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Abstract Oxidative stress from excess H2O2 activates transcription factors that restore redox balance and repair oxidative damage. Although many transcription factors are activated by H2O2, it is unclear whether they are activated at the same H2O2 concentration, or time. Dose-dependent activation is likely as oxidative stress is not a singular state and exhibits dose-dependent outcomes including cell-cycle arrest and cell death. Here, we show that transcription factor activation is both dose-dependent and coordinated over time. Low levels of H2O2 activate p53, NRF2 and JUN. Yet under high H2O2, these transcription factors are repressed, and FOXO1, NF-κB, and NFAT1 are activated. Time-lapse imaging revealed that the order in which these two groups of transcription factors are activated depends on whether H2O2 is administered acutely by bolus addition, or continuously through the glucose oxidase enzyme. Finally, we provide evidence that 2-Cys peroxiredoxins control which group of transcription factors are activated.

Optimal joint production decision, joint product selling prices and joint cost allocations for a monopoly firm can be determined simultaneously through a net realizable value. The model eliminates the interdependency problem between product cost and prices using the nonlinear programming approach. It is applicable for imperfectly competitive firms with which the ordinary cost-pricing policies cannot apply.

The stochastic demand cost-volume-profit (CVP) model has recently received considerable attention. For this model, management must determine optimal production prior to knowing the actual demand, a stochastic variable with known distribution. Management must choose the production quantity to balance prospects for sales revenue against risks of losses from shortages and from unsold items. This paper develops an expected return on investment criterion model for determining the optimal production quantity. Formulas and solution methods applicable to general demand distributions are obtained. A special solution technique for normally distributed demand is presented. The resulting choice criterion offers the advantages inherent in return rate methods. In addition, compared to a profit maximization approach, the expected rate of return on investment criterion is more widely applicable. [ABSTRACT FROM AUTHOR]

Community Multiscale Air Quality (CMAQ) model simulations utilizing the volatility basis set (VBS) treatment for organic aerosols (CMAQ-VBS) were evaluated against measurements collected at routine monitoring networks (Chemical Speciation Network (CSN) and Interagency Monitoring of Protected Visual Environments (IMPROVE)) and those collected during the 2010 California at the Nexus of Air Quality and Climate Change (CalNex) field campaign to examine important sources of organic aerosol (OA) in southern California. CMAQ-VBS (OA lumped by volatility, semivolatile POA) underpredicted total organic carbon (OC) at CSN (-25.5% Normalized Median Bias (NMdnB)) and IMPROVE (-63.9% NMdnB) locations and total OC was underpredicted to a greater degree compared to the CMAQ-AE6 (9.9 and -55.7% NMdnB, respectively; semi-explicit OA treatment, SOA lumped by parent hydrocarbon, nonvolatile POA). However, comparisons to aerosol mass spectrometer (AMS) measurements collected at Pasadena, CA indicated that CMAQ-VBS better represented the diurnal profile and the primary/secondary split of OA. CMAQ-VBS secondary organic aerosol (SOA) underpredicted the average measured AMS oxygenated organic aerosol (OOA, a surrogate of SOA) concentration by a factor of 5.2 (4.7 µg m-3 measured vs. 0.9 µg m-3 modeled), a considerable improvement to CMAQ-AE6 SOA predictions, which were approximately 24× lower than the average AMS OOA concentration. We use two new methods, based on species ratios and on a simplified SOA parameterization from the observations, to apportion the SOA underprediction for CMAQ-VBS to too slow photochemical oxidation (estimated as 1.5× lower than observed at Pasadena using - log (NOx: NOy)), low intrinsic SOA formation efficiency (low by 1.6 to 2× for Pasadena), and too low emissions or too high dispersion for the Pasadena site (estimated to be 1.6 to 2.3× too low/high). The first and third factors will be similar for CMAQ-AE6, while the intrinsic SOA formation efficiency for that model is estimated to be too low by about 7×. For CMAQ-VBS, 90% of the anthropogenic SOA mass formed was attributed to aged secondary semivolatile vapors (70% originating from volatile organic compounds (VOCs) and 20% from intermediate volatility compounds (IVOCs)). From source-apportioned model results, we found most of the CMAQ-VBS modeled POA at the Pasadena CalNex site was attributable to meat cooking emissions (48%, and consistent with a substantial fraction of cooking OA in the observations), compared to 18% from gasoline vehicle emissions, 13% from biomass burning (in the form of residential wood combustion), and 8% from diesel vehicle emissions. All "other" inventoried emission sources (e.g. industrial/point sources) comprised the final 13%. The CMAQ-VBS semivolatile POA treatment underpredicted AMS hydrocarbon-like OA (HOA) + cooking-influenced OA (CIOA) at Pasadena by a factor of 1.8 (1.16 µg m-3 modeled vs. 2.05 µg m-3 observed) compared to a factor of 1.4 overprediction of POA in CMAQ-AE6, but did well to capture the AMS diurnal profile of HOA and CIOA, with the exception of the midday peak. We estimated that using the National Emission Inventory (NEI) POA emissions without scaling to represent SVOCs underestimates SVOCs by ~1.7×. [ABSTRACT FROM AUTHOR]

Utilizing an aircraft-specific parameterization based on smog chamber data in the Community Multiscale Air Quality (CMAQ) model with the volatility basis set (VBS), we estimated contributions of non-traditional secondary organic aerosols (NTSOA) for aircraft emissions during landing and takeoff (LTO) activities at the Hartsfield-Jackson Atlanta International Airport. NTSOA, formed from the oxidation of semi-volatile and intermediate volatility organic compounds (S/IVOCs), is a heretofore unaccounted component of fine particulate matter (PM2.5) in most air quality models. We expanded a prerelease version of CMAQ with VBS implemented for the Carbon Bond 2005 (CB05) chemical mechanism to use the Statewide Air Pollution Research Center 2007 (SAPRC-07) chemical mechanism and added species representing aircraft S/IVOCs and corresponding NTSOA oxidation products. Results indicated that the maximum monthly average NTSOA contributions occurred at the airport and ranged from 2.4 ng m-3 (34% from idle and 66% from non-idle aircraft activities) in January to 9.1 ng m-3 (33 and 67%) in July. This represents 1.7% (of 140 ng m-3) in January and 7.4% in July (of 122 ng m-3) of aircraft-attributable PM2.5 compared to 41.0-42.0% from elemental carbon and 42.8-58.0% from inorganic aerosols. As a percentage of PM2.5, impacts were higher downwind of the airport, where NTSOA averaged 4.6-17.9% of aircraft-attributable PM2.5 and, considering alternative aging schemes, was as high as 24.0% - thus indicating the increased contribution of aircraft-attributable SOA as a component of PM2.5. However, NTSOA contributions were generally low compared to smog chamber results, particularly at idle, due to the considerably lower ambient organic aerosol concentrations in CMAQ compared to those in the smog chamber experiments. [ABSTRACT FROM AUTHOR]

Co-located measurements of fine particulate matter (PM2.5) organic carbon (OC), elemental carbon, radiocarbon (14C), speciated volatile organic compounds (VOCs), and OH radicals during the CalNex field campaign provide a unique opportunity to evaluate the Community Multiscale Air Quality (CMAQ) model's representation of organic species from VOCs to particles. Episode average daily 23 h average 14C analysis indicates PM2.5 carbon at Pasadena and Bakersfield during the CalNex field campaign was evenly split between contemporary and fossil origins. CMAQ predicts a higher contemporary carbon fraction than indicated by the 14C analysis at both locations. The model underestimates measured PM2.5 organic carbon at both sites with very little (7% in Pasadena) of the modeled mass represented by secondary production, which contrasts with the ambient-based SOC/OC fraction of 63% at Pasadena. Measurements and predictions of gas-phase anthropogenic species, such as toluene and xylenes, are generally within a factor of 2, but the corresponding SOC tracer (2,3-dihydroxy-4-oxo-pentanoic acid) is systematically underpredicted by more than a factor of 2. Monoterpene VOCs and SOCs are underestimated at both sites. Isoprene is underestimated at Pasadena and overpredicted at Bakersfield and isoprene SOC mass is underestimated at both sites. Systematic model underestimates in SOC mass coupled with reasonable skill (typically within a factor of 2) in predicting hydroxyl radical and VOC gas-phase precursors suggest error(s) in the parameterization of semivolatile gases to form SOC. Yield values (α) applied to semivolatile partitioning species were increased by a factor of 4 in CMAQ for a sensitivity simulation, taking into account recent findings of underestimated yields in chamber experiments due to gas wall losses. This sensitivity resulted in improved model performance for PM2.5 organic carbon at both field study locations and at routine monitor network sites in California. Modeled percent secondary contribution (22% at Pasadena) becomes closer to ambient-based estimates but still contains a higher primary fraction than observed. [ABSTRACT FROM AUTHOR]

In this paper, we propose a multi-group SIR to simulate the spread of COVID-19 in an island context. The multi-group aspect enables us to modelize transmissions of the virus between non-vaccinated individuals within an age group as well as between different age groups. In addition, fuzzy subsets and aggregation operators are used to account for the increased risks associated with age and obesity within these different groups. From a conceptual point of view, the model emphasizes the notion of Hospitalization which is the major stake of this pandemic by replacing the compartment R (Removed) by compartment H (Hospitalization). The experimental results were carried out using medical and demographic data from the archipelago, Guadeloupe (French West Indies) in the Caribbean. These results show that without the respect of barrier gestures, a first wave would concern the elderly then a second the adults and the young people, which conforms to the real data.

This study examined the impacts of aircraft emissions during the landing and takeoff cycle on PM2.5 concentrations during the months of June and July 2002 at the Hartsfield-Jackson Atlanta International Airport. Primary and secondary pollutants were modeled using the Advanced Modeling System for Transport, Emissions, Reactions, and Deposition of Atmospheric Matter (AMSTERDAM). AMSTERDAM is a modified version of the Community Multiscale Air Quality (CMAQ) model that incorporates a plumein- grid process to simulate emissions sources of interest at a finer scale than can be achieved using CMAQ's model grid. Three fundamental issues were investigated: the effects of aircraft on PM2.5 concentrations throughout northern Georgia, the differences resulting from use of AMSTERDAM's plume-in-grid process rather than a traditional CMAQ simulation, and the concentrations observed in aircraft plumes at subgrid scales. Comparison of model results with an air quality monitor located in the vicinity of the airport found that normalized mean bias ranges from -77.5% to 6.2% and normalized mean error ranges from 40.4% to 77.5 %, varying by species. Aircraft influence average PM2.5 concentrations by up to 0.232 µgm-3 near the airport and by 0.001-0.007 µgm-3 throughout the Atlanta metro area. The plume-in-grid process increases concentrations of secondary PM pollutants by 0.005-0.020 µgm-3 (compared to the traditional grid-based treatment) but reduces the concentration of non-reactive primary PM pollutants by up to 0.010 µgm-3, with changes concentrated near the airport. Examination of subgrid-scale results indicates that median aircraft contribution to grid cells is higher than median puff concentration in the airport's grid cell and outside of a 20 km×20 km square area centered on the airport, while in a 12 km×12 km square ring centered on the airport, puffs have median concentrations over an order of magnitude higher than aircraft contribution to the grid cells. Maximum puff impacts are seen within the 12 km×12 km ring, not in the airport's own grid cell, while maximum grid cell impacts occur within the airport's grid cell. Twenty-one (21)% of all aircraft-related puffs from the Atlanta airport have at least 0.1 µgm-3 PM2.5 concentrations. Near the airport, median daily puff concentrations vary between 0.017 and 0.134 µgm-3 (0.05 and 0.35 µgm-3 at ground level), while maximum daily puff concentrations vary between 6.1 and 42.1 µgm-3 (7.5 and 42.1 µgm-3 at ground level) during the 2-month period. In contrast, median daily aircraft contribution to grid concentrations varies between 0.015 and 0.091 µgm-3 (0.09 and 0.40 µgm-3 at ground level), while the maximum varies between 0.75 and 2.55 µgm-3 (0.75 and 2.0 µgm-3 at ground level). Future researchers may consider using a plume-in-grid process, such as the one used here, to understand the impacts of aircraft emissions at other airports, for proposed future airports, for airport expansion projects under various future scenarios, and for other national-scale studies specifically when the maximum impacts at fine scales are of interest. [ABSTRACT FROM AUTHOR]

This study examines the impact of public venture capital (hereafter PVC) investments on corporate governance of initial public offering (hereafter IPO) firms in emerging markets. Using data collected from Taiwan PVC investments during 1996-2005, we analyse three corporate governance features in IPO firms: earnings management, board characteristics, and excess control by controlling shareholders. We find that PVC-backed firms use fewer accounting accruals in their IPO financial statements than non-PVC-backed firms. This result suggests that PVC-backed IPO firms engage in less earnings management than non-PVC-backed IPO firms. We also find PVC-backed firms tend to set up their boards with fewer non-independent directors and supervisors at IPO. This result indicates that PVC-backed IPO firms have better board structures than non-PVC-backed IPO firms. Finally, we find that controlling shareholders are less likely to exert excess control in PVC-backed firms than in non-PVC-backed firms. Overall, our results indicate that PVC investments add value to new IPO firms not only in financing their capital needs but also in creating better corporate governance structures in emerging markets. [ABSTRACT FROM AUTHOR]

We examine the impact on share prices of firms whose CEOs and CFOs certify their financial statements under oath, pursuant to the administrative order issued by the SEC on June 27, 2002. We hypothesize that (1) the certification provides assurance to investors by making disclosure more credible and by reducing information asymmetry between owners and management, and (2) the assurance value of certification is reflected in the stock price of the certifying company. Overall, the empirical results are consistent with our hypotheses. We observe, on average, positive abnormal returns for firms whose CEOs/CFOs certified their financial statements by August 14, 2002. Based on an analysis of bid-ask spreads, certifying firms experienced a significant decline in information asymmetry after certification. In cross-sectional analyses, we find abnormal returns are positively associated with firms that were under investigation, that used Andersen as their auditor, and that practiced aggressive revenue recognition. [ABSTRACT FROM AUTHOR]

This article focuses on the development of a scale to measure task completion motivation. This effort of scale development was suggested by the senior author's introspective observations of the strong tensions produced by uncompleted projects and the strong sense of satisfaction produced when a project was completed. On the basis of the thinking described above, a number of forced-choice items that deal with activities engaged in by adults and college students were developed. One choice was concerned with completing a task once it was started, while the other represented a lack of concern about completing the task.

This article reports that researchers recently reviewed the literature relative to neuropsychological deficits attributable to extended alcohol abuse. Immediately after a period of extended drinking, hospitalized patients suffer a variety of symptoms including tremulousness, clouding of consciousness, concentration difficulties, memory defects, and in some cases, delerium tremens and/or susceptibility to seizures. The general procedure involved contacting new admissions to two alcoholic treatment programs and scheduling them for individual testing.

Use of the net realizable value approach for joint manufacturing cost allocations requires knowledge of selling prices of joint products. However, joint product selling prices themselves are functions of the allocated costs under a cost-plus pricing policy. In this case, it is necessary to determine joint cost allocations and joint product prices simultaneously. This paper applies a nonlinear programming (NLP) approach to simultaneously determine the optimal joint production decision, joint product cost-plus prices, and joint cost allocations using the net realizable value method. The NLP solution provides not only the optimal joint production and pricing decisions, but also the necessary conditions for such optimal decisions. [ABSTRACT FROM AUTHOR]

Learning curves have important implications for managerial planning and control. This paper considers the effect of learning on managerial planning models for product mix problems that can he handled by a linear-programming formulation. An approach to incorporate learning effects in the planning model is proposed in this paper. The feasibility and superiority of the proposed approach over the traditional approach are discussed through the use of a linear-programming problem. [ABSTRACT FROM AUTHOR]

This article focuses on a study which analyzed the predictability of quarterly cash flows and developed cash flow forecasting models for predicting their future values. The study used the quarterly cash flows from operations to determine the statistical properties of cash flows and used the existing forecasting models of the Box-Jenkins' procedures to identify the model which best fits the available data. Accordingly, the objectives of the study are to determine the predictability of cash flows and develop forecasting models for predicting future cash flows using its past values, to test and compare the developed forecasting models with other forecasting models, to examine the effects of aggregation of data on the predictive ability of a cash flow forecasting model.

Trimidox (3,4,5-trihydroxybenzamidoxime), a newly synthesized analog of didox (N,3,4-trihydroxybenzamide) reduced the activity of ribonucleotide reductase (EC 1.17.4.1) in extracts of L1210 cells by 50% (50% growth-inhibitory concentration, IC50) at 5 microM, whereas hydroxyurea, the only ribonucleotide reductase inhibitor in clinical use, exhibited an IC50 of 500 microM. Ribonucleotide reductase activity was also measured in situ by incubating L1210 cells for 24 h with trimidox at 7.5 microM, a concentration that inhibits cell proliferation by 50% (IC50) or at 100 microM for 2 h; these concentrations resulted in a decrease in enzyme activity to 22% and 50% of the control value, respectively. Trimidox and hydroxyurea were cytotoxic to L1210 cells with IC50 values of 7.5 and 50 microM, respectively. Versus ribonucleotide reductase, trimidox and hydroxyurea yielded IC50 values of 12 and 87 microM, respectively. A dose-dependent increase in life span was observed in mice bearing intraperitoneally transplanted L1210 tumors. Trimidox treatment (200 mg/kg; q1dx9) significantly increased the life span of mice bearing L1210 leukemia (by 82% in male mice and 112% in female mice). The anti-tumor activity appeared more pronounced in female mice than in male mice. Viewed in concert, these findings suggest that trimidox is a new and potent inhibitor of ribonucleotide reductase and that it is a promising candidate for the chemotherapy of cancer in humans. [ABSTRACT FROM AUTHOR]

While some of the product quality costs are recorded in current accounting systems, a large portion of them are not. However, meaningful understandings of these unrecorded quality costs are important for control of product quality. Recently, a Taguchi quality loss function has been proposed in the accounting literature for estimating these hidden quality costs. This new quality loss function approach measures hidden quality costs for any variation of the actual value from the target value of a designated characteristic of a product. This paper develops various forms of quality loss functions to extend the usefulness of the Taguchi quality loss function. The various asymmetric and sensitive quality loss functions developed in this paper provide not only a meaningful tool to estimate hidden quality cost structures, but also a new way of thinking about product quality. Comprehensive examples with comparisons of results are provided to show how various quality loss functions can be used to estimate hidden quality costs for effective control of product quality. [ABSTRACT FROM AUTHOR]