• 환경위생공학
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• 제16권4호
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• pp.38-46
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• 2001

The purposes of this study were to examine applicability of waste egg shells as conditioning agent, to determine the optimum conditions for improving digested sludge dewaterability and to compare with before and after adding them. It estimated that the optimum conditions were dosage 30 g/L, particle size 10mesh, temp. $30^{\circ}C$, pH 7 and dewatering pressure $2.66{\pm}10^4{\;}N/m^2$. On the basis of induced optimum conditions, if adding waste egg shells in digested sludge, its specific resistance was $1.13{\pm}10^{12}{\;}m/kg$ and was low about 3 times than raw digested sludge $3.5{\pm}10^{12}{\;}m/kg $. Therefore, in view of waste recycling, it seemed that we could utilize waste egg shells as conditioning assent for improving dewaterability of digested sludge.

• Applied Microscopy
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• 제39권3호
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• pp.237-243
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• 2009

담수산 잉어과(Cyprinidae), 황어아과(Leuciscinae)에 속하는 버들치(Chinese minnow; Rhynchocypris oxycephalus)의 난자형성과정과 성숙난 난막의 미세구조를 광학현미경과 전자현미경으로 관찰한 결과는 다음과 같다. 난원세포의 세포질은 호염기성이었고 핵 내에 다수의 인들이 분포하고 있었다. 제1난모세포의 경우 난황포가 단지 난세포 가장자리에만 배열되어 있었고 난막의 형성은 관찰되지 않았다. 제2난모세포에서는 난막이 형성되었고 제1난모세포에 비해서 난황포가 점점 핵 쪽으로 증식된 경향을 보였다. 발생이 진행됨에 따라서 호염기성 물질들은 점점 감소하는 경향을 보였고 후에 난막 주위에만 국한적으로 분포하였으며, 난막의 두께와 난자의 크기는 점점 증가되었다. 배란된 성숙난 난막의 표면은 미세융모와 같은 구조물들에 의하여 덮혀 있었고 동물극 쪽에 깔떼기 형태의 난문이 발견되었다. 난막의 단면을 확인한 결과 부착성 외층과 섬유상 내층 모두 2층으로 구성되어 있었다. 이상과 같이 버들치의 난자형성과정은 난세포의 크기 증가, 난황낭의 축적, 염기성 물질의 감소, 난막발달 및 두께의 증가로 요약될 수 있으며 이 패턴은 잉어과의 공통적인 특징으로 생각된다. 그러나 배란된 성숙난 난막의 미세구조적 특징들은 이 종만이 가지는 종특이성으로 종을 분류하는 데 이용될 수 있다.

• Animal cells and systems
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• 제3권4호
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• pp.375-383
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• 1999

Gonadal development, gametogenesis, reproductive cycle, and first sexual maturity of Reishia clavigera were investigated monthly from July 1998 to June 1999 through cytological and histological observations. R. clavigera had separate sexes, and was an internal fertilizer. The ma1e penis was located near the two tentacles. The ovary and testis were composed of a great number of oogenic lobules and spermatogenic tubules, respectively. The size of ripe oocyte ranged from 130 to 140 ${\mu}$m in diameter. The peripheral cytoplasm of the germinal vesicle of the ripe oocyte in many cases were surrounded by smaller yolk granules, while the eccentric cytoplasm was occupied with larger ones. The reproductive cycle of R. clavigera could be classified into five successive stages: early active, late active, ripe, spawning, and recovery. Spawning of females occurred from early July to August when the seawater reached above 24.8$^{\circ}C$. Spawning of males occurred from early June to August in the water above 22.8$^{\circ}C$. Minimum size for sexual maturity of both sexes was above 10.0 mm in shell height. Each egg capsule was a cylinder or spindle in shape, 4-6 mm in length and 1-2 mm in width. Colors of newly spawned egg capsules showed yellowish white or pale yellow, while those with veliger larvae showed pale black, and released larvae or dead egg capsules showed black violet. The fecundity in an egg capsule ranged from 70 to 91 eggs (mean＝80.28 eggs).

• 한국수산과학회지
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• 제55권1호
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• pp.23-29
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• 2022

This study was carried out to clarify the egg, larvae and juveniles development of Misgurnus anguillicaudatus, and relationships of M. anguillicaudatus and M. mizolepis, Cobitididae Fishes. The adult fishes were collected in Samsan-cheon, Haenam-gun, Jeollanam-do, Korea and their spawning inducement was carried by ovaprim injections. The egg shape was circular and the size was average 1.12 mm. The eggs were hatched at 61 to 72 h after fertilization. The newly hatched larvae had an average 3.23 mm in total length (TL). At 5 days after hatching, the larvae reached to post larval stage and they were 10.3 mm in TL. At 19 days after hatching, it reached to juvenile stage and was 25.3 mm in TL. The egg size of M. anguillicaudatus was almost same as M. mizolepis but the hatching period of M. anguillicaudatus has taken longer. It was possible for interspecific distinguishability of M. anguillicaudatus and M. mizolepis when their larvae reached to juvenile stage by the development of keel-like ridges.

• The Korean Journal of Ecology
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• 제25권4호
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• pp.241-245
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• 2002

During the breeding season of 1998, breeding ecology of the Great Reed-Warbler (Acrocephalus arundinaceus orientalis) was studied at Yangsoo-ri and Yongdam-ri of the Yangpyung-gun, Kyunggi province, Korea. Egg-weight (CV: 6.25) was more variable than either length or breadth, and breadth was the least variable of the measures. Significant variations in overall egg-weight occurred between clutches, and that more of the total variation in egg-weight and shape are due to inter-clutch variation as to intra-clutch variation when the data were pooled. The last egg tends to be larger than the remaining eggs in the clutch of the Great Reed-Warbler, suggesting the Great Reed-Warbler may adopt the brood-survival strategy. When method 3 was used, the most common incubation period is 12 days. In the Great Reed-Warbler, the length of the incubation period was related to clutch-size when method 1 (r=0.485, p<0.05) and method 2 (r=0.621, p<0.01) were employed, but not related to egg weight. The averagee number of days of hatching asynchrony was 2.5, raging 0.5~2.5. Asynchronous hatching was related to the clutch size (r=0.66, p<0.01). Hatching sequence was closely related to the laying sequence (r=0.93, p<0.001), suggesting Great Reed-Warblers incubate their eggs before clutch completion. The effect of egg weight on hatching asynchrony was found in Great Reed-Warblers (t-test, p<0.01).

• 한국동물위생학회지
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• 제23권3호
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• pp.263-269
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• 2000

This study was carried out to set a standard of damage compensation by researching state of damage due to noises in laying and prelaying hens. Recently, there are many damage cases in chicken farms near construction site that were caused by noises of construction. Therefore disputes and complaints about economical loss have increased ceaselessly. But we have few research and report such a thing. The result have shown that the weight loss rate was ranged from 9.48% to 23.2% and mortality of laying period of hens was higher than prelaying period. Pathological findings were fatty liver, congestion and hemorrhage of intestine, erosion of proventriculus and gizzard in order of case frequency. And these signs in hens of laying period was more serious than prelaying period. Half-life rate of antibody titers against Newcastle disease and infectious bronchitis in sound stressed hens was no different compared with non-stressed hens. Egg production rate dropped from 38% to 45% according to strength of noises. Before being stressed, hens produced special, large, middle, small-size eggs in the order. But after being stressed, their egg Production rate of middle, small-size Increased while egg production rate of special, large-size decreased. Production rate of soft and broken shell eggs was 0.015% in the stressed flocks higher than 0.005% in the non-stressed flocks.

• 한국수산과학회지
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• 제31권2호
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• pp.288-295
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• 1998

한국 동해 남부 연안 일광만에서 요각류 Arasrtia steueri의 알 생산력을 조사하였다. 실험실에서 온도 및 엽록소 $\alpha$ 농도와 알 생산력간의 관계식을 유도한 후, 현장의 수온과 엽록소 $\alpha$ 농도를 적용하여 현장 개체군의 알생산력을 추정하였다. 알의 평균 크기는 $80.52{\mu}m$이었고, 성체 암컷의 두흉부 길이와 알의 크기간에는 유의한 상관이 없었다. 현장 개체군의 알 생산력은 $0.32\~63.32{\mu}gC\;m^{-3}d^{-1}$ (평균 $13.33{\mu}gC\;m^{-3}d^{-1}$)이었으며, 알의 수로 나타내 면 $7.1\~1407.1\;eggs\;m^{-3}d^{-1}$(평균 $296.1\;eggs\;m^{-3}d^{-1}$)이었다. 암컷 한 마리당 알 생산력은 $5.4\~12.5\;eggs\;female^{-1}d{-1}$(평균 $8\;eggs\;female^{-1}d{-1}$)이었으며, 비알 생산율은 $0.028\~0.117\;d^{-1}$(평균 $0.064\;d^{-1}$)로 나타났다. 본 연구에서 추정된 알 생산력 (성체 암컷의 탄소 무게의 백분율)은 과소 평가된 것으로 나타났는데, 성체의 알에 대한 잠재적인 포식 가능성이 이러한 낮은 알 생산력과 관련이 있는 것으로 판단된다.

• Journal of Ecology and Environment
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• 제29권6호
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• pp.545-550
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• 2006

2003$\sim$2005년의 쇠제비갈매기 Sterna albifrons의 번식기 동안 충남 홍성군 간월호의 번식군집에서 총 10개의 과산란수의 둥지(nest with supernormal clutch)와 7개의 이종 알 혼합 둥지(nests with mixed species clutch, 쇠제비갈매기와 흰물떼새의 알이 혼합된 둥지)가 관찰되었다. 쇠제비갈매기의 알 회수 행동은 한 배 산란수와 관계없이 두 번째 알 산란 이후 높은 빈도를 보였다. 알 회수 행동은 모든 포란 단계에서 매우 높은 빈도로 나타났다. 쇠제비갈매기는 둥지에서 약 15 cm 떨어진 알에 대하여 높은 알 회수 행동 비율을 보였으나 35$\sim$55 cm의 거리에서 급격히 감소하였고 60 cm 거리에서는 알 회수 행동이 나타나지 않았다. 쇠제비갈매기는 알의 종류 및 크기와 관계없이 둥지 인근에 배치된 알들을 자신의 둥지로 편입시키는 행동을 보였다. 본 조사 결과는 쇠제비갈매기의 알 회수 행동이 과산란수의 둥지 및 이종 혼합 둥지를 생성할 가능성이 있음을 시사한다.

• 한국가금학회지
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• 제21권2호
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• pp.139-150
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• 1994

Egg cholesterol has been a hot issue in respect of it's effect on health and diseases in human. There is a general recognition that the cholesterol from eggs is similar to that from the other dietary sources in its biochemical functions. Many evidences show that egg yolk increased plasma cholesterol levels at an average rate of 2.3 mg /100 rnL plasma for every 100 mg cholesterol consumed. The elevation of plasma cholesterol could, however, be altered by various dietary factors such as ratios of polyunsaturated fatty acids and saturated fatty acids. Blood cholesterol levels of Korean adults have been raised up to, on the average, 193 and 187 mg /100 mL plasma for men and women, respectively, from 167/5 mg /100 mL in 1980. Furthermore, proportion of hypercholesterolemics(> 210 mg /dL) has been increased up to 23% of the population. These changes in blood cholesterol levels are attributed to the changes of dietary patterns, suggesting the arguement that Koreans are insensitive to changes of blood cholesterol is not right. Egg cholesterol levels have never been successfully reduced to any significant levels even with tremendous amounts of efforts made during last decades. The alternative and the best way to control blood cholesterol level originating from egg consumption appeares to enrich egg fat with omega-3 series fatty acids. Ingestion of the fatty acid group has specific functions to reduce hypertension and prevent various types of cancer as well as to reduce blood cholesterol. Another way to reduce egg cholesterol directly is to produce smaller egg yolk without reducing whole egg size since cholesterol is located only in the yolk. It is important to keep faith with consumers by providing correct informations on eggs, meanwhile efforts need to focus on to improve the quality of eggs as one of the best protein food items.

• 대한본초학회지
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• 제22권4호
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• pp.45-50
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• 2007

Objectives : The purpose of this study is to determine dose of Gypsum and Natrii sulfas in Shanhanlun and Geumgyeyoryak Methods : We measured the egg size Gypsum, and Natrii sulfas 1 Seong(升), and Results : 1. The weight of GYPSUM, egg is about $48{\pm}4g$, it will end up with 104g, when applying egg gravity of 1.055 and Gypsumls weight of 2.3. 2. One Ryang(兩) is equal to 6.5g in Sanghanlun and Gumgyeyoryak, and therefore the weight of ones gypsum is equal to 1 Keun(斤). 3. Compare to a dose of Gypsum is equal to one egg in Mokbanggitang. 4. Maximum dosage of Gypsum is equal to half an egg, 8Ryang(兩) of Sanghanlun, which is 52g. 5. Daily dosage of One Keun(斤) of Natrii sulfas is 8 Ryang(兩), of sanghanlun, which is 52g, Maximum dosage of Sanghanlun is 4 Ryang(兩), which is 26g. Conclusion : As stated above we may acknowledge that a dosage of Gypsum and Narii sulfas in either Sanghanlun and Keumgyeyoryak is applicable range in practical clinic.