• Title/Summary/Keyword: R170

Search Result 529, Processing Time 0.028 seconds

Screening and Application of Bacillus Strains Isolated from Nonrhizospheric Rice Soil for the Biocontrol of Rice Blast

  • Sha, Yuexia;Zeng, Qingchao;Sui, Shuting
    • The Plant Pathology Journal
    • /
    • v.36 no.3
    • /
    • pp.231-243
    • /
    • 2020
  • Rice blast, caused by Magnaporthe oryzae, is one of the most destructive rice diseases worldwide. The aim of this study was to screen bacterial isolates to efficiently prevent the occurrence of rice blast. A total of 232 bacterial isolates were extracted from nonrhizospheric rice soil and were screened for antifungal activity against M. oryzae using a leaf segment assay. Strains S170 and S9 showed significant antagonistic activity against M. oryzae in vitro and in leaf disk assays, and controlled M. oryzae infection under greenhouse conditions. The results showed that strains S170 and S9 could effectively control rice leaf blast and panicle neck blast after five spray treatments in field. This suggested that the bacterial strains S170 and S9 were valuable and promising for the biocontrol of rice disease caused by M. oryzae. Based on 16S rDNA, and gyrA and gyrB gene sequence analyses, S170 and S9 were identified as Bacillus amyloliquefaciens and B. pumilus, respectively. The research also demonstrated that B. amyloliquefaciens S170 and B. pumilus S9 could colonize rice plants to prevent pathogenic infection and evidently suppressed plant disease caused by 11 other plant pathogenic fungi. This is the first study to demonstrate that B. amyloliquefaciens and B. pumilus isolated from nonrhizospheric rice soil are capable of recolonizing internal rice stem tissues.

Design of Structure Corners restraining Tribological Failures: Part II - Analysis of Design Parameters and Examples (트라이볼로지 손상을 억제하기 위한 구조물 모서리부 설계: 제2부 - 설계인자 분석 및 예)

  • Kim, Hyung-Kyu
    • Tribology and Lubricants
    • /
    • v.31 no.4
    • /
    • pp.170-176
    • /
    • 2015
  • As a continuation of Part I, which developed a design formula of the minimum corner radius (Rmin) for restraining tribological failures, Part II investigates design parameters such as material properties and contact force. As design examples, Al 7075-T651, SST 304 and HT-9 are chosen for the materials and 1, 10 and 100 kN are used for the forces. The results show that the difference in Rmin decreases as either the elastic modulus increases or the contact force decreases. Given the same material and force, the permissible Rmin decreases as the flat region increases and vice versa. Because the Rmin values obtained from the examples are very small, the dimensions of the corner radius normally designed in engineering structures are regarded acceptable. The von Mises stress evaluated for a typical example, which is far below the yield strength, confirms this interpretation. Nevertheless, the present work can provide a design criterion as well as a guideline for quality control in the manufacturing of, in particular, contact corners, which has not been attempted before to the best of the author’s knowledge. In addition, this paper considers the problem of a step that may be formed in the contact contour by using a similar approach. The result shows that no size of the step is permissible.

Magnetic Properties and Workability of Fe-Si Alloy Powder Cores

  • Lee, Tae-Kyung;Kim, Gu-Hyun;Choi, Gwang-Bo;Jeong, In-Bum
    • Journal of Magnetics
    • /
    • v.13 no.4
    • /
    • pp.170-172
    • /
    • 2008
  • Fe-6.5% Si alloys have good magnetic properties due to their high electrical resistivity, very low magneto-striction, and low crystalline anisotropy. Despite their strong potential, these alloys have seldom been used in magnetic applications because of the very poor ductility of Si-steel above 3.0 wt% Si [1-4]. It is difficult to achieve compressed Fe-6.5% Si powder cores with excellent properties because of the low density due to poor ductility. In compressed powder cores, high density is essential in order to obtain high magnetization and permeability. In this study, an attempt was made to produce Fe-3%Si powder cores because the Fe-3.0 wt% Si alloys have relatively good magnetic properties and room temperature ductility. Gas atomized Fe-3.0 wt% Si powder was compressed into toroid shape cores. By reducing the Si content to 3.0 wt%, the hysteresis loss could be greatly reduced and thus the total core loss could be minimized. The total core loss is 600 mW/$cm^3$ at 0.1 T and 50 kHz.

Repetitive Transcranial Magnetic Stimulation Combined with Task Oriented Training to Improve Upper Extremity Function After Stroke

  • Kim, Myoung-Kwon
    • Journal of Magnetics
    • /
    • v.19 no.2
    • /
    • pp.170-173
    • /
    • 2014
  • The purpose of the present study was to investigate the effect of repetitive transcranial magnetic stimulation (rTMS) in conjunction with task oriented training, on cortical excitability and upper extremity function recovery in stroke patients. This study was conducted with 31 subjects who were diagnosed as a hemiparesis by stroke. Participants in the experimental (16 members) and control groups (15 members) received rTMS and sham rTMS, respectively, during a 10 minutes session, five days per week for four weeks, followed by task oriented training during a 30 minutes session, five days per week for four weeks. Motor cortex excitability was performed by motor evoked potential and upper limb function was evaluated by motor function test. Both groups showed a significant increment in motor function test and amplitude, latency in motor evoked potential compared to pre-intervention (p < 0.05). A significant difference in post-training gains for the motor function test, amplitude in motor evoked potential was observed between the experimental group and the control group (p < 0.05). The findings of the current study demonstrated that incorporating rTMS in task oriented training may be beneficial in improving the effects of stroke on upper extremity function recovery.

The development of ultra-high frequency ultra-wide bandwidth sensor for Partial Discharge monitoring in Gas Insulated Switchgears (GIS 부분방전 검출용 극초단파 초광대역 센서 개발)

  • Kim, Young-Ro;Choi, Jae-Ok;Lee, Young-Sang;Kang, Chang-Won;Park, Ki-Jun;Goo, Sun-Geun;Yoon, Jin-Yul
    • Proceedings of the KIEE Conference
    • /
    • 2004.05b
    • /
    • pp.113-116
    • /
    • 2004
  • We developed internal and external type sensor to measure ultra-high frequency (UHF) partial discharge (PD) in 170 kV gas-insulated switchgears (GIS). We also manufactured a PD-generator to verify and measure the detection sensitivity of those sensors. We measured the output power of the UHF PD sensors induced by PDs of 5 pC using the PD-generator. We measured UHF propagation loss of an 170 kV GIS for optimal arrangement of the sensors. We used swept UHF signal from a network analyzer into the GIS to measure the loss of various components of the GIS.

  • PDF

Predictions of VO2max Using Metabolical Responses in Submaximal Exercise and 1,200 m Running for Male, and the Validity of These Prediction Models (성인 남성의 최대하 운동시 대사반응 및 1,200 m 달리기 기록을 이용한 최대산소섭취량 추정식 개발 및 타당도)

  • Im, J.H.;Jeon, Y.J.;Jang, H.K.;Kim, H.J.;Kim, K.H.;Lee, B.K.
    • Exercise Science
    • /
    • v.21 no.2
    • /
    • pp.231-242
    • /
    • 2012
  • The purpose of this study was to develop the prediction model of VO2max using submaximal metabolic responses from the Bruce protocol, HR responses at several stages and 1,200 m running record, and to compare and analyse the validity of these prediction models. The subjects were consisted of 255 male(133 male for 1,200 m running). They were participated maximal exercise testing with Bruce protocol, and the metabolic responses were measured in the end of the first(3 minute), second stage(6 minute), and 1,200 m running record. Measurement items were VO2(㎖/kg/min), VCO2(㎖/kg/min), VE(L/min), HR(bpm) of 3 and 6 minute, time to HR 150 bpm and 170 bpm, HR difference between Bruce protocol 6 and 3 minute, 1,200 m running record. Analyzing with all variables using enter method, the multiple R of total variable model was 0.642(p<.01), SEE was 4.38 ㎖/kg/min, CV was 10.8 %, but multicolinearity was appeared. The multiple R of 3 minutes model 1 and model 2 were 0.341 and 0.461, SEE was 6.05 and 5.72 ㎖/kg/min, CV was 14.9 and 14.1%, and multicolinearity did not appeared. The multiple R of 6 minutes model 1 and model 2 were 0.350 and 0.456, SEE was 6.03 and 5.74 ㎖/kg/min, CV was 14.9 and 14.2%, and multicolinearity did not appeared. The R of HR 170 and HR 170 model were 0.151 and 0.154, SEE were 6.36~6.37 ㎖/kg/min, CV were 15.7%. The R of 1,200 m running model was 0.444, SEE was 4.82 ㎖/kg/min, CV were 11.9%. In conclusion, with considering usefulness and convenience through the validity of these prediction models, the prediction model of VO2max recommended 6 and 3 minute model, and the validity of HR model and 1,200 m running model were moderately low.

Functional characterizations of residues Arg-158 and Tyr-170 of the mosquito-larvicidal Bacillus thuringiensis Cry4Ba

  • Leetachewa, Somphob;Moonsom, Saengduen;Chaisri, Urai;Khomkhum, Narumol;Yoonim, Nonglak;Wang, Ping;Angsuthanasombat, Chanan
    • BMB Reports
    • /
    • v.47 no.10
    • /
    • pp.546-551
    • /
    • 2014
  • The insecticidal activity of Bacillus thuringiensis (Bt) Cry toxins involves toxin stabilization, oligomerization, passage across the peritrophic membrane (PM), binding to midgut receptors and pore-formation. The residues Arg-158 and Tyr-170 have been shown to be crucial for the toxicity of Bt Cry4Ba. We characterized the biological function of these residues. In mosquito larvae, the mutants R158A/E/Q (R158) could hardly penetrate the PM due to a significantly reduced ability to alter PM permeability; the mutant Y170A, however, could pass through the PM, but degraded in the space between the PM and the midgut epithelium. Further characterization by oligomerization demonstrated that Arg-158 mutants failed to form correctly sized high-molecular weight oligomers. This is the first report that Arg-158 plays a role in the formation of Cry4Ba oligomers, which are essential for toxin passage across the PM. Tyr-170, meanwhile, is involved in toxin stabilization in the toxic mechanism of Cry4Ba in mosquito larvae.