bluuebunny/crossref_metadata_2025 huggingface dataset:
The Persistence, Forecasting, and Valuation Implications of the Tax Change Component of Earnings
Authors: Schmidt Andrew P.
Published: March 2008

I examine whether earnings generated by changes in effective tax rates (the tax change component) persist and aid in forecasting future earnings. In addition, this study investigates to what extent investors incorporate the forecasting implications of the tax change component of earnings into stock prices. I find that there is a positive, significant association between the tax change component of earnings and future earnings. I use the interim reporting requirements of APB No. 28 (APB 1973) and FASB Interpretation No. 18 (FASB 1977) to further decompose the tax change component into an initial and a revised portion based on the first quarter estimate of the annual effective tax rates (ETR). I find that the initial tax change component is more persistent for future earnings than the revised tax change component. These results are consistent with my hypotheses that the initial and revised tax change components have differential persistence and forecasting implications, and dispute the broad notion advanced by prior literature that ETR-related earnings changes are transitory. Results from market tests indicate that the market underweights the forecasting implications of the tax change component and the mispricing appears to be driven by the transitory nature of the revised tax change component.
The Implications of Accounting Distortions and Growth for Accruals and Profitability
Authors: Richardson Scott A. , Sloan Richard G. , Soliman Mark T. , Tuna I˙rem
Published: March 2008

Following Sloan (1996), numerous studies document that the accrual component of earnings is less persistent than the cash flow component of earnings. Disagreement exists, however, as to the explanation for this result. One stream of literature follows Sloan's lead in arguing that this result is attributable to accounting distortions (Xie 2001; Dechow and Dichev 2002; Richardson et al. 2005). A second stream of literature argues that this result is attributable to a more general growth effect and that growth-related factors such as diminishing returns to new investment explain the lower persistence of accruals (e.g., Fairfield et al. 2003a; Cooper et al. 2005). We provide new evidence indicating that temporary accounting distortions are a significant contributing factor to the lower persistence of the accrual component of earnings. Our evidence indicates that the lower persistence of accruals extends to accruals that are unrelated to sales growth and that extreme accruals are systematically associated with alleged cases of earnings manipulation.
Uncertainty, Legal Liability, and Incentive Contracts
Authors: Evans John H. , Kim Kyonghee , Nagarajan Nandu J.
Published: March 2008

To address agents' moral hazard over effort, incentive contracts impose risk on the agents. As performance measures become noisier, the conventional agency analysis predicts that principals will reduce the incentive weights assigned to such measures. However, prior empirical results (Prendergast 2002) frequently find the opposite, i.e., incentive weights are larger (agents bear more risk) in more uncertain environments. This paper provides new evidence on the association between the extent of uncertainty and the level of risk imposed on agents. In the context of contracts between managed care organizations and physicians, we examine the effect of task characteristics and the legal liability environment on the extent of risk that physicians bear. We derive the optimal weighting of multiple performance measures in a model of a physician's choice of revenue-generating and cost-control efforts. The model predicts that physicians who face less task uncertainty bear more cost risk in their contracts, as predicted by the conventional moral hazard model. Likewise, the model predicts that as the association between task uncertainty and legal liability uncertainty becomes stronger, physicians bear less cost risk in their contracts. Our empirical results generally support these predictions. We offer an explanation for why these results tend to be consistent with the conventional moral hazard analysis, contrary to empirical results in a number of previous studies.
Auditor-Provided Tax Services: The Effects of a Changing Regulatory Environment
Authors: Omer Thomas C. , Bedard Jean C. , Falsetta Diana
Published: March 2008

This study investigates auditor-provided tax services from 2000 to 2002, during which fees paid to auditors for nonaudit services (NAS) were disclosed, but separate disclosure of tax service fees was voluntary. We examine changes in the market for tax NAS in 2002, as Congress debated possible prohibition of these services. Using the Heckman MLE procedure to control for selection bias in tax fee disclosure, we find that a strong pre-2002 positive association between tax fees and higher than expected audit fees weakened significantly in 2002, suggesting that some companies paying high audit fees reduced or terminated auditor-provided tax services in 2002. Our findings also suggest that auditor-provided tax services were reduced among new or short-tenure clients. Controlling for tax complexity, we also find some evidence that early “returns” (i.e., tax rate reductions) to companies from auditorprovided tax services were reduced in 2002. Finally, results of our selection model imply that the decision to voluntarily disclose fees paid to the auditor for tax services is positively associated with tax complexity and auditor tenure, and negatively associated with the proportion of NAS fees to total fees. Overall, our findings imply significant change in auditor-provided tax services prior to 2003, when separate disclosure of auditor-provided tax service fees was mandated.
Accounting Quality and Firm-Level Capital Investment
Authors: Biddle Gary C. , Hilary Gilles
Published: March 2008

This study examines how accounting quality relates to firm-level capital investment efficiency. Our first hypothesis is that higher quality accounting enhances investment efficiency by reducing information asymmetry between managers and outside suppliers of capital. Our second hypothesis is that this effect should be stronger in economies where financing is largely provided through arm's-length transactions compared with countries where creditors supply more capital. Our results are consistent with these hypotheses both across and within countries. They are robust to alternative econometric specifications, different measures of accounting quality and investment-cash flow sensitivity, and numerous control variables.
Segment Profitability, Misvaluation, and Corporate Divestment
Authors: Chen Peter F. , Zhang Guochang
Published: March 2008

This paper develops a theoretical model to explain corporate divestment in the context of accounting-based valuation and provides empirical evidence to support the model's predictions. Building on Zhang's (2000) real-options-based equity value model, we develop a model to explain why firms with multiple business segments may have incentives in financial reporting to shift earnings from one segment to another to influence market valuation. Cross-segment earnings shifting, however, causes information asymmetry about segmental performance, which leads to market misvaluation. Divestment arises as a voluntary commitment by (some) firms to not engage in segmental earnings manipulation, with the aim of restoring valuation accuracy. Our theoretical analysis yields a number of testable implications. Consistent with our model's predictions, we find empirically that (1) divestment is preceded by an increased divergence in profitability between the divested and continuing segments of the divesting firm, (2) there are positive abnormal stock returns surrounding divestment announcements that are not dependent on increased expectations about future operating performance, (3) the magnitude of market revaluation increases with the profitability divergence between the divested and continuing segments, and (4) market revaluation is greater for more complex firms (in terms of having a larger number of segments and greater uncertainty facing investors).
GASB No. 34's Governmental Financial Reporting Model: Evidence on Its Information Relevance
Authors: Plummer Elizabeth , Hutchison Paul D. , Patton Terry K.
Published: March 2008

This study uses a sample of 530 Texas school districts to investigate the information relevance of governmental financial statements published under Governmental Accounting Standards Board Statement No. 34 (GASB No. 34). Specifically, we examine whether the new government-wide statements provide information relevant for assessing a government's default risk, and if this information is incremental to that provided by the governmental funds statements. GASB No. 34 requires governments to publish governmental funds statements prepared on a modified accrual basis, and government-wide statements prepared on an accrual basis. We find that GASB No. 34's Statement of Net Assets (similar to a corporation's balance sheet) provides information relevant for assessing default risk, and this information is incremental to that provided by the governmental funds statements. However, GASB No. 34's Statement of Activities (similar to a corporation's income statement) does not provide information relevant for assessing default risk. The accrual “earnings” measure is not more informative than the modified-accrual “earnings” measure. A government's modified accrual earnings measure can be thought of as a type of measure of changes in working capital. Therefore, our results are consistent with research on corporate entities that attributes the superiority of earnings over cash flows primarily to working capital accruals and not long-term accruals. For our sample of school districts, evidence suggests that total net assets from the government-wide Statement of Net Assets, along with a measure of modified-accrual “earnings” from the governmental funds statement, provide the best information for explaining default risk.
The Effect of Auditors' Use of a Reciprocity-Based Strategy on Auditor-Client Negotiations
Authors: Sanchez Maria H. , Agoglia Christopher P. , Hatfield Richard C.
Published: March 2008

Auditors face the challenging tasks of attesting that the financial statements are free from material misstatement while simultaneously fostering a functional working relationship with the client. As the financial statements may be considered, in part, a product of negotiations between the auditor and client management (Antle and Nalebuff 1991), the negotiation strategy employed by the auditor may be useful in effectively fulfilling both tasks. To investigate the effect of auditor strategy on the resolution of proposed audit adjustments in a post Sarbanes-Oxley environment, we conduct experiments that examine both the client and auditor sides of the negotiation. We investigate a strategy of “concession” that draws upon the societal rule of reciprocation, which makes the waiving of inconsequential audit differences transparent. Specifically, with a concession approach, the auditor brings to the attention of the client all the audit differences (both significant and inconsequential) discovered during the audit and, subsequently, waives the inconsequential items. In contrast, a strategy of “no-concession” of inconsequential items (in which the auditor discloses to the client only the significant audit differences that must be booked) renders the client unaware of the waived inconsequential differences. Results from the client experiments indicate that, relative to a no-concession approach, participants representing client management (controllers/CFOs) are more willing to post significant income-decreasing adjustments (both objective and subjective) when exposed to a concession approach in the course of negotiating the final contents of the audited financial statements. A concession approach also results in greater client satisfaction and retention. Consistent with these findings, results from the auditor experiment suggest that auditors also perceive that altering their approach toward greater disclosure of waived inconsequential audit differences can improve client satisfaction and retention.
The Effects of Sarbanes-Oxley on Auditing and Internal Control Strength
Authors: Patterson Evelyn R. , Smith J. Reed
Published: March 2008

We provide a theoretical investigation of the effects of the Sarbanes-Oxley Act of 2002 on auditing intensity and internal control strength. We propose a model of strategic auditing in which the auditor can use resources for both internal control tests and substantive tests, while the manager can choose the strength of internal controls and the amount of fraud.

We find that control tests are a valuable tool for the auditor when control strength is informative about the likelihood of fraud. We find that Sarbanes-Oxley has the desired effect of inducing stronger internal control systems and less fraud, but does not necessarily induce higher levels of control testing. Our model suggests that audit risk increases as a result of the Sarbanes-Oxley Act.
The Influence of Forecast Dispersion on the Incremental Explanatory Power of Earnings, Book Value, and Analyst Forecasts on Market Prices
Authors: Bryan Daniel M. , Tiras Samuel L.
Published: March 2008

This study investigates the influence of analyst forecast dispersion on Ohlson's (2001) proposed linear information dynamics where consensus analyst forecasts are suggested as a proxy for other information. Our results indicate that Ohlson's proposed valuation model is most descriptive of market pricing when forecast dispersion, and hence information asymmetry, is high. Our results also suggest that when analysts are confronted with high information asymmetry, they tend to focus less on accounting fundamentals and rely more on other nonaccounting information, thus decreasing the correlation between the explanatory power of analyst forecasts and that of earnings and book value.
Strategic Errors and Audit Quality: An Experimental Investigation
Authors: Fischbacher Urs , Stefani Ulrike
Published: March 2008

We report experimental results for a simple bimatrix game between a manager and an auditor. We investigate whether the quality of audited financial statements improves if the relative proportion of perfectly honest auditors increases. We find that the quality of audited reports is higher if computerized auditors who always perform a high audit effort are present. This result is in direct contrast to the Nash prediction for our game. The Quantal Response Equilibrium, which explicitly takes into account boundedly rational behavior, supports our experimental data. Our main findings depend neither on framing nor the payoff matrix we use.
Information Asymmetry, Diversification, and Cost of Capital
Authors: Hughes John S. , Liu Jing , Liu Jun
Published: March 2008

Recently, there has been considerable interest among accounting researchers in the relation between asymmetric information and cost of capital. A number of empirical studies document associations between risk premiums and proxies for asymmetric information such as earnings quality. However, the theoretical foundation for these studies has yet to be fully established. In this study, we consider the effects of private signals that are informative of both systematic factors and idiosyncratic shocks affecting asset payoffs in a competitive, noisy, rational expectations setting. Taking a large economy limit, we show that (1) risk premiums equal products of betas and factor risk premiums, irrespective of information asymmetries; (2) holding total information constant, greater information asymmetry leads to higher factor risk premiums and, thus, higher costs of capital; and (3) controlling for betas, there is no cross-sectional effect of information asymmetries on cost of capital. These results provide guidance in interpreting the findings of existing empirical work and suggest specifications helpful for future research.
Information Pursuit in Financial Statement Analysis: Effects of Choice, Effort, and Reconciliation
Authors: Nelson Mark W. , Tayler William B.
Published: March 2008

Prior research provides evidence that information affects financial statement users' judgments less when that information is provided in a less accessible format (e.g., information disclosed in a footnote or less prominent financial statement rather than being recognized on the income statement [Maines and McDaniel 2000]). We provide evidence that, conditional on users performing the analysis necessary to transform the financial statements to appear as if disclosed information had been recognized, that information may affect users' judgments more than it would have if it had been recognized initially. Our experiments are set in the context of constructive capitalization of operating leases. The first experiment manipulates three variables that we hypothesize will contribute to this effect: choice to use transformed financial statements, effort spent on the transformation process, and reconciliation of pre- and post-transformation numbers. We provide evidence that, in the constructive-capitalization setting we operationalize, information has a greater effect on judgments when effort was expended to obtain the information and the information is displayed in a reconciled format. The second experiment focuses on the effort effect and replicates it with additional controls. These results have implications for standard-setters who consider the relative benefits of recognition and disclosure, and for financial statement users who transform financial statements as part of their analyses.
Do Cross-Border Listing Firms Manage Earnings or Seize a Window of Opportunity?
Authors: Ndubizu Gordian A.
Published: March 2008

Firms raising new equity capital at cross-listing (IPO) and those crosslisting existing home-country public shares (non-IPO) benefit from earnings that are high when they cross-list on U.S. stock exchanges. IPO firms have greater benefits than non-IPO firms because they receive cash infusion at listing. I find that performance (ROA) and cash flows peak at cross-listing period for all cross-border firms. Using a matched-firm research design to control for industry and performance, the results suggest that both IPO and non-IPO firms time cross-listing when performance is peaking (seize a window of opportunity). Further tests investigate whether IPO and non-IPO firms differ in their incentives to engage in earnings management at the time of cross-listing. The results suggest that both appear to engage in the same level of earnings management at the time of cross-listing. This suggests that incentives to boost earnings to obtain higher cash infusion are not the main motivation for the earnings management observed. Other incentives, such as greater investor recognition could be a stronger motivation.
Profits versus Losses: Does Reporting an Accounting Loss Act as a Heuristic Trigger to Exercise the Abandonment Option and Divest Employees?
Authors: Pinnuck Matt , Lillis Anne M.
Published: March 2008

The binary classification of firms into profits or losses represents a powerful heuristic. The literature that has examined the impact on the firm of this earnings heuristic has focused on the earnings management actions of small profit firms. The impact of this earnings heuristic on the actions of firms reporting accounting losses and the decision-making effects the heuristic may have other than earnings management have not been examined. In this study we hypothesize that reporting an accounting loss acts as a heuristic trigger for firms to exercise the abandonment option and discard unproductive investments. The results are consistent with the hypothesis. We find that there is a sharp and economically significant discontinuity around zero in the level of investment in labor between small profit and small loss firms. The discontinuity is due to loss firms having a lower-than-expected level of investment in labor, given their economic fundamentals. Further tests show that this discontinuity is due to the exercise of the abandonment option. We find that firms switching from a profit to a loss cut labor to a greater extent than other firms with similar changes in earnings that do not pass the loss threshold. Taken together the results are consistent with the accounting loss heuristic acting as a major disciplinary or incentive altering event that resolves agency problems.
Corporate Governance, Audit Quality, and the Sarbanes-Oxley Act: Evidence from Internal Audit Outsourcing
Authors: Abbott Lawrence J. , Parker Susan , Peters Gary F. , Rama Dasaratha V.
Published: March 2008

This study extends current literature related to nonaudit services by investigating internal audit outsourcing to the external auditor. We posit that certain types of internal audit outsourcing (i.e., those which are nonroutine, and thus tend to be nonrecurring in nature) are unlikely to lead to economic bonding, while offering significant potential for improvements in audit coverage and scope when provided by the external auditor. Alternatively, outsourcing routine internal audit tasks is more likely to lead to economic bonding, as well as potentially threatening internal auditor independence. Our results are consistent with firms with independent, active, and expert audit committees being less likely to outsource routine internal auditing activities to the external auditor. However, the outsourcing of nonroutine internal audit activities such as special projects and EDP consulting are not negatively related to effective audit committees. Additionally, outsourcing of either type of internal audit activity to an outside service provider other than the external auditor is not related to effective audit committees. Collectively, we interpret these findings as supportive of an effective audit committee's ability to monitor the sourcing of the firm's total (i.e., internal and external) audit coverage, while simultaneously exhibiting concern for external auditor independence.
Cost Allocation for Capital Budgeting Decisions
Authors: Baldenius Tim , Dutta Sunil , Reichelstein Stefan
Published: March 2008

Investment decisions frequently require coordination across multiple divisions of a firm. This paper explores a class of capital budgeting mechanisms in which the divisions issue reports regarding the anticipated profitability of proposed projects. To hold the divisions accountable for their reports, the central office ties the project acceptance decision to a system of cost allocations comprised of depreciation and capital charges. If the proposed project concerns a common asset that benefits multiple divisions, then our analysis derives a sharing rule for dividing the asset among the users. Capital charges are based on a hurdle rate determined by the divisional reports. We find that this hurdle rate deviates from the firm's cost of capital in a manner that depends crucially on whether the coordination problem is one of implementing a common asset or choosing among multiple competing projects. We also find that more severe divisional agency problems will increase the hurdle rate for common assets, yet this is generally not true for competing projects.
Audit Team Brainstorming, Fraud Risk Identification, and Fraud Risk Assessment: Implications of SAS No. 99
Authors: Carpenter Tina D.
Published: March 2008

SAS No. 99 requires brainstorming sessions on each audit to help auditors detect fraud. This study investigates audit team brainstorming sessions and the resulting fraud judgments. The psychology literature provides mixed results on the benefits of brainstorming. Results from my experiment suggest that while the overall number of ideas is reduced, brainstorming audit teams generate more quality fraud ideas than individual auditors generate before the brainstorming session. Further, audit teams generate new quality fraud ideas during the brainstorming session. Results also suggest that audit teams' fraud risk assessments after the brainstorming session are significantly higher than those assessments given by individual auditors on the team prior to the brainstorming session, especially when fraud is present. These results should be informative to standard setters as they suggest that brainstorming audit teams' generation of new quality fraud ideas and their improved fraud risk assessments will likely enhance their ability to identify fraud.
When Security Analysts Talk, Who Listens?
Authors: Mikhail Michael B. , Walther Beverly R. , Willis Richard H.
Published: March 2008

Regulators' interest in analyst reports stems from the belief that small investors are unaware of the conflicts sell-side analysts face and may, as a consequence, be misled into making suboptimal investment decisions. We examine who trades on security analyst stock recommendations by extending prior research to focus on investor-specific responses to revisions. We find that both large and small traders react to analyst reports; however, large investors appear to trade more than small traders in response to the information conveyed by the analyst's recommendation and earnings forecast revision (proxied by the magnitudes of the recommendation change and the earnings forecast revision, respectively). We also find that small investors do not fully account for the effects of analysts' incentives on the credibility of analyst reports, as captured by the type of recommendation (i.e., upgrade versus downgrade or buy versus sell). In particular, small investors not only trade more than large investors following upgrade and buy recommendations, but also trade more following upgrade and buy recommendations than they do following downgrade and hold/sell recommendations. Furthermore, we observe that, on average, small traders are net purchasers following recommendation revisions regardless of the type of the recommendation; large traders tend to be net sellers following downgrades and sells. Consequently, large traders generate statistically positive returns from their trading, while small traders generate statistically negative returns from their trading. These findings are consistent with large investors being more sophisticated processors of information, and provide some support for regulators' concerns that analysts may more easily mislead small investors.
Internal Control Weakness and Cost of Equity: Evidence from SOX Section 404 Disclosures
Authors: Ogneva Maria , Subramanyam K. R. , Raghunandan K.
Published: March 2008

We examine the association between cost of equity and internal control weakness (ICW) for firms that filed first-time Section 404 reports with the SEC. Using several proxies, we find higher implied cost of equity associated with ICW firms than for a control sample of firms that disclosed no ICW. However, the higher cost of equity associated with ICW disappears after controlling for primitive firm characteristics and for analyst forecast bias. Overall, we find that, on average, ICWs are not directly associated with higher cost of equity.
Private Earnings Guidance and Its Implications for Disclosure Regulation
Authors: Wang Isabel Yanyan
Published: March 2008

This study investigates three related questions: (1) Why did some firms provide private earnings guidance to analysts before Regulation Fair Disclosure? (2) How did the exogenous shock of Regulation Fair Disclosure affect these firms' disclosure policies? (3) What are the economic consequences of this disclosure regulation? To address these questions, I develop a new measure of private earnings guidance.

Consistent with theory, I find that firms were more likely to provide private earnings guidance if they had higher proprietary information costs, and if their earnings were more predictive of other firms' earnings. Policymakers enacted Regulation Fair Disclosure to stop private earnings guidance, but they also intended for managers to replace private earnings guidance with public earnings guidance, thereby improving the information environment. However, I find that roughly half of the firms that I classify as relying more on private earnings guidance replace private earnings guidance with non-disclosure instead of public earnings guidance, and as a result, these firms suffer significant deterioration in their information environments. Consistent with theory, firms are more likely to replace private earnings guidance with nondisclosure if they have lower information asymmetry and higher proprietary information costs. On the other hand, firms that replace private earnings guidance with public earnings guidance, on average, prevent significant deterioration in their information environments. Evidence that firms respond to disclosure regulation as predicted by theory can help policymakers anticipate which firms' information environments are likely to be adversely affected by new disclosure regulations.
Do Effects of Client Preference on Accounting Professionals' Information Search and Subsequent Judgments Persist with High Practice Risk?
Authors: Kadous Kathryn , Magro Anne M. , Spilker Brian C.
Published: March 2008

Prior research indicates that audit and tax professionals' judgments are influenced by their client's preferences, both directly and indirectly (via information search). In an experiment with tax professionals as participants, we examine whether high practice risk (i.e., exposure to monetary and nonmonetary costs of making inappropriate recommendations) mitigates these effects. We find that, when facing a client with low practice risk, professionals' search is biased in a manner that leads judgments to be consistent with client preference; however, search is less biased when facing a client with high practice risk, and resulting judgments are less consistent with client preference. We also find that, after controlling for the impact of information search, professionals tend to adjust their recommendations away from the client-preferred position, regardless of practice risk. This study sheds light on the direct and indirect paths by which client preference and practice risk affect professionals' judgments.
The Contagion Effects of Accounting Restatements
Authors: Gleason Cristi A. , Jenkins Nicole Thorne , Johnson W. Bruce
Published: March 2008

We predict and find that accounting restatements that adversely affect shareholder wealth at the restating firm also induce share price declines among non-restating firms in the same industry. These share price declines are unrelated to changes in analysts' earnings forecasts, but instead seem to reflect investors' accounting quality concerns. Peer firms with high industry-adjusted accruals experience a more pronounced share price decline than do low-accrual firms. This accounting contagion effect is concentrated among revenue restatements by relatively large firms in the industry. We also find that investors impose a larger penalty on the stock prices of peer firms with high earnings and high accruals when peer and restating firms use the same external auditor. Our results are consistent with the notion that some accounting restatements cause investors to reassess the financial statement information previously released by non-restating firms.
Increased GABAergic Tone in the Ventromedial Hypothalamus Contributes to Suppression of Counterregulatory Reponses After Antecedent Hypoglycemia
Authors: Chan Owen , Cheng Haiying , Herzog Raimund , Czyzyk Daniel , Zhu Wanling , Wang Ajin , McCrimmon Rory J. , Seashore Margretta R. , Sherwin Robert S.
Published: March 2008

OBJECTIVE—We have previously demonstrated that modulation of γ-aminobutyric acid (GABA) inhibitory tone in the ventromedial hypothalamus (VMH), an important glucose-sensing region in the brain, modulates the magnitude of glucagon and sympathoadrenal responses to hypoglycemia. In the current study, we examined whether increased VMH GABAergic tone may contribute to suppression of counterregulatory responses after recurrent hypoglycemia.

RESEARCH DESIGN AND METHODS—To test this hypothesis, we quantified expression of the GABA synthetic enzyme, glutamic acid decarboxylase (GAD), in the VMH of control and recurrently hypoglycemic rats. Subsequently, we used microdialysis and microinjection techniques to assess changes in VMH GABA levels and the effects of GABAA receptor blockade on counterregulatory responses to a standardized hypoglycemic stimulus.

RESULTS—Quantitative RT-PCR and immunoblots in recurrently hypoglycemic animals revealed that GAD65 mRNA and protein were increased 33 and 580%, respectively. Basal VMH GABA concentrations were more than threefold higher in recurrently hypoglycemic animals. Furthermore, whereas VMH GABA levels decreased in both control and recurrently hypoglycemic animals with the onset of hypoglycemia, the fall was not significant in recurrently hypoglycemic rats. During hypoglycemia, recurrently hypoglycemic rats exhibited a 49–63% reduction in glucagon and epinephrine release. These changes were reversed by delivery of a GABAA receptor antagonist to the VMH.

CONCLUSIONS—Our data suggest that recurrent hypoglycemia increases GABAergic inhibitory tone in the VMH and that this, in turn, suppresses glucagon and sympathoadrenal responses to subsequent bouts of acute hypoglycemia. Thus, hypoglycemia-associated autonomic failure may be due in part to a relative excess of the inhibitory neurotransmitter, GABA, within the VMH.
Tree-Ring Chronology as a Source of Information on Susceptibility of Sitka Spruce to Climatic Conditions of Pomerania (Northern Poland)
Authors: Feliksik Edward , Wilczyński Sławomir
Published: March 2008

This paper presents results concerning climatic conditions affecting diameter growth of Sitka spruce introduced to Baltic Pomerania (Sławno Forest District). A relatively high homogeneity of tree-ring series permitted to construct on their basis the tree-ring chronology of Sitka spruce. A significant positive correlation was found between radial increments of Sitka spruce and air temperatures of winter and spring months (January-April) and a negative relationship between radial increments and temperature of May. This study also showed a distinctly positive correlation between diameter growth and precipitation in July and November of the previous year, and precipitation in February and in summer season (June-August) of the current year. During years with low precipitation in summer or low temperatures in winter and spring all trees produced narrow tree-rings. The proportion of air temperature and precipitation in variation of radial increment of Sitka spruce, expressed by the coefficient of multiple determination, was 52%.
Diagnostic Importance of CA-125 in Detection of Recurrence and Progress of the Disease in Stages III and IV of Epithelial Ovarian Carcinoma
Authors: Đurđević Srđan , Stojanović Sanja , Vejnović Tihomir , Kopitović Vesna , Basta-Nikolić Marijana , Petrović Đorđe , Đorđević Aleksandra
Published: March 2008

Diagnostic Importance of CA-125 in Detection of Recurrence and Progress of the Disease in Stages III and IV of Epithelial Ovarian Carcinoma

In 60 patients operated in stages III and IV of epithelial ovarian carcinoma continuous determination of CA 125 from serum was done during the following 2 years. The main condition for entering the survey were elevated values of CA 125 in serum > 35 U/mL and histologically verified epithelial ovarian carcinoma. The aim of the survey was to perform statistical assessment of serum CA 125 determination in diagnostics of recurrence and progression of the disease in stages III and IV of epithelial ovarian carcinoma, and percentage (%) of false positive and negative results. Determination of CA 125 from serum during 2 postoperative years is a reliable but not completely certain diagnostic parameter in detection of the disease progression in stages III and IV of epithelial ovarian carcinoma (sensitivity 79.3%, specificity 97.1%, positive predictive value 91.2%, negative predictive value 92.4%, test accuracy 92.1%). False positive (0.7%) and false negative results (4.7%) of individual tests were present in 5.4% of all samples.
Decrease of Fibrinolytic Potential in the Occurence of Cerebral Ischemia
Authors: Vučković Biljana , Đerić Mirjana , Ilić Tatjana , Čanak Višnja , Žarkov Marija
Published: March 2008

Decrease of Fibrinolytic Potential in the Occurence of Cerebral Ischemia

One of the most present clinical manifestations of long and progressive atherothrombotic occurrences is the ischemic cerebrovascular insult, one of the leading causes of death and illness in the world. Lately, a growing number of scientists believe that disorders in the fibrinolytic mechanism function are the key to the occurrence of cerebral ischemia. The goal of this study is to investigate whether the disorder of the fibrinolytic mechanism has influence on the occurrence of ischemic cerebrovascular insult. Our study includes 90 examinees, 60 of which suffer from ischemic cerebrovascular insult and 30 are clinically healthy examinees forming the control group. The results of our investigation show that statistically a significantly larger number of patients has decreased fibrinolytic potential comparing with controls (p < 0.01). According to this, it has been noted that euglobulin lysis clot time in the patient group is significantly longer (p = 0.005). Statistically, no significant difference has been noted related to the activity of plasminogen (p = 0.085). Further on, the plasminogen activator inhibitor-1 values among the patients have been significantly higher (p = 6.20 x 10-11). Moreover, significantly higher values of tissue-type plasminogen activator antigen have been statistically noted in the patient group (p = 5.20 x 10-5). The results of this investigation impose the conclusions that the decrease in fibrinolytic potential affects the occurrence of ischemic cerebrovascular insult, that it is directly connected to the higher levels of plasminogen activator inhibitor-1 and that the growth of tissue-type plasminogen activator antigen concentration participates in the decrease of fibrinolytic potential among patients suffering from cerebral ischemia.
Poly(L‐lactide)‐degrading activity of a newly isolated bacterium
Authors: Kim Mal Nam , Kim Wan Gyu , Weon Hang Yeon , Lee Sun Hee
Published: March 2008

A new strain exhibiting poly(L‐lactic acid) (PLLA)‐degrading activity was isolated from the compost loaded with low‐molecular weight PLLA. The strain was rod‐shaped gram positive bacterium and was identified to be Bacillus licheniformis by the 16S rDNA sequence analysis. It degraded not only low‐molecular weight PLLA but also other PLLAs having higher molecular weight. The lower the molecular weight of PLLA, the faster the biodegradation rate. And thereby 45% and 81% of PLLAs with weight average molecular weight of 256,000 and 5,000, respectively, were metabolized into CO2 after 40 days of biodegradation at 58°C in the sterilized compost inoculated with the bacterium. According to the 16S rDNA sequence analysis, B. licheniformis PLLA‐2 belonged to Bacillus spp. phylogenetically. However, there existed almost no phylogenetic relationship between B. licheniformis PLLA‐2 and the previously reported PLLA‐degrading strains. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Thermal and mechanical properties of epoxy composites reinforced by a natural hydrophobic sand
Authors: Sui G. , Jana S. , Salehi‐khojin A. , Neema S. , Zhong W. H. , Chen H. , Huo Q.
Published: March 2008

If a low weight percentage of crude fine fillers can improve properties of polymer materials directly without complicated chemical treatment process involved, it will be significant for many industrial applications. Our previous study indicated that a kind of Cancun natural sand could be an effective filler material for polymer composites. In this current work, the epoxy composites reinforced by this kind of natural sand particles were prepared and thermal and mechanical properties of the composites containing up to 5 wt % of the sand particles were characterized. Results showed that the highest flexural strength appears in the epoxy composite containing 1 wt % sand particles. A damage model was used to interpret the flexural properties, which showed an acceptable agreement with the experimental results. The glass transition temperature, high temperature storage modulus, and dimensional stability of the sand/epoxy composites monotonically increased with the addition of the sand particles. The sand particle/epoxy composites also displayed a noticeable enhancement in thermal conductivity. Theoretical analysis showed that in addition to conduction, other heat transport mechanisms played roles in the improved heat transmission through the composites. As a natural porous micron‐scale material, Cancun sand has the potential for applications in cost‐effective composites with enhanced mechanical and thermal properties. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Structures and properties of ternary blends of recycled poly(ethylene terephthalate)/bisphenol‐A polycarbonate/(E/nBA/GMA)
Authors: Peng Yong , Guo Weihong , Zhu Ping , Wu Chifei
Published: March 2008

Recycled poly(ethylene terephthalate)/bisphenol‐A polycarbonate/PTW (ethylene, butylacrylate (BA), and glycidylmethacrylate (E/nBA/GMA) terpolymer) were blended in different sequence through low temperature solid state extrusion (LTSSE) was studied. R‐PET/PC blends were toughened by PTW, resulting in the improvement of impact strengths. In tensile test, the (PC/PTW)/r‐PET blends made by mixing r‐PET with the preblend of PC/PTW had noticeable strengthening effect on its tensile properties, which was not impaired by the rubber content due to its strain‐hardening occurred following its necking at the constant load. Morphological study by scanning electron microscopy (SEM) was in conformity with the mechanical result. For the (PC/PTW)/r‐PET blends, the PC particles were well embedded in the PET matrix and the smooth morphology exhibited. The DSC thermographs for heating and cooling run indicated that the crystallinity of PET rich phase was affected by different blending sequence. In the FTIR test, the different absorption intensity of PC aromatic carbonate carbonyl band was clearly illustrated. The results indicated different blending sequence led to different blending effect. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Fracture behavior of laminated wood bonded with water based polymer‐isocyanate resin and resorcinol‐formaldehyde resin under impact fatigue
Authors: Miyazaki Junko , Nakano Takato
Published: March 2008

The impact fatigue behavior of laminated wood bonded with water based polymer‐isocyanate resin (WPI) and resorcinol–formaldehyde resin (RF) was investigated. The number of cyclic blows to failure (Nb) for laminated wood was lower than that for solid wood. For laminated wood, Nb showed a significant decrease with an increase in temperature, while for solid wood, it showed a slight decrease. The fatigue life of laminated wood bonded with WPI was lower than that of RF. For laminated wood bonded with WPI, the ratio of the height of rebound (Qn) to that of the first rise (Pn), which was evaluated from an impact stress wave, remained constant and then gradually decreased before failure. This indicates that the energy consumed by heating increased before failure because the cured WPI has viscosity. For RF, Qn/Pn remained constant immediately before failure because cured RF is rigid. At a lower test temperature, the fracture surface almost entirely comprised the wood. As the temperature increased, the laminated wood fractured predominately in the adhesive layer. This could be attributed to a decrease in the rigidities of WPI and RF. The impact fatigue behavior of laminated wood is related to the mechanical properties of the adhesives. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation of sheath–core bicomponent composite ion‐exchange fibers and their properties
Authors: Ding Zhi‐Jia , Qi Lu
Published: March 2008

Based on sheath–core bicomponent composite ion‐exchange fibers with modified polystyrene and modified polypropylene, composite fibers were further crosslinked and sulfonated with chlorosulfonic acid to produce strongly acidic cation‐exchange fibers. The optimal technology of the obtained fibers was examined, and the structures of the fibers were investigated with Fourier transform infrared spectrophotometry, differential scanning calorimetry, and so forth. The properties were measured with chemical titration, filament strength instrumentation, scanning electron microscopy, and so forth. The results showed that cation‐exchange fibers with better mechanical properties and a higher exchange capacity were obtained, and they had higher practicability. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Relationship between the crystalline structure and mechanical behavior in isotropic and oriented polyamide 12
Authors: Dencheva Nadya , Denchev Zlatan , Oliveira M. Jovita , Nunes Teresa G. , Funari Sérgio S.
Published: March 2008

This study reports on the relationship between the crystalline structure and mechanical behavior of differently processed and annealed polyamide 12 (PA12) samples. Two sets of samples were obtained: isotropic PA12 films prepared by hot pressing and oriented cables prepared by consecutive extrusion and cold drawing. These samples were isothermally annealed in the range of 80–160°C and then subjected to tensile tests at room temperature. A combination of solid‐state 13C‐NMR and synchrotron wide‐ and small‐angle X‐ray scattering was used to obtain reliable structural data from these samples before and after the tensile tests. These structural data were related to the mechanical properties of the respective PA12 samples. Deformation models explaining all the experimental results were suggested for the different PA12 samples. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and characterization of dendronized aromatic polyamides with bromomethyl groups in the periphery
Authors: Miao Yanru , Wu Guoliang , Zhou Li , Xu Wei , Xia Xinnian , Xu Weijian
Published: March 2008

This paper focused on the synthesis of novel functionalized dendronized aromatic polyamides, which contained a polyamide backbone and polyamide dendrons decorated with bromomethyl groups, by the macromonomer route. The new activating procedure of the synthesis of dendrons and macromonomers using thionyl chloride as an activating agent eliminated the protection/deprotection procedure and reduced side reactions. The structures of the dendrons, macromonomers, and polyamides were confirmed by FTIR, 1H NMR, 13C NMR, and elemental analysis. The properties of the resulting dendronized polyamides, which were compared with that of the linear polyamide (LP), were studied using GPC, XRD, TGA, DSC, inherent viscosity measurement, and solubility experiment. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effect of the processing conditions and the addition of trans‐polyoctenylene rubber on the properties of natural rubber/styrene–butadiene rubber blends
Authors: Bizi Claudia Maria Pena , Demarquette Nicole R.
Published: March 2008

In this study, the influence of the processing conditions and the addition of trans‐polyoctenylene rubber (TOR) on Mooney viscosity, tensile properties, hardness, tearing resistance, and resilience of natural rubber/styrene–butadiene rubber blends was investigated. The results obtained are explained in light of dynamic mechanical and morphological analyses. Increasing processing time produced a finer blend morphology, which resulted in an improvement in the mechanical properties. The addition of TOR involved an increase in hardness, a decrease in tear resistance, and no effect on the resilience. It resulted in a large decrease in the Mooney viscosity and a slight decrease in the tensile properties if the components of the compounds were not properly mixed. The results indicate that TOR acted more as a plasticizer than a compatibilizer. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008