Usage-based approaches to language acquisition explain language development as a gradual process of generalizing constructions through language experience. This study investigated second language learners’ development of constructional knowledge from the perspective of usage-based language development. A total of 169 Korean EFL students at five grade levels completed a sentence-sorting and a translation task. Results of the sorting task showed stronger constructional sorting as the learners’ grade level increased. Additionally, the sorting of intermediate-level learners was influenced by verb semantics such that the sentences including light verbs were more strongly clustered according to constructions than the sentences with heavy verbs, suggesting learners’ reliance on light verbs in the early stages of constructional development. Results of the translation task demonstrated a higher translation accuracy with increasing proficiency, but with a significant amount of variation across individual constructions contingent on the constructions’ syntactic and semantic complexity. Overall, our findings confirm the usage-based development of L2 learning.

We perform density functional theory calculations to study the CO and O2 adsorption chemistry of Pt@X core@shell bimetallic nanoparticles (X = Pd, Rh, Ru, Au, or Ag). To prevent CO-poisoning of Pt nanoparticles, we introduce a Pt@X core-shell nanoparticle model that is composed of exposed surface sites of Pt and facets of X alloying element. We find that Pt@Pd, Pt@Rh, Pt@Ru, and Pt@Ag nanoparticles spatially bind CO and O2, separately, on Pt and X, respectively. Particularly, Pt@Ag nanoparticles show the most well-balanced CO and O2 binding energy values, which are required for facile CO oxidation. On the other hand, the O2 binding energies of Pt@Pd, Pt@Ru, and Pt@Rh nanoparticles are too strong to catalyze further CO oxidation because of the strong oxygen affinity of Pd, Ru, and Rh. The Au shell of Pt@Au nanoparticles preferentially bond CO rather than O2. From a catalysis design perspective, we believe that Pt@Ag is a better-performing Ptbased CO-tolerant CO oxidation catalyst.

West Nile Virus (WNV) is transmitted by infected mosquitoes. Vector mosquitoes usually acquire these pathogens fromfeeding on an infected host, and transmit the pathogens to a naive host during feeding events. To understand the virustransmission dynamics and to survey WNV throughout country, the present study has been conducted. We collected mosquitoesat urban parks in Seongnam, Wonju, Gunsan, Daegu, and Tongyeong using CDC light trap with Dry ice from April toSeptemper in 2017 (mosquito collecting is on going). Among collected mosquitoes, blood-fed mosquitoes were conductedblood meal identification assay and the other mosquitoes were subjected to virus detection using real-time PCR method.A total of 2,290 mosquitoes representing 6 genera and 15 species were collected. The most dominant species was Culexpipiens complex (42.1%) followed by Aedes albopictus (15.1%), Ae. vexans nipponii (14.6%), Ochlerotatus koreicus (9.8%),Cx. orientalis (6.5%), and Armigeres subalbatus (4.4%). The blood meal source were of mammal (93.3%), and birds (6.7%).So far, no WNV has been detected in any mosquitoes.

Through density functional theory calculations, to provide insight into the origins of the catalytic activity of Au nanoparticles (NPs) toward oxidation reactions, we have scrutinized the oxygen adsorption chemistry of 9 types of small unsupported Au NPs of around 1 nm in size (Au13, Au19, Au20, Au25, Au38, and Au55) looking at several factors (size, shape, and coordination number). We found that these NPs, except for the icosahedral Au13, do not strongly bind to O2 molecules. Energetically most feasible O2 adsorption that potentially provides high CO oxidation activity is observed in the icosahedral Au13, our smallest Au NP. In spite of the chemical inertness of bulk Au, the structural fluxionality of such very small Au NP enables strong O2 adsorption. Our results can support recent experimental findings that the exceptional catalytic activity of Au NPs comes from very small Au species consisting of around 10 atoms each.

West Nile Virus (WNV) is transmitted by infected mosquitoes. Vector mosquitoes usually acquire these pathogens from feeding on an infected host, and transmit the pathogens to a naive host during feeding events. To understand the virus transmission dynamics and to survey WNV throughout country, the present study has been conducted. We collected mosquitoes in Jeju, Busan, Gunsan, and Incheon using CDC light trap and BG Sentinel trap from April to October in 2016. Among collected mosquitoes, blood-fed mosquitoes were conducted blood meal identification assay and the other mosquitoes were subjected to virus detection using real-time PCR method. A total of 29,603 mosquitoes representing 8 genera and 19 species were collected. The most dominant species was Culex pippins complex (35.0%) followed by Cx. bitaeniorhynchus (12.2%), Armigeres subalbatus (11.2%), Aedes albopictus (10.8%), Ae. vexans nipponii (10.3%), and Ochlerotatus dorsalis (8.4%). The blood meal source were of mammal (70.4%), birds (29.0%) and amphibian (0.6%). WNV was not detected in any mosquitoes.

West Nile Fever is one of most serious disease spreading throughout world since 1990. West Nile Virus (WNV) is transmitted by infected mosquitoes. The possibility of overseas inflow of this virus seems to be high in Korea. To know the WNV infection of mosquitoes, we collected mosquitoes in Jeju, Busan, Gunsan, and Incheon using CDC light trap and BG Sentinel trap from April to August in 2016. Collected mosquitoes were conducted virus detection using real-time PCR method. A total of 22,632 mosquitoes representing 9 genera and 18 species were collected. The most dominant species was Culex pippins complex (36%) followed by Aedes vexans (13%), Ae. albopictus (10%) and Ochlerotatus koreicus (10%). WNV was not detected in any mosquitoes until now.

There are over 3,000 different species of mosquitoes throughout the world; currently 56 species are reported in Korea. Mosquitoes can act as vectors for many disease-causing viruses and parasites during blood sucking. Various species of mosquitoes are estimated to transmit various types of disease to more than 700 million people annually in Africa, South America, Central America, Mexico, Russia, and much of Asia, with millions of resultant deaths. At least two million people annually die of these diseases, and the morbidity rates are many times higher still. To prevent the spread of diseases, KNIH (Korea National Institute of Health) used three categorized methods; identifying or taxonomic analysis of mosquitoes, detecting virus caring mosquitoes, and detecting malaria from Anopheline mosquitoes. We have proved that taxonomic analysis using DNA barcording method (COI gene) is useful to complement identification of mosquito species. In detecting virus, we have reported Cx. orientalis as a new potential Japanese encephalitis virus (JEV) vector. We also reported that the Anopheline mosquito species composition and Plasmodium vivax infection rates in malaria hot spot in Korea.

Aedes albopicuts, known as asian tiger mosquito or forest mosquito, is characterized by its black and white strips on legs and body. Ae. albopictus is an important vector mosquito for the transmission of many viral pathogens such as dengue fever and chikungunya fever. Unlike other mosquito, Ae. albopictus attacks people mainly during the daytime in the forest. To evaluate the diel activity of Ae. albopictus, three times mosquito collecting were conducted using BG Sentinel trap with dry ice in bamboo forest in Damyang-gun, Jeoullanam-do, in South Korea from August to September, 2009. Captured mosquitoes were counted and released every one hour during 25 hours experiment time. The result showed that Ae. albopictus activity began with sun rising at approximately 09:00, with peak in the early evening between 16:00 to 19:00, and ended with sunset at 21:00. Among the several factors affecting on the mosquito activity, light intensity seems to be a main factor. Especially, if the light intensity is over some threshold, it negatively effects on the activity of Ae. albopictus.

Habitats for migratory birds provide good blood source for blood sucking insects including mosquitoes, which may lead to high population mosquito species. This study was intended to know mosquito fauna in habitats for migratory birds that have preference for bird’s blood. We selected 7 locations for migratory birds (Ansan: a great reedy marsh in lake of Shihwa; Cheonan, Gyeongju, and Pyeongtaek: pine forest; Seosan: a reclaimed land near bay of Cheonsu ; Ulsan: great bamboo forest around Teahwa river) and subdivided each location with four habitats (forest, swamp, cow shed and downtown area) as mosquito collecting site. We used two types of trap for mosquito collection such as CDC black light trap and BG Sentinel trap. Additionally, we use black light and dry ice as an attractive source, respectively. A total of 27,615 mosquitoes representing 9 genera and 18 species were collected. In Ansan, 9 genera and 17 species were collected and in the other locations only 11 to 12 species. Representing by habitats shows this; in forest 9 genera and 17 species, in swamp 8 genera and 16 species, in cow shed 6 genera and 12 species, in downtown 8 genera and 17 species. The dominant species was Culex pipiens (60%) followed by Aedes vexans (11%), Anopheles spp. (8%), Aedes albopictus (7%), and Armigeres subalbatus (5%).

Japanese encephalitis virus (JEV), a mosquito-borne pathogen, is the most important cause of viral encephalitis worldwide. The major vector mosquito of this virus, known as Culex tritaeniorynchus, is mainly live in paddy rice field in Korea. So Japanese encephalitis (JE) is a disease of rural areas. During urbanization, rice cultivated land has decreased also resulting the number of JE patients has decreased. However, recent outbreak of JE in Korea 2010, the patients distribution was not related with that of the mosquito. Therefore, this study was conducted to evaluate involving other mosquito species in the transmission of JEV. Five localities, JE reported in 5 years, have been selected to collect mosquitoes according their habitats (mountain, swap, cow shed, and downtown area) in 2012. Total 22,774 collected mosquitoes were pooled by species, date and site of collection. Of the 1,282 pools, eight (five were from Culex orientalis, one from Culex pipiens complex, and two from Aedes vexans) were found positive for flavivirus RNA in SYBR Green I-based real-time RT-PCR assay. The results of sequences blasting on NCBI showed that the flaviviruses from Cx. orientalis and Cx. pipiens complex were identified as JEV genotype V.