bluuebunny/crossref_metadata_2025 huggingface dataset:
Key regulatory molecules of cartilage destruction in rheumatoid arthritis: an in vitrostudy
Authors: Andreas Kristin , Lübke Carsten , Häupl Thomas , Dehne Tilo , Morawietz Lars , Ringe Jochen , Kaps Christian , Sittinger Michael
Published: February 2008

Background

Rheumatoid arthritis (RA) is a chronic, inflammatory and systemic autoimmune disease that leads to progressive cartilage destruction. Advances in the treatment of RA-related destruction of cartilage require profound insights into the molecular mechanisms involved in cartilage degradation. Until now, comprehensive data about the molecular RA-related dysfunction of chondrocytes have been limited. Hence, the objective of this study was to establish a standardized in vitro model to profile the key regulatory molecules of RA-related destruction of cartilage that are expressed by human chondrocytes.

Methods

Human chondrocytes were cultured three-dimensionally for 14 days in alginate beads and subsequently stimulated for 48 hours with supernatants from SV40 T-antigen immortalized human synovial fibroblasts (SF) derived from a normal donor (NDSF) and from a patient with RA (RASF), respectively. To identify RA-related factors released from SF, supernatants of RASF and NDSF were analyzed with antibody-based protein membrane arrays. Stimulated cartilage-like cultures were used for subsequent gene expression profiling with oligonucleotide microarrays. Affymetrix GeneChip Operating Software and Robust Multi-array Analysis (RMA) were used to identify differentially expressed genes. Expression of selected genes was verified by real-time RT-PCR.

Results

Antibody-based protein membrane arrays of synovial fibroblast supernatants identified RA-related soluble mediators (IL-6, CCL2, CXCL1–3, CXCL8) released from RASF. Genome-wide microarray analysis of RASF-stimulated chondrocytes disclosed a distinct expression profile related to cartilage destruction involving marker genes of inflammation (adenosine A2A receptor, cyclooxygenase-2), the NF-κB signaling pathway (toll-like receptor 2, spermine synthase, receptor-interacting serine-threonine kinase 2), cytokines/chemokines and receptors (CXCL1–3, CXCL8, CCL20, CXCR4, IL-1β, IL-6), cartilage degradation (matrix metalloproteinase (MMP)-10, MMP-12) and suppressed matrix synthesis (cartilage oligomeric matrix protein, chondroitin sulfate proteoglycan 2).

Conclusion

Differential transcriptome profiling of stimulated human chondrocytes revealed a disturbed catabolic–anabolic homeostasis of chondrocyte function and disclosed relevant pharmacological target genes of cartilage destruction. This study provides comprehensive insight into molecular regulatory processes induced in human chondrocytes during RA-related destruction of cartilage. The established model may serve as a human in vitro disease model of RA-related destruction of cartilage and may help to elucidate the molecular effects of anti-rheumatic drugs on human chondrocyte gene expression.
Common interleukin-6promoter variants associate with the more severe forms of distal interphalangeal osteoarthritis
Authors: Kämäräinen Olli-Pekka , Solovieva Svetlana , Vehmas Tapio , Luoma Katariina , Riihimäki Hilkka , Ala-Kokko Leena , Männikkö Minna , Leino-Arjas Päivi
Published: February 2008

Introduction

The objective of this study was to investigate the relationship of the IL-6 promoter variants G-597A, G-572C and G-174C (rs1800797, rs1800796 and rs1800795, respectively), which have been shown to affect both the transcription and secretion of IL-6, to symptomatic distal interphalangeal (DIP) osteoarthritis (OA).

Methods

A total of 535 women aged 45 to 63 years were included. Radiographs of both hands were taken and each DIP joint was evaluated (grade 0 to 4) for the presence of OA. Information on symptoms (pain, tenderness) in each joint was collected by using a self-administered questionnaire. Symptomatic DIP OA was defined by the presence of both radiographic findings of grade 2 or more and symptoms in at least two DIP joints, and symmetrical DIP OA by the presence of radiographic findings of grade 2 or more in at least one symmetrical pair of DIP joints. Common polymorphic loci in the IL-6 gene were amplified and the promoter haplotypes were reconstructed from genotype data with the PHASE program. Logistic regression analysis was used to examine the association between the IL-6 genotypes/diplotypes and the DIP OA outcome.

Results

The G alleles of two promoter single nucleotide polymorphisms (SNPs) G-597A and G-174C were more common among the subjects with symptomatic DIP OA than among those with no disease (P = 0.020 and 0.024, corrected for multiple testing). In addition, the carriage of at least one G allele in these positions increased the risk of disease (P = 0.006 and P = 0.008, respectively). Carrying a haplotype with the G allele in all three promoter SNPs increased the risk of symptomatic DIP OA more than fourfold (odds ratio (OR) 4.45, P = 0.001). Carriage of the G-G diplotype indicated an increased risk of both symmetrical DIP OA (OR 1.52, 95% confidence interval 1.01 to 2.28) and symptomatic DIP OA (OR 3.67, 95% confidence interval 1.50 to 9.00).

Conclusion

The present study showed that the presence of G alleles at common IL-6 polymorphic promoter loci was associated with the more severe DIP OA outcomes, symmetrical and symptomatic.
Automated eukaryotic gene structure annotation using EVidenceModeler and the Program to Assemble Spliced Alignments
Authors: Haas Brian J , Salzberg Steven L , Zhu Wei , Pertea Mihaela , Allen Jonathan E , Orvis Joshua , White Owen , Buell C Robin , Wortman Jennifer R
Published: February 2008

EVidenceModeler (EVM) is presented as an automated eukaryotic gene structure annotation tool that reports eukaryotic gene structures as a weighted consensus of all available evidence. EVM, when combined with the Program to Assemble Spliced Alignments (PASA), yields a comprehensive, configurable annotation system that predicts protein-coding genes and alternatively spliced isoforms. Our experiments on both rice and human genome sequences demonstrate that EVM produces automated gene structure annotation approaching the quality of manual curation.
Adverse Adipose Phenotype and Hyperinsulinemia in Gravid Mice Deficient in Placental Growth Factor
Authors: Hemmeryckx Bianca , van Bree Rita , Van Hoef Berthe , Vercruysse Lisbeth , Lijnen H. Roger , Verhaeghe Johan
Published: February 2008

Pregnancy-induced metabolic changes are regulated by signals from an expanded adipose organ. Placental growth factor (PlGF), acting through vascular endothelial growth factor receptor-1, may be among those signals. There is a steep rise in circulating PlGF during normal pregnancy, which is repressed in gravidas who develop preeclampsia. PlGF-deficiency in mice impairs adipose vascularization and development. Here we studied young-adult PlGF-deficient (PlGF−/−) and wild-type mice on a high-fat diet in the nongravid state and at embryonic day (E) 13.5 or E18.5 of gestation. Litter size and weight were normal, but E18.5 placentas were smaller in PlGF−/− pregnancies. PlGF−/− mice showed altered intraadipose dynamics, with the following: 1) less blood vessels and fewer brown, uncoupling protein (UCP)-1-positive, adipocytes in white sc and perigonadal fat compartments and 2) white adipocyte hypertrophy. The mRNA expression of β3-adrenergic receptors, peroxisome proliferator-activated receptor-γ coactivator-1α, and UCP-1 was decreased accordingly. Moreover, PlGF−/− mice showed hyperinsulinemia. Pregnancy-associated changes were largely comparable in PlGF−/− and wild-type dams. They included expanded sc fat compartments and adipocyte hypertrophy, whereas adipose expression of key angiogenesis/adipogenesis (vascular endothelial growth factor receptor-1, peroxisome proliferator-activated receptor-γ2) and thermogenesis (β3-adrenergic receptors, peroxisome proliferator-activated receptor-γ coactivator-1α, and UCP-1) genes was down-regulated; circulating insulin levels gradually increased during pregnancy. In conclusion, reduced adipose vascularization in PlGF−/− mice impairs adaptive thermogenesis in favor of energy storage, thereby promoting insulin resistance and hyperinsulinemia. Pregnancy adds to these changes by PlGF-independent mechanisms. Disturbed intraadipose dynamics is a novel mechanism to explain metabolic changes in late pregnancy in general and preeclamptic pregnancy in particular.
The role of educational track in adolescents' school burnout: A longitudinal study
Authors: Salmela‐Aro Katariina , Kiuru Noona , Nurmi Jari‐Erik
Published: February 2008

BackgroundTransition from comprehensive school to later educational tracks is challenging for many adolescents. The present three‐wave longitudinal study conducted in Finland considers this issue from the perspective of school burnout.

AimsThe study investigated the extent to which school‐related burnout (exhaustion, cynicism, and feelings of inadequacy) changes during the transition from comprehensive school to an academic or vocational track.

SampleThe participants of the present study were 658 ninth graders, who filled in questionnaires twice during their final term of comprehensive school and once after the transition to post‐comprehensive schooling.

MethodsThe participants filled in the school burnout inventory and supplied background information on gender and academic achievement. The data have analysed by latent growth curve modelling.

ResultsThe results showed that adolescents on an academic track experienced more exhaustion at school than those on a vocational track. Moreover, among adolescents on an academic track both the level of cynicism and inadequacy at school increased across time. In turn, among adolescents on a vocational track inadequacy at school decreased across time while cynicism increased before the school transition and decreased thereafter. Girls experienced more overall school burnout than boys, and adolescents whose academic achievement was lower experienced a higher level of burnout than adolescents who did better at school.

ConclusionsThe results support the stage‐environment fit theory according to which the nature of the environments in academic and vocational education are more important than the transitionper sefor changes in how adolescents think and feel about school (seeEccles & Midgley, 1989).
Some practical constraints on Cognitive Ethology: Striking the balance between a theoretical approach and a practical methodology
Authors: Crundall David , Underwood Geoffrey
Published: February 2008

This is a Commentary on Kingstone et al. (2008).
Bias in Sensitivity and Specificity Caused by Data-Driven Selection of Optimal Cutoff Values: Mechanisms, Magnitude, and Solutions
Authors: Leeflang Mariska M G , Moons Karel G M , Reitsma Johannes B , Zwinderman Aielko H
Published: February 2008

Background: Optimal cutoff values for tests results involving continuous variables are often derived in a data-driven way. This approach, however, may lead to overly optimistic measures of diagnostic accuracy. We evaluated the magnitude of the bias in sensitivity and specificity associated with data-driven selection of cutoff values and examined potential solutions to reduce this bias.

Methods: Different sample sizes, distributions, and prevalences were used in a simulation study. We compared data-driven estimates of accuracy based on the Youden index with the true values and calculated the median bias. Three alternative approaches (assuming a specific distribution, leave-one-out, smoothed ROC curve) were examined for their ability to reduce this bias.

Results: The magnitude of bias caused by data-driven optimization of cutoff values was inversely related to sample size. If the true values for sensitivity and specificity are both 84%, the estimates in studies with a sample size of 40 will be approximately 90%. If the sample size increases to 200, the estimates will be 86%. The distribution of the test results had little impact on the amount of bias when sample size was held constant. More robust methods of optimizing cutoff values were less prone to bias, but the performance deteriorated if the underlying assumptions were not met.

Conclusions: Data-driven selection of the optimal cutoff value can lead to overly optimistic estimates of sensitivity and specificity, especially in small studies. Alternative methods can reduce this bias, but finding robust estimates for cutoff values and accuracy requires considerable sample sizes.
Pervious Concrete Mixture Proportions for Improved Freeze-Thaw Durability
Authors: Kevern J. T. , Schaefer V. R. , Wang K. , Suleiman M. T.
Published: February 2008

Recent stormwater management regulations from the Environmental Protection Agency (EPA) and greater emphasis on sustainable development has increased interest in pervious pavement as a method for reducing stormwater runoff and improving stormwater quality. Pervious concrete is one of several pervious pavement systems that can be used to reduce stormwater runoff and treat stormwater on site. Pervious concrete systems have been used and are being proposed for all parts of the United States, including northern climates where severe freezing and thawing can occur. The purpose of the research is to develop pervious concrete mixtures that have sufficient porosity for stormwater infiltration along with desirable porosity, strength, and freeze-thaw durability. In this research, concrete mixtures were developed with single-sized river gravel aggregate (4.75 mm) and constant binder contents, together with high range water reducer. River sand was used as a replacement for up to 7 % coarse aggregate. Two different types of polypropylene fibers (a shorter fibrillated variable-length and a longer fibrillated single-length) were incorporated at several addition rates from 0 to 0.1 % by volume of concrete. The engineering properties of the aggregate were evaluated along with the porosity, permeability, strength, and freeze-thaw durability of selected concrete mixtures. The results indicate that the use of sand and fibers provided beneficial effects on pervious concrete properties, including increased strength, maintained or improved permeability, and enhanced freeze-thaw resistance.
Chukchi Gold: American Enterprise and Russian Xenophobia in the Northeastern Siberia Company
Authors: Owen Thomas C.
Published: February 2008

During the gold rush in Nome, Alaska, neither Russians nor Americans found significant quantities of gold on the Chukchi Peninsula, across the Bering Strait from the Seward Peninsula. Despite its failure, the documents of the Northeastern Siberian Company (1902–1914) and the memoirs of its managers and employees illuminate important contrasts between the political and cultural perspectives of its founders in St. Petersburg and those of its agents in Seattle. The Russian criticisms of American managers of the company also place the Soviet government's antipathy to American capitalism in historical context. Despite many differences between the tsarist and Marxist-Leninist ideologies, the hostile stereotypes of Americans expressed by tsarist officials and Russian capitalists in St. Petersburg persisted into the Soviet and post-Soviet periods.
Why Southern Gospel Music Matters
Authors: Harrison Douglas
Published: February 2008

Long overlooked by scholars of culture and religion, southern (white) gospel music occupies a special place within evangelicalism. The dynamic interaction of lyrics, music, and religious experience in southern gospel music comprises a cultural discourse evangelicals use, not to diminish experience in this world as is commonly argued in southern gospel studies, but to understand better Protestant theological doctrines in, and to make useable meaning out of, the vicissitudes of conservative Christian life. This approach treats southern gospel as a network of interconnected rhetorics and signifying practices that serve a multitude of public and private needs among its performers and fans—needs that are not otherwise met in evangelical culture. Particularly, southern gospel music allows those who participate in it to explore a broader and deeper range of psychospiritual feelings and experiences. The study of southern gospel reveals the importance of private conflicts and tensions in defining the contours of conservative Protestant religious living, individually and collectively. For the millions of evangelicals today who turn regularly and eagerly to southern gospel, their identity as a covenanted elect emerges from within the struggle to manage and resolve spiritual disquietude through the experience of white gospel music.
Tumor Necrosis Factor-α Inhibition of Skeletal Muscle Regeneration Is Mediated by a Caspase-Dependent Stem Cell Response
Authors: Moresi Viviana , Pristerà Alessandro , Scicchitano Bianca M. , Molinaro Mario , Teodori Laura , Sassoon David , Adamo Sergio , Coletti Dario
Published: February 2008

Skeletal muscle is susceptible to injury following trauma, neurological dysfunction, and genetic diseases. Skeletal muscle homeostasis is maintained by a pronounced regenerative capacity, which includes the recruitment of stem cells. Chronic exposure to tumor necrosis factor-α (TNF) triggers a muscle wasting reminiscent of cachexia. To better understand the effects of TNF upon muscle homeostasis and stem cells, we exposed injured muscle to TNF at specific time points during regeneration. TNF exposure delayed the appearance of regenerating fibers, without exacerbating fiber death following the initial trauma. We observed modest cellular caspase activation during regeneration, which was markedly increased in response to TNF exposure concomitant with an inhibition in regeneration. Caspase activation did not lead to apoptosis and did not involve caspase-3. Inhibition of caspase activity improved muscle regeneration in either the absence or the presence of TNF, revealing a nonapoptotic role for this pathway in the myogenic program. Caspase activity was localized to the interstitial cells, which also express Sca-1, CD34, and PW1. Perturbation of PW1 activity blocked caspase activation and improved regeneration. The restricted localization of Sca-1+, CD34+, PW1+ cells to a subset of interstitial cells with caspase activity reveals a critical regulatory role for this population during myogenesis, which may directly contribute to resident muscle stem cells or indirectly regulate stem cells through cell-cell interactions.

Disclosure of potential conflicts of interest is found at the end of this article.
Sustained Endothelial Progenitor Cell Dysfunction After Chronic Hypoxia-Induced Pulmonary Hypertension
Authors: Marsboom Glenn , Pokreisz Peter , Gheysens Olivier , Vermeersch Pieter , Gillijns Hilde , Pellens Marijke , Liu Xiaoshun , Collen Désiré , Janssens Stefan
Published: February 2008

Circulating endothelial progenitor cells (EPCs) contribute to neovascularization of ischemic tissues and repair of injured endothelium. The role of bone marrow-derived progenitor cells in hypoxia-induced pulmonary vascular remodeling and their tissue-engineering potential in pulmonary hypertension (PH) remain largely unknown. We studied endogenous mobilization and homing of EPCs in green fluorescent protein bone marrow chimeric mice exposed to chronic hypoxia, a common hallmark of PH. Despite increased peripheral mobilization, as shown by flow cytometry and EPC culture, bone marrow-derived endothelial cell recruitment in remodeling lung vessels was limited. Moreover, transfer of vascular endothelial growth factor receptor-2+/Sca-1+/CXCR-4+-cultured early-outgrowth EPCs failed to reverse PH, suggesting hypoxia-induced functional impairment of transferred EPCs. Chronic hypoxia decreased migration to stromal cell-derived factor-1α, adhesion to fibronectin, incorporation into a vascular network, and nitric oxide production (−41%, −29%, −30%, and −32%, respectively, vs. normoxic EPCs; p < .05 for all). The dysfunctional phenotype of hypoxic EPCs significantly impaired their neovascularization capacity in chronic hind limb ischemia, contrary to normoxic EPCs cultured in identical conditions. Mechanisms contributing to EPC dysfunction include reduced integrin αv and β1 expression, decreased mitochondrial membrane potential, and enhanced senescence. Novel insights from chronic hypoxia-induced EPC dysfunction may provide important cues for improved future cell repair strategies.

Disclosure of potential conflicts of interest is found at the end of this article.
Hedgehog Signaling Alters Adipocyte Maturation of Human Mesenchymal Stem Cells
Authors: Fontaine Coralie , Cousin Wendy , Plaisant Magali , Dani Christian , Peraldi Pascal
Published: February 2008

Human stem cells are powerful tools by which to investigate molecular mechanisms of cell growth and differentiation under normal and pathological conditions. Hedgehog signaling, the dysregulation of which causes several pathologies, such as congenital defects and cancer, is involved in several cell differentiation processes and interferes with adipocyte differentiation of rodent cells. The present study was aimed at investigating the effect of Hedgehog pathway modulation on adipocyte phenotype using different sources of human mesenchymal cells, such as bone marrow stromal cells and human multipotent adipose-derived stem cells. We bring evidence that Hedgehog signaling decreases during human adipocyte differentiation. Inhibition of this pathway is not sufficient to trigger adipogenesis, but activation of Hedgehog pathway alters adipocyte morphology as well as insulin sensitivity. Analysis of glycerol-3-phosphate dehydrogenase activity and expression of adipocyte marker genes indicate that activation of Hedgehog signaling by purmorphamine impairs adipogenesis. In sharp contrast to reports in rodent cells, the maturation process, but not the early steps of human mesenchymal stem cell differentiation, is affected by Hedgehog activation. Hedgehog interferes with adipocyte differentiation by targeting CCAAT enhancer-binding protein α and peroxisome proliferator-activated receptor (PPAR) γ2 expression, whereas PPARγ1 level remains unaffected. Although Hedgehog pathway stimulation does not modify the total number of adipocytes, adipogenesis appears dramatically impaired, with reduced lipid accumulation, a decrease in adipocyte-specific markers, and acquisition of an insulin-resistant phenotype. This study indicates that a decrease in Hedgehog signaling is necessary but not sufficient to trigger adipocyte differentiation and unveils a striking difference in the adipocyte differentiation process between rodent and human mesenchymal stem cells.

Disclosure of potential conflicts of interest is found at the end of this article.
Introduction
Authors: Bunn Paul A. , Thatcher Nick
Published: February 2008

Lung cancer is the most common cancer and a highly lethal disease, with improvements in survival rates being dependent on advances in early detection and improved systemic therapies applied to surgery and/or irradiation in early-stage disease. Non-small cell lung cancer (NSCLC) represents around 80% of all lung cancers, and unfortunately at diagnosis most patients have advanced unresectable disease with a very poor prognosis. Indeed, 30%–40% of patients treated with first-line therapy will subsequently be candidates for second-line treatment. Current U.S. Food and Drug Administration–approved second-line treatments are docetaxel (a taxane), pemetrexed (a folate antimetabolite), and erlotinib (an epidermal growth factor receptor [EGFR] tyrosine kinase inhibitor [TKI]). Gefitinib, another EGFR TKI, currently has only limited use in North America and is not available in Europe. These and other new molecular-target-specific agents may have the potential to maximize therapeutic benefit while minimizing toxicity to normal cells. Overexpression of EGFR is reported to occur in 40%–80% of NSCLC cases, and EGFR mutations are associated with a significantly higher response rate and longer duration of response following treatment with EGFR TKIs. Another option is antiangiogenesis: the growth and persistence of solid tumors and their metastases are angiogenesis dependent, and so antiangiogenic therapies have been developed, such as the use of TKIs that block the vascular endothelial growth factor receptor. In fact, many commonly used chemotherapeutic drugs have antiangiogenic activity. Ongoing studies are focusing on patient selection and targeted therapies, and there are many new agents undergoing clinical trials.
Local Control of Regional and Metastatic Lesions and Indication for Systemic Chemotherapy in Patients with Non-Small Cell Lung Cancer
Authors: Sekine Ikuo , Sumi Minako , Saijo Nagahiro
Published: February 2008

Systemic chemotherapy is the mainstay of treatment in patients with advanced non-small cell lung cancer. Local control of regional and metastatic lesions may be needed before systemic therapy can be started in patients with pleural effusions or bone or brain metastases. The indication for systemic chemotherapy depends on the symptoms and performance status of the patient. In addition, a risk assessment considering complications such as hemodynamic and respiratory compromise by effusions, pathological bone fractures, and neurologic deterioration caused by brain metastases is critical in selecting which patients should receive first-line systemic chemotherapy before local therapy, although predictive factors for these complications have not yet been established. Chemotherapy has been considered to have only a limited role in the treatment of patients with pleural effusions and brain and bone metastases, but recently developed anticancer agents have shown substantial antitumor effects in these types of patients with a good general condition.
The Effects of Decision Aid Design on the Information Search Strategies and Confirmation Bias of Tax Professionals
Authors: Wheeler Patrick R. , Arunachalam Vairam
Published: February 2008

We report the results of a study involving 142 tax professionals designed to investigate the effects of decision aid design on information search (i.e., tax research) and confirmation bias. Results indicate that the participants exhibited confirmation bias when conducting tax research for clients. That is, participants showed a tendency to preferentially select information in support of their earlier recommendations to the client, even when the recommendation disagreed with the client's subsequent tax position. Results also indicate that while some decision aid features can reduce confirmation bias during tax research, others do not and may even enhance this bias. Specifically, a justification requirement decision aid reduced confirmation bias in terms of both the number and perceived importance of selected confirmatory cases, whereas a factor evaluation checklist decision aid either increased the bias (i.e., increased the perceived importance of cases) or had no effect on the bias (i.e., no effect on the number of cases). We suggest several decision aid design features for reducing confirmation bias in tax research.
The Impact of Nonaudit Service Fee Levels on Investors' Perception of Auditor Independence
Authors: Davis Shawn M. , Hollie Dana
Published: February 2008

We extend Dopuch et al. (2003) by examining the effect of various fee ratios on investor perception of auditor independence and market behavior. Consistent with Dopuch et al. (2003), we find disclosure of nonaudit fees reduces the accuracy of investor perception of auditor independence. More importantly, we document that the proportionate level of nonaudit fees to total fees has a varying impact on investor perception of auditor independence and market behavior. In particular, there appears to be a nonlinear effect between investor perception of auditor independence and market behavior. In summary, when investors perceive auditor independence is impaired as a result of the level of nonaudit fees, more asset pricing inefficiencies occur in these experimental markets.
An Empirical Examination of a Three-Component Model of Professional Commitment among Public Accountants
Authors: Smith David , Hall Matthew
Published: February 2008

Professional commitment (PC) refers to the attachments that individuals form to their profession. While prior accounting literature has examined only one dimension of PC, research outside accounting has established that there are three distinct dimensions to PC (Hall et al. 2005). In this paper we test the validity of Meyer et al.'s (1993) three-component model of PC among a sample of public accountants. Given that the majority of studies of accountants' PC have used the Professional Commitment Questionnaire (PCQ), we also assess whether the PCQ is a measure of a specific dimension of PC, affective PC. The results of our confirmatory factor analyses and tests of reliability and validity provide support for three separate dimensions of public accountants' PC. Our tests also indicate that the PCQ scale is a measure of affective PC. The implications of our results on interpreting prior research and for considering future research on accountants' PC are presented.
Accounting for Derivatives and Hedging Activities: Comparison of Cash Flow versus Fair Value Hedge Accounting
Authors: Smith Pamela A. , Kohlbeck Mark J.
Published: February 2008

Warfield Company is considering hedging the risk associated with (1) an available-for-sale (AFS) security portfolio and (2) an anticipated purchase of oil. Warfield's Board of Directors has limited experience in this area and has requested that you summarize the accounting and reporting implications if these items are hedged. The hedged risk in these two transactions can be either the risk associated with the cash flow or the risk associated with changes in the fair value. The two risks are discussed in separate parts of the case.
Cooperative Learning in a Passive Learning Environment: A Replication and Extension
Authors: Hwang Nen-Chen Richard , Lui Gladie , Wu Tong Marian Yew Jen
Published: February 2008

This study replicates Hwang et al. (2005) with a different cohort of accounting majors. This study also extends Hwang et al.'s (2005) article by exploring the effectiveness of employing cooperative learning pedagogy to enhance students' learning outcomes at both the application level and analysis level of knowledge (Bloom 1956). Different from the original paper, this study evaluates participants' learning outcomes using cases with supporting calculations, instead of multiple-choice questions. Overall, this study finds that cooperative learning is a more effective pedagogy than traditional lecture for students who were raised and educated in a passive learning environment. Limitations and possible directions for future research are also discussed.
Sachiko Corporation: A Case in International Financial Statement Analysis
Authors: Gujarathi Mahendra R.
Published: February 2008

Sachiko is a comprehensive case on financial statement analysis within an international context. Upon reviewing the financial statements and relevant footnotes of Sachiko Corporation, a Japanese company, and U.S.-based Radiance Inc., you are required to restate the two companies' financials to evaluate whether the revised ratios are consistent with each company's strategy and business environment and, subsequently, to recommend the better investment prospect. The case provides a forum for you to examine the role of environmental differences (cultural, institutional, business, and financial reporting) in interpreting the risk and profitability ratios in an international context.
The Timeless Way of Building REA Enterprise Systems
Authors: Geerts Guido L. , Wang Harry Jiannan
Published: February 2008

In a continuously changing business environment, the need for enterprise systems that are more adaptable has been recognized by many. Several solutions are being suggested to improve the adaptability of enterprise systems, including service-oriented architectures, model-driven architectures, and reflective architectures. In this paper, we propose a timeless way of building enterprise systems that employs a reflective architecture with integrated Resource-Event-Agent (REA) enterprise ontology specifications. We show how the explicit recording of enterprise schema descriptions results in enterprise systems with increased adaptability. In addition, we demonstrate how explicitly recorded ontological specifications can further increase application reusability. We validate our research with a prototype system.
Performance and Perceptions in an Online, Distributed Environment: Effects of Collaborative versus Individual Activities
Authors: Ray Amy W. , Prosch Marilyn M. , Roberts Douglas F.
Published: February 2008

This study compares participant perceptions of and performance in individual and collaborative activities using an emergent online learning tool with a variety of sophisticated features, including the ability to move dynamically between individual and collaborative participation. Study findings indicate that when engaging in online learning activities, participating in collaborative activities leads to more favorable attitudes toward the experience as well as higher levels of perceived learning than engaging in individual activities. Further, the average quality of responses on collaborative activities is higher than average responses on individual activities. Implications for future use of online, distributed learning tools are discussed along with implications for related future research.
Artificial Neural Network Assistant (ANNA) for Continuous Auditing and Monitoring of Financial Data
Authors: Koskivaara Eija , Back Barbro
Published: February 2008

This paper presents the development and applications of ANNA—Artificial Neural Network Assistant (ANNA) for continuous auditing and monitoring of financial data. The prototype presented here provides automatically six types of expectation values for account values and compares them to the actual values. In this study, ANNA is used for analyzing monthly account values. ANNA's predictions or account expectations are based on function approximation (modeling) capability from the previous years' monthly account values. ANNA uses a flexible one-step-ahead prediction model. The results are illustrated both by a graph on the computer screen and in the tables. The evaluation of results show that artificial neural networks technology is competitive compared to other methods used in this study.
Running Training After Stroke: A Single-Subject Report
Authors: Miller Ellen W , Combs Stephanie A , Fish Caryn , Bense Brooke , Owens Amanda , Burch Andrea
Published: February 2008

Background and Purpose

Although many people who have had a stroke are primarily interested in learning to walk, some are able to focus on a return to recreational and sporting activities. This study was carried out to investigate the feasibility and effectiveness of the use of intensive task-oriented training in the body-weight–support/treadmill environment to improve running for a subject after stroke.

Subject

The subject was a 38-year-old man who had a stroke 2.5 years previously.

Methods

A single-subject design with baseline, intervention, immediate postintervention, and 6-month postintervention phases was conducted. Dependent variables included 25-m sprint time, single-leg balance, running step width, running step length ratio, Stroke Impact Scale, 6-minute walk test, and lower-extremity strength (force-generating capacity).

Results

At the 6-month postintervention phase, sprint speed, left single-leg balance, and step width changed significantly from the baseline phase. Step length ratio trended toward less symmetry but more consistency, and muscle strength improved more than 20% in 6 of 8 muscle groups in the involved lower extremity and 4 of 8 muscle groups in the uninvolved lower extremity.

Discussion and Conclusion

Intensive task-specific training was feasible and effective for retraining running ability in the study subject. He returned to recreational running, which provided him with a greatly improved outlook and a better quality of life.
The effect of the expansion of the clonal grass Calamagrostis epigejos on the species turnover of a semi‐arid grassland
Authors: Somodi Imelda , Virágh Klára , Podani János
Published: February 2008

Question: How does the dominance of Calamagrostis epigejos influence species turnover of a grassland?

Location: Loess grassland at the foothills of Bükk Mountains, Hungary (47°54’ N., 20°35’ E).

Methods: Presence/absence of vascular plants and different performance attributes of C. epigejos were recorded in a plot‐subplot system between 2002 and 2005. Appearance and disappearance rates of grassland species were calculated for pairs of consecutive years. 1. Mean appearance and disappearance rates were compared in grassland plots dominated by C. epigejos and in plots free from this species, based on Monte Carlo randomization. 2. Mean appearance rates were assessed for categories of C. epigejos performance and their confidence intervals were calculated via Monte Carlo randomization. For two performance variables (percentage cover and shoot number) analyses were performed at two spatial scales.

Results: 1. C. epigejos.‐dominated plots differed from unaffected ones by significantly lower appearance rates. 2. Change in appearance rates was best explained by differences in percentage cover of C. epigejos. Coarse‐scale C. epigejos performance had a closer correspondence with appearance rate change than fine‐scale performance. Low level C. epigejos performance enhanced appearance rate compared to intact stands, while high level performance decreased it, regardless of the choice of performance measure.

Conclusions: C. epigejos lowers species number by hindering reappearance of species of the original grassland. This is best explained by the increased shading effect at the coarse scale. The marked non‐linear initial enhancement in appearance rate, however, can also be taken as an early sign of future species loss.
The suppression ofDendroctonus frontalisand subsequent wildfire have an impact on forest stand dynamics
Authors: Coleman T.W. , Meeker James R. , Clarke Stephen R. , Rieske L.K.
Published: February 2008

Question:Interacting disturbance effects fromDendroctonus frontalisoutbreaks and wildfire are thought to maintainPinusspp. composition in the southeastern U. S. Our objective was to assess forest composition, structure, and succession following the interaction of two frequently occurring disturbance events in southernPinusspp. forests: cut‐and‐leave suppression, a commonly used means for managingD. frontalisoutbreaks, and wildfire.

Location:Western Gulf Coastal Plain, Louisiana, USA.

Method:Pinus taedastands with cut‐and‐leave suppression and subsequent wildfire were compared to stands undisturbed byD. frontalisbut with the same wildfire events twenty years afterPinusspp. mortality. The woody plant community was assessed in three different size classes and used to predict future forest types with the Forest Vegetation Simulator (50 years).

Results:P. taedais the most abundant (> 50%) species of saw‐ and poletimber‐sizes following cut‐and‐leave suppression with wildfire and in stands only with fire. Using canonical correspondence analysis, vegetation assemblages were primarily explained by slope position and elevation (7.6% variation explained). Fire intensity and stand age also accounted for variance in the ordination (4.4% and 3.1%, respectively). Dominant and co‐dominantP. taedaforest types were predicted by the model to be the most abundant forest types in each disturbance regime. In addition, new regeneration represents high hazard for future mortality fromD. frontalis.

Conclusion:Our study demonstrates that cut‐and‐leave suppression with additional wildfire disturbance maintainsP. taedacomposition, and does not alter forest composition differently from stands receiving only wildfire. As a result, predictedPinusspp. basal area under both disturbances is great enough to facilitate future bark beetle disturbance.
Cloning of Small RNA Molecules
Authors: Pfeffer Sébastien , Lagos‐Quintana Mariana , Tuschl Thomas
Published: February 2008

Small RNAs that are derived from dsRNA precursors act as guide RNAs during sequence‐specific epigenetic regulation of eukaryotic gene expression. These small regulatory RNAs are between 20 and 30 nucleotides in length, and fall into one or more of the following categories: small interfering RNAs (siRNAs), microRNAs (miRNAs), and heterochromatic siRNAs (hsiRNAs). Procedures to record the profile of small RNAs expressed in cultured cells or tissues are described. The small RNAs are directionally cloned after isolation from total RNA. The methods rely on T4 RNA ligase‐based joining of adapter oligonucleotides to the 3′ and 5′ termini of the pool of small RNAs. The ligation products are reverse transcribed and PCR‐amplified. It is recommended to directionally concatamerize the relatively short PCR products before cloning in order to increase the number of RNA sequences obtained per clone.
RNAi in Transgenic Plants
Authors: Yin Yanhai , Chory Joanne , Baulcombe David
Published: February 2008

RNA silencing in plants is a rapid and facile approach for assignment of gene function and virus resistance. It allows selective RNA degradation through a mechanism that is given specificity by short interfering RNAs. The RNA silencer sequences are normally delivered as transgenes or a part of virus‐vectors. This unit provides Basic Protocols for transgene and virus induced silencing. It also includes a Basic Protocol for protein overexpression using viral proteins that suppress silencing.
Investigation of Dynamic Intra‐ and Intermolecular Processes within a Tether‐Length Dependent Series of Group 4 Bimetallic Initiators for Stereomodulated Degenerative Transfer Living Ziegler–Natta Propene Polymerization
Authors: Zhang Wei , Sita Lawrence R.
Published: February 2008

The series of bimetallic complexes, [(η5‐C5Me5)Zr(Me)2]2 [N(t‐Bu)C(Me)N(CH2)nNC(Me)N(t‐Bu)] 3 (n=8), 4 (n=6), and 5 (n=4) were prepared in high yield through a simple, one‐pot synthesis involving 2 equiv. of in situ generated (η5‐C5Me5)Zr(Me)3 and the corresponding bis‐carbodiimide, (t‐Bu)NCN(CH2)nNCN(t‐Bu). Compounds 3–5 were found to be highly isoselective for the living Ziegler–Natta polymerization of propene upon 100% activation using 2 equiv. of the borate co‐initiator, [PhNHMe2] [B(C6F5)4] (2), with the degree of stereoselectivity decreasing slightly as the two metal centers are brought closer together [cf., 3 (σ=0.92)>4 (σ=0.91)>5 (σ=0.89)]. Under conditions of sub‐stoichiometric activation by 2, all three bimetallic initiators, 3–5, were found to engage in degenerative transfer living Ziegler–Natta polymerization involving rapid and reversible methyl group transfer between active, (cationic) and dormant, (neutral) methyl, polymeryl zirconium centers. Under these conditions, the frequency of mr triad stereoerror incorporation into the polypropene (PP) microstructure decreases as the two metal centers are brought closer together as a result of increasing barriers for metal‐centered epimerization within the neutral metal site due to correspondingly greater non‐bonded steric interactions vis‐à‐vis mononuclear 1.
Novel Palladium‐on‐Carbon/Diphenyl Sulfide Complex for Chemoselective Hydrogenation: Preparation, Characterization, and Application
Authors: Mori Akinori , Mizusaki Tomoteru , Kawase Masami , Maegawa Tomohiro , Monguchi Yasunari , Takao Shinobu , Takagi Yukio , Sajiki Hironao
Published: February 2008

A diphenyl sulfide immobilized on palladium‐on‐carbon system, Pd/C[Ph2S], was developed to achieve the highly chemoselective hydrogenation of alkenes, acetylenes, azides, and nitro groups in the presence of aromatic ketones, halides, benzyl esters, and N‐Cbz protective groups. Instrumental analyses of the heterogeneous catalyst demonstrated that diphenyl sulfide was embedded on Pd/C via coordination of its sulfur atom to palladium metal or physical interaction with graphite layers of the activated carbon. The catalyst could be recovered and reused at least five times without any significant loss of the reactivity.
Cooling of spherical particles in a vertical airlift conveyor
Authors: Davies C. E. , Davies R. Y. G.
Published: February 2008

The airlift conveyor modelled here is of a type used in industry to move a particulate feedstock from ground level to an elevated position for gravity feeding to storage or further processing options. It consists of a feed leg and a vertical riser which terminates in a de‐entrainment device where the particles are removed from the conveying gas. Typically the conveying gas enters the riser from a vertical or horizontal feed pipe, and blows the particles off the face of an aerated bed in the horizontal leg of the feeder. The flow rate of the solids is controlled by aeration gas which partially fluidises the material in the feed leg. In this article, we consider the cooling of spherical particles admitted to a conveyor, for a variety of processing conditions. The riser in the model conveyor was 8 m high, the initial particle temperature was 40 °C and the temperature of the conveying air was 20 °C in all calculations. The conveying velocities used were, 12, 15 and 18 m s−1, and the particle sizes were 0.5, 1.0 and 1.5 mm. The particle flow rate was 1 tonne/h. The calculation methodology was to find analytically the slip velocity profile of a single particle over the length of the riser, and then to estimate heat transfer rates numerically using a Microsoft Office Excel spreadsheet. Temperature profiles show that for all conditions examined, over 70–80% of heat transfer takes place in the first half of the riser. Copyright © 2008 Curtin University of Technology and John Wiley & Sons, Ltd.
Synthesis and characterization of nylon 6/clay nanocomposites prepared by ultrasonication and in situ polymerization
Authors: McAdam C. P. , Hudson N. E. , Liggat J. J. , Pethrick R. A.
Published: February 2008

Nylon 6 nanocomposites were prepared by the in situ polymerization of ε‐caprolactam with ultrasonically dispersed organically modified montmorillonite clay (Cloisite 30B®). Dispersions of the clay platelets with concentrations in the range 1–5 wt % in the monomer were characterized using rheological measurements. All mixtures exhibited shear‐thinning, signifying that the clay particles were dispersed as platelets and forming a “house of cards” structure. Samples with Cloisite concentrations above 2 wt % showed a drop in viscosity between the initial shearing and repeated shearing, indicative of shearing breaking down the initial “house of cards” structures formed on sonication. DMTA measurements of the samples showed an increase in the β‐relaxation temperature with increasing clay concentration. The bending modulus, at temperatures below Tg, showed an increase with increasing clay concentration up to 4 wt %. X‐ray diffraction measurements showed that all nylon 6/Cloisite 30B samples were exfoliated apart from the 5 wt %, which showed that some intercalated material was present. The nylon crystallized into the α‐crystalline phase, which is the most thermodynamically stable form. Preference for this form may be a consequence of the long time associated with the postcondensation step in the synthesis or the influence of the platelets on the nucleation step of the crystal growth. DSC measurements showed a retardation of the crystallization rate of nanocomposite samples when compared with that of pure nylon 6, due to the exfoliated clay platelets hindering chain movement. This behavior is different from that observed for the melt‐mixed nylon 6/clay nanocomposites, which show an enhancement in the crystallization rate. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008