing the VP1 protein of HBoV was developed, and the levels of immunoglobulin G antibody to the VP1 protein of HBoV in serum samples were measured. The overall seroprevalence rate of antibodies against the VP1 protein of HBoV in a Japanese population aged from 0 months to 41 years was 71.1% (145 of 204). The seropositive rate was lowest in the age group of 6 to 8 months and gradually increased with age. All of the children had been exposed to HBoV by the age of 6 years. A rise in titers of antibody against the VP1 protein of HBoV during the convalescent phase was observed for four patients with lower respiratory tract infections, and HBoV DNA was detected in nasopharyngeal swab and serum samples from all four patients. These results suggest that HBoV is a ubiquitous virus acquired early in life and that HBoV might play a role in the course of lower respiratory tract infections.
Strategic Approach To Produce Low-Cost, Efficient, and Stable Competitive Internal Controls for Detection of RNA Viruses by Use of Reverse Transcription-PCR
Authors: Villanova Gabriela V. , Gardiol Daniela , Taborda Miguel A. , Reggiardo Virginia , Tanno Hugo , Rivadeneira Emilia D. , Perez Germán R. , Giri Adriana A. 
Published: August 2007

ABSTRACT

Molecular diagnostics based on reverse transcription (RT)-PCR are routinely complicated by the lack of stable internal controls, leading to falsely negative results. We describe a strategy to produce a stable competitive internal control (CIC) based on a Qβ phage derivative (recombinant Qβ [rQβ]) bearing primers KY78 and KY80, which are widely used in the detection of hepatitis C virus (HCV). rQβ was RNase resistant and stable at 4°C for 452 days in SM medium (0.1 M NaCl, 8 mM MgSO
4
·7H
2
O, 50 mM Tris HCl [pH 7.5], 2% gelatin) and for 125 days after lyophilization and reconstitution. rQβ performance as a CIC was evaluated. rQβ was added to HCV-positive samples, followed by RNA extraction and a CIC-HCV RT-PCR assay. This method combines RT-PCR, liquid hybridization with nonradioactive probes, and enzyme immunoanalysis. No influence of the CIC on qualitative HCV detection was observed independently of viral load, and results had high concordance with those of commercial kits. In conclusion, we describe a versatile, low-cost alternative strategy to armored RNA technology that can be adapted for detection or real-time applications of any RNA target. Moreover, the CIC reported here is an essential reagent for HCV screening in blood banks in resource-limited settings.
Astrovirus Increases Epithelial Barrier Permeability Independently of Viral Replication
Authors: Moser Lindsey A. , Carter Michael , Schultz-Cherry Stacey 
Published: August 2007

ABSTRACT
Astrovirus infection in a variety of species results in an age-dependent diarrhea; however, the means by which astroviruses cause diarrhea remain unknown. Studies of astrovirus-infected humans and turkeys have demonstrated few histological changes and little inflammation during infection, suggesting that intestinal damage or an overzealous immune response is not the primary mediator of astrovirus diarrhea. An alternative contributor to diarrhea is increased intestinal barrier permeability. Here, we demonstrate that astrovirus increases barrier permeability in a Caco-2 cell culture model system following apical infection. Increased permeability correlated with disruption of the tight-junction protein occludin and decreased the number of actin stress fibers in the absence of cell death. Additionally, permeability was increased when monolayers were treated with UV-inactivated virus or purified recombinant human astrovirus serotype 1 capsid in the form of virus-like particles. Together, these results demonstrate that astrovirus-induced permeability occurs independently of viral replication and is modulated by the capsid protein, a property apparently unique to astroviruses. Based on these data, we propose that the capsid contributes to diarrhea in vivo.
Early Antibodies Specific for the Neutralizing Epitope on the Receptor Binding Subunit of the Lymphocytic Choriomeningitis Virus Glycoprotein Fail To Neutralize the Virus
Authors: Eschli Bruno , Zellweger Raphaël M. , Wepf Alexander , Lang Karl S. , Quirin Katharina , Weber Jacqueline , Zinkernagel Rolf M. , Hengartner Hans 
Published: August 2007

ABSTRACTLymphocytic choriomeningitis virus (LCMV) is a murine arenavirus whose glycoprotein consists of a transmembrane subunit (GP-2) and a receptor-binding subunit (GP-1). LCMV-neutralizing antibodies (nAbs) are directed against a single site on GP-1 and occur 1 month after the infection of cytotoxic-T-lymphocyte (CTL) deficient mice. In wild-type mice, however, CTLs control early infection, and weak nAb titers emerge very late (after 70 to 150 days) if at all. Production of recombinant GP-1 in native conformation enabled us to study the emergence of GP-1-binding antibodies directed against the neutralizing epitope. By combining binding and neutralization assays, we correlated the development of binding antibodies versus nAbs in wild-type and CTL-deficient mice after infection with different LCMV doses. We found that wild-type mice developed GP-1-specific antibodies already by day 8 after exposure to high but not low doses, demonstrating that naive GP-1-specific B cells were infrequent. Furthermore, the induced antibodies bound to the neutralizing GP-1 epitope but failed to neutralize the virus and therefore were of low affinity. In CTL-deficient mice, where massive viremia quickly levels initial differences in viral load, low and high doses induced low-affinity non-neutralizing GP-1-binding antibodies with kinetics similar to high-dose-infected wild-type mice. Only in CTL-deficient mice, however, the GP-1-specific antibodies developed into nAbs within 1 month. We conclude that LCMV uses a dual strategy to evade nAb responses in wild-type mice. First, LCMV exploits a “hole” in the murine B-cell repertoire, which provides only a small and narrow initial pool of low-affinity GP-1-specific B cells. Second, affinity maturation of the available low-affinity non-neutralizing antibodies is impaired.
Mechanisms of Late Restriction Induced by an Endogenous Retrovirus
Authors: Arnaud Frederick , Murcia Pablo R. , Palmarini Massimo 
Published: August 2007

ABSTRACT
The host has developed during evolution a variety of “restriction factors” to fight retroviral infections. We investigated the mechanisms of a unique viral block acting at late stages of the retrovirus replication cycle. The sheep genome is colonized by several copies of endogenous retroviruses, known as enJSRVs, which are highly related to the oncogenic jaagsiekte sheep retrovirus (JSRV). enJS56A1, one of the enJSRV proviruses, can act as a restriction factor by blocking viral particles release of the exogenous JSRV. We show that in the absence of enJS56A1 expression, the JSRV Gag (the retroviral internal structural polyprotein) targets initially the pericentriolar region, in a dynein and microtubule-dependent fashion, and then colocalizes with the recycling endosomes. Indeed, by inhibiting the endocytosis and trafficking of recycling endosomes we hampered JSRV exit from the cell. Using a variety of approaches, we show that enJS56A1 and JSRV Gag interact soon after synthesis and before pericentriolar/recycling endosome targeting of the latter. The transdominant enJS56A1 induces intracellular Gag accumulation in microaggregates that colocalize with the aggresome marker GFP-250 but develop into bona fide aggresomes only when the proteasomal machinery is inhibited. The data argue that dominant-negative proteins can modify the overall structure of Gag multimers/viral particles hampering the interaction of the latter with the cellular trafficking machinery.
Cyclodextrins Inhibit Replication of Scrapie Prion Protein in Cell Culture
Authors: Prior Marguerite , Lehmann Sylvain , Sy Man-Sun , Molloy Brendan , McMahon Hilary E. M. 
Published: August 2007

ABSTRACTPrion diseases are fatal neurodegenerative disorders that are caused by the conversion of a normal host-encoded protein, PrPC, to an abnormal, disease-causing form, PrPSc. This paper reports that cyclodextrins have the ability to reduce the pathogenic isoform of the prion protein PrPScto undetectable levels in scrapie-infected neuroblastoma cells. Beta-cyclodextrin removed PrPScfrom the cells at a concentration of 500 μM following 2 weeks of treatment. Structure activity studies revealed that antiprion activity was dependent on the size of the cyclodextrin. The half-maximal inhibitory concentration (IC50) for beta-cyclodextrin was 75 μM, whereas α-cyclodextrin, which possessed less antiprion activity, had an IC50of 750 μM. This report presents cyclodextrins as a new class of antiprion compound. For decades, the pharmaceutical industry has successfully used cyclodextrins for their complex-forming ability; this ability is due to the structural orientation of the glucopyranose units, which generate a hydrophobic cavity that can facilitate the encapsulation of hydrophobic moieties. Consequently, cyclodextrins could be ideal candidates for the treatment of prion diseases.