• Survey Research
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• v.12 no.2
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• pp.1-26
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• 2011

Mortality for oldest-old age (aged 80 or over) in Korea has never been studied mainly due to lack of data leaving its quality aside. The rapid aging recently occurring in Korea, which no other country has never experienced, must introduce a drastic change in the structure of future population pyramid, requring a careful investigation on mortality level, pattern, and trend for the oldest-old age in Korea. For mortality trend, we need to extend the past mortality data, which has provided only an open-ended age interval 80 or 85 years and over, to age-specific mortality up to 115 years old. A prerequisite for such an extension is constructing a Korean standard mortality by which one can figure out the mortality level and pattern of the oldest-old age. A Korean standard mortality is proposed by applying one relational model and eleven functions from which we select best models for each sex in terms of three measures of fits and three consistencies of mortality. Then we extend the mortality of the open-ended age intervals by providing a method to avoid the longitudinal consistency of mortality.

• Korea journal of population studies
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• v.35 no.1
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• pp.101-130
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• 2012

This study examines mortality change in North Korea and its association with state production and welfare systems. Two main subjects are analyzed. The first theme is to examine the reliability of mortality related data released by North Korea government authorities. Examining inner consistencies among mortality related statistics and comparing with mortality trends in other socialist societies, the study finds that mortality rate was under estimated. Under-estimation of mortality by North Korean authorities is regarded to result not only from political purpose which aims to propagate the regime's superiority but also from enumeration errors of vital statistics based on the residence registration. The second theme is to estimate the change in mortality of North Korean people since the establishment of DPRK, correcting errors of mortality data. Mortality of North Korean people is estimated to have improved largely by the early 1970s, to have been sluggish hereafter, and finally to have increased during the economic hardship period between 1993 and 2008. While large people died during the food crisis in the late 1990s, however the population loss caused by mortality increase was not so great as the proposition of the huge starvation was expected. It is partly because population turbulence occurred not just by mortality increase, rather it has progressed in the joint effects of fertility decline and exodus of North Korean people for food. It is also due to North Korean people's voluntary activities of informal economy. It is also worth noting the high mortality rate of North Korean men. The high mortality of North Korean men is likely due to men's mobilization for long time in army and labor with high risk of accident and their life styles.

• Parasites, Hosts and Diseases
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• v.54 no.5
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• pp.645-652
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• 2016

Toxocara vitulorum has been rarely reported in yaks at high altitudes and remote areas of Sichuan Province of Tibetan Plateau of China. The current study was designed to investigate the prevalence, associated risk factors, and phylogenetic characteristics of T. vitulorum in yak calves on the Qinghai Tibetan plateau. Fecal samples were collected from 891 yak calves and were examined for the presence of T. vitulorum eggs by the McMaster technique. A multivariable logistic regression model was employed to explore variables potentially associated with exposure to T. vitulorum infection. T. vitulorum specimens were collected from the feces of yaks in Hongyuan of Sichuan Province, China. DNA was extracted from ascaris. After PCR amplification, the sequencing of ND1 gene was carried out and phylogenetic analyses was performed by MEGA 6.0 software. The results showed that 64 (20.1%; 95% CI 15.8-24.9%), 75 (17.2; 13.8-21.1), 29 (40.9; 29.3-53.2), and 5 (7.6; 2.5-16.8) yak calves were detected out to excrete T. vitulorum eggs in yak calve feces in Qinghai, Tibet, Sichuan, and Gansu, respectively. The present study revealed that high infection and mortality by T. vitulorum is wildly spread on the Qinghai Tibetan plateau, China by fecal examination. Geographical origin, ages, and fecal consistencies are the risk factors associated with T. vitulorum prevalence by logistic regression analysis. Molecular detection and phylogenetic analysis of ND1 gene of T. vitulorum indicated that T. vitulorum in the yak calves on the Qinghai Tibetan plateau are homologous to preveiously studies reported.