• Korean Journal of Veterinary Research
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• v.39 no.6
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• pp.1049-1056
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• 1999

Anatomical and histological changes were studied in the dorsal, ventral, third and splenic lobes of the pancreas of the chicken embryos (8 days of incubation, 10 days of incubation to hatching). From 13 days of incubation, all four pancreatic lobes, namely, dorsal, ventral, third and splenic lobes were observed. Histologically, the pancreas of 10-14 days of incubation were consisted of mesenchymal tissue, exocrine acini and pancreatic islets. But mesenchymal tissues were disappeared from 15 days of incubation. The pancreatic ducts were observed from 14 days of incubation. The dark and light typed pancreatic islets were observed in splenic lobe from 13 days of incubation, in the third lobe from 11 days of incubation, and in the dorsal lobe from 13 days of incubation. But no dark typed islets were observed in the ventral lobes.

• Mycobiology
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• v.34 no.2
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• pp.83-91
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• 2006

Characteristic growth patterns of Cordyceps militaris isolates on various media, under varying light conditions and at varying incubation periods were examined. Light was found to be the most critical single factor in determining the density, texture, and pigmentation of the mycelial culture of the fungus. However, under the light condition, the degree of pigmentation and mycelial density were found to be affected by the incubation period and type of medium. Irrespective of the variations in medium type or incubation period, there was no pigmentation of the mycelium under dark condition. Radial growth of the mycelium was faster under dark incubation rather than under light incubation. Abundant mycelial density and darkest pigmentation of C. militaris isolates were produced in nutritionally rich media like SDAY, SMAY and CZYA, suggesting that these media may fulfill all the requirements for vegetative growth of the fungus. Growth characteristics of C. militaris isolates could be easily observed by the simple agar culture method, which would be useful to characterize the phenotypic characteristics of large number of pure cultures of the fungus under given conditions of growth factors such as medium, light and temperature.

• Journal of Sericultural and Entomological Science
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• v.10
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• pp.59-62
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• 1969

It is very important physiological and economical problems to hatching within a day by increasing hatching-ratio of silkworm eggs in sericulture, and modified dark incubating method was experimented in Japan. The author studied on the economical problems of that rather than physiological study. Hatching was induced and accelerated by illumination before hatching 5 days which incubated in the dark room after eye spot pigmented eggs emerged 10-20 percentage. It was increased by 80-90％ in hatching-ratio, but the hatching was delayed a day. In autumn silkworm, newly hatched silkworms were hatched silkworms were hatched in the dark room because of high temperature period tough modified dark incubation was passed only 4 days. The author wonder which is more effective between effect of increasing the hatching-ratio and the health of silkworms.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.12
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• pp.1702-1707
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• 2002

The effects of dark-control (D) and continuous green light (GL) exposure of incubated meat-type breeder eggs (Hybro) on embryonic growth from 5 to 15 days of age, hatching time, hatchability per cent and chick hatching weight were investigated in three consecutive experiments at 33, 38, and 41 weeks of age. A total of 798 eggs were used in this study. Eggs were set in an incubator on trays either in the D or under two tubes of 20-watt green fluorescent light during the first 18 days of incubation. Eggs from both treatments were transferred to the dark hatching compartment at 19 days of incubation. The light intensity was in the range of 1,340 to 1,730 lux at the surface of the eggs. GL incubation of eggs significantly (p<0.01) increased weight (expressed as an absolute value) and daily weight gain of embryos at 11 and continued to 15 days of age, hatchability per cent by 4.8%, reduced dead embryos per cent and chick weight at hatch by 37 and 2%, respectively and accelerated hatching time by about 24 h when compared with the D-control incubation. Chicks hatched at 504 h of incubation had significantly (p<0.01) higher body weight, expressed as an absolute value or as a percentage of egg weight, than those hatched earlier at 456 h of incubation. It was concluded that the GL incubation of meat breeder eggs reduced incubation period and chick weight at hatch and increased embryonic growth and hatchability per cent.

• Korean Journal of Ecology and Environment
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• v.38 no.spc
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• pp.22-26
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• 2005

Egg incubation periods of 14 species of plecoptera were examined at $10^{\circ}\;{\sim}\;11^{\circ}C$, $15^{\circ}\;{\sim}\;16^{\circ}C$, $20^{\circ}C$, and $23^{\circ}C$ under dark conditions. The total effective temperature (TET) was calculated by multiplying mean egg incubation days and water temperature of incubation periods. The relation between the TET and the incubation temperature was used to compare the life cycle of respective species. Perlodid species had higher TET values with a positive relation to incubation temperature than those of other species. Perlid species had low TET values in the 14 species with negative to variable relation, and Chloroperlid species showed variable to positive relations to incubation temperature. These results suggest that the relation between the TET and the water temperature reflected on their habitat of respective species.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.11
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• pp.1562-1568
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• 2016

Monochromatic green light-emitting diodes (LED) light stimuli influences the posthatch growth performance of chicks. This study was undertaken with the following objectives: i) to examine whether the green LED light stimuli induces an overheating effect by determining weight loss rate of fertile eggs during incubation period; ii) to look for the development of eyes and other primary organs at different ages of embryos and newly hatched chicks. Arbor Acres fertile broiler eggs (n = 480) were randomly assigned to 3 incubation groups and exposed to continuous white light, green light, or a dark environment (control) from the first day to 19 d of incubation. The light sourced from LED lamps with the intensity of 30 lx at eggshell level. The results showed that either green or white light stimuli during incubation did not significantly affect the weight loss rate of fertile eggs, hatching time, hatchability, chick embryo, or body weight (BW), the weight percentage of heart, liver, and eyes, as well as obvious systematic abnormalities in eye weight, side-to-side, back-to-front, or corneal diameter from 15 d of embryogenesis to 6 d of posthatch (p>0.05). Compared with the dark condition, green light stimuli during incubation tended to increase feed intake (p = 0.080), improved the BW gain of chicks during 0 to 6 day posthatch (p<0.05), and increased the percentage of pectoral muscle to the BW on 3- and 6-day-old chicks. In addition, embryos or chicks in green light had lower weight percentage of yolk retention on 19 d of embryogenesis and 1 d of posthatch in comparison to those in dark or white group (p<0.05). These results suggest that providing 30 lx green LED light stimuli during incubation has no detrimental effect on the development of eyes, heart and liver of embryos and hatchlings, but does have potential benefits in terms of enhancement of the chick growth during the early posthatch stages. In addition, the fertile broiler eggs stimulated with 30 lx green LED light during incubation does not cause an overheating effect.

• Korean Journal of Veterinary Research
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• v.41 no.2
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• pp.133-138
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• 2001

The distributions and relative frequencies of the serotonin-immunoreactive cells were studied in dorsal, ventral, third and splenic lobes of developing chicken pancreas during embryonic periods (10 days of incubation to hatching) by immunohistochemical methods. The regions of pancreas were subdivided into three regions, exocrine, light and dark islets. Round and/or oval shaped serotonin-immunoreactive cells were detected in all four lobes. According to developmental stages, the types of lobes and the regions of pancreas, these immunoreactive cells were showed various distributions and relative frequencies. In exocrine portions, serotonin-immunoreactive cells were found in the splenic lobes at 13-14 days of incubation, in the third lobes from 10 days to 19 days of incubation, in the ventral lobes from 10 days of incubation to hatching and in the dorsal lobes from 11 days of incubation to hatching. In pancreatic islets, these cells were detected only in the dark islets of splenic lobes at 15 and 16 day of incubation with rare frequency. In conclusion, serotonin-immunoreactive cells decreased with developmental stages in all four lobes and their relative frequencies decreased with developmental stages.

• Journal of Plant Biotechnology
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• v.50
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• pp.267-274
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• 2023

All studies on date palm somatic embryogenesis have focused on germination in the presence of light while neglecting germination in darkness, which mimics the germination process of zygotic embryos within seeds. To improve the date palm micropropagation protocol, we investigated the effects of light and darkness incubation on the germination of indirect date palm somatic embryos and their subsequent conversion into plantlets. Darkness incubation emerged as a pivotal factor in the germination of indirect date palm somatic embryos and their successful conversion into plantlets. Darkness incubation significantly decreased the time required for the conversion of indirect somatic embryos into plantlets, halving the duration from 24 weeks to only 12 weeks. The micropropagation protocol was modified, consolidating the previous two distinct stages of germination and elongation under light incubation into a single stage under darkness incubation. These findings modified the protocol and significantly reduced the overall duration of the date palm micropropagation protocol.

• Journal of Plant Biology
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• v.35 no.2
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• pp.117-123
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• 1992

The effect of benzyladenine (BA) on lipid peroxidation and compositions of total insoluble proteins and chloroplast thylakoid protein from wheat primary leaves during senescence in the dark was studied. BA ($10^{-5}\;M$) treatment prevented conspicuously the loss of chlorophyll content and soluble and insoluble leaf protein contents in senescing wheat leaf segments during 4-day dark incubation. Under the BA treatment, especially, the level of insoluble protein was highly maintained than that of soluble protein. Also, the increase of malondialdehyde (MDA: the peroxidation product of membrane lipids) content was inhibited in the BA treated leaves. Three major polypeptide bands in quantity corresponding to 57, 26 and 12 KD molecular weight were clearly resolved with other minor bands by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) in the insoluble protein fraction. The insoluble protein profiles of the control leaves showed a remarkable decrease in the intensity of the 57 and 12 KD band except for 26 KD band in the 72 h dark incubation. This loss during dark incubation was reduced by BA treatment. More than 20 polypeptides were resolved in the chloroplast thylakoid membrane fraction with the most prominent bands which are 59 and 57 KD ($\alpha\;and\;\beta$ subunit of coupling factor: CF) and 26 KD (apoprotein of LHCP). The changes in thylakoid protein profile during 72 h dark incubation showed the rapid degradation in control, but this degradation was prevented in quantity by BA treatment. The above results suggested that BA would inhibit the peroxidation of membrane lipids, thereby preventing the loss of membrane proteins which led to the maintenance of the membrane integrity including chloroplast thylakoid.

• Journal of Plant Biology
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• v.31 no.3
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• pp.227-237
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• 1988

Effects of putrescine on senescence in detached leaves of Chinese cabbage (Brassica campestris L.) in the light were investigated. The putrescine as a potent antisenescence substane markedly inhibited chlorophyll and protein loss at the 10mM concentraton in the detached leaves during the dark incubation. In the light, however, putrescine showed the opposite effects to dark incubation. The chlorphyll loss by putrescine in the light was stopped with darktransfer, and inhibited competitively by a divalent cation Ca2+. In the light, putrescine reduced the protease activity. Putrescine, in the light, increased H2O2 content and reduced the activities of enzymes -superoxide dismutase (EC 1.15.1.1), peroxidase (EC 1.11.1.7), catalase (EC 1.11.1.6-involved in inhibiting the accumulation of free radicals. These results suggest that the effects of puterscine on chlorophyll and protein loss in detached leaves of Chinese cabbage in the light are related to the cationic nature of putrescine and the accumulation of free radicals.