• Animal Bioscience
• /
• v.35 no.6
• /
• pp.826-837
• /
• 2022

Objective: Cambodia is located within the distribution range of the red junglefowl, the common ancestor of domestic chickens. Although a variety of indigenous chickens have been reared in Cambodia since ancient times, their genetic characteristics have yet to be sufficiently defined. Here, we conducted a large-scale population genetic study to investigate the genetic diversity and population genetic structure of Cambodian indigenous chickens and their phylogenetic relationships with other chicken breeds and native chickens worldwide. Methods: A Bayesian phylogenetic tree was constructed based on 625 mitochondrial DNA D-loop sequences, and Bayesian clustering analysis was performed for 666 individuals with 23 microsatellite markers, using samples collected from 28 indigenous chicken populations in 24 provinces and three commercial chicken breeds. Results: A total of 92 haplotypes of mitochondrial D-loop sequences belonging to haplogroups A to F and J were detected in Cambodian chickens; in the indigenous chickens, haplogroup D (44.4%) was the most common, and haplogroups A (21.0%) and B (13.2%) were also dominant. However, haplogroup J, which is rare in domestic chickens but abundant in Thai red junglefowl, was found at a high frequency (14.5%), whereas the frequency of haplogroup E was considerably lower (4.6%). Population genetic structure analysis based on microsatellite markers revealed the presence of three major genetic clusters in Cambodian indigenous chickens. Their genetic diversity was relatively high, which was similar to findings reported for indigenous chickens from other Southeast Asian countries. Conclusion: Cambodian indigenous chickens are characterized by mitochondrial D-loop haplotypes that are common to indigenous chickens throughout Southeast Asia, and may retain many of the haplotypes that originated from wild ancestral populations. These chickens exhibit high population genetic diversity, and the geographical distribution of three major clusters may be attributed to inter-regional trade and poultry transportation routes within Cambodia or international movement between Cambodia and other countries.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.5
• /
• pp.671-676
• /
• 2008

Forty-eight Naemi lambs (avg. BW 31.7 kg) were transported by truck for a distance of 1,450 km from Al-Jouf to Riyadh, Saudi Arabia. On arrival day, the lambs were randomly allocated to four groups receiving diets supplemented with 0.0, 0.3, 0.6 and 0.9 ppm organic chromium (Cr). Each group consisted of four separately housed replicates of three lambs each. The animals were fed ad libitum on a grower diet for 84 days. Blood samples were obtained shortly before transportation, upon arrival and at weekly intervals thereafter from all lambs for analysis of plasma and serum. Plasma glucose and serum cortisol, total protein, albumin, urea-N and total cholesterol concentrations were determined. A cursory clinical examination of the lambs, along with rectal temperature, was undertaken at different intervals during the experiment. The lambs were inoculated each with 2 ml i.v. chicken red blood cells (CRBC) on days 0, 21, and 42. Serum total, IgG and IgM antibody titers were determined at weekly intervals post-immunization. An in vivo intradermal hypersensitivity test was carried out on 6 lambs from each group on days 10 and 70. Transportation of the lambs resulted in a significant (p<0.001) elevation of serum cortisol, total protein and albumin levels, as well as increased plasma glucose concentration, with corresponding decrease in total cholesterol, while blood urea-N remained largely unchanged. These constituents returned to normal levels during subsequent weeks, with no significant differences in their concentrations being observed between the Cr-supplemented groups and controls. Rise in rectal temperature after transportation was reduced to a greater extent (p<0.05) in Cr-supplemented versus control lambs. Total, IgG and IgM antibody titers against CRBC rose significantly (p<0.05) during immunizations in all groups, with significantly and linearly higher (p<0.05) total and IgG titers in Cr-supplemented versus control lambs. By contrast, no significant effect due to Cr supplementation was recorded in IgG titers, which increased equally in Cr-fed and control groups. Skin thickness in response to intradermal inoculation of phytohaemagglutinin (PHA) was also significantly (p<0.01) increased as a result of Cr supplementation. These results indicate that dietary Cr supplementation might be useful during stress especially for enhancing immune responses in transport-stressed lambs.

• Journal of Animal Science and Technology
• /
• v.62 no.5
• /
• pp.595-604
• /
• 2020

This study investigated the effects of dietary rumen-protected L-tryptophan (TRP) supplementation (43.4 mg of L-tryptophan kg^-1 body weigt [BW]) for 65 days in Hanwoo steers on muscle development related to gene expressions and adipose tissue catabolism and fatty acid transportation in longissimus dorsi muscles. Eight Hanwoo steers (initial BW = 424.6 kg [SD 42.3]; 477 days old [SD 4.8]) were randomly allocated to two groups (n = 4) of control and treatment and were supplied with total mixed ration (TMR). The treatment group was fed with 15 g of rumen-protected TRP (0.1% of TMR as-fed basis equal to 43.4 mg of TRP kg^-1 BW) once a day at 0800 h as top-dressed to TMR. Blood samples were collected 3 times, at 0, 5, and 10 weeks of the experiment, for assessment of hematological and biochemical parameters. For gene study, the longissimus dorsi muscle samples (12 to 13 ribs, approximately 2 g) were collected from each individual by biopsy at end of the study (10 weeks). Growth performance parameters including final BW, average daily gain, and gain to feed ratio, were not different (p > 0.05) between the two groups. Hematological parameters including granulocyte, lymphocyte, monocyte, platelet, red blood cell, hematocrit, and white blood cell showed no difference (p > 0.05) between the two groups except for hemoglobin (p = 0.025), which was higher in the treatment than in the control group. Serum biochemical parameters including total protein, albumin, globulin, blood urea nitrogen, creatinine phosphokinase, glucose, nonesterified fatty acids, and triglyceride also showed no differences between the two groups (p > 0.05). Gene expression related to muscle development (Myogenic factor 6 [MYF6], myogenine [MyoG]), adipose tissue catabolism (lipoprotein lipase [LPL]), and fatty acid transformation indicator (fatty acid binding protein 4 [FABP4]) were increased in the treatment group compared to the control group (p < 0.05). Collectively, supplementation of TRP (65 days in this study) promotes muscle development and increases the ability of the animals to catabolize and transport fat in muscles due to an increase in expressions of MYF6, MyoG, FABP4, and LPL gene.

• Journal of Korean Society of Transportation
• /
• v.33 no.2
• /
• pp.170-181
• /
• 2015

This study explores passengers' travel characteristics at six bus stops on the Seoul Ring Expressway using smart traffic card data. Based on the characteristics, political strategies to improve bus facilities on expressway are suggested. Firstly, among them two bus stops of Guri and Uiwang-Cheonggye have higher transfer rate of passengers, 37.56% and 36.9% of the total intercity (red) bus passengers on the expressway, respectively. Secondly, Uiwang-Cheonggye bus stop has the highest transfer rate, and Guri bus stop has also higher transfer rate and the highest on-and-off passengers. It implies that both bus stops need to be prioritized for improving bus stop facility, access roads, and connection facility between the bi-directional stops. Thirdly, Guri (down) bus stop has relatively longer waiting time for transfer, thus shorter bus headways running the bus stop should be considered. Lastly, most passengers using both stops come to and from Bundang-gu in Geongnam City. Overall, the results of this study would be helpful for transport planners to develop effective bus route policies and bus operation.

• Journal of Korean Society of Transportation
• /
• v.21 no.5
• /
• pp.41-48
• /
• 2003

Korea Claim Adjustor Association(KCAA) defines the near pedestrian crossing accidents as those accidents that occurred in the area within 25m from pedestrian crossing on the arterial road and within 15m from pedestrian crossing on other classes of road. Accidents between pedestrian crossing and stop line are classified as the accident near pedestrian crossing. Reviewing of current statute and court precedent, three kinds of traffic accidents which are accidents occurred in the pedestrian crossing. near pedestrian crossing and the area between pedestrian crossing and stop line. should be distinguished by different pedestrian contributory negligence. To find out how different they are. we surveyed transportation society members about the contributory negligence of traffic accidents between pedestrian crossing and stop line and the results are as follows : (1) The current two classification of pedestrian crossing accidents and near pedestrian crossing accidents should be changed to three classification of pedestrian crossing accidents that includes accidents on pedestrian crossing, near pedestrian crossing and between pedestrian crossing and the stop line. (2) For the pedestrian's contributory negligence, the least reasonability to pedestrian is accident on the pedestrian crossing. The next one is the accident between pedestrian crossing and stop line and the last is the accident near pedestrian crossing. (3) Pedestrian contributory negligence for accident by space is recommended as 〈table 8〉, 〈table 9〉, 〈table 10〉. (4) Contributory negligence rate of the accident on the pedestrian crossing during red light should be modified to be less than that of near pedestrian crossing.

• Journal of Korean Society of Transportation
• /
• v.22 no.7 s.78
• /
• pp.41-48
• /
• 2004

We may consider the inducement of demand to public transportation as a solution to relieve traffic congestion and pollution. Subway has merits as moving on schedule, transporting more people than bus. But subway is required a vast investment in the early stage of construction has a huge debt. So it runs into red figures, and on this account, services of subway are falling more and more. Development of subway's operation cost function is useful to understand structure of subway's operation and catch the relations of operation cost and actual results. In addition, we can present the policy that is a helpful to the operation as development of operation cost function. But there are short of studies about operation cost deal with a subway comparison with local train. Because local train has many lines and data, on the other hand, subway has one to four lines and less data. Most of previous studies sought the operation cost function of Seoul. So this study aimed to develop and apply the operation cost function of Seoul, Incheon, Busan and Daegu area using full allocation method. In this study, we considered the number of passengers, track-km, train-km, revenue as actual results. By appling the operation cost function, we compared the average cost of each city and confirmed the existence of economies of scale about the number of passengers, train-km.

• Journal of Korean Society of Transportation
• /
• v.26 no.4
• /
• pp.51-61
• /
• 2008

Most of Korea's 15 local airports, with the exception Jeju, Gimpo and Gimhae airports, have been several billion Won in the red each year. It has been reported that one of the causes of the poor financial performance is inaccurate air traffic demand predictions. Under the situation, the entry of low-cost carrier air service using turbo-prop airplanes into the domestic airlines market gets a wide range of support, which is expected to promote the convenience of consumers and help to activate local airports. In this study, the authors (1) suggest a high-speed transport demand model among existing airlines, Korea Train Express (KTX) and low-cost carrier air service; (2) try to make low-cost air carrier demand predictions for a route between Seoul and Daegu through a stated-preference survey; and (3), examine possible effectiveness of selected policy measures by establishing an estimation model. First, fare has a strong influence for mode choice between high-speed transport modes when considering the entry of low-cost carrier air service between Seoul and Daegu. Even low-cost carrier air service fare is set at 38,000 won, which is considerably low compared with that of KTX, in the regions where the total travel time is the same for both low-cost carrier air service and KTX, the probability of selecting low-cost carrier air service is 0.1, which shows little possibility of modal change between high speed transportation means. It is suggested that the fare of low-cost air service between Seoul and Daegu should be within the range of from of 38,000 to 44,000 Won; if it is higher, the demand is likely to be lower than expected.

• The Journal of The Korea Institute of Intelligent Transport Systems
• /
• v.10 no.1
• /
• pp.1-15
• /
• 2011

The RLC systems is one of the intelligent transportation systems that has gained a nation-wide support for last decades and being installed to discourage motorists from running the red lights at signalized intersections. It is taken for granted that the RLC will provide motorists with increased safety, so that their installments are always justifiable. However, in order to acquire more efficiency and wider supports from the general public in future RLC installments, an improved methodology for analyzing the effects of the RLC systems is required. In order to satisfy this requirement, this research performed the following tasks. First, the number of signal violations after the RLC systems were investigated in order to check its resulting effects. Second, the number of crashes after the RLC systems were collected and compared with the number of signal violations. Third, a statistical analysis was carried out to develop the relationships between the signal violations and the crashes based on negative binomial distribution. The analysis revealed that the number of crashes has a close relationship with the RLC placement, traffic volume, vehicle speed, the number of phases, and the number of lanes for major approaches. Finally, based on the results found in this analysis, this research presents a methodology for analyzing the safety effects of placing the RLC that should be of service when investigating the economic consequences of the RLC systems.

• Journal of the Society of Naval Architects of Korea
• /
• v.49 no.3
• /
• pp.264-272
• /
• 2012

A study on the IR(InfraRed) signature of a naval ship has been performed using well known IR signature analysis software, ShipIR/NTCS. Variations of the IR signature radiated from skins of a naval ship have been investigated according to the monthly averaged marine climate conditions. An unclassified destroyer model with and without applying the washdown system was applied to compare the influence on the signature under the background changes. The marine background models were created from the observed data by a buoy of Korea Meterological Administration(KMA). The sensitivity of the ship signature against the climate variables such as air temperature, sea temperature, relative humidity has been studied as well. The seasons which show extreme(max, min) skin signature change by whether the washdown is applied or not. The sensitivities of the air temperature and the sea temperature for a dry-ship reversed by applying the washdown on the ship surfaces.

• International Journal of Highway Engineering
• /
• v.19 no.2
• /
• pp.167-174
• /
• 2017

PURPOSES: This study aims to analyze the impact of the implementation of a school zone traffic safety improvement project on the number of accidents involving children in these zones. METHODS : To analyze the correlation between school zone traffic safety features of roads in the zone and the number of accidents involving children, we developed an occurrence probability model of traffic accidents involving children by using a binary logistic regression model with SPSS 23.0 software. Two separate models were developed for two zones: interior block and arterial road. RESULTS :The model depicted that in the case of the interior block, shorter sidewalk width, speed bump, and an elevated crosswalk were key factors affecting the occurrence of accidents involving children. In the case of arterial roads exceeding a width of 12 m, the speed limit, roadside barriers, and red paving of road surfaces were found to be the key factors. CONCLUSIONS:The results of this study can serve as the elementary research data to help improve the effectiveness of school zone traffic safety improvement projects and school zone road repair projects in future.