Enhancement of Seaweed Rhizoid and Blade Formations by the Chlorophyte Codium fragile Extract

Mehader Getachew(메더 게타츄),Paulos Getachew(폴로스 게타츄),Ji-Young Cho(조지영),Jae-Suk Choi(최재석),Yong-Ki Hong(홍용기) 한국생명과학회 2016 생명과학회지 Vol.26 No.4

많은 생물체들은 다른 생물체들의 성장, 생존, 재생에 영향을 미치는 allelochemical 물질들을 생성함으로서 자신들의 영역을 유지 확장할 수 있다. 천연 생물촉진활성을 가진 allelochemicals을 찿기 위하여 18종의 흔한 해조류를 대상으로 실험실에서 편리하게 배양가능한 둥근돌김의 중성포자들로부터 가근 및 유엽의 형성 촉진효과를 탐색하였다. 그중 가장 활성이 높은 녹조류 청각의 추출물은 약 100 및 50 μg/ml 농도에서 최대 및 반 정도의 중성포자로부터 가근 형성 촉진효과를 나타내었다. 또한 청각 추출물은 중성포자 배양 초기에 가근형성, 가근갯수, 가근길이, 유엽형성, 유엽길이 등의 성장을 촉진시켰다. 이 같은 다른 해조류의 성장을 촉진시키는 allelochemicals들은 천연 해조류 촉진제의 개발 및 유용 해조류 종들의 유지관리 등에도 활용될 가능성을 지닌다. Living organisms can maintain or extend their territories by producing allelochemicals that influence the growth, survival, and reproduction of other organisms. To identify natural biostimulants of positive allelochemicals, we screened 18 common seaweed extracts for enhancement of rhizoid and blade production in a convenient Porphyra suborbiculata monospore assay. By addition of methanolic extract from the most potent green seaweed, Codium fragile, 100% and 50% enhancement doses reflecting the amount of C. fragile extract required to enhance rhizoid formation (in terms of number of spores with rhizoids per total spores tested) were approximately 100 and 50 μg/ml, respectively, in the P. suborbiculata monospore culture. The C. fragile extract quickly enhanced rhizoid formation, rhizoid numbers per rhizoid-holding spore, rhizoid length, blade formation (in number of spores with blade per total spores tested), and blade length from most monospores at early culture days. The extract enhanced rhizoid formation after 2 days of culture significantly, rhizoid numbers per rhizoid-holding spore after 3 days, rhizoid length after 3 days, blade formation after 2 days, and blade length after 1 day, respectively, from most monospores. The allelochemicals that enhanced favorite seaweed species may be efficacious for new seaweed management technologies, including the development of biostimulant agents based on natural products.

Rebuilding a War-Damaged Country : The Case of Cambodia

Getachew Felleke 대한공간정보학회 2008 한국지형공간정보학회 학술대회 Vol.2008 No.12

Cambodia is at once faced with both enabling opportunities and encumbering realities as it proceeds with the rebuilding of its post civil-war economy. Its location in the economically vibrant region of Southeast Asia combines with its proud record of historical achievements to hint at a positive promise and a hopeful prospect of success. But its recent history of self-destructive politics and fratricidal conflict has left a traumatized society with gaping institutional deficits - these deficits have at times threatened to make the economic prospects ahead a bit more daunting and less certain than can normally be expected. Which outcome will in the end prevail is contingent primarily on the optimum husbanding of its economic and political resources domestically while, at the same time, effectively mining its trade and investment opportunities externally. This paper is focused on the domestic aspect of the developmental challenges that Cambodia currently faces.

A Novel Approach to Improve the Uncertainty of River Flow Projections

Getachew Tegegne,Kim, Youngil,Kim, Sung Jin,Kim, Young-Oh 대한토목학회 2017 대한토목학회 학술대회 Vol.2017 No.10

INVESTIGATION OF DYE-REGENERATION KINETICS AT DYE-SENSITIZED p-TYPE CuCrO 2 FILM/ELECTROLYTES INTERFACE WITH SCANNING ELECTROCHEMICAL MICROSCOPY

GETACHEW ALEMU,MINGKUI WANG,BINGYAN ZHANG,JUNPENG LI,XIAOBAO XU,JIN CUI,YAN SHEN 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.5

The power conversion e±ciency of p-type dye-sensitized solar cells (DSSC) is determined by thekinetics of hole injection and dye-regeneration reaction at the dye/electrolyte interface. In thiswork, the photochemical regeneration kinetics of dye adsorbed on CuCrO 2 mesoporous ¯lm wasinvestigated by using scanning electrochemical microscopy with feedback mode. Organic P1 andC343 sensitizers in combination with iodide-based and thiolate-based electrolytes were selected tounderstand the e®ect of sensitizers and redox shuttles on dye-regeneration process. A fast re-generation kinetic rate constant was con¯rmed in thiolate-based sample compared with iodide-based electrolyte, indicating that the organic redox shuttle was an e±cient mediator to optimizethe performance of p-type DSSC.

Performance of Some Introduced Korean Garlic (Allium sativum L.) Cultivars in Ethiopia

Getachew Tabor,Seong Sook Han,Do-Ham Pae,Soonsung Hong,Fekadu Gebretinsay,Demis Fikru 한국국제농업개발학회 2021 韓國國際農業開發學會誌 Vol.33 No.2

마늘은 에티오피아에서 양념으로 쓰이는 가장 중요한 작목 중 하나이다. 그럼에도 생산성은 세계 평균의 절반 수준에 머물고 있는 실정이다. 이렇게 생산성이 낮은 주요 원인으로는 품종의 다양성 부족, 낮은 영농기술 수준과 병해충 등을 들 수 있겠다. 이를 극복하기 위하여 한국의 농촌진흥청 국립원 예특작과학원으로부터 13종류의 마늘 품종이 도입되어 데브라 자이트와 쿨룸사에 위치한 농업연구소(Debre Zeit and Kulumsa agricultural research centers)에서 예비 실험이 진행 되었다. 도입된 13 품종 중에서 Namdo, Daeseo 및 Wangyo 57022 등 3 품종에서만 주아 (bulbil)가 형성이 되었다. 한국에서 도입된 마늘 3 품종의 적응성을 조사한 결과는 아래와 같이 정리할 수 있다. 1. Namdo 품종은 구근의 직경이 38~60 mm였고 무게는 25.1 g부터 92.7까지로 다양하였다. 구근은 8~11 쪽으로 구성 되었다. 2. Namdo와 Daeseo 등 한국 품종들은 Kuriftu라는 지역 품종에 비하여 구근의 크기는 약 2배 정도 컸으며, 마늘 쪽의 무게는 약 5배 정도 무거웠다. 하지만 성숙까지의 기간은 지역 품종(120일)에 비하여 약 60일 이상 길었다 (179일). 3. 쿨룸사 농업연구소에서 진행된 재배결과에서는 지역 품종인 Tesday의 생산량은 12.87 t/ha으로 Namdo (9.53 t/ha) 및 다른 실험군에 비하여 유의적으로 높았다. 하지만 Namdo 품종의 구근 무게는 지역 품종인 G-104/94에 비하여 50% 이상 높은 것으로 확인된 반면, 쪽의 숫자는 9개로 G-94-1/94의 14 개와 Tseday의 23개 보다 유의적으로 적었다. 즉, 상품성 측면에서 한국 품종이 우수하다는 결과로 사료되었다. 4. 파종시기에 따른 Namdo 품종의 발달 차이를 살펴본 결과 높이, 7월 중순에 파종한 경우가 8월이나 9월에 파종한 경우보다 마늘 쪽의 두께, 크기 및 무게가 유의적으로 우수한 것으로 확인되었다. 한국에서 도입된 품종 중에서 특히, Namdo의 경우 성장 기간이 조금 떠 짧아질 수 있다면 에티오피아에서 생산이 가능한 품종으로 판단된다. Garlic is one of the most important crops used as condiments in Ethiopian. However, its productivity of garlic is less than half the world average. Lack of productive varieties and improved agronomic practices, as well as diseases and insect pests are the major causes of low productivity. The objective of the present study was to investigate an adaptive performance of some introduced garlic genotypes of Korean varieties in Ethiopia. The thirteen garlic genotypes were imported from the National Institute of Horticulture and Herbal Sciences (NIHHS), Rural Development Administration, Republic of Korea. The genotypes were tested for adaptation at Debre Zeit and Kulumsa agricultural research centers. Among the thirteen genotypes tested, only three genotypes Namdo, Daeseo, and Wangyo 57022 formed bulbs, while the remaining ten genotypes did not form bulbs despite the long growth period (179 days) taken to mature. The three genotypes had bigger bulbs and fewer but bigger cloves compared to the local varieties such as G-94-1/94, G-104-1/94, and Holeta local. A follow up replicated trial comparing Namdo with three local varieties was undertaken at Kulumsa. The replicated trial also showed that Namdo had better yield than the three local varieties. Moreover, it produced bigger bulbs and cloves than all the local varieties, which eases household and industrial processing of cloves. Therefore, verification of Namdo for production in Ethiopia could provide a better option for processing garlic.

Self-Healing Hydrogel Pore-Filled Water Filtration Membranes

Getachew, Bezawit A.,Kim, Sang-Ryoung,Kim, Jae-Hong American Chemical Society 2017 Environmental science & technology Vol.51 No.2

<P>Damages to water filtration membranes during installation and operation are known to cause detrimental loss of the product water quality. Membranes that have the ability to self-heal would recover their original rejection levels autonomously, bypassing the need for costly integrity monitoring and membrane replacement practices. Herein, we fabricated hydrogel pore-filled membranes via in situ graft polymerization of 2-acrylamido-2-methyl-1-propanesulfonic acid (AMPS) onto microporous poly(ether sulfone) (PES) substrates and successfully demonstrated their self-healing ability. Covalent attachment of the hydrogel to the substrate was essential for stable membrane performance. The membranes autonomously restore their particle rejection up to 99% from rejection levels as low as 30% after being physically damaged. We attribute the observed self-healing property to swelling of the pore-filling hydrogel into the damage site, strong hydrogen bonding, and molecular interdiffusion. The results of this study show that hydrogel pore-filled membranes are a promising new class of materials for fabricating self-healing membranes.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/esthag/2017/esthag.2017.51.issue-2/acs.est.6b04574/production/images/medium/es-2016-04574y_0011.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/es6b04574'>ACS Electronic Supporting Info</A></P>

Rebuilding a War-Damaged Country : The Case of Cambodia

Getachew Felleke 한국평화연구학회 2008 평화학연구 Vol.9 No.4

Does bryozoan colonization alter the biochemical composition of Saccharina japonica affecting food safety and quality?

Getachew, Paulos,Kang, Ji-Young,Choi, Jae-Suk,Hong, Yong-Ki Walter de Gruyter GmbH 2015 Botanica marina Vol.58 No.4

<B>Abstract</B><P>The encrusting bryozoan</P>

Distribution and larval breeding habitats of Aedes mosquito species in residential areas of northwest Ethiopia

Getachew Ferede,Moges Tiruneh,Ebba Abate,Wondmeneh Jemberie Kassa,Yitayih Wondimeneh,Demekech Damtie,Belay Tessema 한국역학회 2018 Epidemiology and Health Vol.40 No.-

OBJECTIVES: The Aedes mosquito is a vector for transmitting many arboviruses. Knowledge of the breeding habitat of this vector is vital for implementing appropriate interventions. Thus, this study was conducted to determine the breeding habitats and presence of Aedes mosquito species in the study areas. METHODS: A house-to-house cross-sectional survey of Aedes mosquito breeding habitats was carried out in Metema and Humera, Ethiopia, in August 2017. All available water-holding containers present in and around houses were inspected for the presence of immature stages of Aedes mosquitoes, and they were collected and reared to the adult stage for species identification. In the larval survey, the house index, container index, and Breteau index were computed as risk indices. RESULTS: Of the 384 houses surveyed for the presence of Aedes mosquito larval breeding, 98 were found to be positive for larvae. During the survey, a total of 566 containers were inspected, of which 186 were found to be infested with Aedes mosquito larvae, with a container index of 32.9, a house index of 25.5, and a Breteau index of 48.4. The most common Aedes mosquito breeding habitats were discarded tires (57.5%), followed by mud pots (30.0%). Of the 1,077 larvae and pupae collected and reared, Aedes aegypti (49.3%), Ae. vittatus (6.5%), and Culex species (44.2%) were identified. CONCLUSIONS: Discarded tires were the most preferred breeding habitats for Aedes mosquitoes. Moreover, Ae. aegypti, the main vector of dengue and other arboviruses, was identified for the first time in this region, suggesting a high potential for arbovirus transmission in the study areas.

Visceral leishmaniasis treatment outcome and its determinants in northwest Ethiopia

Getachew Mebrahtu Welay,Kefyalew Addis Alene,Berihun Assefa Dachew 한국역학회 2017 Epidemiology and Health Vol.39 No.-

OBJECTIVES: Poor treatment outcomes of visceral leishmaniasis (VL) are responsible for the high mortality rate of this condition in resource-limited settings such as Ethiopia. This study aimed to identify the proportion of poor VL treatment outcomes in northwest Ethiopia and to evaluate the determinants associated with poor outcomes. METHODS: A hospital-based retrospective study was conducted among 595 VL patients who were admitted to Kahsay Abera Hospital in northwest Ethiopia from October 2010 to April 2013. Data were entered into Epi Info version 7.0 and exported to SPSS version 20 for analysis. Bivariate and multivariate logistic regression models were fitted to identify the determinants of VL treatment outcomes. Adjusted odds ratio (aORs) with 95% confidence intervals (CIs) were used, and p-values <0.05 were considered to indicate statistical significance. RESULTS: The proportion of poor treatment outcomes was 23.7%. Late diagnosis (≥29 days) (aOR, 4.34; 95% CI, 2.22 to 8.46), severe illness at admission (inability to walk) (aOR, 1.63; 95% CI, 1.06 to 2.40) and coinfection with VL and human im muno­deficiency virus (HIV) (aOR, 2.72; 95% CI, 1.40 to 5.20) were found to be determinants of poor VL treatment outcomes. CONCLUSIONS: Poor treatment outcomes, such as death, treatment failure, and non-adherence, were found to be common. Special attention must be paid to severely ill and VL/HIV-coinfected patients. To improve VL treatment outcomes, the early diagnosis and treatment of VL patients is recommended.