• International Journal of Industrial Entomology and Biomaterials
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• 제22권2호
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• pp.51-57
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• 2011

Reproductive activity in the economically important insect, Antheraea mylitta is very important because the female reproduces only once in her life time and the aging is very rapid and costly. It is a capital breeder and strictly a monoandrous species. To know how strategically the insect behaves and the male allocates its ejaculate resource more prudently during its successive mating with virgin females to maximize its own fitness and the fitness of the female with whom it mated, both being most important to sericulture industry. So, the present study was undertaken and the results revealed fresh and virgin females always prefer to mate with fresh virgin males (84%) and receives high dose of ejaculates leading to higher hatchability than to virgin males of one day old (13.7%) and one day old males with mating experience (2.3%). The ejaculation size (as referred to eupyrene sperm count in the ejaculation) declined significantly over successive mating (r = -0.9931, P < 0.001), so also the male body weight (r = -0.9560, P < 0.001). The quantity of ejaculate passed to female also dramatically declined during aging (r = -0.9982, P < 0.001). It was found that male weight contribute substantially to the quantum of ejaculate (r = -0.9519, P < 0.001), so also higher fecund females receive relatively more ejaculate than the lower group to reach higher reproductive fitness. The life time fecundity was found to be $334{\pm}31$.

• International Journal of Industrial Entomology and Biomaterials
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• 제10권1호
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• pp.19-24
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• 2005

Nutrition is very essential for growth, development and reproduction. The quantitative impetus of nutritional factor on adult characters and reproductive fitness was studied in Antheraea mylitta by providing fresh leaves of Terminalia tomentosa for 1 to 4 times a day to $5^{th}$ instar larvae. All the characters have improved on giving fresh diet more times over the single diet. The adult weight has strong effect on the reproductive potential i.e., female pupa and moth weight, survivability, pupation rate, emergence percentage, fecundity, fertility, egg weight and hatched out larval weight. The improvement recorded to the tune of $70\%,\;77.1\%,\;115.4\%,\;36.7\%,\;45.9\%\;and\;218.3\%$ in larval weight gain, survivability, pupation rate, female pupa weight, moth weight and fecundity respectively when fresh diets were provided 4 times a day against single diet. The adult emergence percentage has increased from $66.4\%\;to\;96.2\%$ and fertility rose from $52.2\%\;to\;93.6\%$. The weight of eggs and the larvae hatched out of it also found to be significantly higher in 4 diets a day condition. The study revealed that optimization of fresh diet frequency should be maintained to obtain higher egg production and fertility in order to get vigorous larvae to continue the generation.

• Asian-Australasian Journal of Animal Sciences
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• 제18권11호
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• pp.1662-1668
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• 2005

This review has been done to examine sex-linked dwarf gene in broiler production in hot-humid climates. Introduction of sex-linked dwarf gene especially in hot harsh tropical environments brings a great advantage for broiler production. The heavy broiler parent suffers due to the stress of these adverse climates. Sex-linked dwarf genes reduce body weight, egg weight, but are superior for adaptability under harsh tropical environments, with a lower requirement for housing and feed, better survivability and reproductive fitness giving fewer defective eggs, more hatching eggs, better fertility, hatchability, feed conversion efficiency and resistance to disease. Overall the cost of chick production from dwarf hens is lower than from their normal siblings. Market weights of broilers from sexlinked dwarf dams is almost similar to those of broilers from normal dams with normal sires. But the net benefit of broiler production from sex-linked dwarf dams is found to be greater than that of broilers from normal dams. This will be the most important to the rural communities in Bangladesh and in other countries where the similar environment and socio-economic conditions exist. Therefore, sexlinked dwarf hens might be used in broiler breeding plan as well as broiler production in the tropics.

• 생태와환경
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• 제46권3호
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• pp.395-408
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• 2013

환경상태는 생물이 적합도 (번식성공 또는 생존율)를 극대화하기 위해서 초기생활사의 변화를 초래할 수 있다. 본 연구에서는 온도변화와 온도에 따른 수상레저활동 인구변화가 어류의 초기 생활사 특성, 즉 체세포 성장(성장속도), 번식세포 (생식소) 발달 그리고 누적스트레스의 회복과정과 어떠한 관계가 있는지를 동적상태의존모델을 이용하여 분석하였다. 우선 어류의 초기 생활사 특성이 취식행동에 영향을 받는다고 가정하였고, 이러한 관계를 고려하여 어류의 일반 생활사 모델을 개발하였다. 모델은 성장속도와 번식세포(생식소)의 발달이 온도가 상승함에 (단, 성장속도를 감소시키는 임계온도보다는 낮은) 따라 빨라졌으며, 또한 체내에 누적되는 스트레스도 함께 증가하였다. 흥미롭게도 온도가 높을 때에는 수상레저활동 인구의 증가는 성장속도와 생식소의 발달을 느리게 했지만, 스트레스의 누적은 가속화시켰다. 그러나 온도가 낮을 때에는 초기 생활사에 대한 수상레저활동 인구의 영향이 상대적으로 낮았다. 또한 최적취식행동은 높은 온도에서는 수상레저활동 인구의 변화에 관계없이 항상 높았지만, 낮은 온도에서는 수상레저활동 인구가 증가할수록 급격히 감소하였다. 초기성장기간 동안의 생존율은 온도가 낮아지고 수상레저활동 인구가 적을 때에는 취식행동이나 인간 활동에 따른 어류의 사망률 증감이 생존률 변이에 영향을 주었다. 반대로 온도가 높아지고 수상레저활동 인구가 많을 때의 생존율은 취식행동이나 사망률에 관계없이 항상 낮았다. 끝으로 본 연구를 통해 기후변화와 수상레저활동 인구변화와 관련된 어류의 초기 생활사를 수생태계 보전전략이나 건강성 평가분석에 포함시키는 것은 분석의 정확성과 정밀성을 향상시킬 수 있을 것이라 사료된다.

• International Journal of Industrial Entomology and Biomaterials
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• 제10권2호
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• pp.137-141
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• 2005

Though many insecticides are commercially available, development of resistance, pest resurgence and effects on non-target organisms led to the search for alternate insect pest management (IPM) strategy based on larval growth and reproductive fitness. Reproductive potential of insects depends on its acquiring of vitellogenic competence which is under hormonal control. Exogenous application of analogues of JR (JHAs) and ecdysterone could derail normal development and reproduction in insects by manipulating an array of physiological processes. In the rice pest, brown planthopper, Nilaparvata lugens, JHA, hydroprene induced metathetely from the fifth (final) instar nymphs in an age-dependent manner. Day 0 of the final instar showed highest sensitivity to induce this abnormal development. Adults emerged from treated day 3 nymphs looked normal. Both the morphotypes were reproductively incompetent and showed partial to complete sterility. Pre-adult exposure of the ovarian tissue to hydroprene suppressed mitotic division of germinal cells and induced abnormalities in the later s1ages of growth and differentiation of ovary in N. lugens. More over the nymphal exposure to hydroprene inhibited patency changes of follicular epithelium and affected competence of the follicles for yolk sequestration. In the absence of ovarian growth and oocyte differentiation, germarium found disintegrated, trophic core regressed and terminal oocytes resorbed. Hydroprene exposure to newly ecdysed brachypterous females did not affect ovarian development and egg production. Proper larval-adult transition appeared as a. prerequisite for vitellogenic competence in N. lugens for which the ovarian tissues must be exposed to ecdysterone in the internal milieu devoid of JH.

• Animal cells and systems
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• 제2권1호
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• pp.55-63
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• 1998

The effects of inflorescence herbivory and flowering time on plant architecture and reproductive yields were examined with a perennial herbacious species, Vicia cracca, occurring in Natick, Massachusetts, USA. Natural herbivory on inflorescences was observed among the total of 157 plants during a growing season. Vegetative and reproductive characters were measured in the field as well as in the lab depending on the characters. Approximately 64% of the plants were subjected to herbivory on inflorescences. Plants were classified into three groups; unbrowsed plants, partially browsed, and totally browsed plants, according to the level of herbivory on inflorescences of each plant. Plants were also categorized by their flowering time such as early vs late flowering plants. Herbivores tended to favor inflorescences on rather small plants, resulting in a pattern of totally contact or partially intact inflorescences on taller plants. The mean number of stems, which was assumed to be a direct result of severe herbivory in this population, differed among herbivory groups. There also was a tendency that plants flowering late in the season had more nodes with more leaves, suggesting that herbivory on stem tips early in the season before flowering might have induced growth of side branches or branchlets along the main stems. Comparison between unbrowsed and partially browsed plants showed that the latter compensated for browsing in terms of numbers of inflorescences, fruits, seeds and seed size (weight), though they did not compensate in flower number. The probability of fruit production (presence vs absence of fruits) and seed weight declined toward the end of the season. These results suggest that resources are deficient at the end of the season. Almost complete reproductive failure in totally browsed plants is attributed to the destruction of inflorescence display and the disadvantage of small vegetative size of those plants. After all, in this population, a moderate level of herbivory on inflorescences did not reduce the maternal fitness of the plants. However, severe herbivory on inflorescences resulted in antagonistic interactions between plants and herbivores.

• 한국양봉학회지
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• 제33권4호
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• pp.261-268
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• 2018

Queen honey bees (Apis cerana) can be reared artificially on demand by the use of grafting technique. The technique consists of grafting young worker larvae into queen cell cups and raising in a queenless strong colony. As the age of grafted larvae for queen rearing exhibited several aspects related to quality and reproductive potential of queen, this study were conducted to investigate the influence of age of grafted larva on morphological characteristics and lifespan of queen, and the growth of colony she headed. Our results demonstrated that queens reared from young worker larvae (i.e., less than 1-day old larvae) were significantly larger in size (i.e., body weight and thorax width) than that of queens reared from 2-day old worker larvae. Moreover, queens reared from younger worker larvae initiated egg-laying earlier, stored more spermatozoa in spermatheca and had a longer lifespan compared to queens raised from older worker larvae. We also found a significant positive effect of queen grafting age on the production of worker and drone brood, adult worker population in colonies headed by queens reared from younger larvae. These findings suggested that rearing queens from brood grafted at the earliest possible age could increase the reproductive potential of queen as well as fitness of colony she head.

• Animal cells and systems
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• 제6권3호
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• pp.233-237
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• 2002

The pheromonal repelling response occurs when a combination of female and male pheromones is found to be less attractive to courting males than are female pheromones alone. This repelling response may act to conserve a courting males’reproductive fitness by minimizing ma1e-male competition within a courting group. Recently, a Pheromonal repelling response was first reported for vertebrates in the red-spotted newt, Notophthalmus viride-scens. A male cloacal pheromone, a ∼33 kDa protein, was identified as a repelling pheromone. In this study, to determine whether both the main olfactory epithelium (MOE) and/or the vomeronasal organ (VNO) are activated by the repelling pheromone, we recorded electrical field potentials from both olfactory epithelia while applying the repelling pheromone. The repelling pheromone induced electrical responses from both olfactory organs, and the magnitude of the response was greater in the VNO than in the MOE. Our results suggest that both the VNO and MOE may be involved in the pheromonal repelling response.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.650-654
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• 2000

Particle Imaging Velocimetry (PIV) is becoming one of essential methods to measure velocity fields of fluid flows. In this paper, a genetic algorithm capable of tracking same particle pairs on two separated images is introduced. The fundamental of the developed technique is based on that on-to-one correspondence is found between two tracer particles selected in two image planes by taking advantage of combinatorial optimization of the genetic algorithm. The fitness function controlling reproductive success in the genetic algorithm is expressed by physical distances between the selected tracer particles. The capability of the developed genetic algorithm is verified by a computer simulation on a farced vortex flow.

• Molecules and Cells
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• 제39권10호
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• pp.715-721
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• 2016

Plants have become physiologically adapted to a seasonally shifting environment by evolving many sensory mechanisms. Seasonal flowering is a good example of adaptation to local environmental demands and is crucial for maximizing reproductive fitness. Photoperiod and temperature are major environmental stimuli that control flowering through expression of a floral inducer, FLOWERING LOCUS T (FT) protein. Recent discoveries made using the model plant Arabidopsis thaliana have shown that the functions of photoreceptors are essential for the timing of FT gene induction, via modulation of the transcriptional activator CONSTANS (CO) at transcriptional and post-translational levels in response to seasonal variations. The activation of FT transcription by the fine-tuned CO protein enables plants to switch from vegetative growth to flowering under inductive environmental conditions. The present review briefly summarizes our current understanding of the molecular mechanisms by which the information of environmental stimuli is sensed and transduced to trigger FT induction in leaves.