• Asian-Australasian Journal of Animal Sciences
• /
• 제17권11호
• /
• pp.1586-1590
• /
• 2004

An experiment was carried out with day-old "Sonali" (♂RIR$\times$♀Fayoumi) chicks to investigate the efficacy of locally made low cost brooders for brooding chicks in rural areas. Three types of indigenous brooders viz. charcoal, haricane and sawdust brooders were used for brooding chicks throughout the experimental period of 28 days. The efficiency of the brooders was observed in respect of their ability to maintain temperature, fluctuation in temperature during operation and cost effectiveness. Following initial trial of temperature maintenance for 48 h, the chicks were put under the brooder stoves and brooded up to 28 days. The experimental birds were fed on chick starter diet. Maintenance of temperature with sawdust brooders was found satisfactory and optimum for brooding the chicks at different stages of brooding and at the same time involved least cost for brooding in comparison with charcoal and haricane brooders which did not perform well in generating heat necessary for brooding and were not economically feasible for poor farmers. On the other hand, performance of charcoal brooders was better in respect of temperature maintenance during initial stage (when the brooder was started) but the temperature fluctuated rapidly, whereas fluctuation of temperature was gradual in sawdust brooders. Body weight gain and feed conversion were best in sawdust brooders. Survivability was highest in sawdust brooders and lowest in haricane brooders. Sawdust brooders may be appropriate for brooding chicks in rural areas, where electricity is not available.

• 생명과학회지
• /
• 제9권5호
• /
• pp.518-524
• /
• 1999

Timing of oviposition, nuclear maturation of oocytes, egg-sperm contact and brooding were observed in the giant fresh-water prawn Macrobrachium rosenbergii reared in the laboratory. When a pre-spawning molted female was transferred to the male, the female oviposited commonly at 5 to 10 hr after mating. The first polar body were extruded within 2-3 min after spawning. The egg chromosome progressed to release second polar body by 30 min and mitotic nuclear division occurred in 8 hr after spawning. Thumbtack-shaped spermatozoa were seen peneterating egg membrane with their spike directed forward. Transformation of spermatozoa and fertilization membrane could not be observed by light microscopy. The elapsed hours from oviposition to the end of brooding wee taken in 5-7 hr. Brood size for female 9 cm and 18 cm in body length was estimated to be 10,000~15,000 and 100,000 eggs, respectively and is proportional to the total length of the berried females. The ovigerous females reared at chlorinity of 2.21~4.25$\textperthousand$Cl. showed a normal egg development up to hatching.

• 재활치료과학
• /
• 제9권2호
• /
• pp.73-86
• /
• 2020

목적 : 본 연구의 목적은 여대생의 인지(자책, 숙고) 및 행동적 회피요인과 수면의 질의 관계에서 우울증상의 매개효과를 검증하는 것이다 연구방법 : 본 연구는 지역사회 1,000명의 여대생을 대상으로 우울증상(CES-D), 반추적 반응(K-RRS), 인지-행동 회피(CBAS), 수면의 질(PSQI)을 평가하였다. 최종 분석대상은 총 947명이었다. 자료분석은 SPSS 18.0과 AMOS 22.0 통계프로그램을 사용하였다. 결과 : 첫째, 자책과 수면의 질의 관계에서 우울증상의 완전매개효과가 유의미한 것으로 나타났다. 둘째, 숙고와 수면의 질의 관계에서 우울증상의 매개효과는 유의하지 않았으며, 숙고는 우울증상을 예측하지 않았다. 셋째, 행동적 회피와 수면의 질의 관계에서 우울증상의 매개효과가 유의미한 것으로 나타났다. 또한 행동적 회피는 수면의 질을 직접적으로 예측하였다. 결론 : 본 연구는 지역사회의 일반 여대생의 우울증상과 수면문제에 대한 자책의 더 병리적인 특성을 숙고와 비교하여 입증하였다. 또한 수면문제에 영향을 미치는 우울증상과 행동적 회피 요인의 주요한 역할을 밝혔다는데 의의가 있다.

• 한국발생생물학회지:발생과생식
• /
• 제1권2호
• /
• pp.173-180
• /
• 1997

This study has been conducted to investigate the molting behavior and the effects of rearing temperature and day length on molting in the behavior and the effects of rearing temperature and day length on molting in the giant freshwater prawn, Macrobrachium rosenbergii reared in the laboratory. The results obtained were summarized as follow: 1. After pre-spawning molting, the protopodites of 1st, 2nd, 3rd, and 4th except 5th pleopod bore new breeding setae which conserve eggs in the brooding chamber and the basis of 3rd, 4th, and 5th pereiopods bore new breeding dresses which transport the ovulated eggs into the brooding chamber. 2. Adult females reared in 27.5-$29.4^{\circ}C$ molted 10-12 times per year at interval of 27-35 days, of which four or six moltings were common molting for growth and another four or five moltings were pre-spawning molting for spwaning and brooding. In winter season, pre-spawning molting did not happen to most of adult females in spite of the same temperature. 3. Duration of intermolt cycle was 31-38 days and 26-30 days at 25.3- $26.5^{\circ}C$ and 28.7- $30.4^{\circ}C$ of rearing temperature, respectively.

• 한국축산시설환경학회지
• /
• 제10권3호
• /
• pp.183-188
• /
• 2004

• 한국발생생물학회지:발생과생식
• /
• 제1권2호
• /
• pp.181-187
• /
• 1997

This study has been conducted to investigate the mating behavior, time sequence of mating and time limit with which female can fulfill spawning and brooding after pre-spawning molting in the giant fresh-water prawn, macrobrachium rosenbergii reared in the laboratory. the results obtained were summarized as follows. Mating happened spontaneously as the following sequences: courting gesture, seizure of female by male, mounting, turning of female, copulation. The entire mating lated approximately seven minutes. The endopodite of 2nd pleopod of male bore the appendix masculins whcih are male's secondary sex characteristic. cinciulli was formed at the distal portion of appendix interna which are on the upper portion of appendix masculins and helped stabilizing the connection of each side of 2nd pleopod during mating. After the connection of each side of 2nd plepod was fixed on the posterior portion of the thoracic sternum in female, a gelatinous spermatophore that emitted at the basipodite of 5th pereiopod during courting gesture was deposited on the ventral groove of 2nd, 3rd, 4th and 5th pereiopod. time limit which female can fulfill copulation and brooding was from 3 hours to 15 hours after pre-spawning molting.

• 한국수산과학회지
• /
• 제37권5호
• /
• pp.405-413
• /
• 2004

The previous morphology-based taxonomic frameworks within the family Syngnathidae had emphasized the significance of the male brood pouch and reproductive biology in defining the group. However, several different hypotheses had been proposed by different investigators. This study has been carried out to determine the phylogenetic relationships among 19 species belonging to the order Syngnathiformes with three Gasterosteiformes species as outgroup taxa by using the mitochondrial cytochrome b DNA sequences. Phylogenetic analyses based on neighbor-joining distance, maximum parsimony, minimum evolution and maximum likelihood method strongly supported that the family Syngnathidae, the suborder Syngnathoidei and the order Syngnathiformes were all monophyletic group. Although much of previous morphological analyses were supported by our molecular data, there were some significant discrepancies between molecular and morphological work. Such an interesting result was that the weedy seadragon (Phyllopteryx taeniolatus) strongly grouped together with the New Zealand pot-belly seahorse (Hippocampus abdominalis). Considering the markedly different brooding structure between them, this unexpected result might be explained whether by multiple independent origins of brooding structure or by hybridization between the female Hippocampus and other syngnathid species having individual membranous egg compartment. In addition, the suborder Aulostomoidei was paraphyletic group because the shrimpfish (Aeliscus strigatus), belonging to the family Centriscidae, always grouped together with the family Syngnathidae as a sister taxon.

• Ocean and Polar Research
• /
• 제32권4호
• /
• pp.369-377
• /
• 2010

To characterize ecotoxicological responses to a natural estrogen, $17{\beta}$-estradiol, we evaluated the life-history of the parental ($F_0$) and first generation ($F_1$) of the harpacticoid copepod, Tigriopus japonicus sensu lato. We evaluated the survival of nauplii and copepodites, the number of days until the emergence of copepodites and adult males, the sex ratio, brooding success, and the first brooding day of adult females. No significant differences in the survival rate were noted in response to treatments with different concentrations of $17{\beta}$-estradiol. However, $17{\beta}$-estradiol induced developmental delay and skewed the sex ratio toward males. Copepod development was delayed significantly in the 0.1 and $1\;{\mu}g\;l^{-1}$ $17{\beta}$-estradiol treatment groups relative to the control group, with a more pronounced delay in the $F_1$ group. Body length and biomass were significantly smaller in the $17{\beta}$-estradiol treated groups than in the controls. The male emergence of T. japonicus s.l. was very high in the 10 and $30\;{\mu}g\;l^{-1}$ $17{\beta}$-estradiol treatment group. Furthermore, exposure to $17{\beta}$-estradiol resulted in morphological deformities such as shrinking and swelling of the urosome, twisted setae of the caudal rami, setal loss of swimming legs, abnormal segmentation of antennules, and dwarfism.

• 한국콘텐츠학회논문지
• /
• 제19권3호
• /
• pp.385-395
• /
• 2019

본 연구에서는 죄책감, 수치심, 수줍음, 내부 적대감을 포함하는 자의식적 부정정서와 비자살적 자해의 관계에서 정서조절기제의 매개효과를 규명하고자 하였다. 본 연구의 대상은 J지역 3개 대학교에 재학 중인 대학생 652명으로, 이들에게 비자살적 자해, 자의식적 부정정서, 정서조절에 대한 자기보고식 설문지를 실시하였다. Process macro의 model 4를 사용한 매개분석 결과, 자의식적 부정정서는 자해행동과 유의한 관련성을 보였으며, 부정적 반추의 정서조절이 그 관련성을 매개하는 것으로 나타났다. 이러한 결과는 자의식적 부정정서가 높을수록 비자살적 자해 행동이 증가하며, 부정적 반추가 부정정서를 더욱 강화시켜 자해 행동을 증폭시킴을 확인할 수 있었다.

• 한국수산과학회지
• /
• 제22권5호
• /
• pp.351-362
• /
• 1989

Ecology of Crangon affinis was studied in the Nakdong River Estuary fron June 1988 to May 1989. The growth rate of female was similar to that of male. Size differences, however, were apparent between female and male. Sex ratio varies with season. The major spawning season was from June 1988 to May 1989 except for November 1988. The number of eggs of the largest ovigerous female (35.55mm TL) was over 4,000, while that of the smallest ovigerous female (15.05mm TL) more than 120. The mean number of eggs was 1778. The size of winter eggs is larger than that of the summer eggs. The mean percentage of egg loss from brooding to hatching was $29.06\%$. The rate of egg loss decreases with increasing age. Major component of food organisms includes mysids and polycheates.