We report on the X-ray diffraction data and unit-cell parameters of Mn4C, which has a cubic perovskite-type structure with a = 3.8726 Å and unit-cell volume V = 58.1 Å3. The measured lines were indexed and are consistent with the space group $ Pm { \bar {\it 3}} m$ (No. 221).

We have optimized the input pulse width and injection time to achieve the highest possible output pulse energy in a double-pass laser amplifier using two Nd:YAG rods. For this purpose, we have extended the Frantz–Nodvik equation by simultaneously including both spontaneous emission and pump energy variation. The effective pump energy of the flash lamp was 8.84 J for each gain medium. The energy of 1 J could be amplified to an output energy of 12.17 J with the maximum achieved extraction efficiency of 63.18% when an input pulse having a pulse width of 168  $\unicode[STIX]{x03BC}$ s is sent 10  $\unicode[STIX]{x03BC}$ s after the absorbed pump energy becomes the maximum value.

The status of Asian populations of the Eurasian otter Lutra lutra is largely unknown. Since its designation as a Natural Monument (in 1983) and as Endangered (in 1997) in South Korea the authorities there have been trying to conserve and recover the species. We conducted a national otter survey by standard methods in 2017 and compared the current otter distribution to those recorded in a previous survey (2010). We found otter signs in 84.5% of 1,105 10 × 10 km grid cells, with the highest sprainting intensity in the south-west in the Yeongsan River Basin and on the south coast, where we recorded 7.05 and 6.26 spraints/site, respectively. Despite relatively low spraint densities, the otter has expanded its range since 2010 by colonizing urban areas. This trend suggests that South Korea could be a source area for the recovery of the Eurasian otter in East Asia.

The submarine channel-fill system of the Cambrian Spurs Formation exhibits unique metre-scale cycles of breccia and diamictite. The studied sections, Eureka Spurs, are located at the Mariner Glacier in the central-eastern part of northern Victoria Land, Antarctica. A facies analysis of the channel-fill deposit has led to the recognition of four main lithofacies: breccia, diamictite, thin-bedded sandstone and mudstone. The channel-fill deposit consists of two architectural elements: hollow-fill (HF) and sheet-like (SL) elements. The SL has wide convex-up geometry and consists solely of a very thick bed of diamictite, and is interpreted as a submarine channel lobe. The HF has a concave-up erosional base and flat upper surface. The HF consists of nine cyclic alternations of underlying breccia (cohesionless debris flow) and overlying diamictite (cohesive debris flow). The deposition of breccia is interpreted to have been controlled by repeated allogenic processes such as earthquakes. In contrast, the abrupt vertical transition from breccia to diamictite in each cycle is interpreted to have resulted from an autogenic, slope instability-related process. The interaction of the allogenic and autogenic factors recorded in the metre-scale unique cyclic deposits provides new criteria to interpret cycles of submarine debris flow.

Two challenges exist in laser-assisted atom probe tomography (APT). First, a drastic decline in mass-resolving power is caused, not only by laser-induced thermal effects on the APT tips of bulk oxide materials, but also the associated asymmetric evaporation behavior; second, the field evaporation mechanisms of bulk oxide tips under laser illumination are still unclear due to the complex relations between laser pulse and oxide materials. In this study, both phenomena were investigated by depositing Ni- and Co-capping layers onto the bulk LaAlO3 tips, and using stepwise APT analysis with transmission electron microscopy (TEM) observation of the tip shapes. By employing the metallic capping, the heating at the surface of the oxide tips during APT analysis became more symmetrical, thereby enabling a high mass-resolving power in the mass spectrum. In addition, the stepwise microscopy technique visualized tip shape evolution during APT analysis, thereby accounting for evaporation sequences at the tip surface. The combination of “capping” and “stepwise APT with TEM,” is applicable to any nonconductors; it provides a direct observation of tip shape evolution, allows determination of the field evaporation strength of oxides, and facilitates understanding of the effects of ultrafast laser illumination on an oxide tip.

Shumardiid trilobites had a small, unique morphology, and formed a key constituent in trilobite faunas during the Cambrian–Ordovician. Because of their unusual morphology, they have been the subject of research s, into various aspects such as their life habit, functional morphology, evolutionary origin and ontogeny. Originally, a flat, adult-like protaspid morphology was suggested for shumardiids, but subsequently a bulbous protaspid morphology interpreted to be associated with metamorphosis was also suggested for this unique trilobite group. This article documents the ontogeny of the two co-occurring shumardiid trilobites, Akoldinioidia latus Park and Kihm and Koldinioidia choii Park and Kihm, from the middle Furongian Hwajeol Formation, Taebaeksan Basin, Korea. Interestingly, protaspides of the two shumardiids have a bulbous morphology. Given the stratigraphic occurrences of the two shumardiids, it can be inferred that commutavi protaspis appeared quite early in the shumardiid evolution. The co-occurrence of the two closely related trilobites is reminiscent of sexual dimorphism, although further evidence is required to prove it. The appearance of metamorphosis-undergoing protaspides in the Furongian shumardiids may have been due to the onset of increasing ecological pressure in the early phase of the Great Ordovician Biodiversification Event.

This study aimed to investigate the relationship between the unemployment experience and depressive symptoms among mid-aged (ages 45–59) and elderly (ages 60 or above) persons and to examine further the effects of unemployment insurance, industrial accident compensation insurance (IACI) and national pension on the stated relationship. Data were used from the Korean Longitudinal Study of Aging (KLoSA) between 2006 and 2012. A total of 1,536 individuals employed at the 2006 baseline were followed. The association between employment status change during 2006 to 2008, 2008 to 2010 or 2010 to 2012 and depressive symptoms in years 2008, 2010 or 2012 were analysed using a generalised estimating equation model. Depressive symptoms were measured with the Center for Epidemiological Studies Depression Scale (CES-D 10) scale. The results showed that the ‘employed to unemployed’ group had statistically significant increases in depression scores in the mid-aged (β = 0.4884, p = 0.0038) and elderly (β = 0.8275, p ⩽ 0.0001) categories, compared to the ‘employed to employed’ group. Findings were maintained in groups without a social safety net. Contrastingly, the ‘employed to unemployed’ groups with unemployment insurance and IACI did not show statistically significant increases in depression scores. The ‘employed to unemployed’ category of individuals enrolled in the national pension system exhibited a lower increase of depression. Therefore, an enhanced focus on the mental health of unemployed individuals is required, in addition to the provision of a reliable social safety net.

Echinochloa species are among the most troublesome weeds in rice cultivation, and grow in a broad habitat range in Korea. Although various ecotypes of Echinochloa have been collected as germplasm for future studies, it has been difficult to classify them due to their high level of morphological similarity. This study was thus conducted to develop and investigate the phylogenetic relationships between 77 Echinochloa accessions with the use of 23 simple sequence repeat (SSR) markers and 24 morphological traits. Of 77 Echinochloa accessions, including 57 accessions from Korea and 5 reference species, late watergrass was clearly clustered as a distinctive group from barnyardgrass and other Echinochloa species. In this analysis, we also identified core genetic and morphological markers that can be used for the future identification and classification of Echinochloa species. Five out of 23 SSR makers produced distinctive bands that discriminate late watergrass from barnyardgrass and other Echinochloa species. Four morphological traits of the reproductive organs were the most influential contributors for classifying Echinochloa species. Although there was no clear consensus generated in this study between SSR markers and morphological trait analyses, our results support the potential use of the selected SSR markers and morphological traits in future studies of Echinochloa.

Because it is inevitable to lose some information in the process of one dimensional luminosity profile extraction, we developed a two dimensional luminosity decomposition method in order to examine the structure of galaxy such as bulge, bar and spiral arms.

Background: Dysphagia is a common symptom and an important prognostic factor in Parkinson’s disease (PD). Although cognitive and motor dysfunctions may contribute to dysphagia in patients with PD, any specific association between such problems and swallowing functions is unclear. Here, we examined the potential relationship between cognitive/motor components and swallowing functions in PD. We evaluated the contributions of cognition and motor function to the components of swallowing via video fluoroscopic swallowing (VFS) experiments. Methods: We prospectively enrolled 56 patients without dementia having PD. Parkinson’s disease severity was assessed by the Unified Parkinson’s Disease Rating Scale (UPDRS). All participants received neuropsychological tests covering general mental status, visuospatial function, attention, language, learning and memory, and frontal executive function. The well-validated “modified barium swallow impairment profile” scoring system was applied during VFS studies to quantify swallowing impairments. Finally, correlations between neuropsychological or motor functions and impairment in swallowing components were calculated. Results: The most significant correlations were found between the frontal/executive or learning/memory domains and the oral phase of swallowing, though a minor component of the pharyngeal phase correlated with frontal function as well. Bradykinesia and the UPDRS total score were associated with both the pharyngeal and oral phases. Conclusions: Our findings suggest that cognitive dysfunctions are associated with the oral phase of swallowing in patients with early stage PD while the severity of motor symptoms may be associated with overall swallowing function.

Korea Astronomy and Space Science Institute (KASI) successfully completed the development of Korea Microlensing Telescope Network (KMTNet, Park et al. 2012) in mid-2015, following which it conducted test runs for several months. ‘DEep Ecliptic Patrol of the Southern sky’ (DEEP-South, Moon et al. 2015), which will be used for asteroid and comet studies, will not only characterize targeted asteroids, carrying out blind surveys toward the sweet spots, but will also mine the data of such bodies using the KMTNet archive. We report preliminary lightcurves of four Potentially Hazardous Asteroids (PHAs) from test runs at KMTNet-CTIO in the February - May 2015 period.