• Journal of Ecology and Environment
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• 제35권1호
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• pp.1-7
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• 2012

To calculate and predict soil carbon budget and cycle, it is important to understand the complex interrelationships involved in soil respiration rate (Rs). We attempted to reveal relationships between Rs and key environmental factors, such as soil temperature, using a laboratory incubation method. Soil samples were collected from mature deciduous (MD), mature coniferous (MC), immature deciduous (ID), and immature coniferous (IC) forests. Prior to measure, soils were pre-incubated for 3 days at $25^{\circ}C$ and 60% of maximum water holding capacity (WHC). Samples of gasses were collected with 0, 2, and 4 h interval after the beginning of the measurement at soil temperatures of 5, 15, 25, and $35^{\circ}C$ (at 60% WHC). Air samples were collected using a syringe attached to the cap of closed bottles that contained the soil samples. The $CO_2$ concentration of each gas sample was measured by gas chromatography. Rs was strongly correlated with soil temperature (r, 0.93 to 0.96; P < 0.001). For MD, MC, ID, and IC soils taken from 0-5 cm below the surface, exponential functions explained 90%, 82%, 92%, and 86% of the respective data plots. The temperature and Rs data for soil taken from 5-10 cm beneath the surface at MD, MC, ID, and IC sites also closely fit exponential functions, with 83%, 95%, 87%, and 89% of the data points, respectively, fitting an exponential curve. The soil organic content in mature forests was significantly higher than in soils from immature forests (P < 0.001 at 0-5 cm and P < 0.005 at 5-10 cm) and surface layer (P = 0.04 at 0-5 cm and P = 0.12). High soil organic matter content is clearly associated with high Rs, especially in the surface layer. We determined that the incubation method used in this study have the possibility for comprehending complex characteristic of Rs.

• Asian-Australasian Journal of Animal Sciences
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• 제12권8호
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• pp.1188-1191
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• 1999

Primordial germ cells (PGCs) of White Leghorn chicken embryos as a donor were transferred to Rhode Island Red chicken embryos as a recipient. At 48-50 h (stage 13-15) of incubation of fertilized eggs, donor PGCs, which were taken out from blood vessels of donor embryos, were injected into blood vessels of recipient embryos. Sex of the treated embryos was determined after the transfer of PGCs using remaining blood samples. In the present experiments, survival rate of the treated embryos was 33.3% for homo-sexual and 35.4% for hetero-sexual transfers of PGCs, respectively, when determined at 17 days of incubation. In this study, most of the treated embryos could not survive more than 18 days of incubation, though the reason for that was not clarified in the present work. The gonalds removed from embryos that died after 18 days of incubation and the organs from newly hatched chicks were examined for morphological and histological features. The gonads removed from the embryos with homo-sexual transfer of PGCs showed normal development in appearance. On the contrary, some (35.3%) of the embryos with hetero-sexual transfer of PGCs possessed abnormal gonads similar to ovotestis by histological observation. In cases where the gonads developed to be normal organs (64.7%) the sex of embryos was the same as recipient ones. The present results suggest that hetero-sexual transfer of the PGCs may bring about the possibility of development of the embryos bearing sexually different gametes, spermatogonia or oogonia.

• Journal of Microbiology and Biotechnology
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• 제22권1호
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• pp.126-132
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• 2012

A cellulose-degrading composite microbial system containing a mixture of microbes was previously shown to demonstrate a high straw-degrading capacity. To estimate its potential utilization as an inoculant to accelerate straw biodegradation after returning straw to the field, two cellulose-degrading composite microbial systems named ADS3 and WSD5 were inoculated into wheat straw-amended soil in the laboratory. The microbial survival of the inoculant was confirmed by a denaturing gradient gel electrophoresis (DGGE) analysis, whereas the enhancement of straw degradation in soil was assessed by measuring the mineralization of the soil organic matter and the soil cellulase activity. The results indicated that most of the DGGE bands from ADS3 were detected after inoculation into straw-amended autoclaved soil, yet only certain bands from ADS3 and WSD5 were detected after inoculation into straw-amended non-autoclaved soil during five weeks of incubation; some bands were detected during the first two weeks after inoculation, and then disappeared in later stages. Organic matter mineralization was significantly higher in the soil inoculants ADS3 and WSD5 than in the uninoculated controls during the first week, yet the enhanced degradation did not persist during the subsequent incubation. Similar to the increase in soil organic matter, the cellulase activity also increased during the first week in the ADS3 and WSD5 treatments, yet decreased during the remainder of the incubation period. Thus, it was concluded that, although the survival and performance of the two inoculants did not persist in the soil, a significant enhancement of degradation was present during the early stage of incubation.

• Asian-Australasian Journal of Animal Sciences
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• 제12권4호
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• pp.520-524
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• 1999

The present experiments were designed to examine whether exogenous DNA injected into the germinal crescent region (GCR) of early stage of developing embryos, which is considered to be the main place from which PGCs originate, can be transferred to recipient chicken embryos. In this experiment, Miw Z (DNA) dissolved in the transfection reagent (TR: Boehringer, Germany) was introduced into the GCR of donor embryos at stage 3-5 or 9-11, followed by continued incubation until the stage 13-15 of embryonic development. The PGCs collected from the embryonic blood vessels were examined for the incorporation of the injected DNA into the PGCs by the methods of X-gal staining and PCR analysis. As the results, the foreign DNA was successfully incorporated into the PGCS, leading to their transfer to the gonadal tissues. The present results, therefore, suggest that the early stage (3-5 or 9-11) of chicken embryonic development would be more successful than stage 13-15 in transferring exogenous genes to the recipient embryos, leading to the possibility of producing transgenic chicken medianting the PGCS.

• 한국패류학회지
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• 제9권2호
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• pp.1-15
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• 1993

The reproductive ecology of the purple shell, Rapana venosa was investigated by the histological observations on depositions of the egg capsules, and hatching of larvae in the laboratory and the subtidal zone of the vicinity of piung-do, Chollabud-do, west coast of korea, for one year from June 1992 to May 1993. The results are summarized as follows:1. Rapana venosa is dioecious in sex. The ovary is composed of a number of ovarian lobules, and the testis comprises a number of ovarian lobules, and the testis comprises of gonads could be classified into 4 stages in males and 5 stages in females: 1) growing stage(in female subdivided into 2 stages of early and late growing stage). 2)mature stage. 3)spent stage or copulationstage. 4)rdcovering stage. The early growing stage in females of the purple shell was in September through February, late gorwing stage was in October to March, mature stage was in September to January, mature stage was in September to July, copulation stage was in Februaty to June and recovering stage in April to October.3. Spawning occurred 3-4 times at intervals of 1-3 days, and completed within 10 days from the beginning of spawning during the spawning season of the year.4. From the results of laboratory and field observations, egg masses are composed of a number of egg capsules, egg masses are occurred from May to late August, and in mid August depositions of egg mass in composed of 90-113 egg capsules, fecundity in an egg capsule was ranged 984 to 1,241 eggs(average 1,096 egg). Therefore, fecundity in total egg capsules spawned per individual during the spawning season is estimated as approximately 320,000 to 450,000 egges.5. The incubation period during deposition of an egg capsule to hatching larvad tood 17 days at 18.3-20.4%C(water temperature)and 1.021 (specific gravity fo sea water).

• 대한수의사회지
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• 제16권4_5호
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• pp.193-198
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• 1980

The studies were under taken with the objective to observe water distribution and its content of developing embryo by dry method during the incubation periods. The results obtained were summarized as follows: 1. For the first time each developing embryoni

• Journal of Plant Biology
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• 제1권1호
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• pp.27-37
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• 1958

Durlng various experiments and investigations with antigrowth virus, I studied especially the infective and antiinfective process of it in small animals, and have got following results: 1. The rabbits are easily infected with this virus, having following five stages; incubation period of 2 to 3 days, stage of fever for 2 to 4 day, transient anemic stage, transient fcteric stage and stage of lasting iron-precipitation in the spleen. 2. According to the appearance of icteruis, I have divided the rabbits into following three groups, the first gorup, weighting less than 1000g, died after appearance of icterus, the second group, weighting 1000 to 1500 g. recoy ered after appearance of icterus, and the third group, weighting more than 1500 g. recovered without the appearance of jaundice. 3. In hematological study, marked decrease in R. B. C. and Hb were recognized but various leucocytes except lymphocytes slightly increased. 4. In pathological study, the spleen exhibited marked swelling with abundent blood and indistinct border between trabeculae and pulps at the initial stage of icterus and notable atrophy at the end stage of it. There are few iron-cells in the spleen histologically at the initial stage, but they increased in number with granuar appearance at the end stage. In the first group of rabbits above mentionel, the iron-cells increase suddenly with the death of animal and show diffuse precipitation of iron. The liver and indey have defferent aspects in proportion to icterus. If icterus appears, they show markel changes with turbidity and necrosis, but without icterus they present only slight changes. 5. The neutralining antibody is easily proved in the immunized rabbits for about one year. 6. The passive immunity has the defense immunability until 10\ulcorner 7. Gunia pigs are easily infected with this virus and get the immunity. On fowls this virus can be kept in the blood for about ten days by various inoculating methods, and the fowls obtain the defensive ability by reinoculation, but are unable to succeed this ability from generation to generation. 8. when young swine are infected with this virus, their growth are disturbed and result in atrophied swine. It is therofor presumed that the etiology of the antigrowth of these atrophied swine is similar morphological and functional changes observed in the above rabbits.

• 한국수정란이식학회지
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• 제7권2호
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• pp.81-88
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• 1992

Cryopreservation of mouse embryos biopsied at 4-cell stage was investigated by ultrarapid freezing. Four-cell embryos were obtained from ICR mice on 55h after hCG injection. Zona pellucida of the embryos were partially dissected with a cutting pipet, and then single blastomeres were biopsied from the embryos followed by incubation in $Ca^2$+ and $Mg^2$+-free M16 medium for 30min. Biopsied embryos cultured for lh or 15h were frozen by ultrarapid freezing method using 3M DMSO or 5M glycerol as a cryoprotectant, respectively. The developmental rate of biopsied embryos after ultrarapid freezing and thawing to blastocysts was 81 % in the group of biopsied embryos cultured for lb and 98% in the group of biopsied embryos cultured for 15h, respectively. When biopsied embryos after ultrarapid freezing and thawing were transferred to the uteri of pseudopregnant recipients, normal live young were born. These results suggest that this freezing method can efficiently cryopreserve biopsied mouse embryos.

• 대한의생명과학회지
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• 제10권3호
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• pp.305-308
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• 2004

We have examined alcohol-induced malformation of chick embryo. Alcohol was considered to induce the malformation of developing embryo and to have bad effects on embryonic stage. We injected alcohol into air sac on day 4 of incubation. Ten ％ alcohol-treated group showed a little decrease on their body length compared to the untreated group and distilled water-treated group. Thirty ％ alcohol-treated group showed significant decrease on their body length compared to the untreated group and 10％ ethanol treated group. In addition, we have observed malformation of eyeballs and bills. These results indicate that alcohol affects chicken developments and brings on malformation of developing stage.

• Journal of Microbiology and Biotechnology
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• 제26권9호
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• pp.1657-1660
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• 2016

Prion diseases are incurable neurodegenerative disorders. Our previous study demonstrated that polylysine was effective in prolonging the incubation period in a rodent model and in alleviating the scrapie prion protein (PrP^Sc) burden in the brain at the terminal stage of the disease. Here, we report that intraperitoneal administration of polylysine suppresses the accumulation of prions in the spleen during the early stages of the disease. This study supports the congruence of PrP^Sc inhibition by polylysine in both the spleen and brain.