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Purpose To determine the optimal dose‐volume constraint for laryngeal sparing using three commonly employed intensity modulated radiation therapy (IMRT) approaches in patients with oropharyngeal cancer treated to the bilateral neck. Materials and methods Thirty patients with stage II‐IVA oropharynx cancers received definitive radiotherapy with split‐field IMRT (SF‐IMRT) to the bilateral neck between 2008 and 2013. Each case was re‐planned using whole‐field IMRT (WF‐IMRT) and volumetric modulated arc therapy (VMAT) and plan quality metrics and dose to laryngeal structures was evaluated. Two larynx volumes were defined and compared on the current study: the Radiation Therapy Oncology Group (RTOG) larynx as defined per the RTOG 1016 protocol and the MDACC larynx defined as the components of the larynx bounded by the superior and inferior extent of the thyroid cartilage. Results Target coverage, conformity, and heterogeneity indices were similar in all techniques. The RTOG larynx mean dose was lower with WF‐IMRT than SF‐IMRT (22.1 vs 25.8 Gy; P

Highlights • Early stage tonsillar cancers may be treated with unilateral neck radiotherapy (RT). • We performed a dosimetric study comparing three common radiotherapy modalities. • No significant differences in target coverage existed between all plans. • Laryngeal doses were reduced using whole-field intensity modulated RT and VMAT. • Shorter treatment times and required monitor units were also associated with VMAT., Background and purpose Minimizing radiation dose exposure to nearby organs is key to limiting clinical toxicities associated with radiotherapy. Several treatment modalities such as split- or whole-field intensity-modulated radiotherapy (SF-IMRT, WF-IMRT) and volumetric modulated arc therapy (VMAT) are being used to treat tonsillar cancer patients with unilateral neck radiotherapy. Herein, we provide a modern dosimetric comparison of all three techniques. Materials and methods Forty patients with tonsillar cancer treated with definitive, ipsilateral neck SF-IMRT were evaluated. Each patient was re-planned with WF-IMRT and VMAT techniques, and doses to selected organs-at-risk (OARs) including the larynx, esophagus, and brainstem were compared. Results No significant differences in target coverage existed between plans; however, the heterogeneity index improved using WF-IMRT and VMAT relative to SF-IMRT. Compared to SF-IMRT, WF-IMRT and VMAT plans had significantly lower mean doses to the supraglottic larynx (31 Gy, 18.5 Gy, 17 Gy; p

Ohlson and Aier (2009) propose a model of modified cash accounting (MCA) for analyzing and evaluating a firm’s cash flows. They suggest that MCA cash earnings provide a better measure of earnings than GAAP’s measure, and that the MCA bottom line is more informative because it identifies earnings due to operations on a cash- and approximate cash-equivalent basis. However, there is no empirical test for the information content of MCA cash earnings proposed by Ohlson and Aier (2009). This study empirically examines the incremental information content of MCA cash earnings compared with cash flow from operations (CFO) and GAAP earnings per share (EPS) using stock returns as the benchmark for firms’ performance during the 2001–2011 period. We find that MCA cash earnings provide incremental information content beyond CFO and EPS.

Purpose – The paper aims to clarify the relationship between earnings management and the sale of long‐lived assets and investments for firms listed in Taiwan. In addition, it suggests several interesting issues for further studies by proposing that positive earnings are one of the necessary conditions for the companies to issue bonds or new shares.Design/methodology/approach – The paper uses archival data and regression analysis to document empirical evidence that assets sales are one of the methods to manipulate reported earnings among 12,484 firm‐years over the period of 1984‐2006.Findings – The paper finds that approximately 54‐57 percent of firms in Taiwan with small pre‐managed earnings losses manipulate reported earnings to show small positive earnings. This is in contrast to 30‐40 percent of firms in the USA as reported by Burgstahler and Dichev.Research limitations/implications – The paper makes a good use of the unique institutional features of Taiwan. It has not produced other unique results tha...

We examine the market reaction to announcements of actual share repurchases, events that cluster both within and across firms. Using a multivariate regression model, we find that the market reacts positively to the events, indicating that these announcements provide additional information to that contained in the initial repurchase intention announcements. Further, the market response is especially favorable for firms with overinvestment problems as measured by Tobin's q, and is not related to signaling costs as measured by the size of the repurchase. Our findings generally support the hypothesis that share repurchases reduce the agency costs of excessive free cash flow.

This study investigates whether managers grant extended credit at the end of the fiscal year to accelerate customer purchases and thus avoid reporting losses. This study also considers whether this kind of earnings management affects the information content of reported earnings, and whether the unexpected accounts receivable (UAR)—a relatively reliable measure of management's exercise of channel stuffing over earnings—can provide incremental information about this phenomenon. Consistent with our hypotheses, we find that managers are likely to grant extended credit at the end of the fiscal year to meet their annual financial reporting targets.

Purpose Herpes simplex virus type I (HSV-1) is capable of causing a wide array of human ocular diseases. Herpes simplex virus keratitis (HSK)-induced cytopathogenicity together with the chronic immune-inflammatory reaction can trigger stromal scarring, thinning, and neovascularization which may lead to permanent vision impairment. Lychee flower extract (LFE) is known for its antioxidant and anti-inflammatory effects. Therefore, in this study, we investigated the mechanism of the Statens Seruminstitut rabbit corneal (SIRC) epithelial cells infected by HSV-1 and examined the antiviral capabilities of LFE. Methods SIRC cells were pretreated with different concentrations of LFE (0.2, 0.1, and 0.05 μg/ml) and then infected with 1 MOI of HSV-1 for 24 h. The cell viability or morphology was evaluated in this study. In addition, the supernatants and cell extracts were collected for Cell Counting Kit-8 (CCK), plaque assay, and western blotting. Results We found that HSV-1-induced cell proliferation is regulated through inhibition of the mammalian target of rapamycin (mTOR) and p70s6k phosphorylation in response to the LFE. In addition, the LFE enhanced the autophagy protein expression (Beclin-1 and light chain 3, LC3) and decreased the viral titers. Conclusions These results showed the antiviral capabilities and the protective effects of LFE. Taken together, our data indicate that LFE has potential as an anti-HSK (herpes simplex keratitis) for HSV-1 infection.

This paper examines whether firms which delay earnings announcements engage in earnings management. The cross–sectional version of the modified Jones 1995 model is used to estimate ‘normal’ accruals. Prior research has documented that, on average, delayed earnings announcements are associated with negative earnings surprises. Our evidence suggests that the market anticipates unfavorable earnings news when it observes reporting delays. As a consequence, late reporters appear to make the most of a bad situation by employing income–decreasing accruals in big–bath–type earnings management and in contractual renegotiations. We find that the magnitude of income–reducing abnormal accruals is related to the reporting lag.

This paper examines whether concessionary tax rates and tax incentives can attract foreign direct investment (FDI) into certain designated areas in China. Since China opened its doors to foreign investors in 1979, tax benefits have been used extensively to attract FDI into different areas. In 1991, a new tax law was introduced which superseded two previous income tax laws. This new law provides additional tax benefits which improve the investment environment for foreign investors. This study investigates the effect of China's tax rates and tax incentive policy on FDI and on the locational choices of foreign firms. Our empirical results indicate that tax rates and incentives are important determinants of regional investment decisions in China, after controlling for potential confounding variables covering infrastructure, unemployment rate, wage rate and agglomeration economics. Specifically, areas offering lower tax rates and increased tax incentives are found to attract greater amounts of FDI. The impetus of the tax effect on FDI is more apparent in the post-1991 period due to changes in the tax laws. Our results also suggest that infrastructure variables are important determinants of regional investment decisions.

This paper empirically tests Kim and Verrecchia's (1994, hereafter KV) theory that bid-ask spreads may increase around earnings announcements when information asymmetry increases between the informed traders and the less informed market-makers. Despite certain limitations, prior research has used analysts' earnings forecasts as a proxy for information asymmetry. I substitute the percentage of common stocks held by institutional investors as a more precise proxy for information asymmetry. Consistent with KV's proposition, I find (1) that bid-ask spreads increase at the time of earnings announcements, and (2) that bid-ask reactions to earnings announcements are significantly positively related to information asymmetry even after controlling for the effects of other cross-sectional determinants of spreads.

Scholes and Wolfson 1989 , Scholes and Wolfson 1992 ) argue that tax rules jointly influence investment decisions and organizational form. The present research uses Chinese data to test these assertions. Specifically, our study investigates whether (1) the creation of special tax incentive zones is an effective tax policy for China to induce new foreign direct investment (FDI) into specific regions, and (2) changes in the tax rules influence the particular form of foreign direct investment selected: equity joint ventures, contractual joint ventures, and wholly foreign-owned enterprises. Our results indicate that tax incentives are effective in attracting FDI to China, and moreover, influence the selection of a particular form of FDI. One limitation of our study is that we were unable to completely control for the correlated-omitted-variable problem.

Many accounting researchers use direct mail survey questionnaires as a means of data collection. There are many advantages in using mail surveys. For example, surveys are a cost‐effective and efficient means of collecting research data and they provide a means of obtaining data from a geographically diverse population. However, there are several potential problems associated with the use of questionnaires in general and mail survey questionnaires in particular. These include sampling bias, low response rates, response bias, and poor questionnaire design. Numerous suggestions and procedures have been proposed in the literature to reduce the impact of these factors — unfortunately, most of these suggestions have gone unheeded. A study recently published in this journal (Guilding and Kirman, 1998) is critiqued in order to point out the potential limitations associated with using survey questionnaires, and to indicate what researchers can do to mitigate the effects of these problems.

There is a growing belief that historical-cost accounting is no longer a relevant or reliable means of valuing a firm's assets and liabilities. Economists consider economic income relevant for measuring profit and performance, while they consider accounting income misleading for these purposes. The critical issue of measuring economic income has received little attention. The purpose of this paper is to point out some of the problems involved in computing economic income and to present ways in which accounting income can be adjusted to make it a more viable measurement.

This study investigates the effects of differences in predisclosure information asymmetry on trading volume reaction during quarterly earnings announcements. The analyses show that trading volume reaction to quarterly earnings announcements is positively related to the level of predisclosure information asymmetry and to the magnitude of the price reaction to the announcements. These results are consistent with Kim and Verrecchia's (1991a) theoretical trading volume proposition, and with Atiase and Bamber's (1994) tests of the proposition based on annual earnings announcements. This study also provides evidence on the relation of predisclosure information asymmetry and trading volume before and after quarterly earnings announcements.

A procedure has been developed using an electronic portal imaging device (EPID) to verify that the center of a patient's lesion is aligned with the center of a treatment cone prior to treatment in a linac-based stereotactic radiosurgery procedure. The coordinates of the lesion center are set on the Brown-Roberts-Wells phantom base using a target simulator. A 3 mm tungsten ball, mounted on the target simulator, is used as the reference point for the planned isocenter. The target simulator is then attached to an adapter mounted on the linac couch, and an EPID image of the simulated target is acquired. The center of the circular-shaped radiation field is calculated from the centroid of the segmented EPID image, and the center of the tungsten ball is identified by an automated computer search algorithm. A summation filter is used to find the position of the lowest radiation intensity coincident with the center of the ball. The alignment error is defined as the difference between the center of the radiation field and the center of the ball. The accuracy of this method was tested and found to be within 0.2 mm. The advantage of the EPID-based procedure is that it can give quantitative offset values quickly for immediate readjustment. We have found that the method is also a convenient tool for testing room laser alignment and the accuracy of the treatment cones.

A computer-controlled miniature multileaf collimator (MMLC) with 4 mm leaf width and a maximum field size of 6 cm X 6 cm has been designed as a tertiary beam-shaping device for linac-based stereotactic radiosurgery. The purpose of this study is to develop an accurate and efficient dose calculation model for use with the MMLC. A pencil-beam based algorithm using a sum of three Gaussian kernels was developed to model the off-axis ratio of MMLC fields. Because the kernel integration over a rectangular field can be solved in closed form, dose to any point from an arbitrary MMLC field can be calculated efficiently by summing dose contribution from a set of rectangular apertures and transmission blocks that model individual leaf openings or leaf transmissions. The model uses an effective rectangular field and equivalent square method for determination of depth dose and dose output. Results showed that the calculated percentage depth dose was within 1% and output factor was within 1.5% of measured data. The parameters of the pencil beam kernels were extracted by fitting measured off-axis profiles for a few field sizes at a few depths. The accuracy of the calculated off-axis ratio was tested by comparison with measured data for a number of MMLC fields. The algorithm was shown to be accurate to within 1.5% or 1 mm for off-axis ratios. The algorithm computes at a speed of 34,600 data points per second on a DEC Alpha server model 2000/433 (Digital Equipment Corp., Maynard, MA), which is about 15 times faster than a Clarkson-type summation method.

A procedure is described to calculate the monitor unit ratios required to produce effective wedge fields having a desired wedge angle by combining an internal 60 degrees wedge with an open field. Complementary procedures are derived and demonstrated for calculating the effective wedge dose distributions with wedge angles of 15 degrees, 30 degrees, and 45 degrees using the central axis depth dose data and off-axis ratios of the open field and the 60 degrees wedged field. Measurements at five points on and off the central axis within each field and measurements of the effective wedge factor demonstrated that the calculated wedge distributions were correctly delivered to within 2% in all cases.

The Collaborative Working Group (CWG) of the National Cancer Institute (NCI) electron beam treatment planning contract has performed a set of 14 experiments that measured dose distributions for 28 unique beam-phantom configurations that simulated various patient anatomic structures and beam geometries. Multiple dose distributions were measured with film or diode detectors for each configuration, resulting in 78, 2-D planar dose distributions and one, 1-D depth-dose distribution. Measurements were made for 9- and 20-MeV electron beams, using primarily 6{times}6- and 15{times}15-cm applicators at several SSDs. Dose distributions were measured for shaped fields, irregular surfaces, and inhomogeneities (1-D, 2-D, and 3-D), which were designed to simulate many clinical electron treatments. The data were corrected for asymmetries, and normalized in an absolute manner. This set of measured data can be used for verification of electron beam dose algorithms and is available to others for that purpose.