• Title/Summary/Keyword: Short day response

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Compensatory Responses of Nile Tilapia Oreochromis niloticus under Different Feed-Deprivation Regimes

  • Gao, Yang;Lee, Jeong-Yeol
    • Fisheries and Aquatic Sciences
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    • v.15 no.4
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    • pp.305-311
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    • 2012
  • We investigated compensatory growth of Nile Tilapia Oreochromis niloticus in structural size and live weight in response to different deprivation periods and refeeding. Four treatments were assigned randomly to fish in 12 glass tanks, with each treatment performed in triplicate. The control group was fed to satiation three times a day throughout the experiment. The other three treatment groups were starved for 1 week (S1), 2 weeks (S2), or 4 weeks (S4) and then fed until the end of the experiment. After the experiment, no significant differences were observed among S1, S2, and the control group in average weight or length, whereas the weight and length of S4 were significantly reduced. Relative condition factors of the three starved groups decreased significantly until the end of the restricted period but recovered rapidly after refeeding. The specific growth rate in weight ($SGR_W$) of the three restricted groups recovered quickly upon refeeding and were significantly higher than the control group, but these differences disappeared gradually until the end of the experiment. No significant difference in specific growth rate in length ($SGR_L$) was noted between the control group and the three restricted groups after refeeding. All three groups showed hyperphagia for a short period upon refeeding, and no statistical differences were observed in feeding efficiency among the four groups.

Response of Soybean Growth to Elevated $CO_{2}$ Conditions

  • Kim Young-Guk;Lee Jae-Eun;Kim Sok-Dong;Shin Jin-Chul
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.4
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    • pp.303-309
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    • 2006
  • The study examined the effects of $CO_2$ enrichment on growth of soybean (Glycine max). Two soybean varieties were used, Taekwang and Cheongja. The plants were grown in growth chambers with a 12-h photoperiod and a day/night temperature of $28/21^{\circ}C$ at the seedling stage and $30/23^{\circ}C$ from the flowering stage. The plants were exposed to the two elevated $CO_2$ levels of 500 and 700 ppm and the ambient level of 350 ppm. Results of the experiment showed that at the second-node trifoliate stage of the two varieties, the elevated $CO_2$ increased plant height, leaf area and dry weight. The elevated $CO_2$ also raised the photosynthetic rate of soybean as compared to the ambient level. From the beginning bloom stage to the full maturity stage of the two varieties, the elevated $CO_2$ increased plant height, leaf area, seed weight and photosynthetic rate. The stomatal conductance and transpiration rate decreased on long days relative to short days of treatment. Through the entire stages, the elevated $CO_2$ increased the water use efficiency of soybean plants because stomatal conductance and transpiration rate decreased at the elevated $CO_2$ levels relative to the ambient level.

Comparative randomized study of propofol target-controlled infusion versus sevoflurane anesthesia for third molar extraction

  • Chung, Patrick K;Dhanrajani, Parmanand
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.18 no.3
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    • pp.169-175
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    • 2018
  • Background: The objective of this study was to compare hemodynamic and recovery characteristics of total intravenous anesthesia using propofol target-controlled infusion (TCI) versus sevoflurane for extraction of four third molar teeth. Methods: One hundred patients undergoing extraction of four third molar teeth under general anesthesia were randomized to one of two groups. Group 1 received propofol TCI-oxygen for induction and propofol TCI-oxygen-air for maintenance. Group II received a propofol bolus of 2 mg/kg for induction and sevoflurane-oxygen-air for maintenance. Heart rate, mean arterial pressure (MAP), operating time, time to emergence, nausea and vomiting, and sedation and pain scores were measured in each group. Results: Demographic data, including age, gender, weight, and height, were not significantly different between the two groups. The MAP was significantly higher after intubation (P = 0.007) and injection of anesthesia (P = 0.004) in the propofol group than in the sevoflurane group, with significant reflex bradycardia (P = 0.028). The mean time to emergence from anesthesia using propofol was 25 s shorter than that of sevoflurane (P = 0.02). Postoperatively, the propofol group was less sedated than the sevoflurane group at 30 min (0.02 versus 0.12), but this difference was not significant (P = 0.065). Conclusion: Both propofol TCI and sevoflurane are good alternatives for induction and maintenance of anesthesia for short day-case surgery. However, propofol TCI does not blunt the hemodynamic response to sudden, severe stimuli as strongly as sevoflurane, and this limitation may be a cause for concern in patients with cardiac comorbidities.

Dynamic Interaction between Conditional Stock Market Volatility and Macroeconomic Uncertainty of Bangladesh

  • ALI, Mostafa;CHOWDHURY, Md. Ali Arshad
    • Asian Journal of Business Environment
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    • v.11 no.4
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    • pp.17-29
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    • 2021
  • Purpose: The aim of this study is to explore the dynamic linkage between conditional stock market volatility and macroeconomic uncertainty of Bangladesh. Research design, data, and methodology: This study uses monthly data covering the time period from January 2005 to December 2018. A comprehensive set of macroeconomic variables, namely industrial production index (IP), consumer price index (CPI), broad money supply (M2), 91-day treasury bill rate (TB), treasury bond yield (GB), exchange rate (EX), inflow of foreign remittance (RT) and stock market index of DSEX are used for analysis. Symmetric and asymmetric univariate GARCH family of models and multivariate VAR model, along with block exogeneity and impulse response functions, are implemented on conditional volatility series to discover the possible interactions and causal relations between macroeconomic forces and stock return. Results: The analysis of the study exhibits time-varying volatility and volatility persistence in all the variables of interest. Moreover, the asymmetric effect is found significant in the stock return and most of the growth series of macroeconomic fundamentals. Results from the multivariate VAR model indicate that only short-term interest rate significantly influence the stock market volatility, while conditional stock return volatility is significant in explaining the volatility of industrial production, inflation, and treasury bill rate. Conclusion: The findings suggest an increasing interdependence between the money market and equity market as well as the macroeconomic fundamentals of Bangladesh.

Elevation of heart-femoral pulse wave velocity by short-term low sodium diet followed by high sodium diet in hypertensive patients with sodium sensitivity

  • Rhee, Moo-Yong;Kim, Ji-Hyun;Na, Sang-Hoon;Chung, Jin-Wook;Bae, Jun-Ho;Nah, Deuk-Young;Gu, Namyi;Kim, Hae-Young
    • Nutrition Research and Practice
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    • v.10 no.3
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    • pp.288-293
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    • 2016
  • BACKGROUND/OBJECTIVES: We compared changes in heart-femoral pulse wave velocity (hfPWV) in response to low sodium and high sodium diet between individuals with sodium sensitivity (SS) and resistance (SR) to evaluate the influence of sodium intake on arterial stiffness. SUBJECTS/METHODS: Thirty-one hypertensive and 70 normotensive individuals were given 7 days of low sodium dietary approach to stop hypertension (DASH) diet (LSD, 100 mmol NaCl/day) followed by 7 days of high sodium DASH diet (HSD, 300 mmol NaCl/day) during 2 weeks of hospitalization. The hfPWV was measured and compared after the LSD and HSD. RESULTS: The hfPWV was significantly elevated from LSD to HSD in individuals with SS (P = 0.001) independently of changes in mean arterial pressure (P = 0.037). Conversely, there was no significant elevation of hfPWV from LSD to HSD in individuals with SR. The percent change in hfPWV from the LSD to the HSD in individuals with SS was higher than that in individuals with SR. Subgroup analysis revealed that individuals with both SS and hypertension showed significant elevation of hfPWV from LSD to HSD upon adjusted analysis using changes of the means arterial pressure (P = 0.040). However, there was no significant elevation of hfPWV in individuals with SS and normotension. CONCLUSION: High sodium intake elevated hfPWV in hypertensive individuals with SS, suggesting that high sodium intake increases aortic stiffness, and may contribute to enhanced cardiovascular risk in hypertensive individuals with SS.

Aortic Remodelling in Chronic Nicotine-Administered Rat

  • Zainalabidin, Satirah;Budin, Siti Balkis;Ramalingam, Anand;Lim, Yi Cheng
    • The Korean Journal of Physiology and Pharmacology
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    • v.18 no.5
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    • pp.411-418
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    • 2014
  • Vascular remodelling is an adaptive mechanism, which counteracts pressure changes in blood circulation. Nicotine content in cigarette increases the risk of hypertension. The exact relationship between nicotine and vascular remodelling still remain unknown. Current study was aimed to determine the effect of clinically relevant dosage of nicotine (equivalent to light smoker) on aortic reactivity, oxidative stress markers and histomorphological changes. Twelve age-matched male Sprague-Dawley rats were randomly divided into two groups, i.e.: normal saline as control or 0.6 mg/kg nicotine for 28 days (i.p., n=6 per group). On day-29, the rats were sacrificed and the thoracic aorta was dissected immediately for further studies. Mean arterial pressure (MAP) and pulse pressure (PP) of nicotine-treated vs. control were significantly increased (p<0.05). Nicotine-treated group showed significant (p<0.05) increase tunica media thickness, and decrease in lumen diameter, suggesting vascular remodelling which lead to prior hypertension state. The phenylephrine (PE)-induced contractile response in nicotine group was significantly higher than control group ($ED_{50}=1.44{\times}10^5M$ vs. $4.9{\times}10^6M$) (p<0.05~0.001). However, nicotine-treated rat showed significantly lower endothelium-dependent relaxation response to acetylcholine (ACh) than in control group ($ED_{50}=6.17{\times}10^7M$ vs. $2.82{\times}10^7M$) (p<0.05), indicating loss of primary vascular function. Malondialdehyde (MDA), a lipid peroxidation marker was significantly higher in nicotine group. Superoxide dismutase (SOD) enzymatic activity and glutathione (GSH) were all reduced in nicotine group (p<0.05) vs. control, suggesting nicotine induces oxidative imbalance. In short, chronic nicotine administration impaired aortic reactivity, probably via redox imbalance and vascular remodelling mechanism.

The Iliac Fossa Transplant as an Acute Rejection Model in Porcine Kidney Transplantation: a Tool for the Safety Study of the Stem Cell- induced Humanized Tissue (돼지 장기이식에서 급성거부반응 연구에 효과적인 엉덩오목이식 동물모델: 줄기세포유래 Humanized 조직의 안전성 평가모델)

  • Kwak, Ho-Hyun;Nam, Hyun-Suk;Woo, Heung-Myong
    • Journal of Veterinary Clinics
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    • v.28 no.1
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    • pp.63-70
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    • 2011
  • To consider the iliac fossa as the vascular anastomosis site of kidney transplantation for the short-term study of acute rejection in pigs. Twelve domestic pigs weighing 39~48 kg underwent heterotopic renal allgraft transplantation. The experimental animals were divided into 2 groups in terms of renal vascular anastomosis site; the external iliac artery and vein were used in iliac fossa model (n = 6), the abdominal aorta and the caudal vena cava inferior to the kidney were used in abdominal cavity model (n = 6). Renal function was evaluated by daily measurement of plasma creatinine and BUN concentrations. The experiments' health including postoperative complications was also assessed daily for 8 days after transplantation. After euthanazation gross and histopathologic analysis was performed. All six pigs in iliac fossa model developed neuropraxia and lameness of the ipsilateral pelvic limb. However, no necrosis was observed in any pigs. In the abdominal cavity model, durations of both the surgical operation and the vascular anastomosis were significantly longer than those in the iliac fossa model. Furthermore, ischemia injury of the transplanted kidney was increased in abdominal cavity model, which induced accelerated-acute immune response from day 4 after transplantation. Despite of pelvic limb complication, the iliac fossa model showed more advantages including not only less ischemia time related to easy vascular anastomosis, but also less immune response during the acute rejection period. The results indicate that the iliac fossa model may be appropriate to the study of acute rejection in porcine kidney transplantation.

A New Poinsettia 'Red Stone' with Excellent Branching Ability (분지력이 우수한 적색 포인세티아 'Red Stone' 육성)

  • Lee, Eun-Kyung;Kim, Won-Hee;Kim, Seung-Tae;Lee, Kwang-Seek;Lee, Su-Young
    • Korean Journal of Breeding Science
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    • v.43 no.6
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    • pp.591-594
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    • 2011
  • A new poinsettia(Euphorbia pulcherrima. Willd. ex Klotzch) cultivar 'Red Stone' was bred by the National Institute of Horticultural and Herbal Science (NIHHS) in 2009. In 2006, a cross was made between 'Freedom Rose', a cultivar with vigorous growth and deep pink bracts, and 'Enduring Pink', a cultivar with pink bracts early colored. 'Red Stone' was finally selected in 2009 after the investigation of the growth and flowering characteristics from 2007 to 2009. 'Red Stone' has red elliptic bracts and strong rugosities between bract veins. Leaf blade is ovate and very dark green. Stem color is reddish and petiole length is medium but relatively longer than that of 'Pepride Red', control cultivar. 'Red Stone' develops as many as 3.8 branches and which is more than double of 'Pepride Red'. Its bracts and transitional leaves are fully colored at 7.5 weeks after short-day commencement. Plant variety protection right of 'Red Stone' was registered in April 2011, and its grant number is 3487.

Effects of Short-term Acute Heat Stress on Physiological Responses and Heat Shock Proteins of Hanwoo Steer (Korean Cattle)

  • Baek, Youl-Chang;Kim, Minseok;Jeong, Jin-Young;Oh, Young-Kyoon;Lee, Sung-Dae;Lee, Yoo-Kyung;Ji, Sang-Yun;Choi, Hyuck
    • 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.

Altitude training as a powerful corrective intervention in correctin insulin resistance

  • Chen, Shu-Man;Kuo, Chia-Hua
    • Korean Journal of Exercise Nutrition
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    • v.16 no.2
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    • pp.65-71
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    • 2012
  • Oxygen is the final acceptor of electron transport from fat and carbohydrate oxidation, which is the rate-limiting factor for cellular ATP production. Under altitude hypoxia condition, energy reliance on anaerobic glycolysis increases to compensate for the shortfall caused by reduced fatty acid oxidation [1]. Therefore, training at altitude is expected to strongly influence the human metabolic system, and has the potential to be designed as a non-pharmacological or recreational intervention regimen for correcting diabetes or related metabolic problems. However, most people cannot accommodate high altitude exposure above 4500 M due to acute mountain sickness (AMS) and insulin resistance corresponding to a increased levels of the stress hormones cortisol and catecholamine [2]. Thus, less stringent conditions were evaluated to determine whether glucose tolerance and insulin sensitivity could be improved by moderate altitude exposure (below 4000 M). In 2003, we and another group in Austria reported that short-term moderate altitude exposure plus endurance-related physical activity significantly improves glucose tolerance (not fasting glucose) in humans [3,4], which is associated with the improvement in the whole-body insulin sensitivity [5]. With daily hiking at an altitude of approximately 4000 M, glucose tolerance can still be improved but fasting glucose was slightly elevated. Individuals vary widely in their response to altitude challenge. In particular, the improvement in glucose tolerance and insulin sensitivity by prolonged altitude hiking activity is not apparent in those individuals with low baseline DHEA-S concentration [6]. In addition, hematopoietic adaptation against altitude hypoxia can also be impaired in individuals with low DHEA-S. In short-lived mammals like rodents, the DHEA-S level is barely detectable since their adrenal cortex does not appear to produce this steroid [7]. In this model, exercise training recovery under prolonged hypoxia exposure (14-15% oxygen, 8 h per day for 6 weeks) can still improve insulin sensitivity, secondary to an effective suppression of adiposity [8]. Genetically obese rats exhibit hyperinsulinemia (sign of insulin resistance) with up-regulated baseline levels of AMP-activated protein kinase and AS160 phosphorylation in skeletal muscle compared to lean rats. After prolonged hypoxia training, this abnormality can be reversed concomitant with an approximately 50% increase in GLUT4 protein expression. Additionally, prolonged moderate hypoxia training results in decreased diffusion distance of muscle fiber (reduced cross-sectional area) without affecting muscle weight. In humans, moderate hypoxia increases postprandial blood distribution towards skeletal muscle during a training recovery. This physiological response plays a role in the redistribution of fuel storage among important energy storage sites and may explain its potent effect on changing body composition. Conclusion: Prolonged moderate altitude hypoxia (rangingfrom 1700 to 2400 M), but not acute high attitude hypoxia (above 4000 M), can effectively improve insulin sensitivity and glucose tolerance for humans and antagonizes the obese phenotype in animals with a genetic defect. In humans, the magnitude of the improvementvaries widely and correlates with baseline plasma DHEA-S levels. Compared to training at sea-level, training at altitude effectively decreases fat mass in parallel with increased muscle mass. This change may be associated with increased perfusion of insulin and fuel towards skeletal muscle that favors muscle competing postprandial fuel in circulation against adipose tissues.