The Effects of Extremely Low-Frequency Magnetic Fields on Reproductive Function in Rodents

Extremely low-frequency electromagnetic fields (ELF-EMF) are defined as those having frequencies up to 300 Hz, representing a non-ionising radiation having photon energy too weak to interact with biomolecular systems. Exposure to low-frequency electric field and magnetic field (MF) generally results in negligible energy absorption in the body. However, it is well established that ELF-MF induces biologic effects in various cellular functions. ELF-MF acting as a co-inducer can potentiate weak mutagenic signalling. The concern about possible adverse effects on human health of long-term exposure to ELF-MFs, especially at frequencies of 50 or 60 Hz generated from power lines and electric devices, has been increasing. Conversely, long-term effects of chronic exposure have been excluded from the scope of the guidelines of the International Commission on Non-Ionizing Radiation Protection (ICNIRP) because of insufficient consistent scientific evidence to fix the thresholds for such possible biological effects. The results regarding the adverse effects of ELF-MF on human or animal reproductive functions are contradictory or inconclusive. Overall conclusion of epidemiologic studies on ambient residential MF exposure consistently failed to establish a link between human adverse reproductive outcomes and chronic maternal or paternal exposure to low-frequency MFs. In animal studies, there is no compelling evidence for a causal relationship between disturbed prenatal development and ELF-MF exposure. Testicular spermatogenesis progresses through a complexly regulated cellular process involving mitosis and meiosis; this process seems to be vulnerable to external stressors, such as heat, MF exposure or chemical and physical agents. Exposure to ELF-MF did significant risk impaired implantation or the foetal development in animal studies. However, there is some consistency in the increase of minor skeletal alterations in animal experiments. The evidence derived from recent studies in male mice demonstrates that ELF-MF exposure is involved with an increase in the frequency of apoptosis in spermatogenic cells. Those results suggest that exposure to MF is related to possible cytogenetic effects on testicular germ cells and therefore may negatively affect reproduction. This chapter intends to present an overview on the effects of ELF-EMF exposure on the reproductive function and a plausible mechanism in rodent species

Clinical Evaluation of Rapid Diagnostic Test Kit Using the Polysaccharide as a Genus-Specific Diagnostic Antigen for Leptospirosis in Korea, Bulgaria, and Argentina

Leptospirosis, a zoonotic disease that is caused by many serovars which are more than 200 in the world, is an emerging worldwide disease. Accurate and rapid diagnostic tests for leptospirosis are a critical step to diagnose the disease. There are some commercial kits available for diagnosis of leptospirosis, but the obscurity of a species- or genus-specific antigen of pathogenic Leptospira interrogans causes the reduced sensitivity and specificity. In this study, the polysaccharide derived from lipopolysaccharide (LPS) of nonpathogenic Leptospira biflexa serovar patoc was prepared, and the antigenicity was confirmed by immunoblot and enzyme linked immunosorbent assay (ELISA). The performance of the rapid diagnostic test (RDT) kit using the polysaccharide as a diagnostic antigen was evaluated in Korea, Bulgaria and Argentina. The sensitivity was 93.9%, 100%, and 81.0% and the specificity was 97.9%, 100%, and 95.4% in Korea (which is a rare region occurring with 2 serovars mostly), Bulgaria (epidemic region with 3 serovars chiefly) and Argentina (endemic region with 19 serovars mainly) respectively. These results indicate that this RDT is applicable for global diagnosis of leptospirosis. This rapid and effective diagnosis will be helpful for diagnosis and manage of leptospirosis to use and the polysaccharide of Leptospira may be called as genus specific antigen for diagnosis

Taxpayer’s Perception to Tax Payment in Kind System in Support of SMEs’ Sustainability: Case of the South Korean Government’s Valuation of Unlisted Stocks

In Korea, unlisted stock shares are accepted as payment for inheritance tax. In the case of insufficient cash, a taxpayer can pay the government with listed or unlisted stocks (hereinafter referred to as “tax payment in kind”). The drawback of this tax payment system is that receiving tax paid with stocks is subject to the valuation of the government and selling the stocks to an open market requires another valuation. The results of these two valuations show considerable differences, and, therefore, the selling price in the open market is very low. This study analyzes how taxpayers recognize the differences in the valuation results of these unlisted stocks and how the differences affect the pricing for repurchasing the stocks from the open market. Results show that high valuation of unlisted stocks in tax payment in kind drives buyers to lower the purchasing price in the open market. This finding implies a problem in the government’s valuation method of unlisted stocks collected as tax

Managerial Ability and Tax Planning: Trade-Off between Tax and Nontax Costs

This study aims to investigate the effects of managerial ability (MA) on the trade-off between tax and nontax costs in the sustainability perspectives of firms. An effective tax planning for corporate sustainability is to consider tax and financial reporting costs at the same time and find the optimal cost balance that exists between these two costs. MA is measured by the data envelopment analysis (DEA) frontier and Tobit regression model. DEA frontier methods can be measured by capturing the changes in market value, excluding the characteristics of firms, which are beyond management control. The interest variables of this study are tax costs, nontax costs, and the trade-off between them. This study has three main findings. First, a significantly positive relationship exists between MA and the tax cost variable. Second, a significantly negative relationship exists between MA and the nontax cost variable. Third, MA has a negative relation with the trade-off between tax and nontax costs. Therefore, this study is the first to analyze the relationship between MA and the trade-off between tax and nontax costs. This study implies that a manager should consider the trade-off between tax and nontax costs to improve the firm’s value as MA is reflected by tax and financial reporting simultaneously

Effects of Tax Incentive Policies for Land Use on Local Socioeconomic Conditions: A Case of Tax Policies for Urban Regeneration Projects in Republic of Korea

South Korea has implemented several housing urban regeneration projects (URPs) and offers various tax incentives to support these efforts. However, the reality is that there is insufficient empirical evidence to determine whether these incentives have a socioeconomic impact on URPs. The aim of this study is to examine the effects of tax incentives related to urban regeneration projects (URPTAX) on local socioeconomic factors, such as Gross Regional Domestic Product (GRDP), aging housing reduction, and housing prices. Fixed-effect models and cost–benefit analysis methods were employed in the study. The results demonstrate the following outcomes. Firstly, URPTAX positively contributes to an increase in GRDP, a decrease in the proportion of aging housing, and an increase in housing price fluctuations. However, the effectiveness of these effects varies between metropolitan and non-metropolitan areas. Therefore, this study suggests the significance of providing stronger tax incentives for housing URPs in non-metropolitan areas to encourage active projects and foster balanced regional development in South Korea

Religious Diversity of Corporate Board and Firm Value: Evidence from South Korea

When the board provides quality monitoring and advising to corporate managers, firms can achieve their goal, and so firm value increases. Board diversity is one of the issues that can affect the board effectiveness through influencing the quality of monitoring and advising. Hence, many prior studies have analyzed the effect of board diversity in various dimensions such as gender, age, race, ethnicity, education background on firm value or performance. However, prior studies do not reach out to the religious diversity of the board. So, this study investigates the relationship between religious diversity of the board and firm value. Using unique data of religion of directors for companies listed in Korea from 2008 to 2011, this study provides the following empirical results. In general, a high level of religious diversity has a positive impact on the firm value. However, when the degree of religious diversity of the board exceeds a certain point, religious diversity shows a negative relationship with the firm value. In addition, if the religion of directors is concentrated in one religion (when the level of diversity is low), firm value is lower than other control firms. The empirical finding of this study shows that religious diversity of the board matters in a similar way of other dimension of the board diversity

Extremely Low Frequency Magnetic Fields Induce Spermatogenic Germ Cell Apoptosis: Possible Mechanism

The energy generated by an extremely low frequency electromagnetic field (ELF-EMF) is too weak to directly induce genotoxicity. However, it is reported that an extremely low frequency magnetic field (ELF-MF) is related to DNA strand breakage and apoptosis. The testes that conduct spermatogenesis through a dynamic cellular process involving meiosis and mitosis seem vulnerable to external stress such as heat, MF exposure, and chemical or physical agents. Nevertheless the results regarding adverse effects of ELF-EMF on human or animal reproductive functions are inconclusive. According to the guideline of the International Commission on Non-Ionizing Radiation Protection (ICNIRP; 2010) for limiting exposure to time-varying MF (1 Hz to 100 kHz), overall conclusion of epidemiologic studies has not consistently shown an association between human adverse reproductive outcomes and maternal or paternal exposure to low frequency fields. In animal studies there is no compelling evidence of causal relationship between prenatal development and ELF-MF exposure. However there is increasing evidence that EL-EMF exposure is involved with germ cell apoptosis in testes. Biophysical mechanism by which ELF-MF induces germ cell apoptosis has not been established. This review proposes the possible mechanism of germ cell apoptosis in testes induced by ELF-MF

Deep reinforcement learning in an ultrafiltration system: Optimizing operating pressure and chemical cleaning conditions

Enhancing engineering efficiency and reducing operating costs are permanent subjects that face all engineers over the world. To effectively improve the performance of filtration systems, it is necessary to determine an optimal operating condition beyond conventional methods of periodic and empirical operation. Herein, this paper proposes an effective approach to finding an optimal operating strategy using deep reinforcement learning (DRL), particularly for an ultrafiltration (UF) system. Deep learning was developed to represent the UF system utilizing a long-short term memory and provided an environment for DRL. DRL was designed to control three actions; operating pressure, cleaning time, and cleaning concentration. Ultimately, DRL proposed the UF system to actively change the operating pressure and cleaning conditions over time toward better water productivity and operating efficiency. DRL denoted similar to 20.9% of specific energy consumption can be reduced by increasing average water flux (39.5-43.7 L m(-2) h(-1)) and reducing operating pressure (0.617-0.540 bar). Moreover, the optimal action of DRL was reasonable to achieve better performance beyond the conventional operation. Crucially, this study demonstrated that due to the nature of DRL, the approach is tractable for engineering systems that have structurally complex relationships among operating conditions and resultants