• Asian-Australasian Journal of Animal Sciences
• /
• v.25 no.6
• /
• pp.772-784
• /
• 2012

Marker-assisted gene pyramiding aims to produce individuals with superior economic traits according to the optimal breeding scheme which involves selecting a series of favorite target alleles after cross of base populations and pyramiding them into a single genotype. Inspired by the science of evolutionary computation, we used the metaphor of hill-climbing to model the dynamic behavior of gene pyramiding. In consideration of the traditional cross program of animals along with the features of animal segregating populations, four types of cross programs and two types of selection strategies for gene pyramiding are performed from a practical perspective. Two population cross for pyramiding two genes (denoted II), three population cascading cross for pyramiding three genes(denoted III), four population symmetry (denoted IIII-S) and cascading cross for pyramiding four genes (denoted IIII-C), and various schemes (denoted cross program-A-E) are designed for each cross program given different levels of initial favorite allele frequencies, base population sizes and trait heritabilities. The process of gene pyramiding breeding for various schemes are simulated and compared based on the population hamming distance, average superior genotype frequencies and average phenotypic values. By simulation, the results show that the larger base population size and the higher the initial favorite allele frequency the higher the efficiency of gene pyramiding. Parents cross order is shown to be the most important factor in a cascading cross, but has no significant influence on the symmetric cross. The results also show that genotypic selection strategy is superior to phenotypic selection in accelerating gene pyramiding. Moreover, the method and corresponding software was used to compare different cross schemes and selection strategies.

• Asian-Australasian Journal of Animal Sciences
• /
• v.33 no.12
• /
• pp.1965-1974
• /
• 2020

Objective: This study consisted of two stages; the first was to determine the effect of extrusion and sieving treatments on the chemical properties of palm kernel cake (PKC), and accordingly, a follow-up experiment (second stage) was conducted to determine and compare the apparent metabolizable energy (AME), and protein and amino acid digestibility of extruded and sieved PKC. Methods: Two physical treatments, namely extrusion (using temperature profiles of 90℃/100℃/100℃, 90℃/100℃/110℃, and 90℃/100℃/120℃) and sieving (to 8 particles sizes ranging from >8.00 to 0.15 mm) were carried out to determine their effects on chemical properties, primarily crude protein (CP) and fiber contents of PKC. Based on the results from the above study, PKC that extruded with temperature profile 90/100/110℃ and of sieved size between 1.5 to 0.15 mm (which made up of near 60% of total samples) were used to determine treatments effect on AME and CP and amino acid digestibility. The second stage experiment was conducted using 64 male Cobb 500 chickens randomly assigned to 16 cages (4 cages [or replicates] per treatment) to the following four dietary groups: i) basal (control) diet, ii) basal diet containing 20% untreated PKC, iii) basal diet containing 20% extruded PKC (EPKC), and iv) basal diet containing 20% sieved PKC (SPKC). Results: Extrusion and sieving had no effect on CP and ash contents of PKC, however, both treatments reduced (p<0.05) crude fiber by 21% and 19%, respectively. Overall, extrusion and sieving reduced content of most of the amino acids except for aspartate, glutamate, alanine and lysine which increased, while serine, cysteine and tryptophan remained unchanged. Extrusion resulted in 6% increase (p<0.05) in AME and enhanced CP digestibility (p<0.05) by 32%, as compared to the untreated PKC while sieving had no effect on AME but improved CP digestibility by 39% which was not significantly different from that by extrusion. Conclusion: Extrusion is more effective than sieving and serves as a practical method to enhance AME and digestibility of CP and several amino acids in broiler chickens.

• The korean journal of orthodontics
• /
• v.26 no.5 s.58
• /
• pp.547-556
• /
• 1996

The purpose of this study was to evaluate the skeletal, dental and soft tissue profile changes following the face mask therapy in growing skeletal class III malocclusion patients. The fifteen patients with the good results were selected among the patients who visited the Department of Orthodontics in Seoul National University Hospital. The mean age was 10.63(range 7.25-13.25) years and the mean treatment duration was 9.84(range 2.00-27.00) months. Lateral cephalograms were taken just before and after face mask application. After tracing the cephalograms, thirty five items(twety angular and fifteen linear) were measured. The differences before and after the face mask therapy were compared statistically by the paired t-test(p<0.05). The results were as follows : SNA and Co-A(effective maxillary length) increased significantly after using the face mask(p<0.001), which reflects the orthopedic changes of maxilla. SNB and Co-Gn(effective mandibular length) also showed an increase(p<0.01), which may be a result of the strong growth trends of the samples. FMA, SN-GoGn and Y-axis angle increased significantly(p<0.01), which means the backward and downward rotation of the mandible. This positional change seemed to have compensated an increase of effective mandibular length. There was no statistically significant difference in angulation of upper and lower incisors between pre-treatment and post-treatment(p>0.05). In soft tissue profile, the upper lip was positioned anteriorly(p<0.01) after treatment and approximated to the normal standards.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.311-311
• /
• 2014

III-N계 물질로 이루어진 GaN 기반의 광 반도체는 직접 천이형 넓은 밴드갭 구조를 갖고 있기 때문에 적외선부터 가시광선 및 자외선까지를 포함한 폭 넓은 발광파장 조절이 가능하여 조명 및 디스플레이 관련 차세대 광원으로 많은 관심을 받고 있다. 하지만, GaN기반의 발광 다이오드는 많은 연구기관들의 오랜 연구에도 불구하고 고출력을 내는데 있어 여전히 많은 문제들이 존재한다. 그 중, 주입전류 증가에 따른 효율감소 현상은 출력을 저해하는 대표적인 요소로 알려져 있는데, 이전의 연구 결과에서 알려진 효율감소 현상의 원인으로 결정결함에 의한 누설전류, Auger 재결합, 이송자 넘침 현상 그리고 p-n접합부의 온도 상승 등의 현상이 알려져 있다 [1-2]. 하지만 여전히 주입 전류 증가에 따른 효율 감소 현상의 원인에 대해 명확한 해답은 없으며 아직도 많은 논의가 이루어 지고 있다. 따라서, 본 연구에서는 GaN기반의 청색 및 녹색 LD와 LED소자를 이용하여 주입전류 밀도의 변화에 따른 자발 발광 영역에서의 효율감소 현상의 원인을 규명하고 한다. 유기금속화학증착법(MOCVD)를 이용하여 c면 사파이어 위에 서로 다른 발광파장을 가지는 InGaN/GaN 다중양자우물구조의 질화물계 LED와 LD 박막을 제작하였으며 성장 구조에 의한 특성으로 인해 발생하는 효율 저하 현상을 방지하고자 InGaN/GaN으로 이루어진 다중양자우물층의 조성만 제어하여 청색과 녹색으로 발광하도록 하였다. 청색 및 녹색 LD 웨이퍼들을 이용하여 주입전류 증가에 따른 발광특성을 조사하기 위해 LD와 LED는 표준 팹 공정에 의해 제작되었다. 전계 발광 측정을 위해 상온에서 직류 전류를 주입하여 GaN계 청색 및 녹색 LED와 LD에 각 5 mA/cm2에서 50 mA/cm2까지 전류밀도를 증가시킴에 따라 LD 및 LED칩 형태에 상관없이 청색 LD와 LED의 파장은 약 465nm에서 약 458nm로 감소하였고 녹색 LD와 LED의 파장은 약 521nm에서 약 511~513 nm까지 단파장화가 발생했다. 이는 동일한 웨이퍼에 동일한 전류 밀도를 주입하였기 때문에 발생하는 것으로 판단된다. 그러나, 청색 LED의 효율은 50 mA/cm2에서 약 70%정도로 감소하고 반면 녹색 LED의 경우 동일한 전류밀도 하에 약 52%정도로 감소하였지만, 청색과 녹색 LD의 경우 동일한 전류 밀도의 범위 내에서 더욱 낮은 효율저하 현상을 나타내었다. 또한, 접합 온도를 측정한 바 청색소자가 녹색 소자에 비하여 낮은 접합 온도를 나타낼 뿐아니라, 청색 및 녹색 LD의 경우 LED 보다 낮은 접합 온도를 나타내고 있었다. 이는 InGaN 활성층의 In 조성이 증가할수록 비발광 센터에 의한 접합온도 상승 뿐 아니라, LD ridge 구조에서 더 많은 열이 방출되어 접합 온도가 감소될 수 있는 것으로 판단된다. 우리는 동일한 웨이퍼에 LED와 LD를 제작하였고, 동일한 전류 주입밀도를 인가하였기 때문에 LD와 LED의 효율 감소 현상의 차이는 이송자 넘침 현상, 결정 결함, 오제 재결합 등이 원인보다 활성층의 접합 온도 상승이 가장 큰 영향이 될 수 있을 것으로 판단된다.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.39 no.3
• /
• pp.285-294
• /
• 1994

Dried top and root extracts of seven different weed species, fresh top and root extracts, and various concentrations of extract (0, 5, 10 and 15%, W/V) and residue rate (0.0, 0.25. 0.5, 0.75 and 1.0%) of velvetleaf (Abutilon theophrasti Medic.) were used to study their allelopathic effects on alfalfa in the laboratory and greenhouse. Top and root aqueous extracts of common lambsquarter (Chenopodium album L.), giant foxtail (Setaria faberii Herrm), redroot pig-weed (Amaranthus retroflexus L), velvetleaf, large crabgrass (Digitaria sanguinalis L), canada thistle (Cirsium arvense L.) and prostrate knotweed (Polygonium aviculare L.) significantly inhibited germination, seedling length, weight, and vigor in alfalfa. Top growth extracts of weeds exhibited greater allelopathic effects than root extracts. Alfalfa test species, WL-320, responded significantly different to the various weed species extracts in terms of allelopathic effect. The regression slopes of various top extracts showed significant variation with respect to germination percentage. Velvetleaf (b=3.69) extracts were the most inhibitory, while large crabgrass (b=2.39) extracts had the least allelopathic effect on alfalfa. When compared the activity of fresh velvetleaf extract to that of dry velvetleaf extract, dry extract was more inhibitory to alfalfa germination and seedling growth. Germination, seedling length and weight of alfalfa were inversely proportional to the concentration of dried velvetleaf extracts. Seedling emergence and survival percentage was inhibited by velvetleaf residue mixture treatment. Also, more of the toxic effects were observed from the dried top extracts, as compared to extracts from fresh top and root. These results demonstrate the allelopathic activity of different weed species extracts and suggest that weeds may affect crop growth and development due to the inhibitory effects of allelochemicals present in weed tissue.

• Journal of Korean Foot and Ankle Society
• /
• v.20 no.3
• /
• pp.126-130
• /
• 2016

Purpose: The aim of this study was to evaluate the result of extraarticular dorsal closing wedge osteotomy in Freiberg's disease. Materials and Methods: Between February 2012 and July 2014, total 10 patients who underwent dorsal closing wedge osteotomy and followed up more than 1 year were selected for inclusion. Average age was 16.3 years, and average follow-up period was 15.5 months. The diagnosis was made using magnetic resonance imaging of those with a limitation in walking or usual activity due to pain in the metatarsal head. During operation, we removed loose body, and synovectomy was done. Osteotomy at the metatarsal neck and fixation with Kirschner wire were performed. X-ray was taken to check shortening of 2nd metatarsal and bone union. Moreover, we checked the active range of motion of 2nd metatarsophalangeal joint before and after surgery. At the last follow-up, the shortening of metatarsal, American Orthopaedic Foot and Ankle Society (AOFAS) score, visual analogue scale (VAS), and patient's subjective satisfaction were evaluated. Results: According to the Smillie's stage, there were 3 cases of stage II, 4 cases of stage III, and 3 cases of stage IV. Average bone union time on the osteotomy site was 8 weeks. Average shortening of metatarsal was 2.53 mm. Average AOFAS score improved significantly from 56.9 to 82.8 points at final follow-up (p<0.05), and average VAS score also improved significantly from 6.4 to 1.4 points at final follow-up (p<0.05). Average active range of motion at metatarsophalangeal joint improved from $28.0^{\circ}$ preoperatively to $46.5^{\circ}$ at the final follow-up. Other complications, such as metatarsalgia and arthritis, were not found; however, there was 1 case of delayed union with no symptom. Conclusion: In Freiberg's disease, dorsal closing wedge osteotomy is recommended for the improvement of clinical symptoms and range of motion.

• Journal of Chest Surgery
• /
• v.48 no.3
• /
• pp.164-173
• /
• 2015

Background: Hypertrophied myocardium is especially vulnerable to ischemic injury. This study aimed to compare the early and late clinical outcomes of three different methods of myocardial protection in patients with aortic stenosis. Methods: This retrospective study included 225 consecutive patients (mean age, 65{\pm}10 years; 123 males) with severe aortic stenosis who underwent aortic valve replacement. Patients were excluded if they had coronary artery disease, an ejection fraction <50%, more than mild aortic regurgitation, or endocarditis. The patients were divided into three groups: group A, which was treated with antegrade and retrograde cold blood cardioplegia; group B, which was treated with antegrade crystalloid cardioplegia using histidine-tryptophan-ketoglutarate (HTK) solution; and group C, treated with retrograde cold blood cardioplegia. Results: Group A contained 70 patients (31.1%), group B contained 74 patients (32.9%), and group C contained 81 patients (36%). The three groups showed significant differences with regard to the proportion of patients with a New York Heart Association functional classification ${\geq}III$ (p=0.035), N-terminal pro-brain natriuretic peptide levels (p=0.042), ejection fraction (p=0.035), left ventricular dimensions (p<0.001), left ventricular mass index (p<0.001), and right ventricular systolic pressure (p <0.001). Differences in cardiopulmonary bypass time (p=0.532) and aortic cross-clamp time (p=0.48) among the three groups were not statistically significant. During postoperative recovery, no significant differences were found regarding the use of inotropes (p=0.328), mechanical support (n=0), arrhythmias (atrial fibrillation, p=0.347; non-sustained ventricular tachycardia, p=0.1), and ventilator support time (p=0.162). No operative mortality occurred. Similarly, no significant differences were found in long-term outcomes. Conclusion: Although the three groups showed some significant differences with regard to patient characteristics, both antegrade crystalloid cardioplegia with HTK solution and retrograde cold blood cardioplegia led to early and late clinical results similar to those achieved with combined antegrade and retrograde cold blood cardioplegia.

• Food Science of Animal Resources
• /
• v.25 no.2
• /
• pp.218-225
• /
• 2005

This study was performed to determine sequence variation and RFLP of the mt DNA D-loop region using Southern blot hybridization analysis and to develop mt DNA marker affecting milk production traits in Hanwoo cows. The PCR was used to amplify an 1142 bp fragment within the D-loop region of mt DNA using specific primers. Mt DNA were digested with seven restriction enzymes and hybridized using DIG-labeled D-loop probe. The mt DNA RFLP polymorphisms were observed in the four enzymes, BamHI, RsaI, XbaI and HpaII. Nucleotide substitutions were detected at positions 441 (G/C), 469 (T/C), 503 (C/T), 569 (G/A), 614 (C/A) and 644 (C/T) of the mt DNA D-loop region between two selected lines. Significant relationship between the XbaI RFLP type and breeding value was found(p<0.05). Cows with A type had higher estimated breeding values than those with B type (P<0.05) between high and low milk production lines. Therefore, the RFLP marker of mt DNA could be used as a selection assisted tool for individuals with high milk producing ability in Hanwoo.

• Korean Journal of Remote Sensing
• /
• v.34 no.2_2
• /
• pp.351-375
• /
• 2018

This paper aims to i) introduce the characteristics of HF ocean radar and the major results and information produced by the radar networks in the Korean coasts to the readers, ii) make an up-to-date inventory of the existing radar systems, and iii) share the information related to the radar operating skill and the ocean current data application. The number of ocean radars has been showing a significant growth over the past 20 years, currently deploying more than 44 radars in the Korean coasts. Most of radars are in operation at the present time for the purposes related to the marine safety, tidal current forecast and understanding of ocean current dynamics, mainly depending on the mission of each organization operating radar network. We hope this overview paper may help expand the applicability of the ocean radar to fisheries, leisure activity on the sea, ocean resource management, oil spill response, coastal environment restoration, search and rescue, and vessel detection etc., beyond the level of understanding of tidal and ocean current dynamics. Additionally we hope this paper contributes further to the surveillance activity on our ocean territory by founding a national ocean radar network frame and to the domestic development of ocean radar system including signal processing technology.

• Journal of Chest Surgery
• /
• v.33 no.8
• /
• pp.662-668
• /
• 2000

Background: Many recent results of clinical trials show that pre-operative concurrent chemoradiotherapy and surgical resection could increase the survival of N2 positive stage IIIA non-small cell lung cancer. This study was performed to assess the feasibility, toxicity, and affect rates of concurrent chemoradiotherapy and surgical resection in N2 positive stage IIIA non-small cell lung cancer. Material and Method: Thirty-one patients who underwent preoperative concurrent chemoradiotherapy for N2 positive stage IIIA non-small-cell lung cancer from May 1997 to April 1999 were entered into the study. Mean age was 61 yrs(43∼70 yrs), There were 24 men and 7 women. The confirmation of N2 disease were achieved through mediastinoscopic biopsy(24) and CT scans(7). Induction was achieved by two cycles of cisplatin and etoposide(EP) plus concurrent chest radiotherapy to 45 Gy. Resections were done at 3 weeks after the complection of preoperative concurrent chemoradiotherapy. Resections were performed in 23 patients, excluding 5 refusals and 3 distant metastasis. Result: All patients were compled the thoracic radiotherapy except one who had distant metastasis. Twenty three patients were completed the planned 2 cycles of EP chemotherapy, and 8 patients were received only 1 cycle for severe side effects(6), refusal(1), and distant metastasis(1). There was one postoperative mortality, and the cause of death was ARDS. Three patients who had neutropenic fever and one patient who had radiation pneumonitis were required admission and treatment. Esophagitis was the most common acute side effect, but relatively well-tolerated in most patients. The complection rate of concurrent chemoradiotherapy was 74%, resection rate was 71%, pathologic complete remission rate was 13.6%, and pathologic down-staging rate was 68%. Conclusion: Morbidity related to each treatment was acceptable and many of the patients have benefited down staging of its disease. Further prospective, preferably randomized, clinical trials of larger scale may be warranted to confirm the actual benefit of preoperative concurrent chemoradiotherapy and surgical resection in N2-positive stage IIIA non-small cell lung cancer.