• Title/Summary/Keyword: Loop Detection

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Development of a lateral flow dipstick test for the detection of 4 strains of Salmonella spp. in animal products and animal production environmental samples based on loop-mediated isothermal amplification

  • Wirawan Nuchchanart;Prapasiri Pikoolkhao;Chalermkiat Saengthongpinit
    • Animal Bioscience
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    • v.36 no.4
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    • pp.654-670
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    • 2023
  • Objective: This study aimed to develop loop-mediated isothermal amplification (LAMP) combined with lateral flow dipstick (LFD) and compare it with LAMP-AGE, polymerase chain reaction (PCR), and standard Salmonella culture as reference methods for detecting Salmonella contamination in animal products and animal production environmental samples. Methods: The SalInvA01 primer, derived from the InvA gene and designed as a new probe for LFD detection, was used in developing this study. Adjusting for optimal conditions by temperature, time, and reagent concentration includes evaluating the specificity and limit of detection. The sampling of 120 animal product samples and 350 animal production environmental samples was determined by LAMP-LFD, comparing LAMP-AGE, PCR, and the culture method. Results: Salmonella was amplified using optimal conditions for the LAMP reaction and a DNA probe for LFD at 63℃ for 60 minutes. The specificity test revealed no cross-reactivity with other microorganisms. The limit of detection of LAMP-LFD in pure culture was 3×102 CFU/mL (6 CFU/reaction) and 9.01 pg/μL in genomic DNA. The limit of detection of the LAMP-LFD using artificially inoculated in minced chicken samples with 5 hours of pre-enrichment was 3.4×104 CFU/mL (680 CFU/reaction). For 120 animal product samples, Salmonella was detected by the culture method, LAMP-LFD, LAMP-AGE, and PCR in 10/120 (8.3%). In three hundred fifty animal production environmental samples, Salmonella was detected in 91/350 (26%) by the culture method, equivalent to the detection rates of LAMP-LFD and LAMP-AGE, while PCR achieved 86/350 (24.6%). When comparing sensitivity, specificity, positive predictive value, and accuracy, LAMP-LFD showed the best results at 100%, 95.7%, 86.3%, and 96.6%, respectively. For Kappa index of LAMP-LFD, indicated nearly perfect agreement with culture method. Conclusion: The LAMP-LFD Salmonella detection, which used InvA gene, was highly specific, sensitive, and convenient for identifying Salmonella. Furthermore, this method could be used for Salmonella monitoring and primary screening in animal products and animal production environmental samples.

System Thinking on Diabetes Prevention and Management (당뇨병 예방 및 관리의 시스템 사고)

  • Noh, Young-Min;Lee, Ji-Uhn;Park, Jun-Hee;Choi, Nam-Hee;Homer, Jack B.;Yun, Eun-Kyoung
    • Korean System Dynamics Review
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    • v.17 no.1
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    • pp.25-40
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    • 2016
  • This research aims to identify important variables and their effects on diabetes prevention or progression from prediabetes to diabetic complication using system thinking. Based on the existing studies, we have constructed a causal loop diagram explaining dynamics of diabetes and have found 7 important reinforcing loops and 3 balancing loops in the causal loop diagram. The CLD displays an effect of increasing prediabetes early detection and awareness on diabetes prevention. The findings indicate that the projects in Korea for reducing incidence of diabetes and potential risk of complication have focused on variables which are related only on diabetes even though prediabetes has been a critical point on diabetes prevention and management. Thus, it also concludes that the effect of projects focusing only on diabetes have faced limitation to manage diabetes accordingly.

Implementation of High-Resolution Laser Distance Measurement System using Phase-Shift Method (위상천이 방법을 이용한 고분해능 레이저 거리측정 시스템 개발)

  • Park, Bee-Jay;Lee, Chung-Woo;Chung, Chung-Choo;Sho, Jae-Hyuk;Ong, Sang-Jin
    • Proceedings of the KIEE Conference
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    • 2004.11c
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    • pp.589-591
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    • 2004
  • In this paper, we developed a laser distance measurement(LDM) system based on DSP. We applied PPD(Pulsed Phase Detection) algorithm to the LDM system. The PPD algorithm calculate the distance from the LDM system to the object by using phase detection. Reference waveform at a fixed frequency is sampled by both the inner-loop and outer-loop pulse signal. The LDM system detects the difference of phase between the sampled signals. We obtained an accuracy of ${\sigma}=25.5mm$ from the LDM system.

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An Enhanced Architecture of CMOS Phase Frequency Detector to Increase the Detection Range

  • Thomas, Aby;Vanathi, P.T.
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.2
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    • pp.198-201
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    • 2014
  • The phase frequency detector (PFD) is one of the most important building blocks of a phase locked Loop (PLL). Due to blind-zone problem, the detection range of the PFD is low. The blind zone of a PFD directly depends upon the reset time of the PFD and the pre-charge time of the internal nodes of the PFD. Taking these two parameters into consideration, a PFD is designed to achieve a small blind zone closer to the limit imposed by process-voltage-temperature variations. In this paper an enhanced architecture is proposed for dynamic logic PFD to minimize the blind-zone problem. The techniques used are inverter sizing, transistor reordering and use of pre-charge transistors. The PFD is implemented in 180 nm technology with supply voltage of 1.8 V.

A Study on the Detection of a moving Object using Self-Loop Diffusion Neural Network (자기궤환 확산신경망을 이용한 이동물체의 검출에 관한 연구.)

  • Lee, Bong-Kyu;Shin, Suk-Kyun;Lee, Jae-Ho;Kim, Jin-Su;Lee, Key-Seo
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.397-401
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    • 1997
  • In this paper, we propose a neural-network that detects moving objects in an image using a diffusion neural network. The proposed neural network is improved by adding a self loop to diffusion layer to remove the noise in an image and to reduce the detection of phantom edge. Computer simulation with real images show that the proposed neural network can extract edges of moving object efficiently.

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Spatial Multiuser Access for Reverse Link of Multiuser MIMO Systems

  • Shin, Oh-Soon
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.10A
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    • pp.980-986
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    • 2008
  • Spatial multiuser access is investigated for the reverse link of multiuser multiple-input multiple-output (MIMO) systems. In particular, we consider two alternative a aches to spatial multiuser access that adopt the same detection algorithm at the base station: one is a closed-loop approach based on singular value decomposition (SVD) of the channel matrix, whereas the other is an open-loop approach based in space-time block coding (STBC). We develop multiuser detection algorithms for these two spatial multiuser access schemes based on the minimum mean square error (MMSE) criterion. Then, we compare the bit error rate (BER) performance of the two schemes and a single-user MIMO scheme. Interestingly, it is found that the STBC approach can provide much better BER performance than the SVD approach as well as than a single-user MIMO scheme.

Novel Mutations in the Displacement Loop of Mitochondrial DNA are Associated with Acute Lymphoblastic Leukemia: A Genetic Sequencing Study

  • Yacoub, Haitham Ahmed;Mahmoud, Wael Mahmoud;El-Baz, Hatim Alaa El-Din;Eid, Ola Mohamed;ELfayoumi, Refaat Ibrahim;Elhamidy, Salem Mohamed;Mahmoud, Maged M.
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.21
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    • pp.9283-9289
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    • 2014
  • Background: Acute lymphoblastic leukemia (ALL) is the most common cancer diagnosed in children and represents approximately 25% of cancer diagnoses among those younger than 15 years of age. Materials and Methods: This study investigated alterations in the displacement loop (d-loop) region of mitochondrial DNA (mtDNA) as a risk factor and diagnostic biomarker for early detection and diagnosis of acute lymphoblastic leukemia. Using mtDNA from 23 subjects diagnosed with acute lymphoblastic leukemia, the first 450 bp of the d-loop region were amplified and successfully sequenced. Results: This revealed 132 mutations at 25 positions in this region, with a mean of 6 alterations per subject. The d-loop alterations in mtDNA in subjects were all identified as single nucleotide polymorphisms in a homoplasmic distribution pattern. Mutant alleles were observed in all subjects with individual frequency rates of up to 95%. Thirteen mutant alleles in the d-loop region of mtDNA occurred with a high frequency. Novel alleles and locations were also identified in the d-loop of mtDNA as follows: 89 G insertions (40%), 95 G insertions (13%), 182 C/T substitutions (5%), 308 C insertions (19%), and 311 C insertions (80%). The findings of this study need to be replicated to be confirmed. Conclusions: Further investigation of the relationship between mutations in mitochondrial d-loop genes and incidence of acute lymphoblastic leukemia is recommended.

Comparison of Polymerase Chain Reaction, Real-time Polymerase Chain Reaction, and Loop-Mediated Isothermal Amplification for the Detection of Cronobacter sakazakii in Milk Powder (분유에 오염된 Cronobacter sakazakii 검출을 위한 중합효소연쇄반응, 실시간중합효소연쇄반응, 등온검출법의 비교)

  • Kim, Young-Joo;Seo, Sheungwoo;Wang, Xiaoyu;Seo, Dong Joo;Lee, Min Hwa;Son, Na Ry;Lee, Bog-Hieu;Choi, Changsun
    • Food Science of Animal Resources
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    • v.33 no.5
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    • pp.610-616
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    • 2013
  • Loop-mediated isothermal amplification (LAMP) is an emerging detection technology for the amplification of DNA under isothermal conditions. The aim of this study was to develop a rapid and reliable LAMP technique for the detection of Cronobacter sakazakii in milk powder. In order to enhance the sensitivity and specificity, LAMP primers targeting outer membrane protein A (ompA) gene of C. sakazakii were designed using Explorer V4 software. Thirty seven C. sakazakii strains and 13 pathogenic microorganisms were used for comparative detection of C. sakazakii using polymerase chain reaction (PCR), real-time PCR, and LAMP. LAMP developed in this study could specifically detect C. sakazakii strains without cross-reactivity with other foodborne pathogens. LAMP products amplified from ompA gene of C. sakazakii were digested with with HhaI and NruI enzyme. The specificity of LAMP was confirmed by restriction fragment length polymorphism (RFLP) analysis. LAMP could detect C. sakazakii within 1 h without bacterial culture and its detection limit was as low as 1 CFU/mL C. sakazakii in milk. In the comparison of the sensitivity, LAMP showed 10,000- and 100-times higher detection limit than PCR or real-time PCR, respectively. Therefore, this study can conclude that LAMP is a rapid and reliable detection technique for C. sakazakii contaminated in powdered milk.

A Study on the Improvement of Water-Leakage Detection Reliability in Local Heating System (지역난방배관의 누수감지 신뢰성 향상에 관한 연구)

  • 신춘식;안영주;변기식
    • Journal of the Korean Society of Safety
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    • v.14 no.1
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    • pp.66-72
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    • 1999
  • Local heating transportation pipe has sensor and return lines to detect water-leakage. There are impulse and resistance comparison measurement types for a water-leakage detection. The impulse type shows large detection error within a measurement range. Since the resistance comparison type can find a comparative accurate single water-leakage point in the measurement range of heating pipe, it has been used to detect water-leakages these days. However if the multi water-leakages are happened in the measurement range of transportation pipe. the resistance comparison type shows a detection error point by the parallel resistance between a detection sensor line and ground. But the detection error will be minimized by the divided transportation pipe loops. In this research, it suggests the design of remote controlled detection system which can divide a large pipe loop and a possible single water-leakage measurement process in each divided loops.

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Digital Fine Timing Tracker for Correlation Detection Receiver in IR-UWB Communication System (IR-UWB 시스템에서 상관 검출 수신기를 위한 디지털 미세 타이밍 추적기)

  • Ko Seok-Jun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.9C
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    • pp.905-913
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    • 2006
  • In the impulse radio ultra-wideband communication systems, the residual timing offset exists when the acquisition and tracking of the timing synchronization is well done. And the offset affects the performance of the system dramatically. In order to compensate the offset, we present the digital phase-locked loop that uses the reference signal in the correlation detection receiver. First, we show the degradation of BER performance that is caused by the offset, and then compensation process of the timing tracker and performance improvement. In this paper, the timing detector in the tracker operates at the sampling period of frame level uses the correlation between received and reference signal. Also, we present the performance comparison by using the computer simulation results for different Gaussian monocycle pulses.