Incubation Time Required for Hatching, and Ecological Characteristics of the Mode of Life Related with Total Numbers of the Suckers on Each Short Arm of the Hatched Juvenile Larvae of Octopus ocellatus (Cephallopoda: Octopodidae), in Western Korea

김성한,전제천 한국패류학회 2016 The Korean Journal of Malacology Vol.32 No.2

The incubation time required for hatching of O. ocellatus were investigated through the processes of egg and embryonic developments by the dissecting microscopic and visual observations. And differences in ecological characteristics of the plankton mode of life or the benthic mode of life according to total numbers of the suckers on each short arm of the hatched juvenile larvae of O. ocellatus were studied by comparisons with other octopodidae species. Compared with the recent a few results reported by other researchers associated with the incubation time required for hatching by female adult mother of O. minor (73-90 days after spawning at 20.9-21.5℃ ranges), in this study, the incubation time required for hatching by female adult mother of O. ocellatus was 56-57 days after spawning at 11.0-20.4℃. Therefore, the incubation time required for hatching by female adult mother varied with Octopodidae species. In this studies, each ovarian egg laid by a female was connected to an egg string attaching to the surface of the wall or bottom of vacunt shell of Rapana venosa. Egg and embryonic developments of this species were studied in the indoor aquaria, in the specific gravity ranging 1.024-1.025. the hatched juvenile of O. ocellatus is 10.3 mm in the mean total length and 4.5 mm in mantle length, and each of its short arms has 18-20 suckers. The just hatched juvenile larvae of O. ocellatus enter the benthic mode of life (benthic larval stage) after hatching. In particular, regarding differences in ecological characteristics of the mode of life according to total numbers of the suckers, O. vulgaris may not need to have many suckers because they enter the planktonic mode of life after hatching, however O. ocellatus may need to have many suckers, because they should adapt to the benthic mode of life. And also the just hatched juvenile larvae of O. minor (bearing many suckers more than O. ocellatus) enter the benthic mode of life (benthic larval stage) after hatching. Therefore, the total number of the suckers on each short arm of the hatched juvenile larvae can be used for determining whether an octopus species has planktonic larval stages or benthic larval stage (benthic mode of life). In particular, The intracohort cannibalism phenomena appeared at the hatched juvenile larval stage because the larval stage of O. ocellatus and O. minor enter into the benthic larval stage in the early stage, unlike entering into the plaktonic larval stage in other Octopus species such as O. vulgaris: at this time, the early hatched larvae fed the late hatched larvae (they are the same species and almost same ages). Therefore, the intracohort cannibalism pheneomena occur in the just hatched juvenile stage of only O. ocellatus and O. minor.

Incubation Time Required for Hatching, and Ecological Characteristics of the Mode of Life Related with Total Numbers of the Suckers on Each Short Arm of the Hatched Juvenile Larvae of Octopus ocellatus (Cephallopoda: Octopodidae), in Western Korea

Kim, Sung Han,Jun, Je-Cheon The Malacological Society of Korea 2016 The Korean Journal of Malacology Vol.32 No.2

The incubation time required for hatching of O. ocellatus were investigated through the processes of egg and embryonic developments by the dissecting microscopic and visual observations. And differences in ecological characteristics of the plankton mode of life or the benthic mode of life according to total numbers of the suckers on each short arm of the hatched juvenile larvae of O. ocellatus were studied by comparisons with other octopodidae species. Compared with the recent a few results reported by other researchers associated with the incubation time required for hatching by female adult mother of O. minor (73-90 days after spawning at $20.9-21.5^{\circ}C$ ranges), in this study, the incubation time required for hatching by female adult mother of O. ocellatus was 56-57 days after spawning at $11.0-20.4^{\circ}C$. Therefore, the incubation time required for hatching by female adult mother varied with Octopodidae species. In this studies, each ovarian egg laid by a female was connected to an egg string attaching to the surface of the wall or bottom of vacunt shell of Rapana venosa. Egg and embryonic developments of this species were studied in the indoor aquaria, in the specific gravity ranging 1.024-1.025. the hatched juvenile of O. ocellatus is 10.3 mm in the mean total length and 4.5 mm in mantle length, and each of its short arms has 18-20 suckers. The just hatched juvenile larvae of O. ocellatus enter the benthic mode of life (benthic larval stage) after hatching. In particular, regarding differences in ecological characteristics of the mode of life according to total numbers of the suckers, O. vulgaris may not need to have many suckers because they enter the planktonic mode of life after hatching, however O. ocellatus may need to have many suckers, because they should adapt to the benthic mode of life. And also the just hatched juvenile larvae of O. minor (bearing many suckers more than O. ocellatus) enter the benthic mode of life (benthic larval stage) after hatching. Therefore, the total number of the suckers on each short arm of the hatched juvenile larvae can be used for determining whether an octopus species has planktonic larval stages or benthic larval stage (benthic mode of life). In particular, The intracohort cannibalism phenomena appeared at the hatched juvenile larval stage because the larval stage of O. ocellatus and O. minor enter into the benthic larval stage in the early stage, unlike entering into the plaktonic larval stage in other Octopus species such as O. vulgaris: at this time, the early hatched larvae fed the late hatched larvae (they are the same species and almost same ages). Therefore, the intracohort cannibalism pheneomena occur in the just hatched juvenile stage of only O. ocellatus and O. minor.

실시간 동적 위성항법을 위한 단일차분 위치영역 Hatch 필터의 설계

이형근(Hyung Keun Lee),C. Rizos,지규인(Gyu-In Jee) 한국항공우주학회 2005 韓國航空宇宙學會誌 Vol.33 No.7

본 논문에서는 위상평활화코드 기법에 기반한 실시간 동적 차분위성항법의 효율적인 구현을 위하여 위치영역 Hatch 필터를 새로이 제안하고 그 성능을 분석하였다. 제안된 위치영역 Hatch 필터는 기존의 거리영역 Hatch를 새로운 각도에서 해석하고 이를 연장하여 유도되었다. 시뮬레이션을 통하여 Hatch 이득이 Kalman 형 이득보다 더 효율적이며 또한 위성의 출몰이 빈번한 환경에서는 위치영역 Hatch 필터가 거리영역 Hatch 필터보다 유리함을 보였다. A position domain Hatch filter is proposed as an efficient carrier-smoothed-code processing algorithm for real-time kinematic differential global satellite navigation systems. The well-known range domain Hatch filter is newly interpreted with a stochastical point of view. The interpretation result is extended to derive the position domain Hatch filter. By a covariance simulation, it is shown that Hatch gain is, in general, more efficient than Kalman-type gain in carrier-smoothed-code processing and the proposed position domain Hatch filter is more advantageous than the conventional range domain Hatch filter if the visible satellite constellation changes during the positioning task.

생쥐배아의 부화와 탈각에 미치는 Pronase의 영향

문신용,최성미,김희선,류범용,오선경,서창석,김석현,최영민,김정구,최규홍,이진용,Moon, Shin-Yong,Choi, Sung-Mi,Kim, Hee-Sun,Ryu, Buom-Yong,Oh, Sun-Kyung,Suh, Chang-Suk,Kim, Seok-Hyun,Choi, Young-Min,Kim, Jung-Gu,Choi, Kyu-Hong,Lee, Jin-Y 대한생식의학회 2000 Clinical and Experimental Reproductive Medicine Vol.27 No.4

Objective: Hatching of the blastocyst from the zona pellucida (ZP) is a key event in mammalian implantation. In vivo, two factors have been identified as possible mediators of hatching: lysis of the ZP by substances elaborated either from the embryo or female reproductive tract and pressure exerted on the zona by expansion of the blastocyst. Two methods of zona manipulation were already in use to enhance the ability of embryos to hatch: mechanical PZD and chemical ZD by acidic Tyrode's solution. But several controversies of each method have been reported. The purpose of this study was to investigate the effect of pronase for mouse embryo hatching. Methods: Mouse embryos were obtained following ovulation induction of $F_1$ animals. Fresh and cryo-thawed morula embryos were exposed to 0.5, 1.0, 2.0, 5.0 ${\mu}g/ml$ pronase in Ham's F10 for 72 hrs. Main outcome measures were the rates of partial hatching and completely hatched blastocysts, and cell number of it. Results: In fresh and cryo-thawed group, the rates of completely hatched blastocyst were significantly higher in 5 ${\mu}g/ml$ pronase treatment group than control group. There was no difference in completely hatched blastocyst total cell number between pronase treatment group and control group. This suggest that pronase treatment did not harmful in mouse embryo development. In pronase treatment group, zona pellucida were thinner than control group. Conclusion: The addition of pronase to culture media may accelerate the hatching of embryo. So, enzymatic treatment of the zona may provide a valuable and effective assisted hatching technique for human in-vitro fertilization-embryo transfer.

부화시 체중 및 정강이 길이가 꿩의 육성기 체중에 미치는 영향

양영훈,이현종,김규일,김준,김대철 濟州大學校 農科大學 動物科學硏究所 1995 動物科學論叢 Vol.10 No.1

A total of 514 birds were used to investigate the influence of body weight and shank length at hatch on the body weights at various ages in growing pheasant. Statistical model included the terms of hatch and sex as fixed effects and the two covariates of body weight and shank length a t hatch. In this model. the effects of hatch and sex on the body weights at the age of 4, 8, 12, 16 and 20 wk, and the average daily gains from hatch to 8 wk and from 8 to 16 wk of age were highly significant(P<0.01). All the regression coefficients of body weights and average daily gains on the body weight at hatch were also significant(P< 0.01). Their estimates were 3.05, 7.21, 13.89. 15.18 and 15.33 for the body weights at 4, 8, 12, 16 and 20 wk of age : 0.111 and 0.142 for the average daily gains from hatch to 8 wk. and from 8 to 16 wk of age, respectively. On the shank length, only the regression coefficients of the body weights at 4 and 8 wk of age and the average daily gains from hatch to 8 wk of age were significant(P<0.01). Results of this study suggest that body weight at hatch do significantly affect the body to, the 20 wk of age. but the shank length at hatch influences the body weights only at early age.

부화시 체중 및 정강이 길이가 꿩의 육성기 체중에 미치는 영향

양영훈,이현종,김규일,김준,김대철,Yang, Y.H.,Lee, H.J.,Kim, K.I.,Kim, J.,Kim, D.C. 한국가금학회 1995 韓國家禽學會誌 Vol.22 No.1

A total of 514 birds were used to investigate the influence of body weight and shank length at hatch on the body weights at various ages in growing pheasant. Statistical model included the terms of hatch and sex as fixed effects and the two covariates of body weight and shank length at hatch. In this model, the effects of hatch and sex on the body weights at the age of 4, 8, 12, 16 and 20 wk, and the average daily gains from hatch to 8 wk and from 8 to 16 wk of age were highly significant(P<0.01). All the regression coefficients of body weights and average daily gains on the body weight at hatch were also significant(P<0.01). Their estimates were 3.05.7.21. 13.89, 15.18 and 15.33 for the body weights at 4. 8, 12, 16 and 20 wk of age ; 0.111 and 0.142 for the average daily gains from hatch to 8 wk, and from 8 to 16 wk of age, respectively. On the shank length, only the regression coefficients of the body weights at 4 and 8 wk of age and the average daily gains from hatch to 8 wk of age were significant(P<0.01). Results of this study suggest that body weight at hatch do significantly affect the body weights in the growing periods up to' the 20 wk of age, but the shank length at hatch influences the body weights only at early age.1)

스플라인 백래시에 의한 유도탄 해치시스템의 토크 외란 분석

변영철(Young Chul Byun),강이석(E Sok Kang) 대한기계학회 2014 大韓機械學會論文集A Vol.38 No.1

본 논문에서는 유도탄 해치시스템의 스플라인 백래시에 의한 토크 외란에 대하여 실험을 통한 분석을 다룬다. 유도탄 해치시스템은 무거운 해치를 수직으로 상승시키기 위하여 스플라인과 기어열을 사용하고 있다. 해치의 회전축에 적용된 스플라인은 일반적으로 큰 동력전달을 위한 자동차의 구동 부품으로 사용된다. 스플라인은 각도 백래시를 갖고 있으며, 저크를 발생시킨다. 또한 해치 스플라인의 백래시는 해치의 흔들림 발생에 영향을 준다. 스플라인 백래시와 해치의 흔들림은 해치 회전각 및 해치의 가속도를 측정함으로써 실험적으로 분석된다. 해치의 흔들림은 짧은 시간동안 육안으로 관찰되며, 회전각의 변화 및 해치 가속도에 의해 측정된다. 해치의 각 변화에 대한 변동형태 및 지속시간은 토크와 유사하며, 백래시에 의한 해치의 흔들림은 토크 외란을 발생시킴을 보여준다. This paper presents the experimental torque disturbance analysis of a missile hatch system by spline backlash. The missile hatch system uses a spline and gear train for vertical elevation of the heavy hatch. The spline used for the rotation shaft of the hatch is generally used for automotive driving parts that transmit high amounts of power. It has an angular backlash, which results in jerks. Backlash of the hatch spline influences hatch swinging. The spline backlash and hatch swing are experimentally analyzed by measuring the hatch"s rotation angle and acceleration. Hatch swing is visually observable for a short period, and it is measured by measuring the rotation angle variation and hatch acceleration. The shape of fluctuation and duration time of hatch angle variation are similar to those of torque. This shows that the hatch swing due to spline backlash generates torque disturbances.

쥐노래미 Hexagrammos otakii 난의 부화에 미치는 수온의 영향 및 자치어의 성장과 생존에 미치는 수온과 먹이의 영향

강희웅,정의영,이창훈,이정열 한국어류학회 2002 韓國魚類學會誌 Vol.14 No.2

쥐노래미 Hexagrammos otakii의 부호조건 및 자치어의 성장 및 생존에 미치는 영향을 조사하기 위하여 수온에 따른 부화 소요시간 및 부화율, 자치어의 성장과 생존에 미치는 수온과 먹이조건을 조사하였다. 쥐노래미 수정란의 수온별 부화 소요시간은 수온이 높을수록 짧았다. 부화율은 12℃에서 가장 높았으나, 반면 수온이 14℃ 이상으로 상승하면 급격히 감소되었으며 18.0℃이상에서는 비정상 기형 개체들이 출현하였다. 부화 후 70일 경과 후 수온별 자치어의 초기 성장과 생존율(%)은 수온이 높은 조건(16℃)일수록 낮은 수온조건보다 성장이 빨랐던(P<0.01) 반면, 생존율은 낮은 수온(10℃)조건에서 높게 나타났다. 70일간 먹이공급계열이 따른 자치어 사육실험에서 최적 성장과 높은 생존 조건은 윤충류(Brachionus plicatilis, 부화 후 1~10일) + Artemia nauplii(부화 후 10~20일) + 배합사료(부화 후 15~70일)를 공급한 실험군으로 나타났다. 자치어의 빠른 성장과 생존율을 높이기 위해서는 되도록 일찍 배합사료에 먹이붙임을 하는 것이 바람직하다고 판단된다. To obtain optimal rearing conditions for seedling production of the greenling Hexagrammos otakii, the effects of seawater temperature on hatching of egg, and seawater temperature and feeding regime on growth and survival of hatched larvae were studied. The hatching time of fertilized eggs of H. otakii decreased with increasing seawater temperature. Total length of hatched larvae was in the range of 7.21~8.16㎜. The highest hatching rate was found at 12℃. As seawater temperature increased higher than 14℃, the hatching rate sharply decreased. Abnormal larvae were found at 18.0℃. Seawater temperature affected significantly the growth and survival of H. otakii larvae(P<0.001). After rearing larvae for 70 days after hatching, we found the growth rate highest when seawater temperature was highest(16℃), whereas survival was highest when seawater temperature was lowest(10℃). Feeding regime also affected significantly the growth and survival of H. otakii larvae(P<0.001). The most efficient feeding regime was under the conditions of feeding rotifer(Brachionus plicatilis) during days 1~10 after hatching+ Artemia nauplii during days 10~20 after hatching+commercial feeds during days 15~70 after hatching. To ensure rapid growth and higher survival of H. otakii larvae, commercial feeds should be provided as early as possible.

Implications of High Temperature and Low Humidity on the Hatching in the Silkworm, Bombyx mori L. Under LD 12 : 12 Condition

Reddy P. Lakshminarayana,Naik S. Sankar,Reddy N. Sivarami Korean Society of Sericultural Science 2005 International Journal of Industrial Entomology Vol.11 No.2

The implications of temperature (25, 30 and $35^{\circ}C$) and relative humidity (RH; 60, 70 and $80\%$) on the hatching rhythmicity and hatching parameters (percentage and duration) were studied in the silkworm, Bombyx mori L. under natural photoperiod (LD 12 : 12). Disease free layings (DFLs) of two pure silkworm breeds, Pure Mysore (PM, a multivoltine breed) and $NB_4D_2$ (a bivoltine breed), and their hybrid, $PM{\times}NB_4D_2$ were introduced into the experimental conditions on the $3^{rd}$ day of oviposition till completion of hatching. The hatching rhythm was predominantly diurnal under all temperature and humidity conditions, with peaks just after 'lights-on' phase (6 hrs). Extreme temperature and humidity conditions did not alter the hatching rhythmicity, but prolonged the hatching durations, extending it to the next day, coupled with reduced hatching percentage in PM and $PM{\times}NB_4D_2{\cdot}In\;NB_4D_2$, on the other hand, hatching did not extend to the next day. Hatching percentage in this breed, however, reduced below the economic level under high temperature and low humidity conditions. The high temperature and low humidity together, though did not alter the rhythmicity, seems to exert synergetic effect on the hatching percentage and its duration in the silkworm, B. mori.

Activation of peroxisome proliferator-activated receptor δ (PPARδ) accelerates blastocyst hatching in mice

Jung Ah Yoon,Hee Jung Kang,Soo Jin Hwang,Hyunjung Lim,Haengseok Song 한국발생생물학회 2011 한국발생생물학회 학술발표대회 Vol.30 No.-

In particular, maternal prostacyclin (PGI2) is critical for embryo implantation and the action of PGI2 is not mediated via its G protein-coupled membrane receptor, IP, but its nuclear receptor, peroxisome proliferator-activated receptor δ (PPARδ). Recently, several studies have shown that PGI2 enhances blastocyst development and/or hatching rate in vitro, and subsequently implantation and live birth rates in mice. However, the mechanism by which PGI2 improves preimplantation embryo development in vitro remains unclear. Using molecular, pharmacologic and genetic approaches, we show that PGI2-induced PPARδ activation accelerates blastocyst hatching in mice. mRNAs for PPARδ, RXRs (heterodimeric partners of PPARδ) and PGI2 synthase are temporally induced after zygotic gene activation and their expression reaches maximum levels at the blastocyst stage, suggesting that functional complex of PPARδ can be formed in the blastocyst. Carbaprostacyclin (cPGI, a stable analogue of PGI2) and GW501516 (a PPARδ selective agonist) significantly accelerated blastocyst hatching but did not increase total cell number of cultured blastocysts. Whereas U51605 (a PGIS inhibitor) interfered with blastocyst hatching, GW501516 restored U51605-induced retarded hatching. In contrast to improvement of blastocyst hatching by PPARδ agonists, PPAR antagonists significantly inhibited blastocyst hatching. Furthermore, deletion of PPARδ at early stages of preimplantation mouse embryos caused delay of blastocyst hatching, but did not impair blastocyst development. Taken together, PGI2-induced PPARδ activation accelerates blastocyst hatching in mice.