As astroviral infection rapidly increased in the summer of 2022 in Korea, this study aimed to determine the cause and genotype of astroviruses during this period. From January to December 2022, we tested 43,312 stool samples from patients with acute gastroenteritis utilizing multiplex PCR to detect HAstV. For the HAstV-positive samples, we determined the genotypes of the HAstVs by PCR and sequencing. The monthly positive rate from 2015 to 2022 showed a notable and abrupt increase of HAstV infection between June and August 2022, peaking at 9.8% in July 2022. The annual positivity rate of HAstV remained at 2–3% between 2015 and 2019, and then decreased to 0.5% in 2020, followed by an increase to 1.5% in 2021 and 3.6% in 2022.The genotyped astroviruses in 2022 were all identified as HAstV-1 type, and the nucleotide identity% among them was >99%. The GenBank accession number for the strain genetically closest to the strains identified in our study was ON571597.1, which was HAstV-1 isolated from Pingtan in 2019. Our results provide recent epidemiological data on HAstVs in Korea. The decline and surge in astrovirus positivity in recent years may be related to the COVID-19 pandemic.

Reintroduction includes the captive propagation and movement of extirpated animals or plants into areas of historical and native distribution. Many biotic or abiotic factors can affect a founder population when small numbers are released into unfamiliar novel environments, particularly at the early stage of reintroduction. The inclusion of behavioural and ecological components plays a crucial role in the decision-making process of endangered species conservation efforts such as reintroduction. Since the resident population of Oriental Storks Ciconia boyciana was locally extirpated in South Korea in 1971, its founders have been established through reintroduction since 2015. The aim of this study was to investigate the demography, habitat use, and movement patterns of stork founders using the first two-year demographic and tracking data. Stork founders maintained their population size, which slightly increased in the long term. The patterns of habitat use and movement depended on rice paddy fields for foraging and breeding along with mixed effects of breeding status and season. Considering ecological and life history-related perspectives, we also discuss the potential adaptiveness of founder Oriental Storks as a resident population in a novel environment in South Korea.

Research on attitudes toward immigrants and refugees largely focuses on intergroup conflict and related threats imposed by outgroup members. This study shifts the analytic focus to intragroup conflict: a domestic struggle among natives over how to handle recently arrived refugees and on their perception of foreign workers in general and Muslims in particular. By exploiting an exogenous variation in the interview timing of a nationally representative survey conducted in South Korea, a “new immigration destination,” this study offers a causal estimate (local average treatment effect) of domestic societal conflict on outgroup attitudes. Results from regression discontinuity (RD) analysis show that in its aftermath—immediately following the completion of a controversial e-petition sponsored by the anti-refugee group demanding that the government extradite asylum seekers—the public opinion of Korean adults toward foreign workers and Muslims became more, not less, favorable. Heterogeneous treatment effects are also found across two respondent-level characteristics: cosmopolitan identity and relative deprivation. Specifically, the focal relationship is more pronounced among individuals who identify less with cosmopolitan citizenship and among those who are more relatively deprived.

Objectives: The treatment of infected knee arthritis in patients with coexisting joint destruction, including superimposed advanced arthritis or chronic osteomyelitis, is challenging. We investigated the outcomes of 2-stage primary total knee arthroplasty (TKA) for evolutive infected arthritis with coexistent joint destruction. Methods: We retrospectively reviewed the cases of 50 patients from 5 hospitals who presented with infected arthritis of the knee and were treated with 2-stage TKA: debridement and antibiotic-loaded articulating cement spacer (ALCS) insertion as the first stage and TKA as the second stage. We recorded demographics, laboratory results, and radiographic findings including Kellgren-Lawrence classification (KL) for knee arthritis. Outcomes including infection eradication, knee range of motion (ROM), and patient-reported outcome measures were evaluated. Results: The patient cohort had a mean age of 71.8 years (range, 40–86); they were followed for an average of 4.1 years (range, 2.2–13.3). Also, 40 patients showed KL grade 4, whereas 10 patients showed grade 3. A pathogen was identified in 38 cases (73.1%); methicillin-resistant staphylococci infections (N = 16) and Candida spp infections (N = 7) were the 2 most common types. Constrained prostheses were used in 10 cases (20%). Stem augmentations were used in 15 cases (36.0%) and block augmentations were used in 8 cases (19.0%). One patient had recurrent infection after TKA, so the eradication rate was 98%. After 2-stage TKA, the mean knee ROM was 119.4° (range, 80°–140°) and the mean Knee Society (KS) knee score was 90.4, the average KS function score was 84.7, the average Hospital for Special Surgery (HSS) score was 87.2, and the average Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) score was 16.7. The KS function scores (P = .029) and the WOMAC scores (P = .022) were significantly better in 17 patients who underwent ALCS insertion within 30 days of infection diagnosis compared to the other 33 patients. Conclusions: The 2-stage primary TKA for patients with infected knee arthritis with coexisting joint destruction showed satisfactory outcomes with a low infection recurrence. However, constrained prostheses or augmentation use may be necessary. Notably, some functional scores were better in the group that underwent ALCS insertion relatively early after the infection diagnosis.

This article examines the impact of extreme weather on dairy farm productivity in the northeastern U.S., accounting for the effects of extreme temperatures on dairy cow productivity and on feed production—the predominant feeding system in the region. Using a stochastic frontier production model and 2010–20 dairy farm-level data, we find that although heat stress impacts cow productivity negatively, it increases feed production. No discernable impacts of extreme cold temperatures were found. Additional results indicate the presence of significant labor-augmenting productivity and that larger farms experience larger productivity growth thanks to increasing returns to scale and allocative efficiency.

Most research on attitudes towards immigrants and immigration problematically conflates the documented and the undocumented. Previous studies also largely ignore the autonomous role of population density. Based on data drawn from two nationally representative surveys, this paper focuses on contemporary American attitudes towards undocumented immigration and immigrants. Contra the dominant view, we find that education and income have no effect. More important, population density, measured at the county level, significantly predicts favorable attitudes, controlling for factors often erroneously conflated with density: race, income, education, political affiliation, age, gender, and interaction with immigrants. In fact, interaction tends to decrease favorable attitudes. We explain these findings by proposing a novel account of cosmopolitanism, using favorable attitudes towards undocumented immigrants and immigration as an empirical indicator. Those who live in places with higher density are more used to see and be seen in everyday life by countless people with whom they share the same spaces without necessarily interacting with them. As a result, they are more likely to consider all them, including undocumented immigrants, in a superficial yet egalitarian way as generalized others to be ignored. It is this tolerance based on general indifference that is the basis of cosmopolitanism.

Cosmopolitan habitat-forming taxa of algae such as the genus Corallina provide an opportunity to compare patterns of biodiversity over wide geographic scales. Nematode assemblages inhabiting Corallina turves were compared between the south coasts of the British Isles and South Korea. A fully nested design was used with three regions in each country, two shores in each region and replicate samples taken from three patches on each shore to compare differences in the taxonomic and biological trait composition of nematode assemblages across scales. A biological traits approach, based on functional diversity of nematodes, was used to make comparisons between countries, among regions, between shores and among patches. The taxonomic and biological trait compositions of nematode assemblages were significantly different across all spatial scales (patches, shores, regions and countries). There is greater variation amongst nematode assemblages at the scale of shore than at other spatial scales. Nematode assemblage structure and functional traits are influenced by the local environmental factors on each shore including sea-surface temperature, the amount of sediment trapped in Corallina spp. and tidal range. The sea-surface temperature and the amount of sediment trapped in Corallina spp. were the predominant factors determining nematode abundance and composition of assemblages and their functional diversity.

Hospital workers are critical for a successful response to an infectious disease outbreak and for preventing disease transmission to the community. Therefore, hospital crisis management should implement efforts to improve hospital workers’ preparedness in responding to public health emergencies caused by infectious diseases. Traditionally, preparedness and skill of hospital workers have been emphasized, but awareness of the importance of the emotional mindset of hospital workers in dealing with disease outbreaks has only recently increased; therefore, empirical approaches to examining emotional responses of hospital workers has been limited. This study analyzed qualitative data of the 2015 Middle East Respiratory Syndrome outbreak in South Korea. In particular, negative emotions and stress experienced by hospital workers who treated patients were characterized, as were the events that triggered such experiences. These events were categorized into four themes (eg, Mistake, Missing, Delay Due to Communication Failure). Identifying events that trigger negative emotions in hospital workers has important implications for hospitals’ management guidance in relation to an infectious disease outbreak. (Disaster Med Public Health Preparedness. 2019;13:504-510)

A sediment core (14DH-C01) obtained from the mouth of Gomso Bay, on the west coast of South Korea, was used to obtain high-resolution palynomorph, grain-size, and 14C age data to investigate the Holocene sedimentary environment. The results indicated a transgressive depositional process with four stages controlled by sea-level change, as follows: river-dominated fluvial deposition from the early Holocene to 8.48 cal ka BP; tide-dominated tidal channel fill transgression from 8.48 to 8.08 cal ka BP; tide- to wave-dominated tidal channel fill transgression from 8.08 to 6.98 cal ka BP; and wave-dominated marine transgression from 6.98 cal ka BP to the present. Tidal channel filling was the primary mid-Holocene depositional process, accounting for the high sedimentation rate observed. The different hydrodynamics of the river-dominated, tide-dominated, tide- to wave-dominated, and wave-dominated processes following the changes in sea level may have controlled the transgressive depositional process. This transgressive sedimentary model differs from those of other large river mouth areas (e.g., the Changjiang River) since the mid-Holocene, perhaps resulting from the limited sediment supply in the study area.

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.