Young-Eun Na

Ovipositional Characteristics of the Ussur Brown Katydid, Paratlanticus ussuriensis (Orthoptera: Tettigoniidae)

Paratlanticus ussuriensis oviposited from early July to mid-September under laboratory condition. A female laid on average 145 eggs during the period of reproduction and over 54% of the eggs were laid within 2 weeks after the first laying. The average depth of egg-laying in soil was 19.4 mm under surface. The average major axis of an egg was 5.7 mm and the minor axis was 2.0 mm. Just before hatching, the egg swelled about twice the weight of a newly laid. In tests of ovipositional preference in different types of media, more eggs were laid in soil than in vermiculite or in Oasis ® floral form. Females also prefer shaded places in the field for reproduction, away from sunshine. In terms of the strategy for egg survival, adult moves to the hill-side adjacent to orchard farm to find a proper place for their egg laying and its survival in winter.

Effects of Chilling and Overwintering Temperature Conditions on the Termination of Egg Diapause of the Ussur Brown Katydid Paratlanticus ussuriensis

Temperature effects on diapause termination of Paratlanticus ussuriensis eggs were studied by measuring embryonic development and hatching rates at various conditions of indoor chilling and overwintering temperatures. Diapausing eggs of P. ussuriensis did not hatch at continued incubation at and even after chilling for once at either or for 30, 45 and 60 days. In addition, double chillings at with a 90 days interval at did not induce hatching of diapausing eggs. However, double chillings at induced hatching at 3.626.7%. When eggs were incubated at after chilling for once at for various periods, those weights were not changed but those chilled at gradually increased to approximately 1.5 times. When 60-days-old eggs were artificially deposited under the soil at three different mountain sites in September 2007, the hatching rates of the first-overwintered eggs were 11.3, 3.5 and 4.1% and those of the second-overwintered eggs were 25.1, 21.6 and 0.4% at Hoepori, Bitanri and Hwasanri, respectively. Most eggs were hatched from mid-March to mid-April but little bit earlier in southern regions. During the hatching period soil temperatures in three tested locations were around 8 to . In overall, diapausing eggs of P. ussuriensis were greatly influenced by chilling temperature conditions and those repeated cycles, and may required overwintering for one or two times to hatch for the post-embryonic development.

The Fauna of Aquatic Invertebrates in Paddy Field

지속가능한 농업과 안전한 쌀을 생산하기 위해서는 건전 하고 균형있는 농업생태계 보전의 필요성이 대두되고 있다. 특히 환경보전에 대한 국민의 관심과 건전한 농업환경에서 , 생산된 안전농산물의 선호도가 증대됨으로서 농산물 생산지 환경의 중요성이 날로 높아지고 있다 논에 서식하는 생물들은 . 환경변화에 민감하게 반응하여 농업생태계의 건전성을 평가 하는 기준이 되고 있다. 최근 생물다양성은 국가 간의 자원경쟁과 맞물려 국가의 주권으로 인식되고 있으며 이에 따라 세계 각 국은 생물다양 , 성 유지를 위한 많은 전략들을 구상하고 있다 다양한 서식생 . 물들로 이루어진 농업생태계에서 논에 서식하는 수서무척추 동물은 논 생태계를 유지하는데 매우 중요한 지위를 차지하고 있다 하지만 천년 동안 논 생태계가 유지 관리되어 왔음에도 . , 5 ・ 불구하고 논 생태계에 서식하는 수서무척추동물에 대한 연구 는 미미한 실정이었다. 본 연구에서는 년간 논에서 채집된 표본을 토대 10 (‘97-’06) 로 수서무척추동물 약 종류를 정리하여 원색도감으로 발 222 간하였고 한민수 문 강 과 종이 논 생태계에 ( , 2006), 5 7 72 222 분포함을 보고하고자 한다.

The Flora and Vegetation Distribution in Dokdo

This study aims to investigate the flora and the vegetation of Dokdo (Dongdo). The vegetation types were investigated by the Z-M school method. A total of 44 vascular plant taxa belonging to 24 families, 41 genera, 36 species, and 11 varieties are recognized in Dongdo, Dokdo. In this study, we confirmed four species, Chenopodium serotinum, Chelidonium majus var. asiaticum, Bromus japonicus, Elymus sibiricus, that had not been previously reported. The biological type of Dokdo was determined to be type. Two main vegetation groups which were established in a rocky area with little soil development and in a developed soil layer, along the development of soil layer have been distinguished and classified into five communities. The former was composed of 1 community; Aster spathulifolius-Sedum oryzifolium community. The latter was composed of 4 communities; Agropyron tsukusiense var. transiens community, Festuca rubra-Artemisia japonica ssp. littoricola community, Miscanthus sinensis community, and Artemisia princeps community.

Effects and possible mechanisms of action of acacetin on the behavior and eye morphology of Drosophila models of Alzheimer’s disease

The human β-amyloid (Aβ) cleaving enzyme (BACE-1) is a target for Alzheimer’s disease (AD) treatments. This study was conducted to determine if acacetin extracted from the whole Agastache rugosa plant had anti-BACE-1 and behavioral activities in Drosophila melanogaster AD models and to determine acacetin’s mechanism of action. Acacetin (100, 300, and 500 μM) rescued amyloid precursor protein (APP)/BACE1-expressing flies and kept them from developing both eye morphology (dark deposits, ommatidial collapse and fusion, and the absence of ommatidial bristles) and behavioral (motor abnormalities) defects. The reverse transcription polymerase chain reaction analysis revealed that acacetin reduced both the human APP and BACE-1 mRNA levels in the transgenic flies, suggesting that it plays an important role in the transcriptional regulation of human BACE-1 and APP. Western blot analysis revealed that acacetin reduced Aβ production by interfering with BACE-1 activity and APP synthesis, resulting in a decrease in the levels of the APP carboxy-terminal fragments and the APP intracellular domain. Therefore, the protective effect of acacetin on Aβ production is mediated by transcriptional regulation of BACE-1 and APP, resulting in decreased APP protein expression and BACE-1 activity. Acacetin also inhibited APP synthesis, resulting in a decrease in the number of amyloid plaques.

Response of Ussur Brown Katydid, Paratlanticus ussuriensis to Light-Emitting Diodes(LED)

This study was conducted to determine the phototactic response of Paratlanticus ussuriensis to different wavelength of light by the use of LEDs and to provide a basic information for developing an improved trap with the longer trapping efficiency to control environment-friendly this katydid. P. ussuriensis were attracted to the single LED light source, especially, blue and white. For the multiple LED light sources, the movement of P. ussuriensis was not significantly different among LED-light bands. Overall, P. ussuriensis had a tendency to move to light source although they were not attracted to a specific wavelength of light. These methods may be used as information for conducting a phototactic response of other insects.

Up-regulation of multiple serine proteinases during earthworm tail regeneration

Summary Previous studies have shown that spatiotemporal regulation of extracellular matrix (ECM) by proteinases is implicated in the initial step of regeneration. In amphibian regeneration, the up-regulation of proteinases such as metalloproteinases (MMPs) and cathepsin D, and proteinase-related proteins such as proteinase tissue inhibitors and activators has been demonstrated. Since the earthworm could provide a unique and valuable model to investigate the mechanism of regeneration, we studied the developmental change in proteinase expression during earthworm tail regeneration. Zymographic analysis revealed that proteinase activities began to increase within 1 h after amputation and reached a maximum at 7 days post-amputation. This peak in activity was approximately 22-fold greater than the unamputated controls. Thereafter, the proteinase activities tended to decrease followed by another peak at 30 days before returning to control levels. At least four types of proteinase were distinguishable at 7 and 30 days post-amputation, with molecular weights of 25, 28, 38, and 44 kDa, respectively. All proteinase activities were strongly inhibited by addition of phenylmethylsulfonyl fluoride (PMSF) and aprotinin, specific inhibitors for serine proteinase. Pepstatin A, E-64, iodoacetamide and a metal ion-free medium were not effective inhibitors, indicating that proteinases expressed during earthworm tail regeneration would be serine proteinases. In addition, we were able to detect two types of plasminogen activator (PA) with molecular weights of 40 and 47 kDa, respectively. PA activities were predominantly expressed at 1, 5, and 25 days post-amputation, which preceded two peaks of serine proteinase activities appearing at approximately 7 and 30 days after amputation, respectively. This fact supports the view that serine proteinases expressed in respond to tail amputation may be plasmin-like proteinases activated by PA.

Geographical Distribution of Diving Beetles (Dytiscidae) in Korean Paddy Ecosystem

BACKGROUND: The paddy ecosystem is periodically disturbed with a relatively consistent cycle in short term. However, in long term aspect, the paddy as habitats of organisms has been affected by the change in farming practices. Accordingly, the composition and their densities of fauna species inhabiting the wet paddy has been changed. The geological distribution of a species is very helpful to understand the past and current status of habitats and biodiversity. METHODS AND RESULTS: We monitored 290 sites of open plain paddy or terraced valley paddy located in 138 cities or counties of South Korea and analyzed examine geological distribution of a taxon of freshwater invertebrates, diving beetles (Dytiscidae) which inhabited the paddy ecosystem. This survey was conducted from 2005 through 2007. The total species of diving beetles found in the paddy were identified to be 15 genus 26 species among the family of Dytiscidae. Among them, 24 species were found in the terraced valleys-in paddy fields, and 19 species were found in the open plain paddy fields. Eleven species of them were rarely found in the paddy. The average body size of the adult diving beetles of each species was between 2.0 and 35.0 mm. Most of the diving beetle species except for 11 species with rare frequency of occurrence were found in almost all sites of the terraced valley paddy fields but three species (Agabus browni, Agabus japnicus, and Ilybius apicalis) were not found in the open plain paddy fields. The species distributed relatively widely over some sites of the open plain paddy fields were Guignotus japonicus, and Rhantus pulverosus. Specifically, Ilybius apicalis was found in a specific region, the east-southern part of Korean peninsula, whereas Coelambus chinensis was found only in valley paddy field of the region where Ilybius apicalis was not found. Overall distribution range of diving beetles in open plain paddy fields was limited to few area than in terraced valley paddy fields. CONCLUSION(s): The differences in the range of distribution of diving beetles between terraced valley paddy fields and open plain paddy fields was thought to be the result of an complex action of physico-chemical environments such as annual water status and the degree of chemical application involving differences in the extent of disturbance of the paddy ecosystem, the connectivity of the paddy to an adjacent biotope, and interrelationships among competitors.

Effects of Climate Change on C 4 Plant List and Distribution in South Korea:A Review

It is expected that identification and lists of plants in specific regions are useful not only for the ecological researches that are related to vegetation phenology and succession but also as an index of climate change. In this review, plants growing in South Korea were listed and their life forms were investigated. In addition, we discussed the influences that climatic change and the plants exerted on plant ecosystem. Photosynthetic pathway types ( and ) for the plant species in South Korea were determined by reviewing the scientific literatures published between 1971 and 2010. Of the total 4476 species in 1123 genera and 197 families, 206 species (4.6%) in 84 genera (7.5%) and 21 families (10.7%) were identified as plants (including - intermediate plants). Among the identified species, 53 species (25.7%) in 26 genera and 15 families were classified as Dicotyledoneae, while 153 species (74.3%) in 58 genera and 6 families were classified as Monocotyledoneae. The majority of the species belong to four families: Chenopodiaceae (15 species), Amaranthaceae (13 species), Gramineae (102 speceis) and Cyperaceae (45 species). With respect to life form composition of 206 species, Th---t was most dominant: 95 species (46.1%) were included in Th, 123 species (59.7%) in , 179 species (86.9%) in , and 122 species (59.2%) in t. The projected increase in temperature due to climate change may provide better conditions for the growth of plants. Such a result will have considerable impacts on the interspecific competition between and plants, the distribution of plants, plant phenology, and plant diversity.

Evaluation of global warming effects on the geographical distribution of weeds in paddy fields by characterizing germination time and morphological factors

Abstract Global warming, a consequence of climate change, alters rice-paddy ecosystems, especially through the changes of both growth rate of plants and the occurrences of pests, and affects both rice crop production and biodiversity. In this study, factors related to the germination temperatures of 80 weed species in paddy fields were analyzed to elucidate the effect of warming on morphological (leaf size), phenological (germination time), and population (distribution) responses. A self-organizing map (SOM) was used to classify the weed species on the basis of 5 factors related to germination temperature: the minimum, maximum, and optimum temperatures and the minimum and maximum optimal range. Climate data for the Korean Peninsula during 4 different decades (1990s, 2020s, 2050s, and 2080s) were obtained from a regional climate change model following the A1B emission scenario of the Intergovernmental Panel on Climate Change. Changes in the germination time and range of potential habitable areas for the weed species were estimated on the basis of the patterns of the SOM. The species associated with relatively lower germination temperatures tended to have smaller leaves, shorter stems, and earlier flowering and germination times than the species associated with higher germination temperature. The potential germination area increased progressively with rising temperature. The degree of potential increase in germination area was the greatest in the 2080s when the weeds could germinate in most of the southern Korean Peninsula. These results suggest that studying the patterns of germination temperature through SOM could provide necessary information for characterizing the germination of weeds on the basis of various characteristics (e.g., morphology, phenology, and distribution) and would be useful for maintaining agricultural productivity and agroecosystem biodiversity under global warming.