• Korean Journal of Soil Science and Fertilizer
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• v.45 no.6
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• pp.1120-1125
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• 2012

To assess fertilizer value of an quasi-aerobically fermented liquid clipped-grass fertilizer, aerobic incubation experiment using two texturally contrasting loam (L) and sandy loam (SL) soils was conducted for 60 days to investigate temporal variations in N mineralization pattern of the liquid fertilizer applied. To do so, the quasi-aerobically fermented liquid clipped-grass fertilizer was prepared, applied to each soil at a rate of 200 kg-N $ha^{-1}$ and aerobically $25^{\circ}C$ in the dark. During incubation, soil water content was adjusted to field moisture capacity (-33 kPa of soil matric potential) by adding distilled water as necessary to maintain their initial weights. At desired time of incubation (0, 1, 5, 10, 20, 40, and 60 days after incubation), soil was sampled and analyzed for inorganic nitrogen ($NH_4{^+}$-N and $NO_3{^-}$-N) concentrations, pH, EC, total carbon contents and total nitrogen contents. Concentrations of $NH_4{^+}$-N began to decrease right after incubation for L soils, and 10 days after incubation for SL soils, while those of $NO_3{^-}$-N began to increase onset of $NH_4{^+}$-N disappearance. The results of this study showed that quasi-aerobically fermented liquid clipped-grass fertilizer could serve as an alternative to chemical N fertilizer.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.664-670
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• 2012

Experiments were conducted to find out the landscape effects and green manure production at the same time in farmland. Cornflower was grown in different soil texture with sand, sandy loam, loam, clay loam, and was sowing with autumn and spring respectively. The overwintering rate of cornflower was at 58.7% in average, and the treatment at sand soil showed 62.1% that was highest among other soils, which cornflower is possible to winter landscape crop. After flowering of cornflower, the contents of total nitrogen (T-N) and total carbon (T-C) in plant were 15.0 and $409.2g\;kg^{-1}$, respectively, and the carbon-nitrogen ratio (C/N) was 28.6. The yield of cornflower biomass, which will be returned to soil as green manure, recorded $1,210{\sim}3,920kg\;ha^{-1}$ at the spring seeding higher than the autumn seeding as $1,540{\sim}3,170kg\;ha^{-1}$, and the biomass treated by soil texture were showed that the treatments at the clay loam had been the largest yields both spring and autumn seeding among at other treatment of soil. The heights of cornflower regardless of soil treatments were 52.8 to 73.6 cm at the autumn seeding and 35.5 to 79.2 cm at the spring seeding although it was more significant variation at the soil textures than the seeding periods. The flowering periods of cornflower ranged from $17^{th}$ to $20^{th}$ in May at the autumn seeding and from $19^{th}$ to $20^{th}$ in June at the spring seeding, which was faster 30 days approximately at the autumn seeding than the spring seeding. In a view of the cornflower application as green manure after flowering, the autumn seeding, when considered to combine with following crops, was more suitable and various than the spring seeding, even though the yield at spring seeding was higher than one at autumn seeding.

• Development and Reproduction
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• v.9 no.2
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• pp.95-103
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• 2005

Reproductive cycle, gonadosomatic index(GSI), egg diameter composition, first sexual maturity, sexually matured length(50% of first sexual maturity), and sex ratio of Amusium japonicum japonicum, were investigated by histological observations and morphometric data. Samples were collected monthly from the subtidal zone of Sogwipo, Jejudo, Korea, for two years. The sun and moon scallop Amusium japonicum japonicum is dioecious. Monthly variation in the GSI showed similar patterns with the reproductive cycle. Ripe oocytes were about $70{\sim}90\;{\mu}m$ in diameter and had thick egg membranes. The spawning period was from November to January, and the main spawning occurred between November and December when the seawater temperature was relatively low. From monthly changes in egg diameter composition, the spawning period was once a year, although the number of spawning frequencies is assumed to occur more than twice during the spawning season. The reproductive cycle of this species could be divided into five successive stages: early active stage(April to June), late active stage(June to September), ripe stage(October to November), spawning stage(November to January), and spent/resting stage(February to April). First sexual maturities in female and male scallops ranging from 85.1 to 90.0mm in shell length were over 50% and they were 100% for scallops over 90.0mm in shell length. In this population, sexually matured shell lengths(50% of rate of group maturity) in females and males were 86.96 and 86.59mm, respectively. The female to male sex ratio among individuals over 85.1mm in shell length was not significantly different from 1:1($X^2=0.18$, p>0.05). No evidence of hermaphrodite was found in histological sections of any scallop examined.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.2
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• pp.129-139
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• 2002

Fish distribution characteristics are essential to assess and estimate fisheries resources in a particular area. The primary goal of this study is to determine the distribution characteristics by the bottom trawling in the Yellow Sea west of South Korea. The surveys were carried out between 33$^{\circ}$00'N~37$^{\circ}$00'N latitude and 124$^{\circ}$00'E~126$^{\circ}$00'E longitude at EEZ(Exclusive Economic Zone) of Korea in Yellow Sea on May and August, 1999 and April, 2000. The ships used in this survey were the R/V Chung-kyeong(G/T 300) and R/V Dong-baek(G/T 1,050) of Yeosu National University. The results obtained can be summarized as follows 1. From the trawl data the fisheries resources are seriously decreasing through most of the species(about more 50%) have been appeared only one time at the bottom trawl on April, 2000. The total fish species caught by the trawl net during the 3 times survey were 106 species and a few species(dominant species) of these occupied 50~90% of the quantity of the total quantity by number or by weight. Among the dominant species the tanaka's snailfish was recorded to be the most dominant species in the survey area. The fish species in the Yellow Sea were clustered according to the regions. They clustered in two or three partes to the south-north direction in the spring season and clustered in two parts to the on-off shore direction of the shore in the summer season. Most of the fish caught at the the trawl net with cover-net(30.3mm) were small sized. They were shorter than 15 cm in length and the extruding rate of the cod-end which was 60mm mesh size ranges about 90%. 2. The densities of the number and weight per unit volume derived from the total catches sampled in April, 2000 survey were $1532.2{\times}10^{-6}fish/m^3$ and $39.55{\times}10^{-6}kg/m^3$, respectively. 3. The density variation of fish population between 1999 and 2000 showed a slight tendency to increase.

• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.240-246
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• 2007

To evaluated the effect of low temperature storage on quality of fresh shoot of Sedum sermentosum, weight loss, Hunter L, a and b value, chlorophyll, water content, and general appearance were investigated during storage at 20, 10, and $5^{\circ}C$. Just after harvesting, fresh shoots ($10{\pm}2cm$ length) were stored with wrap film (linear LDPE)-packaged condition using the Styrofoam dish ($20{\times}10cm$, which 40 fresh shoots per dish). The fresh weight of 40 shoots was gradually decreased according to days after storage and higher storage temperature. The weight loss of fresh shoots showed significant difference (8.7-25.3%) between just before storage and 10 days after storage, and the degree of weight loss was more severer in higher storage temperature. Wanju local strain showed the lowest weight loss, and the most severe case was Pohang local strain. SPAD value related to chlorophyll content was rapidly decreased after 4 and 6 days at 20 and $10^{\circ}C$ storage, respectively. It was slowly decreased according to days after storage at $5^{\circ}C$. Yellowish color in bottom leaves of shoot appeared after 4, 6 and 8 days at 20, 10, and $5^{\circ}C$ storages, respectively. Hunter L and a values were gradually increased after storage, and it showed significant difference between just before storage and 10 days after storage. The total rate of discoloration over 50% or decay shoot was largely increased as higher temperature. It was significantly correlated to the water content of fresh shoot among local strains $(P{\leq}0.01)$. The freshness of shoot after storage was maintained in order of Wanji, Gunsan, Wando and Pohang local strain. The results indicated that the freshness was maintained for 8 days after $5^{\circ}C$ storage, when the fresh shoot was stored with wrap film-packaged condition.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.11
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• pp.1619-1637
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• 2000

A review was undertaken to obtain information on the range of beak-trimming methods available or under development. Beak-trimming of commercial layer replacement pullets is a common yet critical management tool that can affect the performance for the life of the flock. The most obvious advantage of beak-trimming is a reduction in cannibalism although the extent of the reduction in cannibalism depends on the strain, season, and type of housing, flock health and other factors. Beak-trimming also improves feed conversion by reducing food wastage. A further advantage of beak-trimming is a reduction in the chronic stress associated with dominance interactions in the flock. Beak-trimming of birds at 7-10 days is favoured by Industry but research over last 10 years has shown that beak-trimming at day-old causes the least stress on birds and efforts are needed to encourage Industry to adopt the practice of beak-trimming birds at day-old. Proper beak-trimming can result in greatly improved layer performance but improper beak-trimming can ruin an other wise good flock of hens. Re-trimming is practiced in most flocks, although there are some flocks that only need one trimming. Given the continuing welfare scrutiny of using a hot blade to cut the beak, attempts have been made to develop more welfare friendly methods of beak-trimming. Despite the developments in design of hot blade beak-trimmers the process has remained largely unchanged. That is, a red-hot blade cuts and cauterises the beak. The variables in the process are blade temperature, cauterisation time, operator ability, severity of trimming, age of trimming, strain of bird and beak length. This method of beak-trimming is still overwhelmingly favoured in Industry and there appears to be no other alternative procedures that are more effective. Sharp secateurs have been used trim the upper beak of both layers and turkeys. Bleeding from the upper mandible ceases shortly after the operation, and despite the regrowth of the beak a reduction of cannibalism has been reported. Very few differences have been noted between behaviour and production of the hot blade and cold blade cut chickens. This method has not been used on a large scale in Industry. There are anecdotal reports of cannibalism outbreaks in birds with regrown beaks. A robotic beak-trimming machine was developed in France, which permitted simultaneous, automated beak-trimming and vaccination of day-old chicks of up to 4,500 chickens per hour. Use of the machine was not successful because if the chicks were not loaded correctly they could drop off the line, receive excessive beak-trimming or very light trimming. Robotic beak-trimming was not effective if there was a variation in the weight or size of chickens. Capsaicin can cause degeneration of sensory nerves in mammals and decreases the rate of beak regrowth by its action on the sensory nerves. Capsaicin is a cheap, non-toxic substance that can be readily applied at the time of less severe beak-trimming. It suffers the disadvantage of causing an extreme burning sensation in operators who come in contact with the substance during its application to the bird. Methods of applying the substance to minimise the risk to operators of coming in contact with capsaicin need to be explored. A method was reported which cuts the beaks with a laser beam in day-old chickens. No details were provided on the type of laser used, or the severity of beak-trimming, but by 16 weeks the beaks of laser trimmed birds resembled the untrimmed beaks, but without the bill tip. Feather pecking and cannibalism during the laying period were highest among the laser trimmed hens. Currently laser machines are available that are transportable and research to investigate the effectiveness of beak-trimming using ablasive and coagulative lasers used in human medicine should be explored. Liquid nitrogen was used to declaw emu toes but was not effective. There was regrowth of the claws and the time and cost involved in the procedure limit the potential of using this process to beak-trim birds.

• The Korean Journal of Physiology
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• v.25 no.2
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• pp.189-200
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• 1991

During the past few years it has been proposed that lithium clearance can be used as a reliable measure for the outflow of tubular fluid from the proximal tubule. This study was aimed to characterize the inflow dependent reabsorption of Na in renal tubule beyond the proximal tubule. For this purpose, lithium clearance was used as a measure for the inflow from the proximal tubule and the changes in reabsorption fraction of Na and water were determined in rabbits. Rabbits were pretreated with hypotonic saline solutions for an hour (50 mM/L NaCl, 20 ml/hr/kg). And then a hypertonic solution of 500 mM/L NaCl (20 ml/kg) was administered intraperitoneally in conjunction with a bolus of LiCl solution (2 mM/kg, i.v.) for conditioning the $C_{Li}$ and urine flow rate. To rule out the effect of $Li^+$ on tubular functions, a bolus of NaCl solution (2 mM/kg, i.v.) was administered. Fifteen, thirty, and sixty minutes after injection of hypertonic saline arterial blood and urine samples were taken. Urinary and plasma concentrations as well as urinary output of $Li^+,\;Na^+\;and\;K^+$ were measured. From these $C_{Li},\;C_{Na}$ and the reabsorption fraction of Na and water $(Fr_{Na}\;&\;FrH_2O)$ were calculated. These results were compared with those from control groups in which the same amount of isotonic saline (145 mM/L NaCl) and of 15% dextran solution were administered in the same way as that in experimental group. Followings are the results obtained. 1) The plasma concentration of $Na^+$ in rabbits injected with hypertonic saline reached the peak value after 15 min and thereafter no significant change was observed. Hematocrit values did not show any change, while urinary excretion of $Na^+$ increased markedly during the first 15 min and decreased thereafter. These results were not affected by an injection of a small amount of LiCl. 2) The clearances of $Li^+,\;Na^+\;and\;K^+$ in rabbits injected with hypertonic saline and LiCl solution decreased. 3) In spite of the variation in $C_{Li},\;Fr_{Na}$ did not show any significant change while $FrH_2O$ increased gradually. 4) $C_{Li}$ decreased also in rabbits received isotonic saline. $Fr_{Na}$ tended to be higher than that in hypertonic saline group, while $FrH_2O\;and\;Fr_{Na}$ did not associated with the decrease in $C_{Li}$. 5) $C_{Li}$ of the rabbits received dextran solution fluctuated persistently and $Fr_{Na}\;and\;FrH_2O$ did not change in along with $C_{Li}$ although $Fr_{Na}$ had a tendency to be higher than that in hypertonic saline group. 6) From the above results it was concluded that: (a) In rabbits with normal body store of $Na^+$, the $Fr_{Na}$ of renal tubule beyond proximal tubule. calculated from $C_{Li}$ as a measure of inflow from proximal tubule is constant in spite of variations in $C_{Li}$. (b) The $FrH_2O$ calculated from $C_{Li}$ is dependent largely upon ADH rather than inflow from proximal tubule. (c) When there is a decrease in plasma $Na^+$ concentration or ineffective body fluid. $Li^+$ reabsorption may occur in the thick segnent of Henle's loop and hence the determination of $Fr_{Na}$ and $FrH_2O$ will not be easy one, but $Fr_{Na}$ is constant under the same experimental conditions.

• The Korean Journal of Physiology
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• v.2 no.1
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• pp.23-30
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• 1968

Tissue homogenates of 12 kinds of human cancer tissues were incubated separately in medium containing $C^{14}-1-glucose$ and $C^{14}-6-glucose$ as a substrate in order to observe the oxidative pathway of glucose in the tumor tissues. At the end of 3 hours incubation in the Dubnuff metabolic shaking incubator, respiratory $CO_2$ samples trapped by alkaling which was placed in the center well of incubation flask were analysed for total $CO_2$ production rates and their radioactivities. The tissue homogenate samples after incubation were analyzed for their concentrations of glucose, lactate and pyruvate. Calculations were made on the glucose consumption rate and accumulation rates of lactate and pyruvate. Fractionation of oxidative pathway of glucose was carried out by calculating $C^{14}O_2 yields from C-1 and C-6 carbon of glucose. The following results were obtained. 1. In 12 kinds of human cancer, total $CO_2$ production rates were less than $8{\mu}M/gm$ except 2 cases. These lower values impressed that oxidative metabolism in the tumor tissues generally inhibited as compared with that in normal tissues. On the other hand, fractions of $CO_2$ derived from glucose to total $CO_2$ production rates (RSA) were less than 10% in every case. These facts showed that oxidation of glucose into $CO_2$ was remarkably inhibited in the tumor tissues. 2. Factions of glucose disappeared into $CO_2\;(RGD_{CO_2})$, lactate $(RGD_L)$, pyruvate $(RGD_P)$ to glucose consumption rates were as follows. $RGD_{CO_2}$ were less than 2% in cases of in this experiment and $RGD_L$ showed more than 5% except in 2 cases. These facts showed that anaerobic degradation of glucose into 3 carbon compounds was easily proceeded but further degradation into $CO_2$ via the TCA cycle was greatly inhibited resulting in accumulation of lactate. There are large variation in values of $RGD_P$ in different kinds of tumor tissue but relatively higher values in $RGD_{CO_2}$ were obtained in the tumor tissues as compared with those of normal tissues. 3. The oxidative pathway of glucose in tumor tissues were analyzed from the values of RSA which were obtained in $C^{14}-1\;and\;C^{14}-6-glucose$ incubation experiments. It was found that 3% of $CO_2$ derived from glucose were oxidized via the principal EMP-TCA cycle and the remainder were via alternate pathway such as HMP in the liver cancer and values in other cancer tissues were as follows; 4% in the tongue cancer, 6% in the colon cancer, 6% in the lung cancer, 9% in the stomach cancer, 11% in the ovarian cancer, 12% in the neck tumor, 22% in the uterine cancer, 22% in the bladder tumor, 32% in the spindle cell sarcoma and 65% in the brain tumor. These values except later 2 cases showed less than 30% which is the lowest value among the normal tissues. Even in the brain tumor in which showed highest value in the tumor group. It is reasonable to suppose that this fraction was remarkably decreased because values in normal brain tissue was more than 90%. From the above data, it was concluded that in tumor tissues, oxidation of glucose via TCA cycle was greatly inhibited but correlation between degree of inhibited oxidation of glucose via TCA cycle and malignancy of tumor were not clarified in this experiments.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.3
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• pp.222-229
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• 2009

This study was performed to evaluate effect of different fertilization management practices on soil microbial activities and community structure using soil enzyme activities and PLFA contents in volcanic ash citrus orchard soil. Six experiment plots have differently managed based on the recommended application rate(NPK) of chemical fertilizer and compost for 13 years. Experiment plots were composed of no-fertilization(control), compost only, half amount of NPK with compost (1/2NPK+COM), NPK, NPK with compost(NPK+COM), and 3 times amount of NPK(3NPK). Soil samples collected in early March, May, July, and September 2007. Urease activity was high at NPK+COM in March, May, and September. It was higher in NPK+COM than in NPK. Urease activity decreased according to the order NPK>compost>control in March and May; compost>NPK>control in July and September. Dehydrogenase activity was significantly higher in 1/2NPK+COM($4.3ug\;TPF\;g^{-1}\;24h^{-1}$) than in control($2.4ug\;TPF\;g^{-1}\;24h^{-1}$), May. $\beta$-glucosidase activity was significantly higher in NPK and 1/2NPK+COM than in control, May. In March, Total PLFA contents were higher in NPK+COM($349.2n\;mol\;g^{-1}$) than in 3NPK($228.5n\;mol\;g^{-1}$). And that were higher in 1/2NPK+COM($237.8n\;mol\;g^{-1}$) than in 3NPK($133.1n\;mol\;g^{-1}$), May. Distribution ratio of soil microbial groups by PLFA biomaker were not significantly difference in between seasonal and treatments. Principal component analysis by PLFA profiles showed that microbial community in compost and 3NPK plot were different compared with other treatments in March. But Differences in compost and 3NPK plot were not found in May. Our result showed that the change of microbial community structure affected by fertilization effect and seasonable variation.

• Korean Journal of Agricultural Science
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• v.2 no.2
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• pp.331-339
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• 1975

This experiment was carried out to obtain some imformations about the ecological variations of the heading time of the newly breeded Indica x Japonica varieties/pedigrees according to the seasonal changes of the seeding date. day length and temperature. The results obtained are summarized as follows; 1) At all varieties. days to heading showed a straight reduction according as the seeding time was delayed. 2) At the group of Japonica varieties. the days to heading of early maturing varieties were much shortened and that of medium or late maturing varieties were little or not shortened under high temperature condition but at the group of Indica ${\times}$ Japonica va rieties/pedigrees. days to heading were significantly elongated under high temerature condition. 3) At the group of Japonica varieties. the effect of the short day condition on the days to heading was significantly high at the medium and the late maturing varieties than at the early maturing varieties. however. the short day effect on the reduction of days to heading was not related with the earlyness of each varieties at the group of Indica ${\times}$ Japonica varieties/pedigrees. 4) Days to heading of all varieties under the high temperature condition were longer than that under the ordinary culture. On the other hand, the days to heading of Japonica varieties under the short day treatment were shorter than the days to heading of ordinary culture but at the group of Indica x Japonica varieties/pedigrees. the days to heading under the short day treatment were longer than ordinary culture. 5) At both varieties groups. the days to heading at each seeding time were significantly correlated with days to heading at ordinary cultivation. fl) At the group of Japonica varieties. relatively high correlation(p=0.1) was recognized between the days to heading by delay of seeding time, but at the group of Indica ${\times}$ Japonicava rieties/pedigrees, correlation between the ordinary heading date and the shortening rate of days to heading was very low.