• Title/Summary/Keyword: Heat Tolerance

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In vitro selection of lactic acid bacteria for probiotic use in pigs (양돈용 생균제 개발을 위한 유산균주 선발)

  • Byun, Jae-won;Kim, Gyung-tae;Bae, Hyoung-suk;Baek, Voung-jin;Lee, Wan-kyu
    • Korean Journal of Veterinary Research
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    • v.40 no.4
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    • pp.701-706
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    • 2000
  • This study was carried out to select the lactic acid bacteria(Lactobacillus, Streptococcus and Bifidobacterium) and yeast for probiotic use in pigs. Acid-tolerant 536 strains were isolated from the feces of 30 pigs. To select useful strains, the first screened strains were treated with strong acid solution(pH 2.5 to 3.0) for 3 hours and subsequentely treated with the anaerobic diluent solution containing 0.15% Oxgall for 3 hours. Among these strains, 151 strains showed strong tolerance to both acid and bile. Lactobacillus and Streptococcus tolerant to the acid and bile were treated with heat at $80^{\circ}C$ for 15 min, and at $70^{\circ}C$ for 5 min in Bifidobacterium and yeast. As a result of heat treatment, 38 strains were obtained as heat-tolerant strains. All of heat-tolerant strains were tested for antibiotic resistance against virginiamycin, sulfathiazole, aureomycin, neomycin, linsmycin, tiamulin and ASP250 which were used as feed additives for growth promotion in pigs. Finally, one strain each from Lactobacillus, Streptococcus, Bifidobacterium and yeast that showed resistance to acid, bile, heat and antibiotics was selected for probiotic use in pigs.

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Effect on the Human Thermoregulation of Wear Training in Air Condition (여름철 냉방 조건에서의 착의 훈련이 인체의 체온 조절 반응에 미치는 효과)

  • Kim, Mi-Kyung;Choi, Jeong-Wha;Yeom, Hee-gyong
    • Journal of the Korean Society of Clothing and Textiles
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    • v.19 no.3
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    • pp.504-515
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    • 1995
  • This study was performed to investigate that wear training using thermal insulation with clothes has the effect on the human thermoregulatory response, especially on the heat tolerance. Twelve men and women in twenties wert divided into the control group, the training groups and each group except the control group had participated in wear training. The heat tolerance was assessed in all subjects who had participated in the experiment carried out in hot environment(40$\pm$1$^{\circ}C$, 50$\pm$5%RH) by such parameters as rectal temperature, skin temperature, systolic blood pressure, diastolic blond pressure, plume rate, total sweat volume, local sweat volume, subjective sensation, and the differences of heat tolerance in each group were compared. The results were as follows: In hot environment(4$0^{\circ}C$) the changing width of rectal temperature was decreased in the control and the heavy clothing group. Forehead and abdomen temperature in hot environment were significantly decreased after the training. Sweat rate was higher after the training than before. In all experimental groups, systolic and diastolic blood pries.;uses in hot environment(4$0^{\circ}C$) were significantly decreased after the training.

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Cross-Resistance to Toluene and Heat in Micrococus sp. BCNU 121 (Micrococcus sp. BCNU 121균주의 toluene과 열에 대한 교차내성)

  • 주우홍;한수지;최용락;정영기
    • Journal of Life Science
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    • v.14 no.1
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    • pp.188-192
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    • 2004
  • Toluene tolerance and therrnotolerance in Crampositive organic solvent resistant bacterium Micrococcus sp. BCNU 121 has been studied. Exposure to a sub- lethal temperature or a sub-lethal concentration of toluene conferred protection to subsequent challenges with a killing temperature or a lethal concentration of toluene, respectively. Pretreatment of Micrococcus sp. BCNU 121 with sub-lethal concentrations of toluene induced adaptative protection against heat shock. Moreover, temperature-adaptative cells also showed cross-resistance to lethal doses of toluene. These data suggested a cross-regulation between toluene tolerance and heat shock response.

SHAPE OPTIMIZATION OF A Y-MIXING VANE IN NUCLEAR FUEL ASSEMBLY (핵연료 봉다발내 Y 혼합날개의 형상최적설계)

  • Jung, S.H.;Kim, K.Y.;Kim, K.H.;Park, S.K.
    • Journal of computational fluids engineering
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    • v.14 no.2
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    • pp.1-8
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    • 2009
  • The purposes of present work are to analyze the convective heat transfer with three-dimensional Reynolds-averaged Navier-Stokes analysis, and to optimize shape of the mixing vane taken tolerance into consideration by using the analysis results. Response surface method is employed as an optimization technique. The objective function is defined as a combination of heat transfer rate and inverse of pressure drop. Two bend angles of mixing vane are selected as design variables. Thermal-hydraulic performances have been discussed and optimum shape has been obtained as a function of weighting factor in the objective function. The results show that the optimized geometry improves the heat transfer performance far downstream of the mixing vane.

Time Course of Increased Cold Tolerance Resulting from Cool Clothing in Daily Life (착의훈련을 통해 향상된 내한능력의 지속성에 대한 연구)

  • 이종민
    • Journal of the Korean Society of Clothing and Textiles
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    • v.21 no.6
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    • pp.1003-1009
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    • 1997
  • To study the time course of increased cold tolerance, the physiological responses were measured during the course of a 2-yr study (Feb. 1995~Feb. 1996) of four female college students, whose cold tolerance was proved to be increased through wearing cool clothing in daily life from Sep. 1994 to Feb. 1995. To determine their cold tolerance, subjects rested at 25$\pm$1$^{\circ}C$, then were exposed to 15$\pm$1$^{\circ}C$, 50$\pm$5% R.H. for 90min in Feb. 1995 and Feb. 1996. Subjects' rectal temperatures, mean skin temperatures, heat production, shivering onset, thermal sensations, and comfort showed no significant changes, when they were measured in 1995 and 1996. Based on these results, we can safely assume that mild cold acclimatization coming from wearing cool clothing lasts at least oneyear, that is until the following year. One of the possible explanations for this is that the subjects did not increase their clothing thermalresistances after the cold acclimatization.

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In vitro selection of lactic acid bacteria for probiotic use in pig (양돈용 생균제 균주개발을 위한 유산균주 선발)

  • Ryu, Ji-Sook;Han, Sun-Kyung;Shin, Myeong-Soo;Lee, Wan-Kyu
    • Korean Journal of Veterinary Service
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    • v.32 no.1
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    • pp.33-41
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    • 2009
  • In order to develop probiotic strain for pigs, Lactobacillus spp. (527 isolates), Streptococcus spp. (95 isolates) and Bifidobacterium spp. (25 isolates) were isolated from the feces of 35 pigs. These isolates were tested through in vitro experiment such as acid tolerance at pH 2.0 (Lactobacillus spp. and Streptococcus spp.) or pH 3.0 (Bifidobacterium spp.), bile tolerance in MRS broth containing 0.3% (w/v) Oxgall, heat resistance at $70^{\circ}C$ and $80^{\circ}C$ for 5 min, antibiotic resistance, antimicrobial activity against pathogenic bacteria and Caco-2 cell adherence assay. Finally ten most superior strain (5 Lactobacillus spp. strain, 3 Bifidobacterium spp. strain and 2 Streptococcus spp. strain) were selected as potential candidate for probiotic use in pig industry. It could be used as an alternative to antibiotics in feed additives.

고속 주축의 열변형이 소음특성에 미치는 영향

  • 이찬흥;김태형;이후상
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.307-311
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    • 1997
  • This paper describes influence of thermal deformation on nosic characteristics in high speed spindle systems. Heat generation in front, rear spindle bearings and built in motor lead to diverse thermal deformation of headstock with time. This deformation changes assemble tolerance in bearing housing, especially to elliptic form. The elliptic assemble tolerance generate high nosie level with dominant amplitude in double rotational frequency.

Stress Tolerance of Bifidobacterium infantis ATCC 27920 to Mild-heat Adaptation

  • Kang, Seok-U;Kim, Young-Hoon;Cho, In-Shick;Kang, Ja-Heon;Chun, Il-Byung;Kim, Kwang-Hyun;Oh, Se-Jong
    • Food Science and Biotechnology
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    • v.18 no.1
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    • pp.249-252
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    • 2009
  • Two-dimensional gel electrophoresis (2-DE) was employed to assess the thermo-tolerance characteristics of Bifrdobacterium infantis ATCC 27920 to mild heat adaptation. When exposed to various heat levels, pH, and hydrogen peroxide ($H_2O_2$) stress conditions, B. infantis ATCC 27920 exhibited high level of stress resistance. Under mild-heat treatment ($46^{\circ}C$), no significant change in viability level was observed after 2 hr. Interestingly, improved viability was observed in mild-heat adapted ($46^{\circ}C$ for 1 hr) cultures exposed to $55^{\circ}C$, in comparison to control experiments. Viability was not affected by pH, bile, and $H_2O_2$ stress conditions. 2-DE analysis revealed those mild-heat adaptation up-regulated 4 proteins and down-regulated 3 proteins. Among these protein spots, isopropyhnalate dehydratase (leuD), glycosyltransferase (glgA), and ribosomal protein L5 (rp1E) were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALD1-TOF/MS).

Effect on the Compliance of Spindle -Bearing System by the Assembling Tolerance (축-베어링계의 컴플라이언스 특성에 미치는 조립공차의 영향)

  • 이강재;서장력;이선규
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1995.10a
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    • pp.995-999
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    • 1995
  • In spindle-bearing system, the displacement characteristics of the bearing by the load applied on the spindle are affected greatly by the assembling tolerance between the spindle and housing assembled to support the bearing. Also in spindle system of rotational operation, the compliance characteristic of the bearing is expected to be varied frequently by the thermal deformation of the spindle and the housing. To predict the thermal deformation of the spindle including heat generation of the bearing, we need to examine the effect on the compliance of spindle-bearing system by the assembling tolerance. In this paper, we proposed the load-displacement relation expression considering the effect which the variation of contact pressure due to the radial directional assembling tolerance between the bearing and the housing influences on the axial and radial directional displacement characteristics of the bearing. Furthermore, for several assembling systems of bearings and housings having all different assembling tolerances, we proposed a method to predict exactly the variation of the bearing preload which is sensitive to the thermal deformation by showing the propriety with experimental results.

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Phytohormnes producing Preussia sp. BSL-10 induce phytohormonal changes in tomato (Solanum lycopersium cv.) under divers temperature.

  • Al-Hosni, Khdija;Shahzad, Raheem;Kang, Sang-Mo;Lee, In-Jung
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.202-202
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    • 2017
  • Global climate change resulted in unwarranted change in global temperature and caused heat and cold stress, which are consider major threat to agriculture productivity around the world. The use of plant growth-promoting microbes is an eco-friendly strategy to counteract such stresses and confer tolerance to the plants. In current study, previously isolated endophytic fungi Preussia sp. BSL-10 has been found to produce phytohormones such as IAA and GA and as such, endophyte Preussia sp. BSL-10 found to induced tolerance against heat and cold stress. The results showed that under both heat and cold stress the plant growth parameter such as shoot, root length, shoot fresh weight and root fresh weight is higher in Preussia sp. BSL-10 treated plants as compare to free Preussia sp. BSL-10 control plants. In addition, the stress-sensitive endogenous ABA levels were significantly increased in Preussia sp. BSL-10 host plant. The current result suggest that the phytohormone-producing endophyte Preussia sp. BSL-10 can increase plant resistance toheat and cold stress, in turn improving agricultural productivity.

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