• Asian-Australasian Journal of Animal Sciences
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• v.31 no.11
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• pp.1738-1746
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• 2018

Objective: The aim of the experiment was to assess the effect of increasing amounts of Leucaena leucocephala forage on dry matter intake (DMI), organic matter intake (OMI), enteric methane production, rumen fermentation pattern and protozoa population in cattle fed Pennisetum purpureum and housed in respiration chambers. Methods: Five crossbred heifers (Bos taurus${\times}$Bos indicus) (BW: $295{\pm}6kg$) were fed chopped P. purpureum grass and increasing levels of L. leucocephala (0%, 20%, 40%, 60%, and 80% of dry matter [DM]) in a $5{\times}5$ Latin square design. Results: The voluntary intake and methane production were measured for 23 h per day in respiration chambers; molar proportions of volatile fatty acids (VFAs) were determined at 6 h postprandial period. Molar concentration of VFAs in rumen liquor were similar (p>0.05) between treatments. However, methane production decreased linearly (p<0.005), recording a maximum reduction of up to ~61% with 80% of DM incorporation of L. leucocephala in the ration and no changes (p>0.05) in rumen protozoa population were found. Conclusion: Inclusion of 80% of L. leucocephala in the diet of heifers fed low-quality tropical forages has the capacity to reduce up to 61.3% enteric methane emission without affecting DMI, OMI, and protozoa population in rumen liquor.

• Journal of the Korean Chemical Society
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• v.63 no.4
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• pp.253-259
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• 2019

5-Aminoimidazole-4-carboxamide ribonucleotide (AICAR), a structural analog of adenosine monophosphate (AMP), promotes oxidative remodeling in muscle cells. AICAR activates AMP-dependent protein kinase (AMPK), thus increasing lipid metabolism, respiration, and mitochondrial counts. This process is called oxidative remodeling, which enhances the physical endurance of mice. To test this drug on an invertebrate that is genetically similar to humans, we used the small water crustacean Daphnia magna, which is sensitive to changes in water conditions. We tested the effects of pH on the efficacy of AICAR using two methods. One method measured oxygen consumption of Daphnia in oxygen chambers. The other method determined lipid levels of Daphnia through fluorescent tagging of lipids. The results showed that when exposed to AICAR at pH 6.58, D. magna consumed more oxygen and had lower overall levels of lipids, which is consistent with the expected effects of AICAR, such as increased respiration and lipid metabolism.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.3
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• pp.307-312
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• 2000

Fasting heat production (FHP) of growing buffalo calves (Bubalus bubalis) in the body weight range of 76 to 236 kg was determined using open circuit respiration chamber. The details of the chambers, calibration of gas analysers and operation of the systems are described. Animals were fasted for 96 hrs during which only water was provided. FHP was determined during next 24 hrs. The mean oxygen consumed, carbon dioxide and methane produced and urinary N excretion per 24 h was $17.03{\ell}$, $11.70{\ell}$, and $0.12{\ell}$ and 0.35 g respectively. The mean respiratory quotient ranged from 0.68 to 0.71, which indicated that post absorptive stage is reached after 96 hrs in growing buffalo calves previously fed ammoniated straw-based ration. Mean FHP of calves was $331.4kJ/kg\;W^{0.75}$. FHP of calves with range of mean body weights of 167 to 235 kg, although nonsignificant but, was almost 12% higher than of calves having mean body weight of 101 kg. Suitable exponent to body weight to describe FHP of buffalo calves was 0.87.

• Nuclear Engineering and Technology
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• v.54 no.12
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• pp.4644-4651
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• 2022

Due to its short half-life, thoron gas has been assumed to have negligible health hazards on humans compared to radon. But, one of the decay products with a long half-life can make it to be transported to a long distance and to cause a severe internal dose through respiration. Since most commercial radon detectors can not discriminate thoron signals from radon signals, it is very common to overestimate radon doses which in turn result in biased estimation of lung cancer risk in epidemiological studies. Though some methods had been suggested to measure thoron and radon separately, they could not be used for real-time measurement because of CR-39 or LR-115. In this study, an effective method was suggested to measure radon and thoron separately from the free air. It was observed that the activity of thoron decreases exponentially due to delay time caused by a long pipe between two chambers. Therefore from two ion chambers apart in time, it was demonstrated that thoron and radon could be measured separately and simultaneously. We also developed a collimated alpha source and with this source and an SBD, we could convert the ion chamber reading to count rate in cps.

• Korean Journal of Environmental Biology
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• v.32 no.4
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• pp.389-394
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• 2014

This study was conducted to find out the soil $CO_2$ emission characteristic due to rain fall pattern and intensity changes. Using Automatic Opening and Closing Chambers (AOCCs), we have measured annual soil respiration changes in Pinus koraiensis plantation at Seoul National University experimental forest in Mt. Taehwa. In addition, we have monitored heterotrophic respiration at trenching sites ($4{\times}6m$). Based on the one year data of soil respiration and heterotrophic respiration, we observed that 24% of soil respiration was derived from root respiration. During the rainy season (end of July to September), soil respiration at trenching site and trenching with rainfall interception site were measure during portable soil respiration analyzer (GMP343, Vaisala, Helsinki, Finland). Surprisingly, even after days of continuous heavy rain, soil water content did not exceed 20%. Based on this observation, we suggest that the maximum water holding capacity is about 20%, and relatively lower soil water contents during the dry season affect the vital degree of trees and soil microbe. As for soil respiration under different rain intensity, it was increased about 14.4% under 10 mm precipitation. But the high-intensity rain condition, such as more than 10 mm precipitation, caused the decrease of soil respiration up to 25.5%. Taken together, this study suggests that the pattern of soil respiration can be regulated by not only soil temperature but also due to the rain fall intensity.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.3
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• pp.203-208
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• 2007

The woody tissue respiration rates in stems ($R_{stem}$) of red pine (Pinus densiflora Sieb. et Zucc.) forest in Higashi-Hiroshima, west Japan, were measured using an open flow measurement system with several chambers in two seasons (the winter and summer in 2002). $R_{stem}$ ranged from 0.25 to $0.55{\mu}mol\;m^{-2}s^{-1}$ in winter, and from 1.25 to $1.63{\mu}mol\;m^{-2}s^{-1}$ in summer. The variability of $R_{stem}$ among the sampled trees (n=15) was similar between the two seasons, with the coefficient variation of about 23%. The numbers of sampling points required to estimate the stem respiration rate within 10 to 20% of its actual value were 24 and 6, respectively in both seasons (probability level is 95%). Based on the relationship between stem temperature and average $R_{stem}$ the $Q_{10}$ values of the winter and summer seasons were 1.49 and 1.45, respectively. The $R_{20}$($R_{stem}$ at $20^{\circ}C$ of stem temperature) was higher in summer ($1.23{\mu}mol\;m^{-2}s^{-1}$) than winter ($0.61{\mu}mol\;m^{-2}s^{-1}$). The woody tissue respiration in stems of red pine trees during the summer season amounted about 50% of the total respiration rates.

• Journal of Animal Reproduction and Biotechnology
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• v.34 no.3
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• pp.173-182
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• 2019

This study was performed to evaluate the effect of heat stress on the status of physiological responses, blood parameter, serum T3 and cortisol, and heat shock proteins (HSP 27, 70, and 90) of Hanwoo cattle. Six Hanwoo steers (242.8 ± 7.2 kg of BW) were housed in the climate-controlled respiration chambers. The experiment consisted of 7 days (control; 0 day) at thermoneutral (air temperature (Ta) of 15℃ and relative humidity (RH) of 60%; temperature-humidity index (THI) = 64), and by 3 and 6 days (treatment groups) at heat stress (Ta of 35℃ and RH of 60%; THI = 87). Body temperature of each parts (frank, rump, perineum and foot) and rectal temperature elevated in heat stress groups (3 days and 6 days) than the control group (0 day). Respiration rates increased in 3 days and 6 days (88.5 ± 0.96 bpm and 86.3 ± 0.63 bpm, respectively) from 0 days (39.5 ± 0.65 bpm). Feed intake significantly decreased in heat stress groups (3 days and 6 days, 3.7 ± 0.14 kg and 4.0 ± 0.15 kg, respectively) than the control group (0 day, 5.0 ± 0.00 kg). In addition, final BW significantly decreased in heat stress groups (3 days and 6 days, 211.8 ± 4.75 kg and 215.5 ± 3.50 kg, respectively) than the control group (0 day, 240.0 ± 25.00 kg). However, heat stress has no significant effect on blood parameter, serum T3 and cortisol. Nevertheless, heat stress increased HSPs mRNA expression in liver tissue, and serum concentration of HSPs. Despite Hanwoo cattle may have high adaptive ability to heat stress, our results suggested that heat stress directly effect on body temperature and respiration rate as well as serum and tissue HSPs. Therefore, we are recommended that HSPs could be the most appropriate indicators of Hanwoo cattle response to heat stress.

• Journal of Aquaculture
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• v.9 no.2
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• pp.179-186
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• 1996

Zoeal stage's larvae of pandalid shrimp Pandalus hypsinotus, is distributed off the East sea and esteemed as a valuable shrimp resource in Korea, were reared in $10^{\circ}C$ temperature-controlled chambers and inverstigated the energy budget. The total energy intake per larva of zoea I to VI stages fed on Artemia nauplii was 140.88 J. The energy loss by respiration, molting, and excretion were 16.22 J, 1.19 J, and 106,40 J, respectively. The amount of energy used by growth was 17.07 J. Pandalid larvae assimilated $24.47\%$ of the ingested food. The gross efficiency ($K_1$) calculated by the equation of (growth+exuviae)/ingestion $rate{\times}100$ was $12.96\%$, and the net growth rate ($K_2$) calculated by the equation of (growth rate + exuviae)/(growth rate+ exuviae+ respiration rate)${\times}100$ was $52.96\%$. The percentage used for somatic growth and maintenance among the assimilated energy were $49.51\%$ and $47.04\%$ respectively.

• Journal of Ecology and Environment
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• v.42 no.4
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• pp.272-277
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• 2018

Background: Studying the ecosystem carbon cycle requires analysis of interrelationships between soil respiration (Rs) and the environment to evaluate the balance. Various methods and instruments have been used to measure Rs. The closed chamber method, which is currently widely used to determine Rs, creates a closed space on the soil surface, measures $CO_2$ concentration in the inner space, and calculates Rs from the increase. Accordingly, the method is divided into automatic or manual chamber methods (ACM and MCM, respectively). However, errors of these methods and differences in instruments are unclear. Therefore, we evaluated the characteristics and difference of Rs values calculated using both methods with actual data. Results: Both methods determined seasonal variation patterns of Rs, reflecting overall changes in soil temperature (Ts). ACM clearly showed detailed changes in Rs, but MCM did not, because such small changes are unknown as Rs values are collected monthly. Additionally, Rs measured using MCM was higher than that using ACM and differed depending on measured plots, but showed similar tendencies with all measurement times and plots. Contrastingly, MCM Rs values in August for plot 4 were very high compared with ACM Rs values because of soil disturbances that easily occur during MCM measurements. Comparing Rs values calculated using monthly means with those calculated using MCM, the ACM calculated values for monthly averages were higher or lower than those of similar measurement times using the MCM. The difference between the ACM and MCM was attributed to greater or lesser differences. These Rs values estimated the carbon released into the atmosphere during measurement periods to be approximately 57% higher with MCM than with ACM, at 5.1 and $7.9C\;ton\;ha^{-1}$, respectively. Conclusion: ACM calculated average values based on various Rs values as high and low for measurement periods, but the MCM produced only specific values for measurement times as representative values. Therefore, MCM may exhibit large errors in selection differences during Rs measurements. Therefore, to reduce this error using MCM, the time and frequency of measurement should be set to obtain Rs under various environmental conditions. Contrastingly, the MCM measurement is obtained during $CO_2$ evaluation in the soil owing to soil disturbance caused by measuring equipment, so close attention should be paid to measurements. This is because the measurement process is disturbed by high $CO_2$ soil concentration, and even small soil disturbances could release high levels into the chamber, causing large Rs errors. Therefore, the MCM should be adequately mastered before using the device to measure Rs.

• Korean Journal of Agricultural and Forest Meteorology
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• v.7 no.1
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• pp.107-114
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• 2005

Soil CO₂ emission is one of the primary components in carbon balance of terrestrial ecosystems. In soil CO₂ flux measurements, chamber method is currently the most common technique. Prior to compare or synthesize the data collected from different chamber methods, potential biases must be quantified for each measurement system. We have conducted an intercomparison experiment among four closed dynamic chamber systems and an automatic open-closed chamber system in a temperature-controlled phytotron. Due to the disturbed CO₂ concentrations inside the phytotron during the measurements with closed dynamic chambers and the changes in soil water content, the interpretation of the data was difficult to quantify the biases of individual methods. However, the experiment provided not only valuable information on the performance characteristics of the five instruments to varying soil temperature and CO₂ concentration but also useful insights for better designs and strategy for future intercomparison in a controlled environment.