124 research outputs found

    Communication during the Pandemic: Use of videoconferencing in Audit Committee-Auditor Communication

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    Using Korean listed firms’ mandatory disclosure on the communication method for meetings between the Audit Committee and auditors from 2019 to 2020, we find that videoconferencing leads to weaker audit quality. We measure the degree of videoconferencing by the proportion of videoconferencing in the total number of meetings between the Audit Committee and auditors. We provide preliminary results on whether changes in communication methods affect audit quality. Our results are robust to change analyses, balanced sample analyses, including auditor fixed effects, and using an alternative measure of audit quality and videoconferencing. We find that Audit Committee independence or expertise does not affect the relationship between videoconferencing and audit quality but holding more formal Audit Committee meetings during the year mitigates the negative impact of videoconferencing on audit quality. Our paper contributes to the literature on information processing of Audit Committees

    The Effect of Imbalanced Carrier Transport on the Efficiency Droop in GaInN-Based Blue and Green Light-Emitting Diodes

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    The effect of strongly-imbalanced carrier concentration and mobility on efficiency droop is studied by comparing the onset voltage of high injection, the onset current density of the droop, and the magnitude of the droop, as well as their temperature dependence, of GaInN-based blue and green light-emitting diodes (LEDs). An n-to-p asymmetry factor is defined as sigma(n)/sigma(p), and was found to be 17.1 for blue LEDs and 50.1 for green LEDs. Green LEDs, when compared to blue LEDs, were shown to enter the high-injection regime at a lower voltage, which is attributed to their less favorable p-type transport characteristics. Green LEDs, with lower hole concentration and mobility, have a lower onset current density of the efficiency droop and a higher magnitude of the efficiency droop when compared to blue LEDs. The experimental results are in quantitative agreement with the imbalanced carrier transport causing the efficiency droop, thus providing guidance for alleviating the phenomenon of efficiency droop.114sciescopu

    Enhanced overall efficiency of GaInN-based light-emitting diodes with reduced efficiency droop by Al-composition-graded AlGaN/GaN superlattice electron blocking layer

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    AlxGa1-xN/GaN superlattice electron blocking layers (EBLs) with gradually decreasing Al composition toward the p-type GaN layer are introduced to GaInN-based high-power light-emitting diodes (LEDs). GaInN/GaN multiple quantum well LEDs with 5- and 9-period Al-composition-graded AlxGa1-xN/GaN EBL show comparable operating voltage, higher efficiency as well as less efficiency droop than LEDs having conventional bulk AlGaN EBL, which is attributed to the superlattice doping effect, enhanced hole injection into the active region, and reduced potential drop in the EBL by grading Al compositions. Simulation results reveal a reduction in electron leakage for the superlattice EBL, in agreement with experimental results. (C) 2013 AIP Publishing LLC.open1133sciescopu

    Energy bandgap variation in oblique angle-deposited indium tin oxide

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    Indium tin oxide (ITO) thin films deposited using the oblique angle deposition (OAD) technique exhibit a strong correlation between structural and optical properties, especially the optical bandgap energy. The microstructural properties of ITO thin films are strongly influenced by the tilt angle used during the OAD process. When changing the tilt angle, the refractive index, porosity, and optical bandgap energy of ITO films also change due to the existence of a preferential growth direction at the interface between ITO and the substrate. Experiments reveal that the ITO film's optical bandgap varies from 3.98 eV (at normal incident deposition) to 3.87 eV (at a 60 tilt angle). 2-10 OAD is generally associated with physical vapor deposition of thin films (prepared through, e.g., electron-beam or thermal evaporation), in which the material vapor flux arrives at the substrate surface at an oblique angle. Tilted and columnar nanostructures are the most typical morphological characteristics of OAD thin films. 1, Deposition of ITO films on soda lime glass and silicon substrates was conducted with an E-beam evaporation system using an ITO source composed of 90 wt. % In 2 O 3 and 10 wt. % SnO 2 . Prior to the deposition, all substrates were sequentially cleaned in acetone, isopropyl alcohol, and deionized water and dried under nitrogen flow. The apparatus used in our OAD process has a sample stage (onto which the substrate was loaded), allowing for control of the polarangle as well as azimuthal rotation. The distance between the substrate and evaporation source material was approximately 50 cm. The sample stage was positioned at a fixed polar angle so that the substrate had a certain tilt angle (deposition angle) with respect to the vapor-flux direction. The chamber was evacuated to a pressure less than 1.0 Â 10 À6 Torr, and substrates were held at room temperature. During the deposition, the deposition rate was held steady at 0.2 nm/s, as measured by a quartz crystal monitor inside the chamber. The low growth rate on the substrate at higher deposition angles 11 was compensated by increasing the deposition time to keep the same film thickness for all samples. The ITO films unloaded from the E-beam evaporation system were annealed in O 2 at 550 C for 1 min in a rapid thermal annealing system in order to compensate a deficiency of oxygen in the films. Optical transmittance measurements of the ITO thin films were performed using non-polarized light at normal incidence in the wavelength range of 280-780 nm using a JASCO UV-VIS spectrophotometer. The refractive index (n) was measured using a spectroscopic ellipsometry system, in which absorption is neglected during fitting. A film thickness was measured first by ellipsometry, and then confirmed by a scanning electron microscope (SEM, Hitachi S-4300). The porosity and optical bandgap energy values of the ITO thin films were calculated using theoretical models developed by Poxson et al. 11 and Tauc, 13 respectively. The morphological features of the films were examined using an optical microscope and SEM. Several regions on the sample surface were investigated in order to produce representative images. Furthermore, the crystallographic structure of the ITO thin films was examined by X-ray diffraction (XRD) using the nickel-filtered Ka emission of copper. Figures 1(a) and 1(b) show optical microscope images of the ITO films deposited on (a) silicon (Si) and (b) glass substrates at tilt angles ranging from 0 to 60 . A color difference of the ITO thin films is clearly evident, which can result from a variation in thickness and/or refractive index. In this case, because the thicknesses of all films are the same (about 210 nm), the variation in refractive index is the cause for the color variation. It is well known that the refractive index of a a

    A Functional Polymorphism on Chromosome 15q25 Associated with Survival of Early Stage Non–Small-Cell Lung Cancer

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    Introduction:The 15q25 region has been associated with lung-cancer risk and might also be associated with the prognosis of lung cancer. This study was conducted to determine the impact of a functional polymorphism in the CHRNA3 gene on chromosome 15q25 in the survival of patients with early-stage non–small-cell lung cancer (NSCLC).Methods:Five hundred and eighty-three consecutive patients with surgically resected NSCLC were enrolled. The rs6495309C > T polymorphism in the promoter of the CHRNA3 gene was investigated. The association between genotype and overall survival (OS) and disease-free survival (DFS) was analyzed.Results:Patients with the rs6495309 CT or TT genotype had a significantly better OS and DFS than the rs6495309 CC genotype (adjusted hazard ratio for OS = 0.56, 95% confidence interval = 0.41–0.75, p = 0.0001; and adjusted hazard ratio for DFS = 0.61, 95% confidence interval = 0.48–0.79, p = 0.0001). An association between the rs6495309C > T polymorphism and survival outcome was demonstrated in smokers and never-smokers, and in squamous-cell carcinomas and adenocarcinomas.Conclusion:The CHRNA3 rs6495309C > T polymorphism may affect survival in patients with early-stage NSCLC. Analysis of the rs6495309C > T polymorphism can help identify patients at high risk of a poor disease outcome

    International Survey to Establish Prioritized Outcomes for Trials in People With Coronavirus Disease 2019.

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    OBJECTIVES: There are over 4,000 trials conducted in people with coronavirus disease 2019. However, the variability of outcomes and the omission of patient-centered outcomes may diminish the impact of these trials on decision-making. The aim of this study was to generate a consensus-based, prioritized list of outcomes for coronavirus disease 2019 trials. DESIGN: In an online survey conducted in English, Chinese, Italian, Portuguese, and Spanish languages, adults with coronavirus disease 2019, their family members, health professionals, and the general public rated the importance of outcomes using a 9-point Likert scale (7-9, critical importance) and completed a Best-Worst Scale to estimate relative importance. Participant comments were analyzed thematically. SETTING: International. SUBJECTS: Adults 18 years old and over with confirmed or suspected coronavirus disease 2019, their family members, members of the general public, and health professionals (including clinicians, policy makers, regulators, funders, and researchers). INTERVENTIONS: None. MEASUREMENTS: None. MAIN RESULTS: In total, 9,289 participants from 111 countries (776 people with coronavirus disease 2019 or family members, 4,882 health professionals, and 3,631 members of the public) completed the survey. The four outcomes of highest priority for all three groups were: mortality, respiratory failure, pneumonia, and organ failure. Lung function, lung scarring, sepsis, shortness of breath, and oxygen level in the blood were common to the top 10 outcomes across all three groups (mean > 7.5, median ≥ 8, and > 70% of respondents rated the outcome as critically important). Patients/family members rated fatigue, anxiety, chest pain, muscle pain, gastrointestinal problems, and cardiovascular disease higher than health professionals. Four themes underpinned prioritization: fear of life-threatening, debilitating, and permanent consequences; addressing knowledge gaps; enabling preparedness and planning; and tolerable or infrequent outcomes. CONCLUSIONS: Life-threatening respiratory and other organ outcomes were consistently highly prioritized by all stakeholder groups. Patients/family members gave higher priority to many patient-reported outcomes compared with health professionals.The project is funded by the Flinders University and the National COVID-19 Clinical Evidence Taskforce, convened by the Australian Living Evidence Consortium, hosted by Cochrane Australia, School of Public Health and Preventive Medicine, Monash University supported by the Australian Government, Victorian Department of Health and Human Services, Ian Potter Foundation, Walter Cottman Endowment Fund (managed by Equity Trustees) and the Lord Mayor's Charitable Foundation). AT is supported by The University of Sydney Robinson Fellowship. ACM is supported by a Clinical Research Career Development Fellowship from the Wellcome Trust (WT 2055214/Z/16/Z

    Core Outcomes Set for Trials in People With Coronavirus Disease 2019.

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    OBJECTIVES: The outcomes reported in trials in coronavirus disease 2019 are extremely heterogeneous and of uncertain patient relevance, limiting their applicability for clinical decision-making. The aim of this workshop was to establish a core outcomes set for trials in people with suspected or confirmed coronavirus disease 2019. DESIGN: Four international online multistakeholder consensus workshops were convened to discuss proposed core outcomes for trials in people with suspected or confirmed coronavirus disease 2019, informed by a survey involving 9,289 respondents from 111 countries. The transcripts were analyzed thematically. The workshop recommendations were used to finalize the core outcomes set. SETTING: International. SUBJECTS: Adults 18 years old and over with confirmed or suspected coronavirus disease 2019, their family members, members of the general public and health professionals (including clinicians, policy makers, regulators, funders, researchers). INTERVENTIONS: None. MEASUREMENTS: None. MAIN RESULTS: Six themes were identified. "Responding to the critical and acute health crisis" reflected the immediate focus on saving lives and preventing life-threatening complications that underpinned the high prioritization of mortality, respiratory failure, and multiple organ failure. "Capturing different settings of care" highlighted the need to minimize the burden on hospitals and to acknowledge outcomes in community settings. "Encompassing the full trajectory and severity of disease" was addressing longer term impacts and the full spectrum of illness (e.g. shortness of breath and recovery). "Distinguishing overlap, correlation and collinearity" meant recognizing that symptoms such as shortness of breath had distinct value and minimizing overlap (e.g. lung function and pneumonia were on the continuum toward respiratory failure). "Recognizing adverse events" refers to the potential harms of new and evolving interventions. "Being cognizant of family and psychosocial wellbeing" reflected the pervasive impacts of coronavirus disease 2019. CONCLUSIONS: Mortality, respiratory failure, multiple organ failure, shortness of breath, and recovery are critically important outcomes to be consistently reported in coronavirus disease 2019 trials

    Design of a CMOS Image Sensor with Bi-Directional Gamma-Corrected Digital-Correlated Double Sampling

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    We present a 640 × 480 CMOS image sensor (CIS) with in-circuit bi-directional gamma correction with a proposed digital-correlated double sampling (CDS) structure. To operate the gamma correction in the CIS, the transfer function of the analog-to-digital converter can be changed by controlling the clock frequency of the counter using analog CDS. However, the analog CDS is vulnerable to capacitor mismatch, clock feedthrough, etc. Therefore, we propose a digital-CDS method with a hold-and-go counter structure to operate the bi-directional gamma correction in the CIS. The proposed CIS achieves a 10-bit resolution using a global log-exponential counter and configurable column reset counter with a resolution of 8/9 bits. The sensor was fabricated in a 0.11 μm CIS process, and the full chip area was 5.9 mm × 5.24 mm. The measurement results showed a maximum SNR improvement of 10.41% with the proposed bi-directional gamma-corrected digital-CDS with the hold-and-go counter. The total power consumption was 6.3 mW at a rate of 16.6 frames per second with analog, pixel, and digital supply voltages of 3.3 V, 3.3 V, and 1.5 V, respectively
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