• Title/Summary/Keyword: controlled-stress

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Systematic Review on Presbycusis Treated by Herbal Medicine Focusing on Kidney Deficiency (노인성 난청의 한약 치료에 대한 체계적 문헌고찰: 신허(腎虛)을 중점으로)

  • Lim, Hui-yeong;Jin, Han-Sol;Ko, Woo-Shin;Yoon, Hwa-Jung
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.34 no.4
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    • pp.49-70
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    • 2021
  • Objectives : This study was conducted to approve the effectiveness and safety of herbal medicine on presbycusis with kidney deficiency. Methods : We searched randomized controlled trials(RCTs) on presbycusis patients diagnosed with kidney deficiency through 10 electronic databases from the start to Sep 7, 2021. Study collection and data extraction, and evaluation of risk of bias were conducted by two independent collaborator. The evaluation of the risk of bias in included RCTs was carried out by using Cochrane risk-of-bias tool. And the data synthesis was conducted by using Review Manager(RevMan, ver.5.4). Results : 1. The treatment group which used herbal medicine(HM) alone was more effective than the control group which used only western medicine(WM) on effective rate of hearing loss. 2. In 3 studies comparing the HM-WM combination treatment group with the control groups using the same WM treatment, the effective rate was statistically significantly higher in the HM-WM combination treatment group. 3. Of the 5 studies that reported adverse reactions, one study reported mild nausea and dizziness, but the difference between the HM treatment group and the WM control group was not statistically significant, and no side effects occurred in other 3 studies. 4. In studies comparing HM and WM, the HM treatment group improved hearing loss, whole blood viscosity, serum TNF-𝛼, IL-1𝛽, IL-6, and oxidative stress indicators better than the WM control group, and there was no significant difference. 5. In studies comparing the HM-WM treatment group with the WM control group, the severity of tinnitus, quality of life, and feelings of anxiety and depression were better in the treatment group than the control group. Conclusions : This study shows that the herbal medicine can improve symptoms of presbycusis with kidney deficiency.

Predicting Habitat Suitability of Carnivorous Alert Alien Freshwater Fish (포식성 유입주의 어류에 대한 서식처 적합도 평가)

  • Taeyong, Shim;Zhonghyun, Kim;Jinho, Jung
    • Ecology and Resilient Infrastructure
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    • v.10 no.1
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    • pp.11-19
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    • 2023
  • Alien species are known to threaten regional biodiversity globally, which has increased global interest regarding introduction of alien species. The Ministry of Environment of Korea designated species that have not yet been introduced into the country with potential threat as alert alien species to prevent damage to the ecosystem. In this study, potential habitats of Esox lucius and Maccullochella peelii, which are predatory and designated as alert alien fish, were predicted on a national basis. Habitat suitability was evaluated using EHSM (Ecological Habitat Suitability Model), and water temperature data were input to calculate Physiological Habitat Suitability (PHS). The prediction results have shown that PHS of the two fishes were mainly controlled by heat or cold stress, which resulted in biased habitat distribution. E. lucius was predicted to prefer the basins at high latitudes (Han and Geum River), while M. peelii preferred metropolitan areas. Through these differences, it was expected that the invasion pattern of each alien fish can be different due to thermal preference. Further studies are required to enhance the model's predictive power, and future predictions under climate change scenarios are required to aid establishing sustainable management plans.

Diurnal Changes of Leaf Water Potential in Cuttings (삽수(挿穗)의 Leaf Water Potential의 변화(變化))

  • Hong, Sung Cheon
    • Journal of Korean Society of Forest Science
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    • v.38 no.1
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    • pp.27-32
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    • 1978
  • The diurnal pattern of leaf water potential in cuttings by Dye Method was as follows: 1. Diurnal pattern of leaf water potential (${\psi}_l$) in Viburnum Awabuki K. Koch and Daphne odora Thunb. was shown the pattern of the curves without mutual relation with soil classes when soil water potential (${\psi}_s$) was 0 bar. When ${\psi}_s$ was above -0.01 bar, the cuttings in the loamy sand (L.S.) was shown by the maximum values than that in sandy clay (S.C.) by about -1 bar gap (Fig. 1). 2. The diurnal changes of ${\psi}_l$ was shown the most high from two to eight O'clock in the morning, the maximum value was -3 bars when ${\psi}_s$ was above -0.01 to -0.02 bar, and was -4 bars below -0.03 bar. The diurnal the lowest values of ${\psi}_l$ showed -20 to -22 bars from one to two O'clock in the afternoon. In the fifteenth day after cutting V.A., the staying time in the diurnal maximum values of ${\psi}_l$ is about half in comparison with it in the fifth day. The curves of recovery of water stress (Fig. 1), the former reached to the diurnal maximum values -1 to -2 bars lately every hours comparing with it of the latter. The general diurnal pattern of ${\psi}_l$ was most clearly related to change with air temperature and the relative humitidy. 3. Comparing the treatment block by IAA 50 ppm with controlled block in fifteenth day after V.A. cuttings, in case of treatment reached to maximum values -2 to -3 bars lately as shown Fig. 2., and also staying times was only half in comparison with controlled block. 4. The cuttings 4 leafs was much rootings than 2 leafs in V.A. (Table. 1), and the former reached maximum value -2 to -3 bars lately every hours comparing with the latter. 5. In case of Buxus microphylla var. Koreana as shown Fig. 3., comparing the pattern curves of in the cuttings 8 leafs with 4 leafs, the former reached to maximum values -2 to -3 bars lately in comparison with the latter, but reffering to the amount of rooting (Table. 2), the former is less than the latter.

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Influence of Short-term Application of Abscisic Acid in Nutrient Solution on Growth and Drought Tolerance of Tomato Seedlings (토마토 육묘과정에서 단기간 ABA처리가 묘소질과 건조내성에 미치는 영향)

  • Kim, Il-Seop;Vu, Ngoc-Thang;Vo, Hoang-Tung;Choi, Ki-Young;Kim, Young Shik
    • Journal of Bio-Environment Control
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    • v.24 no.1
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    • pp.13-20
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    • 2015
  • This study was conducted to evaluate influence of short-term application of abscisic acid (ABA) in nutrient solution on growth and drought tolerance of tomato seedlings. The treatments included four ABA concentrations (0.5, 1, 2, $3mg{\cdot}L^{-1}$) and control (non-treatment) were applied to the nutrient solution in a hydroponic system. On the $5^{th}$ and $10^{th}$ day after growing in the nutrient solution containing ABA, seedlings were transferred to -5 bars of PEG-8000 in a growth chamber to induce water stress. Except for stem diameter and fresh and dry weight of root, there were no statistical differences in other growth parameters among control, 0.5 and $1mg{\cdot}L^{-1}$ of ABA treatments. Seedlings growths were strongly inhibited in nutrient solution containing 2 and $3mg{\cdot}L^{-1}$ of ABA. The root growth such as fresh and dry weigh of root, total root surface area, and average root diameter was slightly enhanced in $1mg{\cdot}L^{-1}$ of ABA treatment. The elevation of ABA concentrations in nutrient solution resulted in the decrease in transpiration rate and increase in stomatal diffusive resistance and leaf temperature of tomato seedlings. The initiations of seedling wilting after treating in -5 bars of PEG were delayed from 10 hrs in control to 30 hrs in ABA applied treatments. Additionally, the high percentages of recovered seedlings were observed in 0.5 and $1mg{\cdot}L^{-1}$ of ABA treatments after re-irrigation. Therefore, short-term application of $1mg{\cdot}L^{-1}$ of ABA in the nutrient solution stimulated the root growth and drought tolerance of tomato seedlings by delaying the start time of wilting point and enhancing the recovery after re-irrigation.

Review of Production, Husbandry and Sustainability of Free-range Pig Production Systems

  • Miao, Z.H.;Glatz, P.C.;Ru, Y.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.11
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    • pp.1615-1634
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    • 2004
  • A review was undertaken to obtain information on the sustainability of pig free-range production systems including the management, performance and health of pigs in the system. Modern outdoor rearing systems requires simple portable and flexible housing with low cost fencing. Local pig breeds and outdoor-adapted breeds for certain environment are generally more suitable for free-range systems. Free-range farms should be located in a low rainfall area and paddocks should be relatively flat, with light topsoil overlying free-draining subsoil with the absence of sharp stones that can cause foot damage. Huts or shelters are crucial for protecting pigs from direct sun burn and heat stress, especially when shade from trees and other facilities is not available. Pigs commonly graze on strip pastures and are rotated between paddocks. The zones of thermal comfort for the sow and piglet differ markedly; between 12-22$^{\circ}C$ for the sow and 30-37$^{\circ}C$ for piglets. Offering wallows for free-range pigs meets their behavioural requirements, and also overcomes the effects of high ambient temperatures on feed intake. Pigs can increase their evaporative heat loss via an increase in the proportion of wet skin by using a wallow, or through water drips and spray. Mud from wallows can also coat the skin of pigs, preventing sunburn. Under grazing conditions, it is difficult to control the fibre intake of pigs although a high energy, low fibre diet can be used. In some countries outdoor sows are fitted with nose rings to prevent them from uprooting the grass. This reduces nutrient leaching of the land due to less rooting. In general, free-range pigs have a higher mortality compared to intensively housed pigs. Many factors can contribute to the death of the piglet including crushing, disease, heat stress and poor nutrition. With successful management, free-range pigs can have similar production to door pigs, although the growth rate of the litters is affected by season. Piglets grow quicker indoors during the cold season compared to outdoor systems. Pigs reared outdoors show calmer behaviour. Aggressive interactions during feeding are lower compared to indoor pigs while outdoor sows are more active than indoor sows. Outdoor pigs have a higher parasite burden, which increases the nutrient requirement for maintenance and reduces their feed utilization efficiency. Parasite infections in free-range pigs also risks the image of free-range pork as a clean and safe product. Diseases can be controlled to a certain degree by grazing management. Frequent rotation is required although most farmers are keeping their pigs for a longer period before rotating. The concept of using pasture species to minimise nematode infections in grazing pigs looks promising. Plants that can be grown locally and used as part of the normal feeding regime are most likely to be acceptable to farmers, particularly organic farmers. However, one of the key concerns from the public for free-range pig production system is the impact on the environment. In the past, the pigs were held in the same paddock at a high stocking rate, which resulted in damage to the vegetation, nutrient loading in the soil, nitrate leaching and gas emission. To avoid this, outdoor pigs should be integrated in the cropping pasture system, the stock should be mobile and stocking rate related to the amount of feed given to the animals.

Characteristics of Growth, Yield, and Physiological Responses of Small-Sized Watermelons to Different Soil Moisture Contents Affected by Irrigation Starting Point in a Plastic Greenhouse (소형 수박 시설 재배 시 관수개시점에 따른 토양수분 함량별 생육, 수량 및 생리적 반응 특성 구명)

  • Huh, Yoon-Sun;Kim, Eun-Jeong;Noh, Sol-Ji;Jeon, Yu-Min;Park, Sung-Won;Yun, Geon-Sig;Kim, Tae-Il;Kim, Young-Ho
    • Journal of Bio-Environment Control
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    • v.29 no.4
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    • pp.388-398
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    • 2020
  • Watermelon yield mainly depends on soil water content controlled by irrigation in a plastic greenhouse. In this study, we investigated the effect of different soil moisture contents affected by irrigation starting point on growth, yield, and physiological responses of small-sized watermelons. Irrigation was initiated at 5 different levels of soil water content as a starting point with soil moisture detecting sensor after 14 days of transplanting, and stopped at 7 ~ 10 days before harvest. These treatments were compared with the conventional periodic irrigation as control. When soil had the lowest moisture content (-50 kPa), the overall shoot growth was retarded, but the root length and root dry weight increased. The photosynthetic parameters (photosynthetic rate, stomatal conductance, and transpiration rate) of watermelon leaves decreased significantly in the lowest soil moisture content (-50 kPa). On the other hand, the photosynthetic rates of watermelon leaves grown with irrigation starting point between -20 and -40 kPa were observed to be higher than those of other treatments. Fruit set rate and marketable fruit yield increased significantly at -30 kPa and -40 kPa. Proline, abscisic acid (ABA), total phenol and citrulline, which are known to contribute to stress tolerance under drought condition, increased as soil water content decreased, particularly, the largest increases were recorded at -50 kPa. From these results, it was found that an appropriate water supply adjusted with an irrigation starting point between -30 and -40 kPa could help to keep favorable soil water content during the cultivation of small-sized watermelons, promoting the marketable fruit production as well as inducing the vigorous plant growth and reproductive development.

Control of Stretching of Tomato (Lycopersicon esculentum Mill.) on Cylindrical Paper Pot Seedling Using High-Salinity Potassium Fertilizers (고농도 칼륨처리를 활용한 원통형 종이포트 토마토묘의 도장억제)

  • Xu, Chan;Kim, Si Hong;Kim, Dae Hoon;Kim, Jae Kyung;Heo, Jae Yun;Vu, Ngoc Thang;Choi, Ki Young;Kim, Il Seop;Jang, Dong Cheol
    • Journal of Bio-Environment Control
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    • v.29 no.4
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    • pp.354-364
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    • 2020
  • This study was conducted to examine the potential of inducing salinity stress on cylindrical paper pot tomato seedlings to inhibit overgrowth. Potassium fertilizers, sulfate of potash (K2SO4), muriate of potash (KCl), and monopotassium phosphate (KH2PO4), were prepared as two solutions of (5 and 10) dS·m-1 salinity level, respectively, to investigate the influence on tomato (Lycopersicon esculentum Mill.) seedling growth. We also investigated the adaptability and survivability of treated tomato seedlings with high-salinity potassium (10 dS·m-1 KCl) to harsh environmental conditions (water deficit, low temperature, and storage conditions). Repeated addition of high-salinity level KCl, K2SO4, or KH2PO4 markedly decreased the dry matter of shoot and root, leaf area, and net assimilate rates (NAR) but increased the stem diameter of seedlings. Among the three sources, the relative growth rate of plant height (RGRH) was most sensitive to KCl addition; increasing salinity levels of KCl solution decreased the RGRH of seedlings. The compactness, which directly reflects the stocky growth index, increased in KCl or KH2PO4 treatments. After a week's water deficit, severely wilted seedlings were observed in control seedlings (untreated with KCl), but no wilted seedlings were observed in the KCl treated seedlings, and the relative water content (RWC) of the untreated seedlings significantly decreased by 23 %, while that of the pretreated seedlings only decreased by 8 %. The increase in ion leakage of KCl treated seedlings at low temperatures was less than that of untreated seedlings. Furthermore, there was far lower damage proportion on pretreated seedlings at (9, 12, and 15)℃ storage temperatures after 20 days, compared with on unpretreated seedlings. Our results suggest that high-salinity potassium fertilizer, especially KCl, is effective in preventing tomato seedling overgrowth, while it also improves tolerance.

A Study on the Shear Characteristics of the Decomposed Granite Soils Using Direct Shear Test (직접전단시험(直接剪斷試驗)에 의한 화강토(花崗土)의 전단특성(剪斷特性)에 관(關)한 연구(硏究))

  • Lee, Dal Won;Kang, Yea Mook;Cho, Seong Seup
    • Korean Journal of Agricultural Science
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    • v.13 no.2
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    • pp.227-242
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    • 1986
  • This paper describes the observed behavior in the direct shear test on decomposed granite soil having the complicate engineering properties at various different levels of factors. The objectives of this study were to investigate the characteristics of the decomposed granite soil under controlled various moisture content, dry density, strain rate and soaking which give influence to the shear strength. The results were summarized as follows; 1. The shear strength was decreased remarkably with the increasing of moisture contents of A and B soil were 5-10% and 15-20% respectively. 2. Cohesion and angle of internal friction were decreased with the increasing of moisture content and increased with the increasing of dry density. 3. The shear strength was increased with the increasing of normal stress and volume change was decreased on the whole. The shear strength was generally increased with the increasing of the strain rate. 4. As dry density increases, A-soil shows the progressive failure and the decrease of volume change while B-soil shows the initial failure and the increase of volume change. 5. The relationships between the soaked and unsoaked specimens were as follows ; ${\tau}_f=0.1009+1.026{{\tau}_f}^*$ (A-soil), ${\tau}_f=0.1586+0.8005{{\tau}_f}^*$ (B-soil) 6. Angle of internal friction of the direct shear test shows larger value than that of the triaxial compression test. All effective stress path was nearly similar.

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EFFECT OF CROSS-SECTIONAL AREA OF 6 NICKEL-TITANIUM ROTARY INSTRUMENTS ON THE FATIGUE FRACTURE UNDER CYCLIC FLEXURAL STRESS: A FRACTOGRAPHIC ANALYSIS (반복 굽힘 스트레스 하에서 전동식 니켈-티타늄 파일의 단면적의 크기가 피로파절에 미치는 영향 : 파절역학 분석)

  • Hwang, Soo-Youn;Oh, So-Ram;Lee, Yoon;Lim, Sang-Min;Kum, Kee-Yeon
    • Restorative Dentistry and Endodontics
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    • v.34 no.5
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    • pp.424-429
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    • 2009
  • This study aimed to assess the influence of different cross-sectional area on the cyclic fatigue fracture of Ni-Ti rotary files using a fatigue tester incorporating cyclical axial movement. Six brands of Ni-Ti rotary files (ISO 30 size with. 04 taper) of 10 each were tested: Alpha system (KOMET), HeroShaper (MicroMega), K3 (SybronEndo), Mtwo (VDW), NRT (Mani), and ProFile (Dentsply). A fatigue-tester (Denbotix) was designed to allow cyclic tension and compressive stress on the tip of the instrument. Each file was mounted on a torque controlled motor (Aseptico) using a 1:20 reduction contra-angle and was rotated at 300 rpm with a continuous, 6 mm axial oscillating motion inside an artificial steel canal. The canal had a $60^{\circ}$ angle and a 5 mm radius of curvature. Instrument fracture was visually detected and the time until fracture was recorded by a digital stop watch. The data were analyzed statistically. Fractographic analysis of all fractured surfaces was performed to determine the fracture modes using a scanning electron microscope. Cross-sectional area at 3 mm from the tip of 3 unused Ni-Ti instruments for each group was calculated using Image-Pro Plus (Imagej 1.34n, NIH). Results showed that NRT and ProFile had significantly longer time to fracture compared to the other groups (p < .05). The cross-sectional area was not significantly associated with fatigue resistance. Fractographycally, all fractured surfaces demonstrated a combination of ductile and brittle fracture. In conclusion, there was no significant relationship between fatigue resistance and the cross-sectional area of Ni-Ti instruments under experimental conditions.

Tensile Properties of Hybrid Fiber Reinforced Cement Composite according to the Hooked & Smooth Steel Fiber Blending Ratio and Strain Rate (후크형 및 스무스형 강섬유의 혼합 비율과 변형속도에 따른 하이브리드 섬유보강 시멘트복합체의 인장특성)

  • Son, Min-Jae;Kim, Gyu-Yong;Lee, Sang-Kyu;Kim, Hong-Seop;Nam, Jeong-Soo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.25 no.3
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    • pp.31-39
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    • 2021
  • In this study, the fiber blending ratio and strain rate effect on the tensile properties synergy effect of hybrid fiber reinforced cement composite was evaluated. Hooked steel fiber(HSF) and smooth steel fiber(SSF) were used for reinforcing fiber. The fiber blending ratio of HSF+SSF were 1.5+0.5, 1.0+1.0 and 0.5+1.5vol.%. As a results, in the cement composite(HSF2.0) reinforced with HSF, as the strain rate increases, the tensile stress sharply decreased after the peak stress because of the decrease in the number of straightened pull-out fibers by increase of micro cracks in the matrix around HSF. When 0.5 vol.% of SSF was mixed, the micro cracks was effectively controlled at the static rate, but it was not effective in controlling micro cracks and improving the pull-out resistance of HSF at the high rate. On the other hand, the specimen(HSF1.0SSF1.0) in which 1.0vol.% HSF and 1.0vol.% SSF were mixed, each fibers controls against micro and macro cracks, and SSF improves the pull-out resistance of HSF effectively. Thus, the fiber blending effect of the strain capacity and energy absorption capacity was significantly increased at the high rate, and it showed the highest dynamic increase factor of the tensile strength, strain capacity and peak toughness. On the other hand, the incorporation of 1.5 vol.% SSF increases the number of fibers in the matrix and improves the pull-out resistance of HSF, resulting in the highest fiber blending effect of tensile strength and softening toughness. But as a low volume fraction of HSF which controlling macro crack, it was not effective for synergy of strain capacity and peak toughness.