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Background: Research outcomes on intellectual development and related disabilities in North Korea are not widely known. Therefore, the current scoping review aimed to provide preliminary insight on research topics concerning intellectual disabilities in North Korea. Method: A six-stage framework for scoping review was adopted to examine research trends. Articles were categorised based on the era of supreme leader and research topic. Results: There is a greater amount of research regarding intellectual disabilities in the recent Kim Jong-un era compared to the period of the previous leader where research outcomes on general intelligence were the focus. Significant qualitative progress was similarly found. Conclusions: The current analysis on research outcomes provides meaningful insights to aid in understanding the atmosphere in North Korea surrounding intellectual disabilities. Follow-up studies and open discussions are necessary for further progress.

The vertical air pollutant concentrations and their relationships with synoptic- and local-scale air movement have been studied. This study measured the vertical profiles of PM2.5 and O3 using an unmanned aerial vehicle during summer in South Korea and analyzed the characteristics of the measured profiles. To understand the impact of synoptic air movements, we generated and categorized the 48 h air trajectories based on HYSPLIT, and we analyzed how the vertical profiles varied under different categories of long-range transport. We found that the vertical PM2.5 concentration has a positive gradient with altitude when more polluted air was transported from China or North Korea and has negative gradient when cleaner air was transported from the East Sea. Unlike PM2.5, the O3 concentration did not depend significantly on the long-range transport scenario because of the short photochemical lifetime of O3 during summer. For local-scale air movements, we found no significant impact of local wind on the measured profiles. [ABSTRACT FROM AUTHOR]

Why and how does the US provide advanced nuclear assistance to junior nuclear allies? Existing nuclear literature downplays the possibility that the US strategically employs the technical assistance option as a post-proliferation toolkit to control allied nuclear proliferation. Addressing the first question—why—I argue that the US provides advanced nuclear assistance to junior allies to inhibit the latter's growing tendency towards unilateralism after nuclear acquisition, meanwhile inducing greater allied nuclear coordination. By forging advanced nuclear partnerships, the US seeks simultaneously to draw junior allies closer to the American nuclear leadership and establish coordinated nuclear strike plans and joint nuclear targeting. Addressing the second question—how—I claim that the US provides advanced nuclear assistance at a protracted pace and in a restricted manner, calculated to exert influence over recipient junior allies for as long as possible. To provide the plausibility probe of my argument, I explore two historical cases: The US's strategic advanced nuclear assistance to the UK and to France. I conclude by identifying avenues for future study and the policy implications for China's potential response to North Korea's nuclear sophistication. [ABSTRACT FROM AUTHOR]

This article examines the relationship between US missile defense and the US-China security dilemma dynamics by developing the concept of diffuse signaling involving the Korean peninsula. We argue that the US' efforts to bolster deterrence against North Korea's growing threats through missile defense have resulted in China's countermeasures of enhancing survivability and penetrability of its second-strike capability, leading to downward spirals of tensions between Beijing and Washington. We explain how three structural factors – geography, the US alliance system, and nuclear asymmetry – have made diffuse signaling salient, thus making it very challenging for the United States to reassure China even when its actions targeted North Korea. The article empirically shows the action-reaction process through which China and the US have come to experience the aggravation of the security dilemma over the Korean peninsula. [ABSTRACT FROM AUTHOR]

Clinical performance of the Momguard non-invasive prenatal test (NIPT) was evaluated in a cohort of Korean pregnant women. The foetal trisomies 21, 18 and 13 (T21, T18 and T13) were screened by low-coverage massive parallel sequencing in the maternal blood. Among the 1011 confirmed samples, 32 cases (3.2%) had positive NIPT results. Of these positive cases, 20 cases of T21, all cases of T18 and two cases of T13 had concordant karyotype findings. Only one case out of the remaining 979 negative NIPT samples showed a false negative result. The overall sensitivity and specificity of Momguard to detect the three chromosomal aneuploidies were 96.8% and 99.8%, respectively. Momguard is a clinically useful tool for the detection of T21, T18 and T13 in singleton pregnancy. However, as other NIPT tests, it carries the risk of false positive and false negative results. Hence, the genetic counsellors should provide these limitations to the examinees.Impact StatementWhat is already known on this subject? The NIPT approach using massive parallel sequencing (MPS) showed high sensitivity and specificity in various clinical studies. These results are based on analysis systems using their own bioinformatics algorithms.What the results of this study add? When this NIPT technology was introduced in Korea, the first biological specimens collected in Korea were transported overseas for processing in overseas laboratories and analysed by other country's analysis methods. We needed our own NIPT algorithm and developed Momguard NIPT for the first time in Korea. This study attempted to evaluate this Momguard NIPT protocol prospectively in a large number of samples obtained from three Korean hospitals.What the implications are of these findings for clinical practice and/or further research? The overall sensitivity and specificity to identify T13, T18 and T21 were 96.8% and 99.8%, respectively. These accuracy values were comparable to that of other studies. From this study, we found that Momguard is a clinically useful tool for the detection of three chromosomal aneuploidies. However, as other NIPT tests, it carries the risk of false positive and false negative results. Hence, the genetic counsellors should provide these limitations to the examinees. [ABSTRACT FROM AUTHOR]

• The titer of a PR8-derived clade 2·3·4·4a H5N8 virus in chicken embryo was very low. • H103Y mutation in HA increased virus titer in chicken embryo and thermo-stability. • H103Y mutation increased mammalian pathogenicity of the virus as reported. • Replacement of PR8 and a prototypic PB2 genes removed the pathogenicity. • The safe and productive virus protected chickens from fatal H5N6 virus challenge. The clade 2·3·4·4 H5Nx is a highly pathogenic avian influenza (HPAI) virus, which first appeared in China and has spread worldwide since then, including Korea. It is divided into subclades a - d, but the PR8-derived recombinant clade 2·3·4·4 a viruses replicate inefficiently in embryonated chicken eggs (ECEs). High virus titer in ECEs and no mammalian pathogenicity are the most important prerequisites of efficacious and safer vaccine strains against HPAI. In this study, we have synthesized hemagglutinin (HA) and neuraminidase (NA) genes based on the consensus amino acid sequences of the clade 2·3·4·4a and b H5N8 HPAIVs, using the GISAID database. We generated PR8-derived H5N8 recombinant viruses with single point mutations in HA and NA, which are related to efficient replication in ECEs. The H103Y mutation in HA increased mammalian pathogenicity as well as virus titer in ECEs, by 10-fold. We also successfully eradicated mammalian pathogenicity in H103Y-bearing H5N8 recombinant virus by exchanging PB2 genes of PR8 and 01310 (Korean H9N2 vaccine strain). The final optimized H5N8 vaccine strain completely protected against a heterologous clade 2·3·4·4c H5N6 HPAIV in chickens, and induced hemagglutination inhibition (HI) antibody in ducks. However, the antibody titer of ducks showed age-dependent results. Thus, H103Y and 01310PB2 gene have been successfully applied to generate a highly productive, safe, and efficacious clade 2·3·4·4 H5N8 vaccine strain in ECEs. [ABSTRACT FROM AUTHOR]

Background: The problem that is central to trauma research is the prediction of survival rate after trauma. Trauma and Injury Severity Score is being used for predicting survival rate after trauma. Many countries have conducted a study on the classification, characteristics of variables, and the validity of the Trauma and Injury Severity Score model. However, few investigations have been made on the characteristics of coefficients or variables related to Trauma and Injury Severity Score in Korea. Objectives: There is a need for coefficient analysis of Trauma and Injury Severity Score which was created based on the United States database to be optimized for the situation in Korea. Methods: This study examined how the currently used Trauma and Injury Severity Score coefficients were developed and created for trauma patients visiting the emergency department in a hospital in Korea using the analytical method. A total of 34,340 trauma patients who were hospitalized into an emergency center from January 2012 to December 2014 for 3 years were analyzed with trauma registry established on August 2006. Results: Trauma and Injury Severity Score coefficients were transformed with the methods that were used to make the existing Trauma and Injury Severity Score coefficients using the trauma patients' data. Regression coefficients (B) were drawn by building up a logistic regression analysis model that used variables such as Injury Severity Score, Revised Trauma Score, and age depending on survival with Trauma and Injury Severity Score. Conclusion: With regard to Trauma and Injury Severity Score established in the United States differing from Korea in injury types, it seems possible to realize significant survival rate by deriving coefficients with data in Korea and reanalyzing them. [ABSTRACT FROM AUTHOR]

Background: Vivax malaria was successfully eliminated in the Republic of Korea (South Korea) in the late 1970s, but it was found to have re-emerged from 1993. In order to control malaria and evaluate the effectiveness of malaria controls, it is important to develop a spatiotemporal understanding of the genetic structure of the parasite population. Here, we estimated the population structure and temporal dynamics of the transmission of Plasmodium vivax in South Korea by analyzing microsatellite DNA markers of the parasite. Methodology/Principal Findings: We analyzed 14 microsatellite DNA loci of the P. vivax genome from 163 South Korean isolates collected from 1994 to 2008. Allelic data were used to analyze linkage disequilibrium (LD), genetic differentiation and population structure, in order to make a detailed estimate of temporal change in the parasite population. The LD analysis showed a gradual decrease in LD levels, while the levels of genetic differentiation between successive years and analysis of the population structure based on the Bayesian approach suggested that a drastic genetic change occurred in the South Korean population during 2002 and 2003. Conclusions/Significance: Although relapse and asymptomatic parasite carriage might influence the population structure to some extent, our results suggested the continual introduction of P. vivax into South Korea through other parasite population sources. One possible source, particularly during 2002 and 2003, is North Korea. Molecular epidemiology using microsatellite DNA of the P. vivax population is effective for assessing the population structure and temporal dynamics of parasite transmission; information that can assist in the elimination of vivax malaria in endemic areas. Author Summary: Vivax malaria is widely prevalent, predominantly in Asia and South America. There were 390 million cases reported in 2009. Worldwide, in the same year, 2.85 billion people were at risk of infection. Plasmodium vivax is not limited to tropical and subtropical regions; it also appears in temperate areas. We previously examined the characteristics of P. vivax in South Korea, a temperate area, temporally, using 10 microsatellite DNA (a short tandem repeat DNA sequence) in the parasite genome and found the population to have low genetic diversity and a low recombination rate in comparison to tropical areas. In the present study, we examine the successive changes of the South Korean populations from 1994 to 2008, and the reasons for the lack of success in eliminating vivax malaria in this country. We found that, in spite of a low recombination rate, outbreeding between different genotypes seemed to increase gradually, and that the genetic composition of the population drastically changed during 2002 and 2003. This suggests that the parasite is continually introduced from other populations, probably from North Korea. The present study also demonstrated the utility of polymorphic DNA markers of P. vivax for the estimation of the transmission situation in endemic areas. [ABSTRACT FROM AUTHOR]

• Improved identification of bone remains was achieved by combining high-throughput SNP typing with conventional genetic analysis. • Advantages of SNP analysis were presented in terms of typing performance in degraded samples and resolution of ambiguous STR results. • Kinship analysis of SNP data using a software program was efficient in large-scale forensic identification. • SNPs can be used as complementary markers in large-scale DNA analysis for further investigation. Single nucleotide polymorphisms (SNPs) are valuable markers complementary to conventional forensic short tandem repeat (STR) markers in genetic typing, with potential advantages in challenging forensic casework. With the advent of high-throughput technologies, such as microarrays and massively parallel sequencing, the use of SNP typing has now expanded to large-scale forensic applications. Herein, a forensic case is presented to demonstrate the usefulness of SNP typing in identifying large-scale human bone remains with reference database construction. A total of 402 bone remains were recovered from an island in the Jeju Province of Korea where a massive disaster occurred in 1948. The first phase of the identification process was accomplished via conventional DNA typing methods including autosomal and Y-chromosomal STR typing, and mitochondrial DNA sequencing, which resulted in the identification of 74 of 402 remains. The second phase of the identification involved the remaining 327 unidentified remains using SNP typing as a supplementary tool based on Affymetrix resequencing array. The SNP markers of 782 family members were also analyzed and a reference database was constructed for comparison. An additional 51 bone remains were identified in the second phase. SNP data obtained from the supplementary genotyping yielded additional genetic information as well as contributed to kinship testing to determine the second degrees of relationship. In addition SNPs are useful in discriminating ambiguous relationship when only STR data are available. A software program developed for SNP typing system enabled efficient kinship analysis for large-scale forensic identification. The results and the casework are described and discussed. [ABSTRACT FROM AUTHOR]

Liriope platyphylla (Liliaceae), a medical plant distributed mainly in China, Taiwan, and Korea, has been used traditionally for the treatment of cough, sputum, asthma, and neurodegenerative diseases. The present study involved the metabolic profiling of this plant and reports spicatoside A accumulation in four different varieties of L. platyphylla (Cheongyangjaerae, Seongsoo, Cheongsim, and Liriope Tuber No. 1) using HPLC and gas chromatography time-of-flight mass spectrometry (GC–TOFMS). A total of 47 metabolites were detected in the different cultivars using GC–TOFMS-based metabolic profiling. The resulting data were subjected to principal component analysis (PCA) for determining the whole experimental variation, and the different cultivars were separated by score plots. Furthermore, hierarchical clustering, Pearson's correlation, and partial least-squares discriminant analyses (PLS-DA) were subsequently performed to determine significant differences in the various metabolites of the cultivars. The HPLC data revealed that the presence of spicatoside A was detected in all four cultivars, with the amount of spicatoside A varying among them. Among the cultivars, Liriope Tuber No. 1 contained the highest amount of spicatoside A (1.83 ± 0.13 mg/g dry weight), followed by Cheongyangjaerae (1.25 ± 0.01 mg/g dry weight), Cheongsim (1.09 ± 0.04 mg/g dry weight), and Seongsoo (1.01 ± 0.02 mg/g dry weight). The identification of spicatoside A was confirmed by comparing the retention time of the sample with the retention time of the standard. Moreover, the Cheongsim cultivar contained higher levels of phenolic compounds—including vanillic acid, quinic acid, gallic acid, chlorogenic acid, caffeic acid, and benzoic acid—than those of the other two cultivars. On the other hand, the levels of amino acids were higher in the Seongsoo cultivar. Therefore, this study may help breeders produce new varieties with improved nutraceutical and nutritional qualities. [ABSTRACT FROM AUTHOR]

Objective: This study aimed to elucidate the relationships among sleep quality, subjective cognitive decline (SCD), and SCD-related functional limitation.Methods: The present study used the 2018 Korea Community Health Survey (KCHS) data, which comprise community-based, nationwide representative data collected by the Korea Centers for Disease Control and Prevention. Sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI). The study population comprised 203,082 persons aged ≥ 19 years.Results: Among 203,082 subjects, 35,892 (17.7%) had SCD and 4,373 (2.2%) had SCD-related functional limitation. Individuals with poor sleep quality (PSQI > 5) were approximately 2-fold more likely to exhibit SCD and SCD-related functional limitation (SCD: Odds ratio [OR] = 1.983, 95% confidence interval [CI] = 1.915-2.054; SCD-related functional limitation: OR = 2.405, 95% CI = 2.158-2.681). Moreover, younger adults showed a greater influence of sleep quality on SCD and SCD-related functional limitation, compared to older adults.Limitations: Because this study used cross-sectional data, it could not establish a causal relationship among poor sleep quality, SCD, and SCD-related functional limitation.Conclusions: Poor sleep quality might contribute to cognitive and functional decline. The present study showed that, in both younger and older adults, there is a need to identify early stages of cognitive decline (e.g., SCD), as well as to perform intervention to prevent poor sleep quality and cognitive decline. [ABSTRACT FROM AUTHOR]

We have investigated the suitability of phosphate addition, in the form MH 2 PO 4 (M = Na+, K+ or NH 4 +), for the selective removal of uranium from a complex waste effluent. The effluent in question is generated as part of a treatment strategy for a spent uranium catalyst, used in the production of acrylonitrile (Sohio process), which has been in temporary storage in Korea since 2004. Both pH (3.0–11.0) and phosphate dosages (0.25–10 mM) have been screened to identify the optimal conditions of 6.25 and 1 mM, respectively, for an initial uranium concentration of 0.16 mM. Precipitation kinetics have been investigated revealing the rapid removal of uranium from solution, with 30 min found to be optimal. The effluent was effectively decontaminated via Meta-ankoleite (K(UO 2)(PO 4)·3H 2 O) formation to uranium levels below the Korean release limit of 1 ppm for uranium-bearing liquid wastes, with KH 2 PO 4 addition being chosen for the real process. Final decontamination factors of the order of ≥ 8000 were readily achieved. Aluminium, calcium and iron containing coagulants were screened for the clean-up of the remaining supernatant, post-uranium removal, ensuring the final effluent meets the relevant release criteria (pH, total suspended solids, total phosphate and turbidity) for general, non-radioactive, effluents. A process scheme is presented and discussed for adaptation to similar uranium containing effluents. Image 1 • Rapid uranium removal from industrial effluent via phosphate addition. • Large decontamination factor and volume reduction. • Bench scale process verification. • Process flow sheet presented for adaptation to other uranium containing effluents. [ABSTRACT FROM AUTHOR]