• 한국수산과학회지
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• 제43권2호
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• pp.139-145
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• 2010

This study investigated the optimum salinity and temperature conditions for mass culture of the brackish water flea, Diaphanosoma celebensis. Community and individual cultures of flea were maintained in 1 L beakers and 3 mL vessels (of a 12-well culture plate), respectively, and fed green algae, Tetraselmis suecica. In salinity experiments ranging from 5 to 34 psu, continuous growth of flea populations was found up to 34 psu. However, the specific growth rate and life span of females showed decreasing tendencies with the increase of salinity. The highest maximum density and offspring number were 33.6 individuals (ind.)/mL and 55.3 ind. at 10 psu, respectively. In the temperature experiments ranging from 20 to $40^{\circ}C$, population growth of D. celebensis increased continuously until $35^{\circ}C$ and then decreased over $40^{\circ}C$. The specific growth rate was significantly higher at 25 and $30^{\circ}C$ than at 20 and $40^{\circ}C$. Female life span tended to decrease with temperature increase. The highest maximum density and offspring number were 52.3 ind./mL and 46.0 ind. at $30^{\circ}C$, respectively. These results suggest that the optimum salinity and temperature for mass culture of D. celebensis may be 10 psu and $30^{\circ}C$, respectively.

• Parasites, Hosts and Diseases
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• 제57권5호
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• pp.553-559
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• 2019

The Alataw Pass, near the Ebinur Lake Wetland (northwest of China) and Taldykorgan (east of Kazakhstan), is a natural habitat for wild rodents. To date, little has been done on the surveillance of Bartonella spp. and Wolbachia spp. from fleas in the region. Here we molecularly detected Bartonella spp. and Wolbachia spp. in wild rodent fleas during January and October of 2016 along the Alataw Pass-Kazakhstan border. A total of 1,706 fleas belonging to 10 species were collected from 6 rodent species. Among the 10 flea species, 4 were found to be positive for Wolbachia, and 5 flea species were positive for Bartonella. Molecular analysis indicated that i) B. rochalimae was firstly identified in Xenopsylla gerbilli minax and X. conforms conforms, ii) B. grahamii was firstly identified in X. gerbilli minax, and iii) B. elizabethae was firstly detected in Coptopsylla lamellifer ardua, Paradoxopsyllus repandus, and Nosopsyllus laeviceps laeviceps. Additionally, 3 Wolbachia endosymbionts were firstly found in X. gerbilli minax, X. conforms conforms, P. repandus, and N. laeviceps laeviceps. BLASTn analysis indicated 3 Bartonella species showed genotypic variation. Phylogenetic analysis revealed 3 Wolbachia endosymbionts were clustered into the non-Siphonaptera Wolbachia group. These findings extend our knowledge of the geographical distribution and carriers of B. rochalimae, B. grahamii, B. elizabethae, and Wolbachia spp. In the future, there is a need for China-Kazakhstan cooperation to strengthen the surveillance of flea-borne pathogens in wildlife.

• 한국환경교육학회지:환경교육
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• 제24권3호
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• pp.78-88
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• 2011

The purpose of this study is to conduct classroom-friendly learning activity for sustainable development and to find out the learner's understanding level of experiences on sustainable development. The results of this study could be summarized as follows. First, classroom-friendly learning activity for sustainable development which is focused on the sustainable flea market is concerned about enhancing learner's understanding sustainable development. It could be emphasized a viewpoint of sustainable development, and a possibility of expanding learner's experience in dealing with sustainable development. Second, this study shows also a application of the teaching & learning strategy for classroom-friendly learning for sustainable development. Three different group of pre-service teachers were participated in sustainable flea marker activity. It is considered to make the student be able to catch up core knowledge and value of sustainable development during the classroom-friendly learning activity. In conclusion, this research asserts that classroom-friendly learning activity for sustainable development could make students improve the knowledge and value of sustainable development. It is emphasized to advance education for sustainable development as a new teaching & learning strategy.

• 환경생물
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• 제39권2호
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• pp.160-168
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• 2021

Doublesex and mab-3 related transcription factor(dmrt) play crucial roles in sex determination and sex differentiation in vertebrates and invertebrates. Although dmrt genes have been identified in vertebrates, little is known about aquatic invertebrates. In this study, two dmrt genes, namely, Dc_dmrt93B and Dc_dmrt99B, were identified from brackish water flea, Diaphanosoma celebensis. Transcriptional changes were observed in the dmrt genes when the flea was exposed to bisphenol(BP), an endocrine disruptor. Sequence and phylogenetic analyses showed that both dmrt genes contained two conserved domains, namely, DM and DMA, closely clustered with those of Daphnia spp. Additionally, a significant increase in the Dc_dmrt99B mRNA expression level was observed upon exposure to intermediate concentrations of BP (bisphenol A>bisphenol S=bisphenol F, p<0.05), while the expression of Dc_dmrt93B mRNA was slightly modulated. These findings imply that the two dmrt genes may be involved in sex differentiation of D. celebensis. Furthermore, it was found that the ability of BP to modulate dmrt genes could affect development and reproduction. This study provides a basis for understanding the function of the dmrt genes and the molecular mode of action of BP in small crustaceans.

• 건설안전기술
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• 통권45호
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• pp.48-53
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• 2008

대통령자문 건설기술 건축문화선진화위원회가 이례적으로 건축물이 아닌 작품을 선정했다. 젊은 아티스트들의 작품을 전시. 판매하고 다양한 공연도 펼치는 홍대 앞의 명물 '프리마켓(www.freemarket.or.kr)'이 바로 그것이다. 일상 예술창작센터가 운영하는 프리마켓은 생활창작 아티스트 100여명이 만든 예술성을 지난 독창적인 생활용품과 장신구 미술작품 등을 전시 판매하는 곳으로 홍대 앞 어린이 놀이터 '홍익어린이공원'내에 매주 토요일 오후에 운영도는 거리 마켓이다. 유럽등지에 성행하는 Flea market(중고물품이나 생활용품을 교환 매매하는곳)과는 완전히 다른 개념인 free market 즉, 창작품과 창작행위가 펼쳐지는 예술시장인 것이다. 따라서 이곳을 찾은 외국인들은 그들 나라에서 보아왔던 Flea market로 착각하는 일도 흔히 발행하기도 하지만 어쨌든, 도심 속 외진 곳에 버려질 뻔했던 공간이 새롭게 태어나고 있는 점에서 매우 관심을 갖게 하는 곳이다.

• 한국물환경학회지
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• 제26권4호
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• pp.566-573
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• 2010

Nanotechnology has been applied to various fields in our life. Although there is a limitation of nanoparticle monitoring so far, it is expected that nanoparticles are widely distributed in environmental multimedia. Nanoparticle is known to be more toxic than its corresponding bulk material. For this reason, developed countries and international organizations are preparing for future regulation. To evaluate the safety of nanoparticles, nanotoxicity studies are internationally underway. In this study, we evaluated the research trends of ecotoxicity of nanoparticles in water environment. Test species include fish, water flea, and algae. Nanoecotoxicological studies are rapidly increasing and the experimental designs become more sophisticated. Physicochemical properties of nanoparticles should be measured and the ionization potential is important for metal-based nanoparticles. We analyzed the research trends based on the type of nanoparticles and test species. Also experimental aspects of nanoecotoxicology are considered.

• 대한수의학회지
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• 제29권4호
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• pp.433-436
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• 1989

임상적으로 건강한 진도개 203두의 혈액치(血液値)를 조사(調査)하였다. 203두에는 암수가 다 포함되어 있었으며 개의 연령은 3개월에서 10세까지 이었다. 적혈구수(赤血球數), 혈색소량(血色素量), 적혈구용적(赤血球容積) 그리고 호산구수(好酸球數) 등은 개의 연령과 함께 증가하였다. 진도개에서 나타난 높은 호산구수(好酸球數)는 심장사상충증(心臟絲狀蟲症)과 벼룩의 감염에 의한 피부염(皮膚炎)때문인 것으로 생각된다.

• Parasites, Hosts and Diseases
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• 제57권2호
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• pp.167-173
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• 2019

Rickettsial infections (Rickettsioses) are the causes of acute fever found in Thailand. It is classified as acute febrile illnesses transmitted by bloodsucking arthropod vectors (tick, flea, and chigger). This research investigated pathogens of scrub typhus in vectors from Bangkaew District, Phatthalung Province. A total of 303 pools of vector samples were ticks (Rhipicephalus sanguineus, R. microplus, and Haemaphysalis sp.), fleas (Ctenocephalides felis orientis, C. f. felis, and C. canis), and chiggers (Leptotrombidium deliense, Aschoschoengastia indica, Blankaartia acuscutellaris and Walchia disparunguis pingue) collected from reservoir hosts (dogs and rodents). The 17 and 56 kDa gene of Rickettsia causing scrub typhus were found in 29% of ticks and 98% of flea. DNA sequence analysis reveeled the detected strains were R. asembonensis and Rickettsia sp. cf1 and 5.The chiggers, 1%, were infected with Rickettsia strain TA763, a pathogen of scrub typhus.

• 한국수산과학회지
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• 제46권4호
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• pp.393-398
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• 2013

The purpose of this study was to determine how an ornamental fish, such as the fighting fish, Betta splendens would respond to the use of freshwater live-prey, such as rotifers Brachionus calyciflorus and water fleas Moina macrocopa. Ingested quantity, digestive velocity and somatic growth were compared between larvae fed a freshwater rotifer and those fed boiled yolk. Food efficiency and somatic growth were compared between larvae that were fed freshwater water fleas and those fed a micro-diet developed for flounder ($250{\mu}m$, I-hwa Ltd.). The number of rotifers ingested by larvae reached a maximum of 191 per day. However, based on the number ingested per hour and the digestive velocity of consumed rotifers, the maximum ingestible and digestible number of rotifers was calculated to be 272 per day. A maximum of 67 individuals (mean, 49.8 individuals) could be completely digested within the 1-h period from 90 to 180 min after feeding. Somatic growth was enhanced in larvae that were fed rotifers compared to those fed boiled yolk. Larvae exhibited greater growth at rotifer densities of 30 and 40 per mL than at lower densities. Among the water-flea (M. macrocopa and Bosmina sp.) and micro-particle diets, feeding with M. macrocopa resulted in the greatest somatic growth of larvae during the water-flea feeding stage.

• Journal of Veterinary Science
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• 제24권3호
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• pp.38.1-38.12
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• 2023

Background: Poor disease management and irregular vector control could predispose sheltered animals to disease such as feline Bartonella infection, a vector-borne zoonotic disease primarily caused by Bartonella henselae. Objectives: This study investigated the status of Bartonella infection in cats from eight (n = 8) shelters by molecular and serological approaches, profiling the CD4:CD8 ratio and the risk factors associated with Bartonella infection in shelter cats. Methods: Bartonella deoxyribonucleic acid (DNA) was detected through polymerase chain reaction (PCR) targeting 16S-23S rRNA internal transcribed spacer gene, followed by DNA sequencing. Bartonella IgM and IgG antibody titre, CD4 and CD8 profiles were detected using indirect immunofluorescence assay and flow cytometric analysis, respectively. Results: B. henselae was detected through PCR and sequencing in 1.0% (1/101) oral swab and 2.0% (1/50) cat fleas, while another 3/50 cat fleas carried B. clarridgeiae. Only 18/101 cats were seronegative against B. henselae, whereas 30.7% (31/101) cats were positive for both IgM and IgG, 8% (18/101) cats had IgM, and 33.7% (34/101) cats had IgG antibody only. None of the eight shelters sampled had Bartonella antibody-free cats. Although abnormal CD4:CD8 ratio was observed in 48/83 seropositive cats, flea infestation was the only significant risk factor observed in this study. Conclusions: The present study provides the first comparison on the Bartonella spp. antigen, antibody status and CD4:CD8 ratio among shelter cats. The high B. henselae seropositivity among shelter cats presumably due to significant flea infestation triggers an alarm of whether the infection could go undetectable and its potential transmission to humans.