• Fisheries and Aquatic Sciences
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• v.22 no.11
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• pp.25.1-25.9
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• 2019

Background: Due to the continuous demand for fish coupled with decline in capture fisheries, there is the need to increase aquaculture production to meet the demand. Aquaculture is faced with high cost of feeding since fish oil and fish meal are expensive. In view of this, there are calls to explore alternatives that are cheap and reliable. Objectives: This study on Oreochromis niloticus was conducted to evaluate the effects of replacing fish oil (FO) with palm oil (PO) at 0%, 25%, 50%, 75%, and 100% on muscle fatty acid and proximate composition as well as growthrelated enzyme activities and mRNA expression. Methods: Oreochromis niloticus were fed five experimental diets (33% crude protein and 10% crude lipid) for 8 weeks. Feed had variation in fish oil and palm oil contents. After the 8 weeks feeding trial, five fish were sampled from each tank (15 from each treatment) and euthanized using an excess dose of tricaine methane sulfonate (MS-222 at 200 mg/L). Fatty acid and enzyme activities were analyzed using standard protocols. Also, RT-qPCR was used to quantify the expression levels of selected growth-related genes. Results: Fish fed 25% PO recorded the least muscle protein content and was significantly lower than the group fed 100% PO. Paired box protein 7 (Pax-7) enzyme activity was significantly higher in the group fed 50% PO compared to the groups fed 25% PO and 100% PO, while caplain-3 (Capn-3) was significantly lower in the group fed 0% PO compared to all other groups. There was a significant difference among treatments with respect to mRNA expression of Pax-7 and Capn-3. Group fed 25% PO had significantly lower mRNA expression of Pax-7, while the group fed 75% PO recorded significantly higher mRNA expression of Capn-3 compared to groups fed 0% PO, 25% PO, and 100% PO. Pearson's correlation analysis revealed that Igf-I and Igf-II mRNA expression have significant correlation with n-3 polyunsaturated fatty acids content in muscle. Conclusion: The results suggest muscle protein content could be modified if FO is replaced with PO. Also, mRNA expression of Pax-7 and Capn-3 is affected by replacing FO with PO.

• Journal of Ecology and Environment
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• v.42 no.2
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• pp.85-89
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• 2018

Observations and video documentation of interactions between animals living in dens, cavities, and other enclosed spaces are difficult, but they play an important role in field biology, ecology, and conservation. For example, bird parents visiting nests and feeding their nestlings may provide crucial information for testing of ecological hypotheses and may easily attract attention of participants of citizen-science ecological and conservation projects. Because of the nest concealment of cavity-nesting birds, their behaviors in the nest can only be studied by using video surveillance. Professional wildlife surveillance systems are extremely expensive. Here, we describe an inexpensive video setup that can be constructed with relatively little effort and is more affordable than any previously described system. We anticipate that the relatively low cost of about 250 USD for a battery-operated system is an important feature for citizen-science type of projects and for applications in heavily populated areas where the potential for theft and vandalism may be high. Based on our experiences, we provide methodological advice on practical aspects of using this system in the field for ecological research on birds. We highlight the low cost, easiness of construction, and potential availability to a large number of observers taking part in wildlife monitoring projects, and we offer technical help to participants of such research projects.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.2
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• pp.31-40
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• 1999

Characteristics of monopole antenna and planar conductor structure mounted on handheld telephone are anlayzed by using FDTD method. Feeding of monopole antenna is implemented with lumped elements and plastic case is coated on the surface of conductor box. Otherwise, resonant frequency of handheld telephone mounting monopole antenna with no plastic case is 877MHz, when plastic case (${\varepsilon}_r=2$) is coated, the resonant frequency is down to 82MHz and the bandwidth is broadened about 1.5 times. Planar structure of handheld telephone mounted on the body makes to change far-field gain radiation patterns. In this case, radiation patterns are somewhat asymmetrical. Handheld telephone using PIFA(Planar Inverted F Antenna), instead of monopole antenna, is resonated at frequency 1.52GHz that is available onPCS. In the radiation pattern of this structure, azimuth that electric field intensity is presented below 20dB is 14$^{\circ}$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.9
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• pp.1023-1029
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• 2010

In this paper, we proposed the broadband polarization diversity antenna operating in the PCS, WCDMA and WiBro band for mobile base station. We designed the antenna using the dipole antenna of the square loop type and microstrip feeding structure. Additionally, we used the choke box to remove the distortion of radiation patterns by the reflector structure when operating broadband. The simulation was performed using MWS in a commercial tool of CST company and the antenna was fabricated on a teflon substrate with 3.33 of the relative permittivity. The proposed antenna has the bandwidth of 640 MHz(from 1.75 to 2.39 GHz) when VSWR is below 1.5. At the operating bands, the interisolation between the cross-pair radiators is less than -25 dB and the maximum gains for PCS, WCDMA and WiBro band are 8.9, 8.2 and 8.6 dBi, respectively.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.11
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• pp.1659-1664
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• 2008

To study the working mechanisms for non-starch polysaccharidases to improve the growth performance of broiler chickens, a 21-day feeding trial was conducted. Two dietary treatments were included: 1) wheat diet (the control); 2) wheat+xylanase diet (xylanase, Allzyme PT, Alltech, Kentucky, USA). There were 8 replicates with 8 birds each for each treatment and the experimental diets were given to birds from hatch. Feed intake and body weight were measured on days 7 and 21. At the same ages, samples were taken for the determination of selected groups of luminal and mucosa-associated bacteria, mucosal morphology, brush-border membrane (BBM) bound enzyme activity and ileal nutrient digestibility. The xylanase supplement increased (p<0.05) body weight gain (BWG) and improved feed conversion ratio (FCR) at the end of the experiment but protein and starch digestibilities were not affected (p>0.05) by xylanase. Up to day 7, xylanase increased the counts of C. perfringens in the ileum and total anaerobic bacteria (TAB) in the caeca (p<0.05, p=0.07, respectively). By day 21, the counts of ileal lactobacilli (p<0.05) and TAB (p=0.07) were lower in birds given the xylanase-supplemented diet than in those on the control diet. No significant differences were observed in the counts of mucosa-associated lactobacilli and coliforms between xylanase treatment and the control at both ages. Villus height at the jejunum was not affected (p>0.05) by the supplement but crypt depth at the same site was reduced at day 7. Also, xylanase tended to increase the concentration of BBM protein (p = 0.09) and the specific activity of sucrase (p = 0.07) at day 21.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.1
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• pp.92-96
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• 2003

The on-site sewage sludge vermicomposting equipment was designed and evaluated on the batch and continuous tests. The vermicomposting equipment was designed to consider the mechanization as well as automation. In terms of performance evaluation of equipment with continuous experiments, the highest treatment rate was found in the condition of 5mm in particle size and 10mm in e feeding height. Also, 20~25kg of earthworm per 50kg of sewage sludge was the most appropriate density of earthworm. In addition, the most effective separation of cast was found when the earthworm breeding box height was 80cm. The performance evaluation on equipment allowed the establishment of earthworm composting capacity of 2ton per a day with a size of $5{\times}3{\times}1m$ and the automatic control devices.

• Journal of Sericultural and Entomological Science
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• v.16 no.2
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• pp.1-34
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• 1974

These experiments pertain to various factors influencing the quantitative characters of cocoon crops in summer and early autumn seasons. Initially, in order to establish the possible ways of the silkworm rearing more than three times a year in Korea, the author attempted to get further information about the various factors affecting the cocoon crop in every silkworm rearing season. The trials were conducted eleven times a year at four places for three years. The field trial was conducted with 19 typical sericultural farmers who had been surveyed. At the same time the author statistically analyzed the various factors in close relation to tile cocoon crop in autumn season. The effect of guidance on 40 sericultural farmers was analyzed, comparing higher level farmers with lower level farmers ; and the author surveyed 758 non-guided farmers near the guided farmers during both spring and autumn seasons. In addition, another trial on the seasonal change of leaf quality was attempted with artificial diets prepared with leaves grown in each season. It was found that related factors to cocoon crops in summer and early autumn seasons appeared to be leaf quality, and temperature for young and grown larvae. A 2$^4$ factorial experiment was designed in summer season, and another design with one more level of varied temperature or hard leaf added to a 24 factorial experiment was conducted in early autumn. The experimental results can be summarized： 1. Study on the cocoon crops in the different rearing seasons 1) It was shown that earlier brushing of silkworm generally produced the most abundant cocoon crop in spring season, and earlier or later than the conventional brushing season, especially earlier brushing was unfavorable for the abundant cocoon crop in autumn season. 2) The cocoon crop was affected by the rearing season, and decreases in order of sire with spring, autumn, late autumn, summer and early autumn seasons. 3) It was Proved that ordinary rearing and branch rearing were possibles 4 times a year ; in the 1st, 3rd, 8th, and 10th brushing season. But the 11th brushing season was more favorable for the most abundant cocoon crop of branch rearing, instead of the 10th brushing season with ordinary rearing. 2. Study on the main factors affecting the cocoon crop in autumn season 1) Accumulated pathogens were a lethal factor leading to a bad cocoon crop through neglect of disinfection of rearing room and instruments. 2) Additional factors leading to a poor cocoon crop were unfavorable for rearing temperature and humidity, dense population, poor choice of moderately ripened leaf, and poor feeding techniques. However, it seemed that there was no relationship between the cocoon crop and management of farm. 3) The percentage of cocoon shell seemed to be mostly affected by leaf quality, and secondarily affected by the accumulation of pathogens. 3. Study on the effect of guidance on rearing techniques 1) The guided farms produced an average yearly yield of 29.0kg of cocoons, which varied from 32.3kg to 25.817g of cocoon yield per box in spring versus autumn, respectively. Those figures indicated an annual average increase of 26% of cocoon yield over yields of non-guided farmers. An increase of 20% of cocoon yield in spring and 35% of cocoon yield in autumn were responsible. 2) On guided farms 77.1 and 83.7% of total cocoon yields in the spring and autumn seasons, respectively, exceeded 3rd grade. This amounted to increases of 14.1 and 11.3% in cocoon yield and quality over those of non-guided farms. 3) The average annual cocoon yield on guided farms was 28.9kg per box, based on a range of 31.2kg to 26.9kg per box in spring and autumn seasons, respectively. This represented an 8% increase in cocoon yield on farms one year after guidance, as opposed to non-guided farms. This yield increase was due to 3 and 16% cocoon yield increases in spring and autumn crops. 4) Guidance had no effect on higher level farms, but was responsible for 19% of the increases in production on lower level farms. 4. Study on the seasonal change of leaf quality 1) In tests with grown larvae, leaves of tile spring crop incorporated in artificial diets produced the best cocoon crop; followed by leaves of the late autumn, summer, autumn, and early autumn crops. 2) The cocoon crop for young larvae as well as for grown larvae varied with the season of leaf used. 5. Study on factors affecting the cocoon crops in summer and early autumn A. Early autumn season 1) Survival rate and cocoon yield were significantly decreased at high rearing temperatures for young larvae 2) Survival rate, cocoon yield, and cocoon quality were adversely affected by high rearing temperatures for grown larvae. Therefore increases of cocoon quantity and improvement of cocoon quality are dependent on maintaining optimum temperatures. 3) Decreases in individual cocoon weight and longer larval periods resulted with feeding of soft leaf and hard leaf to young larvae, but the survival rate, cocoon yield and weight of cocoon shell were not influenced. 4) Cocoon yield and cocoon quality were influenced by feeding of hard leaf to grown larvae, but survival rate was not influenced by the feeding of soft leaf and hard leaf. 5) When grown larvae were inevitably raised at varied temperatures, application of varied temperature in the raising of both young and grown larvae was desirable. Further research concerning this matter must be considered. B. Summer season 1) Cocoon yield and single cocoon weight were decreased at high temperatures for young larvae and survival rate was also affected. 2) Cocoon yield, survival rate. and cocoon quality were considerably decreased at high rearing temperatures for grown larval stages.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.12
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• pp.558-569
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• 2020

This study examined the frequency of a broiler's stay in each area as stock density using an ICT-based image analysis technique from the perspective of precision livestock farming (PLF) according to the increase in the domestic broiler farms to understand the normal behavior patterns of broilers by age. The broiler was used in the experimental box (3.3×2.7 m) in a poultry house in Gyeonggi province. The stock densities were 9.5 birds/㎡ (n=85) and 19 birds/㎡ (n=170), respectively, and the frequency of stay by feeding, water, and rest area was monitored using a top-view camera. The image data of three-colored-specific broilers identified as the stock density were acquired by age (12, 16, 22, 27, and 29 days) for six hours. In the collected image data, the object tracking technique was used to record the cumulative movement path by connecting approximately 640,000 frames at 30 fps to quantify the frequency of stay in each area. In each stock density, it was significant in the order of the rest area, feeding, and water area (p<0.001). In 9.5 birds/㎡, it was at 57.9, 24.2, and 17.9 %, and 73.2, 16.8, and 10 % in 19 birds/㎡. The frequency of a broiler's stay could be evaluated in each area as the stock density using an ICT-based image analysis technique that minimizes stress. This method is expected to be used to provide basic material for developing an ICT-based management system through real-time monitoring.

• The Korean Journal of Pesticide Science
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• v.20 no.2
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• pp.152-158
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• 2016

The cause of death was investigated with several dead cabbage moth larvae in breeding box. Bacterial strains were isolated and selected from the dead larvae by bioassay. One of them was identified as Serratia marcescens used by morphological characteristics and gene sequencing. S. marcescens were cultured by Luria Bertani (LB) media broth for bioassay. When 100-fold dilution of culture broth to third larvae of diamondback moth, Plutella xylostella, it was showed a 100% mortality at 2 days after treatment, and only 10-fold dilution of supernatant liquid was showed 86.6% mortality. When the culture broth of S. marcescens was applied to the larvae of beet armyworm, Spodoptera exigua, contact and feeding toxicity were 20 and 8% of mortality, respectively. Otherwise, when the culture broth of S. marcescens was applied to 5 major plant pathogens, antibacterial activities against Fusarium oxysporum, Rhizoctonia solani, Colletotrichum gloeosporioides, Phytophthora capsici and Sclerotinias clerotiorum were 4.7, 11.3, 20, 15.7 and 42.6%, respectively. Also, degradation ability of S. marcescens against protein and chitin were examined.

• Journal of the Korea Organic Resources Recycling Association
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• v.4 no.2
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• pp.77-85
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• 1996

The study on the ripening of leather waste sludge was performed to vemistabilize the sludge effectively using a laboratory scale darkened wood box reactor ($10{\times}10{\times}20cm$). The acceptable feed conditions for earthworm of Eh, alkalinity were obtained in the 30th and 35th days, respectively. The value of pH was gradually decreased from 7.8 to 7.1 through the ripening time. The contents of heavy metals of the ripened sludge were estimated as lower levels compared to the other regulatory standards for compost. After the ripening time for 50days, the physico-chemical properties of the sludge were estimated as pH 7.1, water content 72%, redox potential 85mV, electrolytic conductivity $2,620{\mu}mhos/cm$ and alkalinity 450 ppm as $CaCO_3$, respectively. In the ripened sludge, survival rate of the earthworms for 50 days was about 75%, and the live weight increase rate was about 230% at the temperature range of $20{\sim}25^{\circ}C$. Moreover, hatching rate of the earthworm cocoons was about 87% and the highest value was obtained in the 20~30th days. From the above results, it was evaluated that leather waste sludge could be vermistabilized effectively by earthworms, when the sludge was ripened during 50 days.