bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microwave Assisted Facile One-Pot Synthesis of 188Re-Complex Using a Tetrahydroborate Exchange Resin. A Bifunctional Chelating Agent for Radiopharmaceuticals
Authors: Park Sang Hyun , Gwon Hui Jeong , Park Kyung Bae 
Published: September 2004

Abstract
A facile one-pot synthesis of 188Re-complex as a bifunctional chelating agent for the preparation of therapeutic radiopharmaceuticals was accomplished with good labeling yields and radiochemical purity by using a tetrahydroborate exchange resin as a reducing agent for a disulfide ligand as well as the [188Re]perrhenate ion under microwave irradiation.
Delocalization of Positive and Negative Charge Carriers on Oligo- and Poly-fluorenes Studied by Low-Temperature Matrix Isolation Technique
Authors: Koizumi Yoshiko , Seki Shu , Acharya Anjali , Saeki Akinori , Tagawa Seiichi 
Published: September 2004

Abstract
Oligofluorenes with well-defined chain length (n = 1–5) have been synthesized by step-by-step Suzuki coupling reaction as the basis sets of conjugated segments in polyfluorenes. Cation and anion radicals of oligofluorenes (n &gt; 2) showed intense and clear three infrared absorptions attributed to transitions between SOMO state delocalized over fluorene moieties and valence (HOMOs) or conduction states (LUMOs) in the backbone. The transition energies of the IR band decreased linearly from 1.2 to 0.55 eV in the range of unit number while 1-D exciton transition energies showed apparent saturation at n &gt; 5. This implied that delocalization degree of excess electrons or holes along fluorene chains would saturate at larger number of units than that of neutral excitons.
Sexually Transmitted Diseases Among American Youth: Incidence and Prevalence Estimates, 2000
Authors: Weinstock Hillard , Berman Stuart , Cates Willard 
Published: September 2004

CONTEXT In the United States, young people aged 15–24 represent 25% of the sexually experienced population. However, the incidence and prevalence of sexually transmitted diseases (STDs) among this age‐group are unknown.METHODS Data from a variety of sources were used to estimate the incidence and prevalence of STDs among 15–24‐year‐olds in the United States in 2000. The quality and reliability of the estimates were categorized as good, fair or poor, depending on the quality of the data source.RESULTS Approximately 18.9 million new cases of STD occurred in 2000, of which 9.1 million (48%) were among persons aged 15–24. Three STDs (human papillomavirus, trichomoniasis and chlamydia) accounted for 88% of all new cases of STD among 15–24‐year‐olds.CONCLUSIONS These estimates emphasize the toll that STDs have on American youth. More representative data are needed to help monitor efforts at lowering the burden of these infections.
The Estimated Direct Medical Cost of Sexually Transmitted Diseases Among American Youth, 2000
Authors: Chesson Harrell W. , Blandford John M. , Gift Thomas L. , Tao Guoyu , Irwin Kathleen L. 
Published: September 2004

CONTEXT: Each year, millions of U.S. youth acquire sexually transmitted diseases (STDs). Estimates of the economic burden of STDs can help to quantify the impact of STDs on the nation's youth and on the payers of the cost of their medical care.METHODS: We synthesized the existing literature on STD costs to estimate the lifetime medical cost per case of eight major STDs–HIV, human papillomavirus (HPV), genital herpes simplex virus type 2, hepatitis B, chlamydia, gonorrhea, trichomoniasis and syphilis. We then estimated the total burden of disease by multiplying these cost‐per‐case estimates by the approximate number of new cases of STDs acquired by youth aged 15–24.RESULTS: The total estimated burden of the nine million new cases of these STDs that occurred among 15–24‐yearolds in 2000 was $6.5 billion (in year 2000 dollars). Viral STDs accounted for 94% of the total burden ($6.2 billion), and nonviral STDs accounted for 6% of the total burden ($0.4 billion). HIV and HPV were by far the most costly STDs in terms of total estimated direct medical costs, accounting for 90% of the total burden ($5.9 billion).CONCLUSIONS: The large number of infections acquired by persons aged 15–24 and the high cost per case of viral STDs, particularly HIV, create a substantial economic burden.
Adolescent Clinic Visits for Contraception: Support from Mothers, Male Partners and Friends
Authors: Harper Cynthia , Callegari Lisa , Raine Tina , Blum Maya , Darney Philip 
Published: September 2004

CONTEXT: To increase effective contraceptive use among adolescents at high risk of pregnancy, it is important to understand what factors influence them to visit a clinic for contraception, including support from their mothers, male partners and friends.METHODS: Data from a prospective cohort study of 399 teenage clinic attendees using the pill, the implant or condoms were collected through a questionnaire at baseline and at a one‐year follow‐up interview. Data were analyzed using multivariate regression analysis to show differences in social support for adolescents' clinic visit at baseline and method continuation at one year.RESULTS: Almost all teenagers (96%) reported that their mother, a male partner or a friend was aware of their clinic visit for contraception; of these, 92–96% also said that their mother or a male partner was supportive. Teenagers who chose the pill or implant were more likely than condom users to report that their mother and male partner were aware and that their mother was supportive of their contraceptive clinic visit. Implant users were significantly more likely than those who chose the pill or condom to continue using their chosen method for one year. Teenagers who took part in high‐risk behaviors were more likely than others to involve a friend but not their mother or a male partner in their contraceptive decision‐making.CONCLUSIONS: Pregnancy prevention programs and counseling protocols that integrate supportive networks for teenagers into contraceptive services may help adolescents to use effective methods.
Market Structure and Audit Fees: A Local Analysis*
Authors: BANDYOPADHYAY SATI P. , KAO JENNIFER L. 
Published: September 2004

AbstractThis study conducts a local analysis of the relation between market structure and audit fees. The research question of interest to us is how audit fees are determined by each practicing local office, after taking into account the auditor's own position in a local market and the influence exerted by his or her clients. Appealing to the economic theories of monopoly and monopsony power, we hypothesize a positive audit fee‐concentration relation, and a negative audit fee‐client influence relation. Results indicate that auditor market concentration is positively associated with the non‐Big 6 audit fees but is unrelated to the Big 6 audit fees. Evidence is mixed concerning the client influence hypothesis. When this construct is proxied by the number of rival auditors operating within a geographic area centered on the municipality, the prediction of negative audit fee‐client influence relation is strongly supported for both groups of auditors. Results are much weaker using measures developed based on the relative importance of a municipal client to its auditor's audit portfolio. The issues addressed in this study are important at a time when the Canadian municipal sector is undergoing major changes because of municipal amalgamation, altering the underlying market structure for audit services and the bargaining position of a municipality vis‐Ã‐vis its auditor. More broadly speaking, our analysis implies that when assessing an auditor's report for signs of client pressure, the professional oversight bodies and regulatory authorities need to consider the relative, rather than the absolute, bargaining position of the client in question.
Equilibrium Earnings Management, Incentive Contracts, and Accounting Standards*
Authors: LIANG PIERRE JINGHONG 
Published: September 2004

AbstractIn this paper, we model earnings management as a consequence of the interaction among self‐interested economic agents ‐ namely, the managers, the shareholders, and the regulators. In our model, a manager controls a stochastic production technology and makes periodic accounting reports about his or her performance; an owner chooses a compensation contract to induce desirable managerial inputs and reporting choices by the manager; and a regulatory body selects and enforces accounting standards to achieve certain social objectives. We show that various economic trade‐offs give rise to endogenous earnings management. Specifically, the owner may reduce agency costs by designing a compensation contract that tolerates some earnings management because such a contract allocates the compensation risk more efficiently. The earnings‐management activity produces accounting reports that deviate from those prescribed by accounting standards. Given such reports, the valuation of the firm may be nonlinear and s‐shaped, thereby recognizing the manager's reporting incentives. We also explore policy implications, noting that (1) the regulator may find enforcing a zero‐tolerance policy ‐ no earnings management allowed ‐ economically undesirable; and (2) when selecting the optimal accounting standard, valuation concerns may conflict with stewardship concerns. We conclude that earnings management is better understood in a strategic context that involves various economic trade‐offs.
Professionalization in Action: Accountants' Attempt at Building a Network of Support for the WebTrust Seal of Assurance*
Authors: GENDRON YVES , BARRETT MICHAEL 
Published: September 2004

AbstractThis paper examines the attempts by the North American accounting institutes to develop a new market in e‐commerce assurance based on their claims to professional expertise through the WebTrust project. Employing actor‐network theory in an in‐depth longitudinal field study, we investigate how WebTrust was originally developed and promoted as a seal of business‐to‐consumer assurance, which largely failed to generate support in the marketplace. Proponents were subsequently able to generate more interest in the eyes of managers of online organizations by reshaping WebTrust as a flexible set of principles and criteria for systems advice and business‐to‐business assurance. Our analysis suggests that attempts to expand the accounting profession's domain of expertise reflect a trial‐and‐error process where the outcome achieved may be far from the vision that motivated the institutes into undertaking the project in the first place. We further show that the initial network of support for such projects can be quite fragile and dynamic as various actors reposition themselves around the shifting meanings attributed to the project.
Decomposition of Fraud‐Risk Assessments and Auditors' Sensitivity to Fraud Cues*
Authors: WILKS T. JEFFREY , ZIMBELMAN MARK F. 
Published: September 2004

AbstractPractitioners and regulators are concerned that when auditors perceive management's attitude or character as indicative of low fraud risk, they are not sufficiently sensitive to high levels of incentive or opportunity risks in their overall fraud‐risk assessments. In this study, we examine whether a fraud‐triangle decomposition of fraud‐risk assessments (that is, separately assessing attitude, opportunity, and incentive risks prior to assessing overall fraud risk) increases auditors' sensitivity to opportunity and incentive cues when perceptions of management's attitude suggest low fraud risk. In an experiment with 52 practicing audit managers, we find that auditors who decompose fraud‐risk assessments are more sensitive to opportunity and incentive cues when making their overall assessments than auditors who simply make an overall fraud‐risk assessment. However, this increased sensitivity to opportunity and incentive cues appears to happen only when those cues suggest low fraud risk. When opportunity and incentive cues suggest high fraud risk, auditors are equally sensitive to those cues whether they use a decomposition or a holistic approach. We discuss and examine potential explanations for this finding.
JIT Adoption: The Effects of LIFO Reserves and Financial Reporting and Tax Incentives*
Authors: KINNEY MICHAEL R. , WEMPE WILLIAM F. 
Published: September 2004

AbstractUsing matched samples of JIT adopters and nonadopters, we examine the association of JIT adoption with firms' financial reporting and tax incentives, earnings‐management histories, and LIFO reserve levels. We find evidence that adoption decisions are influenced by the interaction of firms' LIFO reserves with their income smoothing, debt covenant, and tax incentives. We also find that adoption is less likely for firms historically engaging in high degrees of earnings management, particularly when such firms have no substantial LIFO reserves. Our study extends earlier research demonstrating a relation between inventory valuation method and year‐end inventory transactions, and documents a relation between earnings‐management incentives and a fundamental supply‐chain design choice.
A Nucleosome-Free dG-dC-Rich Sequence Element Promotes Constitutive Transcription of the Essential Yeast RIO1 Gene
Authors: Angermayr M. , Schwerdtfeger K. , Bandlow W. 
Published: September 2004

AbstractRIO1 is an essential gene that encodes a protein serine kinase and is transcribed constitutively at a very low level. Transcriptional activation of RIO1 dispenses with a canonical TATA box as well as with classical transactivators or specific DNA-binding factors. Instead, a dG-dC-rich sequence element, that is located 40 to 48 bp upstream the single site of mRNA initiation, is essential and presumably constitutes the basal promoter. In addition, we demonstrate here that this promoter element comprises a nucleosomefree gap which is centered at the dG-dC tract and flanked by two positioned nucleosomes. This element is both, necessary and sufficient, for basal transcription initiation at the RIO1 promoter and, thus, constitutes a novel type of core promoter element.
Molecular Recognition between Azotobacter vinelandii Rhodanese and a Sulfur Acceptor Protein
Authors: Cereda A. , Forlani F. , Iametti S. , Bernhardt R. , Ferranti P. , Picariello G. , Pagani S. , Bonomi F. 
Published: September 2004

Abstract
The occurrence of rhodanese-like proteins in the major
evolutionary phyla, together with the observed
abundance of these proteins also within the same
genome, suggests that their function cannot be limited
to cyanide scavenging. The aim of the present
study was to investigate whether Azotobacter vinelandii
RhdA, an enzyme possessing unique biochemical
and structural features with respect to other
members of rhodanese homology superfamily, could
recognize a suitable protein as a potential acceptor of
the sulfane sulfur held on its catalytic Cys residue.
Both the potential sulfur-delivery RhdA-S and the sulfur-
deprived RhdA were found to interact with either
holo- or apo-adrenodoxin, the 'substrate' protein
used in this work. Interaction of RhdA-S with apoadrenodoxin
led to mobilization of RhdA-S sulfane
sulfur. Under appropriate conditions, the sulfur released
from RhdA-S was productively used for 2Fe
2S cluster reconstitution to yield holo-adrenodoxin
from apo-adrenodoxin in the absence of any other
sulfur source. A comparison of the reactivity of RhdA-S
with protein and non-protein thiols allowed also
some insights into the accessibility of the sulfane sulfur
carried by RhdA.
Modulation of the Activation of Extracellular Signal-Regulated Kinase (ERK) and the Production of Inflammatory Mediators by ADP-Ribosylation Inhibitors
Authors: Page C. Le , Wietzerbin J. 
Published: September 2004

AbstractADP-ribosylation is involved in nuclear factor κB (NF-κB)-dependent gene expression induced by lipopolysaccharide in murine macrophages. Here we have investigated the mechanism by which ADP-ribosylation inhibitors block signaling pathways induced in macrophages. In RAW264.7 macrophages the inducers of NF-κB activate the production of reactive oxygen species and three mitogenactivated protein kinases (MAPK), the extracellular signal regulated kinase (ERK), the c-jun N-terminal kinase/stress-activated protein kinase (JNK), and p38. We demonstrate that ADP-ribosylation inhibitors specifically inhibit ERK MAPK activation and reduce the release of inflammatory mediators such as tumor necrosis factor α (TNF-α), IL-6 and nitrite.
Aza-Peptide Epoxides: Potent and Selective Inhibitors of Schistosoma mansoni and Pig Kidney Legumains (Asparaginyl Endopeptidases)
Authors: James K. E. , Götz M. G. , Caffrey C. R. , Hansell E. , Carter W. , Barrett A. J. , McKerrow J. H. , Powers J. C. 
Published: September 2004

Abstract
Aza-peptide epoxides are a new class of irreversible
cysteine protease inhibitors. Derivatives containing a
P1 aza-asparagine residue are specific for Schistosoma
mansoni and pig kidney legumains, which are clan
CD cysteine proteases. The inhibitors have secondorder
rate constants of up to 104 M-1s -1 with pig kidney
legumain and IC50 values as low as 45 nM with S.
mansoni legumain. The most potent epoxides contain
an ester moiety with S,S stereochemistry attached to
the epoxide. Interestingly, amide and amino acid derivatives
of the epoxysuccinate moiety were not inhibitors
of legumain, while disubstituted amide derivatives
are quite potent. The inhibitors have little or no
inhibitory activity with other proteases such as caspases,
chymotrypsin, papain, cathepsin B, granzyme
B, and various aspartyl proteases.
How Variability in OSB Mechanical Properties Affects Biological Durability Testing
Authors: Curling S. F. , Winandy J. E. , Carll C. , Micales J. A. , A. Tenwolde A. 
Published: September 2004

Summary
Loss in bending strength of wood has been shown to be a more sensitive measure of decay than is
weight loss. Using modulus of rupture as the decay criterion is problematic for oriented strandboard
(OSB) because of variation in mechanical properties due to particle orientation and size.
Moreover, the small specimen size required for such tests increases the variance in mechanical
properties. This study compared the variance in bending strength of ASTM D1037 standard-sized
specimens and small specimens from two samples of commercial OSB. The small specimens were
found to have a significantly higher level of variance in bending strength than the standard-sized
specimens. A simple method of sorting the specimens based on strand orientation on the tensile
surface significantly reduced the level of variance measured. The effects of differing levels of variance
on the size, design and limitations of the experimental study are presented.
Microfibril Angles Inside and Outside Crossfields of Norway Spruce Tracheids
Authors: Lichtenegger H. C. , Müller M. , Wimmer R. , Fratzl P. 
Published: September 2004

Summary
The major part of the wood cell wall consists of parallel-aligned cellulose fibrils. Locally, pits connecting
adjacent cell walls disturb the fibril arrangement. The local fibril orientation around these
mechanically weak points is crucial for the mechanical stability of the cell. In some softwood
species like spruce, the pit apertures at junctions of tracheids and cross-running ray parenchyma
cells are elongated and slit-like. The pit orientation has often been assumed to directly reflect the
fibril orientation. In this paper we use X-ray microdiffraction to determine the local microfibril angle
(tilt angle versus the cell axis, MFA) in single tracheid walls of Norway spruce in the vicinity of
pit apertures. The results from microdiffraction are compared with the pit orientation observed
under the light microscope.Whereas a good correlation was found in thick-walled latewood cells
from the stem and compression wood, large discrepancies occurred for thin-walled earlywood
cells. A simple mechanical model that could explain the different situation in earlywood and latewood
is presented.
Lignans and Lipophilic Extractives in Norway Spruce Knots and Stemwood
Authors: Willför S. , Hemming J. , Reunanen M. , Eckerman C. , Holmbom B. 
Published: September 2004

Summary
The hydrophilic and lipophilic extractives in the heartwood of knots from 7 Norway spruce trees
were analysed by GC, GC-MS and HPSEC. The knots contained extremely large amounts of lignans,
6–24% (w/w), with hydroxymatairesinol comprising 65–85% of the lignans. Even the knots
of the young trees contained 4–8% (w/w) of lignans. The variation in the amount of lignans was
large among knots, both within a single tree and between trees. In addition to the lignans, knots
also contained 2–6% (w/w) of a complex mixture of lignan-like compounds with 3, 4 and even up
to 6 phenyl propane units, here called oligolignans. The amounts of lignans in the knots were similar
in the radial direction from the pith into the outer branch, but decreased dramatically outwards
in the branch, almost disappearing after 10–20 cm. The ratio of the 2 epimers of hydroxymatairesinol
differed between different knots and even within the knot. A new spruce lignan, nortrachelogenin,
or its enantiomer, wikstromol, was detected in knots from trees in northern Finland
as opposed to samples from southern Finland. The amount of lipophilic extractives was small compared
to the amount of hydrophilic extractives in the knots. Five of the dead knots contained more
resin acids and free diterpenyl alcohols than ordinary stemwood. In the other knots, the amount of
lipophilic extractives was on the same level as stem heartwood. The stem sapwood contained larger
amounts of esterified fatty acids than the knots.
Reactions of Lignin with Peroxymonophosphoric Acid: The Degradation of Lignin Model Compounds
Authors: Zhu T. , Kadla J. F. , Chang H.-m. , Jameel H. 
Published: September 2004

Summary
Peroxymonophosphoric acid (Pp) has been shown to be an excellent delignification chemical for
kraft pulps. However, the reaction mechanism of Pp with lignin has not been elucidated. Therefore,
the reactions of Pp with non-phenolic lignin model compounds have been investigated at 70
and 90°C and compared to those of peroxymonosulfuric acid (Px). Pp and Px appear to follow
similar reaction pathways, however, the reaction kinetics are significantly different. Both Pp and
Px react with 1,2-Dimethoxy-4-methyl-benzene as electrophiles, with aromatic hydroxylation being
the main initial reaction. For 1-(3,4-Dimethoxy-phenyl)-ethanone, both Px and Pp react via the
Baeyer-Villiger reaction, in which the initial step is nucleophilic attack by the peracid.The reaction
with 1-(3,4-Dimethoxy-phenyl)-ethanol occurs primarily via carbocation formation followed by
subsequent reactions with the peracid. Changes in pH dramatically affect the reaction rates of Pp
with all the model compounds investigated, whereas with the exception of the Baeyer-Villiger reaction,
changes in pH did not affect the Px reactions. Below pH 2, Pp is a better electrophile than
Px, but above pH 2, Px is better. In addition, while Px remains reactive, Pp is not reactive at pH
above 7 for the model compounds investigated.
New Method for Quantitative Preparation of Lignin- Carbohydrate Complex from Unbleached Softwood Kraft Pulp: Lignin-Polysaccharide Networks I
Authors: Lawoko M. , Henriksson G. , Gellerstedt G. 
Published: September 2004

Summary
A new method for the quantitative preparation of pulp representative lignin-carbohydrate complexes
(LCC) has been developed, in which LCC has been systematically prepared at quantitative
yield, fractionated and qualitatively determined. At least 90% of residual lignin in softwood kraft
pulp is proposed to be chemically bonded to carbohydrates. A major part of LCC (92%) in softwood
kraft pulp was observed between lignin, xylan and glucomannan, whereas a minor part (8%)
was linked to cellulose. Half of the hemicelullosic LCC is a lignin-glucomannan complex. The other
half is lignin-xylan complex and xylan-lignin-glucomannan complex. Thus, part of the residual
lignin in softwood kraft pulp crosslinks xylan and glucomannan. The proposed linkages are of covalent
type. At most 10% of the residual lignin is not bonded covalently to carbohydrates.