• 한국가금학회지
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• 제51권2호
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• pp.73-82
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• 2024

육계의 장내 미생물 균총은 전반적인 건강을 유지하고 사육 생산성에 영향을 미치는 중요한 요소이다. 하지만 한국의 여름철 고온 환경과 밀집 사육 시스템은 육계에게 스트레스를 유발하여 장내 미생물 균총의 불균형을 유발할 수 있다. 이러한 배경으로 본 연구는 한국의 복지형 농가와 일반 농가에서 봄과 여름철 육계의 장내 미생물 균총을 비교분석하기 위해 수행되었다. 19일령 육계 총 31수를 공시하였으며, 봄철 일반농가(n = 8); 여름철 일반농가(n = 8); 봄철 복지농가(n = 7); 여름철 복지농가(n = 8)에 각각 할당되었다. 계절 간 일반 농가와 복지 농가 육계의 맹장내 미생물 조성 차이를 분석하기 위해 Beta diversity 분석을 수행하였으며, 일반 농가와 복지 농가 모두 맹장내 미생물 구성이 뚜렷한 차이를 보였다. 일반 농가에서 맹장내 미생물 균총 분포를 문 수준에서 분석한 결과, Bacteroidetes의 비율은 봄철이 여름철과 비교해 높은 풍부도를 보였다. 속 수준에서 분석한 결과, 봄철 육계는 Bacteroides와 Alistipes의 비율이 여름철과 비교해 높은 풍부도를 보였다. 복지 농가에서 맹장내 미생물 균총 분포를 문 수준에서 분석한 결과, 봄철과 여름철 모두에서 Firmicutes와 Bacteroidota가 우점하였다. 하지만, LEfSe 분석 결과, 미생물 균총 구성의 차이는 일반 농가와 비교해 상대적으로 적었다. 결론적으로 우리의 결과는 고온 스트레스가 육계의 맹장내 미생물 균총에 악영향을 줄 수 있지만, 주거 환경의 개선이 고온 스트레스의 영향을 완화시켜줄 수 있음을 시사한다.

• 물과 미래
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• 제11권2호
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• pp.62-69
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• 1978

Interstational and interseasonal analyses of the correlation and variability in the seasonal and annual precipitation for 10 basic synoptic stations in South Korea, on the basis of rainfall record of over 40 years, are carried out. It is found that the climatic regions of precipitation could be classified by means of the interstational analysis for the correlations. Corrleation coefficients in interstational relationship of precipitation are lowest in autumn which characterizeds a strong locality while the highest value shows a relatively weak locality in winter. Interseasonal relationship between summer and winter precipitation shows mostly 10 percent significant level with all positive values. The magnitude of the variation coefficients are appeared to be in the order of winter, autumn, spring and summer. It is shown that the highest which is winter ranges between 0.33 0.58, and for the lowest summer, 0.26-0.44, respectively in the areal distribution of the coefficient. The secular changes of the variation coefficient in the recent trend show increases in spring at two station; Seoul and Incheon, in summer at Busan and in autumn at two stations; Busan and Incheon while in winter show devreases at the whole stations. An annual variation seems to show generally a constant trend as whole for all the stations.

• 한국환경보건학회지
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• 제39권6호
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• pp.513-521
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• 2013

Objectives: This study was performed in order to detect indicator bacteria in drinking spring water (DSW) samples in Seoul Metropolitan City, and to identify their genus through 16S rRNA sequencing and then assessing the genetic relation of their strains. Methods: For indicator bacteria detection and identification of total coliforms, we analyzed DSW between the spring and summer seasons. In particular, DSW samples were chosen from sites repeatedly found unsatisfactory in recent years. Results: Heterotrophic plate counts of DSW in the spring and summer season were investigated in the range of 0-550 and 0-800 CFU/mL, respectively. Total coliforms of these were 0-1,900 and 0-2,100 CFU/100mL, fecal coliforms were 0-600 and 0-550 CFU/100mL, and Escherichia coli were 0-7 and 0-326 MPN/100mL. The detection ratio of fecal pollution indicators and that of fecal coliforms increased to 58.6% in the summer from 12.5% in the spring and Escherichia coli increased to 51.4% from 4.7%. As a result of genetic analysis on the isolated bacteria, the genus of total coliforms was classified in the order of Enterobacter spp. 12.7%, Serratia spp. 7.3%, E. hermanii 6.4%, Rahnella spp. 5.5%, Hafnia spp. 4.5%, Escherichia coli 3.6%, Klebsiella spp. 3.6% in the spring season. In the summer season, it was classified in order of Klebsiella spp. 16.6%, Enterobacter spp. 13.0%, Escherichia coli 11.0%, Serratia spp. 8.6%, Raoultella spp. 7.0%, Kluyvera spp. 5.6% and Citrobacter spp. 3.0%. Conclusions: The increase of fecal pollution in summer indicates that special attention to drinking DSW is required.

• 한국환경과학회지
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• 제7권3호
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• pp.275-280
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• 1998

In order to clarify the seasonal composition and abundance of zooplankton commuuty In Macheon Bay. the study was carried out trimonthly during the period from April 1996 to January 1997. 1 species of Cnidana. 1 species of Annelida, 2 Ima of Moiluscs.3 species of Rotifera, 4 species and 4 larspecies was Tintinnopsis beroidea In the spring, Copepodite In the summer, Tintinnopsis beroidea In the autumn and Ceratium risus In the winter. Abundance of zooplankton ranged firom 4.720 to 41,215 Inds./1 It was high In the summer (41,215 inds./l) and low In the spring 14,720 inds./l). Dominant index ranged from 0.133 (in the spring) to 0.551 (in the winter). Species diversity inden ranged from 1.114 (in the winters to 1.996 (in the spring).

• Ocean and Polar Research
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• 제30권1호
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• pp.1-10
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• 2008

In order to find the effect of intertidal sediments on nutrient cycle in coastal environment, we measured ammonia, nitrate, phosphate, and silicate concentrations every hour during at least 12 hours in the entrance of Keunso Bay during four seasons. The content of ammonia and silicate do not change considerably with season, but nitrate shows large seasonal variation. In summer, nitrate concentration was much lower than in other seasons, which resulted from large biological uptake and active denitrification in intertidal sediments during summer. Phosphate also exhibit seasonal variations, but not that large like nitrate. N/P and N/Si ratios were lower in summer than in other seasons, which was due to active denitrification in the intertidal sediments during summer. For all seasons, ammonia concentrations were higher at low tide than at high tide, but nitrate concentrations were higher at high tide. Dissolved inorganic nitrogen concentrations measured in spring, summer, and winter were higher at high tide than at low tide, but in fall, they were higher at low tide than at high tide. For spring and winter, phosphate and silicate concentrations were higher at low tide than at high tide, while in summer and fall, they were higher at high tide than at low tide. In Keunso Bay, intertidal sediments affect significantly the nutrient cycle around the coastal areas. The intertidal sediments act as a source for ammonia and silicate, but as a sink for nitrate. However, phosphate is not considerably influenced by intertidal sediments.

• Journal of Microbiology and Biotechnology
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• 제31권6호
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• pp.803-814
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• 2021

A pilot-scale biocover was constructed at a sanitary landfill and the mitigation of methane and odor compounds was compared between the summer and non-summer seasons. The average inlet methane concentrations were 22.0%, 16.3%, and 31.3%, and the outlet concentrations were 0.1%, 0.1%, and 0.2% during winter, spring, and summer, respectively. The odor removal efficiency was 98.0% during summer, compared to 96.6% and 99.6% during winter and spring, respectively. No deterioration in methane and odor removal performance was observed even when the internal temperature of the biocover increased to more than 40℃ at midday during summer. During summer, the packing material simultaneously degraded methane and dimethyl sulfide (DMS) under both moderately thermophilic (40-50℃) and mesophilic conditions (30℃). Hyphomicrobium and Brevibacillus, which can degrade methane and DMS at 40℃ and 50℃, were isolated. The diversity of the bacterial community in the biocover during summer did not decrease significantly compared to other seasons. The thermophilic environment of the biocover during summer promoted the growth of thermotolerant and thermophilic bacterial populations. In particular, the major methane-oxidizing species were Methylocaldum spp. during summer and Methylobacter spp. during the non-summer seasons. The performance of the biocover remained stable under moderately thermophilic conditions due to the replacement of the main species and the maintenance of bacterial diversity. The information obtained in this study could be used to design biological processes for methane and odor removal during summer and/or in subtropical countries.

• Asian-Australasian Journal of Animal Sciences
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• 제27권6호
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• pp.818-824
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• 2014

The nutrient composition of pasture, voluntary intake and digestibility of diet ingested by goats grazing on an introduced Leymus chinensis pasture were measured across spring (May), summer (July), autumn (October) and winter (March). In each season, 12 Inner Mongolian Cashmere goats (6 wethers and 6 does with an average live weight of $22.2{\pm}1.3$ kg and $19.5{\pm}0.8$ kg, respectively) were used to graze on a 2 hectares size paddock. Diet selection was observed and the plant parts selected by grazing goats and whole plant L. chinensis were sampled simultaneously. The alkane pair $C_{32}:C_{33}$ and $C_{36}$ were used to estimate intake and digestibility, respectively. The results showed that the plant parts selected by goats had higher crude protein (CP) and lower acid detergent fiber (ADF) and neutral detergent fiber (NDF) than the whole plant, especially in the autumn and winter. The voluntary intake of dry matter (DM), CP, ADF, NDF, and metabolizable energy (ME) by goats was highest in summer (p<0.05). The goats ingested more CP, ME, and less ADF in spring than in autumn (p<0.05). The intakes of DM, CP, and ME were lowest in winter (p<0.05). There were significant differences in nutrient intake between wethers and does in each season, except for the ADF and ME intake per metabolic weight ($LW^{0.75}$). The nutrient digestibilities were higher in spring and summer, and decreased significantly during the autumn and winter (p<0.05). Goats, especially wethers, had a relative constant NDF digestibility across seasons, however, the apparent digestibility of CP in both wethers and does, decreased to negative values in winter. The grazing goats experienced relatively sufficient nutrients supply in spring and summer, and a severe deficiency of CP and ME in winter.

• 한국환경복원기술학회지
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• 제22권3호
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• pp.1-14
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• 2019

With a view to developing a database of death years of Korean firs (Abies koreana) at Yeongsil in Mt. Halla and investigating their abrupt inter-annual growth reduction tree-ring analysis was employed. To this end, 10 living trees (YSL) were selected to establish a master chronology and 20 dead trees were used to date their dead years. To investigate the difference in death years by death types, 10 trees, which remained standing (YSSD) out of the 20 dead trees were selected. The rest 10 dead trees were already fallen (YSFD). Two increment cores per tree at breast height were extracted in contour direction using an increment borer. A 106-year master chronology (1911-2016) was successfully established from the 10 YSLs. Through cross-dating between individual YSSD time series and the master chronology, it was verified that 1 YSSD was dead in summer 1978, 1 YSSD between autumn 1999 and spring 2000, 2 YSSDs in summer 2007, 1 YSSD in summer 2010, 1 YSSD in summer 2012, and 1 YSSD in summer 2013. The youngest tree rings of 2 YSSDs having no bark were in 1977 and 2002. For the YSFDs, it was verified that 1 YSFD was dead between autumn 1997 and spring 1998, 1 YSFD between autumn 2001 and spring 2002, 2 YSFDs between autumn 2009 and spring 2010, 1 YSFD in summer 2010, and 2 YSFDs between autumn 2012 and spring 2013, while the youngest tree rings of 2 YSFDs having no bark were in 1989 and 2004. To note, the death years of two trees, one from each death type (YSSD and YSFD), could not be verified due to poor cross-dating with the master chronology. The inter-annual growth reductions of YSSD and YSFD occurred more frequently and intensively than YSL. Typically, the YSFD showed the most frequent and intensive inter-annual growth reduction. On comparing the inter-annual growth reductions with the corresponding records of typhoons however we could not find any reliable relationship. Finally, from prior reports and results of the current study it can be concluded that the death and abrupt growth reduction of korean fir at Yeongsil in Mt. Halla are not caused by only a certain environmental factor but various factors.

• Journal of Ginseng Research
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• 제28권4호
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• pp.165-172
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• 2004

Ginseng is traditionally cultivated worldwide in cold continental climates. It is now also being cultivated in maritime environments such as New Zealandis. This paper reports a number of growth and quality parameters for plants grown under those conditions over two growing seasons and the intervening winter dormant period. While shoot biomass peaked mid-summer, in contrast, root biomass peaked late autumn/early winter. Starch, sucrose, fructose, glucose and inositol were detected in the roots. Starch concentrations were highest in early autumn (mean 470 mg $g^{-1}$ dry weight) and lowest in mid spring (218 mg $g^{-1}$ dry weight). Sucrose concentrations were low during early summer until late autumn but increased rapidly with the onset of winter and peaked during mid spring (168 mg $g^{-1}$ dry weight). Fructose and glucose concentrations were similar and peaked in late spring (5.3 and 6.2 mg $g^{-1}$ dry weight). Inositol concentrations peaked in mid summer (1.7 mg $g^{-1}$ dry weight). Starch/sugar ratios were high during summer and autumn and low during winter and spring. Ginsenoside concentrations and profiles showed that the six major ginsenosides, Rgl, Re, Rb1, Rc, Rb2 and Rd, were present, but Rf was absent. Concentrations did not vary with sampling date. The most abundant ginsenosides were Re (15.9 to 17.5 mg $g^{-1}$ dry weight) and Rb1 (10.7 to 18.1 mg $g^{-1}$ dry weight). Combined, they accounted for < $75{\%}$ of total ginsenoside concentrations. Limited taste tests indicated that highest root quality occurred during late autumn, after the shoots had senesced. However, quality could not be related to plant chemistry.

• 한국토양비료학회지
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• 제49권6호
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• pp.699-704
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• 2016

An estimation of optimal requirement of additional N by cropping pattern and growth stage is very important for greenhouse watermelon. The objectives of this study were to estimate an amount of optimal additional N based on growth, N uptake and yield of watermelon. In order to achieve these goals, we performed the study at farmer's greenhouse with a fertigation system and watermelon was cultivated three times (spring, summer and autumn) in 2015. The levels of additional N were set up with x0.5, x0.75, x1.0 and x1.5 of the $NO_3$-N-based soil-testing N supply for watermelon cultivation. The trends of growth and N uptake of watermelon markedly differed from cropping pattern; spring (sigmoid), summer and autumn (linear). The yield of watermelon was the highest at summer season and followed by autumn and spring. Also, the x1.5N showed a significantly higher yield compared to other N treatments. On the basis of growth, N uptake and yield of watermelon, we estimated an optimal level of additional N by cropping pattern and growth stage as follows; 1) spring (transplanting ~ 6 WAT : 6 ~ 14 WAT : 14 ~ harvest = 5 : 90 : 5%), summer (transplanting ~ 4 WAT : 4 ~ 8 WAT : 8 ~ harvest = 25 : 50 : 25%) and autumn (transplanting ~ 4 WAT : 4 ~ harvesting : 50 : 50%). In conclusion, nutrient management, especially N, based on cropping pattern and growth stage was effective for favorable growth and yield of watermelon.