Analyzing Herd Behavior in Global Stock Markets: An Intercontinental Comparison

Herd behavior is an important economic phenomenon, especially in the context of the recent financial crises. In this paper, herd behavior in global stock markets is investigated with a focus on intercontinental comparison. Since most existing herd behavior indices do not provide a comparative method, we propose a new herd behavior index and demonstrate its desirable properties through simple theoretical models. As for empirical analysis, we use global stock market data from Morgan Stanley Capital International to study herd behavior especially during periods of financial crises in detail

Multiple assessment methods of prenatal exposure to radio frequency radiation from telecommunication in the Mothers and Children’s Environmental Health (MOCEH) study

Objectives: To evaluate prenatal exposure to radiofrequency radiation (RFR) from telecommunication using a mobile phone questionnaire, operator data logs of mobile phone use and a personal exposure meter (PEM). Material and Methods: The study included 1228 mother–infants pairs from the Mothers and Children’s Environmental Health (MOCEH) study – a multicenter prospective cohort study ongoing since 2006, in which participants were enrolled at ≤ 20 weeks of pregnancy, with a follow-up of a child birth and growth to assess the association between prenatal environmental exposure and children’s health. The questionnaire included the average calling frequency per day and the average calling time per day. An EME Spy 100 PEM was used to measure RFR among 269 pregnant women from November 2007 to August 2010. The operators’ log data were obtained from 21 participants. The Spearman’s correlation test was performed to evaluate correlation coefficient and 95% confidence intervals between the mobile phone use information from the questionnaire, operators’ log data, and data recorded by the PEM. Results: The operators’ log data and information from the self-reported questionnaire showed significantly high correlations in the average calling frequency per day (ρ = 0.6, p = 0.004) and average calling time per day (ρ = 0.5, p = 0.02). The correlation between information on the mobile phone use in the self-reported questionnaire and exposure index recorded by the PEM was poor. But correlation between the information of the operators’ log data and exposure index for transmission of mobile communication was significantly high: correlation coefficient (p-value) was 0.44 (0.07) for calling frequency per day, and it was 0.49 (0.04) for calling time per day. Conclusions: The questionnaire information on the mobile phone use showed moderate to high quality. Using multiple methods for exposure assessment might be better than using only one method. Int J Occup Med Environ Health 2016;29(6):959–97

Occupational Neurologic Disorders in Korea

This article presents a schematic review of the clinical manifestations of occupational neurologic disorders in Korea and discusses the toxicologic implications of these conditions. Vascular encephalopathy, parkinsonism, chronic toxic encephalopathy, cerebellar dysfunction, peripheral neuropathy, and neurodegenerative diseases are common presentations of occupational neurotoxic syndromes in Korea. Few neurotoxins cause patients to present with pathognomic neurologic syndrome. Detailed neurologic examinations and categorization of the clinical manifestations of neurologic disorders will improve the clinical management of occupational neurologic diseases. Physicians must be aware of the typical signs and symptoms of possible exposure to neurotoxins, and they should also pay attention to less-typical, rather-vague symptoms and signs in workers because the toxicologic characteristics of occupational neurologic diseases in Korea have changed from typical patterns to less-typical or equivocal patterns. This shift is likely to be due to several years of low-dose exposure, perhaps combined with the effects of aging, and new types of possibly toxicant-related neurodegenerative diseases. Close collaboration between neurologists and occupational physicians is needed to determine whether neurologic disorders are work-related

A study on the factors affecting the follow-up participation in birth cohorts

Objectives A stable follow-up participation rate is a very important factor for validity in a cohort study. This study analyzed the factors that affect the participation rate at one hospital-based birth cohort in South Korean. Methods The participants were recruited from the Mothers’ and Children’s Environmental Health study between 2006 and 2010. The analysis targeted 1751 mothers who participated in a birth cohort. We conducted analyses of general characteristics during pregnancy and those of infants at birth that affect the participation rate of the 6-month follow-up survey. Results The participation rate for the 6-month follow-up survey was 60.4%. The participation rate in the follow-up of the subsequent period decreased within a 5% to 10% range compared to the number of subjects. The participation rate of premature infants was 16.9% lower than that of a full-term infant (52.6% vs. 69.5%). Analysis showed a 16.7% difference between the participation rate of low-birthweight infants in follow-ups (53.7%) and the participation rate of infants with normal weight (70.4%). The participation rate of mothers who were employed during pregnancy was significantly lower for the 6-month follow-up compared to the participation rate of mothers who were unemployed during pregnancy. Conclusions In this study, factors such as premature birth, low-birthweight, and the employment status of the mother during pregnancy affected the participation rate of the follow-up survey for the birth cohort at six months. A specific strategy is needed to encourage survey participation for the high risk groups in the follow-ups

Multiple assessment methods of prenatal exposure to radio frequency radiation from telecommunication in the Mothers and Children’s Environmental Health (MOCEH) study

Objectives: To evaluate prenatal exposure to radiofrequency radiation (RFR) from telecommunication using a mobile phone questionnaire, operator data logs of mobile phone use and a personal exposure meter (PEM). Material and Methods: The study included 1228 mother–infants pairs from the Mothers and Children’s Environmental Health (MOCEH) study – a multicenter prospective cohort study ongoing since 2006, in which participants were enrolled at ≤ 20 weeks of pregnancy, with a follow-up of a child birth and growth to assess the association between prenatal environmental exposure and children’s health. The questionnaire included the average calling frequency per day and the average calling time per day. An EME Spy 100 PEM was used to measure RFR among 269 pregnant women from November 2007 to August 2010. The operators’ log data were obtained from 21 participants. The Spearman’s correlation test was performed to evaluate correlation coefficient and 95% confidence intervals between the mobile phone use information from the questionnaire, operators’ log data, and data recorded by the PEM. Results: The operators’ log data and information from the self-reported questionnaire showed significantly high correlations in the average calling frequency per day (ρ = 0.6, p = 0.004) and average calling time per day (ρ = 0.5, p = 0.02). The correlation between information on the mobile phone use in the self-reported questionnaire and exposure index recorded by the PEM was poor. But correlation between the information of the operators’ log data and exposure index for transmission of mobile communication was significantly high: correlation coefficient (p-value) was 0.44 (0.07) for calling frequency per day, and it was 0.49 (0.04) for calling time per day. Conclusions: The questionnaire information on the mobile phone use showed moderate to high quality. Using multiple methods for exposure assessment might be better than using only one method. Int J Occup Med Environ Health 2016;29(6):959–97

Dopamine transporter SPECT of a liver cirrhotic with atypical parkinsonism

High level of exposure to manganese (Mn) can cause a clinically and pathophysiologically distinct syndrome from idiopathic Parkinson's disease (PD). We describe the clinical features and results of [123I]-fluoropropyl (FP)-CIT SPECT of a liver cirrhotic with atypical parkinsonism. The patient developed atypical parkinsonian features associated with elevated blood Mn from hepatic dysfunction. [123I]-FP-CIT brain SPECT images of dopamine transporter (DAT) demonstrated overall normal range of DAT uptake in the striatum although there were scattered small hypodense regions. The globus pallidum had increased signal on T1-weighted magnetic resonance imaging (MRI). All these findings are compatible with those of manganism, and are remarkably different from that in PD