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Sample records for pcr-free method detects

  1. PCR-free quantitative detection of genetically modified organism from raw materials. An electrochemiluminescence-based bio bar code method.

    PubMed

    Zhu, Debin; Tang, Yabing; Xing, Da; Chen, Wei R

    2008-05-15

    A bio bar code assay based on oligonucleotide-modified gold nanoparticles (Au-NPs) provides a PCR-free method for quantitative detection of nucleic acid targets. However, the current bio bar code assay requires lengthy experimental procedures including the preparation and release of bar code DNA probes from the target-nanoparticle complex and immobilization and hybridization of the probes for quantification. Herein, we report a novel PCR-free electrochemiluminescence (ECL)-based bio bar code assay for the quantitative detection of genetically modified organism (GMO) from raw materials. It consists of tris-(2,2'-bipyridyl) ruthenium (TBR)-labeled bar code DNA, nucleic acid hybridization using Au-NPs and biotin-labeled probes, and selective capture of the hybridization complex by streptavidin-coated paramagnetic beads. The detection of target DNA is realized by direct measurement of ECL emission of TBR. It can quantitatively detect target nucleic acids with high speed and sensitivity. This method can be used to quantitatively detect GMO fragments from real GMO products.

  2. PCR-Free Detection of Genetically Modified Organisms Using Magnetic Capture Technology and Fluorescence Cross-Correlation Spectroscopy

    PubMed Central

    Zhou, Xiaoming; Xing, Da; Tang, Yonghong; Chen, Wei R.

    2009-01-01

    The safety of genetically modified organisms (GMOs) has attracted much attention recently. Polymerase chain reaction (PCR) amplification is a common method used in the identification of GMOs. However, a major disadvantage of PCR is the potential amplification of non-target DNA, causing false-positive identification. Thus, there remains a need for a simple, reliable and ultrasensitive method to identify and quantify GMO in crops. This report is to introduce a magnetic bead-based PCR-free method for rapid detection of GMOs using dual-color fluorescence cross-correlation spectroscopy (FCCS). The cauliflower mosaic virus 35S (CaMV35S) promoter commonly used in transgenic products was targeted. CaMV35S target was captured by a biotin-labeled nucleic acid probe and then purified using streptavidin-coated magnetic beads through biotin-streptavidin linkage. The purified target DNA fragment was hybridized with two nucleic acid probes labeled respectively by Rhodamine Green and Cy5 dyes. Finally, FCCS was used to detect and quantify the target DNA fragment through simultaneously detecting the fluorescence emissions from the two dyes. In our study, GMOs in genetically engineered soybeans and tomatoes were detected, using the magnetic bead-based PCR-free FCCS method. A detection limit of 50 pM GMOs target was achieved and PCR-free detection of GMOs from 5 µg genomic DNA with magnetic capture technology was accomplished. Also, the accuracy of GMO determination by the FCCS method is verified by spectrophotometry at 260 nm using PCR amplified target DNA fragment from GM tomato. The new method is rapid and effective as demonstrated in our experiments and can be easily extended to high-throughput and automatic screening format. We believe that the new magnetic bead-assisted FCCS detection technique will be a useful tool for PCR-free GMOs identification and other specific nucleic acids. PMID:19956680

  3. PCR-free detection of genetically modified organisms using magnetic capture technology and fluorescence cross-correlation spectroscopy.

    PubMed

    Zhou, Xiaoming; Xing, Da; Tang, Yonghong; Chen, Wei R

    2009-11-26

    The safety of genetically modified organisms (GMOs) has attracted much attention recently. Polymerase chain reaction (PCR) amplification is a common method used in the identification of GMOs. However, a major disadvantage of PCR is the potential amplification of non-target DNA, causing false-positive identification. Thus, there remains a need for a simple, reliable and ultrasensitive method to identify and quantify GMO in crops. This report is to introduce a magnetic bead-based PCR-free method for rapid detection of GMOs using dual-color fluorescence cross-correlation spectroscopy (FCCS). The cauliflower mosaic virus 35S (CaMV35S) promoter commonly used in transgenic products was targeted. CaMV35S target was captured by a biotin-labeled nucleic acid probe and then purified using streptavidin-coated magnetic beads through biotin-streptavidin linkage. The purified target DNA fragment was hybridized with two nucleic acid probes labeled respectively by Rhodamine Green and Cy5 dyes. Finally, FCCS was used to detect and quantify the target DNA fragment through simultaneously detecting the fluorescence emissions from the two dyes. In our study, GMOs in genetically engineered soybeans and tomatoes were detected, using the magnetic bead-based PCR-free FCCS method. A detection limit of 50 pM GMOs target was achieved and PCR-free detection of GMOs from 5 microg genomic DNA with magnetic capture technology was accomplished. Also, the accuracy of GMO determination by the FCCS method is verified by spectrophotometry at 260 nm using PCR amplified target DNA fragment from GM tomato. The new method is rapid and effective as demonstrated in our experiments and can be easily extended to high-throughput and automatic screening format. We believe that the new magnetic bead-assisted FCCS detection technique will be a useful tool for PCR-free GMOs identification and other specific nucleic acids.

  4. A PCR-free fluorescence strategy for detecting telomerase activity via double amplification strategy.

    PubMed

    Zhang, Xiafei; Cheng, Rui; Shi, Zhilu; Jin, Yan

    2016-01-15

    As a universal tumor biomarker, research on the activity and inhibition of telomerase is of great importance for cancer diagnosis and therapy. Although the telomeric repeat amplification protocol (TRAP) has served as a powerful assay for detecting telomerase activity, its application has been significantly limited by amplification related errors and time-consuming procedure. To address the limitations of PCR-based protocol, a dual amplification fluorescence assay was developed for PCR-free detecting telomerase activity. Briefly, we designed an arch-structure DNA probe to specifically control strand displacement reaction and subsequent enzyme-aided amplification. Telomerase substrate (TS) primer was extended by telomerase to form long elongation products which contain several TTAGGG repeat units. So, one elongation product can release more than one trigger DNA (t-DNA) via strand displacement reaction to realize first amplification. Subsequently, t-DNA specifically opened molecular beacon (MB) to restore the fluorescence of MB. Meanwhile, t-DNA was recycled by the aid of nicking endonuclease to continuously open more and more MBs, leading to a second amplification. Owing to the double amplification strategy, the proposed method allowed the measurement of telomerase activity in crude cell extracts equivalent to 5 HeLa cells and 10 CCRF-CEM cells without PCR amplification. Besides, the influence of telomere-binding ligands on the telomerase activity demonstrated that the proposed method holds the potential to evaluate the inhibition efficiency of telomerase inhibitors.

  5. Detection of long repeat expansions from PCR-free whole-genome sequence data.

    PubMed

    Dolzhenko, Egor; van Vugt, Joke J F A; Shaw, Richard J; Bekritsky, Mitchell A; van Blitterswijk, Marka; Narzisi, Giuseppe; Ajay, Subramanian S; Rajan, Vani; Lajoie, Bryan; Johnson, Nathan H; Kingsbury, Zoya; Humphray, Sean J; Schellevis, Raymond D; Brands, William J; Baker, Matt; Rademakers, Rosa; Kooyman, Maarten; Tazelaar, Gijs H P; van Es, Michael A; McLaughlin, Russell; Sproviero, William; Shatunov, Aleksey; Jones, Ashley; Al Khleifat, Ahmad; Pittman, Alan; Morgan, Sarah; Hardiman, Orla; Al-Chalabi, Ammar; Shaw, Chris; Smith, Bradley; Neo, Edmund J; Morrison, Karren; Shaw, Pam; Reeves, Catherine; Winterkorn, Lara; Wexler, Nancy S; Housman, David E; Ng, Christopher W; Li, Alina L; Taft, Ryan J; van den Berg, Leonard H; Bentley, David R; Veldink, Jan H; Eberle, Michael A

    2017-09-08

    Identifying large expansions of short tandem repeats (STRs) such as those that cause amyotrophic lateral sclerosis (ALS) and fragile X syndrome is challenging for short-read whole-genome sequencing (WGS) data. A solution to this problem is an important step towards integrating WGS into precision medicine. We have developed a software tool called ExpansionHunter that, using PCR-free WGS short-read data, can genotype repeats at the locus of interest, even if the expanded repeat is larger than the read length. We applied our algorithm to WGS data from 3,001 ALS patients who have been tested for the presence of the C9orf72 repeat expansion with repeat-primed PCR (RP-PCR). Compared against this truth data, ExpansionHunter correctly classified all (212/212, 95% CI [0.98, 1.00]) of the expanded samples as either expansions (208) or potential expansions (4). Additionally, 99.9% (2,786/2,789, 95% CI [0.997, 1.00]) of the wild type samples were correctly classified as wild type by this method with the remaining three samples identified as possible expansions. We further applied our algorithm to a set of 152 samples where every sample had one of eight different pathogenic repeat expansions including those associated with fragile X syndrome, Friedreich's ataxia and Huntington's disease and correctly flagged all but one of the known repeat expansions. Thus, ExpansionHunter can be used to accurately detect known pathogenic repeat expansions and provides researchers with a tool that can be used to identify new pathogenic repeat expansions. The software is licensed under GPL v3.0 and the source code is freely available on GitHub. Published by Cold Spring Harbor Laboratory Press.

  6. Toward PCR-free mutation detection based on surface-enhanced Raman scattering

    NASA Astrophysics Data System (ADS)

    Culha, Mustafa; Karatas, Omer F.; Aydin, Omer; Kahraman, Mehmet; Keseroğlu, Kemal; Sayin, Ismail; Bayrak, Omer F.

    2009-02-01

    The development of an assay for the detection of gene mutations has been attempted based on surface-enhanced Raman scattering (SERS). Using multiplexing property and high sensitivity of SERS technique, the detection of all mutation possibilities on one given spot is achievable. To test the feasibility of approach, SNPs and other types of mutations such as insertion and deletion are investigated. The PCR amplified and isolated genomic DNA without PCR amplification is immobilized on poly-L/D-lysine coated glass surface after denaturing with heating. The SERS probes are prepared by simultaneous attachment of oligonucleotides complementary to the target mutation regions and Raman active dyes to 13 nm gold nanoparticles (GNPs). After the hybridization of SERS probes on the poly-L/D-lysine surfaces, it was stained with silver colloidal nanoparticles for further enhancement of Raman scattering. In the second approach, Raman active dyes are chemically attached on gold nanoparticles and a thin layer of silver film is deposited on top of it to prepare core-shell nanoparticles. The complementary oligonucleotides to the target regions of the gene are chemically attached to silver surfaces of the nanoparticles. The promising results indicate that it is possible to detect certain mutation types without PCR amplification using the approach.

  7. Design and development of PCR-free highly sensitive electrochemical assay for detection of telomerase activity using Nano-based (liposomal) signal amplification platform.

    PubMed

    Alizadeh-Ghodsi, Mohammadreza; Zavari-Nematabad, Ali; Hamishehkar, Hamed; Akbarzadeh, Abolfazl; Mahmoudi-Badiki, Tohid; Zarghami, Faraz; Pourhassan Moghaddam, Mohammad; Alipour, Esmaeel; Zarghami, Nosratollah

    2016-06-15

    Telomerase, which has been detected in almost all kinds of cancer tissues, is considered as an important tumor marker for early cancer diagnostics. In the present study, an electrochemical method based on liposomal signal amplification platform is proposed for simple, PCR-free, and highly sensitive detection of human telomerase activity, extracted from A549 cells. In this strategy, telomerase reaction products, which immobilized on streptavidin-coated microplate, hybridized with biotinylated capture probes. Then, dopamine-loaded biotinylated liposomes are attached through streptavidin to biotinylated capture probes. Finally, liposomes are ruptured by methanol and the released-dopamine is subsequently measured using differential pulse voltammetry technique by multi-walled carbon nanotubes modified glassy carbon electrode. Using this strategy, the telomerase activity extracted from 10 cultured cancer cells could be detected. Therefore, this approach affords high sensitivity for telomerase activity detection and it can be regarded as an alternative to telomeric repeat amplification protocol assay, having the advantages of simplicity and less assay time. Copyright © 2016 Elsevier B.V. All rights reserved.

  8. PCR-free and label-free fluorescent detection of telomerase activity at single-cell level based on triple amplification.

    PubMed

    Gao, Yanfang; Xu, Jing; Li, Baoxin; Jin, Yan

    2016-07-15

    As a universal biomarker for cancer diagnostics and cancer therapeutics, telomerase has attracted extensive attention concerning its detection and discovery of its inhibitors. Herein, we developed a PCR-free and label-free fluorescent strategy for facile, reliable and highly sensitive assay of human telomerase activity from crude cancer cell extracts. A G-quadruplex-selective fluorescent dye, N-methyl mesoporphyrin IX (NMM), was utilized as signal probe. Two hairpin probes with hidden G-quadruplex strand in their stem were designed as assembly components of strand displacement reaction (SDR). In this strategy, one telomerase elongation product contains several hexamer repeats which can hybridize with numerous assistant DNA to release a lot of trigger DNA (T-DNA) of SDR for achieving first step amplification. Then, strand displacement reaction led to the formation of G-quadruplex at the both end of two hairpin DNA probes for realizing second step amplification. Finally, the re-released T-DNA initiated another cycle of SDR, resulting in a significant increase in the fluorescence intensity of NMM. By taking advantage of triple signal amplification, the telomerase activity in the HeLa extracts equivalent to 1-3000 cells was detected in homogeneous solution. Telomerase activities of different cell lines, including cancer cells and normal cell, were also successfully evaluated. Meanwhile, the inhibition effect of 3'-azido-3'-deoxythymidine (AZT) was also investigated. Therefore, it offers a simple and reliable method for detecting telomerase activity at single-cell level without complex pre-modification of probe and enzyme auxiliary signal amplification, which has the merits of simplicity, rapid response, low cost and high reliability.

  9. Mitochondrial capture enriches mito-DNA 100 fold, enabling PCR-free mitogenomics biodiversity analysis.

    PubMed

    Liu, Shanlin; Wang, Xin; Xie, Lin; Tan, Meihua; Li, Zhenyu; Su, Xu; Zhang, Hao; Misof, Bernhard; Kjer, Karl M; Tang, Min; Niehuis, Oliver; Jiang, Hui; Zhou, Xin

    2016-03-01

    Biodiversity analyses based on next-generation sequencing (NGS) platforms have developed by leaps and bounds in recent years. A PCR-free strategy, which can alleviate taxonomic bias, was considered as a promising approach to delivering reliable species compositions of targeted environments. The major impediment of such a method is the lack of appropriate mitochondrial DNA enrichment ways. Because mitochondrial genomes (mitogenomes) make up only a small proportion of total DNA, PCR-free methods will inevitably result in a huge excess of data (>99%). Furthermore, the massive volume of sequence data is highly demanding on computing resources. Here, we present a mitogenome enrichment pipeline via a gene capture chip that was designed by virtue of the mitogenome sequences of the 1000 Insect Transcriptome Evolution project (1KITE, www.1kite.org). A mock sample containing 49 species was used to evaluate the efficiency of the mitogenome capture method. We demonstrate that the proportion of mitochondrial DNA can be increased by approximately 100-fold (from the original 0.47% to 42.52%). Variation in phylogenetic distances of target taxa to the probe set could in principle result in bias in abundance. However, the frequencies of input taxa were largely maintained after capture (R(2) = 0.81). We suggest that our mitogenome capture approach coupled with PCR-free shotgun sequencing could provide ecological researchers an efficient NGS method to deliver reliable biodiversity assessment. © 2015 The Authors. Molecular Ecology Resources Published by John Wiley & Sons Ltd.

  10. PCR-free digital minisatellite tandem repeat genotyping.

    PubMed

    Chen, Yuchao; Seo, Tae Seok

    2011-06-01

    We demonstrated a proof-of-concept for novel minisatellite tandem repeat typing, called PCR-free digital VNTR (variable number tandem repeat) typing, which is composed of three steps: a ligation reaction instead of PCR thermal cycling, magnetic bead-based solid-phase capture for purification, and an elongated sample stacking microcapillary electrophoresis (μCE) for sensitive digital coding of repeat number. We designed a 16-bp fluorescently labeled ligation probe which is complementary to a repeat unit of a biotinylated synthetic template mimicking the human D1S80 VNTR locus and is randomly hybridized with the minisatellite tandem repeats. A quick isothermal ligation reaction was followed to link the adjacent ligation probes on the DNA templates, and then the ligated products were purified by streptavidin-coated magnetic beads. After a denaturing step, a large amount of ligated products whose size difference was equivalent to the repeat unit were released and recovered. Through the elongated sample stacking μCE separation on a microdevice, the fluorescence signal of the ligated products was generated in the electropherogram and the peak number was directly counted which was exactly matched with the repeat number of VNTR locus. We could successfully identify the minisatellite tandem repeat number with only 5 fmol of DNA template in 30 min.

  11. A label-free, PCR-free and signal-on electrochemical DNA biosensor for Leishmania major based on gold nanoleaves.

    PubMed

    Moradi, M; Sattarahmady, N; Rahi, A; Hatam, G R; Sorkhabadi, S M Rezayat; Heli, H

    2016-12-01

    Detection of leishmaniasis is important in clinical diagnoses. In the present study, identification of Leishmania parasites was performed by a label-free, PCR-free and signal-on ultrasensitive electrochemical DNA biosensor. Gold nanoleaves were firstly electrodeposited by an electrodeposition method using spermidine as a shape directing agent. The biosensor was fabricated by immobilization of a Leishmania major specific DNA probe onto gold nanoleaves, and methylene blue was employed as a marker. Hybridization of the complementary single stranded DNA sequence with the biosensor under the selected conditions was then investigated. The biosensor could detect a synthetic DNA target in a range of 1.0×10(-10) to 1.0×10(-19)molL(-1) with a limit of detection of 1.8×10(-20)molL(-1), and genomic DNA in a range of 0.5-20ngμL(-1) with a limit of detection of 0.07ngμL(-1). The biosensor could distinguish Leishmania major from a non-complementary-sequence oligonucleotide and the tropica species with a high selectivity. The biosensor was applicable to detect Leishmania major in patient samples.

  12. Methods of Melanoma Detection.

    PubMed

    Leachman, Sancy A; Cassidy, Pamela B; Chen, Suephy C; Curiel, Clara; Geller, Alan; Gareau, Daniel; Pellacani, Giovanni; Grichnik, James M; Malvehy, Josep; North, Jeffrey; Jacques, Steven L; Petrie, Tracy; Puig, Susana; Swetter, Susan M; Tofte, Susan; Weinstock, Martin A

    2016-01-01

    Detection and removal of melanoma, before it has metastasized, dramatically improves prognosis and survival. The purpose of this chapter is to (1) summarize current methods of melanoma detection and (2) review state-of-the-art detection methods and technologies that have the potential to reduce melanoma mortality. Current strategies for the detection of melanoma range from population-based educational campaigns and screening to the use of algorithm-driven imaging technologies and performance of assays that identify markers of transformation. This chapter will begin by describing state-of-the-art methods for educating and increasing awareness of at-risk individuals and for performing comprehensive screening examinations. Standard and advanced photographic methods designed to improve reliability and reproducibility of the clinical examination will also be reviewed. Devices that magnify and/or enhance malignant features of individual melanocytic lesions (and algorithms that are available to interpret the results obtained from these devices) will be compared and contrasted. In vivo confocal microscopy and other cellular-level in vivo technologies will be compared to traditional tissue biopsy, and the role of a noninvasive "optical biopsy" in the clinical setting will be discussed. Finally, cellular and molecular methods that have been applied to the diagnosis of melanoma, such as comparative genomic hybridization (CGH), fluorescent in situ hybridization (FISH), and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR), will be discussed.

  13. Methods of Endotoxin Detection.

    PubMed

    Su, Wenqiong; Ding, Xianting

    2015-08-01

    Endotoxin, present in the outer membrane of all gram-negative bacteria, can pose serious risks to human health, from irreversible shock to death. Therefore, it is essential to develop sensitive, accurate, and rapid methods for its detection. The rabbit pyrogen test is the first standard technique for endotoxin detection and, nowadays, has been replaced by the Limulus Amoebocyte Lysate test, which is the most popular detection technique for endotoxin. With in-depth understanding of endotoxin, biosensors based on endotoxin-sensing components are promising alternatives to pursue in developing low-cost, easy-operation, and fast-response endotoxin detection techniques. This article summarizes the recent advances of endotoxin detection methods with a particular emphasis on optical and electrochemical biosensors based on various sensing elements ranging from nature biomolecules to artificial materials. As the research and technological revolution continues, the highly integrated and miniaturized commercial devices for sensitively and reliably detecting endotoxin will provide a wide range of applications in people's daily life.

  14. Error detection method

    DOEpatents

    Olson, Eric J.

    2013-06-11

    An apparatus, program product, and method that run an algorithm on a hardware based processor, generate a hardware error as a result of running the algorithm, generate an algorithm output for the algorithm, compare the algorithm output to another output for the algorithm, and detect the hardware error from the comparison. The algorithm is designed to cause the hardware based processor to heat to a degree that increases the likelihood of hardware errors to manifest, and the hardware error is observable in the algorithm output. As such, electronic components may be sufficiently heated and/or sufficiently stressed to create better conditions for generating hardware errors, and the output of the algorithm may be compared at the end of the run to detect a hardware error that occurred anywhere during the run that may otherwise not be detected by traditional methodologies (e.g., due to cooling, insufficient heat and/or stress, etc.).

  15. Method for detecting biomolecules

    SciTech Connect

    Huo, Qisheng; Liu, Jun

    2008-08-12

    A method for detecting and measuring the concentration of biomolecules in solution, utilizing a conducting electrode in contact with a solution containing target biomolecules, with a film with controllable pore size distribution characteristics applied to at least one surface of the conducting electrode. The film is functionalized with probe molecules that chemically interact with the target biomolecules at the film surface, blocking indicator molecules present in solution from diffusing from the solution to the electrode, thereby changing the electrochemical response of the electrode

  16. Nucleic acid detection methods

    DOEpatents

    Smith, C.L.; Yaar, R.; Szafranski, P.; Cantor, C.R.

    1998-05-19

    The invention relates to methods for rapidly determining the sequence and/or length a target sequence. The target sequence may be a series of known or unknown repeat sequences which are hybridized to an array of probes. The hybridized array is digested with a single-strand nuclease and free 3{prime}-hydroxyl groups extended with a nucleic acid polymerase. Nuclease cleaved heteroduplexes can be easily distinguish from nuclease uncleaved heteroduplexes by differential labeling. Probes and target can be differentially labeled with detectable labels. Matched target can be detected by cleaving resulting loops from the hybridized target and creating free 3-hydroxyl groups. These groups are recognized and extended by polymerases added into the reaction system which also adds or releases one label into solution. Analysis of the resulting products using either solid phase or solution. These methods can be used to detect characteristic nucleic acid sequences, to determine target sequence and to screen for genetic defects and disorders. Assays can be conducted on solid surfaces allowing for multiple reactions to be conducted in parallel and, if desired, automated. 18 figs.

  17. Nucleic Acid Detection Methods

    DOEpatents

    Smith, Cassandra L.; Yaar, Ron; Szafranski, Przemyslaw; Cantor, Charles R.

    1998-05-19

    The invention relates to methods for rapidly determining the sequence and/or length a target sequence. The target sequence may be a series of known or unknown repeat sequences which are hybridized to an array of probes. The hybridized array is digested with a single-strand nuclease and free 3'-hydroxyl groups extended with a nucleic acid polymerase. Nuclease cleaved heteroduplexes can be easily distinguish from nuclease uncleaved heteroduplexes by differential labeling. Probes and target can be differentially labeled with detectable labels. Matched target can be detected by cleaving resulting loops from the hybridized target and creating free 3-hydroxyl groups. These groups are recognized and extended by polymerases added into the reaction system which also adds or releases one label into solution. Analysis of the resulting products using either solid phase or solution. These methods can be used to detect characteristic nucleic acid sequences, to determine target sequence and to screen for genetic defects and disorders. Assays can be conducted on solid surfaces allowing for multiple reactions to be conducted in parallel and, if desired, automated.

  18. Waveguide disturbance detection method

    DOEpatents

    Korneev, Valeri A.; Nihei, Kurt T.; Myer, Larry R.

    2000-01-01

    A method for detection of a disturbance in a waveguide comprising transmitting a wavefield having symmetric and antisymmetric components from a horizontally and/or vertically polarized source and/or pressure source disposed symmetrically with respect to the longitudinal central axis of the waveguide at one end of the waveguide, recording the horizontal and/or vertical component or a pressure of the wavefield with a vertical array of receivers disposed at the opposite end of the waveguide, separating the wavenumber transform of the wavefield into the symmetric and antisymmetric components, integrating the symmetric and antisymmetric components over a broad frequency range, and comparing the magnitude of the symmetric components and the antisymmetric components to an expected magnitude for the symmetric components and the antisymmetric components for a waveguide of uniform thickness and properties thereby determining whether or not a disturbance is present inside the waveguide.

  19. Methods of DNA methylation detection

    NASA Technical Reports Server (NTRS)

    Maki, Wusi Chen (Inventor); Filanoski, Brian John (Inventor); Mishra, Nirankar (Inventor); Rastogi, Shiva (Inventor)

    2010-01-01

    The present invention provides for methods of DNA methylation detection. The present invention provides for methods of generating and detecting specific electronic signals that report the methylation status of targeted DNA molecules in biological samples.Two methods are described, direct and indirect detection of methylated DNA molecules in a nano transistor based device. In the direct detection, methylated target DNA molecules are captured on the sensing surface resulting in changes in the electrical properties of a nano transistor. These changes generate detectable electronic signals. In the indirect detection, antibody-DNA conjugates are used to identify methylated DNA molecules. RNA signal molecules are generated through an in vitro transcription process. These RNA molecules are captured on the sensing surface change the electrical properties of nano transistor thereby generating detectable electronic signals.

  20. Exoplanet Detection by Astrometric Method

    NASA Astrophysics Data System (ADS)

    Xu, Wei-wei; Liao, Xin-hao; Zhou, Yong-hong; Xu, Xue-qing

    2017-07-01

    As we know, the exoplanets are mostly detected by the methods of radial velocity and transit, up to now only one is found by the astrometric method. As the data of the gaia will be soon released, astrometry will gradually become one of the most important methods for detecting exoplanets. Based on the sequence of star positions obtained by the astrometric method, the solution of the equations of dynamical conditions involving the calculations of planet's mass and orbital parameters is discussed in this paper. Due to the deficiency of the available theory (orbital element method), a new method (coordinate velocity method) is put forward. The differential correction formulae of the two methods, as well as the necessary simulation calculations are presented. In addition, the method established in this paper can be applied to the multi-planet system easily.

  1. Method for detecting an element

    DOEpatents

    Blackwood, Larry G.; Reber, Edward L.; Rohde, Kenneth W.

    2007-02-06

    A method for detecting an element is disclosed and which includes the steps of providing a gamma-ray spectrum which depicts, at least in part, a test region having boundaries, and which has a small amount of the element to be detected; providing a calculation which detects the small amount of the element to be detected; and providing a moving window and performing the calculation within the moving window, and over a range of possible window boundaries within the test region to determine the location of the optimal test region within the gamma-ray spectrum.

  2. Outlier detection method in GEEs.

    PubMed

    Pardo, María Del Carmen; Hobza, Tomáš

    2014-09-01

    The generalized estimating equations (GEEs) method has become quite useful in modeling correlated data. However, diagnostic tools to check that the selected final model fits the data as accurately as possible have not been explored intensively. In this paper, an outlier detection technique is developed based on the use of the "working" score test statistic to test an appropriate mean-shift model in the context of longitudinal studies based on GEEs. Through a simulation study it has been shown that this method correctly singled out the outlier when the data set had a known outlier. The method is applied to a set of data to illustrate the outlier detection procedure in GEEs.

  3. Method for detecting biological toxins

    SciTech Connect

    Ligler, F.S.; Campbell, J.R.

    1992-01-01

    Biological toxins are indirectly detected by using polymerase chain reaction to amplify unique nucleic acid sequences coding for the toxins or enzymes unique to toxin synthesis. Buffer, primers coding for the unique nucleic acid sequences and an amplifying enzyme are added to a sample suspected of containing the toxin. The mixture is then cycled thermally to exponentially amplify any of these unique nucleic acid sequences present in the sample. The amplified sequences can be detected by various means, including fluorescence. Detection of the amplified sequences is indicative of the presence of toxin in the original sample. By using more than one set of labeled primers, the method can be used to simultaneously detect several toxins in a sample.

  4. Method for detecting toxic gases

    DOEpatents

    Stetter, J.R.; Zaromb, S.; Findlay, M.W. Jr.

    1991-10-08

    A method is disclosed which is capable of detecting low concentrations of a pollutant or other component in air or other gas. This method utilizes a combination of a heating filament having a catalytic surface of a noble metal for exposure to the gas and producing a derivative chemical product from the component. An electrochemical sensor responds to the derivative chemical product for providing a signal indicative of the product. At concentrations in the order of about 1-100 ppm of tetrachloroethylene, neither the heating filament nor the electrochemical sensor is individually capable of sensing the pollutant. In the combination, the heating filament converts the benzyl chloride to one or more derivative chemical products which may be detected by the electrochemical sensor. 6 figures.

  5. Survey of Anomaly Detection Methods

    SciTech Connect

    Ng, B

    2006-10-12

    This survey defines the problem of anomaly detection and provides an overview of existing methods. The methods are categorized into two general classes: generative and discriminative. A generative approach involves building a model that represents the joint distribution of the input features and the output labels of system behavior (e.g., normal or anomalous) then applies the model to formulate a decision rule for detecting anomalies. On the other hand, a discriminative approach aims directly to find the decision rule, with the smallest error rate, that distinguishes between normal and anomalous behavior. For each approach, we will give an overview of popular techniques and provide references to state-of-the-art applications.

  6. Tunnel Detection Using Seismic Methods

    NASA Astrophysics Data System (ADS)

    Miller, R.; Park, C. B.; Xia, J.; Ivanov, J.; Steeples, D. W.; Ryden, N.; Ballard, R. F.; Llopis, J. L.; Anderson, T. S.; Moran, M. L.; Ketcham, S. A.

    2006-05-01

    Surface seismic methods have shown great promise for use in detecting clandestine tunnels in areas where unauthorized movement beneath secure boundaries have been or are a matter of concern for authorities. Unauthorized infiltration beneath national borders and into or out of secure facilities is possible at many sites by tunneling. Developments in acquisition, processing, and analysis techniques using multi-channel seismic imaging have opened the door to a vast number of near-surface applications including anomaly detection and delineation, specifically tunnels. Body waves have great potential based on modeling and very preliminary empirical studies trying to capitalize on diffracted energy. A primary limitation of all seismic energy is the natural attenuation of high-frequency energy by earth materials and the difficulty in transmitting a high- amplitude source pulse with a broad spectrum above 500 Hz into the earth. Surface waves have shown great potential since the development of multi-channel analysis methods (e.g., MASW). Both shear-wave velocity and backscatter energy from surface waves have been shown through modeling and empirical studies to have great promise in detecting the presence of anomalies, such as tunnels. Success in developing and evaluating various seismic approaches for detecting tunnels relies on investigations at known tunnel locations, in a variety of geologic settings, employing a wide range of seismic methods, and targeting a range of uniquely different tunnel geometries, characteristics, and host lithologies. Body-wave research at the Moffat tunnels in Winter Park, Colorado, provided well-defined diffraction-looking events that correlated with the subsurface location of the tunnel complex. Natural voids related to karst have been studied in Kansas, Oklahoma, Alabama, and Florida using shear-wave velocity imaging techniques based on the MASW approach. Manmade tunnels, culverts, and crawl spaces have been the target of multi-modal analysis

  7. Method for detecting toxic gases

    SciTech Connect

    Stetter, Joseph R.; Zaromb, Solomon; Findlay, Jr., Melvin W.

    1991-01-01

    A method capable of detecting low concentrations of a pollutant or other component in air or other gas, utilizing a combination of a heating filament having a catalytic surface of a noble metal for exposure to the gas and producing a derivative chemical product from the component, and an electrochemical sensor responsive to the derivative chemical product for providing a signal indicative of the product. At concentrations in the order of about 1-100 ppm of tetrachloroethylene, neither the heating filament nor the electrochemical sensor is individually capable of sensing the pollutant. In the combination, the heating filament converts the benzyl chloride to one or more derivative chemical products which may be detected by the electrochemical sensor.

  8. Bacteria detection instrument and method

    NASA Technical Reports Server (NTRS)

    Renner, W.; Fealey, R. D. (Inventor)

    1972-01-01

    A method and apparatus for screening a sample fluid for bacterial presence are disclosed wherein the fluid sample is mixed with culture media of sufficient quantity to permit bacterial growth in order to obtain a test solution. The concentration of oxygen dissolved in the test solution is then monitored using the potential difference between a reference electrode and a noble metal electrode which are in contact with the test solution. The change in oxygen concentration which occurs during a period of time as indicated by the electrode potential difference is compared with a detection criterion which exceeds the change which would occur absent bacteria.

  9. Explosives detection system and method

    DOEpatents

    Reber, Edward L.; Jewell, James K.; Rohde, Kenneth W.; Seabury, Edward H.; Blackwood, Larry G.; Edwards, Andrew J.; Derr, Kurt W.

    2007-12-11

    A method of detecting explosives in a vehicle includes providing a first rack on one side of the vehicle, the rack including a neutron generator and a plurality of gamma ray detectors; providing a second rack on another side of the vehicle, the second rack including a neutron generator and a plurality of gamma ray detectors; providing a control system, remote from the first and second racks, coupled to the neutron generators and gamma ray detectors; using the control system, causing the neutron generators to generate neutrons; and performing gamma ray spectroscopy on spectra read by the gamma ray detectors to look for a signature indicative of presence of an explosive. Various apparatus and other methods are also provided.

  10. Immunofluorescence detection methods using microspheres

    NASA Astrophysics Data System (ADS)

    Szurdoki, Ferenc; Michael, Karri L.; Agrawal, Divya; Taylor, Laura C.; Schultz, Sandra L.; Walt, David R.

    1999-01-01

    Microsphere-based immunoassays were devised for compounds of agricultural and biomedical interest (e.g., digoxin, theophylline, and zearalenone). Commercially available microspheres with surface functional groups for chemical derivatization were used as solid carriers. After immobilizing the target substances, the surface of the haptenized microspheres was blocked by a protein to reduce aspecific binding. Competitive immunoassays were performed using the functionalized microspheres and antibodies labeled with horseradish peroxidase. Immunofluorescence signal amplification was achieved by enzyme-catalyzed reporter deposition (CARD). An epifluorescence microscope, a CCD camera interfaced with a computer, and microscopy image analysis software were employed for quantitative detection of fluorescent light emitted from individual microspheres. Integration of several such immunoassays and application of an optical encoding method enabled multianalyte determination. These immunoassays can also be utilized in an immunosensor array format. This immunoarray format could facilitate miniaturization and automation of multianalyte immunoassays.

  11. Development of a PCR free, fieldable, rapid, accurate, and sensitive bio-electronic DNA biosensor

    NASA Astrophysics Data System (ADS)

    Hill, Doyle; Chafin, David; Greco, Roberta; Jafri, Samina; Murante, Richard; Noonan, John; Pham, An; Seabridge, Scott; Tannous, Vera; VanDerMeid, Karl; Wang, Daguang; Wescott, Nate; McFarlane, Kristin; Shah, Sanjiv

    2005-05-01

    The objective of this study was to demonstrate proof of concept for the Integrated Nano-Technologies BioDetect Bacillus anthracis electronic DNA sensor. B. anthracis Ames strain DNA was successfully detected by the formation of DNA bridges on the sensor. The bridges were coated with metal, resulting in a significant drop in electrical resistance. In this small test, at a relatively high DNA concentration, the overall accuracy of the sensor was 90.7%. The technology shows significant promise for future development as a bio-agent detection system.

  12. Particle detection systems and methods

    DOEpatents

    Morris, Christopher L.; Makela, Mark F.

    2010-05-11

    Techniques, apparatus and systems for detecting particles such as muons and neutrons. In one implementation, a particle detection system employs a plurality of drift cells, which can be for example sealed gas-filled drift tubes, arranged on sides of a volume to be scanned to track incoming and outgoing charged particles, such as cosmic ray-produced muons. The drift cells can include a neutron sensitive medium to enable concurrent counting of neutrons. The system can selectively detect devices or materials, such as iron, lead, gold, uranium, plutonium, and/or tungsten, occupying the volume from multiple scattering of the charged particles passing through the volume and can concurrently detect any unshielded neutron sources occupying the volume from neutrons emitted therefrom. If necessary, the drift cells can be used to also detect gamma rays. The system can be employed to inspect occupied vehicles at border crossings for nuclear threat objects.

  13. Method For Detecting Biological Agents

    DOEpatents

    Chen, Liaohai; McBranch, Duncan W.; Wang, Hsing-Lin; Whitten, David G.

    2005-12-27

    A sensor is provided including a polymer capable of having an alterable measurable property from the group of luminescence and electrical conductivity, the polymer having an intermediate combination of a recognition element, a tethering element and a property-altering element bound thereto and capable of altering the measurable property, the intermediate combination adapted for subsequent separation from the polymer upon exposure to an agent having an affinity for binding to the recognition element whereupon the separation of the intermediate combination from the polymer results in a detectable change in the alterable measurable property, and, detecting said detectable change in the alterable measurable property.

  14. Cancer Detection and Diagnosis Methods - Annual Plan

    Cancer.gov

    Early cancer detection is a proven life-saving strategy. Learn about the research opportunities NCI supports, including liquid biopsies and other less-invasive methods, for detecting early cancers and precancerous growths.

  15. Method of detecting sulfur dioxide

    DOEpatents

    Spicer, Leonard D.; Bennett, Dennis W.; Davis, Jon F.

    1985-01-01

    (CH.sub.3).sub.3 SiNSO is produced by the reaction of ((CH.sub.3).sub.3 Si).sub.2 NH with SO.sub.2. Also produced in the reaction are ((CH.sub.3).sub.3 Si).sub.2 O and a new solid compound [NH.sub.4 ][(CH.sub.3).sub.3 SiOSO.sub.2 ]. Both (CH.sub.3).sub.3 SiNSO and [NH.sub.4 ][(CH.sub.3).sub.3 SiOSO.sub.2 ] have fluorescent properties. The reaction of the subject invention is used in a method of measuring the concentration of SO.sub.2 pollutants in gases. By the method, a sample of gas is bubbled through a solution of ((CH.sub.3).sub.3 Si).sub.2 NH, whereby any SO.sub.2 present in the gas will react to produce the two fluorescent products. The measured fluorescence of these products can then be used to calculate the concentration of SO.sub.2 in the original gas sample. The solid product [NH.sub.4][(CH.sub.3).sub.3 SiOSO.sub.2 ] may be used as a standard in solid state NMR spectroscopy.

  16. Robust statistical methods for automated outlier detection

    NASA Technical Reports Server (NTRS)

    Jee, J. R.

    1987-01-01

    The computational challenge of automating outlier, or blunder point, detection in radio metric data requires the use of nonstandard statistical methods because the outliers have a deleterious effect on standard least squares methods. The particular nonstandard methods most applicable to the task are the robust statistical techniques that have undergone intense development since the 1960s. These new methods are by design more resistant to the effects of outliers than standard methods. Because the topic may be unfamiliar, a brief introduction to the philosophy and methods of robust statistics is presented. Then the application of these methods to the automated outlier detection problem is detailed for some specific examples encountered in practice.

  17. Biological methods for marine toxin detection.

    PubMed

    Vilariño, Natalia; Louzao, M Carmen; Vieytes, Mercedes R; Botana, Luis M

    2010-07-01

    The presence of marine toxins in seafood poses a health risk to human consumers which has prompted the regulation of the maximum content of marine toxins in seafood in the legislations of many countries. Most marine toxin groups are detected by animal bioassays worldwide. Although this method has well known ethical and technical drawbacks, it is the official detection method for all regulated phycotoxins except domoic acid. Much effort by the scientific and regulatory communities has been focused on the development of alternative techniques that enable the substitution or reduction of bioassays; some of these have recently been included in the official detection method list. During the last two decades several biological methods including use of biosensors have been adapted for detection of marine toxins. The main advances in marine toxin detection using this kind of technique are reviewed. Biological methods offer interesting possibilities for reduction of the number of biosassays and a very promising future of new developments.

  18. Method for detecting coliform organisms

    NASA Technical Reports Server (NTRS)

    Nishioka, K.; Nibley, D. A.; Jeffers, E. L.; Brooks, R. L. (Inventor)

    1983-01-01

    A method and apparatus are disclosed for determining the concentration of coliform bacteria in a sample. The sample containing the coliform bacteria is cultured in a liquid growth medium. The cultured bacteria produce hydrogen and the hydrogen is vented to a second cell containing a buffer solution in which the hydrogen dissolves. By measuring the potential change in the buffer solution caused by the hydrogen, as a function of time, the initial concentration of bacteria in the sample is determined. Alternatively, the potential change in the buffer solution can be compared with the potential change in the liquid growth medium to verify that the potential change in the liquid growth medium is produced primarily by the hydrogen gas produced by the coliform bacteria.

  19. Improved moving object detection and tracking method

    NASA Astrophysics Data System (ADS)

    Li, Zhanli; Yang, Fang; Li, Hong-an

    2016-07-01

    At present, the detection and tracking for video moving object have been used in many fields. Aimed at the limitation of the traditional adjacent frame difference method, this paper presented the three-frame difference method to detect objects. For moving object tracking, this paper proposed a method combining Kalman filter and Mean-Shift, and used the prediction function of Kalman filter to overcome the defect of Mean-Shift in selecting the initial position of the candidate object. Experimental results showed that the detection and tracking method proposed in this paper are simple, precise, and perform a good result.

  20. Spectral analysis method for detecting an element

    DOEpatents

    Blackwood, Larry G [Idaho Falls, ID; Edwards, Andrew J [Idaho Falls, ID; Jewell, James K [Idaho Falls, ID; Reber, Edward L [Idaho Falls, ID; Seabury, Edward H [Idaho Falls, ID

    2008-02-12

    A method for detecting an element is described and which includes the steps of providing a gamma-ray spectrum which has a region of interest which corresponds with a small amount of an element to be detected; providing nonparametric assumptions about a shape of the gamma-ray spectrum in the region of interest, and which would indicate the presence of the element to be detected; and applying a statistical test to the shape of the gamma-ray spectrum based upon the nonparametric assumptions to detect the small amount of the element to be detected.

  1. Bacillus spore inactivation methods affect detection assays.

    PubMed

    Dang, J L; Heroux, K; Kearney, J; Arasteh, A; Gostomski, M; Emanuel, P A

    2001-08-01

    Detection of biological weapons is a primary concern in force protection, treaty verification, and safeguarding civilian populations against domestic terrorism. One great concern is the detection of Bacillus anthracis, the causative agent of anthrax. Assays for detection in the laboratory often employ inactivated preparations of spores or nonpathogenic simulants. This study uses several common biodetection platforms to detect B. anthracis spores that have been inactivated by two methods and compares those data to detection of spores that have not been inactivated. The data demonstrate that inactivation methods can affect the sensitivity of nucleic acid- and antibody-based assays for the detection of B. anthracis spores. These effects should be taken into consideration when comparing laboratory results to data collected and assayed during field deployment.

  2. Bacillus Spore Inactivation Methods Affect Detection Assays

    PubMed Central

    Dang, Jessica L.; Heroux, Karen; Kearney, John; Arasteh, Ameneh; Gostomski, Mark; Emanuel, Peter A.

    2001-01-01

    Detection of biological weapons is a primary concern in force protection, treaty verification, and safeguarding civilian populations against domestic terrorism. One great concern is the detection of Bacillus anthracis, the causative agent of anthrax. Assays for detection in the laboratory often employ inactivated preparations of spores or nonpathogenic simulants. This study uses several common biodetection platforms to detect B. anthracis spores that have been inactivated by two methods and compares those data to detection of spores that have not been inactivated. The data demonstrate that inactivation methods can affect the sensitivity of nucleic acid- and antibody-based assays for the detection of B. anthracis spores. These effects should be taken into consideration when comparing laboratory results to data collected and assayed during field deployment. PMID:11472945

  3. GMDD: a database of GMO detection methods

    PubMed Central

    Dong, Wei; Yang, Litao; Shen, Kailin; Kim, Banghyun; Kleter, Gijs A; Marvin, Hans JP; Guo, Rong; Liang, Wanqi; Zhang, Dabing

    2008-01-01

    Background Since more than one hundred events of genetically modified organisms (GMOs) have been developed and approved for commercialization in global area, the GMO analysis methods are essential for the enforcement of GMO labelling regulations. Protein and nucleic acid-based detection techniques have been developed and utilized for GMOs identification and quantification. However, the information for harmonization and standardization of GMO analysis methods at global level is needed. Results GMO Detection method Database (GMDD) has collected almost all the previous developed and reported GMOs detection methods, which have been grouped by different strategies (screen-, gene-, construct-, and event-specific), and also provide a user-friendly search service of the detection methods by GMO event name, exogenous gene, or protein information, etc. In this database, users can obtain the sequences of exogenous integration, which will facilitate PCR primers and probes design. Also the information on endogenous genes, certified reference materials, reference molecules, and the validation status of developed methods is included in this database. Furthermore, registered users can also submit new detection methods and sequences to this database, and the newly submitted information will be released soon after being checked. Conclusion GMDD contains comprehensive information of GMO detection methods. The database will make the GMOs analysis much easier. PMID:18522755

  4. GMDD: a database of GMO detection methods.

    PubMed

    Dong, Wei; Yang, Litao; Shen, Kailin; Kim, Banghyun; Kleter, Gijs A; Marvin, Hans J P; Guo, Rong; Liang, Wanqi; Zhang, Dabing

    2008-06-04

    Since more than one hundred events of genetically modified organisms (GMOs) have been developed and approved for commercialization in global area, the GMO analysis methods are essential for the enforcement of GMO labelling regulations. Protein and nucleic acid-based detection techniques have been developed and utilized for GMOs identification and quantification. However, the information for harmonization and standardization of GMO analysis methods at global level is needed. GMO Detection method Database (GMDD) has collected almost all the previous developed and reported GMOs detection methods, which have been grouped by different strategies (screen-, gene-, construct-, and event-specific), and also provide a user-friendly search service of the detection methods by GMO event name, exogenous gene, or protein information, etc. In this database, users can obtain the sequences of exogenous integration, which will facilitate PCR primers and probes design. Also the information on endogenous genes, certified reference materials, reference molecules, and the validation status of developed methods is included in this database. Furthermore, registered users can also submit new detection methods and sequences to this database, and the newly submitted information will be released soon after being checked. GMDD contains comprehensive information of GMO detection methods. The database will make the GMOs analysis much easier.

  5. CURRENT METHODS FOR DETECTION OF CRYPTOSPORIDIUM SPECIES

    EPA Science Inventory

    Current methods for detecting protozoa in water produce results that are highly variable. It is difficult to determine if the methods themselves, or the procedures for testing these methods, are the source of the variability. If testing procedures are responsible for high varia...

  6. CURRENT METHODS FOR DETECTION OF CRYPTOSPORIDIUM SPECIES

    EPA Science Inventory

    Current methods for detecting protozoa in water produce results that are highly variable. It is difficult to determine if the methods themselves, or the procedures for testing these methods, are the source of the variability. If testing procedures are responsible for high varia...

  7. An Iterative Item Bias Detection Method.

    ERIC Educational Resources Information Center

    Van Der Flier, Henk; And Others

    1984-01-01

    Two strategies for assessing item bias are discussed: methods comparing item difficulties unconditional on ability and methods comparing probabilities of response conditional on ability. Results suggest that the iterative logit method is an improvement on the noniterative one and is efficient in detecting biased and unbiased items. (Author/DWH)

  8. Detecting sulphate aerosol geoengineering with different methods

    DOE PAGES

    Lo, Y. T. Eunice; Charlton-Perez, Andrew J.; Lott, Fraser C.; ...

    2016-12-15

    Sulphate aerosol injection has been widely discussed as a possible way to engineer future climate. Monitoring it would require detecting its effects amidst internal variability and in the presence of other external forcings. Here, we investigate how the use of different detection methods and filtering techniques affects the detectability of sulphate aerosol geoengineering in annual-mean global-mean near-surface air temperature. This is done by assuming a future scenario that injects 5 Tg yr-1 of sulphur dioxide into the stratosphere and cross-comparing simulations from 5 climate models. 64% of the studied comparisons would require 25 years or more for detection when nomore » filter and the multi-variate method that has been extensively used for attributing climate change are used, while 66% of the same comparisons would require fewer than 10 years for detection using a trend-based filter. This then highlights the high sensitivity of sulphate aerosol geoengineering detectability to the choice of filter. With the same trend-based filter but a non-stationary method, 80% of the comparisons would require fewer than 10 years for detection. This does not imply sulphate aerosol geoengineering should be deployed, but suggests that both detection methods could be used for monitoring geoengineering in global, annual mean temperature should it be needed.« less

  9. Detecting sulphate aerosol geoengineering with different methods

    SciTech Connect

    Lo, Y. T. Eunice; Charlton-Perez, Andrew J.; Lott, Fraser C.; Highwood, Eleanor J.

    2016-12-15

    Sulphate aerosol injection has been widely discussed as a possible way to engineer future climate. Monitoring it would require detecting its effects amidst internal variability and in the presence of other external forcings. Here, we investigate how the use of different detection methods and filtering techniques affects the detectability of sulphate aerosol geoengineering in annual-mean global-mean near-surface air temperature. This is done by assuming a future scenario that injects 5 Tg yr-1 of sulphur dioxide into the stratosphere and cross-comparing simulations from 5 climate models. 64% of the studied comparisons would require 25 years or more for detection when no filter and the multi-variate method that has been extensively used for attributing climate change are used, while 66% of the same comparisons would require fewer than 10 years for detection using a trend-based filter. This then highlights the high sensitivity of sulphate aerosol geoengineering detectability to the choice of filter. With the same trend-based filter but a non-stationary method, 80% of the comparisons would require fewer than 10 years for detection. This does not imply sulphate aerosol geoengineering should be deployed, but suggests that both detection methods could be used for monitoring geoengineering in global, annual mean temperature should it be needed.

  10. Bioluminescent bioreporter integrated circuit detection methods

    DOEpatents

    Simpson, Michael L.; Paulus, Michael J.; Sayler, Gary S.; Applegate, Bruce M.; Ripp, Steven A.

    2005-06-14

    Disclosed are monolithic bioelectronic devices comprising a bioreporter and an OASIC. These bioluminescent bioreporter integrated circuit are useful in detecting substances such as pollutants, explosives, and heavy-metals residing in inhospitable areas such as groundwater, industrial process vessels, and battlefields. Also disclosed are methods and apparatus for detection of particular analytes, including ammonia and estrogen compounds.

  11. Detecting sulphate aerosol geoengineering with different methods

    PubMed Central

    Lo, Y. T. Eunice; Charlton-Perez, Andrew J.; Lott, Fraser C.; Highwood, Eleanor J.

    2016-01-01

    Sulphate aerosol injection has been widely discussed as a possible way to engineer future climate. Monitoring it would require detecting its effects amidst internal variability and in the presence of other external forcings. We investigate how the use of different detection methods and filtering techniques affects the detectability of sulphate aerosol geoengineering in annual-mean global-mean near-surface air temperature. This is done by assuming a future scenario that injects 5 Tg yr−1 of sulphur dioxide into the stratosphere and cross-comparing simulations from 5 climate models. 64% of the studied comparisons would require 25 years or more for detection when no filter and the multi-variate method that has been extensively used for attributing climate change are used, while 66% of the same comparisons would require fewer than 10 years for detection using a trend-based filter. This highlights the high sensitivity of sulphate aerosol geoengineering detectability to the choice of filter. With the same trend-based filter but a non-stationary method, 80% of the comparisons would require fewer than 10 years for detection. This does not imply sulphate aerosol geoengineering should be deployed, but suggests that both detection methods could be used for monitoring geoengineering in global, annual mean temperature should it be needed. PMID:27976697

  12. Detecting sulphate aerosol geoengineering with different methods

    NASA Astrophysics Data System (ADS)

    Lo, Y. T. Eunice; Charlton-Perez, Andrew J.; Lott, Fraser C.; Highwood, Eleanor J.

    2016-12-01

    Sulphate aerosol injection has been widely discussed as a possible way to engineer future climate. Monitoring it would require detecting its effects amidst internal variability and in the presence of other external forcings. We investigate how the use of different detection methods and filtering techniques affects the detectability of sulphate aerosol geoengineering in annual-mean global-mean near-surface air temperature. This is done by assuming a future scenario that injects 5 Tg yr-1 of sulphur dioxide into the stratosphere and cross-comparing simulations from 5 climate models. 64% of the studied comparisons would require 25 years or more for detection when no filter and the multi-variate method that has been extensively used for attributing climate change are used, while 66% of the same comparisons would require fewer than 10 years for detection using a trend-based filter. This highlights the high sensitivity of sulphate aerosol geoengineering detectability to the choice of filter. With the same trend-based filter but a non-stationary method, 80% of the comparisons would require fewer than 10 years for detection. This does not imply sulphate aerosol geoengineering should be deployed, but suggests that both detection methods could be used for monitoring geoengineering in global, annual mean temperature should it be needed.

  13. Detecting sulphate aerosol geoengineering with different methods.

    PubMed

    Lo, Y T Eunice; Charlton-Perez, Andrew J; Lott, Fraser C; Highwood, Eleanor J

    2016-12-15

    Sulphate aerosol injection has been widely discussed as a possible way to engineer future climate. Monitoring it would require detecting its effects amidst internal variability and in the presence of other external forcings. We investigate how the use of different detection methods and filtering techniques affects the detectability of sulphate aerosol geoengineering in annual-mean global-mean near-surface air temperature. This is done by assuming a future scenario that injects 5 Tg yr(-1) of sulphur dioxide into the stratosphere and cross-comparing simulations from 5 climate models. 64% of the studied comparisons would require 25 years or more for detection when no filter and the multi-variate method that has been extensively used for attributing climate change are used, while 66% of the same comparisons would require fewer than 10 years for detection using a trend-based filter. This highlights the high sensitivity of sulphate aerosol geoengineering detectability to the choice of filter. With the same trend-based filter but a non-stationary method, 80% of the comparisons would require fewer than 10 years for detection. This does not imply sulphate aerosol geoengineering should be deployed, but suggests that both detection methods could be used for monitoring geoengineering in global, annual mean temperature should it be needed.

  14. Methods for the detection of marine toxins

    SciTech Connect

    Wekell, M.M.; Manger, R.M.; Hadley, S.W.; Hungerford, J.M.

    1995-12-01

    Toxic materials have been dumped into the seas from waste streams and other pollutant sources such as runoff, etc. For protection of public health, it is essential that rapid, reliable and simple methods exist to detect marine toxins in seafoods. In addition, it is necessary to develop methods requiring a minimum of test material. Pure standards for many of the marine toxins are scarce. Reduced sample requirements extend the utility of detection methods in research and forensic applications as well. In the past, there was much reliance on the animal bioassay; however, this dependence hopefully will be reduced as newer instrumental techniques (chromatographic, mass spectrometric, electrophoretic), biochemical (immunochemical, receptor site assay), and cell bioassay methods are developed with a higher degree of precision and specificity. It is beneficial that a multiplicity of methods be available to detect marine toxins in seafoods. Each method has unique advantages and disadvantages.

  15. Colorimetric Method for Beryllium Surface Contamination Detection

    SciTech Connect

    MCWHORTER, CHRISTOPHER

    2004-03-11

    To address the need for real-time accurate total beryllium analyses, Savannah River Technology Center Analytical Development Section personnel evaluated and modified a colorimetric screening method developed at Los Alamos National Lab to measure beryllium on surfaces. This method was based on a color complex formed by beryllium and chromium azurol s . SRTC converted this visual method to a quantitative analysis method using spectrophotometric detection. The addition of a cationic surfactant (hexadecyltrimethylammonium bromide, CTAB) to the Be-CAS system shifted the complex absorbance away from the CAS absorbance and allowed for the detection. Assuming complete dissolution and a 10 mL rinse solution volume to remove the beryllium from the wipe, the detection limit was calculated comfortably below the free release limit. The spectrophotometric method was rugged and simple enough that it could be used as a field method.

  16. Automated Methods for Multiplexed Pathogen Detection

    SciTech Connect

    Straub, Tim M.; Dockendorff, Brian P.; Quinonez-Diaz, Maria D.; Valdez, Catherine O.; Shutthanandan, Janani I.; Tarasevich, Barbara J.; Grate, Jay W.; Bruckner-Lea, Cindy J.

    2005-09-01

    Detection of pathogenic microorganisms in environmental samples is a difficult process. Concentration of the organisms of interest also co-concentrates inhibitors of many end-point detection methods, notably, nucleic acid methods. In addition, sensitive, highly multiplexed pathogen detection continues to be problematic. The primary function of the BEADS (Biodetection Enabling Analyte Delivery System) platform is the automated concentration and purification of target analytes from interfering substances, often present in these samples, via a renewable surface column. In one version of BEADS, automated immunomagnetic separation (IMS) is used to separate cells from their samples. Captured cells are transferred to a flow-through thermal cycler where PCR, using labeled primers, is performed. PCR products are then detected by hybridization to a DNA suspension array. In another version of BEADS, cell lysis is performed, and community RNA is purified and directly labeled. Multiplexed detection is accomplished by direct hybridization of the RNA to a planar microarray. The integrated IMS/PCR version of BEADS can successfully purify and amplify 10 E. coli O157:H7 cells from river water samples. Multiplexed PCR assays for the simultaneous detection of E. coli O157:H7, Salmonella, and Shigella on bead suspension arrays was demonstrated for the detection of as few as 100 cells for each organism. Results for the RNA version of BEADS are also showing promising results. Automation yields highly purified RNA, suitable for multiplexed detection on microarrays, with microarray detection specificity equivalent to PCR. Both versions of the BEADS platform show great promise for automated pathogen detection from environmental samples. Highly multiplexed pathogen detection using PCR continues to be problematic, but may be required for trace detection in large volume samples. The RNA approach solves the issues of highly multiplexed PCR and provides ''live vs. dead'' capabilities. However

  17. Automated methods for multiplexed pathogen detection.

    PubMed

    Straub, Timothy M; Dockendorff, Brian P; Quiñonez-Díaz, Maria D; Valdez, Catherine O; Shutthanandan, Janani I; Tarasevich, Barbara J; Grate, Jay W; Bruckner-Lea, Cynthia J

    2005-09-01

    Detection of pathogenic microorganisms in environmental samples is a difficult process. Concentration of the organisms of interest also co-concentrates inhibitors of many end-point detection methods, notably, nucleic acid methods. In addition, sensitive, highly multiplexed pathogen detection continues to be problematic. The primary function of the BEADS (Biodetection Enabling Analyte Delivery System) platform is the automated concentration and purification of target analytes from interfering substances, often present in these samples, via a renewable surface column. In one version of BEADS, automated immunomagnetic separation (IMS) is used to separate cells from their samples. Captured cells are transferred to a flow-through thermal cycler where PCR, using labeled primers, is performed. PCR products are then detected by hybridization to a DNA suspension array. In another version of BEADS, cell lysis is performed, and community RNA is purified and directly labeled. Multiplexed detection is accomplished by direct hybridization of the RNA to a planar microarray. The integrated IMS/PCR version of BEADS can successfully purify and amplify 10 E. coli O157:H7 cells from river water samples. Multiplexed PCR assays for the simultaneous detection of E. coli O157:H7, Salmonella, and Shigella on bead suspension arrays was demonstrated for the detection of as few as 100 cells for each organism. Results for the RNA version of BEADS are also showing promising results. Automation yields highly purified RNA, suitable for multiplexed detection on microarrays, with microarray detection specificity equivalent to PCR. Both versions of the BEADS platform show great promise for automated pathogen detection from environmental samples. Highly multiplexed pathogen detection using PCR continues to be problematic, but may be required for trace detection in large volume samples. The RNA approach solves the issues of highly multiplexed PCR and provides "live vs. dead" capabilities. However

  18. Apparatus and methods for detecting chemical permeation

    DOEpatents

    Vo-Dinh, Tuan

    1994-01-01

    Apparatus and methods for detecting the permeation of hazardous or toxic chemicals through protective clothing are disclosed. The hazardous or toxic chemicals of interest do not possess the spectral characteristic of luminescence. The apparatus and methods utilize a spectrochemical modification technique to detect the luminescence quenching of an indicator compound which upon permeation of the chemical through the protective clothing, the indicator is exposed to the chemical, thus indicating chemical permeation.

  19. Radionuclide detection devices and associated methods

    DOEpatents

    Mann, Nicholas R [Rigby, ID; Lister, Tedd E [Idaho Falls, ID; Tranter, Troy J [Idaho Falls, ID

    2011-03-08

    Radionuclide detection devices comprise a fluid cell comprising a flow channel for a fluid stream. A radionuclide collector is positioned within the flow channel and configured to concentrate one or more radionuclides from the fluid stream onto at least a portion of the radionuclide collector. A scintillator for generating scintillation pulses responsive to an occurrence of a decay event is positioned proximate at least a portion of the radionuclide collector and adjacent to a detection system for detecting the scintillation pulses. Methods of selectively detecting a radionuclide are also provided.

  20. High sensitivity leak detection method and apparatus

    DOEpatents

    Myneni, G.R.

    1994-09-06

    An improved leak detection method is provided that utilizes the cyclic adsorption and desorption of accumulated helium on a non-porous metallic surface. The method provides reliable leak detection at superfluid helium temperatures. The zero drift that is associated with residual gas analyzers in common leak detectors is virtually eliminated by utilizing a time integration technique. The sensitivity of the apparatus of this disclosure is capable of detecting leaks as small as 1 [times] 10[sup [minus]18] atm cc sec[sup [minus]1]. 2 figs.

  1. High sensitivity leak detection method and apparatus

    DOEpatents

    Myneni, Ganapatic R.

    1994-01-01

    An improved leak detection method is provided that utilizes the cyclic adsorption and desorption of accumulated helium on a non-porous metallic surface. The method provides reliable leak detection at superfluid helium temperatures. The zero drift that is associated with residual gas analyzers in common leak detectors is virtually eliminated by utilizing a time integration technique. The sensitivity of the apparatus of this disclosure is capable of detecting leaks as small as 1.times.10.sup.-18 atm cc sec.sup.-1.

  2. Method for remote detection of trace contaminants

    DOEpatents

    Simonson, Robert J.; Hance, Bradley G.

    2003-09-09

    A method for remote detection of trace contaminants in a target area comprises applying sensor particles that preconcentrate the trace contaminant to the target area and detecting the contaminant-sensitive fluorescence from the sensor particles. The sensor particles can have contaminant-sensitive and contaminant-insensitive fluorescent compounds to enable the determination of the amount of trace contaminant present in the target are by relative comparison of the emission of the fluorescent compounds by a local or remote fluorescence detector. The method can be used to remotely detect buried minefields.

  3. [Detection method for blurred regions in radiographs].

    PubMed

    Muroi, Tomoya; Lee, Yongbum; Tsai, Du-Yih; Tsurumaki, Masaki

    2014-03-01

    In this paper, we propose a detection method for blurred regions in radiographs. The method involves edge detection using a Sobel filter, manually determining the region of interest (ROI), feature calculation, and classification using a support vector machine. We applied our method to 14 phantom images (7 normal images, 7 blurred images) and 14 clinical images (12 normal images, 2 blurred images). As a result, the average classification accuracies of ROIs with blurring and ROIs without blurring were 98% and 90% for phantom images and clinical images, respectively.

  4. An enhanced Monte Carlo outlier detection method.

    PubMed

    Zhang, Liangxiao; Li, Peiwu; Mao, Jin; Ma, Fei; Ding, Xiaoxia; Zhang, Qi

    2015-09-30

    Outlier detection is crucial in building a highly predictive model. In this study, we proposed an enhanced Monte Carlo outlier detection method by establishing cross-prediction models based on determinate normal samples and analyzing the distribution of prediction errors individually for dubious samples. One simulated and three real datasets were used to illustrate and validate the performance of our method, and the results indicated that this method outperformed Monte Carlo outlier detection in outlier diagnosis. After these outliers were removed, the value of validation by Kovats retention indices and the root mean square error of prediction decreased from 3.195 to 1.655, and the average cross-validation prediction error decreased from 2.0341 to 1.2780. This method helps establish a good model by eliminating outliers. © 2015 Wiley Periodicals, Inc.

  5. Method of Fault Detection and Rerouting

    NASA Technical Reports Server (NTRS)

    Medelius, Pedro J. (Inventor); Gibson, Tracy L. (Inventor); Lewis, Mark E. (Inventor)

    2013-01-01

    A system and method for detecting damage in an electrical wire, including delivering at least one test electrical signal to an outer electrically conductive material in a continuous or non-continuous layer covering an electrically insulative material layer that covers an electrically conductive wire core. Detecting the test electrical signals in the outer conductive material layer to obtain data that is processed to identify damage in the outer electrically conductive material layer.

  6. Novel Methods for Detecting Buried Explosive Devices

    DTIC Science & Technology

    2007-04-10

    NQR ), and semiotic data fusion. Bioreporter bacteria look promising for third-world humanitarian applications; they are inexpensive, and...demining, NQR is a promising method for detecting explosive substances; of 50,000 substances that have been tested, none has an NQR signature that can be...approach to a cheap mine detector for humanitarian use. Real-time wavelet processing appears to be a key to extending NQR bomb detection into mine

  7. Automated macromolecular crystal detection system and method

    DOEpatents

    Christian, Allen T.; Segelke, Brent; Rupp, Bernard; Toppani, Dominique

    2007-06-05

    An automated macromolecular method and system for detecting crystals in two-dimensional images, such as light microscopy images obtained from an array of crystallization screens. Edges are detected from the images by identifying local maxima of a phase congruency-based function associated with each image. The detected edges are segmented into discrete line segments, which are subsequently geometrically evaluated with respect to each other to identify any crystal-like qualities such as, for example, parallel lines, facing each other, similarity in length, and relative proximity. And from the evaluation a determination is made as to whether crystals are present in each image.

  8. Detection methods for autologous blood doping.

    PubMed

    Segura, J; Monfort, N; Ventura, R

    2012-11-01

    The use of blood doping is forbidden by the World Anti-Doping Agency. Several practices, such as blood transfusions are used to increase oxygen delivery to muscles and all of them are highly pursued. In this regard, the development of accurate methodologies for detecting these prohibited practices is one of the current aims of the anti-doping control laboratories. Flow cytometry methods are able to detect allogeneic blood transfusions but there is no official methodology available to detect autologous blood transfusions. This paper reviews protocols, including the Athlete Biological Passport, that use indirect markers to detect misuse of blood transfusions, especially autologous blood transfusions. The methods of total haemoglobin mass measurements and the detection of metabolites of blood bags plasticizers in urine are reviewed. The latter seems to be an important step forward because it is a fast screening method and it is based on urine, a fluid widely available for doping control. Other innovative approaches to blood transfusion detection are also mentioned. A combination of the reported methodologies and the implementation of the Athlete Biological Passport is becoming a promising approach.

  9. Three Methods of Detection of Hydrazines

    NASA Technical Reports Server (NTRS)

    Griffin, Timothy; Berger, Cristina

    2010-01-01

    Three proposed methods for measuring trace quantities of hydrazines involve ionization and detection of hydrazine derivatives. These methods are intended to overcome the limitations of prior hydrazine- detection methods. Hydrazine (Hz), monomethylhydrazine (MMH), and unsymmetrical dimethylhydrazine (UDMH) are hypergolic fuels and are highly reactive, toxic, and corrosive. A capability to measure concentrations of hydrazines is desirable for detecting leaks and ensuring safety in aerospace settings and in some industrial settings in which these compounds are used. One of the properties (high reactivity) that make it desirable to detect trace amounts of hydrazines also makes it difficult to detect hydrazines and measure their concentrations accurately using prior methods: significant amounts are lost to thermal and catalytic decomposition prior to detection. Further complications arise from the sticky nature of hydrazines: Sample hydrazine molecules tend to become irreversibly adsorbed onto solid surfaces with which they come into contact during transport to detectors, giving rise to drift in detector responses. In each proposed method, the reactive, sticky nature of hydrazines would be turned to advantage by providing a suitably doped substrate surface with which the hydrazines would react. The resulting hydrazine derivatives would be sufficiently less sticky and sufficiently more stable so that fewer molecules would be lost to decomposition or adsorption during transport. Consequently, it would be possible to measure concentration with more sensitivity and less error than in prior techniques. The first proposed method calls for the use of a recently developed technique known as desorption electrospray ionization (DESI), in which a pneumatically assisted micro -electrospray at ambient pressure is directed at a surface of interest. In this case, the surface of interest would be that of a substrate described above.

  10. Apparatus and methods for detecting chemical permeation

    DOEpatents

    Vo-Dinh, T.

    1994-12-27

    Apparatus and methods for detecting the permeation of hazardous or toxic chemicals through protective clothing are disclosed. The hazardous or toxic chemicals of interest do not possess the spectral characteristic of luminescence. The apparatus and methods utilize a spectrochemical modification technique to detect the luminescence quenching of an indicator compound which upon permeation of the chemical through the protective clothing, the indicator is exposed to the chemical, thus indicating chemical permeation. The invention also relates to the fabrication of protective clothing materials. 13 figures.

  11. Methods for detection of irradiation of spices.

    PubMed

    Sjöberg, A M; Manninen, M; Härmälä, P; Pinnioja, S

    1990-02-01

    Three types of methods for the identification of irradiation of spices were tested as potential control methods. The methods were microbiological, combining a direct epifluorescent filter technique (DEFT) with a total aerobic plate count (APC), a chemiluminescence method and chemical gas-chromatographic (GC) and GC mass-spectrometric (MS) methods for analysis of volatile oils of spices isolated by steam distillation. Twelve samples of spices, mainly peppers, were analysed before and after gamma-irradiation with doses of 10 and 50 kGy. The chemiluminescence measurements were performed before the irradiation and 10 and 100 days after the irradiation. The best methods for control purposes were the microbiological (DEFT + APC) methods combined with chemiluminescence measurements. No differences were detected between the irradiated and non-irradiated samples with the chemical methods.

  12. Novel methods for detecting buried explosive devices

    SciTech Connect

    Kercel, S.W.; Burlage, R.S.; Patek, D.R.; Smith, C.M.; Hibbs, A.D.; Rayner, T.J.

    1997-04-01

    Oak Ridge National Laboratory (ORNL) and Quantum Magnetics, Inc. (QM) are exploring novel landmine detection technologies. Technologies considered here include bioreporter bacteria, swept acoustic resonance, nuclear quadrupole resonance (NQR), and semiotic data fusion. Bioreporter bacteria look promising for third-world humanitarian applications; they are inexpensive, and deployment does not require high-tech methods. Swept acoustic resonance may be a useful adjunct to magnetometers in humanitarian demining. For military demining, NQR is a promising method for detecting explosive substances; of 50,000 substances that have been tested, none has an NQR signature that can be mistaken for RDX or TNT. For both military and commercial demining, sensor fusion entails two daunting tasks, identifying fusible features in both present-day and emerging technologies, and devising a fusion algorithm that runs in real-time on cheap hardware. Preliminary research in these areas is encouraging. A bioreporter bacterium for TNT detection is under development. Investigation has just started in swept acoustic resonance as an approach to a cheap mine detector for humanitarian use. Real-time wavelet processing appears to be a key to extending NQR bomb detection into mine detection, including TNT-based mines. Recent discoveries in semiotics may be the breakthrough that will lead to a robust fused detection scheme.

  13. Flow cytometric detection method for DNA samples

    DOEpatents

    Nasarabadi, Shanavaz [Livermore, CA; Langlois, Richard G [Livermore, CA; Venkateswaran, Kodumudi S [Round Rock, TX

    2011-07-05

    Disclosed herein are two methods for rapid multiplex analysis to determine the presence and identity of target DNA sequences within a DNA sample. Both methods use reporting DNA sequences, e.g., modified conventional Taqman.RTM. probes, to combine multiplex PCR amplification with microsphere-based hybridization using flow cytometry means of detection. Real-time PCR detection can also be incorporated. The first method uses a cyanine dye, such as, Cy3.TM., as the reporter linked to the 5' end of a reporting DNA sequence. The second method positions a reporter dye, e.g., FAM.TM. on the 3' end of the reporting DNA sequence and a quencher dye, e.g., TAMRA.TM., on the 5' end.

  14. Flow cytometric detection method for DNA samples

    DOEpatents

    Nasarabadi, Shanavaz; Langlois, Richard G.; Venkateswaran, Kodumudi S.

    2006-08-01

    Disclosed herein are two methods for rapid multiplex analysis to determine the presence and identity of target DNA sequences within a DNA sample. Both methods use reporting DNA sequences, e.g., modified conventional Taqman.RTM. probes, to combine multiplex PCR amplification with microsphere-based hybridization using flow cytometry means of detection. Real-time PCR detection can also be incorporated. The first method uses a cyanine dye, such as, Cy3.TM., as the reporter linked to the 5' end of a reporting DNA sequence. The second method positions a reporter dye, e.g., FAM, on the 3' end of the reporting DNA sequence and a quencher dye, e.g., TAMRA, on the 5' end.

  15. A new point target detection method

    NASA Astrophysics Data System (ADS)

    Lv, Baolin; Tong, Shoufeng; Wang, Dejiang; Liu, Rang

    2017-09-01

    This paper proposes a new point target detection method based on multiscale morphological filtering and local characteristic criterion. First 8-directions morphological Top-hat transform are used to detect all the possible targets with different scales. Next, the adaptive threshold is adopt to obtain the Region of Interest (RoI) of the target and improve signal to noise ratio (SNR). Secondly, we remove the remaining background edges according to the local characteristic criterion between background edges and point targets. Finally, we make use of the matching relationship of interframe to remove noise and obtain point target trajectory. And the point target is successfully detected out in motion control system. The results show that the proposed method has a good performance to suppress complex background and meet real-time requirement.

  16. Method for detecting gas turbine engine flashback

    SciTech Connect

    Singh, Kapil Kumar; Varatharajan, Balachandar; Kraemer, Gilbert Otto; Yilmaz, Ertan; Lacy, Benjamin Paul

    2012-09-04

    A method for monitoring and controlling a gas turbine, comprises predicting frequencies of combustion dynamics in a combustor using operating conditions of a gas turbine, receiving a signal from a sensor that is indicative of combustion dynamics in the combustor, and detecting a flashback if a frequency of the received signal does not correspond to the predicted frequencies.

  17. Method and apparatus for detecting an analyte

    DOEpatents

    Allendorf, Mark D [Pleasanton, CA; Hesketh, Peter J [Atlanta, GA

    2011-11-29

    We describe the use of coordination polymers (CP) as coatings on microcantilevers for the detection of chemical analytes. CP exhibit changes in unit cell parameters upon adsorption of analytes, which will induce a stress in a static microcantilever upon which a CP layer is deposited. We also describe fabrication methods for depositing CP layers on surfaces.

  18. Improved astigmatic focus error detection method

    NASA Technical Reports Server (NTRS)

    Bernacki, Bruce E.

    1992-01-01

    All easy-to-implement focus- and track-error detection methods presently used in magneto-optical (MO) disk drives using pre-grooved media suffer from a side effect known as feedthrough. Feedthrough is the unwanted focus error signal (FES) produced when the optical head is seeking a new track, and light refracted from the pre-grooved disk produces an erroneous FES. Some focus and track-error detection methods are more resistant to feedthrough, but tend to be complicated and/or difficult to keep in alignment as a result of environmental insults. The astigmatic focus/push-pull tracking method is an elegant, easy-to-align focus- and track-error detection method. Unfortunately, it is also highly susceptible to feedthrough when astigmatism is present, with the worst effects caused by astigmatism oriented such that the tangential and sagittal foci are at 45 deg to the track direction. This disclosure outlines a method to nearly completely eliminate the worst-case form of feedthrough due to astigmatism oriented 45 deg to the track direction. Feedthrough due to other primary aberrations is not improved, but performance is identical to the unimproved astigmatic method.

  19. Morphological detection method with girdle structure

    NASA Astrophysics Data System (ADS)

    Chen, Yong; Yan, Gao-shi; Huo, Yu

    2013-09-01

    A flat structure element is usually used in the traditional morphological detection. In this processing method, the infrared target is regarded as a single point without considering the imaging characteristics of infrared dim and small target. There is a gray transition zone between target and background. It is unreasonable that the transition region processed as background in the traditional morphological method. So, the infrared dim target detection results are not ideal by using the traditional morphological processing method. Aimed at this problem, the imaging characteristic of infrared dim and small target is analyzed. The Spatial distribution of infrared target gray scale is calculated. The result shows it is a tip package structure. The top peak is the target. Based on theoretical research on the morphological detection, the girdle structure elements are designed. This structure is composed of two circles. The target neighborhood zones are protected in this structure. They do not participate in the morphological calculation. The sixteen external zones are only participated in the calculation. The morphology of infrared target detection method is established based on this neighborhood zoned structure. The designed girdle structure is used in the opening operation and the traditional flat structure is used in the closing operation. The traditional Top-Hat algorithm is improved according to the girdle structure morphology method. And used the real infrared target image, the improved algorithm is simulated. The processed result shows that the girdle structure morphology method is effective in the background noise restraining. In order to evaluate the image processed result quantitatively, the signal noise ratio and signal noise ratio gain factor are used. Accordingly to the calculated result, the improved algorithm compared with the traditional morphological methods, inhibition of complex background with better.

  20. Morphological boundary detecting method in cineangiogram image

    NASA Astrophysics Data System (ADS)

    Gui, Feng; Lin, QiWei

    2002-04-01

    Atherosclerotic coronary heart disease (CHD) is one of the commonest diseases that is heavily hazardous to people's health. Wall motion abnormalities of L.V. due to myocardia ischeamia caused by coronary atherosclerosis is a significant feature of CHD. This paper was designed to build up a foundation for automatic detection of L.V. contours according to the features of L.V. cineangiograms, for a further study of L.V. wall motion abnormalities. An algorithm that based on morphology for L.V. contours extracting was developed in this paper. As we know morphology is a kind of technique based upon set theory and it can be used for binary image and gray image processing. The principle and the geometrical meaning of morphological boundary detecting for image were discussed in this paper, and the selection of structuring element was analyzed. Comparison was made between morphological boundary detecting and traditional boundary detecting method, conclusion that morphological boundary detecting method has better compatibility and anti-interference capability was reached.

  1. Fault detection with principal component pursuit method

    NASA Astrophysics Data System (ADS)

    Pan, Yijun; Yang, Chunjie; Sun, Youxian; An, Ruqiao; Wang, Lin

    2015-11-01

    Data-driven approaches are widely applied for fault detection in industrial process. Recently, a new method for fault detection called principal component pursuit(PCP) is introduced. PCP is not only robust to outliers, but also can accomplish the objectives of model building, fault detection, fault isolation and process reconstruction simultaneously. PCP divides the data matrix into two parts: a fault-free low rank matrix and a sparse matrix with sensor noise and process fault. The statistics presented in this paper fully utilize the information in data matrix. Since the low rank matrix in PCP is similar to principal components matrix in PCA, a T2 statistic is proposed for fault detection in low rank matrix. And this statistic can illustrate that PCP is more sensitive to small variations in variables than PCA. In addition, in sparse matrix, a new monitored statistic performing the online fault detection with PCP-based method is introduced. This statistic uses the mean and the correlation coefficient of variables. Monte Carlo simulation and Tennessee Eastman (TE) benchmark process are provided to illustrate the effectiveness of monitored statistics.

  2. Detection methods for centrifugal microfluidic platforms.

    PubMed

    Burger, Robert; Amato, Letizia; Boisen, Anja

    2016-02-15

    Centrifugal microfluidics has attracted much interest from academia as well as industry, since it potentially offers solutions for affordable, user-friendly and portable biosensing. A wide range of so-called fluidic unit operations, e.g. mixing, metering, liquid routing, and particle separation, have been developed and allow automation and integration of complex assay protocols in lab-on-a-disc systems. Besides liquid handling, the detection strategy for reading out the assay is crucial for developing a fully integrated system. In this review, we focus on biosensors and readout methods for the centrifugal microfluidics platform and cover optical as well as mechanical and electrical detection principles.

  3. Method and system for detecting an explosive

    DOEpatents

    Reber, Edward L.; Rohde, Kenneth W.; Blackwood, Larry G.

    2010-12-07

    A method and system for detecting at least one explosive in a vehicle using a neutron generator and a plurality of NaI detectors. Spectra read from the detectors is calibrated by performing Gaussian peak fitting to define peak regions, locating a Na peak and an annihilation peak doublet, assigning a predetermined energy level to one peak in the doublet, and predicting a hydrogen peak location based on a location of at least one peak of the doublet. The spectra are gain shifted to a common calibration, summed for respective groups of NaI detectors, and nitrogen detection analysis performed on the summed spectra for each group.

  4. A novel method for detection of apoptosis

    SciTech Connect

    Zagariya, Alexander M.

    2012-04-15

    There are two different Angiotensin II (ANG II) peptides in nature: Human type (ANG II) and Bovine type (ANG II*). These eight amino acid peptides differ only at position 5 where Valine is replaced by Isoleucine in the Bovine type. They are present in all species studied so far. These amino acids are different by only one atom of carbon. This difference is so small, that it will allow any of ANG II, Bovine or Human antibodies to interact with all species and create a universal method for apoptosis detection. ANG II concentrations are found at substantially higher levels in apoptotic, compared to non-apoptotic, tissues. ANG II accumulation can lead to DNA damage, mutations, carcinogenesis and cell death. We demonstrate that Bovine antiserum can be used for universal detection of apoptosis. In 2010, the worldwide market for apoptosis detection reached the $20 billion mark and significantly increases each year. Most commercially available methods are related to Annexin V and TUNNEL. Our new method based on ANG II is more widely known to physicians and scientists compared to previously used methods. Our approach offers a novel alternative for assessing apoptosis activity with enhanced sensitivity, at a lower cost and ease of use.

  5. Molecular methods for the detection of mutations.

    PubMed

    Monteiro, C; Marcelino, L A; Conde, A R; Saraiva, C; Giphart-Gassler, M; De Nooij-van Dalen, A G; Van Buuren-van Seggelen, V; Van der Keur, M; May, C A; Cole, J; Lehmann, A R; Steinsgrimsdottir, H; Beare, D; Capulas, E; Armour, J A

    2000-01-01

    We report the results of a collaborative study aimed at developing reliable, direct assays for mutation in human cells. The project used common lymphoblastoid cell lines, both with and without mutagen treatment, as a shared resource to validate the development of new molecular methods for the detection of low-level mutations in the presence of a large excess of normal alleles. As the "gold standard, " hprt mutation frequencies were also measured on the same samples. The methods under development included i) the restriction site mutation (RSM) assay, in which mutations lead to the destruction of a restriction site; ii) minisatellite length-change mutation, in which mutations lead to alleles containing new numbers of tandem repeat units; iii) loss of heterozygosity for HLA epitopes, in which antibodies can be used to direct selection for mutant cells; iv) multiple fluorescence-based long linker arm nucleotides assay (mf-LLA) technology, for the detection of substitutional mutations; v) detection of alterations in the TP53 locus using a (CA) array as the target for the screening; and vi) PCR analysis of lymphocytes for the presence of the BCL2 t(14:18) translocation. The relative merits of these molecular methods are discussed, and a comparison made with more "traditional" methods.

  6. Need for new caries detection methods

    NASA Astrophysics Data System (ADS)

    Young, Douglas A.; Featherstone, John D. B.

    1999-05-01

    Dental caries (tooth decay) continues to be a major problems for adults as well as children, even though great advances have been made in preventive methods in the last 20 years. New methods for the management of caries will work best if lesions can be detected at an early stage and chemical rather than physical intervention can take place, thereby preserving the natural tooth structure and helping the saliva to heal, or remineralize, the areas of early decay. Clinical detection of caries in the US relies on visual examination, tactile with hand held explorer, and conventional radiographs, all of which are inadequate for the occlusal (biting) surfaces of the teeth where most of the decay now occurs. The dentist often has to explore by drilling with a dental bur to confirm early decay in these areas. New method that can determine the extent and degree of subsurface lesions in these surfaces non-destructively are essential for further advances in the clinical management of dental caries. Optical methods, which exploit the differences between sound and carious enamel and dentin, show great promise for the accurate detection of these lesions. Two or three- dimensional images, which include a measure of severity will be needed.

  7. Analytical Methods for Exoplanet Imaging Detection Metrics

    NASA Astrophysics Data System (ADS)

    Garrett, Daniel; Savransky, Dmitry

    2017-01-01

    When designing or simulating exoplanet-finding missions, a selection metric must be used to choose which target stars will be observed. For direct imaging missions, the metric is a function of the planet-star separation and flux ratio as constrained by the instrument's inner and outer working angles and contrast. We present analytical methods for the calculation of two detection metrics: completeness and depth of search. While Monte Carlo methods have typically been used for determining each of these detection metrics, implementing analytical methods in simulation or early stage design yields quicker, more accurate calculations.Completeness is the probability of detecting a planet belonging to the planet population of interest. This metric requires assumptions to be made about the planet population. Probability density functions are assumed for the planetary parameters of semi-major axis, eccentricity, geometric albedo, and planetary radius. Planet-star separation and difference in brightness magnitude or contrast are written as functions of these parameters. A change of variables is performed to get a joint probability density function of planet-star separation and difference in brightness magnitude or contrast. This joint probability density function is marginalized subject to the constraints of the instrument to yield the probability of detecting a planet belonging to the population of interest.Depth of search for direct imaging is the sum of the probability of detecting a planet of given semi-major axis and planetary radius by a given instrument for a target list. This metric does not depend on assumed planet population parameter distributions. A two-dimensional grid of probabilities is generated for each star in the target list. The probability at each point in the grid is found by marginalizing a probability density function of contrast given constant values of semi-major axis and planetary radius subject to the constraints of the instrument.

  8. Research and Design of Rootkit Detection Method

    NASA Astrophysics Data System (ADS)

    Liu, Leian; Yin, Zuanxing; Shen, Yuli; Lin, Haitao; Wang, Hongjiang

    Rootkit is one of the most important issues of network communication systems, which is related to the security and privacy of Internet users. Because of the existence of the back door of the operating system, a hacker can use rootkit to attack and invade other people's computers and thus he can capture passwords and message traffic to and from these computers easily. With the development of the rootkit technology, its applications are more and more extensive and it becomes increasingly difficult to detect it. In addition, for various reasons such as trade secrets, being difficult to be developed, and so on, the rootkit detection technology information and effective tools are still relatively scarce. In this paper, based on the in-depth analysis of the rootkit detection technology, a new kind of the rootkit detection structure is designed and a new method (software), X-Anti, is proposed. Test results show that software designed based on structure proposed is much more efficient than any other rootkit detection software.

  9. Chemical detection system and related methods

    DOEpatents

    Caffrey, Augustine J.; Chichester, David L.; Egger, Ann E.; Krebs, Kenneth M.; Seabury, Edward H.; Van Siclen, Clinton D.; Wharton, C. Jayson; Zabriskie, John M.

    2017-06-27

    A chemical detection system includes a frame, an emitter coupled to the frame, and a detector coupled to the frame proximate the emitter. The system also includes a shielding system coupled to the frame and positioned at least partially between the emitter and the detector, wherein the frame positions a sensing surface of the detector in a direction substantially parallel to a plane extending along a front portion of the frame. A method of analyzing composition of a suspect object includes directing neutrons at the object, detecting gamma rays emitted from the object, and communicating spectrometer information regarding the gamma rays. The method also includes presenting a GUI to a user with a dynamic status of an ongoing neutron spectroscopy process. The dynamic status includes a present confidence for a plurality of compounds being present in the suspect object responsive to changes in the spectrometer information during the ongoing process.

  10. System and method for anomaly detection

    DOEpatents

    Scherrer, Chad

    2010-06-15

    A system and method for detecting one or more anomalies in a plurality of observations is provided. In one illustrative embodiment, the observations are real-time network observations collected from a stream of network traffic. The method includes performing a discrete decomposition of the observations, and introducing derived variables to increase storage and query efficiencies. A mathematical model, such as a conditional independence model, is then generated from the formatted data. The formatted data is also used to construct frequency tables which maintain an accurate count of specific variable occurrence as indicated by the model generation process. The formatted data is then applied to the mathematical model to generate scored data. The scored data is then analyzed to detect anomalies.

  11. Surface property detection apparatus and method

    DOEpatents

    Martens, J.S.; Ginley, D.S.; Hietala, V.M.; Sorensen, N.R.

    1995-08-08

    Apparatus and method for detecting, determining, and imaging surface resistance corrosion, thin film growth, and oxide formation on the surface of conductors or other electrical surface modification. The invention comprises a modified confocal resonator structure with the sample remote from the radiating mirror. Surface resistance is determined by analyzing and imaging reflected microwaves; imaging reveals anomalies due to surface impurities, non-stoichiometry, and the like, in the surface of the superconductor, conductor, dielectric, or semiconductor. 4 figs.

  12. Surface property detection apparatus and method

    DOEpatents

    Martens, Jon S.; Ginley, David S.; Hietala, Vincent M.; Sorensen, Neil R.

    1995-01-01

    Apparatus and method for detecting, determining, and imaging surface resistance corrosion, thin film growth, and oxide formation on the surface of conductors or other electrical surface modification. The invention comprises a modified confocal resonator structure with the sample remote from the radiating mirror. Surface resistance is determined by analyzing and imaging reflected microwaves; imaging reveals anomalies due to surface impurities, non-stoichiometry, and the like, in the surface of the superconductor, conductor, dielectric, or semiconductor.

  13. Seismic Anomaly Detection Using Symbolic Representation Methods

    NASA Astrophysics Data System (ADS)

    Christodoulou, Vyron; Bi, Yaxin; Wilkie, George; Zhao, Guoze

    2016-08-01

    In this work we investigate the use of symbolic representation methods for Anomaly Detection in different electromagnetic sequential time series datasets. An issue that is often overlooked regarding symbolic representation and its performance in Anomaly Detection is the use of a quantitative accuracy metric. Until recently only visual representations have been used to show the efficiency of an algorithm to detect anomalies. In this respect we propose an novel accuracy metric that takes into account the length of the sliding window of such symbolic representation algorithms and we present its utility. For the evaluation of the accuracy metric, HOT-SAX is used, a method that aggregates data points by use of sliding windows. A HOT-SAX variant, with the use of overlapping windows, is also introduced that achieves better results based on the newly defined accuracy metric. Both methods are evaluated on ten different benchmark datasets and based on the empirical evidence we use Earth's geomagnetic data gathered by the SWARM satellites and terrestrial sources around the epicenter of two seismic events in the Yunnan region of China.

  14. Improved method for detection of starch hydrolysis

    SciTech Connect

    Ohawale, M.R.; Wilson, J.J.; Khachatourians, G.G.; Ingledew, W.M.

    1982-09-01

    A new starch hydrolysis detection method which does not rely on iodine staining or the use of color-complexed starch is described. A linear relationship was obtained with agar-starch plates when net clearing zones around colonies of yeasts were plotted against enzyme levels (semilogarithm scale) produced by the same yeast strains in liquid medium. A similar relationship between starch clearing zones and alpha-amylase levels from three different sources was observed. These observations suggest that the method is useful in mutant isolations, strain improvement programs, and the prediction of alpha-amylase activities in culture filtrates or column effluents. (Refs. 18).

  15. Detection Method of TOXOPLASMA GONDII Tachyzoites

    NASA Astrophysics Data System (ADS)

    Eassa, Souzan; Bose, Chhanda; Alusta, Pierre; Tarasenko, Olga

    2011-06-01

    Tachyzoites are considered to be the most important stage of Toxoplasma gondii which causes toxoplasmosis. T. gondii is, an obligate intracellular parasite which infects a wide range of cells. The present study was designed to develop a method for an early detection of T. gondii tachyzoites. The method comprised of a binding assay which was analyzed using principal component and cluster analysis. Our data showed that glycoconjugates GC1, GC2, GC3 and GC10 exhibit a significantly higher binding affinity for T. gondii tachyzoites as compared to controls (T. gondii only, PAA only, GC 1, 2, 3, and 10 only).

  16. An AVAF inversion method for detecting hydrocarbons

    NASA Astrophysics Data System (ADS)

    Luo, Chunmei; Sen, Mrinal K.; Wang, Shangxu; Yuan, Sanyi

    2017-10-01

    Rock physics studies have shown that velocity dispersion is often associated with hydrocarbon deposit, which results in P-wave reflection coefficients varying with frequency. This effect is often neglected in the conventional amplitude versus angle or offset inversion, and thus error is introduced. Here we propose a method for inverting for dispersive velocity from the frequency-dependent P-wave reflection coefficients; the method is called amplitude variation with angle and frequency AVAF inversion. We employ forward modeling based on propagator matrices that include frequency-dependent elastic coefficients and a variant of the simulated annealing method called the heat-bath algorithm for inversion of layer parameters. In our application, the thickness of the dispersive layer is inverted for simultaneously. Synthetic and field data examples demonstrate the ability and usefulness of this method for detecting hydrocarbon bearing formations.

  17. Waterborne Pathogens: Detection Methods and Challenges

    PubMed Central

    Ramírez-Castillo, Flor Yazmín; Loera-Muro, Abraham; Jacques, Mario; Garneau, Philippe; Avelar-González, Francisco Javier; Harel, Josée; Guerrero-Barrera, Alma Lilián

    2015-01-01

    Waterborne pathogens and related diseases are a major public health concern worldwide, not only by the morbidity and mortality that they cause, but by the high cost that represents their prevention and treatment. These diseases are directly related to environmental deterioration and pollution. Despite the continued efforts to maintain water safety, waterborne outbreaks are still reported globally. Proper assessment of pathogens on water and water quality monitoring are key factors for decision-making regarding water distribution systems’ infrastructure, the choice of best water treatment and prevention waterborne outbreaks. Powerful, sensitive and reproducible diagnostic tools are developed to monitor pathogen contamination in water and be able to detect not only cultivable pathogens but also to detect the occurrence of viable but non-culturable microorganisms as well as the presence of pathogens on biofilms. Quantitative microbial risk assessment (QMRA) is a helpful tool to evaluate the scenarios for pathogen contamination that involve surveillance, detection methods, analysis and decision-making. This review aims to present a research outlook on waterborne outbreaks that have occurred in recent years. This review also focuses in the main molecular techniques for detection of waterborne pathogens and the use of QMRA approach to protect public health. PMID:26011827

  18. Detection of Respiratory Viruses by Molecular Methods

    PubMed Central

    Mahony, James B.

    2008-01-01

    Summary: Clinical laboratories historically diagnose seven or eight respiratory virus infections using a combination of techniques including enzyme immunoassay, direct fluorescent antibody staining, cell culture, and nucleic acid amplification tests. With the discovery of six new respiratory viruses since 2000, laboratories are faced with the challenge of detecting up to 19 different viruses that cause acute respiratory disease of both the upper and lower respiratory tracts. The application of nucleic acid amplification technology, particularly multiplex PCR coupled with fluidic or fixed microarrays, provides an important new approach for the detection of multiple respiratory viruses in a single test. These multiplex amplification tests provide a sensitive and comprehensive approach for the diagnosis of respiratory tract infections in individual hospitalized patients and the identification of the etiological agent in outbreaks of respiratory tract infection in the community. This review describes the molecular methods used to detect respiratory viruses and discusses the contribution that molecular testing, especially multiplex PCR, has made to our ability to detect respiratory viruses and to increase our understanding of the roles of various viral agents in acute respiratory disease. PMID:18854489

  19. Waterborne pathogens: detection methods and challenges.

    PubMed

    Ramírez-Castillo, Flor Yazmín; Loera-Muro, Abraham; Jacques, Mario; Garneau, Philippe; Avelar-González, Francisco Javier; Harel, Josée; Guerrero-Barrera, Alma Lilián

    2015-05-21

    Waterborne pathogens and related diseases are a major public health concern worldwide, not only by the morbidity and mortality that they cause, but by the high cost that represents their prevention and treatment. These diseases are directly related to environmental deterioration and pollution. Despite the continued efforts to maintain water safety, waterborne outbreaks are still reported globally. Proper assessment of pathogens on water and water quality monitoring are key factors for decision-making regarding water distribution systems' infrastructure, the choice of best water treatment and prevention waterborne outbreaks. Powerful, sensitive and reproducible diagnostic tools are developed to monitor pathogen contamination in water and be able to detect not only cultivable pathogens but also to detect the occurrence of viable but non-culturable microorganisms as well as the presence of pathogens on biofilms. Quantitative microbial risk assessment (QMRA) is a helpful tool to evaluate the scenarios for pathogen contamination that involve surveillance, detection methods, analysis and decision-making. This review aims to present a research outlook on waterborne outbreaks that have occurred in recent years. This review also focuses in the main molecular techniques for detection of waterborne pathogens and the use of QMRA approach to protect public health.

  20. Current methods for detecting ethylene in plants

    PubMed Central

    Cristescu, Simona M.; Mandon, Julien; Arslanov, Denis; De Pessemier, Jérôme; Hermans, Christian; Harren, Frans J. M.

    2013-01-01

    Background In view of ethylene's critical developmental and physiological roles the gaseous hormone remains an active research topic for plant biologists. Progress has been made to understand the ethylene biosynthesis pathway and the mechanisms of perception and action. Still numerous questions need to be answered and findings to be validated. Monitoring gas production will very often complete the picture of any ethylene research topic. Therefore the search for suitable ethylene measuring methods for various plant samples either in the field, greenhouses, laboratories or storage facilities is strongly motivated. Scope This review presents an update of the current methods for ethylene monitoring in plants. It focuses on the three most-used methods – gas chromatography detection, electrochemical sensing and optical detection – and compares them in terms of sensitivity, selectivity, time response and price. Guidelines are provided for proper selection and application of the described sensor methodologies and some specific applications are illustrated of laser-based detector for monitoring ethylene given off by Arabidopsis thaliana upon various nutritional treatments. Conclusions Each method has its advantages and limitations. The choice for the suitable ethylene sensor needs careful consideration and is driven by the requirements for a specific application. PMID:23243188

  1. A new method for FMRI activation detection

    NASA Astrophysics Data System (ADS)

    Wei, Jianing; Talavage, Thomas M.; Pollak, Ilya

    2009-02-01

    The objective of fMRI data analysis is to detect the region of the brain that gets activated in response to a specific stimulus presented to the subject. We develop a new algorithm for activation detection in event-related fMRI data. We utilize a forward model for fMRI data acquisition which explicitly incorporates physiological noise, scanner noise and the spatial blurring introduced by the scanner. After slice-by-slice image restoration procedure that independently restores each data slice corresponding to each time index, we estimate the parameters of the hemodynamic response function (HRF) model for each pixel of the restored data. In order to enforce spatial regularity in our estimates, we model the prior distribution of the HRF parameters as a generalized Gaussian Markov random field (GGMRF) model. We develop an algorithm to compute the maximum a posteriori (MAP) estimates of the parameters. We then threshold the amplitude parameters to obtain the final activation map. We illustrate our algorithm by comparing it with the widely used general linear model (GLM) method. In synthetic data experiments, under the same probability of false alarm, the probability of correct detection for our method is up to 15% higher than GLM. In real data experiments, through anatomical analysis and benchmark testing using block paradigm results, we demonstrate that our algorithm produces fewer false alarms than GLM.

  2. Halocarbon refrigerant detection methods. Final report

    SciTech Connect

    Tapscott, R.E.; Sohn, C.W.

    1996-01-01

    The Montreal Protocol and the U.S. Clean Air Act limit the production of ozone-depleting substances, including many refrigerants. Three options for cost-effectively phasing out these refrigerants from Army installations are: (1) refrigerant containment, (2) retrofit conversion to accommodate alternative refrigerant, and (3) replacement with cooling systems using alternative refrigerant. This report contributes to the first option by identifying and assessing methods to detect chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC) and hydrofluorocarbon (HFC) refrigerants that leak from air-conditioning and refrigeration systems. As background, the report describes the relevant sections of the Montreal Protocol and the Clean Air Act, and gives an overview of refrigerants. This is followed by a description of the technologies used in refrigerant leak detection, and a survey of detector types available and their price ranges. Appendixes provide an extensive list of detector products and their specifications, plus manufacturer addresses and phone numbers.

  3. Correlation fluorescence method of amine detection

    NASA Astrophysics Data System (ADS)

    Myslitsky, Valentin F.; Tkachuk, Svetlana S.; Rudeichuk, Volodimir M.; Strinadko, Miroslav T.; Slyotov, Mikhail M.; Strinadko, Marina M.

    1997-12-01

    The amines fluorescence spectra stimulated by UV laser radiation are investigated in this paper. The fluorescence is stimulated by the coherent laser beam with the wavelength 0.337 micrometers . At the sufficient energy of laser stimulation the narrow peaks of the fluorescence spectra are detected besides the wide maximum. The relationship between the fluorescence intensity and the concentration of amines solutions are investigated. The fluorescence intensity temporal dependence on wavelength 0.363 micrometers of the norepinephrine solution preliminarily radiated by UV laser with wavelength 0.337 micrometers was found. The computer stimulated and experimental investigations of adrenaline and norepinephrine mixtures fluorescence spectra were done. The correlation fluorescent method of amines detection is proposed.

  4. ULTRASONIC FLAW DETECTION METHOD AND MEANS

    DOEpatents

    Worlton, D.C.

    1961-08-15

    A method of detecting subsurface flaws in an object using ultrasonic waves is described. An ultnasonic wave of predetermined velocity and frequency is transmitted to engage the surface of the object at a predetermined angle of inci dence thereto. The incident angle of the wave to the surface is determined with respect to phase velocity, incident wave velocity, incident wave frequency, and the estimated depth of the flaw so that Lamb waves of a particular type and mode are induced only in the portion of the object between the flaw and the surface. These Lamb waves are then detected as they leave the object at an angle of exit equal to the angle of incidence. No waves wlll be generated in the object and hence received if no flaw exists beneath the surface. (AEC)

  5. Method and apparatus for detecting neutrons

    DOEpatents

    Perkins, Richard W.; Reeder, Paul L.; Wogman, Ned A.; Warner, Ray A.; Brite, Daniel W.; Richey, Wayne C.; Goldman, Don S.

    1997-01-01

    The instant invention is a method for making and using an apparatus for detecting neutrons. Scintillating optical fibers are fabricated by melting SiO.sub.2 with a thermal neutron capturing substance and a scintillating material in a reducing atmosphere. The melt is then drawn into fibers in an anoxic atmosphere. The fibers may then be coated and used directly in a neutron detection apparatus, or assembled into a geometrical array in a second, hydrogen-rich, scintillating material such as a polymer. Photons generated by interaction with thermal neutrons are trapped within the coated fibers and are directed to photoelectric converters. A measurable electronic signal is generated for each thermal neutron interaction within the fiber. These electronic signals are then manipulated, stored, and interpreted by normal methods to infer the quality and quantity of incident radiation. When the fibers are arranged in an array within a second scintillating material, photons generated by kinetic neutrons interacting with the second scintillating material and photons generated by thermal neutron capture within the fiber can both be directed to photoelectric converters. These electronic signals are then manipulated, stored, and interpreted by normal methods to infer the quality and quantity of incident radiation.

  6. Method and apparatus for detecting neutrons

    DOEpatents

    Perkins, R.W.; Reeder, P.L.; Wogman, N.A.; Warner, R.A.; Brite, D.W.; Richey, W.C.; Goldman, D.S.

    1997-10-21

    The instant invention is a method for making and using an apparatus for detecting neutrons. Scintillating optical fibers are fabricated by melting SiO{sub 2} with a thermal neutron capturing substance and a scintillating material in a reducing atmosphere. The melt is then drawn into fibers in an anoxic atmosphere. The fibers may then be coated and used directly in a neutron detection apparatus, or assembled into a geometrical array in a second, hydrogen-rich, scintillating material such as a polymer. Photons generated by interaction with thermal neutrons are trapped within the coated fibers and are directed to photoelectric converters. A measurable electronic signal is generated for each thermal neutron interaction within the fiber. These electronic signals are then manipulated, stored, and interpreted by normal methods to infer the quality and quantity of incident radiation. When the fibers are arranged in an array within a second scintillating material, photons generated by kinetic neutrons interacting with the second scintillating material and photons generated by thermal neutron capture within the fiber can both be directed to photoelectric converters. These electronic signals are then manipulated, stored, and interpreted by normal methods to infer the quality and quantity of incident radiation. 5 figs.

  7. Bayesian Methods for Radiation Detection and Dosimetry

    SciTech Connect

    Peter G. Groer

    2002-09-29

    We performed work in three areas: radiation detection, external and internal radiation dosimetry. In radiation detection we developed Bayesian techniques to estimate the net activity of high and low activity radioactive samples. These techniques have the advantage that the remaining uncertainty about the net activity is described by probability densities. Graphs of the densities show the uncertainty in pictorial form. Figure 1 below demonstrates this point. We applied stochastic processes for a method to obtain Bayesian estimates of 222Rn-daughter products from observed counting rates. In external radiation dosimetry we studied and developed Bayesian methods to estimate radiation doses to an individual with radiation induced chromosome aberrations. We analyzed chromosome aberrations after exposure to gammas and neutrons and developed a method for dose-estimation after criticality accidents. The research in internal radiation dosimetry focused on parameter estimation for compartmental models from observed compartmental activities. From the estimated probability densities of the model parameters we were able to derive the densities for compartmental activities for a two compartment catenary model at different times. We also calculated the average activities and their standard deviation for a simple two compartment model.

  8. Method and apparatus for detecting explosives

    DOEpatents

    Moore, David Steven [Santa Fe, NM

    2011-05-10

    A method and apparatus is provided for detecting explosives by thermal imaging. The explosive material is subjected to a high energy wave which can be either a sound wave or an electromagnetic wave which will initiate a chemical reaction in the explosive material which chemical reaction will produce heat. The heat is then sensed by a thermal imaging device which will provide a signal to a computing device which will alert a user of the apparatus to the possibility of an explosive device being present.

  9. Systems and methods for detecting and processing

    DOEpatents

    Johnson, Michael M.; Yoshimura, Ann S.

    2006-03-28

    Embodiments of the present invention provides systems and method for detecting. Sensing modules are provided in communication with one or more detectors. In some embodiments, detectors are provided that are sensitive to chemical, biological, or radiological agents. Embodiments of sensing modules include processing capabilities to analyze, perform computations on, and/or run models to predict or interpret data received from one or more detectors. Embodiments of sensing modules form various network configurations with one another and/or with one or more data aggregation devices. Some embodiments of sensing modules include power management functionalities.

  10. Traumatic brain injury detection using electrophysiological methods.

    PubMed

    Rapp, Paul E; Keyser, David O; Albano, Alfonso; Hernandez, Rene; Gibson, Douglas B; Zambon, Robert A; Hairston, W David; Hughes, John D; Krystal, Andrew; Nichols, Andrew S

    2015-01-01

    Measuring neuronal activity with electrophysiological methods may be useful in detecting neurological dysfunctions, such as mild traumatic brain injury (mTBI). This approach may be particularly valuable for rapid detection in at-risk populations including military service members and athletes. Electrophysiological methods, such as quantitative electroencephalography (qEEG) and recording event-related potentials (ERPs) may be promising; however, the field is nascent and significant controversy exists on the efficacy and accuracy of the approaches as diagnostic tools. For example, the specific measures derived from an electroencephalogram (EEG) that are most suitable as markers of dysfunction have not been clearly established. A study was conducted to summarize and evaluate the statistical rigor of evidence on the overall utility of qEEG as an mTBI detection tool. The analysis evaluated qEEG measures/parameters that may be most suitable as fieldable diagnostic tools, identified other types of EEG measures and analysis methods of promise, recommended specific measures and analysis methods for further development as mTBI detection tools, identified research gaps in the field, and recommended future research and development thrust areas. The qEEG study group formed the following conclusions: (1) Individual qEEG measures provide limited diagnostic utility for mTBI. However, many measures can be important features of qEEG discriminant functions, which do show significant promise as mTBI detection tools. (2) ERPs offer utility in mTBI detection. In fact, evidence indicates that ERPs can identify abnormalities in cases where EEGs alone are non-disclosing. (3) The standard mathematical procedures used in the characterization of mTBI EEGs should be expanded to incorporate newer methods of analysis including non-linear dynamical analysis, complexity measures, analysis of causal interactions, graph theory, and information dynamics. (4) Reports of high specificity in q

  11. Traumatic Brain Injury Detection Using Electrophysiological Methods

    PubMed Central

    Rapp, Paul E.; Keyser, David O.; Albano, Alfonso; Hernandez, Rene; Gibson, Douglas B.; Zambon, Robert A.; Hairston, W. David; Hughes, John D.; Krystal, Andrew; Nichols, Andrew S.

    2015-01-01

    Measuring neuronal activity with electrophysiological methods may be useful in detecting neurological dysfunctions, such as mild traumatic brain injury (mTBI). This approach may be particularly valuable for rapid detection in at-risk populations including military service members and athletes. Electrophysiological methods, such as quantitative electroencephalography (qEEG) and recording event-related potentials (ERPs) may be promising; however, the field is nascent and significant controversy exists on the efficacy and accuracy of the approaches as diagnostic tools. For example, the specific measures derived from an electroencephalogram (EEG) that are most suitable as markers of dysfunction have not been clearly established. A study was conducted to summarize and evaluate the statistical rigor of evidence on the overall utility of qEEG as an mTBI detection tool. The analysis evaluated qEEG measures/parameters that may be most suitable as fieldable diagnostic tools, identified other types of EEG measures and analysis methods of promise, recommended specific measures and analysis methods for further development as mTBI detection tools, identified research gaps in the field, and recommended future research and development thrust areas. The qEEG study group formed the following conclusions: (1) Individual qEEG measures provide limited diagnostic utility for mTBI. However, many measures can be important features of qEEG discriminant functions, which do show significant promise as mTBI detection tools. (2) ERPs offer utility in mTBI detection. In fact, evidence indicates that ERPs can identify abnormalities in cases where EEGs alone are non-disclosing. (3) The standard mathematical procedures used in the characterization of mTBI EEGs should be expanded to incorporate newer methods of analysis including non-linear dynamical analysis, complexity measures, analysis of causal interactions, graph theory, and information dynamics. (4) Reports of high specificity in q

  12. Methods and Instruments for Fast Neutron Detection

    SciTech Connect

    Jordan, David V.; Reeder, Paul L.; Cooper, Matthew W.; McCormick, Kathleen R.; Peurrung, Anthony J.; Warren, Glen A.

    2005-05-01

    Pacific Northwest National Laboratory evaluated the performance of a large-area (~0.7 m2) plastic scintillator time-of-flight (TOF) sensor for direct detection of fast neutrons. This type of sensor is a readily area-scalable technology that provides broad-area geometrical coverage at a reasonably low cost. It can yield intrinsic detection efficiencies that compare favorably with moderator-based detection methods. The timing resolution achievable should permit substantially more precise time windowing of return neutron flux than would otherwise be possible with moderated detectors. The energy-deposition threshold imposed on each scintillator contributing to the event-definition trigger in a TOF system can be set to blind the sensor to direct emission from the neutron generator. The primary technical challenge addressed in the project was to understand the capabilities of a neutron TOF sensor in the limit of large scintillator area and small scintillator separation, a size regime in which the neutral particle’s flight path between the two scintillators is not tightly constrained.

  13. TLC bioautographic method for detecting lipase inhibitors.

    PubMed

    Hassan, Abdel Moniem Sadek

    2012-01-01

    Bioautographic assays using TLC play an important role in the search for active compounds from plants. A TLC bioautographic assay has previously been established for the detection of acetylcholinesterase inhibitors but not for lipases. Development of a TLC bioautographic method for detecting lipase inhibitors in plant extracts. After migration of the plant extracts, the TLC plate was sprayed with α-naphtyl acetate and enzyme solutions before incubation at 37°C for 20 min. Finally, the solution of Fast Blue B salt was sprayed onto the TLC plate giving a purple background colouration. Lipase inhibitors were visualised as white spots on the TLC plates. Orlistat (a known lipase inhibitor) inhibited lipase down to 0.01 µg. Methanolic extracts of Camellia sinensis (L.) kuntz and Rosmarinus officinalis L after migration on TLC gave enzymatic inhibition when applied in amounts of 82 and 56 µg, respectively. On the other hand the methanolic extract of Morus alba leaves did not exhibit any lipase inhibitory activity. The screening test was able to detect lipase inhibition by pure reference substances and by compounds present in complex matrices, such as plant extracts. Copyright © 2011 John Wiley & Sons, Ltd.

  14. Molecular detection methods of human papillomavirus (HPV).

    PubMed

    Zaravinos, Apostolos; Mammas, Ioannis N; Sourvinos, George; Spandidos, Demetrios A

    2009-01-01

    Human papillomavirus (HPV) testing can identify women at risk of cervical cancer. Currently, molecular detection methods are the gold standard for identification of HPV. The three categories of molecular assays that are available are based on the detection of HPV DNA and include (1) non-amplified hybridization assays, such as Southern transfer hybridization (STH), dot blot hybridization (DB) and in situ hybridization (ISH); (2) signal amplified hybridization assays, such as hybrid capture assays (HC2); (3) target amplification assays, such as polymerase chain reaction (PCR) and in situ PCR. STH requires large amounts of DNA, is laborious and not reproducible, while ISH has only moderate sensitivity for HPV. The sensitivity of the HC2 assay is similar to that of PCR-based assays, with high sensitivity being achieved by signal rather than target amplification. PCR-based detection is both highly sensitive and specific. Since PCR can be performed on very small amounts of DNA, it is ideal for use on specimens with low DNA content. In the future, with the advance of technology, viral DNA extraction and amplification systems will become more rapid, more sensitive, and more automated.

  15. Radiation sensitive area detection device and method

    NASA Technical Reports Server (NTRS)

    Carter, Daniel C. (Inventor); Hecht, Diana L. (Inventor); Witherow, William K. (Inventor)

    1991-01-01

    A radiation sensitive area detection device for use in conjunction with an X ray, ultraviolet or other radiation source is provided which comprises a phosphor containing film which releases a stored diffraction pattern image in response to incoming light or other electromagnetic wave. A light source such as a helium-neon laser, an optical fiber capable of directing light from the laser source onto the phosphor film and also capable of channelling the fluoresced light from the phosphor film to an integrating sphere which directs the light to a signal processing means including a light receiving means such as a photomultiplier tube. The signal processing means allows translation of the fluoresced light in order to detect the original pattern caused by the diffraction of the radiation by the original sample. The optical fiber is retained directly in front of the phosphor screen by a thin metal holder which moves up and down across the phosphor screen and which features a replaceable pinhole which allows easy adjustment of the resolution of the light projected onto the phosphor film. The device produces near real time images with high spatial resolution and without the distortion that accompanies prior art devices employing photomultiplier tubes. A method is also provided for carrying out radiation area detection using the device of the invention.

  16. Leak and Pipe Detection Method and System

    NASA Technical Reports Server (NTRS)

    Youngquist, Robert C. (Inventor)

    2003-01-01

    A method and system for locating leaks of conductive fluids from non-conductive pipes and other structures or for locat- ing non-conductive pipes or structures having conductive fluid contained therein, employ a charge generator to apply a time varying charge to the conductive fluid, and a capaci- tive type detector that can detect the variable charge that is induced in the fluid. The capacitive detector, which prefer- ably includes a handheld housing, employs a large conduc- tive pickup plate that is used to locate the pipe or leak by scanning the plate over the ground and detecting the induced charge that is generated when the plate comes in close proximity to the pipe or leak. If a leak is encountered, the resulting signal will appear over an area larger than expected for a buried pipe, assuming the leak provides an electrically conductive path between the flow and the wet surrounding ground. The detector uses any suitable type of indicator device, such as a pair of headphones that enable an operator to hear the detected signal as a chirping sound, for example.

  17. Lagrangian based methods for coherent structure detection

    SciTech Connect

    Allshouse, Michael R.; Peacock, Thomas

    2015-09-15

    There has been a proliferation in the development of Lagrangian analytical methods for detecting coherent structures in fluid flow transport, yielding a variety of qualitatively different approaches. We present a review of four approaches and demonstrate the utility of these methods via their application to the same sample analytic model, the canonical double-gyre flow, highlighting the pros and cons of each approach. Two of the methods, the geometric and probabilistic approaches, are well established and require velocity field data over the time interval of interest to identify particularly important material lines and surfaces, and influential regions, respectively. The other two approaches, implementing tools from cluster and braid theory, seek coherent structures based on limited trajectory data, attempting to partition the flow transport into distinct regions. All four of these approaches share the common trait that they are objective methods, meaning that their results do not depend on the frame of reference used. For each method, we also present a number of example applications ranging from blood flow and chemical reactions to ocean and atmospheric flows.

  18. Platelet antibody: review of detection methods

    SciTech Connect

    Schwartz, K.A.

    1988-10-01

    The driving force behind development of in vitro methods for platelet antibodies is identification of plasma factors causing platelet destruction. Early methods relied on measurement of platelet activation. Current methods are more specific and use a purified antibody against immunoglobulin or complement, which is usually labeled with /sup 125/I or tagged with an enzyme or fluorescein. Comparisons of quantitation of platelet-associated IgG show wide variability between different methods. The disparate results can be related both to differences in binding of secondary antibodies to immunoglobulin in solution compared to immunoglobulins attached to platelets and to the improper assumption that the binding ratio between the secondary detecting and primary antiplatelet antibody is one. Most assays can 1) identify neonatal isoimmune thrombocytopenia and posttransfusion purpura, 2) help to differentiate between immune and nonimmune thrombocytopenias, 3) help to sort out the offending drug when drug-induced thrombocytopenia is suspected, and 4) identify platelet alloantibodies and potential platelet donors via a cross match assay for refractory patients. However, the advantages of quantitative assays over qualitative methods with respect to predictions of patients clinical course and response to different treatments remain to be investigated. 61 references.

  19. Battery control and fault detection method

    SciTech Connect

    Bishop, W.S.

    1984-07-11

    This is a method for control, fault detection, fault isolation, and state-of-health monitoring of batteries and battery arrays. The method consists of measuring all of the battery, well, or cell group voltages, using statistics to determine a mean voltage and a standard deviation voltage, then comparing all of the measured voltages to the mean voltage. If the measured voltage deviates from the mean voltage by an arbitrary amount (number of standard deviations) corrective action can be implemented or an alarm signal given. The measurements need to be made rapidly enough to eliminate battery or cell voltage changes due to state of charge or temperature changes and, in most cases, require a computerized data collection/reduction system. Absolute high and/or low voltage limits can be included to prevent catastrophic events. The concept can be expanded to include similar temperature, pressure and/or battery current measurements in an array.

  20. Method and system for detecting explosives

    DOEpatents

    Reber, Edward L.; Jewell, James K.; Rohde, Kenneth W.; Seabury, Edward H.; Blackwood, Larry G.; Edwards, Andrew J.; Derr, Kurt W.

    2009-03-10

    A method of detecting explosives in a vehicle includes providing a first rack on one side of the vehicle, the rack including a neutron generator and a plurality of gamma ray detectors; providing a second rack on another side of the vehicle, the second rack including a neutron generator and a plurality of gamma ray detectors; providing a control system, remote from the first and second racks, coupled to the neutron generators and gamma ray detectors; using the control system, causing the neutron generators to generate neutrons; and performing gamma ray spectroscopy on spectra read by the gamma ray detectors to look for a signature indicative of presence of an explosive. Various apparatus and other methods are also provided.

  1. Discriminant methods for radar detection of hail

    NASA Astrophysics Data System (ADS)

    López, L.; Sánchez, J. L.

    A number of tools are available today - and more are currently being developed - to discriminate, within a particular storm, areas with hail precipitation using data provided by conventional meteorological radar systems. However, at a supraregional level most of the methods that have traditionally been employed to identify hailstorms often obtain ambiguous results. On the other hand, many currently available systems for data extraction and processing make it relatively easy to calculate a large number of variables derived from radar parameters for each storm analyzed and at different stages in its development. The questions are now: is it possible to select and/or classify these variables according to their ability to discriminate hailstorms from non-hail storms? And if so, would the combination of several of these variables enable us to develop new and improved discriminating tools? These questions have prompted the use of mathematical methods for discrimination, such as logistic regression and linear discriminant analysis. In both models the stepwise method was used to construct the mathematical equation automatically. Data from a C-band radar system installed in the NW of the Iberian Peninsula were used to set up the two models. The two models share a number of variables (VIL, maximum reflectivity, height of the maximum reflectivity and ddBZ_max/dt.), but the discriminant model makes use additionally of the top and the tilt of the storm. The results have been assessed not only in terms of the precision indices (the models have a probability of detection of 84.9% and 86.8%, respectively), but also with respect to their accuracy, sufficiency relation, resolution and discrimination. Finally, the logistic model has been calibrated for S-band radar systems. The results show a very satisfactory probability of detection, demonstrating that these methods may also be effective in this type of system.

  2. New method to detect caries via fluorescence

    NASA Astrophysics Data System (ADS)

    Eberhart, J.; Frentzen, M.; Thoms, M.

    2007-07-01

    Caries, a common and widespread infectious disease, has to be detected as early as possible. Based on the need for an easy and handy tool for preventing invasive treatment a new fluorescence camera system has been developed. Using this camera the so-called porphyrins, metabolic products of oral pathogenic bacteria can be visualized. Thereby fluorophores are excited at a wavelength of 405nm by the built-in GaN-LEDs. Healthy and diseased dental hard tissues fluoresce in the green and in the red spectral range, respectively, thus allowing differentiation by coulor. To prove the reliability of this fluorescence camera system, freshly extracted teeth were examined. Three different methods of analysis were verified and compared to give information about the lesions (sensitivity & selectivity): The extent of the fluorescence area, the integral of the red/green ratio of the lesion and the maximum red/green ratio in the area of interest. Histological sections of the teeth served as reference. In addition, the camera was compared to a tip probe sensor already available on the market. In total, our results show that regarding the three different algorithms of analysis, the maximum of the red/green ratio is a preferential method to evaluate carious lesions. Sound tissue, enamel caries and dentin caries can be clearly distinguished. The new fluorescence camera is a handy, efficient and fast device in order to detect lesions and seems to be superior to the tip probe sensor regarding the positioning. Further studies are required.

  3. Diagnostic methods for detection of bone metastases.

    PubMed

    Łukaszewski, Bartosz; Nazar, Jerzy; Goch, Maciej; Łukaszewska, Marta; Stępiński, Adrian; Jurczyk, Mieczysława U

    2017-01-01

    Skeletal metastases are severe complications in the course of cancer, and they indicate a worse prognosis. The use of modern imaging techniques allows rapid diagnosis of bone metastases. Properly selected diagnostic imaging (scintigraphy, positron emission tomography, whole body MRI) allows us to evaluate the number of metastatic foci in the skeletal system. Complementary imaging examinations (X-ray, computed tomography, magnetic resonance imaging) determine the extent of metastasis and its character: osteolytic, osteoblast, mixed). Hypercalcaemia is a symptom of low specificity for metastatic bone disease (a result of osteolysis); nevertheless, it is a significant complication in oncological treatment and worsens the prognosis of the patient. A biopsy is the final stage of the diagnostic process, which allows us to assess cell and tissue changes. Guided biopsies are performed under the control of musculoskeletal imaging methods (CT, MRI) and they are the most promising tools in bone metastases diagnosis. The development of guided biopsy techniques has led to the conclusion that they should be standard in diagnosing bone metastases. Liquid biopsy (LB) seems to be the most promising diagnostic method for detection of bone metastases. LB based on tumour-specific DNA mutation gives an opportunity for early detection and assessment of the molecular heterogeneity of the overall disease.

  4. Methods for detecting teratogenic agents in man.

    PubMed Central

    Shepard, T H; Miller, J R

    1976-01-01

    At a multidiscipline international meeting sponsored by L'Institut de la Vie held at Guadeloupe in January 1974, current methods for detecting teratogenic agents were outlined and discussed. Recommendations of the participants of the conference were: recognize the limitations of the present defenses against teratogenic agents; educate the public and medical profession about the known human teratogenic agents; select for animal teratogenicity screening among new and existing agents by emphasizing substances to which the entire population will be exposed, agents to which pregnant women are exposed, viruses which are found to persist in the human fetus, and agents which have become suspect from clinical experience; recognize that nearly all compounds have a fetotoxic dose but that this does not imply teratogenicity; encourage the development of new, quick in vitro testing methods for detecting teratogenic agents; monitor for sudden increases in the frequency of specific malformations in newborn infants and in aborted fetuses; assure that expert multidiscipline committees are available to evaluate the threat when suspected teratogens are reported; improve teratology information storage and retrieval systems by record linkage of clinical data, linkage between computer systems, and universal identifier system for chemical compounds and congenical malformations; foster the exchange of data, particularly those held by the pharmaceutical industry. PMID:1269501

  5. DEVELOPMENT OF MOLECULAR METHODS TO DETECT ...

    EPA Pesticide Factsheets

    A large number of human enteric viruses are known to cause gastrointestinal illness and waterborne outbreaks. Many of these are emerging viruses that do not grow or grow poorly in cell culture and so molecular detectoin methods based on the polymerase chain reaction (PCR) are being developed. Current studies focus on detecting two virus groups, the caliciviruses and the hepatitis E virus strains, both of which have been found to cause significant outbraks via contaminated drinking water. Once developed, these methods will be used to collect occurrence data for risk assessment studies. Develop sensitive techniques to detect and identify emerging human waterborne pathogenic viruses and viruses on the CCL.Determine effectiveness of viral indicators to measure microbial quality in water matrices.Support activities: (a) culture and distribution of mammalian cells for Agency and scientific community research needs, (b) provide operator expertise for research requiring confocal and electron microscopy, (c) glassware cleaning, sterilization and biological waste disposal for the Cincinnati EPA facility, (d) operation of infectious pathogenic suite, (e) maintenance of walk-in constant temperature rooms and (f) provide Giardia cysts.

  6. Method and apparatus for vapor detection

    NASA Technical Reports Server (NTRS)

    Lerner, Melvin (Inventor); Hood, Lyal V. (Inventor); Rommel, Marjorie A. (Inventor); Pettitt, Bruce C. (Inventor); Erikson, Charles M. (Inventor)

    1980-01-01

    The method disclosed herein may be practiced by passing the vapors to be sampled along a path with halogen vapor, preferably chlorine vapor, heating the mixed vapors to halogenate those of the sampled vapors subject to halogenation, removing unreacted halogen vapor, and then sensing the vapors for organic halogenated compounds. The apparatus disclosed herein comprises means for flowing the vapors, both sample and halogen vapors, into a common path, means for heating the mixed vapors to effect the halogenation reaction, means for removing unreacted halogen vapor, and a sensing device for sensing halogenated compounds. By such a method and means, the vapors of low molecular weight hydrocarbons, ketones and alcohols, when present, such as methane, ethane, acetone, ethanol, and the like are converted, at least in part, to halogenated compounds, then the excess halogen removed or trapped, and the resultant vapors of the halogenated compounds sensed or detected. The system is highly sensitive. For example, acetone in a concentration of 30 parts per billion (volume) is readily detected.

  7. Nucleic acid detection system and method for detecting influenza

    DOEpatents

    Cai, Hong; Song, Jian

    2015-03-17

    The invention provides a rapid, sensitive and specific nucleic acid detection system which utilizes isothermal nucleic acid amplification in combination with a lateral flow chromatographic device, or DNA dipstick, for DNA-hybridization detection. The system of the invention requires no complex instrumentation or electronic hardware, and provides a low cost nucleic acid detection system suitable for highly sensitive pathogen detection. Hybridization to single-stranded DNA amplification products using the system of the invention provides a sensitive and specific means by which assays can be multiplexed for the detection of multiple target sequences.

  8. Odour detection methods: olfactometry and chemical sensors.

    PubMed

    Brattoli, Magda; de Gennaro, Gianluigi; de Pinto, Valentina; Loiotile, Annamaria Demarinis; Lovascio, Sara; Penza, Michele

    2011-01-01

    The complexity of the odours issue arises from the sensory nature of smell. From the evolutionary point of view olfaction is one of the oldest senses, allowing for seeking food, recognizing danger or communication: human olfaction is a protective sense as it allows the detection of potential illnesses or infections by taking into account the odour pleasantness/unpleasantness. Odours are mixtures of light and small molecules that, coming in contact with various human sensory systems, also at very low concentrations in the inhaled air, are able to stimulate an anatomical response: the experienced perception is the odour. Odour assessment is a key point in some industrial production processes (i.e., food, beverages, etc.) and it is acquiring steady importance in unusual technological fields (i.e., indoor air quality); this issue mainly concerns the environmental impact of various industrial activities (i.e., tanneries, refineries, slaughterhouses, distilleries, civil and industrial wastewater treatment plants, landfills and composting plants) as sources of olfactory nuisances, the top air pollution complaint. Although the human olfactory system is still regarded as the most important and effective "analytical instrument" for odour evaluation, the demand for more objective analytical methods, along with the discovery of materials with chemo-electronic properties, has boosted the development of sensor-based machine olfaction potentially imitating the biological system. This review examines the state of the art of both human and instrumental sensing currently used for the detection of odours. The olfactometric techniques employing a panel of trained experts are discussed and the strong and weak points of odour assessment through human detection are highlighted. The main features and the working principles of modern electronic noses (E-Noses) are then described, focusing on their better performances for environmental analysis. Odour emission monitoring carried out through

  9. Odour Detection Methods: Olfactometry and Chemical Sensors

    PubMed Central

    Brattoli, Magda; de Gennaro, Gianluigi; de Pinto, Valentina; Loiotile, Annamaria Demarinis; Lovascio, Sara; Penza, Michele

    2011-01-01

    The complexity of the odours issue arises from the sensory nature of smell. From the evolutionary point of view olfaction is one of the oldest senses, allowing for seeking food, recognizing danger or communication: human olfaction is a protective sense as it allows the detection of potential illnesses or infections by taking into account the odour pleasantness/unpleasantness. Odours are mixtures of light and small molecules that, coming in contact with various human sensory systems, also at very low concentrations in the inhaled air, are able to stimulate an anatomical response: the experienced perception is the odour. Odour assessment is a key point in some industrial production processes (i.e., food, beverages, etc.) and it is acquiring steady importance in unusual technological fields (i.e., indoor air quality); this issue mainly concerns the environmental impact of various industrial activities (i.e., tanneries, refineries, slaughterhouses, distilleries, civil and industrial wastewater treatment plants, landfills and composting plants) as sources of olfactory nuisances, the top air pollution complaint. Although the human olfactory system is still regarded as the most important and effective “analytical instrument” for odour evaluation, the demand for more objective analytical methods, along with the discovery of materials with chemo-electronic properties, has boosted the development of sensor-based machine olfaction potentially imitating the biological system. This review examines the state of the art of both human and instrumental sensing currently used for the detection of odours. The olfactometric techniques employing a panel of trained experts are discussed and the strong and weak points of odour assessment through human detection are highlighted. The main features and the working principles of modern electronic noses (E-Noses) are then described, focusing on their better performances for environmental analysis. Odour emission monitoring carried out

  10. Hazard Detection Methods for Lunar Landing

    NASA Technical Reports Server (NTRS)

    Brady, Tye; Zimpfer, Doug; Robertson, Edward; Epp, Chirold; Paschall, Stephen

    2009-01-01

    The methods and experiences from the Apollo Program are fundamental building blocks for the development of lunar landing strategies for the Constellation Program. Each of the six lunar landing Apollo missions landed under near ideal lighting conditions. The astronauts visually performed terrain relative navigation while looking out of windows, and were greatly aided by external communication and well lit scenes. As the LM approached the landing site, the astronauts performed visual hazard detection and avoidance, also under near-ideal lighting conditions. The astronauts were looking out of the windows trying to the best of their ability to avoid rocks, slopes, and craters and find a safe landing location. NASA has expressed a desire for global lunar access for both crewed and robotic sortie lunar exploration missions (Cook, 2007) (Dale, 2006). Early NASA architecture studies have identified the lunar poles as desirable locations for early lunar missions. These polar missions have less than ideal lighting conditions and will significantly affect the way a crewed vehicle plans to land at such locales. Consequently, a variety of hazard identification methods should be considered for use by the crew to ensure a high degree of safety. This paper discusses such identification methods applicable to the poorly lit polar lunar environment, better ensuring global access for the soon to be designed Lunar Lander Vehicle (LLV).

  11. Hazard Detection Methods for Lunar Landing

    NASA Technical Reports Server (NTRS)

    Brady, Tye; Zimpfer, Doug; Robertson, Edward; Epp, Chirold; Paschall, Stephen

    2009-01-01

    The methods and experiences from the Apollo Program are fundamental building blocks for the development of lunar landing strategies for the Constellation Program. Each of the six lunar landing Apollo missions landed under near ideal lighting conditions. The astronauts visually performed terrain relative navigation while looking out of windows, and were greatly aided by external communication and well lit scenes. As the LM approached the landing site, the astronauts performed visual hazard detection and avoidance, also under near-ideal lighting conditions. The astronauts were looking out of the windows trying to the best of their ability to avoid rocks, slopes, and craters and find a safe landing location. NASA has expressed a desire for global lunar access for both crewed and robotic sortie lunar exploration missions (Cook, 2007) (Dale, 2006). Early NASA architecture studies have identified the lunar poles as desirable locations for early lunar missions. These polar missions have less than ideal lighting conditions and will significantly affect the way a crewed vehicle plans to land at such locales. Consequently, a variety of hazard identification methods should be considered for use by the crew to ensure a high degree of safety. This paper discusses such identification methods applicable to the poorly lit polar lunar environment, better ensuring global access for the soon to be designed Lunar Lander Vehicle (LLV).

  12. Method and system for turbomachinery surge detection

    DOEpatents

    Faymon, David K.; Mays, Darrell C.; Xiong, Yufei

    2004-11-23

    A method and system for surge detection within a gas turbine engine, comprises: measuring the compressor discharge pressure (CDP) of the gas turbine over a period of time; determining a time derivative (CDP.sub.D ) of the measured (CDP) correcting the CDP.sub.D for altitude, (CDP.sub.DCOR); estimating a short-term average of CDP.sub.DCOR.sup.2 ; estimating a short-term average of CDP.sub.DCOR ; and determining a short-term variance of corrected CDP rate of change (CDP.sub.roc) based upon the short-term average of CDP.sub.DCOR and the short-term average of CDP.sub.DCOR.sup.2. The method and system then compares the short-term variance of corrected CDP rate of change with a pre-determined threshold (CDP.sub.proc) and signals an output when CDP.sub.roc >CDP.sub.proc. The method and system provides a signal of a surge within the gas turbine engine when CDP.sub.roc remains>CDP.sub.proc for pre-determined period of time.

  13. Solar cell anomaly detection method and apparatus

    NASA Technical Reports Server (NTRS)

    Miller, Emmett L. (Inventor); Shumka, Alex (Inventor); Gauthier, Michael K. (Inventor)

    1981-01-01

    A method is provided for detecting cracks and other imperfections in a solar cell, which includes scanning a narrow light beam back and forth across the cell in a raster pattern, while monitoring the electrical output of the cell to find locations where the electrical output varies significantly. The electrical output can be monitored on a television type screen containing a raster pattern with each point on the screen corresponding to a point on the solar cell surface, and with the brightness of each point on the screen corresponding to the electrical output from the cell which was produced when the light beam was at the corresponding point on the cell. The technique can be utilized to scan a large array of interconnected solar cells, to determine which ones are defective.

  14. Liquid chromatography detection unit, system, and method

    SciTech Connect

    Derenzo, Stephen E.; Moses, William W.

    2015-10-27

    An embodiment of a liquid chromatography detection unit includes a fluid channel and a radiation detector. The radiation detector is operable to image a distribution of a radiolabeled compound as the distribution travels along the fluid channel. An embodiment of a liquid chromatography system includes an injector, a separation column, and a radiation detector. The injector is operable to inject a sample that includes a radiolabeled compound into a solvent stream. The position sensitive radiation detector is operable to image a distribution of the radiolabeled compound as the distribution travels along a fluid channel. An embodiment of a method of liquid chromatography includes injecting a sample that comprises radiolabeled compounds into a solvent. The radiolabeled compounds are then separated. A position sensitive radiation detector is employed to image distributions of the radiolabeled compounds as the radiolabeled compounds travel along a fluid channel.

  15. SKM-SNP: SNP markers detection method.

    PubMed

    Liu, Yang; Li, Mark; Cheung, Yiu M; Sham, Pak C; Ng, Michael K

    2010-04-01

    SKM-SNP, SNP markers detection program, is proposed to identify a set of relevant SNPs for the association between a disease and multiple marker genotypes. We employ a subspace categorical clustering algorithm to compute a weight for each SNP in the group of patient samples and the group of normal samples, and use the weights to identify the subsets of relevant SNPs that categorize these two groups. The experiments on both Schizophrenia and Parkinson Disease data sets containing genome-wide SNPs are reported to demonstrate the program. Results indicate that our method can find some relevant SNPs that categorize the disease samples. The online SKM-SNP program is available at http://www.math.hkbu.edu.hk/~mng/SKM-SNP/SKM-SNP.html.

  16. Material degradation detection by magnetic method

    SciTech Connect

    Yamaguchi, A.; Maeda, N.; Sugibayashi, T.

    1995-08-01

    To be able to evaluate the life of nuclear power plant becomes inevitable as the plant operating period extends. So, magnetic methods using Barkhausen noise (BHN) and B-H curve were applied to detect the degradation by fatigue and thermal aging. Low alloy steel (SA 508 cl.2) was fatigued, and duplex stainless steel (SCS 14A) was aged at 400 C. For the degradation by thermal aging, BHN and B-H curve were measured and good correlations between magnetic properties and aging time were obtained. For fatigue, BHN was measured at predetermined loading cycles and, at each predetermined cycle, the effect of stress or strain condition in the measurement was evaluated. The results showed that BHN was affected by the stress or strain condition in the measurement, the cause of which seemed to be the change of internal stress condition, and by identifying the measuring condition, good correlation between BHN and fatigue damage was obtained.

  17. Systems and methods for detecting neutrons

    DOEpatents

    Bross, Alan D.; Mellott, Kerry L.; Pla-Dalmau, Anna

    2005-08-09

    Systems and methods for detecting neutrons. One or more neutron-sensitive scintillators can be configured from a plurality of nano-sized particles, dopants and an extruded plastic material, such as polystyrene. The nano-sized particles can be compounded into the extruded plastic material with at least one dopant that permits the plastic material to scintillate. One or more plastic light collectors can be associated with a neutron-sensitive scintillator, such that the plastic light collector includes a central hole thereof. A wavelength-shifting fiber can then be located within the hole. The wavelength shifting (WLS) fiber absorbs scintillation light having a wavelength thereof and re-emits the light at a longer wavelength.

  18. Detecting ATP release by a biosensor method.

    PubMed

    Hayashi, Seiji; Hazama, Akihiro; Dutta, Amal K; Sabirov, Ravshan Z; Okada, Yasunobu

    2004-11-09

    Cells release adenosine 5'-triphosphate (ATP) into the extracellular space in response to various stimuli. This released ATP plays an important physiological role in cell-to-cell signal transduction. The bulk ATP concentration can be detected using a conventional luciferin-luciferase assay. However, the ATP concentration in the vicinity of the cell surface is often different from the bulk concentration because of its rapid degradation by ecto-ATPases and because of delayed diffusion due to unstirred layer effects. Here, we describe a simple biosensor method to measure the local ATP concentration on the cell surface in real time. The method is based on the ATP-dependent opening of ligand-gated cation channels of purinergic P2X receptors expressed in undifferentiated pheochromocytoma (PC12) cells or in human embryonic kidney 293 (HEK293) cells stably transfected with recombinant P2X2 purinergic receptors. Under the whole-cell configuration of patch-clamp, a sensor PC12 cell or HEK293 is positioned within the proximity of a target cell, and the P2X-mediated currents induced by ATP released from a given site on the target cell surface is measured. The ATP release is quantified by a calibration procedure utilizing local puff applications of ATP at preset concentrations.

  19. Sensor And Method For Detecting A Superstrate

    NASA Technical Reports Server (NTRS)

    Arndt, G. Dickey (Inventor); Cari, James R. (Inventor); Ngo, Phong H. (Inventor); Fink, Patrick W. (Inventor); Siekierski, James D. (Inventor)

    2006-01-01

    Method and apparatus are provided for determining a superstrate on or near a sensor, e.g., for detecting the presence of an ice superstrate on an airplane wing or a road. In one preferred embodiment, multiple measurement cells are disposed along a transmission line. While the present invention is operable with different types of transmission lines, construction details for a presently preferred coplanar waveguide and a microstrip waveguide are disclosed. A computer simulation is provided as part of the invention for predicting results of a simulated superstrate detector system. The measurement cells may be physically partitioned, nonphysically partitioned with software or firmware, or include a combination of different types of partitions. In one embodiment, a plurality of transmission lines are utilized wherein each transmission line includes a plurality of measurement cells. The plurality of transmission lines may be multiplexed with the signal from each transmission line being applied to the same phase detector. In one embodiment, an inverse problem method is applied to determine the superstrate dielectric for a transmission line with multiple measurement cells.

  20. Method for detecting viruses in aerosols.

    PubMed Central

    Wallis, C; Melnick, J L; Rao, V C; Sox, T E

    1985-01-01

    A simple method with poliovirus as the model was developed for recovering human enteric viruses from aerosols. Filterite filters (pore size, 0.45 micron; Filterite Corp., Timonium, Md.) moistened with glycine buffer (pH 3.5) were used for adsorbing the aerosolized virus. No virus passed the filter, even with air flow rates of 100 liters/min. Virus recovery from the filter was achieved by rapid elution with 800 ml of glycine buffer, pH 10. The virus in the primary eluate was reconcentrated by adjusting the pH to 3.5, adding AlCl3 to 0.0005 M, collecting the virus on a 0.25-micron-pore Filerite disk (diameter, 25 mm) and and eluting with 6 ml of buffer, pH 10. With this method, virus could be detected regularly in aerosols produced by flushing when 3 X 10(8) PFU of poliovirus were present in the toilet bowl. Poliovirus-containing fecal material from two of four infants who had recently received oral polio vaccine also yielded virus in the aerosols when feces containing 2.4 X 10(7) to 4.5 X 10(7) PFU of virus had been added to the toilet bowl. Persons infected with a variety of natural enteric viruses are known to excrete this amount of virus in their daily stools. Images PMID:3004329

  1. Barriers on Breast Cancer Early Detection Methods

    PubMed Central

    Aksoy, Yasemin Erkal; Turfan, Esin Çeber; Sert, Ebru; Mermer, Gülengül

    2015-01-01

    . Conclusion Barriers against implementation of breast cancer screening methods in women were related to level of education and lack of adequate information about breast cancer screening, and symptoms of breast cancer. Women’s lack of information about signs, symptoms and treatment in the early stages of breast cancer needs to be eliminated. Health care providers may have a key role in increasing breast cancer early detection rates.

  2. Radio frequency detection assembly and method for detecting radio frequencies

    DOEpatents

    Cown, Steven H.; Derr, Kurt Warren

    2010-03-16

    A radio frequency detection assembly is described and which includes a radio frequency detector which detects a radio frequency emission produced by a radio frequency emitter from a given location which is remote relative to the radio frequency detector; a location assembly electrically coupled with the radio frequency detector and which is operable to estimate the location of the radio frequency emitter from the radio frequency emission which has been received; and a radio frequency transmitter electrically coupled with the radio frequency detector and the location assembly, and which transmits a radio frequency signal which reports the presence of the radio frequency emitter.

  3. Surface-crack detection by microwave methods

    NASA Technical Reports Server (NTRS)

    Feinstein, L.; Hruby, R.

    1967-01-01

    Microwave surface-crack detection system examines metallic surfaces with a noncontacting probe. The change in the microwave signal reflected from the surface under investigation is an indication of the existence of surface flaws. This technique can detect flaws and scratches as small as 100 microinches.

  4. A Generalized Machine Fault Detection Method Using Unified Change Detection

    DTIC Science & Technology

    2014-10-02

    Defence Science and Technology Organisation, Melbourne , VIC 3207, Australia Wenyi.Wang@dsto.defence.gov.au David.Forrester@dsto.defence.gov.au...International Conference of Maintenance Societies, May 2007, Melbourne , Australia. Blunt, D.M and Keller, J.A. (2006). Detection of a fatigue crack in a UH...in RAN Sea King’s. Vertiflite Conference (AIAC12), 13-17 March 2007, Melbourne , Australia. Hancock, K.M. and Zhang, Q. (2006). A Hybrid Approach to

  5. DNA Nanostructure-based Interfacial engineering for PCR-free ultrasensitive electrochemical analysis of microRNA

    NASA Astrophysics Data System (ADS)

    Wen, Yanli; Pei, Hao; Shen, Ye; Xi, Junjie; Lin, Meihua; Lu, Na; Shen, Xizhong; Li, Jiong; Fan, Chunhai

    2012-11-01

    MicroRNAs (miRNAs) have been identified as promising cancer biomarkers due to their stable presence in serum. As an alternative to PCR-based homogenous assays, surface-based electrochemical biosensors offer great opportunities for low-cost, point-of-care tests (POCTs) of disease-associated miRNAs. Nevertheless, the sensitivity of miRNA sensors is often limited by mass transport and crowding effects at the water-electrode interface. To address such challenges, we herein report a DNA nanostructure-based interfacial engineering approach to enhance binding recognition at the gold electrode surface and drastically improve the detection sensitivity. By employing this novel strategy, we can directly detect as few as attomolar (<1, 000 copies) miRNAs with high single-base discrimination ability. Given that this ultrasensitive electrochemical miRNA sensor (EMRS) is highly reproducible and essentially free of prior target labeling and PCR amplification, we also demonstrate its application by analyzing miRNA expression levels in clinical samples from esophageal squamous cell carcinoma (ESCC) patients.

  6. System and method for detecting cells or components thereof

    DOEpatents

    Porter, Marc D.; Lipert, Robert J.; Doyle, Robert T.; Grubisha, Desiree S.; Rahman, Salma

    2009-01-06

    A system and method for detecting a detectably labeled cell or component thereof in a sample comprising one or more cells or components thereof, at least one cell or component thereof of which is detectably labeled with at least two detectable labels. In one embodiment, the method comprises: (i) introducing the sample into one or more flow cells of a flow cytometer, (ii) irradiating the sample with one or more light sources that are absorbed by the at least two detectable labels, the absorption of which is to be detected, and (iii) detecting simultaneously the absorption of light by the at least two detectable labels on the detectably labeled cell or component thereof with an array of photomultiplier tubes, which are operably linked to two or more filters that selectively transmit detectable emissions from the at least two detectable labels.

  7. Nuclear material detection apparatus and method

    DOEpatents

    Jones, James L.; Hoggan, Jerry M.; Harker, Yale D.; Yoon, Woo Y.; Johnson, Larry O.

    2006-11-28

    A device for detecting photonuclear-induced neutrons is described herein. One embodiment of the device may comprise a neutron detector and a detection circuit. The neutron detector may comprise a detector output. The detection circuit may be operatively connected to the detector output and may comprise an amplifier, a low-pass filter, and a high pass filter. The amplifier may comprise an amplifier input and an amplifier output. The amplifier input may be being operatively connected to the detector output. The low-pass filter may comprise a low-pass filter input and a low-pass filter output. The low-pass filter input may be operatively connected to the amplifier output. The high-pass filter may comprise a high-pass filter input and a high-pass filter output. The high-pass filter input may be operatively connected to the amplifier output.

  8. Source detection with the scaling index method.

    NASA Astrophysics Data System (ADS)

    Wiedemann, G.; Scheingraber, H.; Voges, W.

    The purpose of source detection algorithms in general is to distinguish between sources and non-significant background fluctuations. Most algorithms introduce an artificial partition of the event space by use of sliding windows. The procedure proposed here uses a natural partition given by the events themselves. The scaling index formalism assigns a scalar parameter to every event which can be classified by means of distribution theory as belonging to the background or to a source. No assumptions about the source geometry are necessary making the formalism most sensitive to the detection of extended irregular sources.

  9. Ultrasonic Methods for Human Motion Detection

    DTIC Science & Technology

    2006-10-01

    detectable values of Doppler shifts in reflected waves from a walking person at a distance of 1-18 meters on the test track. The horizontal red line...sensors in air,” IEEE Ultrasonic symposium, Proceedings, pp. 471-481 (1994). [11] http://www.nlectc.org/ perimetr /full2.htm [12] H.E. Bass and L.N Bolen

  10. Rapid Methods for the Detection of General Fecal Indicators

    EPA Science Inventory

    Specified that EPA should develop: appropriate and effective indicators for improving detection in a timely manner of pathogens in coastal waters appropriate, accurate, expeditious and cost-effective methods for the timely detection of pathogens in coastal waters

  11. Rapid Methods for the Detection of General Fecal Indicators

    EPA Science Inventory

    Specified that EPA should develop: appropriate and effective indicators for improving detection in a timely manner of pathogens in coastal waters appropriate, accurate, expeditious and cost-effective methods for the timely detection of pathogens in coastal waters

  12. A comparison of moving object detection methods for real-time moving object detection

    NASA Astrophysics Data System (ADS)

    Roshan, Aditya; Zhang, Yun

    2014-06-01

    Moving object detection has a wide variety of applications from traffic monitoring, site monitoring, automatic theft identification, face detection to military surveillance. Many methods have been developed across the globe for moving object detection, but it is very difficult to find one which can work globally in all situations and with different types of videos. The purpose of this paper is to evaluate existing moving object detection methods which can be implemented in software on a desktop or laptop, for real time object detection. There are several moving object detection methods noted in the literature, but few of them are suitable for real time moving object detection. Most of the methods which provide for real time movement are further limited by the number of objects and the scene complexity. This paper evaluates the four most commonly used moving object detection methods as background subtraction technique, Gaussian mixture model, wavelet based and optical flow based methods. The work is based on evaluation of these four moving object detection methods using two (2) different sets of cameras and two (2) different scenes. The moving object detection methods have been implemented using MatLab and results are compared based on completeness of detected objects, noise, light change sensitivity, processing time etc. After comparison, it is observed that optical flow based method took least processing time and successfully detected boundary of moving objects which also implies that it can be implemented for real-time moving object detection.

  13. Methods and systems for detection of radionuclides

    DOEpatents

    Coates, Jr., John T.; DeVol, Timothy A.

    2010-05-25

    Disclosed are materials and systems useful in determining the existence of radionuclides in an aqueous sample. The materials provide the dual function of both extraction and scintillation to the systems. The systems can be both portable and simple to use, and as such can beneficially be utilized to determine presence and optionally concentration of radionuclide contamination in an aqueous sample at any desired location and according to a relatively simple process without the necessity of complicated sample handling techniques. The disclosed systems include a one-step process, providing simultaneous extraction and detection capability, and a two-step process, providing a first extraction step that can be carried out in a remote field location, followed by a second detection step that can be carried out in a different location.

  14. Standardized Methods for Detection of Poliovirus Antibodies.

    PubMed

    Weldon, William C; Oberste, M Steven; Pallansch, Mark A

    2016-01-01

    Testing for neutralizing antibodies against polioviruses has been an established gold standard for assessing individual protection from disease, population immunity, vaccine efficacy studies, and other vaccine clinical trials. Detecting poliovirus specific IgM and IgA in sera and mucosal specimens has been proposed for evaluating the status of population mucosal immunity. More recently, there has been a renewed interest in using dried blood spot cards as a medium for sample collection to enhance surveillance of poliovirus immunity. Here, we describe the modified poliovirus microneutralization assay, poliovirus capture IgM and IgA ELISA assays, and dried blood spot polio serology procedures for the detection of antibodies against poliovirus serotypes 1, 2, and 3.

  15. Method of detecting and counting bacteria

    NASA Technical Reports Server (NTRS)

    Picciolo, G. L.; Chappelle, E. W. (Inventor)

    1976-01-01

    An improved method is provided for determining bacterial levels, especially in samples of aqueous physiological fluids. The method depends on the quantitative determination of bacterial adenosine triphosphate (ATP) in the presence of nonbacterial ATP. The bacterial ATP is released by cell rupture and is measured by an enzymatic bioluminescent assay. A concentration technique is included to make the method more sensitive. It is particularly useful where the fluid to be measured contains an unknown or low bacteria count.

  16. Method for detection of extremely low concentration

    DOEpatents

    Andresen, Brian D.; Miller, Fred S.

    2002-01-01

    An ultratrace detector system for hand-held gas chromatography having high sensitivity, for example, to emissions generated during production of weapons, biological compounds, drugs, etc. The detector system is insensitive to water, air, helium, argon, oxygen, and CO.sub.2. The detector system is basically composed of a hand-held capillary gas chromatography (GC), an insulated heated redox-chamber, a detection chamber, and a vapor trap. For example, the detector system may use gas phase redox reactions and spectral absorption of mercury vapor. The gas chromatograph initially separates compounds that percolate through a bed of heated mercuric oxide (HgO) in a silica--or other metal--aerogel material which acts as an insulator. Compounds easily oxidized by HgO liberate atomic mercury that subsequently pass through a detection chamber which includes a detector cell, such as quartz, that is illuminated with a 254 nm ultra-violet (UV) mercury discharge lamp which generates the exact mercury absorption bands that are used to detect the liberated mercury atoms. Atomic mercury strongly absorbs 254 nm energy is therefore a specific signal for reducing compounds eluting from the capillary GC, whereafter the atomic mercury is trapped for example, in a silicon-aerogel trap.

  17. Method for early detection of infectious mononucleosis

    DOEpatents

    Willard, K.E.

    1982-08-10

    Early detection of infectious mononucleosis is carried out using a sample of human blood by isolating and identifying the presence of Inmono proteins in the sample from a two-dimensional protein map with the proteins being characterized by having isoelectric banding as measured in urea of about -16 to -17 with respect to certain isoelectric point standards and molecular mass of about 70 to 75 K daltons as measured in the presence of sodium dodecylsulfate containing polyacrylamide gels, the presence of the Inmono proteins being correlated with the existence of infectious mononucleosis.

  18. System and method for detecting gas

    DOEpatents

    Chow, Oscar Ken; Moulthrop, Lawrence Clinton; Dreier, Ken Wayne; Miller, Jacob Andrew

    2010-03-16

    A system to detect a presence of a specific gas in a mixture of gaseous byproducts comprising moisture vapor is disclosed. The system includes an electrochemical cell, a transport to deliver the mixture of gaseous byproducts from the electrochemical cell, a gas sensor in fluid communication with the transport, the sensor responsive to a presence of the specific gas to generate a signal corresponding to a concentration of the specific gas, and a membrane to prevent transmission of liquid moisture, the membrane disposed between the transport and the gas sensor.

  19. Correlation studies on surface particle detection methods

    NASA Technical Reports Server (NTRS)

    Peterson, Ronald V.; White, James C.

    1988-01-01

    The accurate determination of dust levels on optical surfaces is necessary to assess sensor system performance. A comparison study was made on several particle measurement methods including those based on direct imaging and light scattering. The effectiveness of removing the particles from the surface prior to determining particle size distributions was also assessed. These studies revealed that some methods, especially those requiring particle removal before analysis, are subject to large systematic errors affecting particle size distributions. Thus, an understanding of the particle measurement methods employed is necessary before any surface cleanliness or obstruction value assignments are accepted as true representations of an optical surface contamination condition.

  20. Polarization sensitive optical coherence tomography detection method

    SciTech Connect

    Everett, M J; Sathyam, U S; Colston, B W; DaSilva, L B; Fried, D; Ragadio, J N; Featherstone, J D B

    1999-05-12

    This study demonstrates the potential of polarization sensitive optical coherence tomography (PS-OCT) for non-invasive in vivo detection and characterization of early, incipient caries lesions. PS-OCT generates cross-sectional images of biological tissue while measuring the effect of the tissue on the polarization state of incident light. Clear discrimination between regions of normal and demineralized enamel is first shown in PS-OCT images of bovine enamel blocks containing well-characterized artificial lesions. High-resolution, cross-sectional images of extracted human teeth are then generated that clearly discriminate between the normal and carious regions on both the smooth and occlusal surfaces. Regions of the teeth that appeared to be demineralized in the PS-OCT images were verified using histological thin sections examined under polarized light microscopy. The PS-OCT system discriminates between normal and carious regions by measuring the polarization state of the back-scattered 1310 nm light, which is affected by the state of demineralization of the enamel. Demineralization of enamel increases the scattereing coefficient, thus depolarizing the incident light. This study shows that PS-OCT has great potential for the detection, characterization, and monitoring of incipient caries lesions.

  1. Endotoxemia: methods of detection and clinical correlates.

    PubMed Central

    Hurley, J C

    1995-01-01

    As an assay for endotoxin, the Limulus amebocyte lysate assay has several desirable properties: sensitivity, specificity, and potential for adaptation to a quantitative format. Several modifications have been developed to enhance its potential for clinical application. The modifications that allow quantitative measurement of endotoxin and also improve its application to blood samples are described in this review. In fluids other than blood, the detection of endotoxin with the Limulus amebocyte lysate assay can be used as an aid to identify the presence of gram-negative bacteria, and the assay has established utility. With blood, however, there are a range of factors that interfere with the detection of endotoxemia and there are disparate views with respect to the diagnostic and prognostic significance of the test results. In general, the clinical significance of the finding of endotoxemia broadly parallels the frequency and importance of gram-negative sepsis in the patient groups studied and a decline in endotoxin levels accompanies clinical improvement. However, with therapies designed to reduce levels of endotoxin, or to antagonize its effects, it is unclear whether clinical improvement occurs as a consequence of changes in the levels of endotoxemia. PMID:7621402

  2. Marine Biotoxins: Occurrence, Toxicity, and Detection Methods

    NASA Astrophysics Data System (ADS)

    Asakawa, M.

    2017-04-01

    This review summarizes the role of marine organisms as vectors of marine biotoxins, and discusses the need for surveillance to protect public health and ensure the quality of seafood. I Paralytic shellfish poison (PSP) and PSP-bearing organisms-PSP is produced by toxic dinoflagellates species belonging to the genera Alexandrium, Gymnodinium, and Pyrodinium. Traditionally, PSP monitoring programs have only considered filter-feeding molluscs that concentrate these toxic algae, however, increasing attention is now being paid to higher-order predators that carry PSP, such as carnivorous gastropods and crustaceans. II. Tetrodotoxin (TTX) and TTX-bearing organisms - TTX is the most common natural marine toxin that causes food poisonings in Japan, and poses a serious public health risk. TTX was long believed to be present only in pufferfish. However, TTX was detected in the eggs of California newt Taricha torosa in 1964, and since then it has been detected in a wide variety of species belonging to several different phyla. In this study, the main toxic components in the highly toxic ribbon worm Cephalothrix simula and the greater blue-ringed octopus Hapalochlaena lunulata from Japan were purified and analysed.

  3. Abnormality degree detection method using negative potential field group detectors

    NASA Astrophysics Data System (ADS)

    Zhang, Hongli; Liu, Shulin; Li, Dong; Shi, Kunju; Wang, Bo; Cui, Jiqiang

    2015-09-01

    Online monitoring methods have been widely used in many major devices, however the normal and abnormal states of equipment are estimated mainly based on the monitoring results whether monitored parameters exceed the setting thresholds. Using these monitoring methods may cause serious false positive or false negative results. In order to precisely monitor the state of equipment, the problem of abnormality degree detection without fault sample is studied with a new detection method called negative potential field group detectors(NPFG-detectors). This method achieves the quantitative expression of abnormality degree and provides the better detection results compared with other methods. In the process of Iris data set simulation, the new algorithm obtains the successful results in abnormal detection. The detection rates for 3 types of Iris data set respectively reach 100%, 91.6%, and 95.24% with 50% training samples. The problem of Bearing abnormality degree detection via an abnormality degree curve is successfully solved.

  4. Detection methods and performance criteria for genetically modified organisms.

    PubMed

    Bertheau, Yves; Diolez, Annick; Kobilinsky, André; Magin, Kimberly

    2002-01-01

    Detection methods for genetically modified organisms (GMOs) are necessary for many applications, from seed purity assessment to compliance of food labeling in several countries. Numerous analytical methods are currently used or under development to support these needs. The currently used methods are bioassays and protein- and DNA-based detection protocols. To avoid discrepancy of results between such largely different methods and, for instance, the potential resulting legal actions, compatibility of the methods is urgently needed. Performance criteria of methods allow evaluation against a common standard. The more-common performance criteria for detection methods are precision, accuracy, sensitivity, and specificity, which together specifically address other terms used to describe the performance of a method, such as applicability, selectivity, calibration, trueness, precision, recovery, operating range, limit of quantitation, limit of detection, and ruggedness. Performance criteria should provide objective tools to accept or reject specific methods, to validate them, to ensure compatibility between validated methods, and be used on a routine basis to reject data outside an acceptable range of variability. When selecting a method of detection, it is also important to consider its applicability, its field of applications, and its limitations, by including factors such as its ability to detect the target analyte in a given matrix, the duration of the analyses, its cost effectiveness, and the necessary sample sizes for testing. Thus, the current GMO detection methods should be evaluated against a common set of performance criteria.

  5. Method and apparatus for detecting halogenated hydrocarbons

    DOEpatents

    Monagle, Matthew; Coogan, John J.

    1997-01-01

    A halogenated hydrocarbon (HHC) detector is formed from a silent discharge (also called a dielectric barrier discharge) plasma generator. A silent discharge plasma device receives a gas sample that may contain one or more HHCs and produces free radicals and excited electrons for oxidizing the HHCs in the gas sample to produce water, carbon dioxide, and an acid including halogens in the HHCs. A detector is used to sensitively detect the presence of the acid. A conductivity cell detector combines the oxidation products with a solvent where dissociation of the acid increases the conductivity of the solvent. The conductivity cell output signal is then functionally related to the presence of HHCs in the gas sample. Other detectors include electrochemical cells, infrared spectrometers, and negative ion mobility spectrometers.

  6. Sciatica: Detection and Confirmation by New Method

    PubMed Central

    Nadkarni, Sunil

    2014-01-01

    We need to overcome limitations of present assessment and also integrate newer research in our work about sciatica. Inflammation induces changes in the DRG and nerve root. It sensitizes the axons. Nociceptor is a unique axon. It is pseudo unipolar: both its ends, central and peripheral, behave in similar fashion. The nerve in periphery which carries these axons may selectively become sensitive to mechanical pressure--“mechanosensitized,” as we coin the phrase. Many pain questionnaires are used and are effective in identifying neuropathic pain solely on basis of descriptors but they do not directly physically correlate nerve root and pain. A thorough neurological evaluation is always needed. Physical examination is not direct pain assessment but testing mobility of nerve root and its effect on pain generation. There is a dogmatic dominance of dermatomes in assessment of leg pain. They are unreliable. Images may not correlate with symptoms and pathology in about 28% of cases. Electrophysiology may be normal in purely inflamed nerve root. Palpation may help in such inflammatory setting to refine our assessment further. Confirmation of sciatica is done by selective nerve root block (SNRB) today but it is fraught with several complications and needs elaborate inpatient and operating room set up. We have used the unique property of the pseudo unipolar axon that both its ends have similar functional properties and so inject along its peripheral end sodium channel blockers to block the basic cause of the mechanosensitization namely upregulated sodium channels in the root or DRG. Thus using palpation we may be able to detect symptomatic nerve in stage of inflammation and with distal end injection, along same inflamed nerve we may be able to abolish and so confirm sciatica. Discussions of sciatica pain diagnosis tend to immediately shift and centre on the affected disc rather than the nerve. Theoretically it may be possible to detect the affected nerve by palpating the

  7. Methods for detection of ataxia telangiectasia mutations

    DOEpatents

    Gatti, Richard A.

    2005-10-04

    The present invention is directed to a method of screening large, complex, polyexonic eukaryotic genes such as the ATM gene for mutations and polymorphisms by an improved version of single strand conformation polymorphism (SSCP) electrophoresis that allows electrophoresis of two or three amplified segments in a single lane. The present invention also is directed to new mutations and polymorphisms in the ATM gene that are useful in performing more accurate screening of human DNA samples for mutations and in distinguishing mutations from polymorphisms, thereby improving the efficiency of automated screening methods.

  8. A numerical method of detecting singularity

    NASA Technical Reports Server (NTRS)

    Laporte, M.; Vignes, J.

    1978-01-01

    A numerical method is reported which determines a value C for the degree of conditioning of a matrix. This value is C = 0 for a singular matrix and has progressively larger values for matrices which are increasingly well-conditioned. This value is C sub = C max sub max (C defined by the precision of the computer) when the matrix is perfectly well conditioned.

  9. An edge detection method for strong noisy image using shearlets

    NASA Astrophysics Data System (ADS)

    Li, Yuming; Cao, Hanqiang; Xu, Zijian

    2011-11-01

    Numerous edge detection methods have been proposed to detect image edges. However, these methods are not very effective in detecting edges in strong noisy images. Recent years, multiscale analysis has been introduced to the realm of image processing. As the third generation wavelet, shearlets have their own superiority. Anisotropic dilation operator and shear operator are introduced to overcome the shortcomings of traditional wavelets. Because of their sensitivity to directions, shearlets are apt to do the job of edge detection. Based on shearlets, in this paper, a new edge detection method is proposed. The main idea about this new method is combining the shearlet denoising method with the edge detecting method based on shearlets. Analyzing results show that edges are characterized as zerocrossing points in shearlet domain and can be extracted from shearlet transform coefficients by detecting zero crossing points and using boundary tracking method. Many experiments are conducted to test this novel approach and we also compare Sobel, Log and Canny operators with this new method. Experiments demonstrate that when an image existing high deviation Gaussian noise, this method are much better than ordinary edge detection operators in time domain.

  10. Multimode nondestructive detecting method for high-speed rail defects

    NASA Astrophysics Data System (ADS)

    Sun, Mingjian; Cheng, Xingzhen; Wan, Guangnan; Liu, Ting; Fu, Ying; Wang, Yan

    2015-11-01

    It is very important to detect the surface defects of the high-speed rail for security concerns. A multimode detecting method, which integrates high resolution of optical image, high precision of photoacoustic detection and strong penetration of ultrasound detecting, is proposed for the rail defect detection. Utilizing the surface defect characteristics obtained from optical signal, the photoacoustic and ultrasound scanning region could be determined, and rail shallow and internal defect characteristics can be acquired subsequently. Eventually, fusing three modal signals mentioned above, the information of the entire rail defect, including type, extension trend and depth can be detected. It has been proved that the multimode method can improve the detecting efficiency, and enlarge the detection range in the meantime.

  11. Method of Detecting Coliform Bacteria from Reflected Light

    NASA Technical Reports Server (NTRS)

    Vincent, Robert K. (Inventor)

    2014-01-01

    The present invention relates to a method of detecting coliform bacteria in water from reflected light, and also includes devices for the measurement, calculation and transmission of data relating to that method.

  12. The internal defects detection in crystals by digital holographic methods

    NASA Astrophysics Data System (ADS)

    Dyomin, V. V.; Polovcev, I. G.; Kamenev, D. V.

    2016-08-01

    The internal defects detection method is suggested for crystals intended for the use in the IR part of spectrum. The method is tested on samples of the ZnGeP2 monocrystals, the experimental results are shown.

  13. Laser pulse detection method and apparatus

    NASA Technical Reports Server (NTRS)

    Goss, W.; Janesick, J. R. (Inventor)

    1984-01-01

    A sensor is described for detecting the difference in phase of a pair of returned light pulse components, such as two components of a light pulse of an optical gyro. In an optic gyro, the two light components have passed in opposite directions through a coil of optical fiber, with the difference in phase of the returned light components determining the intensity of light shining on the sensor. The sensor includes a CCD (charge coupled device) that receives the pair of returned light components to generate a charge proportional to the number of photons in the received light. The amount of the charge represents the phase difference between the two light components. At a time after the transmission of the light pulse and before the expected time of arrival of the interfering light components, charge accumulating in the CCD as a result of reflections from components in the system, are repeatedly removed from the CCD, by transferring out charges in the CCD and dumping these charges.

  14. Laser pulse detection method and apparatus

    NASA Technical Reports Server (NTRS)

    Goss, Willis C. (Inventor); Janesick, James R. (Inventor)

    1987-01-01

    A sensor is described for detecting the difference in phase of a pair of returned light pulse components, such as the two components of a light pulse of an optical gyro. In an optic gyro, the two light components have passed in opposite directions through a coil of optical fiber, with the difference in phase of the returned light components determining the intensity of light shining on the sensor. The sensor includes a CCD (charge coupled device) that receives the pair of returned light components to generate a charge proportional to the number of photons in the received light. The amount of the charge represents the phase difference between the two light components. At a time after the transmission of the light pulse and before the expected time of arrival of the interfering light components, charge accumulating in the CCD as a result of reflections from optical components in the system, are repeatedly removed from the CCD, by transferring out charges in the CCD and dumping these charges.

  15. Heterodyne method for high specificity gas detection.

    NASA Technical Reports Server (NTRS)

    Dimeff, J.; Donaldson, R. W.; Gunter, W. D., Jr.; Jaynes, D. N.; Margozzi, A. P.; Deboo, G. J.; Mcclatchie, E. A.; Williams, K. G.

    1971-01-01

    This paper describes a new technique for measuring trace quantities of gases. The technique involves the use of a reference cell (containing a known amount of the gas being sought) and a sample cell (containing an unknown amount of the same gas) wherein the gas densities are modulated. Light passing through the two cells in sequence is modulated in intensity at the vibrational-rotational lines characteristic of the absorption spectrum for the gas of interest. Since the absorption process is nonlinear, modulating the two absorption cells at two different frequencies gives rise to a heterodyning effect, which in turn introduces sum and difference frequencies in the detected signal. Measuring the ratio of the difference frequency signal for example, to the signal introduced by the reference cell provides a normalized measure of the amount of the gas in the sample cell. The readings produced are thereby independent of source intensity, window transparency, and detector sensitivity. Experimental evaluation of the technique suggests that it should be applicable to a wide range of gases, that it should be able to reject spurious signals due to unwanted gases, and that it should be sensitive to concentrations of the order of 10 to the minus 8th power when used with a sample cell of only 20 cm length.

  16. Method for detection of antibodies for metallic elements

    DOEpatents

    Barrick, Charles W.; Clarke, Sara M.; Nordin, Carl W.

    1993-11-30

    An apparatus and method for detecting antibodies specific to non-protein antigens. The apparatus is an immunological plate containing a plurality of plastic projections coated with a non-protein material. Assays utilizing the plate are capable of stabilizing the non-protein antigens with detection levels for antibodies specific to the antigens on a nanogram level. A screening assay with the apparatus allows for early detection of exposure to non-protein materials. Specifically metallic elements are detected.

  17. Method for detection of antibodies for metallic elements

    DOEpatents

    Barrick, C.W.; Clarke, S.M.; Nordin, C.W.

    1993-11-30

    An apparatus and method for detecting antibodies specific to non-protein antigens. The apparatus is an immunological plate containing a plurality of plastic projections coated with a non-protein material. Assays utilizing the plate are capable of stabilizing the non-protein antigens with detection levels for antibodies specific to the antigens on a nanogram level. A screening assay with the apparatus allows for early detection of exposure to non-protein materials. Specifically metallic elements are detected. 10 figures.

  18. Islanding detection scheme based on adaptive identifier signal estimation method.

    PubMed

    Bakhshi, M; Noroozian, R; Gharehpetian, G B

    2017-09-12

    This paper proposes a novel, passive-based anti-islanding method for both inverter and synchronous machine-based distributed generation (DG) units. Unfortunately, when the active/reactive power mismatches are near to zero, majority of the passive anti-islanding methods cannot detect the islanding situation, correctly. This study introduces a new islanding detection method based on exponentially damped signal estimation method. The proposed method uses adaptive identifier method for estimating of the frequency deviation of the point of common coupling (PCC) link as a target signal that can detect the islanding condition with near-zero active power imbalance. Main advantage of the adaptive identifier method over other signal estimation methods is its small sampling window. In this paper, the adaptive identifier based islanding detection method introduces a new detection index entitled decision signal by estimating of oscillation frequency of the PCC frequency and can detect islanding conditions, properly. In islanding conditions, oscillations frequency of PCC frequency reach to zero, thus threshold setting for decision signal is not a tedious job. The non-islanding transient events, which can cause a significant deviation in the PCC frequency are considered in simulations. These events include different types of faults, load changes, capacitor bank switching, and motor starting. Further, for islanding events, the capability of the proposed islanding detection method is verified by near-to-zero active power mismatches. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  19. Ultra-high sensitivity radiation detection apparatus and method

    DOEpatents

    Gross, Kenneth C.; Valentine, John D.; Markum, Francis; Zawadzki, Mary; Dickerman, Charles

    1999-01-01

    A method and apparatus are provided to concentrate and detect very low levels of radioactive noble gases from the atmosphere. More specifically the invention provides a method and apparatus to concentrate xenon, krypton and radon in an organic fluid and to detect these gases by the radioactive emissions.

  20. Criteria For Evaluation of Proposed Protozoan Detection Methods

    EPA Science Inventory

    Currently, the only EPA approved method for detection and quantitation of protozoan cysts and oöcysts in source and drinking water, is the “ICR Protozoan Method for Detecting Giardia Cysts and Cryptosporidium Oöcysts in Water by a Fluorescent Antibody Procedure (ICR Microbial La...

  1. Criteria For Evaluation of Proposed Protozoan Detection Methods

    EPA Science Inventory

    Currently, the only EPA approved method for detection and quantitation of protozoan cysts and oöcysts in source and drinking water, is the “ICR Protozoan Method for Detecting Giardia Cysts and Cryptosporidium Oöcysts in Water by a Fluorescent Antibody Procedure (ICR Microbial La...

  2. Use of molecular methods for the detection of fungal spores.

    PubMed

    Ward, Elaine

    2009-01-01

    Traditional methods for the isolation and identification of fungal spores can be time-consuming and laborious. DNA-based methods for fungal detection can be used to detect the spores of plant-pathogenic fungi. Air borne spores can be collected and identified by PCR allowing identification of the species.

  3. Localized surface plasmon resonance mercury detection system and methods

    DOEpatents

    James, Jay; Lucas, Donald; Crosby, Jeffrey Scott; Koshland, Catherine P.

    2016-03-22

    A mercury detection system that includes a flow cell having a mercury sensor, a light source and a light detector is provided. The mercury sensor includes a transparent substrate and a submonolayer of mercury absorbing nanoparticles, e.g., gold nanoparticles, on a surface of the substrate. Methods of determining whether mercury is present in a sample using the mercury sensors are also provided. The subject mercury detection systems and methods find use in a variety of different applications, including mercury detecting applications.

  4. Method for detecting trace impurities in gases

    DOEpatents

    Freund, Samuel M.; Maier, II, William B.; Holland, Redus F.; Beattie, Willard H.

    1981-01-01

    A technique for considerably improving the sensitivity and specificity of infrared spectrometry as applied to quantitative determination of trace impurities in various carrier or solvent gases is presented. A gas to be examined for impurities is liquefied and infrared absorption spectra of the liquid are obtained. Spectral simplification and number densities of impurities in the optical path are substantially higher than are obtainable in similar gas-phase analyses. Carbon dioxide impurity (.about.2 ppm) present in commercial Xe and ppm levels of Freon 12 and vinyl chloride added to liquefied air are used to illustrate the method.

  5. Method for detecting trace impurities in gases

    SciTech Connect

    Beattie, W.H.; Freund, S.M.; Holland, R.F.; Maier, W.B.

    1981-04-28

    A technique for considerably improving the sensitivity and specificity of infrared spectrometry as applied to quantitative determination of trace impurities in various carrier or solvent gases is presented. A gas to be examined for impurities is liquefied and infrared absorption spectra of the liquid are obtained. Spectral simplification and number densities of impurities in the optical path are substantially higher than are obtainable in similar gas-phase analyses. Carbon dioxide impurity (*2 ppm) present in commercial xe and ppm levels of freon 12 and vinyl chloride added to liquefied air are used to illustrate the method.

  6. Apertureless SPM method of light detection

    SciTech Connect

    Dunaevskiy, M.; Alekseev, P.; Dontsov, A.; Monakhov, A.; Girard, P.; Arinero, R.; Teissier, R.; Baranov, A.

    2016-06-17

    We demonstrate the effect of infrared (IR) illumination on mechanical resonance frequency of scanning probe microscope (SPM) probe. The analytical estimations permit to relate the observed effect with the SPM-probe heating by IR-radiation. This effect can be used for the SPM mapping of IR-radiation spatial distribution on the emitting surfaces. The proposed method demonstrates high sensitivity to the infrared radiation and lateral resolution in the sub-micron range. It was applied to visualize complex spatial structure of lasing modes on the mirror of whispering-gallery mode GaSb/GaAlAsSb/GaInAsSb laser.

  7. Method for detecting trace impurities in gases

    DOEpatents

    Freund, S.M.; Maier, W.B. II; Holland, R.F.; Beattie, W.H.

    A technique for considerably improving the sensitivity and specificity of infrared spectrometry as applied to quantitative determination of trace impurities in various carrier or solvent gases is presented. A gas to be examined for impurities is liquefied and infrared absorption spectra of the liquid are obtained. Spectral simplification and number densities of impurities in the optical path are substantially higher than are obtainable in similar gas-phase analyses. Carbon dioxide impurity (approx. 2 ppM) present in commercial Xe and ppM levels of Freon 12 and vinyl chloride added to liquefied air are used to illustrate the method.

  8. Vapor generation methods for explosives detection research

    SciTech Connect

    Grate, Jay W.; Ewing, Robert G.; Atkinson, David A.

    2012-12-01

    The generation of calibrated vapor samples of explosives compounds remains a challenge due to the low vapor pressures of the explosives, adsorption of explosives on container and tubing walls, and the requirement to manage (typically) multiple temperature zones as the vapor is generated, diluted, and delivered. Methods that have been described to generate vapors can be classified as continuous or pulsed flow vapor generators. Vapor sources for continuous flow generators are typically explosives compounds supported on a solid support, or compounds contained in a permeation or diffusion device. Sources are held at elevated isothermal temperatures. Similar sources can be used for pulsed vapor generators; however, pulsed systems may also use injection of solutions onto heated surfaces with generation of both solvent and explosives vapors, transient peaks from a gas chromatograph, or vapors generated by s programmed thermal desorption. This article reviews vapor generator approaches with emphasis on the method of generating the vapors and on practical aspects of vapor dilution and handling. In addition, a gas chromatographic system with two ovens that is configurable with up to four heating ropes is proposed that could serve as a single integrated platform for explosives vapor generation and device testing. Issues related to standards, calibration, and safety are also discussed.

  9. Delamination detection using methods of computational intelligence

    NASA Astrophysics Data System (ADS)

    Ihesiulor, Obinna K.; Shankar, Krishna; Zhang, Zhifang; Ray, Tapabrata

    2012-11-01

    Abstract Reliable delamination prediction scheme is indispensable in order to prevent potential risks of catastrophic failures in composite structures. The existence of delaminations changes the vibration characteristics of composite laminates and hence such indicators can be used to quantify the health characteristics of laminates. An approach for online health monitoring of in-service composite laminates is presented in this paper that relies on methods based on computational intelligence. Typical changes in the observed vibration characteristics (i.e. change in natural frequencies) are considered as inputs to identify the existence, location and magnitude of delaminations. The performance of the proposed approach is demonstrated using numerical models of composite laminates. Since this identification problem essentially involves the solution of an optimization problem, the use of finite element (FE) methods as the underlying tool for analysis turns out to be computationally expensive. A surrogate assisted optimization approach is hence introduced to contain the computational time within affordable limits. An artificial neural network (ANN) model with Bayesian regularization is used as the underlying approximation scheme while an improved rate of convergence is achieved using a memetic algorithm. However, building of ANN surrogate models usually requires large training datasets. K-means clustering is effectively employed to reduce the size of datasets. ANN is also used via inverse modeling to determine the position, size and location of delaminations using changes in measured natural frequencies. The results clearly highlight the efficiency and the robustness of the approach.

  10. Conditional anomaly detection methods for patient–management alert systems

    PubMed Central

    Valko, Michal; Cooper, Gregory; Seybert, Amy; Visweswaran, Shyam; Saul, Melissa; Hauskrecht, Milos

    2010-01-01

    Anomaly detection methods can be very useful in identifying unusual or interesting patterns in data. A recently proposed conditional anomaly detection framework extends anomaly detection to the problem of identifying anomalous patterns on a subset of attributes in the data. The anomaly always depends (is conditioned) on the value of remaining attributes. The work presented in this paper focuses on instance–based methods for detecting conditional anomalies. The methods rely on the distance metric to identify examples in the dataset that are most critical for detecting the anomaly. We investigate various metrics and metric learning methods to optimize the performance of the instance–based anomaly detection methods. We show the benefits of the instance–based methods on two real–world detection problems: detection of unusual admission decisions for patients with the community–acquired pneumonia and detection of unusual orders of an HPF4 test that is used to confirm Heparin induced thrombocytopenia — a life–threatening condition caused by the Heparin therapy. PMID:25392850

  11. Conditional anomaly detection methods for patient-management alert systems.

    PubMed

    Valko, Michal; Cooper, Gregory; Seybert, Amy; Visweswaran, Shyam; Saul, Melissa; Hauskrecht, Milos

    2008-07-01

    Anomaly detection methods can be very useful in identifying unusual or interesting patterns in data. A recently proposed conditional anomaly detection framework extends anomaly detection to the problem of identifying anomalous patterns on a subset of attributes in the data. The anomaly always depends (is conditioned) on the value of remaining attributes. The work presented in this paper focuses on instance-based methods for detecting conditional anomalies. The methods rely on the distance metric to identify examples in the dataset that are most critical for detecting the anomaly. We investigate various metrics and metric learning methods to optimize the performance of the instance-based anomaly detection methods. We show the benefits of the instance-based methods on two real-world detection problems: detection of unusual admission decisions for patients with the community-acquired pneumonia and detection of unusual orders of an HPF4 test that is used to confirm Heparin induced thrombocytopenia - a life-threatening condition caused by the Heparin therapy.

  12. A detection method of signal frequency based on optimization theory

    NASA Astrophysics Data System (ADS)

    Nie, Chunyan; Shi, Yaowu; Wang, Zhuwen; Guo, Bin

    2006-11-01

    The sensitive characteristic to initial value of chaos system and the immunity to noise sufficiently demonstrate the superiority in weak signal detection. In this paper Duffing equation is used as system detection model, on the basis of optimization theory, a most optimization searching method, which takes the variance of output X as the detected value is present. The basic principle and the theoretical algorithm about detecting the weak signal with this method are proposed. At the same time, the simulation experiments and the result analysis are given. The results indicated this method is rapidly, simple, convenient and the accuracy is high, which is a novel detecting frequency method. If this method were applied in signal processing field or other application field, it would have practical significance.

  13. Method And Apparatus For Detecting Chemical Binding

    DOEpatents

    Warner, Benjamin P.; Havrilla, George J.; Miller, Thomasin C.; Wells, Cyndi A.

    2005-02-22

    The method for screening binding between a target binder and potential pharmaceutical chemicals involves sending a solution (preferably an aqueous solution) of the target binder through a conduit to a size exclusion filter, the target binder being too large to pass through the size exclusion filter, and then sending a solution of one or more potential pharmaceutical chemicals (preferably an aqueous solution) through the same conduit to the size exclusion filter after target binder has collected on the filter. The potential pharmaceutical chemicals are small enough to pass through the filter. Afterwards, x-rays are sent from an x-ray source to the size exclusion filter, and if the potential pharmaceutical chemicals form a complex with the target binder, the complex produces an x-ray fluorescence signal having an intensity that indicates that a complex has formed.

  14. Method and apparatus for detecting chemical binding

    DOEpatents

    Warner, Benjamin P.; Havrilla, George J.; Miller, Thomasin C.; Wells, Cyndi A.

    2007-07-10

    The method for screening binding between a target binder and potential pharmaceutical chemicals involves sending a solution (preferably an aqueous solution) of the target binder through a conduit to a size exclusion filter, the target binder being too large to pass through the size exclusion filter, and then sending a solution of one or more potential pharmaceutical chemicals (preferably an aqueous solution) through the same conduit to the size exclusion filter after target binder has collected on the filter. The potential pharmaceutical chemicals are small enough to pass through the filter. Afterwards, x-rays are sent from an x-ray source to the size exclusion filter, and if the potential pharmaceutical chemicals form a complex with the target binder, the complex produces an x-ray fluorescence signal having an intensity that indicates that a complex has formed.

  15. Software detection method based on running state

    NASA Astrophysics Data System (ADS)

    Zhao, XiaoLin; Chen, Quanbao; Shan, Chun; Wang, Ting; Zhang, Yiman

    2017-08-01

    It is extremely important for the study of software behavior modeling for software security research. This article determines whether the security of software operation by analyzing the credibility of software behavior, monitoring software running status. This paper focuses on a modeling algorithm, namely the GK-tail algorithm, which based on software behavior modeling method. At the same time, this paper improves the GK-tail algorithm, which focuses on data constraints and the interaction between software components. Restrictions on extending finite automaton can be obtained by using a combination of Daikon and ESC/JAVA tools. Restrictions can improve the accuracy of the generated model. So the generated behavior model can capture more accurate information. Finally, the paper designs and implements the software running state generator. It is feasible through the software state diagram to determine the feasibility of software security proved by the experiment.

  16. Comparison of multi-mode parallel detection microscopy methods

    NASA Astrophysics Data System (ADS)

    Zhu, Dazhao; Fang, Yue; Chen, Youhua; Hussain, Anwar; Kuang, Cuifang; Ding, Zhihua; Liu, Xu

    2017-03-01

    Four microscopy resolution enhancement methods based on parallel detection were investigated in this study: confocal microscopy with four pinhole sizes, fluorescence emission difference microscopy (FED) based on parallel detection, Airyscan microscopy, and virtual k-vector modulation optical microscopy (Vikmom). These methods use different algorithms to process parallel detection data and achieve resolution improvement. We investigated these methods first by performing simulations and then experimentally. In this report, the basic theories of these methods are briefly introduced. Then, analyses and comparisons of their imaging performances, especially in terms of resolution improvement, imaging speed, and signal-to-noise ratio, are presented. Finally, the results of our comparative study are summarized.

  17. System and Method for Multi-Wavelength Optical Signal Detection

    NASA Technical Reports Server (NTRS)

    McGlone, Thomas D. (Inventor)

    2017-01-01

    The system and method for multi-wavelength optical signal detection enables the detection of optical signal levels significantly below those processed at the discrete circuit level by the use of mixed-signal processing methods implemented with integrated circuit technologies. The present invention is configured to detect and process small signals, which enables the reduction of the optical power required to stimulate detection networks, and lowers the required laser power to make specific measurements. The present invention provides an adaptation of active pixel networks combined with mixed-signal processing methods to provide an integer representation of the received signal as an output. The present invention also provides multi-wavelength laser detection circuits for use in various systems, such as a differential absorption light detection and ranging system.

  18. Reliably Detectable Flaw Size for NDE Methods that Use Calibration

    NASA Technical Reports Server (NTRS)

    Koshti, Ajay M.

    2017-01-01

    Probability of detection (POD) analysis is used in assessing reliably detectable flaw size in nondestructive evaluation (NDE). MIL-HDBK-1823 and associated mh1823 POD software gives most common methods of POD analysis. In this paper, POD analysis is applied to an NDE method, such as eddy current testing, where calibration is used. NDE calibration standards have known size artificial flaws such as electro-discharge machined (EDM) notches and flat bottom hole (FBH) reflectors which are used to set instrument sensitivity for detection of real flaws. Real flaws such as cracks and crack-like flaws are desired to be detected using these NDE methods. A reliably detectable crack size is required for safe life analysis of fracture critical parts. Therefore, it is important to correlate signal responses from real flaws with signal responses form artificial flaws used in calibration process to determine reliably detectable flaw size.

  19. [Methods for detection of methylated cytosine residues in DNA].

    PubMed

    Smirnikhina, S A; Lavrov, A V

    2009-01-01

    The article provides analysis of common methods for DNA methylation detection. Advantages and limitations of methods used for different purposes are compared. Clue step for most common methods is bisulfite treatment of DNA samples and its protocol is described in details. Recommendations are formulated for each method best in solving specific problems.

  20. Effects of Linking Methods on Detection of DIF.

    ERIC Educational Resources Information Center

    Kim, Seock-Ho; Cohen, Allan S.

    1992-01-01

    Effects of the following methods for linking metrics on detection of differential item functioning (DIF) were compared: (1) test characteristic curve method (TCC); (2) weighted mean and sigma method; and (3) minimum chi-square method. With large samples, results were essentially the same. With small samples, TCC was most accurate. (SLD)

  1. Effects of Linking Methods on Detection of DIF.

    ERIC Educational Resources Information Center

    Kim, Seock-Ho; Cohen, Allan S.

    1992-01-01

    Effects of the following methods for linking metrics on detection of differential item functioning (DIF) were compared: (1) test characteristic curve method (TCC); (2) weighted mean and sigma method; and (3) minimum chi-square method. With large samples, results were essentially the same. With small samples, TCC was most accurate. (SLD)

  2. Advances in rapid detection methods for foodborne pathogens.

    PubMed

    Zhao, Xihong; Lin, Chii-Wann; Wang, Jun; Oh, Deog Hwan

    2014-03-28

    Food safety is increasingly becoming an important public health issue, as foodborne diseases present a widespread and growing public health problem in both developed and developing countries. The rapid and precise monitoring and detection of foodborne pathogens are some of the most effective ways to control and prevent human foodborne infections. Traditional microbiological detection and identification methods for foodborne pathogens are well known to be time consuming and laborious as they are increasingly being perceived as insufficient to meet the demands of rapid food testing. Recently, various kinds of rapid detection, identification, and monitoring methods have been developed for foodborne pathogens, including nucleic-acid-based methods, immunological methods, and biosensor-based methods, etc. This article reviews the principles, characteristics, and applications of recent rapid detection methods for foodborne pathogens.

  3. Harmonic Motion Microwave Doppler Imaging method for breast tumor detection.

    PubMed

    Top, Can Barıs; Tafreshi, Azadeh Kamali; Gençer, Nevzat G

    2014-01-01

    Harmonic Motion Microwave Doppler Imaging (HMMDI) method is recently proposed as a non-invasive hybrid breast imaging technique for tumor detection. The acquired data depend on acoustic, elastic and electromagnetic properties of the tissue. The potential of the method is analyzed with simulation studies and phantom experiments. In this paper, the results of these studies are summarized. It is shown that HMMDI method has a potential to detect malignancies inside fibro-glandular tissue.

  4. Systems and Methods for Automated Water Detection Using Visible Sensors

    NASA Technical Reports Server (NTRS)

    Rankin, Arturo L. (Inventor); Matthies, Larry H. (Inventor); Bellutta, Paolo (Inventor)

    2016-01-01

    Systems and methods are disclosed that include automated machine vision that can utilize images of scenes captured by a 3D imaging system configured to image light within the visible light spectrum to detect water. One embodiment includes autonomously detecting water bodies within a scene including capturing at least one 3D image of a scene using a sensor system configured to detect visible light and to measure distance from points within the scene to the sensor system, and detecting water within the scene using a processor configured to detect regions within each of the at least one 3D images that possess at least one characteristic indicative of the presence of water.

  5. A novel multi-object detection method in HSV space

    NASA Astrophysics Data System (ADS)

    Tang, Mingfeng; Li, Hongsong; Wen, Yane; Tang, Liping

    2013-07-01

    In order to solve the adverse effects of strong light and shadow on the test results, a fusion frame difference and background subtraction method in the HSV space is used in this paper. By using frame difference method to solve the effect of strong light, but frame difference method can not detect object when the object do not move, the method of background subtraction can detect it, building Gaussian background model in the HSV space can eliminate shadows. Empirical results show that the method of fusion frame difference and background subtraction in the HSV space can get overcome the effect of strong light and shadows. Fusion background subtraction and frame difference method based on establishing a Gaussian mixture model in HSV space can overcome the disadvantages of the frame difference method, at the same time it can also solve the false detection of object which result from the background subtraction method.

  6. 25 Years of Self-organized Criticality: Numerical Detection Methods

    NASA Astrophysics Data System (ADS)

    McAteer, R. T. James; Aschwanden, Markus J.; Dimitropoulou, Michaila; Georgoulis, Manolis K.; Pruessner, Gunnar; Morales, Laura; Ireland, Jack; Abramenko, Valentyna

    2016-01-01

    The detection and characterization of self-organized criticality (SOC), in both real and simulated data, has undergone many significant revisions over the past 25 years. The explosive advances in the many numerical methods available for detecting, discriminating, and ultimately testing, SOC have played a critical role in developing our understanding of how systems experience and exhibit SOC. In this article, methods of detecting SOC are reviewed; from correlations to complexity to critical quantities. A description of the basic autocorrelation method leads into a detailed analysis of application-oriented methods developed in the last 25 years. In the second half of this manuscript space-based, time-based and spatial-temporal methods are reviewed and the prevalence of power laws in nature is described, with an emphasis on event detection and characterization. The search for numerical methods to clearly and unambiguously detect SOC in data often leads us outside the comfort zone of our own disciplines—the answers to these questions are often obtained by studying the advances made in other fields of study. In addition, numerical detection methods often provide the optimum link between simulations and experiments in scientific research. We seek to explore this boundary where the rubber meets the road, to review this expanding field of research of numerical detection of SOC systems over the past 25 years, and to iterate forwards so as to provide some foresight and guidance into developing breakthroughs in this subject over the next quarter of a century.

  7. Extract interaction detection methods from the biological literature

    PubMed Central

    Wang, Hongning; Huang, Minlie; Zhu, Xiaoyan

    2009-01-01

    Background Considerable efforts have been made to extract protein-protein interactions from the biological literature, but little work has been done on the extraction of interaction detection methods. It is crucial to annotate the detection methods in the literature, since different detection methods shed different degrees of reliability on the reported interactions. However, the diversity of method mentions in the literature makes the automatic extraction quite challenging. Results In this article, we develop a generative topic model, the Correlated Method-Word model (CMW model) to extract the detection methods from the literature. In the CMW model, we formulate the correlation between the different methods and related words in a probabilistic framework in order to infer the potential methods from the given document. By applying the model on a corpus of 5319 full text documents annotated by the MINT and IntAct databases, we observe promising results, which outperform the best result reported in the BioCreative II challenge evaluation. Conclusion From the promising experiment results, we can see that the CMW model overcomes the issues caused by the diversity in the method mentions and properly captures the in-depth correlations between the detection methods and related words. The performance outperforming the baseline methods confirms that the dependence assumptions of the model are reasonable and the model is competent for the practical processing. PMID:19208158

  8. A novel method for determining target detection thresholds

    NASA Astrophysics Data System (ADS)

    Grossman, S.

    2015-05-01

    Target detection is the act of isolating objects of interest from the surrounding clutter, generally using some form of test to include objects in the found class. However, the method of determining the threshold is overlooked relying on manual determination either through empirical observation or guesswork. The question remains: how does an analyst identify the detection threshold that will produce the optimum results? This work proposes the concept of a target detection sweet spot where the missed detection probability curve crosses the false detection curve; this represents the point at which missed detects are traded for false detects in order to effect positive or negative changes in the detection probability. ROC curves are used to characterize detection probabilities and false alarm rates based on empirically derived data. It identifies the relationship between the empirically derived results and the first moment statistic of the histogram of the pixel target value data and then proposes a new method of applying the histogram results in an automated fashion to predict the target detection sweet spot at which to begin automated target detection.

  9. A Method of Detections' Fusion for GNSS Anti-Spoofing.

    PubMed

    Tao, Huiqi; Li, Hong; Lu, Mingquan

    2016-12-19

    The spoofing attack is one of the security threats of systems depending on the Global Navigation Satellite System (GNSS). There have been many GNSS spoofing detection methods, and each of them focuses on a characteristic of the GNSS signal or a measurement that the receiver has obtained. The method based on a single detector is insufficient against spoofing attacks in some scenarios. How to fuse multiple detections together is a problem that concerns the performance of GNSS anti-spoofing. Scholars have put forward a model to fuse different detection results based on the Dempster-Shafer theory (DST) of evidence combination. However, there are some problems in the application. The main challenge is the valuation of the belief function, which is a key issue in DST. This paper proposes a practical method of detections' fusion based on an approach to assign the belief function for spoofing detections. The frame of discernment is simplified, and the hard decision of hypothesis testing is replaced by the soft decision; then, the belief functions for some detections can be evaluated. The method is discussed in detail, and a performance evaluation is provided, as well. Detections' fusion reduces false alarms of detection and makes the result more reliable. Experimental results based on public test datasets demonstrate the performance of the proposed method.

  10. A Review of Methods for Detecting Melamine in Food Samples.

    PubMed

    Lu, Yang; Xia, Yinqiang; Liu, Guozhen; Pan, Mingfei; Li, Mengjuan; Lee, Nanju Alice; Wang, Shuo

    2017-01-02

    Melamine is a synthetic chemical used in the manufacture of resins, pigments, and superplasticizers. Human beings can be exposed to melamine through various sources such as migration from related products into foods, pesticide contamination, and illegal addition to foods. Toxicity studies suggest that prolonged consumption of melamine could lead to the formation of kidney stones or even death. Therefore, reliable and accurate detection methods are essential to prevent human exposure to melamine. Sample preparation is of critical importance, since it could directly affect the performance of analytical methods. Some methods for the detection of melamine include instrumental analysis, immunoassays, and sensor methods. In this paper, we have summarized the state-of-the-art methods used for food sample preparation as well as the various detection techniques available for melamine. Combinations of multiple techniques and new materials used in the detection of melamine have also been reviewed. Finally, future perspectives on the applications of microfluidic devices have also been provided.

  11. Method of detecting meter base on image-processing

    NASA Astrophysics Data System (ADS)

    Wang, Hong-ping; Wang, Peng; Yu, Zheng-lin

    2008-03-01

    This paper proposes a new idea of detecting meter using image arithmetic- logic operation and high-precision raster sensor. This method regards the data measured by precision raster as real value, the data obtained by digital image-processing as measuring value, and achieves the aim of detecting meter through the compare of above two datum finally. This method utilizes the dynamic change of meter pointer to complete subtraction processing of image, to realize image segmentation, and to achieve warp-value of image pointer of border time. This method using the technology of image segmentation replaces the traditional method which is low accuracy and low repetition caused by manual operation and ocular reading. Its precision reaches technology index demand according to the arithmetic of nation detecting rules and experiment indicates it is reliable, high accuracy. The paper introduces the total scheme of detecting meter, capturing method of image pointer, and also shows the precision analysis of indicating value error.

  12. Sonoclot(®)-based method to detect iron enhanced coagulation.

    PubMed

    Nielsen, Vance G; Henderson, Jon

    2016-07-01

    Thrombelastographic methods have been recently introduced to detect iron mediated hypercoagulability in settings such as sickle cell disease, hemodialysis, mechanical circulatory support, and neuroinflammation. However, these inflammatory situations may have heme oxygenase-derived, coexistent carbon monoxide present, which also enhances coagulation as assessed by the same thrombelastographic variables that are affected by iron. This brief report presents a novel, Sonoclot-based method to detect iron enhanced coagulation that is independent of carbon monoxide influence. Future investigation will be required to assess the sensitivity of this new method to detect iron mediated hypercoagulability in clinical settings compared to results obtained with thrombelastographic techniques.

  13. Systems and methods for detection of blowout precursors in combustors

    DOEpatents

    Lieuwen, Tim C.; Nair, Suraj

    2006-08-15

    The present invention comprises systems and methods for detecting flame blowout precursors in combustors. The blowout precursor detection system comprises a combustor, a pressure measuring device, and blowout precursor detection unit. A combustion controller may also be used to control combustor parameters. The methods of the present invention comprise receiving pressure data measured by an acoustic pressure measuring device, performing one or a combination of spectral analysis, statistical analysis, and wavelet analysis on received pressure data, and determining the existence of a blowout precursor based on such analyses. The spectral analysis, statistical analysis, and wavelet analysis further comprise their respective sub-methods to determine the existence of blowout precursors.

  14. Performance evaluation of fault detection methods for wastewater treatment processes.

    PubMed

    Corominas, Lluís; Villez, Kris; Aguado, Daniel; Rieger, Leiv; Rosén, Christian; Vanrolleghem, Peter A

    2011-02-01

    Several methods to detect faults have been developed in various fields, mainly in chemical and process engineering. However, minimal practical guidelines exist for their selection and application. This work presents an index that allows for evaluating monitoring and diagnosis performance of fault detection methods, which takes into account several characteristics, such as false alarms, false acceptance, and undesirable switching from correct detection to non-detection during a fault event. The usefulness of the index to process engineering is demonstrated first by application to a simple example. Then, it is used to compare five univariate fault detection methods (Shewhart, EWMA, and residuals of EWMA) applied to the simulated results of the Benchmark Simulation Model No. 1 long-term (BSM1_LT). The BSM1_LT, provided by the IWA Task Group on Benchmarking of Control Strategies, is a simulation platform that allows for creating sensor and actuator faults and process disturbances in a wastewater treatment plant. The results from the method comparison using BSM1_LT show better performance to detect a sensor measurement shift for adaptive methods (residuals of EWMA) and when monitoring the actuator signals in a control loop (e.g., airflow). Overall, the proposed index is able to screen fault detection methods. © 2010 Wiley Periodicals, Inc.

  15. Feature matching method in shaped light mode VFD defect detection

    NASA Astrophysics Data System (ADS)

    Jin, Xuanhong; Dai, Shuguang; Mu, Pingan

    2010-08-01

    In recent years, Vacuum Fluorescent Display (VFD) module in the car audio panel has been widely used. However, due to process reasons, VFD display production process will produce defects, not only affect the appearance, but also affect the display correctly. So building a car VFD display panel defect detection system is of great significance. Machine vision technology is introduced into the automotive VFD display defect detection in order to achieve fast and accurate detection of defects. Shaped light mode is a typical flaw detection mode which is based on characteristics of vehicle VFD panel. According to the image features, learning of the gray matching and feature matching method, we integrated use of feature matching method and the gray level matching method to achieve defect detection.

  16. A method for detection and diagnosis on batch fermentations.

    PubMed

    Dondo, Rodolfo G

    2003-01-01

    In this work we present some basic ideas about detection and diagnosis of faults and abrupt dynamic changes in batch fermentations. Our work focuses on the simultaneous use of two detection methods (residual based and balances based) within the estimation procedure. The idea behind the use of both methods is that the weakness of one of them can be compensated by the use of the other one. Thus the simultaneous use of both methods allows detecting and possibly isolating a wide range of faults. Observations such as the effect of nonlinearities on the detection tests and robustness to model uncertainty are discussed. Numerical results on a particular case, the xanthan gum batch fermentation, are presented. Simulated faults and abnormal behaviors were promptly detected but diagnostics showed mixed results.

  17. Optical methods for the detection of heavy metal ions

    NASA Astrophysics Data System (ADS)

    Uglov, A. N.; Bessmertnykh-Lemeune, A.; Guilard, R.; Averin, A. D.; Beletskaya, I. P.

    2014-03-01

    The review covers an important area of the modern chemistry, namely, the detection of heavy metal ions using optical molecular detectors. The role of this method in metal ion detection and the physicochemical grounds of operation of chemosensors are discussed, and examples of detection of most abundant heavy metal ions and synthetic approaches to molecular detectors are presented. The immobilization of molecular detectors on solid substrates for the design of analytical sensor devices is described. The bibliography includes 178 references.

  18. Method for the detection of Salmonella enterica serovar Enteritidis

    DOEpatents

    Agron, Peter G.; Andersen, Gary L.; Walker, Richard L.

    2008-10-28

    Described herein is the identification of a novel Salmonella enterica serovar Enteritidis locus that serves as a marker for DNA-based identification of this bacterium. In addition, three primer pairs derived from this locus that may be used in a nucleotide detection method to detect the presence of the bacterium are also disclosed herein.

  19. Method of enhancing radiation response of radiation detection materials

    DOEpatents

    Miller, Steven D.

    1997-01-01

    The present invention is a method of increasing radiation response of a radiation detection material for a given radiation signal by first pressurizing the radiation detection material. Pressurization may be accomplished by any means including mechanical and/or hydraulic. In this application, the term "pressure" includes fluid pressure and/or mechanical stress.

  20. Rapid methods for detection of bacterial resistance to antibiotics.

    PubMed

    March-Rosselló, Gabriel Alberto

    2017-03-01

    The most widely used antibiotic susceptibility testing methods in Clinical Microbiology are based on the phenotypic detection of antibiotic resistance by measuring bacterial growth in the presence of the antibiotic being tested. These conventional methods take typically 24hours to obtain results. Here we review the main techniques for rapid determination of antibiotic susceptibility. Data obtained with different methods such as molecular techniques, microarrays, commercial methods used in work routine, immunochromatographic methods, colorimetric methods, image methods, nephelometry, MALDI-TOF mass spectrometry, flow cytometry, chemiluminescence and bioluminescence, microfluids and methods based on cell disruption are analysed in detail.

  1. [Fast Implementation Method of Protein Spots Detection Based on CUDA].

    PubMed

    Xiong, Bangshu; Ye, Yijia; Ou, Qiaofeng; Zhang, Haodong

    2016-02-01

    In order to improve the efficiency of protein spots detection, a fast detection method based on CUDA was proposed. Firstly, the parallel algorithms of the three most time-consuming parts in the protein spots detection algorithm: image preprocessing, coarse protein point detection and overlapping point segmentation were studied. Then, according to single instruction multiple threads executive model of CUDA to adopted data space strategy of separating two-dimensional (2D) images into blocks, various optimizing measures such as shared memory and 2D texture memory are adopted in this study. The results show that the operative efficiency of this method is obviously improved compared to CPU calculation. As the image size increased, this method makes more improvement in efficiency, such as for the image with the size of 2,048 x 2,048, the method of CPU needs 52,641 ms, but the GPU needs only 4,384 ms.

  2. Nested methylation-specific polymerase chain reaction cancer detection method

    DOEpatents

    Belinsky, Steven A.; Palmisano, William A.

    2007-05-08

    A molecular marker-based method for monitoring and detecting cancer in humans. Aberrant methylation of gene promoters is a marker for cancer risk in humans. A two-stage, or "nested" polymerase chain reaction method is disclosed for detecting methylated DNA sequences at sufficiently high levels of sensitivity to permit cancer screening in biological fluid samples, such as sputum, obtained non-invasively. The method is for detecting the aberrant methylation of the p16 gene, O 6-methylguanine-DNA methyltransferase gene, Death-associated protein kinase gene, RAS-associated family 1 gene, or other gene promoters. The method offers a potentially powerful approach to population-based screening for the detection of lung and other cancers.

  3. A novel method to detect shadows on multispectral images

    NASA Astrophysics Data System (ADS)

    Daǧlayan Sevim, Hazan; Yardımcı ćetin, Yasemin; Özışık Başkurt, Didem

    2016-10-01

    Shadowing occurs when the direct light coming from a light source is obstructed by high human made structures, mountains or clouds. Since shadow regions are illuminated only by scattered light, true spectral properties of the objects are not observed in such regions. Therefore, many object classification and change detection problems utilize shadow detection as a preprocessing step. Besides, shadows are useful for obtaining 3D information of the objects such as estimating the height of buildings. With pervasiveness of remote sensing images, shadow detection is ever more important. This study aims to develop a shadow detection method on multispectral images based on the transformation of C1C2C3 space and contribution of NIR bands. The proposed method is tested on Worldview-2 images covering Ankara, Turkey at different times. The new index is used on these 8-band multispectral images with two NIR bands. The method is compared with methods in the literature.

  4. Nested methylation-specific polymerase chain reaction cancer detection method

    DOEpatents

    Belinsky, Steven A.; Palmisano, William A.

    2007-05-08

    A molecular marker-based method for monitoring and detecting cancer in humans. Aberrant methylation of gene promoters is a marker for cancer risk in humans. A two-stage, or "nested" polymerase chain reaction method is disclosed for detecting methylated DNA sequences at sufficiently high levels of sensitivity to permit cancer screening in biological fluid samples, such as sputum, obtained non-invasively. The method is for detecting the aberrant methylation of the p16 gene, O 6-methylguanine-DNA methyltransferase gene, Death-associated protein kinase gene, RAS-associated family 1 gene, or other gene promoters. The method offers a potentially powerful approach to population-based screening for the detection of lung and other cancers.

  5. An improved PCA method with application to boiler leak detection.

    PubMed

    Sun, Xi; Marquez, Horacio J; Chen, Tongwen; Riaz, Muhammad

    2005-07-01

    Principal component analysis (PCA) is a popular fault detection technique. It has been widely used in process industries, especially in the chemical industry. In industrial applications, achieving a sensitive system capable of detecting incipient faults, which maintains the false alarm rate to a minimum, is a crucial issue. Although a lot of research has been focused on these issues for PCA-based fault detection and diagnosis methods, sensitivity of the fault detection scheme versus false alarm rate continues to be an important issue. In this paper, an improved PCA method is proposed to address this problem. In this method, a new data preprocessing scheme and a new fault detection scheme designed for Hotelling's T2 as well as the squared prediction error are developed. A dynamic PCA model is also developed for boiler leak detection. This new method is applied to boiler water/steam leak detection with real data from Syncrude Canada's utility plant in Fort McMurray, Canada. Our results demonstrate that the proposed method can effectively reduce false alarm rate, provide effective and correct leak alarms, and give early warning to operators.

  6. A new ultrasound based method for rapid microorganism detection

    NASA Astrophysics Data System (ADS)

    Shukla, Shiva Kant; Segura, Luis Elvira; Sánchez, Carlos José Sierra; López, Pablo Resa

    2012-05-01

    A new method for rapid detection of catalase positive microorganisms by using an ultrasonic measuring method is proposed in this work. The developed technique is based on the detection of oxygen bubbles produced by the hydrolysis of hydrogen peroxide induced by the enzyme catalase which is present in many microorganisms. The bubbles are trapped in a media based on agar gel which was especially developed for microbiological evaluation. It is found that microorganism concentrations of the order of 105 c.f.u./ml can be detected by using this method. The results obtained show up that the proposed method is competitive with other modern commercial methods like luminescence by ATP system. The method can also be used for characterization of enzyme activity.

  7. Radionuclide detection by inductively coupled plasma mass spectrometry: A comparison of atomic and radiation detection method

    SciTech Connect

    Smith, M.R.; Wyse, E.J.; Koppenaal, D.W.

    1991-04-01

    Radionuclide detection by mass spectrometric techniques offers inherent advantages over conventional radiation detection methods. Since radionuclides decay at variable rates (half-lives) and via various nuclear transformations (i.e. emission of alpha, beta, and/or gamma radiation) their determination via radiation detection depends not only on decay systematics but also on detector technology. Radionuclide detection by direct atom measurement, however, is dependent only on technique sensitivity and is indifferent to decay mode. Evaluation of inductively coupled plasma mass spectrometry (ICP/MS) indicates this method to be superior conventional radiation detection techniques for many radionuclides. This work discusses factors which influence detection by both methods. Illustrative applications of ICP/MS to the ultra-trace determination of several radionuclides, including {sup 129}I, are presented. 20 refs., 6 figs., 1 tab.

  8. A fast automatic target detection method for detecting ships in infrared scenes

    NASA Astrophysics Data System (ADS)

    Özertem, Kemal Arda

    2016-05-01

    Automatic target detection in infrared scenes is a vital task for many application areas like defense, security and border surveillance. For anti-ship missiles, having a fast and robust ship detection algorithm is crucial for overall system performance. In this paper, a straight-forward yet effective ship detection method for infrared scenes is introduced. First, morphological grayscale reconstruction is applied to the input image, followed by an automatic thresholding onto the suppressed image. For the segmentation step, connected component analysis is employed to obtain target candidate regions. At this point, it can be realized that the detection is defenseless to outliers like small objects with relatively high intensity values or the clouds. To deal with this drawback, a post-processing stage is introduced. For the post-processing stage, two different methods are used. First, noisy detection results are rejected with respect to target size. Second, the waterline is detected by using Hough transform and the detection results that are located above the waterline with a small margin are rejected. After post-processing stage, there are still undesired holes remaining, which cause to detect one object as multi objects or not to detect an object as a whole. To improve the detection performance, another automatic thresholding is implemented only to target candidate regions. Finally, two detection results are fused and post-processing stage is repeated to obtain final detection result. The performance of overall methodology is tested with real world infrared test data.

  9. A novel eyelash detection method for iris recognition.

    PubMed

    Yuan, Weiqi; He, Wei

    2005-01-01

    Iris is often affected by the eyelash noise, when captured under unfavorable condition. Not only the iris localization of inner and outer boundaries, but also iris feature extraction can be affected by eyelash. Therefore, in an iris recognition system, eyelash detection is of great importance for accurate iris recognition. Eyelash can be classified into two classes: (1) separable eyelashes (2) multiple eyelashes. The former are detected by local intensity minimum algorithm, and the latter are detected according to the template mean and standard deviation. Experimental results show that the proposed method can detect eyelash accurately.

  10. Thermoelectric SQUID method for the detection of segregations

    NASA Astrophysics Data System (ADS)

    Hinken, Johann H.; Tavrin, Yury

    2000-05-01

    Aero engine turbine discs are most critical parts. Material inhomogeneities can cause disc fractures during the flight with fatal air disasters. Nondestructive testing (NDT) of the discs in various machining steps is necessary and performed as well as possible. Conventional NDT methods, however, like eddy current testing and ultrasonic testing have unacceptable limits. For example, subsurface segregations often cannot be detected directly but only indirectly in such cases when cracks already have developed from them. This may be too late. A new NDT method, which we call the Thermoelectric SQUID Method, has been developed. It allows for the detection of metallic inclusions within non-ferromagnetic metallic base material. This paper describes the results of a feasibility study on aero engine turbine discs made from Inconel® 718. These contained segregations that had been detected before by anodic etching. With the Thermoelectric SQUID Method, these segregations were detected again, and further segregations below the surfaces have been found, which had not been detected before. For this new NDT method the disc material is quasi-transparent. The Thermoelectric SQUID Method is also useful to detect distributed and localized inhomogeneities in pure metals like niobium sheets for particle accelerators.

  11. Dynamic baseline detection method for power data network service

    NASA Astrophysics Data System (ADS)

    Chen, Wei

    2017-08-01

    This paper proposes a dynamic baseline Traffic detection Method which is based on the historical traffic data for the Power data network. The method uses Cisco's NetFlow acquisition tool to collect the original historical traffic data from network element at fixed intervals. This method uses three dimensions information including the communication port, time, traffic (number of bytes or number of packets) t. By filtering, removing the deviation value, calculating the dynamic baseline value, comparing the actual value with the baseline value, the method can detect whether the current network traffic is abnormal.

  12. Detection of clusters of a rare disease over a large territory: performance of cluster detection methods.

    PubMed

    Goujon-Bellec, Stéphanie; Demoury, Claire; Guyot-Goubin, Aurélie; Hémon, Denis; Clavel, Jacqueline

    2011-10-04

    For many years, the detection of clusters has been of great public health interest. Several detection methods have been developed, the most famous of which is the circular scan method. The present study, which was conducted in the context of a rare disease distributed over a large territory (7675 cases registered over 17 years and located in 1895 units), aimed to evaluate the performance of several of the methods in realistic hot-spot cluster situations. All the methods considered aim to identify the most likely cluster area, i.e. the zone that maximizes the likelihood ratio function, among a set of cluster candidates. The circular and elliptic scan methods were developed to detect regularly shaped clusters. Four other methods that focus on irregularly shaped clusters were also considered (the flexible scan method, the genetic algorithm method, and the double connected and maximum linkage spatial scan methods). The power of the methods was evaluated via Monte Carlo simulations under 27 alternative scenarios that corresponded to three cluster population sizes (20, 45 and 115 expected cases), three cluster shapes (linear, U-shaped and compact) and three relative risk values (1.5, 2.0 and 3.0). Three situations emerged from this power study. All the methods failed to detect the smallest clusters with a relative risk lower than 3.0. The power to detect the largest cluster with relative risk of 1.5 was markedly better for all methods, but, at most, half of the true cluster was captured. For other clusters, either large or with the highest relative risk, the standard elliptic scan method appeared to be the best method to detect linear clusters, while the flexible scan method localized the U-shaped clusters more precisely than other methods. Large compact clusters were detected well by all methods, with better results for the circular and elliptic scan methods. The elliptic scan method and flexible scan method seemed the most able to detect clusters of a rare disease in a

  13. Food adulteration: Sources, health risks, and detection methods.

    PubMed

    Bansal, Sangita; Singh, Apoorva; Mangal, Manisha; Mangal, Anupam K; Kumar, Sanjiv

    2017-04-13

    Adulteration in food has been a concern since the beginning of civilization, as it not only decreases the quality of food products but also results in a number of ill effects on health. Authentic testing of food and adulterant detection of various food products is required for value assessment and to assure consumer protection against fraudulent activities. Through this review we intend to compile different types of adulterations made in different food items, the health risks imposed by these adulterants and detection methods available for them. Concerns about food safety and regulation have ensured the development of various techniques like physical, biochemical/immunological and molecular techniques, for adulterant detection in food. Molecular methods are more preferable when it comes to detection of biological adulterants in food, although physical and biochemical techniques are preferable for detection of other adulterants in food.

  14. Automatic landslide and mudflow detection method via multichannel sparse representation

    NASA Astrophysics Data System (ADS)

    Chao, Chen; Zhou, Jianjun; Hao, Zhuo; Sun, Bo; He, Jun; Ge, Fengxiang

    2015-10-01

    Landslide and mudflow detection is an important application of aerial images and high resolution remote sensing images, which is crucial for national security and disaster relief. Since the high resolution images are often large in size, it's necessary to develop an efficient algorithm for landslide and mudflow detection. Based on the theory of sparse representation and, we propose a novel automatic landslide and mudflow detection method in this paper, which combines multi-channel sparse representation and eight neighbor judgment methods. The whole process of the detection is totally automatic. We make the experiment on a high resolution image of ZhouQu district of Gansu province in China on August, 2010 and get a promising result which proved the effective of using sparse representation on landslide and mudflow detection.

  15. Methods, systems and devices for detecting and locating ferromagnetic objects

    DOEpatents

    Roybal, Lyle Gene [Idaho Falls, ID; Kotter, Dale Kent [Shelley, ID; Rohrbaugh, David Thomas [Idaho Falls, ID; Spencer, David Frazer [Idaho Falls, ID

    2010-01-26

    Methods for detecting and locating ferromagnetic objects in a security screening system. One method includes a step of acquiring magnetic data that includes magnetic field gradients detected during a period of time. Another step includes representing the magnetic data as a function of the period of time. Another step includes converting the magnetic data to being represented as a function of frequency. Another method includes a step of sensing a magnetic field for a period of time. Another step includes detecting a gradient within the magnetic field during the period of time. Another step includes identifying a peak value of the gradient detected during the period of time. Another step includes identifying a portion of time within the period of time that represents when the peak value occurs. Another step includes configuring the portion of time over the period of time to represent a ratio.

  16. Efficient method of image edge detection based on FSVM

    NASA Astrophysics Data System (ADS)

    Cai, Aiping; Xiong, Xiaomei

    2013-07-01

    For efficient object cover edge detection in digital images, this paper studied traditional methods and algorithm based on SVM. It analyzed Canny edge detection algorithm existed some pseudo-edge and poor anti-noise capability. In order to provide a reliable edge extraction method, propose a new detection algorithm based on FSVM. Which contains several steps: first, trains classify sample and gives the different membership function to different samples. Then, a new training sample is formed by increase the punishment some wrong sub-sample, and use the new FSVM classification model for train and test them. Finally the edges are extracted of the object image by using the model. Experimental result shows that good edge detection image will be obtained and adding noise experiments results show that this method has good anti-noise.

  17. Methods for detecting residues of cleaning agents during cleaning validation.

    PubMed

    Westman, L; Karlsson, G

    2000-01-01

    Cleaning validation procedures are carried out in order to assure that residues of cleaning agents are within acceptable limits after the cleaning process. Cleaning agents often consist of a mixture of various surfactants which are in a highly diluted state after the water rinsing procedure has been completed. This makes it difficult to find appropriate analytical methods that are sensitive enough to detect the cleaning agents. In addition, it is advantageous for the analytical methods to be simple to perform and to give results quickly. In this study, four different analytical methods are compared: visual detection of foam, pH, conductivity measurements, and analysis of total organic carbon (TOC). TOC was used as a reference method when evaluating the other three potential methods. The analyses were performed on different dilutions of the cleaning agents Vips Neutral, RBS-25, Debisan and Perform. The results demonstrated that the most sensitive method for analysis of Vips Neutral, Debisan and Perform is visual detection of foam, by which it is possible to detect concentrations of cleaning agents down to 10 micrograms/mL. RBS-25 was not detected below 200 micrograms/mL, probably because it is formulated with low-foaming surfactants. TOC analysis is less sensitive but has the advantage of being a quantitative analysis, while visual detection of foam is a semi-quantitative method. Visual detection of foam is easy to perform, gives a quick result, and requires no expensive instrumentation. The sensitivity of each method was found to be dependent upon the type of cleaning agent that was analyzed.

  18. A method for detecting positive growth autocorrelation without marking individuals.

    PubMed

    Brooks, Mollie E; McCoy, Michael W; Bolker, Benjamin M

    2013-01-01

    In most ecological studies, within-group variation is a nuisance that obscures patterns of interest and reduces statistical power. However, patterns of within-group variability often contain information about ecological processes. In particular, such patterns can be used to detect positive growth autocorrelation (consistent variation in growth rates among individuals in a cohort across time), even in samples of unmarked individuals. Previous methods for detecting autocorrelated growth required data from marked individuals. We propose a method that requires only estimates of within-cohort variance through time, using maximum likelihood methods to obtain point estimates and confidence intervals of the correlation parameter. We test our method on simulated data sets and determine the loss in statistical power due to the inability to identify individuals. We show how to accommodate nonlinear growth trajectories and test the effects of size-dependent mortality on our method's accuracy. The method can detect significant growth autocorrelation at moderate levels of autocorrelation with moderate-sized cohorts (for example, statistical power of 80% to detect growth autocorrelation ρ (2) = 0.5 in a cohort of 100 individuals measured on 16 occasions). We present a case study of growth in the red-eyed tree frog. Better quantification of the processes driving size variation will help ecologists improve predictions of population dynamics. This work will help researchers to detect growth autocorrelation in cases where marking is logistically infeasible or causes unacceptable decreases in the fitness of marked individuals.

  19. A Method for Detecting Positive Growth Autocorrelation without Marking Individuals

    PubMed Central

    Brooks, Mollie E.; McCoy, Michael W.; Bolker, Benjamin M.

    2013-01-01

    In most ecological studies, within-group variation is a nuisance that obscures patterns of interest and reduces statistical power. However, patterns of within-group variability often contain information about ecological processes. In particular, such patterns can be used to detect positive growth autocorrelation (consistent variation in growth rates among individuals in a cohort across time), even in samples of unmarked individuals. Previous methods for detecting autocorrelated growth required data from marked individuals. We propose a method that requires only estimates of within-cohort variance through time, using maximum likelihood methods to obtain point estimates and confidence intervals of the correlation parameter. We test our method on simulated data sets and determine the loss in statistical power due to the inability to identify individuals. We show how to accommodate nonlinear growth trajectories and test the effects of size-dependent mortality on our method's accuracy. The method can detect significant growth autocorrelation at moderate levels of autocorrelation with moderate-sized cohorts (for example, statistical power of 80% to detect growth autocorrelation ρ2 = 0.5 in a cohort of 100 individuals measured on 16 occasions). We present a case study of growth in the red-eyed tree frog. Better quantification of the processes driving size variation will help ecologists improve predictions of population dynamics. This work will help researchers to detect growth autocorrelation in cases where marking is logistically infeasible or causes unacceptable decreases in the fitness of marked individuals. PMID:24204620

  20. Comprehensive methods for earlier detection and monitoring of forest decline

    Treesearch

    Jennifer Pontius; Richard Hallett

    2014-01-01

    Forested ecosystems are threatened by invasive pests, pathogens, and unusual climatic events brought about by climate change. Earlier detection of incipient forest health problems and a quantitatively rigorous assessment method is increasingly important. Here, we describe a method that is adaptable across tree species and stress agents and practical for use in the...

  1. Methods for detection of GMOs in food and feed.

    PubMed

    Marmiroli, Nelson; Maestri, Elena; Gullì, Mariolina; Malcevschi, Alessio; Peano, Clelia; Bordoni, Roberta; De Bellis, Gianluca

    2008-10-01

    This paper reviews aspects relevant to detection and quantification of genetically modified (GM) material within the feed/food chain. The GM crop regulatory framework at the international level is evaluated with reference to traceability and labelling. Current analytical methods for the detection, identification, and quantification of transgenic DNA in food and feed are reviewed. These methods include quantitative real-time PCR, multiplex PCR, and multiplex real-time PCR. Particular attention is paid to methods able to identify multiple GM events in a single reaction and to the development of microdevices and microsensors, though they have not been fully validated for application.

  2. Method of detecting genetic deletions identified with chromosomal abnormalities

    SciTech Connect

    Gray, Joe W; Pinkel, Daniel; Tkachuk, Douglas

    2013-11-26

    Methods and compositions for staining based upon nucleic acid sequence that employ nucleic acid probes are provided. Said methods produce staining patterns that can be tailored for specific cytogenetic analyzes. Said probes are appropriate for in situ hybridization and stain both interphase and metaphase chromosomal material with reliable signals. The nucleic acids probes are typically of a complexity greater tha 50 kb, the complexity depending upon the cytogenetic application. Methods and reagents are provided for the detection of genetic rearrangements. Probes and test kits are provided for use in detecting genetic rearrangements, particlularly for use in tumor cytogenetics, in the detection of disease related loci, specifically cancer, such as chronic myelogenous leukemia (CML) and for biological dosimetry. Methods and reagents are described for cytogenetic research, for the differentiation of cytogenetically similar ut genetically different diseases, and for many prognostic and diagnostic applications.

  3. Method of detecting genetic translocations identified with chromosomal abnormalities

    DOEpatents

    Gray, Joe W.; Pinkel, Daniel; Tkachuk, Douglas

    2001-01-01

    Methods and compositions for staining based upon nucleic acid sequence that employ nucleic acid probes are provided. Said methods produce staining patterns that can be tailored for specific cytogenetic analyses. Said probes are appropriate for in situ hybridization and stain both interphase and metaphase chromosomal material with reliable signals. The nucleic acid probes are typically of a complexity greater than 50 kb, the complexity depending upon the cytogenetic application. Methods and reagents are provided for the detection of genetic rearrangements. Probes and test kits are provided for use in detecting genetic rearrangements, particularly for use in tumor cytogenetics, in the detection of disease related loci, specifically cancer, such as chronic myelogenous leukemia (CML) and for biological dosimetry. Methods and reagents are described for cytogenetic research, for the differentiation of cytogenetically similar but genetically different diseases, and for many prognostic and diagnostic applications.

  4. A Comparison of Satellite-Based Multilayered Cloud Detection Methods

    NASA Technical Reports Server (NTRS)

    Minnis, Patrick; Chang, Fu-Lung; Khaiyer, Mandana M.; Ayers, Jeffrey K.; Palikonda, Rabindra; Nordeen, Michele L.; Spangenberg, Douglas A.

    2007-01-01

    Both techniques show skill in detecting multilayered clouds, but they disagree more than 50% of the time. BTD method tends to detect more ML clouds than CO2 method and has slightly higher detection accuracy. CO2 method might be better for minimizing false positives, but further study is needed. Neither method as been optimized for GOES data. BTD technique developed on AVHRR, better BTD signals & resolution. CO2 developed on MODIS, better resolution & 4 CO2 channels. Many additional comparisons with ARSCL data will be used to optimize both techniques. A combined technique will be examined using MODIS & Meteosat-8 data. After optimization, the techniques will be implemented in the ARM operational satellite cloud processing.

  5. A Bayesian Outbreak Detection Method for Influenza-Like Illness

    PubMed Central

    García, Yury E.; Christen, J. Andrés; Capistrán, Marcos A.

    2015-01-01

    Epidemic outbreak detection is an important problem in public health and the development of reliable methods for outbreak detection remains an active research area. In this paper we introduce a Bayesian method to detect outbreaks of influenza-like illness from surveillance data. The rationale is that, during the early phase of the outbreak, surveillance data changes from autoregressive dynamics to a regime of exponential growth. Our method uses Bayesian model selection and Bayesian regression to identify the breakpoint. No free parameters need to be tuned. However, historical information regarding influenza-like illnesses needs to be incorporated into the model. In order to show and discuss the performance of our method we analyze synthetic, seasonal, and pandemic outbreak data. PMID:26425552

  6. [Molecular Detection Methods for Vibrio parahaemolyticus in Seafood].

    PubMed

    Nishio, Tomohiro; Ohtsuka, Kayoko; Oda, Midori; Sugiyama, Kanji; Hara-Kudo, Yukiko

    2015-07-01

    To detect Vibrio parahaemolyticus in seafood, we evaluated efficient combinations of molecular methods with DNA extraction methods using heat extraction and alkaline heat extraction, and PCR, real-time PCR and loop-mediated isothermal amplification (LAMP) assays were performed targeting V parahaemolyticus species-specific genes (tlh and rpoD) and pathogenic factors genes (tdh and trh). The species-specific genes were detected in all combinations of two strains (a tdh * trh1-positive strain and a trh2-positive strain), two kinds of shellfish (oyster and bloody clams) and molecular methods with tlh-real time PCR or rpoD-LAMP assays with DNA of alkaline heat extraction at 85-145cfu/test level. tdh was detected in both seafoods with real time PCR assay with DNA of heat extraction at 85cfu/test level, and detected with the LAMP and real time PCR assays with DNA of alkaline heat extraction at 85cfu/test level. Detection of both trh1 and trh2 with the PCR assay with DNA of alkaline heat extraction was comparatively high though trh2 was detected with the LAMP assay with DNA of alkaline heat extraction at 145cfu/test level. It, however, is necessary to investigate more sensitive trh-detection methods. In this study, the results indicated that tlh-real time PCR or rpoD-LAMP, tdh-real time PCR and tdh-LAMP assays with DNA of alkaline heat extraction are relatively-sensitive methods to detect V. parahaemolyticus in seafood.

  7. Evaluation of Anomaly Detection Method Based on Pattern Recognition

    NASA Astrophysics Data System (ADS)

    Fontugne, Romain; Himura, Yosuke; Fukuda, Kensuke

    The number of threats on the Internet is rapidly increasing, and anomaly detection has become of increasing importance. High-speed backbone traffic is particularly degraded, but their analysis is a complicated task due to the amount of data, the lack of payload data, the asymmetric routing and the use of sampling techniques. Most anomaly detection schemes focus on the statistical properties of network traffic and highlight anomalous traffic through their singularities. In this paper, we concentrate on unusual traffic distributions, which are easily identifiable in temporal-spatial space (e.g., time/address or port). We present an anomaly detection method that uses a pattern recognition technique to identify anomalies in pictures representing traffic. The main advantage of this method is its ability to detect attacks involving mice flows. We evaluate the parameter set and the effectiveness of this approach by analyzing six years of Internet traffic collected from a trans-Pacific link. We show several examples of detected anomalies and compare our results with those of two other methods. The comparison indicates that the only anomalies detected by the pattern-recognition-based method are mainly malicious traffic with a few packets.

  8. A review on detection methods used for foodborne pathogens

    PubMed Central

    Priyanka, B.; Patil, Rajashekhar K.; Dwarakanath, Sulatha

    2016-01-01

    Foodborne pathogens have been a cause of a large number of diseases worldwide and more so in developing countries. This has a major economic impact. It is important to contain them, and to do so, early detection is very crucial. Detection and diagnostics relied on culture-based methods to begin with and have developed in the recent past parallel to the developments towards immunological methods such as enzyme-linked immunosorbent assays (ELISA) and molecular biology-based methods such as polymerase chain reaction (PCR). The aim has always been to find a rapid, sensitive, specific and cost-effective method. Ranging from culturing of microbes to the futuristic biosensor technology, the methods have had this common goal. This review summarizes the recent trends and brings together methods that have been developed over the years. PMID:28139531

  9. New Optical Methods for Liveness Detection on Fingers

    PubMed Central

    Dolezel, Michal; Vana, Jan; Brezinova, Eva; Yim, Jaegeol; Shim, Kyubark

    2013-01-01

    This paper is devoted to new optical methods, which are supposed to be used for liveness detection on fingers. First we describe the basics about fake finger use in fingerprint recognition process and the possibilities of liveness detection. Then we continue with introducing three new liveness detection methods, which we developed and tested in the scope of our research activities—the first one is based on measurement of the pulse, the second one on variations of optical characteristics caused by pressure change, and the last one is based on reaction of skin to illumination with different wavelengths. The last part deals with the influence of skin diseases on fingerprint recognition, especially on liveness detection. PMID:24151584

  10. Detection of forced oscillations in power systems with multichannel methods

    SciTech Connect

    Follum, James D.

    2015-09-30

    The increasing availability of high fidelity, geographically dispersed measurements in power systems improves the ability of researchers and engineers to study dynamic behaviors in the grid. One such behavior that is garnering increased attention is the presence of forced oscillations. Power system engineers are interested in forced oscillations because they are often symptomatic of the malfunction or misoperation of equipment. Though the resulting oscillation is not always large in amplitude, the root cause may be serious. In this report, multi-channel forced oscillation detection methods are developed. These methods leverage previously developed detection approaches based on the periodogram and spectral-coherence. Making use of geographically distributed channels of data is shown to improved detection performance and shorten the delay before an oscillation can be detected in the online environment. Results from simulated and measured power system data are presented.

  11. A high-throughput multiplex method adapted for GMO detection.

    PubMed

    Chaouachi, Maher; Chupeau, Gaëlle; Berard, Aurélie; McKhann, Heather; Romaniuk, Marcel; Giancola, Sandra; Laval, Valérie; Bertheau, Yves; Brunel, Dominique

    2008-12-24

    A high-throughput multiplex assay for the detection of genetically modified organisms (GMO) was developed on the basis of the existing SNPlex method designed for SNP genotyping. This SNPlex assay allows the simultaneous detection of up to 48 short DNA sequences (approximately 70 bp; "signature sequences") from taxa endogenous reference genes, from GMO constructions, screening targets, construct-specific, and event-specific targets, and finally from donor organisms. This assay avoids certain shortcomings of multiplex PCR-based methods already in widespread use for GMO detection. The assay demonstrated high specificity and sensitivity. The results suggest that this assay is reliable, flexible, and cost- and time-effective for high-throughput GMO detection.

  12. Transistor-based particle detection systems and methods

    DOEpatents

    Jain, Ankit; Nair, Pradeep R.; Alam, Muhammad Ashraful

    2015-06-09

    Transistor-based particle detection systems and methods may be configured to detect charged and non-charged particles. Such systems may include a supporting structure contacting a gate of a transistor and separating the gate from a dielectric of the transistor, and the transistor may have a near pull-in bias and a sub-threshold region bias to facilitate particle detection. The transistor may be configured to change current flow through the transistor in response to a change in stiffness of the gate caused by securing of a particle to the gate, and the transistor-based particle detection system may configured to detect the non-charged particle at least from the change in current flow.

  13. Methods and systems for remote detection of gases

    DOEpatents

    Johnson, Timothy J.

    2007-11-27

    Novel systems and methods for remotely detecting at least one constituent of a gas via infrared detection are provided. A system includes at least one extended source of broadband infrared radiation and a spectrally sensitive receiver positioned remotely from the source. The source and the receiver are oriented such that a surface of the source is in the field of view of the receiver. The source includes a heating component thermally coupled to the surface, and the heating component is configured to heat the surface to a temperature above ambient temperature. The receiver is operable to collect spectral infrared absorption data representative of a gas present between the source and the receiver. The invention advantageously overcomes significant difficulties associated with active infrared detection techniques known in the art, and provides an infrared detection technique with a much greater sensitivity than passive infrared detection techniques known in the art.

  14. Methods and systems for remote detection of gases

    DOEpatents

    Johnson, Timothy J

    2012-09-18

    Novel systems and methods for remotely detecting at least one constituent of a gas via infrared detection are provided. A system includes at least one extended source of broadband infrared radiation and a spectrally sensitive receiver positioned remotely from the source. The source and the receiver are oriented such that a surface of the source is in the field of view of the receiver. The source includes a heating component thermally coupled to the surface, and the heating component is configured to heat the surface to a temperature above ambient temperature. The receiver is operable to collect spectral infrared absorption data representative of a gas present between the source and the receiver. The invention advantageously overcomes significant difficulties associated with active infrared detection techniques known in the art, and provides an infrared detection technique with a much greater sensitivity than passive infrared detection techniques known in the art.

  15. A novel exploratory method for visual recombination detection

    PubMed Central

    Strimmer, Korbinian; Forslund, Kristoffer; Holland, Barbara; Moulton, Vincent

    2003-01-01

    A versatile visual approach for detecting recombination and identifying recombination breakpoints within a sequence alignment is presented. The method is based on two novel diagrams - the highway plot and the occupancy plot - that graphically portray phylogenetic inhomogeneity along an alignment, and can be viewed as a synthesis of two widely used but unrelated methods: bootscanning and quartet-mapping. To illustrate the method, simulated data and HIV-1 and influenza A datasets are investigated. PMID:12734013

  16. Maximum patch method for directional dark matter detection

    NASA Astrophysics Data System (ADS)

    Henderson, Shawn; Monroe, Jocelyn; Fisher, Peter

    2008-07-01

    Present and planned dark matter detection experiments search for WIMP-induced nuclear recoils in poorly known background conditions. In this environment, the maximum gap statistical method provides a way of setting more sensitive cross section upper limits by incorporating known signal information. We give a recipe for the numerical calculation of upper limits for planned directional dark matter detection experiments, that will measure both recoil energy and angle, based on the gaps between events in two-dimensional phase space.

  17. A generic nuclei detection method for histopathological breast images

    NASA Astrophysics Data System (ADS)

    Kost, Henning; Homeyer, André; Bult, Peter; Balkenhol, Maschenka C. A.; van der Laak, Jeroen A. W. M.; Hahn, Horst K.

    2016-03-01

    The detection of cell nuclei plays a key role in various histopathological image analysis problems. Considering the high variability of its applications, we propose a novel generic and trainable detection approach. Adaption to specific nuclei detection tasks is done by providing training samples. A trainable deconvolution and classification algorithm is used to generate a probability map indicating the presence of a nucleus. The map is processed by an extended watershed segmentation step to identify the nuclei positions. We have tested our method on data sets with different stains and target nuclear types. We obtained F1-measures between 0.83 and 0.93.

  18. Method and apparatus for detecting laminar flow separation and reattachment

    NASA Technical Reports Server (NTRS)

    Stack, John P. (Inventor); Mangalam, Sivaramakrishnan M. (Inventor)

    1990-01-01

    The invention is a method and apparatus for simultaneously detecting laminar separation and reattachment of a fluid stream such as an airstream from and to the upper surface of an airfoil by simultaneously sensing and comparing a plurality of output signals. Each signal represents the dynamic shear stress at one of an equal number of sensors spaced along a straight line on the surface of the airfoil that extends parallel to the airstream. The output signals are simultaneously compared to detect the sensors across which a reversal in phase of said output signal occurs, said detected sensors being in the region of laminar separation or reattachment.

  19. Radiometric method for the rapid detection of Leptospira organisms

    SciTech Connect

    Manca, N.; Verardi, R.; Colombrita, D.; Ravizzola, G.; Savoldi, E.; Turano, A.

    1986-02-01

    A rapid and sensitive radiometric method for detection of Leptospira interrogans serovar pomona and Leptospira interrogans serovar copenhageni is described. Stuart's medium and Middlebrook TB (12A) medium supplemented with bovine serum albumin, catalase, and casein hydrolysate and labeled with /sup 14/C-fatty acids were used. The radioactivity was measured in a BACTEC 460. With this system, Leptospira organisms were detected in human blood in 2 to 5 days, a notably shorter time period than that required for the majority of detection techniques.

  20. Safety assessment and detection methods of genetically modified organisms.

    PubMed

    Xu, Rong; Zheng, Zhe; Jiao, Guanglian

    2014-01-01

    Genetically modified organisms (GMOs), are gaining importance in agriculture as well as the production of food and feed. Along with the development of GMOs, health and food safety concerns have been raised. These concerns for these new GMOs make it necessary to set up strict system on food safety assessment of GMOs. The food safety assessment of GMOs, current development status of safety and precise transgenic technologies and GMOs detection have been discussed in this review. The recent patents about GMOs and their detection methods are also reviewed. This review can provide elementary introduction on how to assess and detect GMOs.

  1. Method and automated apparatus for detecting coliform organisms

    NASA Technical Reports Server (NTRS)

    Dill, W. P.; Taylor, R. E.; Jeffers, E. L. (Inventor)

    1980-01-01

    Method and automated apparatus are disclosed for determining the time of detection of metabolically produced hydrogen by coliform bacteria cultured in an electroanalytical cell from the time the cell is inoculated with the bacteria. The detection time data provides bacteria concentration values. The apparatus is sequenced and controlled by a digital computer to discharge a spent sample, clean and sterilize the culture cell, provide a bacteria nutrient into the cell, control the temperature of the nutrient, inoculate the nutrient with a bacteria sample, measures the electrical potential difference produced by the cell, and measures the time of detection from inoculation.

  2. Machine Learning Methods for Attack Detection in the Smart Grid.

    PubMed

    Ozay, Mete; Esnaola, Inaki; Yarman Vural, Fatos Tunay; Kulkarni, Sanjeev R; Poor, H Vincent

    2016-08-01

    Attack detection problems in the smart grid are posed as statistical learning problems for different attack scenarios in which the measurements are observed in batch or online settings. In this approach, machine learning algorithms are used to classify measurements as being either secure or attacked. An attack detection framework is provided to exploit any available prior knowledge about the system and surmount constraints arising from the sparse structure of the problem in the proposed approach. Well-known batch and online learning algorithms (supervised and semisupervised) are employed with decision- and feature-level fusion to model the attack detection problem. The relationships between statistical and geometric properties of attack vectors employed in the attack scenarios and learning algorithms are analyzed to detect unobservable attacks using statistical learning methods. The proposed algorithms are examined on various IEEE test systems. Experimental analyses show that machine learning algorithms can detect attacks with performances higher than attack detection algorithms that employ state vector estimation methods in the proposed attack detection framework.

  3. Methods for detecting compression wood in green and dry conditions

    NASA Astrophysics Data System (ADS)

    Nystrom, Jan; Hagman, Olle

    1999-09-01

    The living softwood tree forms compression wood to compensate for external loads during growth, which creates wood fibers with higher longitudinal shrinking and swelling than normal wood at moisture content changes. This is often the cause of undesirable warping of sawn wood products after drying. An automatic detection of severe compression wood is thus useful to reject unwanted pieces. Detection in green condition is often preferred in a sawmill while detection in dry condition is needed in other applications. Three different non- destructive scanning methods were evaluated on both green and dry wood surfaces. The methods used were RGB (red, green, blue) color scanning, tracheid-effect scanning and x-ray scanning. The color and x-ray methods were evaluated on Southern yellow pine lumber, while the tracheid-effect scanning was tested on Norway spruce. For scanning in green condition detection of compression wood was good using the tracheid-effect and color scanning. X-ray scanning was not useful because of the uneven moisture distribution in green lumber. After drying the result changes, tracheid-effect and x-ray scanning have good detection ability while RGB color does not provide sufficient information for reliable detection.

  4. Efficient method for events detection in phonocardiographic signals

    NASA Astrophysics Data System (ADS)

    Martinez-Alajarin, Juan; Ruiz-Merino, Ramon

    2005-06-01

    The auscultation of the heart is still the first basic analysis tool used to evaluate the functional state of the heart, as well as the first indicator used to submit the patient to a cardiologist. In order to improve the diagnosis capabilities of auscultation, signal processing algorithms are currently being developed to assist the physician at primary care centers for adult and pediatric population. A basic task for the diagnosis from the phonocardiogram is to detect the events (main and additional sounds, murmurs and clicks) present in the cardiac cycle. This is usually made by applying a threshold and detecting the events that are bigger than the threshold. However, this method usually does not allow the detection of the main sounds when additional sounds and murmurs exist, or it may join several events into a unique one. In this paper we present a reliable method to detect the events present in the phonocardiogram, even in the presence of heart murmurs or additional sounds. The method detects relative maxima peaks in the amplitude envelope of the phonocardiogram, and computes a set of parameters associated with each event. Finally, a set of characteristics is extracted from each event to aid in the identification of the events. Besides, the morphology of the murmurs is also detected, which aids in the differentiation of different diseases that can occur in the same temporal localization. The algorithms have been applied to real normal heart sounds and murmurs, achieving satisfactory results.

  5. A modified agar plate method for detection of Strongyloides stercoralis.

    PubMed

    Koga, K; Kasuya, S; Khamboonruang, C; Sukhavat, K; Ieda, M; Takatsuka, N; Kita, K; Ohtomo, H

    1991-10-01

    The agar plate method is a new technique with high detection rates for coprological diagnosis of human strongyloidiasis. This report details modifications of the technique and establishes a standardized procedure. We recommend that all plates should be carefully observed using a microscope because macroscopic observation can lead to false negative results. It is also advisable to pour formalin solution directly into microscopically positive dishes to collect worms by sedimentation. This procedure enables one to observe worms otherwise hidden. Sealing dishes with adhesive tape prevents larvae from crawling out of the dishes, eliminating any possibility in the reduction of detection rates, and greatly improves the safety conditions for the technician performing the procedure. We consider the agar plate method to be superior to the filter paper method in detecting Strongyloides, and we believe that it will eventually become the technique of choice.

  6. Advances in nucleic acid-based detection methods.

    PubMed Central

    Wolcott, M J

    1992-01-01

    Laboratory techniques based on nucleic acid methods have increased in popularity over the last decade with clinical microbiologists and other laboratory scientists who are concerned with the diagnosis of infectious agents. This increase in popularity is a result primarily of advances made in nucleic acid amplification and detection techniques. Polymerase chain reaction, the original nucleic acid amplification technique, changed the way many people viewed and used nucleic acid techniques in clinical settings. After the potential of polymerase chain reaction became apparent, other methods of nucleic acid amplification and detection were developed. These alternative nucleic acid amplification methods may become serious contenders for application to routine laboratory analyses. This review presents some background information on nucleic acid analyses that might be used in clinical and anatomical laboratories and describes some recent advances in the amplification and detection of nucleic acids. PMID:1423216

  7. Fault detection of gearbox using time-frequency method

    NASA Astrophysics Data System (ADS)

    Widodo, A.; Satrijo, Dj.; Prahasto, T.; Haryanto, I.

    2017-04-01

    This research deals with fault detection and diagnosis of gearbox by using vibration signature. In this work, fault detection and diagnosis are approached by employing time-frequency method, and then the results are compared with cepstrum analysis. Experimental work has been conducted for data acquisition of vibration signal thru self-designed gearbox test rig. This test-rig is able to demonstrate normal and faulty gearbox i.e., wears and tooth breakage. Three accelerometers were used for vibration signal acquisition from gearbox, and optical tachometer was used for shaft rotation speed measurement. The results show that frequency domain analysis using fast-fourier transform was less sensitive to wears and tooth breakage condition. However, the method of short-time fourier transform was able to monitor the faults in gearbox. Wavelet Transform (WT) method also showed good performance in gearbox fault detection using vibration signal after employing time synchronous averaging (TSA).

  8. Compositions and methods for detecting single nucleotide polymorphisms

    DOEpatents

    Yeh, Hsin-Chih; Werner, James; Martinez, Jennifer S.

    2016-11-22

    Described herein are nucleic acid based probes and methods for discriminating and detecting single nucleotide variants in nucleic acid molecules (e.g., DNA). The methods include use of a pair of probes can be used to detect and identify polymorphisms, for example single nucleotide polymorphism in DNA. The pair of probes emit a different fluorescent wavelength of light depending on the association and alignment of the probes when hybridized to a target nucleic acid molecule. Each pair of probes is capable of discriminating at least two different nucleic acid molecules that differ by at least a single nucleotide difference. The methods can probes can be used, for example, for detection of DNA polymorphisms that are indicative of a particular disease or condition.

  9. Comparison of formant detection methods used in speech processing applications

    NASA Astrophysics Data System (ADS)

    Belean, Bogdan

    2013-11-01

    The paper describes time frequency representations of speech signal together with the formant significance in speech processing applications. Speech formants can be used in emotion recognition, sex discrimination or diagnosing different neurological diseases. Taking into account the various applications of formant detection in speech signal, two methods for detecting formants are presented. First, the poles resulted after a complex analysis of LPC coefficients are used for formants detection. The second approach uses the Kalman filter for formant prediction along the speech signal. Results are presented for both approaches on real life speech spectrograms. A comparison regarding the features of the proposed methods is also performed, in order to establish which method is more suitable in case of different speech processing applications.

  10. Radial line method for rear-view mirror distortion detection

    NASA Astrophysics Data System (ADS)

    Rahmah, Fitri; Kusumawardhani, Apriani; Setijono, Heru; Hatta, Agus M.; Irwansyah, .

    2015-01-01

    An image of the object can be distorted due to a defect in a mirror. A rear-view mirror is an important component for the vehicle safety. One of standard parameters of the rear-view mirror is a distortion factor. This paper presents a radial line method for distortion detection of the rear-view mirror. The rear-view mirror was tested for the distortion detection by using a system consisting of a webcam sensor and an image-processing unit. In the image-processing unit, the captured image from the webcam were pre-processed by using smoothing and sharpening techniques and then a radial line method was used to define the distortion factor. It was demonstrated successfully that the radial line method could be used to define the distortion factor. This detection system is useful to be implemented such as in Indonesian's automotive component industry while the manual inspection still be used.

  11. Aerosol detection methods in lidar-based atmospheric profiling

    NASA Astrophysics Data System (ADS)

    Elbakary, Mohamed I.; Iftekharuddin, Khan M.; De Young, Russell; Afrifa, Kwasi

    2016-09-01

    A compact light detection and ranging (LiDAR) system provides aerosols profile measurements by identifying the aerosol scattering ratio as function of the altitude. The aerosol scattering ratios are used to obtain multiple aerosol intensive ratio parameters known as backscatter color ratio, depolarization ratio and lidar ratio. The aerosol ratio parameters are known to vary with aerosol type, size, and shape. Different methods in the literature are employed for detection and classification of aerosol from the measurements. In this paper, a comprehensive review for aerosol detection methods is presented. In addition, results of implemented methods of quantifying aerosols in the atmosphere on real data are compared and presented showing how the backscatter color, depolarization and lidar ratios vary with presence of aerosols in the atmosphere.

  12. Detection of fatigue cracks by nondestructive testing methods

    NASA Technical Reports Server (NTRS)

    Anderson, R. T.; Delacy, T. J.; Stewart, R. C.

    1973-01-01

    The effectiveness was assessed of various NDT methods to detect small tight cracks by randomly introducing fatigue cracks into aluminum sheets. The study included optimizing NDT methods calibrating NDT equipment with fatigue cracked standards, and evaluating a number of cracked specimens by the optimized NDT methods. The evaluations were conducted by highly trained personnel, provided with detailed procedures, in order to minimize the effects of human variability. These personnel performed the NDT on the test specimens without knowledge of the flaw locations and reported on the flaws detected. The performance of these tests was measured by comparing the flaws detected against the flaws present. The principal NDT methods utilized were radiographic, ultrasonic, penetrant, and eddy current. Holographic interferometry, acoustic emission monitoring, and replication methods were also applied on a reduced number of specimens. Generally, the best performance was shown by eddy current, ultrasonic, penetrant and holographic tests. Etching provided no measurable improvement, while proof loading improved flaw detectability. Data are shown that quantify the performances of the NDT methods applied.

  13. Method for predicting peptide detection in mass spectrometry

    DOEpatents

    Kangas, Lars [West Richland, WA; Smith, Richard D [Richland, WA; Petritis, Konstantinos [Richland, WA

    2010-07-13

    A method of predicting whether a peptide present in a biological sample will be detected by analysis with a mass spectrometer. The method uses at least one mass spectrometer to perform repeated analysis of a sample containing peptides from proteins with known amino acids. The method then generates a data set of peptides identified as contained within the sample by the repeated analysis. The method then calculates the probability that a specific peptide in the data set was detected in the repeated analysis. The method then creates a plurality of vectors, where each vector has a plurality of dimensions, and each dimension represents a property of one or more of the amino acids present in each peptide and adjacent peptides in the data set. Using these vectors, the method then generates an algorithm from the plurality of vectors and the calculated probabilities that specific peptides in the data set were detected in the repeated analysis. The algorithm is thus capable of calculating the probability that a hypothetical peptide represented as a vector will be detected by a mass spectrometry based proteomic platform, given that the peptide is present in a sample introduced into a mass spectrometer.

  14. An infrared spectroscopy method to detect ammonia in gastric juice.

    PubMed

    Giovannozzi, Andrea M; Pennecchi, Francesca; Muller, Paul; Balma Tivola, Paolo; Roncari, Silvia; Rossi, Andrea M

    2015-11-01

    Ammonia in gastric juice is considered a potential biomarker for Helicobacter pylori infection and as a factor contributing to gastric mucosal injury. High ammonia concentrations are also found in patients with chronic renal failure, peptic ulcer disease, and chronic gastritis. Rapid and specific methods for ammonia detection are urgently required by the medical community. Here we present a method to detect ammonia directly in gastric juice based on Fourier transform infrared spectroscopy. The ammonia dissolved in biological liquid samples as ammonium ion was released in air as a gas by the shifting of the pH equilibrium of the ammonium/ammonia reaction and was detected in line by a Fourier transform infrared spectroscopy system equipped with a gas cell for the quantification. The method developed provided high sensitivity and selectivity in ammonia detection both in pure standard solutions and in a simulated gastric juice matrix over the range of diagnostic concentrations tested. Preliminary analyses were also performed on real gastric juice samples from patients with gastric mucosal injury and with symptoms of H. pylori infection, and the results were in agreement with the clinicopathology information. The whole analysis, performed in less than 10 min, can be directly applied on the sample without extraction procedures and it ensures high specificity of detection because of the ammonia fingerprint absorption bands in the infrared spectrum. This method could be easily used with endoscopy instrumentation to provide information in real time and would enable the endoscopist to improve and integrate gastroscopic examinations.

  15. Methods of use for sensor based fluid detection devices

    NASA Technical Reports Server (NTRS)

    Lewis, Nathan S. (Inventor)

    2001-01-01

    Methods of use and devices for detecting analyte in fluid. A system for detecting an analyte in a fluid is described comprising a substrate having a sensor comprising a first organic material and a second organic material where the sensor has a response to permeation by an analyte. A detector is operatively associated with the sensor. Further, a fluid delivery appliance is operatively associated with the sensor. The sensor device has information storage and processing equipment, which is operably connected with the device. This device compares a response from the detector with a stored ideal response to detect the presence of analyte. An integrated system for detecting an analyte in a fluid is also described where the sensing device, detector, information storage and processing device, and fluid delivery device are incorporated in a substrate. Methods for use for the above system are also described where the first organic material and a second organic material are sensed and the analyte is detected with a detector operatively associated with the sensor. The method provides for a device, which delivers fluid to the sensor and measures the response of the sensor with the detector. Further, the response is compared to a stored ideal response for the analyte to determine the presence of the analyte. In different embodiments, the fluid measured may be a gaseous fluid, a liquid, or a fluid extracted from a solid. Methods of fluid delivery for each embodiment are accordingly provided.

  16. Statistical method for detecting structural change in the growth process.

    PubMed

    Ninomiya, Yoshiyuki; Yoshimoto, Atsushi

    2008-03-01

    Due to competition among individual trees and other exogenous factors that change the growth environment, each tree grows following its own growth trend with some structural changes in growth over time. In the present article, a new method is proposed to detect a structural change in the growth process. We formulate the method as a simple statistical test for signal detection without constructing any specific model for the structural change. To evaluate the p-value of the test, the tube method is developed because the regular distribution theory is insufficient. Using two sets of tree diameter growth data sampled from planted forest stands of Cryptomeria japonica in Japan, we conduct an analysis of identifying the effect of thinning on the growth process as a structural change. Our results demonstrate that the proposed method is useful to identify the structural change caused by thinning. We also provide the properties of the method in terms of the size and power of the test.

  17. Spectral anomaly methods for aerial detection using KUT nuisance rejection

    NASA Astrophysics Data System (ADS)

    Detwiler, R. S.; Pfund, D. M.; Myjak, M. J.; Kulisek, J. A.; Seifert, C. E.

    2015-06-01

    This work discusses the application and optimization of a spectral anomaly method for the real-time detection of gamma radiation sources from an aerial helicopter platform. Aerial detection presents several key challenges over ground-based detection. For one, larger and more rapid background fluctuations are typical due to higher speeds, larger field of view, and geographically induced background changes. As well, the possible large altitude or stand-off distance variations cause significant steps in background count rate as well as spectral changes due to increased gamma-ray scatter with detection at higher altitudes. The work here details the adaptation and optimization of the PNNL-developed algorithm Nuisance-Rejecting Spectral Comparison Ratios for Anomaly Detection (NSCRAD), a spectral anomaly method previously developed for ground-based applications, for an aerial platform. The algorithm has been optimized for two multi-detector systems; a NaI(Tl)-detector-based system and a CsI detector array. The optimization here details the adaptation of the spectral windows for a particular set of target sources to aerial detection and the tailoring for the specific detectors. As well, the methodology and results for background rejection methods optimized for the aerial gamma-ray detection using Potassium, Uranium and Thorium (KUT) nuisance rejection are shown. Results indicate that use of a realistic KUT nuisance rejection may eliminate metric rises due to background magnitude and spectral steps encountered in aerial detection due to altitude changes and geographically induced steps such as at land-water interfaces.

  18. Method for registration of solar cosmic rays by detecting neutrons

    SciTech Connect

    Andreev, A. V.; Mordovskoy, M. V. Skorkin, V. M.

    2016-12-15

    We consider a method of detecting the ionizing component of solar cosmic rays (SCRs) with energy from tens of MeV to tens of GeV by measuring the energy loss of SCR protons and light nuclei in scintillators and the multiplicity of the local neutron generation in a converter. Scintillation detectors based on stilbene, lithium glass, and solid-state photomultiplier tubes are capable of detecting fast neutrons with a temporal resolution of 10 ns and rejecting the gamma-ray background in the measuring system. The method will allow investigating the nucleon components of primary SCRs in circumterrestrial space.

  19. Method for registration of solar cosmic rays by detecting neutrons

    NASA Astrophysics Data System (ADS)

    Andreev, A. V.; Mordovskoy, M. V.; Skorkin, V. M.

    2016-12-01

    We consider a method of detecting the ionizing component of solar cosmic rays (SCRs) with energy from tens of MeV to tens of GeV by measuring the energy loss of SCR protons and light nuclei in scintillators and the multiplicity of the local neutron generation in a converter. Scintillation detectors based on stilbene, lithium glass, and solid-state photomultiplier tubes are capable of detecting fast neutrons with a temporal resolution of 10 ns and rejecting the gamma-ray background in the measuring system. The method will allow investigating the nucleon components of primary SCRs in circumterrestrial space.

  20. Method for detection of hydrogen peroxide in HT22 cells

    PubMed Central

    Jacewicz, Dagmara; Siedlecka-Kroplewska, Kamila; Drzeżdżon, Joanna; Piotrowska, Agnieszka; Wyrzykowski, Dariusz; Tesmar, Aleksandra; Żamojć, Krzysztof; Chmurzyński, Lech

    2017-01-01

    We have proposed a new method which can be applied in assessing the intracellular production of hydrogen peroxide. Using this assay we have examined the hydrogen peroxide generation during the L-glutamate induced oxidative stress in the HT22 hippocampal cells. The detection of hydrogen peroxide is based on two crucial reagents cis-[Cr(C2O4)(pm)(OH2)2]+ (pm denotes pyridoxamine) and 2-ketobutyrate. The results obtained indicate that the presented method can be a promising tool to detect hydrogen peroxide in biological samples, particularly in cellular experimental models. PMID:28358356

  1. Preface to the Focus Issue: Chaos Detection Methods and Predictability

    SciTech Connect

    Gottwald, Georg A.; Skokos, Charalampos

    2014-06-01

    This Focus Issue presents a collection of papers originating from the workshop Methods of Chaos Detection and Predictability: Theory and Applications held at the Max Planck Institute for the Physics of Complex Systems in Dresden, June 17–21, 2013. The main aim of this interdisciplinary workshop was to review comprehensively the theory and numerical implementation of the existing methods of chaos detection and predictability, as well as to report recent applications of these techniques to different scientific fields. The collection of twelve papers in this Focus Issue represents the wide range of applications, spanning mathematics, physics, astronomy, particle accelerator physics, meteorology and medical research. This Preface surveys the papers of this Issue.

  2. Video meteor detection filtering using soft computing methods

    NASA Astrophysics Data System (ADS)

    Silađi, E.; Vida, D.; Nyarko, K.

    2015-01-01

    In this paper we present the current progress and results from the filtering of Croatian Meteor Network video meteor detections using soft computing methods such as neural networks and support vector machines (SVMs). The goal is to minimize the number of false-positives while preserving the real meteor detections. This is achieved by pre-processing the data to extract meteor movement parameters and then recognizing patterns distinct to meteors. The input data format is fully compliant with the CAMS meteor data standard, and as such the proposed method could be utilized by other meteor networks of the similar kind.

  3. Approach to evaluating leak detection methods in underground storage tanks

    NASA Astrophysics Data System (ADS)

    Starr, J.; Broscious, J.; Niaki, S.

    1986-10-01

    The detection and evaluation of leaks in underground storage tanks require a detailed knowledge of conditions both within the tank and in the nearby surroundings. The test apparatus, as constructed, enables data regarding these environmental conditions to be readily obtained and incorporated in a carefully structured test program that minimizes the amount of costly full-scale testing that would otherwise be required to evaluate volumetric leak detection methods for underground storage tanks. In addition, sufficient flexibility has been designed into the apparatus to enable additional evaluations of non-volumetric test methods to be conducted, and different types of tanks and products to be tested in a cost-effective manner.

  4. Preface to the Focus Issue: chaos detection methods and predictability.

    PubMed

    Gottwald, Georg A; Skokos, Charalampos

    2014-06-01

    This Focus Issue presents a collection of papers originating from the workshop Methods of Chaos Detection and Predictability: Theory and Applications held at the Max Planck Institute for the Physics of Complex Systems in Dresden, June 17-21, 2013. The main aim of this interdisciplinary workshop was to review comprehensively the theory and numerical implementation of the existing methods of chaos detection and predictability, as well as to report recent applications of these techniques to different scientific fields. The collection of twelve papers in this Focus Issue represents the wide range of applications, spanning mathematics, physics, astronomy, particle accelerator physics, meteorology and medical research. This Preface surveys the papers of this Issue.

  5. The advance of non-invasive detection methods in osteoarthritis

    NASA Astrophysics Data System (ADS)

    Dai, Jiao; Chen, Yanping

    2011-06-01

    Osteoarthritis (OA) is one of the most prevalent chronic diseases which badly affected the patients' living quality and economy. Detection and evaluation technology can provide basic information for early treatment. A variety of imaging methods in OA were reviewed, such as conventional X-ray, computed tomography (CT), ultrasound (US), magnetic resonance imaging (MRI) and near-infrared spectroscopy (NIRS). Among the existing imaging modalities, the spatial resolution of X-ray is extremely high; CT is a three-dimensional method, which has high density resolution; US as an evaluation method of knee OA discriminates lesions sensitively between normal cartilage and degenerative one; as a sensitive and nonionizing method, MRI is suitable for the detection of early OA, but the cost is too expensive for routine use; NIRS is a safe, low cost modality, and is also good at detecting early stage OA. In a word, each method has its own advantages, but NIRS is provided with broader application prospect, and it is likely to be used in clinical daily routine and become the golden standard for diagnostic detection.

  6. Methods for Detection of Mitochondrial and Cellular Reactive Oxygen Species

    PubMed Central

    Harrison, David G.

    2014-01-01

    Abstract Significance: Mitochondrial and cellular reactive oxygen species (ROS) play important roles in both physiological and pathological processes. Different ROS, such as superoxide (O2•−), hydrogen peroxide, and peroxynitrite (ONOO•−), stimulate distinct cell-signaling pathways and lead to diverse outcomes depending on their amount and subcellular localization. A variety of methods have been developed for ROS detection; however, many of these methods are not specific, do not allow subcellular localization, and can produce artifacts. In this review, we will critically analyze ROS detection and present advantages and the shortcomings of several available methods. Recent Advances: In the past decade, a number of new fluorescent probes, electron-spin resonance approaches, and immunoassays have been developed. These new state-of-the-art methods provide improved selectivity and subcellular resolution for ROS detection. Critical Issues: Although new methods for HPLC superoxide detection, application of fluorescent boronate-containing probes, use of cell-targeted hydroxylamine spin probes, and immunospin trapping have been available for several years, there has been lack of translation of these into biomedical research, limiting their widespread use. Future Directions: Additional studies to translate these new technologies from the test tube to physiological applications are needed and could lead to a wider application of these approaches to study mitochondrial and cellular ROS. Antioxid. Redox Signal. 20, 372–382. PMID:22978713

  7. Foodproof Salmonella Detection Kit. Performance Tested Method 120301.

    PubMed

    Lindhardt, Charlotte; Schönenbrücher, Holger; Slaghuis, Jörg; Bubert, Andreas; Ossmer, Rolf; Junge, Benjamin; Berghof-Jäger, Kornelia

    2009-01-01

    The foodproof Salmonella Detection Kit was previously validated in the Performance Tested Methods program for the detection of Salmonella species in a variety of foods, including milk powder, egg powder, coconut, cocoa powder, chicken breast, minced meat, sliced sausage, sausage, smoked fish, pasta, white pepper, cumin, dough, wet pet food, dry pet food, ice cream, watermelon, sliced cabbage, food dye, and milk chocolate. The method was shown to be equivalent to the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) and the U.S. Department of Agriculture, Food Safety and Inspection Service's Microbiology Laboratory Guidebook reference culture procedures. In the first Emergency Response Validation (ERV) extension study, peanut butter was inoculated with S. enterica. ser Typhimurium. For the low inoculation level (1.08 CFU/25 g), a Chi-square value of 2.25 indicated that there was no significant performance difference between the foodproof Salmonella Detection Kit and the FDA-BAM reference method. For high-level inoculation (11.5 CFU/25 g) and uninoculated control, there was 100% agreement between the methods. In the second ERV extension study, peanut butter was inoculated with S. enterica. ser Typhimurium. For both inoculation levels (0.1 and 0.5 CFU/25 g by most probable number), Chi-square values of 0 indicated that there was no significant performance difference between foodproof Salmonella Detection Kit and the FDA-BAM reference method.

  8. Recent developments in optical detection methods for microchip separations.

    PubMed

    Götz, Sebastian; Karst, Uwe

    2007-01-01

    This paper summarizes the features and performances of optical detection systems currently applied in order to monitor separations on microchip devices. Fluorescence detection, which delivers very high sensitivity and selectivity, is still the most widely applied method of detection. Instruments utilizing laser-induced fluorescence (LIF) and lamp-based fluorescence along with recent applications of light-emitting diodes (LED) as excitation sources are also covered in this paper. Since chemiluminescence detection can be achieved using extremely simple devices which no longer require light sources and optical components for focusing and collimation, interesting approaches based on this technique are presented, too. Although UV/vis absorbance is a detection method that is commonly used in standard desktop electrophoresis and liquid chromatography instruments, it has not yet reached the same level of popularity for microchip applications. Current applications of UV/vis absorbance detection to microchip separations and innovative approaches that increase sensitivity are described. This article, which contains 85 references, focuses on developments and applications published within the last three years, points out exciting new approaches, and provides future perspectives on this field.

  9. Detecting communities in networks using a Bayesian nonparametric method

    NASA Astrophysics Data System (ADS)

    Hu, Shengze; Wang, Zhenwen

    2014-07-01

    In the real world, a large amount of systems can be described by networks where nodes represent entities and edges the interconnections between them. Community structure in networks is one of the interesting properties revealed in the study of networks. Many methods have been developed to extract communities from networks using the generative models which give the probability of generating networks based on some assumption about the communities. However, many generative models require setting the number of communities in the network. The methods based on such models are lack of practicality, because the number of communities is unknown before determining the communities. In this paper, the Bayesian nonparametric method is used to develop a new community detection method. First, a generative model is built to give the probability of generating the network and its communities. Next, the model parameters and the number of communities are calculated by fitting the model to the actual network. Finally, the communities in the network can be determined using the model parameters. In the experiments, we apply the proposed method to the synthetic and real-world networks, comparing with some other community detection methods. The experimental results show that the proposed method is efficient to detect communities in networks.

  10. An accurate fuzzy edge detection method using wavelet details subimages

    NASA Astrophysics Data System (ADS)

    Sedaghat, Nafiseh; Pourreza, Hamidreza

    2010-02-01

    Edge detection is a basic and important subject in computer vision and image processing. An edge detector is defined as a mathematical operator of small spatial extent that responds in some way to these discontinuities, usually classifying every image pixel as either belonging to an edge or not. Many researchers have been spent attempting to develop effective edge detection algorithms. Despite this extensive research, the task of finding the edges that correspond to true physical boundaries remains a difficult problem.Edge detection algorithms based on the application of human knowledge show their flexibility and suggest that the use of human knowledge is a reasonable alternative. In this paper we propose a fuzzy inference system with two inputs: gradient and wavelet details. First input is calculated by Sobel operator and the second is calculated by wavelet transform of input image and then reconstruction of image only with details subimages by inverse wavelet transform. There are many fuzzy edge detection methods, but none of them utilize wavelet transform as it is used in this paper. For evaluating our method, we detect edges of images with different brightness characteristics and compare results with canny edge detector. The results show the high performance of our method in finding true edges.

  11. A new ultrasonic signal amplification method for detection of bacteria

    NASA Astrophysics Data System (ADS)

    Kant Shukla, Shiva; Resa López, Pablo; Sierra Sánchez, Carlos; Urréjola, José; Segura, Luis Elvira

    2012-10-01

    A new method is presented that increases the sensitivity of ultrasound-based techniques for detection of bacteria. The technique was developed for the detection of catalase-positive microorganisms. It uses a bubble trapping medium containing hydrogen peroxide that is mixed with the sample for microbiological evaluation. The enzyme catalase is present in catalase-positive bacteria, which induces a rapid hydrolysis of hydrogen peroxide, forming bubbles which remain in the medium. This reaction results in the amplification of the mechanical changes that the microorganisms produce in the medium. The effect can be detected by means of ultrasonic wave amplitude continuous measurement since the bubbles increase the ultrasonic attenuation significantly. It is shown that microorganism concentrations of the order of 105 cells ml-1 can be detected using this method. This allows an improvement of three orders of magnitude in the ultrasonic detection threshold of microorganisms in conventional culture media, and is competitive with modern rapid microbiological methods. It can also be used for the characterization of the enzymatic activity.

  12. Comparison of different methods of detection of enteric pathogenic protozoa.

    PubMed

    Ahmed, N H; Chowdhary, A

    2013-01-01

    The study was conducted to compare different methods of detection of pathogenic protozoan parasites in stool specimens of People Living with HIV/AIDS (PLHA). Stool specimens of 242 HIV sero-positive patients were examined using the wet mount technique, modified Ziehl-Neelsen's (ZN) staining, auto-fluorescence and auramine fluorescence staining. Patient specimens, 94 and 40 out of 242, were also subjected to Giardia antigen detection using an enzyme immunoassay and Cryptosporidium antigen detection by immuno-chromatography, respectively. For calculation of sensitivity, specificity, positive and negative predictive values, light microscopy of wet mounts and modified ZN stained smears for Giardia and Coccidia, respectively, were considered as gold standards. Sensitivity of auto-fluorescence, auramine-O staining and antigen detection techniques was found to be 100% as compared to the routine standards. The specificity of auto-fluorescence was 90.6% and 100% for Cyclospora and Isospora, respectively; that of auramine-O staining was 98.9% for Cryptosporidium, 99.30% for Cyclospora and 100% for Isospora; and that of antigen detection was 90.6% and 97.7% for Cryptosporidium and Giardia, respectively. In laboratories requiring screening of large number of stool specimens for detection of protozoan parasites, fluorescence microscopy and antigen detection can be useful techniques. Confirmation of positive results, however, needs to be done with the standard techniques.

  13. Method and apparatus for detecting laminar flow separation and reattachment

    NASA Technical Reports Server (NTRS)

    Stack, John P. (Inventor); Mangalam, Sivaramakrishnan M. (Inventor)

    1989-01-01

    The invention is a method and apparatus for detecting laminar flow separation and flow reattachment of a fluid stream by simultaneously sensing and comparing a plurality of output signals, each representing the dynamic shear stress at one of an equal number of sensors spaced along a straight line on the surface of an airfoil or the like that extends parallel to the fluid stream. The output signals are concurrently compared to detect the sensors across which a reversal in phase of said output signal occurs, said detected sensors being in the region of laminar separation or reattachment. The novelty in this invention is the discovery and use of the phase reversal phenomena to detect laminar separation and attachment of a fluid stream from any surface such as an airfoil supported therein.

  14. Apparatus and method for noninvasive particle detection using doppler spectroscopy

    DOEpatents

    Sinha, Dipen N.

    2016-05-31

    An apparatus and method for noninvasively detecting the presence of solid particulate matter suspended in a fluid flowing through a pipe or an oil and gas wellbore are described. Fluid flowing through a conduit containing the particulate solids is exposed to a fixed frequency (>1 MHz) of ultrasonic vibrations from a transducer attached to the outside of the pipe. The returning Doppler frequency shifted signal derived from the scattering of sound from the moving solid particles is detected by an adjacent transducer. The transmitted signal and the Doppler signal are combined to provide sensitive particulate detection. The magnitude of the signal and the Doppler frequency shift are used to determine the particle size distribution and the velocity of the particles. Measurement of the phase shift between the applied frequency and the detected Doppler shifted may be used to determine the direction of motion of the particles.

  15. Detection of coliform organisms in drinking water by radiometric method.

    PubMed

    Khurshid, S J; Bibi, S

    1991-07-01

    The radiometric method has been used for detection of coliform bacteria in water. The method is based on measuring the released metabolic 14CO2 from 14C-lactose in growth media containing coliform organisms incubated at 37 degrees C under continuous shaking. This rapid and sensitive radiometric method permits the detection of even single coliform organisms within 6 hours of incubation. Using this automated method, a total of 102 samples (in duplicate) collected from different areas in and around Rawalpindi and Islamabad were assessed for coliform bacteria. Of these 102 samples, 50 were tap water samples, 40 from wells and 6 each were from Rawal and Simly dams. About 47% and 67% tap water samples, while 62% and 74% well water samples were found unsatisfactory from around Islamabad and Rawalpindi areas, respectively. About 83% and 66% water samples from Rawal dam and Simly dam respectively were found to be unsatisfactory.

  16. Emergency First Responders' Experience with Colorimetric Detection Methods

    SciTech Connect

    Sandra L. Fox; Keith A. Daum; Carla J. Miller; Marnie M. Cortez

    2007-10-01

    Nationwide, first responders from state and federal support teams respond to hazardous materials incidents, industrial chemical spills, and potential weapons of mass destruction (WMD) attacks. Although first responders have sophisticated chemical, biological, radiological, and explosive detectors available for assessment of the incident scene, simple colorimetric detectors have a role in response actions. The large number of colorimetric chemical detection methods available on the market can make the selection of the proper methods difficult. Although each detector has unique aspects to provide qualitative or quantitative data about the unknown chemicals present, not all detectors provide consistent, accurate, and reliable results. Included here, in a consumer-report-style format, we provide “boots on the ground” information directly from first responders about how well colorimetric chemical detection methods meet their needs in the field and how they procure these methods.

  17. Error Analysis of Reaction Wheel Speed Detection Methods

    NASA Astrophysics Data System (ADS)

    Oh, Shi-Hwan; Lee, Hye-Jin; Lee, Seon-Ho; Yong, Ki-Lyuk

    2008-12-01

    Reaction wheel is one of the actuators for spacecraft attitude control, which generates torque by changing an inertial rotor speed inside of the wheel. In order to generate required torque accurately and estimate an accurate angular momentum, wheel speed should be measured as close to the actual speed as possible. In this study, two conventional speed detection methods for high speed motor with digital tacho pulse (Elapsed-time method and Pulse-count method) and their resolutions are analyzed. For satellite attitude maneuvering and control, reaction wheel shall be operated in bi-directional and low speed operation is sometimes needed for emergency case. Thus the bias error at low speed with constant acceleration (or deceleration) is also analysed. As a result, the speed detection error of elapsed-time method is largely influenced upon the high-speed clock frequency at high speed and largely effected on the number of tacho pulses used in elapsed time calculation at low speed, respectively.

  18. Method for detecting an image of an object

    DOEpatents

    Chapman, Leroy Dean; Thomlinson, William C.; Zhong, Zhong

    1999-11-16

    A method for detecting an absorption, refraction and scatter image of an object by independently analyzing, detecting, digitizing, and combining images acquired on a high and a low angle side of a rocking curve of a crystal analyzer. An x-ray beam which is generated by any suitable conventional apparatus can be irradiated upon either a Bragg type crystal analyzer or a Laue type crystal analyzer. Images of the absorption, refraction and scattering effects are detected, such as on an image plate, and then digitized. The digitized images are simultaneously solved, preferably on a pixel-by-pixel basis, to derive a combined visual image which has dramatically improved contrast and spatial resolution over an image acquired through conventional radiology methods.

  19. Rapid qualitative method for detecting staphylococcal nuclease in foods.

    PubMed Central

    Koupal, A; Deibel, R H

    1978-01-01

    A rapid method for the detection of heat-stable staphylococcal nuclease in foods is described. The procedure consists of an acid precipitation, boiling, and centrifugation followed by enzyme detection in an agar plate containing deoxyribonucleic acid. To test the efficacy of the procedure, purified Staphylococcus aureus nuclease was added to various foods and recovery experiments were performed. Additionally, foods were inoculated and incubated with S. aureus, and the staphylococcal counts were compared with nuclease activity. The results indicate that the procedure possesses merit for a rapid method that can be incorporated into quality control programs. The procedure requires approximately 2.5 h, and it will detect nuclease levels as low as 10 ng/g of food. Images PMID:677882

  20. Methods for gas detection using stationary hyperspectral imaging sensors

    DOEpatents

    Conger, James L [San Ramon, CA; Henderson, John R [Castro Valley, CA

    2012-04-24

    According to one embodiment, a method comprises producing a first hyperspectral imaging (HSI) data cube of a location at a first time using data from a HSI sensor; producing a second HSI data cube of the same location at a second time using data from the HSI sensor; subtracting on a pixel-by-pixel basis the second HSI data cube from the first HSI data cube to produce a raw difference cube; calibrating the raw difference cube to produce a calibrated raw difference cube; selecting at least one desired spectral band based on a gas of interest; producing a detection image based on the at least one selected spectral band and the calibrated raw difference cube; examining the detection image to determine presence of the gas of interest; and outputting a result of the examination. Other methods, systems, and computer program products for detecting the presence of a gas are also described.

  1. Phase-resolved ferromagnetic resonance using heterodyne detection method

    PubMed Central

    Yoon, Seungha; Liu, Jason; McMichael, Robert D.

    2016-01-01

    This paper describes a phase-resolved ferromagnetic resonance (FMR) measurement using a heterodyne method. Spin precession is driven by microwave fields and detected by 1550 nm laser light that is modulated at a frequency slightly shifted with respected to the FMR driving frequency. The evolving phase difference between the spin precession and the modulated light produces a slowly oscillating Kerr rotation signal with a phase equal to the precession phase plus a phase due to the path length difference between the excitation microwave signal and the optical signal. We estimate the accuracy of the precession phase measurement to be 0.1 rad. This heterodyne FMR detection method eliminates the need for field modulation and allows a stronger detection signal at higher intermediate frequency where the 1/f noise floor is reduced. PMID:27453957

  2. Microbial detection method based on sensing molecular hydrogen

    NASA Technical Reports Server (NTRS)

    Wilkins, J. R.; Stoner, G. E.; Boykin, E. H.

    1974-01-01

    A simple method for detecting bacteria, based on the time of hydrogen evolution, was developed and tested against various members of the Enterobacteriaceae group. The test system consisted of (1) two electrodes, platinum and a reference electrode, (2) a buffer amplifier, and (3) a strip-chart recorder. Hydrogen evolution was measured by an increase in voltage in the negative (cathodic) direction. A linear relationship was established between inoculum size and the time hydrogen was detected (lag period). Lag times ranged from 1 h for 1 million cells/ml to 7 h for 1 cell/ml. For each 10-fold decrease in inoculum, length of the lag period increased 60 to 70 min. Based on the linear relationship between inoculum and lag period, these results indicate the potential application of the hydrogen-sensing method for rapidly detecting coliforms and other gas-producing microorganisms in a variety of clinical, food, and other samples.

  3. Microbial detection method based on sensing molecular hydrogen

    NASA Technical Reports Server (NTRS)

    Wilkins, J. R.; Stoner, G. E.; Boykin, E. H.

    1974-01-01

    A simple method for detecting bacteria, based on the time of hydrogen evolution, was developed and tested against various members of the Enterobacteriaceae group. The test system consisted of (1) two electrodes, platinum and a reference electrode, (2) a buffer amplifier, and (3) a strip-chart recorder. Hydrogen evolution was measured by an increase in voltage in the negative (cathodic) direction. A linear relationship was established between inoculum size and the time hydrogen was detected (lag period). Lag times ranged from 1 h for 1 million cells/ml to 7 h for 1 cell/ml. For each 10-fold decrease in inoculum, length of the lag period increased 60 to 70 min. Based on the linear relationship between inoculum and lag period, these results indicate the potential application of the hydrogen-sensing method for rapidly detecting coliforms and other gas-producing microorganisms in a variety of clinical, food, and other samples.

  4. A hybrid approach for efficient anomaly detection using metaheuristic methods.

    PubMed

    Ghanem, Tamer F; Elkilani, Wail S; Abdul-Kader, Hatem M

    2015-07-01

    Network intrusion detection based on anomaly detection techniques has a significant role in protecting networks and systems against harmful activities. Different metaheuristic techniques have been used for anomaly detector generation. Yet, reported literature has not studied the use of the multi-start metaheuristic method for detector generation. This paper proposes a hybrid approach for anomaly detection in large scale datasets using detectors generated based on multi-start metaheuristic method and genetic algorithms. The proposed approach has taken some inspiration of negative selection-based detector generation. The evaluation of this approach is performed using NSL-KDD dataset which is a modified version of the widely used KDD CUP 99 dataset. The results show its effectiveness in generating a suitable number of detectors with an accuracy of 96.1% compared to other competitors of machine learning algorithms.

  5. A hybrid approach for efficient anomaly detection using metaheuristic methods

    PubMed Central

    Ghanem, Tamer F.; Elkilani, Wail S.; Abdul-kader, Hatem M.

    2014-01-01

    Network intrusion detection based on anomaly detection techniques has a significant role in protecting networks and systems against harmful activities. Different metaheuristic techniques have been used for anomaly detector generation. Yet, reported literature has not studied the use of the multi-start metaheuristic method for detector generation. This paper proposes a hybrid approach for anomaly detection in large scale datasets using detectors generated based on multi-start metaheuristic method and genetic algorithms. The proposed approach has taken some inspiration of negative selection-based detector generation. The evaluation of this approach is performed using NSL-KDD dataset which is a modified version of the widely used KDD CUP 99 dataset. The results show its effectiveness in generating a suitable number of detectors with an accuracy of 96.1% compared to other competitors of machine learning algorithms. PMID:26199752

  6. Apparatus and method for detecting leaks in piping

    DOEpatents

    Trapp, D.J.

    1994-12-27

    A method and device are disclosed for detecting the location of leaks along a wall or piping system, preferably in double-walled piping. The apparatus comprises a sniffer probe, a rigid cord such as a length of tube attached to the probe on one end and extending out of the piping with the other end, a source of pressurized air and a source of helium. The method comprises guiding the sniffer probe into the inner pipe to its distal end, purging the inner pipe with pressurized air, filling the annulus defined between the inner and outer pipe with helium, and then detecting the presence of helium within the inner pipe with the probe as is pulled back through the inner pipe. The length of the tube at the point where a leak is detected determines the location of the leak in the pipe. 2 figures.

  7. Apparatus and method for detecting leaks in piping

    DOEpatents

    Trapp, Donald J.

    1994-01-01

    A method and device for detecting the location of leaks along a wall or piping system, preferably in double-walled piping. The apparatus comprises a sniffer probe, a rigid cord such as a length of tube attached to the probe on one end and extending out of the piping with the other end, a source of pressurized air and a source of helium. The method comprises guiding the sniffer probe into the inner pipe to its distal end, purging the inner pipe with pressurized air, filling the annulus defined between the inner and outer pipe with helium, and then detecting the presence of helium within the inner pipe with the probe as is pulled back through the inner pipe. The length of the tube at the point where a leak is detected determines the location of the leak in the pipe.

  8. Proposal generation method for object detection in infrared image

    NASA Astrophysics Data System (ADS)

    Sun, Ning; Jiang, Feng; Yan, Hengchao; Liu, Jixin; Han, Guang

    2017-03-01

    In an infrared image, there is a significant difference between the region of the interested object and its surrounding background. Based on this observation, we propose an effective and efficient proposal generation method which uses a Multi-layer and Multi-size Superpixel Segmentation (MMSS) scheme for object detection in the infrared image. The SLIC (Simple Linear Iterative Clustering) algorithm is applied to partition an infrared image into multi-layer and multi-size superpixels. In each layer, only the individual superpixel and the merging of two adjacent superpixels are used to create the candidate pool of object proposals. A superpixel-based center-surround feature is then defined to measure the discrepancy between the region of the proposal and its surrounding background. To evaluate the performance of the MMSS-based method of proposal generation method, we create an Infrared Interested Object Image Dataset (IIOID), in which the infrared images are collected from several benchmarks and the ground-truth of the interested object segmentation is manually labeled. Compared with several state-of-the-art methods of proposal generation on IIOID, the MMSS-based method has overwhelming superiority in detection recall under different Intersection over Union (IoU) thresholds and is convenient for computation. Furthermore, we implement the MMSS-based method as a processing step for pedestrian detection. Experimental results on benchmark infrared pedestrian image dataset show that the detectors with our method of proposal generation method can greatly reduce the number of candidate windows to be detected and also suppress false positives.

  9. A method for detecting complex correlation in time series

    NASA Astrophysics Data System (ADS)

    Alfi, V.; Petri, A.; Pietronero, L.

    2007-06-01

    We propose a new method for detecting complex correlations in time series of limited size. The method is derived by the Spitzer's identity and proves to work successfully on different model processes, including the ARCH process, in which pairs of variables are uncorrelated, but the three point correlation function is non zero. The application to financial data allows to discriminate among dependent and independent stock price returns where standard statistical analysis fails.

  10. A METHOD TO DETECT VIABLE HELICOBACTER PYLORI BACTERIA IN GROUNDWATER

    EPA Science Inventory

    The inability to detect the presence of viable Helicobacter pylori bacteria in environmental waters has hindered the public health community in assessing the role water may playin the transmission of this pathogen. This work describes a cultural enrichment method coupled with an...

  11. DETECTION OF FECAL ENTEROCOCCI USING A REAL TIME PCR METHOD

    EPA Science Inventory

    In spite of their importance in public health, the detection of fecal enterococci is performed via culturing methods that are time consuming and that are subject to inaccuracies that relate to their culturable status. In order to address these problems, a real time PCR (TaqMan) ...

  12. Magnetic Ligation Method for Quantitative Detection of MicroRNAs

    PubMed Central

    Liong, Monty; Im, Hyungsoon; Majmudar, Maulik D.; Aguirre, Aaron D.; Sebas, Matthew; Lee, Hakho; Weissleder, Ralph

    2014-01-01

    A magnetic ligation method is utilized for the detection of microRNAs amongst a complex biological background without polymerase chain reaction or nucleotide modification. The sandwich probes assay can be adapted to analyze a panel of microRNAs associated with cardiovascular diseases in heart tissue samples. PMID:24532323

  13. TESTING METHODS FOR DETECTION OF CRYPTOSPORIDIUM SPP. IN WATER SAMPLES

    EPA Science Inventory

    A large waterborne outbreak of cryptosporidiosis in Milwaukee, Wisconsin, U.S.A. in 1993 prompted a search for ways to prevent large-scale waterborne outbreaks of protozoan parasitoses. Methods for detecting Cryptosporidium parvum play an integral role in strategies that lead to...

  14. Method for immunodiagnostic detection of dioxins at low concentrations

    DOEpatents

    Vanderlaan, Martin; Stanker, Larry H.; Watkins, Bruce E.; Petrovic, Peter; Gorbach, Siegbert

    1995-01-01

    A method is described for the use of monoclonal antibodies in a sensitive immunoassay for halogenated dioxins and dibenzofurans in industrial samples which contain impurities. Appropriate sample preparation and selective enzyme amplification of the immunoassay sensitivity permits detection of dioxin contaminants in industrial or environmental samples at concentrations in the range of a few parts per trillion.

  15. Eddy Current System and Method for Crack Detection

    NASA Technical Reports Server (NTRS)

    Wincheski, Russell A. (Inventor); Simpson, John W. (Inventor)

    2012-01-01

    An eddy current system and method enables detection of sub-surface damage in a cylindrical object. The invention incorporates a dual frequency, orthogonally wound eddy current probe mounted on a stepper motor-controlled scanning system. The system is designed to inspect for outer surface damage from the interior of the cylindrical object.

  16. A novel duplicate images detection method based on PLSA model

    NASA Astrophysics Data System (ADS)

    Liao, Xiaofeng; Wang, Yongji; Ding, Liping; Gu, Jian

    2012-01-01

    Web image search results usually contain duplicate copies. This paper considers the problem of detecting and clustering duplicate images contained in web image search results. Detecting and clustering the duplicate images together facilitates users' viewing. A novel method is presented in this paper to detect and cluster duplicate images by measuring similarity between their topics. More specifically, images are viewed as documents consisting of visual words formed by vector quantizing the affine invariant visual features. Then a statistical model widely used in text domain, the PLSA(Probabilistic Latent Semantic Analysis) model, is utilized to map images into a probabilistic latent semantic space. Because the main content remains unchanged despite small digital alteration, duplicate images will be close to each other in the derived semantic space. Based on this, a simple clustering process can successfully detect duplicate images and cluster them together. Comparing to those methods based on comparison between hash value of visual words, this method is more robust to the visual feature level alteration posed on the images. Experiments demonstrates the effectiveness of this method.

  17. A novel duplicate images detection method based on PLSA model

    NASA Astrophysics Data System (ADS)

    Liao, Xiaofeng; Wang, Yongji; Ding, Liping; Gu, Jian

    2011-12-01

    Web image search results usually contain duplicate copies. This paper considers the problem of detecting and clustering duplicate images contained in web image search results. Detecting and clustering the duplicate images together facilitates users' viewing. A novel method is presented in this paper to detect and cluster duplicate images by measuring similarity between their topics. More specifically, images are viewed as documents consisting of visual words formed by vector quantizing the affine invariant visual features. Then a statistical model widely used in text domain, the PLSA(Probabilistic Latent Semantic Analysis) model, is utilized to map images into a probabilistic latent semantic space. Because the main content remains unchanged despite small digital alteration, duplicate images will be close to each other in the derived semantic space. Based on this, a simple clustering process can successfully detect duplicate images and cluster them together. Comparing to those methods based on comparison between hash value of visual words, this method is more robust to the visual feature level alteration posed on the images. Experiments demonstrates the effectiveness of this method.

  18. A METHOD TO DETECT VIABLE HELICOBACTER PYLORI BACTERIA IN GROUNDWATER

    EPA Science Inventory

    The inability to detect the presence of viable Helicobacter pylori bacteria in environmental waters has hindered the public health community in assessing the role water may playin the transmission of this pathogen. This work describes a cultural enrichment method coupled with an...

  19. DETECTION OF FECAL ENTEROCOCCI USING A REAL TIME PCR METHOD

    EPA Science Inventory

    In spite of their importance in public health, the detection of fecal enterococci is performed via culturing methods that are time consuming and that are subject to inaccuracies that relate to their culturable status. In order to address these problems, a real time PCR (TaqMan) ...

  20. A serological method for detection of Nosema ceranae

    USDA-ARS?s Scientific Manuscript database

    We aimed at developing a new method for detection of the intracellular parasite Nosema ceranae, one of the most economically devastating pathogens of honey bees. For this purpose, we used our new SWP-32 antibody for the development of Enzyme-Linked Immunosorbent Assay (ELISA). We have also compared ...

  1. Monoclonal antibodies and method for detecting dioxins and dibenzofurans

    DOEpatents

    Vanderlaan, Martin; Stanker, Larry H.; Watkins, Bruce E.; Bailey, Nina R.

    1989-01-01

    Compositions of matter are described which include five monoclonal antibodies that react with dioxins and dibenzofurans, and the five hybridomas that produce these monoclonal antibodies. In addition, a method for the use of these antibodies in a sensitive immunoassay for dioxins and dibenzofurans is given, which permits detection of these pollutants in samples at concentrations in the range of a few parts per billion.

  2. TESTING METHODS FOR DETECTION OF CRYPTOSPORIDIUM SPP. IN WATER SAMPLES

    EPA Science Inventory

    A large waterborne outbreak of cryptosporidiosis in Milwaukee, Wisconsin, U.S.A. in 1993 prompted a search for ways to prevent large-scale waterborne outbreaks of protozoan parasitoses. Methods for detecting Cryptosporidium parvum play an integral role in strategies that lead to...

  3. Photo-fission Methods to detect Fissile Materials

    NASA Astrophysics Data System (ADS)

    Johnson, Micah S.; Glenn, A.; Hartouni, E. P.; Sheets, S. A.; Soltz, R. A.; Danagoulian, A.; Korbly, S. E.; Ledoux, R. J.

    2014-09-01

    A mission objective of various national security agencies is to develop systems that can detect fissile material. There are a myriad of researchers at national laboratories, academic institutions, and industry who are investigating various methods to detect fissile materials. These methods are broken down into active or passive detection systems. Examples of active systems include neutron or photon sources to stimulate and/or scatter from materials. Our focus has been to use photons near the fission barrier of various actinides to excite fission modes and measure the correlated and uncorrelated neutrons. We will present and discuss results from recent measurements. We will present the overall results of our effort and discuss some of the open questions. A mission objective of various national security agencies is to develop systems that can detect fissile material. There are a myriad of researchers at national laboratories, academic institutions, and industry who are investigating various methods to detect fissile materials. These methods are broken down into active or passive detection systems. Examples of active systems include neutron or photon sources to stimulate and/or scatter from materials. Our focus has been to use photons near the fission barrier of various actinides to excite fission modes and measure the correlated and uncorrelated neutrons. We will present and discuss results from recent measurements. We will present the overall results of our effort and discuss some of the open questions. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  4. Methods for parasitic protozoans detection in the environmental samples.

    PubMed

    Skotarczak, B

    2009-09-01

    The environmental route of transmission of many parasitic protozoa and their potential for producing large numbers of transmissive stages constitute persistent threats to public and veterinary health. Conventional and new immunological and molecular methods enable to assess the occurrence, prevalence, levels and sources of waterborne protozoa. Concentration, purification, and detection are the three key steps in all methods that have been approved for routine monitoring of waterborne cysts and oocysts. These steps have been optimized to such an extent that low levels of naturally occurring (oo)cysts of protozoan can be efficiently recovered from water. Ten years have passed since the United States Environmental Protection Agency (USEPA) introduced the 1622 and 1623 methods and used them to concentrate and detect the oocysts of Cryptosporidium and cysts of Giardia in water samples. Nevertheless, the methods still need studies and improvements. Pre-PCR processing procedures have been developed and they are still improved to remove or reduce the effects of PCR inhibitors. The progress in molecular methods allows to more precise distinction of species or simultaneous detection of several parasites, however, they are still not routinely used and need standardization. Standardized methods are required to maximize public health surveillance.

  5. Method for detecting unobserved regions in virtual endoscopy system

    NASA Astrophysics Data System (ADS)

    Mori, Kensaku; Hayashi, Yuichiro; Suenaga, Yasuhito; Toriwaki, Jun-ichiro; Hasegawa, Jun-ichi; Katada, Kazuhiro

    2001-05-01

    This paper shows a method for detecting unobserved regions (oversight regions) during fly-through on Virtual Endoscopy System (VES). When a VES is used as a diagnostic tool, e.g., to find colonopolyps, it is very important for doctors to observe the whole target organ without unobserved regions. The proposed method consists of three parts for detecting unobserved regions: (a) recording of observed triangle patches or voxels, (b) calculation of unobserved regions, and (c) display of unobserved regions. First, the system marks triangle patches that are displayed on the screen at each frame as 'observed patches' in the case of the surface rendering. Presented voxels are calculated in the case of the volume rendering. We execute this process for all frames of the fly-through. Then, the method labels those triangle patches or voxels that do not have 'observed' marks as 'unobserved triangle patches or voxels.' We calculate connected 'unobserved' patches or voxels and consider them to be 'unobserved regions.' In the presentation step, the system displays the target organ while coloring unobserved regions. The method also automatically presents each unobserved region by setting the viewpoint and the view direction around the region. We implemented the proposed method in a VES and applied the VES to colon regions. The experimental results showed that the proposed method can detect unobserved regions and display them effectively.

  6. Electrical Detection of Pneumococcus through the Nanoparticle Decoration Method.

    PubMed

    Pyo, Hannah; Lee, Cho Yeon; Kim, Daehee; Kim, Gyuhee; Lee, Sangho; Yun, Wan Soo

    2017-09-02

    A simple method of nanoparticle decoration can be used in the detection of pneumococcus. After the pneumococcal bacteria were captured by an antibody (pneumococcal C-polysaccharide (PnC) antibody) between the interdigitated electrodes, the gold nanoparticles conjugated with the PnC antibodies were let to bind onto an outer membrane of the bacteria. Upon successfully dense decoration, the bacteria surface will become conductive owing to the metal nanoparticles, and a distinctive conductance change between the electrodes can be observed. Since this success ratio, or the probability of the conductance change, reflects the concentration of the analyte, a number of repeated measurements can be used in the quantification of the bacteria. In this way, we have successfully detected S. pneumoniae in the range of 10-10⁸ CFU/mL. The limit of detection in this work is lower than that in the commercial detection kit. We hope that the nanoparticle decoration method will play a role in the facile detection of various bacteria.

  7. New method for face gaze detection in smart television

    NASA Astrophysics Data System (ADS)

    Lee, Won Oh; Kim, Yeong Gon; Shin, Kwang Yong; Nguyen, Dat Tien; Kim, Ki Wan; Park, Kang Ryoung; Oh, Cheon In

    2014-05-01

    Recently, gaze detection-based interfaces have been regarded as the most natural user interface for use with smart televisions (TVs). Past research conducted on gaze detection primarily used near-infrared (NIR) cameras with NIR illuminators. However, these devices are difficult to use with smart TVs; therefore, there is an increasing need for gaze-detection technology that utilizes conventional (visible light) web cameras. Consequently, we propose a new gaze-detection method using a conventional (visible light) web camera. The proposed approach is innovative in the following three ways. First, using user-dependent facial information obtained in an initial calibration stage, an accurate head pose is calculated. Second, using theoretical and generalized models of changes in facial feature positions, horizontal and vertical head poses are calculated. Third, accurate gaze positions on a smart TV can be obtained based on the user-dependent calibration information and the calculated head poses by using a low-cost conventional web camera without an additional device for measuring the distance from the camera to the user. Experimental results indicate that the gaze-detection accuracy of our method on a 60-in. smart TV is 90.5%.

  8. Device and method for detecting sulfur dioxide at high temperatures

    DOEpatents

    West, David L [Oak Ridge, TN; Montgomery, Frederick C [Oak Ridge, TN; Armstrong, Timothy R [Clinton, TN

    2011-11-01

    The present invention relates to a method for selectively detecting and/or measuring gaseous SO.sub.2 at a temperature of at least 500.degree. C., the method involving: (i) providing a SO.sub.2-detecting device including an oxygen ion-conducting substrate having on its surface at least three electrodes comprising a first, second, and third electrode; (ii) driving a starting current of specified magnitude and temporal variation between the first and second electrodes; (iii) contacting the SO.sub.2-detecting device with the SO.sub.2-containing sample while maintaining the magnitude and any temporal variation of the starting current, wherein said SO.sub.2-containing sample causes a change in the electrical conductance of said device; and (iv) detecting the change in electrical conductance of the device based on measuring an electrical property related to or indicative of the conductance of the device between the first and third electrodes, or between the second and third electrodes, and detecting SO.sub.2 in the SO.sub.2-containing sample based on the measured change in electrical conductance.

  9. A novel method for pulmonary embolism detection in CTA images.

    PubMed

    Özkan, Haydar; Osman, Onur; Şahin, Sinan; Boz, Ali Fuat

    2014-03-01

    In this paper, we propose a new computer-aided detection (CAD) - based method to detect pulmonary embolism (PE) in computed tomography angiography images (CTAI). Since lung vessel segmentation is the main objective to provide high sensitivity in PE detection, this method performs accurate lung vessel segmentation. To concatenate clogged vessels due to PEs, the starting region of PEs and some reference points (RPs) are determined. These RPs are detected according to the fixed anatomical structures. After lung vessel tree is segmented, the region, intensity, and size of PEs are used to distinguish them. We used the data sets that have heart disease or abnormal tissues because of lung disease except PE in this work. According to the results, 428 of 450 PEs, labeled by the radiologists from 33 patients, have been detected. The sensitivity of the developed system is 95.1% at 14.4 false positive per data set (FP/ds). With this performance, the proposed CAD system is found quite useful to use as a second reader by the radiologists.

  10. Comparison of methods to detect Pasteurella multocida in carrier waterfowl

    USGS Publications Warehouse

    Samuel, M.D.; Shadduck, D.J.; Goldberg, D.R.; Johnson, W.P.

    2003-01-01

    We conducted laboratory challenge trials using mallard ducks (Anas platyrhynchos) to compare methods for detecting carriers of Pasteurella multocida, the bacterium that causes avian cholera, in wild birds. Birds that survived the initial infection were euthanized at 2-4 wk intervals up to 14 wk post challenge. Isolates of P. multocida were obtained at necropsy from 23% of the birds that survived initial infection. We found that swab samples (oral, cloacal, nasal, eye, and leg joint) were most effective for detecting carrier birds up to 14 wk post infection. No detectable differences in isolation were observed for samples stored in either 10% dimethysulfoxide or brain heart infusion broth. The frequency of detecting carriers in our challenge trials appeared to be related to mortality rates observed during the trial, but was not related to a number of other factors including time after challenge, time delays in collecting tissues postmortem, and route of infection. In our trials, there was little association between antibody levels and carrier status. We concluded that swabs samples collected from recently dead birds, stored in liquid nitrogen, and processed using selective broth provide a feasible field method for detecting P. multocida carriers in wild waterfowl.

  11. An effective method for incoherent scattering radar's detecting ability evaluation

    NASA Astrophysics Data System (ADS)

    Lu, Ziqing; Yao, Ming; Deng, Xiaohua

    2016-06-01

    Ionospheric incoherent scatter radar (ISR), which is used to detect ionospheric electrons and ions, generally, has megawatt class transmission power and hundred meter level antenna aperture. The crucial purpose of this detecting technology is to get ionospheric parameters by acquiring the autocorrelation function and power spectrum of the target ionospheric plasma echoes. Whereas the ISR's echoes are very weak because of the small radar cross section of its target, estimating detecting ability will be significantly instructive and meaningful for ISR system design. In this paper, we evaluate the detecting ability through signal-to-noise ratio (SNR). The soft-target radar equation is deduced to be applicable to ISR, through which we use data from International Reference Ionosphere model to simulate signal-to-noise ratio (SNR) of echoes, and then comparing the measured SNR from European Incoherent Scatter Scientific Association and Advanced Modular Incoherent Scatter Radar with the simulation. The simulation results show good consistency with the measured SNR. For ISR, the topic of this paper is the first comparison between the calculated SNR and radar measurements; the detecting ability can be improved through increasing SNR. The effective method for ISR's detecting ability evaluation provides basis for design of radar system.

  12. A morphological method for ammonia detection in liver

    PubMed Central

    Gutiérrez-de-Juan, Virginia; López de Davalillo, Sergio; Fernández-Ramos, David; Barbier-Torres, Lucía; Zubiete-Franco, Imanol; Fernández-Tussy, Pablo; Simon, Jorge; Lopitz-Otsoa, Fernando; de las Heras, Javier; Iruzubieta, Paula; Arias-Loste, María Teresa; Villa, Erica; Crespo, Javier; Andrade, Raúl; Lucena, M. Isabel; Varela-Rey, Marta; Lu, Shelly C.; Mato, José M.; Delgado, Teresa Cardoso

    2017-01-01

    Hyperammonemia is a metabolic condition characterized by elevated levels of ammonia and a common event in acute liver injury/failure and chronic liver disease. Even though hepatic ammonia levels are potential predictive factors of patient outcome, easy and inexpensive methods aiming at the detection of liver ammonia accumulation in the clinical setting remain unavailable. Thus, herein we have developed a morphological method, based on the utilization of Nessler´s reagent, to accurately and precisely detect the accumulation of ammonia in biological tissue. We have validated our method against a commercially available kit in mouse tissue samples and, by using this modified method, we have confirmed the hepatic accumulation of ammonia in clinical and animal models of acute and chronic advanced liver injury as well as in the progression of fatty liver disease. Overall, we propose a morphological method for ammonia detection in liver that correlates well with the degree of liver disease severity and therefore can be potentially used to predict patient outcome. PMID:28319158

  13. A morphological method for ammonia detection in liver.

    PubMed

    Gutiérrez-de-Juan, Virginia; López de Davalillo, Sergio; Fernández-Ramos, David; Barbier-Torres, Lucía; Zubiete-Franco, Imanol; Fernández-Tussy, Pablo; Simon, Jorge; Lopitz-Otsoa, Fernando; de Las Heras, Javier; Iruzubieta, Paula; Arias-Loste, María Teresa; Villa, Erica; Crespo, Javier; Andrade, Raúl; Lucena, M Isabel; Varela-Rey, Marta; Lu, Shelly C; Mato, José M; Delgado, Teresa Cardoso; Martínez-Chantar, María-Luz

    2017-01-01

    Hyperammonemia is a metabolic condition characterized by elevated levels of ammonia and a common event in acute liver injury/failure and chronic liver disease. Even though hepatic ammonia levels are potential predictive factors of patient outcome, easy and inexpensive methods aiming at the detection of liver ammonia accumulation in the clinical setting remain unavailable. Thus, herein we have developed a morphological method, based on the utilization of Nessler´s reagent, to accurately and precisely detect the accumulation of ammonia in biological tissue. We have validated our method against a commercially available kit in mouse tissue samples and, by using this modified method, we have confirmed the hepatic accumulation of ammonia in clinical and animal models of acute and chronic advanced liver injury as well as in the progression of fatty liver disease. Overall, we propose a morphological method for ammonia detection in liver that correlates well with the degree of liver disease severity and therefore can be potentially used to predict patient outcome.

  14. Detection and isolation of circulating tumor cells: principles and methods.

    PubMed

    Esmaeilsabzali, Hadi; Beischlag, Timothy V; Cox, Michael E; Parameswaran, Ash M; Park, Edward J

    2013-11-15

    Efforts to improve the clinical management of several cancers include finding better methods for the quantitative and qualitative analysis of circulating tumor cells (CTCs). However, detection and isolation of CTCs from the blood circulation is not a trivial task given their scarcity and the lack of reliable markers to identify these cells. With a variety of emerging technologies, a thorough review of the exploited principles and techniques as well as the trends observed in the development of these technologies can assist researchers to recognize the potential improvements and alternative approaches. To help better understand the related biological concepts, a simplified framework explaining cancer formation and its spread to other organs as well as how CTCs contribute to this process has been presented first. Then, based on their basic working-principles, the existing methods for detection and isolation of CTCs have been classified and reviewed as nucleic acid-based, physical properties-based and antibody-based methods. The review of literature suggests that antibody-based methods, particularly in conjunction with a microfluidic lab-on-a-chip setting, offer the highest overall performance for detection and isolation of CTCs. Further biological and engineering-related research is required to improve the existing methods. These include finding more specific markers for CTCs as well as enhancing the throughput, sensitivity, and analytic functionality of current devices.

  15. Optimal method for exoplanet detection by angular differential imaging.

    PubMed

    Mugnier, Laurent M; Cornia, Alberto; Sauvage, Jean-François; Rousset, Gérard; Fusco, Thierry; Védrenne, Nicolas

    2009-06-01

    We propose a novel method for the efficient direct detection of exoplanets from the ground using angular differential imaging. The method combines images appropriately, then uses the combined images jointly in a maximum-likelihood framework to estimate the position and intensity of potential planets orbiting the observed star. It takes into account the mixture of photon and detector noises and a positivity constraint on the planet's intensity. A reasonable detection criterion is also proposed based on the computation of the noise propagation from the images to the estimated intensity of the potential planet. The implementation of this method is tested on simulated data that take into account static aberrations before and after the coronagraph, residual turbulence after adaptive optics correction, and noise.

  16. A method for detecting hydrophobic patches on protein surfaces.

    PubMed

    Lijnzaad, P; Berendsen, H J; Argos, P

    1996-10-01

    A method for the detection of hydrophobic patches on the surfaces of protein tertiary structures is presented. It delineates explicit contiguous pieces of surface of arbitrary size and shape that consist solely of carbon and sulphur atoms using a dot representation of the solvent-accessible surface. The technique is also useful in detecting surface segments with other characteristics, such as polar patches. Its potential as a tool in the study of protein-protein interactions and substrate recognition is demonstrated by applying the method to myoglobin, Leu/IIe/Val-binding protein, lipase, lysozyme, azurin, triose phosphate isomerase, carbonic anhydrase, and phosphoglycerate kinase. Only the largest patches, having sizes exceeding random expectation, are deemed meaningful. In addition to well-known hydrophobic patches on these proteins, a number of other patches are found, and their significance is discussed. The method is simple, fast, and robust. The program text is obtainable by anonymous ftp.

  17. Immunochemical methods for ochratoxin A detection: a review.

    PubMed

    Meulenberg, Eline P

    2012-04-01

    The safety of food and feed depends to a great deal on quality control. Numerous compounds and organisms may contaminate food and feed commodities and thus pose a health risk for consumers. The compound of interest in this review is ochratoxin A (OTA), a secondary metabolite of the fungi Aspergillus and Penicillium. Due to its adverse health effects, detection and quantification are of utmost importance. Quality control of food and feed requires extraction and analysis, including TLC, HPLC, MS, and immunochemical methods. Each of these methods has its advantages and disadvantages. However, with regard to costs and rapidity, immunochemical methods have gained much interest in the last decade. In this review an introduction to immunochemistry and assay design will be given to elucidate the principles. Further, the application of the various formats to the detection and quantification of ochratoxin will be described, including the use of commercially available kits.

  18. Immunochemical Methods for Ochratoxin A Detection: A Review

    PubMed Central

    Meulenberg, Eline P.

    2012-01-01

    The safety of food and feed depends to a great deal on quality control. Numerous compounds and organisms may contaminate food and feed commodities and thus pose a health risk for consumers. The compound of interest in this review is ochratoxin A (OTA), a secondary metabolite of the fungi Aspergillus and Penicillium. Due to its adverse health effects, detection and quantification are of utmost importance. Quality control of food and feed requires extraction and analysis, including TLC, HPLC, MS, and immunochemical methods. Each of these methods has its advantages and disadvantages. However, with regard to costs and rapidity, immunochemical methods have gained much interest in the last decade. In this review an introduction to immunochemistry and assay design will be given to elucidate the principles. Further, the application of the various formats to the detection and quantification of ochratoxin will be described, including the use of commercially available kits. PMID:22606375

  19. A Method for Microcalcifications Detection in Breast Mammograms.

    PubMed

    Alasadi, Abbas H Hassin; Al-Saedi, Ahmed Kadem Hamed

    2017-04-01

    Breast cancer is the most cause of death for women above age 40 around the world. In this paper, we propose a method to detect microcalcifications in digital mammography images using two-dimensional Discrete Wavelets Transform and image enhancement techniques for removing noise as well as to get a better contrast. The initial step is applying a preprocessing techniques to improve the edge of the breast and then segmentation process (Region of interest) for eliminating some regions in the image, which are not useful for the mammography interpretation. Then unsharp masking and histogram modification technique has used to enhance the contrast of the image and to clarify some details like microcalcifications. Lastly, Discrete Wavelets Transform applied for detecting the abnormality. The proposed method has evaluated using the Mammographic Image Analysis Society (AS) mammography databases. The proposed method has achieved acceptable results.

  20. Design of an explosive detection system using Monte Carlo method.

    PubMed

    Hernández-Adame, Pablo Luis; Medina-Castro, Diego; Rodriguez-Ibarra, Johanna Lizbeth; Salas-Luevano, Miguel Angel; Vega-Carrillo, Hector Rene

    2016-11-01

    Regardless the motivation terrorism is the most important risk for the national security in many countries. Attacks with explosives are the most common method used by terrorists. Therefore several procedures to detect explosives are utilized; among these methods are the use of neutrons and photons. In this study the Monte Carlo method an explosive detection system using a (241)AmBe neutron source was designed. In the design light water, paraffin, polyethylene, and graphite were used as moderators. In the work the explosive RDX was used and the induced gamma rays due to neutron capture in the explosive was estimated using NaI(Tl) and HPGe detectors. When light water is used as moderator and HPGe as the detector the system has the best performance allowing distinguishing between the explosive and urea. For the final design the Ambient dose equivalent for neutrons and photons were estimated along the radial and axial axis.

  1. A comparison of change detection methods using multispectral scanner data

    USGS Publications Warehouse

    Seevers, P.M.; Jones, B.K.; Qiu, Zhicheng; Liu, Yutong

    1994-01-01

    Change detection methods were investigated as a cooperative activity between the U.S. Geological Survey and the National Bureau of Surveying and Mapping, People's Republic of China. Subtraction of band 2, band 3, normalized difference vegetation index, and tasseled cap bands 1 and 2 data from two multispectral scanner images were tested using two sites in the United States and one in the People's Republic of China. A new statistical method also was tested. Band 2 subtraction gives the best results for detecting change from vegetative cover to urban development. The statistical method identifies areas that have changed and uses a fast classification algorithm to classify the original data of the changed areas by land cover type present for each image date.

  2. Fault detection in electromagnetic suspension systems with state estimation methods

    SciTech Connect

    Sinha, P.K.; Zhou, F.B.; Kutiyal, R.S. . Dept. of Engineering)

    1993-11-01

    High-speed maglev vehicles need a high level of safety that depends on the whole vehicle system's reliability. There are many ways of attaining high reliability for the system. Conventional method uses redundant hardware with majority vote logic circuits. Hardware redundancy costs more, weigh more and occupy more space than that of analytically redundant methods. Analytically redundant systems use parameter identification and state estimation methods based on the system models to detect and isolate the fault of instruments (sensors), actuator and components. In this paper the authors use the Luenberger observer to estimate three state variables of the electromagnetic suspension system: position (airgap), vehicle velocity, and vertical acceleration. These estimates are compared with the corresponding sensor outputs for fault detection. In this paper, they consider FDI of the accelerometer, the sensor which provides the ride quality.

  3. Molecular Diagnostic Methods for Detection and Characterization of Human Noroviruses

    PubMed Central

    Chen, Haifeng; Hu, Yuan

    2016-01-01

    Human noroviruses are a group of viral agents that afflict people of all age groups. The viruses are now recognized as the most common causative agent of nonbacterial acute gastroenteritis and foodborne viral illness worldwide. However, they have been considered to play insignificant roles in the disease burden of acute gastroenteritis for the past decades until the recent advent of new and more sensitive molecular diagnostic methods. The availability and application of the molecular diagnostic methods have led to enhanced detection of noroviruses in clinical, food and environmental samples, significantly increasing the recognition of noroviruses as an etiologic agent of epidemic and sporadic acute gastroenteritis. This article aims to summarize recent efforts made for the development of molecular methods for the detection and characterization of human noroviruses. PMID:27335620

  4. Comparison of ultraviolet detection and charged aerosol detection methods for liquid-chromatographic determination of protoescigenin.

    PubMed

    Filip, Katarzyna; Grynkiewicz, Grzegorz; Gruza, Mariusz; Jatczak, Kamil; Zagrodzki, Bogdan

    2014-01-01

    Escin, a complex mixture of pentacyclic triterpene saponins obtained from horse chestnut seeds extract (HCSE; Aesculus hippocastanum L.), constitutes a traditional herbal active substance of preparations (drugs) used for a treatment of chronic venous insufficiency and capillary blood vessel leakage. A new approach to exploitation of pharmacological potential of this saponin complex has been recently proposed, in which the β-escin mixture is perceived as a source of a hitherto unavailable raw material, pentacyclic triterpene aglycone-protoescigenin. Although many liquid chromatography methods are described in the literature for saponins determination, analysis of protoescigenin is barely mentioned. In this work, a new ultra-high performance liquid chromatography (UHPLC) method developed for protoescigenin quantification has been described. CAD (charged aerosol detection), as a relatively new detection method based on aerosol charging, has been applied in this method as an alternative to ultraviolet (UV) detection. The influence of individual parameters on CAD response and sensitivity was studied. The detection was performed using CAD and UV (200 nm) simultaneously and the results were compared with reference to linearity, accuracy, precision and limit of detection.

  5. Earth analysis methods, subsurface feature detection methods, earth analysis devices, and articles of manufacture

    DOEpatents

    West, Phillip B.; Novascone, Stephen R.; Wright, Jerry P.

    2011-09-27

    Earth analysis methods, subsurface feature detection methods, earth analysis devices, and articles of manufacture are described. According to one embodiment, an earth analysis method includes engaging a device with the earth, analyzing the earth in a single substantially lineal direction using the device during the engaging, and providing information regarding a subsurface feature of the earth using the analysis.

  6. Earth analysis methods, subsurface feature detection methods, earth analysis devices, and articles of manufacture

    DOEpatents

    West, Phillip B [Idaho Falls, ID; Novascone, Stephen R [Idaho Falls, ID; Wright, Jerry P [Idaho Falls, ID

    2012-05-29

    Earth analysis methods, subsurface feature detection methods, earth analysis devices, and articles of manufacture are described. According to one embodiment, an earth analysis method includes engaging a device with the earth, analyzing the earth in a single substantially lineal direction using the device during the engaging, and providing information regarding a subsurface feature of the earth using the analysis.

  7. Methods for Detecting the Environmental Coccoid Form of Helicobacter pylori

    PubMed Central

    Mazaheri Assadi, Mahnaz; Chamanrokh, Parastoo; Whitehouse, Chris A.; Huq, Anwar

    2015-01-01

    Helicobacter pylori is recognized as the most common pathogen to cause gastritis, peptic and duodenal ulcers, and gastric cancer. The organisms are found in two forms: (1) spiral-shaped bacillus and (2) coccoid. H. pylori coccoid form, generally found in the environment, is the transformed form of the normal spiral-shaped bacillus after exposed to water or adverse environmental conditions such as exposure to sub-inhibitory concentrations of antimicrobial agents. The putative infectious capability and the viability of H. pylori under environmental conditions are controversial. This disagreement is partially due to the fact of lack in detecting the coccoid form of H. pylori in the environment. Accurate and effective detection methods of H. pylori will lead to rapid treatment and disinfection, and less human health damages and reduction in health care costs. In this review, we provide a brief introduction to H. pylori environmental coccoid forms, their transmission, and detection methods. We further discuss the use of these detection methods including their accuracy and efficiency. PMID:26075197

  8. Different diagnostic methods for detection of influenza epidemics.

    PubMed Central

    Rebelo-de-Andrade, H.; Zambon, M. C.

    2000-01-01

    Linking continuous community-based morbidity recording of influenza-like illness (ILI) with virological sampling has consistently proved its value as one of the earliest indicators of circulating influenza activity. The clinical morbidity recording in the Portuguese national surveillance network, during a 7-year period, and the contribution of different diagnostic techniques, including virus isolation, multiplex RT-PCR, immunocapture enzyme linked immunoassay (EIA) and complement fixation tests (CFTs) for the detection of influenza in such a community-based setting is described and evaluated in this study. There was good correlation between the increase of morbidity, total samples taken and the detection of influenza virus by all the methods although this was less evident for virus isolation and EIA than for RT-PCR or serology. From a total of 1685 throat swabs collected from cases of ILI, 43.6% were RT-PCR positive, 17.5% were positive by capture EIA and in 5% virus isolates were made. The detection of influenza by RT-PCR occurred earlier than by any other method and showed the best correlation with epidemic patterns of morbidity registration. We conclude that in surveillance systems where virus culture is sub-optimal, RT-PCR provides a rapid, sensitive, specific method for detecting influenza viruses from community-based sampling. PMID:10982076

  9. Cointegration Methods for Detection and Attribution of Climate Change

    NASA Astrophysics Data System (ADS)

    Turasie, A. A.; Stephenson, D.

    2016-12-01

    Reliable detection and attribution of changes in climate is fundamental to our understanding of climate change and in enabling decision makers to manage climate-related risks [1]. This study aims to address this concern. Regression methods, particularly the Ordinary Least Squares (OLS) and Total Least Square (TLS), have been widely used in this field of climate studies. However, the fact that most of the climatic variables and temperature in particular are non-stationary in the recent years poses a doubt on reliability of these existing methods, which are heavily dependent on stationarity assumption. Cointegration modelling, on the other hand, has got attractive features for modelling non-stationary time series. Three estimates of the scaling factor, namely: the OLS and TLS regression estimates and the Vector Autoregression (VAR) based maximum likelihood estimate (MLE) of cointegrating relations are critically evaluated here in the context of detection-attribution studies. The results, from simulations and real data, have shown that the MLE of cointegration model are less biased, highly efficient and consistent compared to the two existing methods. References:[1] Hegerl G.C., Hoegh-Guldberg O., Casassa G., Hoerling M. P., Kovats R. S., Parmesan C. Pierce D. W. Stott P. A. (2010) Good practice guidance paper on detection and attribution related to anthropogenic climate change. Meeting Report of the IPCC Experts on Detection and Attribution of Anthropogenic Climate Change.

  10. Image change detection systems, methods, and articles of manufacture

    DOEpatents

    Jones, James L.; Lassahn, Gordon D.; Lancaster, Gregory D.

    2010-01-05

    Aspects of the invention relate to image change detection systems, methods, and articles of manufacture. According to one aspect, a method of identifying differences between a plurality of images is described. The method includes loading a source image and a target image into memory of a computer, constructing source and target edge images from the source and target images to enable processing of multiband images, displaying the source and target images on a display device of the computer, aligning the source and target edge images, switching displaying of the source image and the target image on the display device, to enable identification of differences between the source image and the target image.

  11. Cyanoacrylate fuming method for detection of latent fingermarks: a review.

    PubMed

    Bumbrah, Gurvinder Singh

    2017-01-01

    Cyanoacrylate, also called super glue, fuming is a chemical method for the detection of latent fingermarks on non-porous surfaces such as glass, plastic etc. The method relies on the deposition of polymerized cyanoacrylate ester on residues of latent fingermarks. The method develops clear, stable, white colored fingerprints. However, several post-treatement procedures can be used to improve the contrast of developed prints. In addition to it, some pre-treatment procedures can also be used to develop aged latent fingermarks. It is an efficient, non-destrcutive and excellent procedure for developing latent fingermarks.

  12. Methods of detecting and controlling mucoid pseudomonas biofilm production

    NASA Technical Reports Server (NTRS)

    Yu, Hongwei D. (Inventor); Qiu, Dongru (Inventor)

    2010-01-01

    Compositions and methods for detecting and controlling the conversion to mucoidy in Pseudomonas aeruginosa are disclosed. The present invention provides for detecting the switch from nonmucoid to mucoid state of P. aeruginosa by measuring mucE expression or MucE protein levels. The interaction between MucE and AlgW controls the switch to mucoidy in wild type P. aeruginosa. Also disclosed is an alginate biosynthesis heterologous expression system for use in screening candidate substances that inhibit conversion to mucoidy.

  13. Methods of detecting and controlling mucoid Pseudomonas biofilm production

    NASA Technical Reports Server (NTRS)

    Yu, Hongwei D. (Inventor); Qiu, Dongru (Inventor)

    2013-01-01

    Compositions and methods for detecting and controlling the conversion to mucoidy in Pseudomonas aeruginosa are disclosed. The present invention provides for detecting the switch from nonmucoid to mucoid state of P. aeruginosa by measuring mucE expression or MucE protein levels. The interaction between MucE and AlgW controls the switch to mucoidy in wild type P. aeruginosa. Also disclosed is an alginate biosynthesis heterologous expression system for use in screening candidate substances that inhibit conversion to mucoidy.

  14. A new method of edge detection for object recognition

    USGS Publications Warehouse

    Maddox, Brian G.; Rhew, Benjamin

    2004-01-01

    Traditional edge detection systems function by returning every edge in an input image. This can result in a large amount of clutter and make certain vectorization algorithms less accurate. Accuracy problems can then have a large impact on automated object recognition systems that depend on edge information. A new method of directed edge detection can be used to limit the number of edges returned based on a particular feature. This results in a cleaner image that is easier for vectorization. Vectorized edges from this process could then feed an object recognition system where the edge data would also contain information as to what type of feature it bordered.

  15. Dynamic Moire methods for detection of loosened space shuttle tiles

    NASA Astrophysics Data System (ADS)

    Snow, W. L.; Burner, A. W.; Goad, W. K.

    1981-09-01

    Moire fringe methods for detecting loose space shuttle tiles were investigated with a test panel consisting of a loose tile surrounded by four securely bonded tiles. The test panel was excited from 20 to 150 Hz with in-plane sinusoidal acceleration of 2 g (peak). If the shuttle orbiter can be subjected to periodic excitation of 1 to 2 g (peak) and rigid-body periodic displacements do not mask the change in the Moire pattern due to tile looseness, then the use of projected Moire fringes to detect out-of-plane rockin appears to be the most viable indicator of tile looseness since no modifications to the tiles are required.

  16. Rapid Methods for High-Throughput Detection of Sulfoxides▿

    PubMed Central

    Shainsky, Janna; Derry, Netta-Lee; Leichtmann-Bardoogo, Yael; Wood, Thomas K.; Fishman, Ayelet

    2009-01-01

    Enantiopure sulfoxides are prevalent in drugs and are useful chiral auxiliaries in organic synthesis. The biocatalytic enantioselective oxidation of prochiral sulfides is a direct and economical approach for the synthesis of optically pure sulfoxides. The selection of suitable biocatalysts requires rapid and reliable high-throughput screening methods. Here we present four different methods for detecting sulfoxides produced via whole-cell biocatalysis, three of which were exploited for high-throughput screening. Fluorescence detection based on the acid activation of omeprazole was utilized for high-throughput screening of mutant libraries of toluene monooxygenases, but no active variants have been discovered yet. The second method is based on the reduction of sulfoxides to sulfides, with the coupled release and measurement of iodine. The availability of solvent-resistant microtiter plates enabled us to modify the method to a high-throughput format. The third method, selective inhibition of horse liver alcohol dehydrogenase, was used to rapidly screen highly active and/or enantioselective variants at position V106 of toluene ortho-monooxygenase in a saturation mutagenesis library, using methyl-p-tolyl sulfide as the substrate. A success rate of 89% (i.e., 11% false positives) was obtained, and two new mutants were selected. The fourth method is based on the colorimetric detection of adrenochrome, a back-titration procedure which measures the concentration of the periodate-sensitive sulfide. Due to low sensitivity during whole-cell screening, this method was found to be useful only for determining the presence or absence of sulfoxide in the reaction. The methods described in the present work are simple and inexpensive and do not require special equipment. PMID:19465532

  17. Method of Detecting System Function by Measuring Frequency Response

    NASA Technical Reports Server (NTRS)

    Morrison, John L. (Inventor); Morrison, William H. (Inventor)

    2008-01-01

    Real time battery impedance spectrum is acquired using one time record, Compensated Synchronous Detection (CSD). This parallel method enables battery diagnostics. The excitation current to a test battery is a sum of equal amplitude sin waves of a few frequencies spread over range of interest. The time profile of this signal has duration that is a few periods of the lowest frequency. The voltage response of the battery, average deleted, is the impedance of the battery in the time domain. Since the excitation frequencies are known, synchronous detection processes the time record and each component, both magnitude and phase, is obtained. For compensation, the components, except the one of interest, are reassembled in the time domain. The resulting signal is subtracted from the original signal and the component of interest is synchronously detected. This process is repeated for each component.

  18. Method for detecting a mass density image of an object

    DOEpatents

    Wernick, Miles N.; Yang, Yongyi

    2008-12-23

    A method for detecting a mass density image of an object. An x-ray beam is transmitted through the object and a transmitted beam is emitted from the object. The transmitted beam is directed at an angle of incidence upon a crystal analyzer. A diffracted beam is emitted from the crystal analyzer onto a detector and digitized. A first image of the object is detected from the diffracted beam emitted from the crystal analyzer when positioned at a first angular position. A second image of the object is detected from the diffracted beam emitted from the crystal analyzer when positioned at a second angular position. A refraction image is obtained and a regularized mathematical inversion algorithm is applied to the refraction image to obtain a mass density image.

  19. Workshop Targets Development of Geodetic Transient Detection Methods

    NASA Astrophysics Data System (ADS)

    Murray-Moraleda, Jessica R.; Lohman, Rowena

    2010-02-01

    2009 SCEC Annual Meeting: Workshop on Transient Anomalous Strain Detection; Palm Springs, California, 12-13 September 2009; The Southern California Earthquake Center (SCEC) is a community of researchers at institutions worldwide working to improve understanding of earthquakes and mitigate earthquake risk. One of SCEC's priority objectives is to “develop a geodetic network processing system that will detect anomalous strain transients.” Given the growing number of continuously recording geodetic networks consisting of hundreds of stations, an automated means for systematically searching data for transient signals, especially in near real time, is critical for network operations, hazard monitoring, and event response. The SCEC Transient Detection Test Exercise began in 2008 to foster an active community of researchers working on this problem, explore promising methods, and combine effective approaches in novel ways. A workshop was held in California to assess what has been learned thus far and discuss areas of focus as the project moves forward.

  20. Method of detecting system function by measuring frequency response

    DOEpatents

    Morrison, John L.; Morrison, William H.

    2008-07-01

    Real time battery impedance spectrum is acquired using one time record, Compensated Synchronous Detection (CSD). This parallel method enables battery diagnostics. The excitation current to a test battery is a sum of equal amplitude sin waves of a few frequencies spread over range of interest. The time profile of this signal has duration that is a few periods of the lowest frequency. The voltage response of the battery, average deleted, is the impedance of the battery in the time domain. Since the excitation frequencies are known, synchronous detection processes the time record and each component, both magnitude and phase, is obtained. For compensation, the components, except the one of interest, are reassembled in the time domain. The resulting signal is subtracted from the original signal and the component of interest is synchronously detected. This process is repeated for each component.

  1. Speckle correlation method used to detect an object's surface slope

    SciTech Connect

    Smid, Petr; Horvath, Pavel; Hrabovsky, Miroslav

    2006-09-20

    We present a technique employing a speckle pattern correlation method for detection of the slope of an object's surface. Controlled translation of an object under investigation and numerical correlation of speckle patterns recorded during its motion give information used to evaluate the tilt of the object. The proposed optical setup uses a symmetrical arrangement of detection planes in the image field and enables one to detect the tilt of an object's surface within the interval(10 deg. -30 deg. ). Simulation analysis shows how to control the measuring range. The presented theory, simulation analysis, and setup are verified through an experiment by measurement of the slope of a surface of a cube made out of steel.

  2. Speckle correlation method used to detect an object's surface slope.

    PubMed

    Smíd, Petr; Horváth, Pavel; Hrabovský, Miroslav

    2006-09-20

    We present a technique employing a speckle pattern correlation method for detection of the slope of an object's surface. Controlled translation of an object under investigation and numerical correlation of speckle patterns recorded during its motion give information used to evaluate the tilt of the object. The proposed optical setup uses a symmetrical arrangement of detection planes in the image field and enables one to detect the tilt of an object's surface within the interval (10 degrees-30 degrees). Simulation analysis shows how to control the measuring range. The presented theory, simulation analysis, and setup are verified through an experiment by measurement of the slope of a surface of a cube made out of steel.

  3. PCA method for automated detection of mispronounced words

    NASA Astrophysics Data System (ADS)

    Ge, Zhenhao; Sharma, Sudhendu R.; Smith, Mark J. T.

    2011-06-01

    This paper presents a method for detecting mispronunciations with the aim of improving Computer Assisted Language Learning (CALL) tools used by foreign language learners. The algorithm is based on Principle Component Analysis (PCA). It is hierarchical with each successive step refining the estimate to classify the test word as being either mispronounced or correct. Preprocessing before detection, like normalization and time-scale modification, is implemented to guarantee uniformity of the feature vectors input to the detection system. The performance using various features including spectrograms and Mel-Frequency Cepstral Coefficients (MFCCs) are compared and evaluated. Best results were obtained using MFCCs, achieving up to 99% accuracy in word verification and 93% in native/non-native classification. Compared with Hidden Markov Models (HMMs) which are used pervasively in recognition application, this particular approach is computational efficient and effective when training data is limited.

  4. Heavy metals detection in sediments using PGNAA method.

    PubMed

    Da-Qian, Hei; Wen-Bao, Jia; Zhou, Jiang; Can, Cheng; Jia-Tong, Li; Hong-Tao, Wang

    2016-06-01

    A prompt gamma ray neutron activation analysis detection system was developed to detect the heavy metals in sediments by using an (241)Am-Be neutron source and BGO detector. The samples containing cadmium and mercury were used to test the performance of setup. The linear relationship between prompt gamma ray counts and the concentrations was studied. The results showed the counts of the prompt gamma rays from cadmium do not increase linearly with its concentrations, while the prompt gamma ray counts from Hg vary nearly linearly with the concentrations, due to the neutron self-shielding. Then a method was used to correct the effect and the non-linearly response was restored after the correction. And the minimum detectable concentration of Cd and Hg were 52.8 (at 8.484MeV) and 81.6 (at 5.967MeV) ppm, respectively.

  5. The method for detecting diffusion ring diameter in Hemagglutinin measuring

    NASA Astrophysics Data System (ADS)

    Jing, Wenbo; Liu, Xue; Duan, Jin; Wang, Xiao-man

    2014-11-01

    The diffuser ring diameter measurement is the most critical in hemagglutinin Measuring. The traditional methods, such as a vernier caliper or high-definition scanned images are subjective and low for the measurement data reliability. Propose high-resolution diffusion ring image for drop-resolution processing, adaptive Canny operator and local detection method to extract complete and clear diffusion ring boundaries, and finally make use of polynomial interpolation algorithm to make diffusion ring outer boundary pixel coordinates achieve sub-pixel accuracy and the least-squares fitting circle algorithm to calculate the precise center of the circle and the diameter of the diffuser ring. Experimental results show that the method detection time is only 63.61ms, which is a faster speed; diffuser ring diameter estimation error can achieve 0.55 pixel, high stability in experimental data. This method is adapted to the various types of influenza vaccine hemagglutinin content measurements, and has important value in the influenza vaccine quality detection.

  6. Method for detecting free fiber ends in tissue paper

    NASA Astrophysics Data System (ADS)

    Raunio, Jukka-Pekka; Ritala, Risto

    2013-12-01

    Softness is one of the major properties of tissue paper. Tissue softness can be divided into bulk and surface softness. The bulk softness can be measured quite reliably by measuring the thickness and elasticity of a sheet. However, the measurement of surface softness is not straightforward. One significant factor influencing surface softness is the fibers extending from the surface of the tissue paper. This paper presents a novel imaging method to detect the amount of such fibers on the tissue paper. The method is based on the detection of shadows caused by the free fiber ends. The shadows cannot be detected as such from the reflectance image of the sheet because of the wavy surface of tissue paper. Thus, the 3D information of the surface was estimated based on the photometric stereo, and the intensity variations caused by the wavy surface were filtered out. The method has the advantages over previous methods of improved accuracy and the possibility of implementation in a running paper machine.

  7. An iterative method for airway segmentation using multiscale leakage detection

    NASA Astrophysics Data System (ADS)

    Nadeem, Syed Ahmed; Jin, Dakai; Hoffman, Eric A.; Saha, Punam K.

    2017-02-01

    There are growing applications of quantitative computed tomography for assessment of pulmonary diseases by characterizing lung parenchyma as well as the bronchial tree. Many large multi-center studies incorporating lung imaging as a study component are interested in phenotypes relating airway branching patterns, wall-thickness, and other morphological measures. To our knowledge, there are no fully automated airway tree segmentation methods, free of the need for user review. Even when there are failures in a small fraction of segmentation results, the airway tree masks must be manually reviewed for all results which is laborious considering that several thousands of image data sets are evaluated in large studies. In this paper, we present a CT-based novel airway tree segmentation algorithm using iterative multi-scale leakage detection, freezing, and active seed detection. The method is fully automated requiring no manual inputs or post-segmentation editing. It uses simple intensity based connectivity and a new leakage detection algorithm to iteratively grow an airway tree starting from an initial seed inside the trachea. It begins with a conservative threshold and then, iteratively shifts toward generous values. The method was applied on chest CT scans of ten non-smoking subjects at total lung capacity and ten at functional residual capacity. Airway segmentation results were compared to an expert's manually edited segmentations. Branch level accuracy of the new segmentation method was examined along five standardized segmental airway paths (RB1, RB4, RB10, LB1, LB10) and two generations beyond these branches. The method successfully detected all branches up to two generations beyond these segmental bronchi with no visual leakages.

  8. Outlier Detection with a Hybrid Artificial Intelligence Method

    NASA Astrophysics Data System (ADS)

    Mejía-Lavalle, Manuel; Obregón, Ricardo Gómez; Vivar, Atlántida Sánchez

    We propose a simple and efficient hybrid artificial intelligence method to detect exceptional data. The proposed method includes a novel end-user explanation feature. After various attempts, the best design was based on an unsupervised learning schema, which uses an hybrid adaptation of the Artificial Neural Network paradigms, the Case Based Reasoning methodology, the Data Mining area, and the Expert System shells. In our method, the cluster that contains the smaller number of instances is considered as outlier data. The method provides an explanation to the end user about why this cluster is exceptional regarding to the data universe. The proposed method has been tested and compared successfully not only with well-known academic data, but also with a real and very large financial database that contains attributes with numerical and categorical values.

  9. An electromagnetic induction method for underground target detection and characterization

    SciTech Connect

    Bartel, L.C.; Cress, D.H.

    1997-01-01

    An improved capability for subsurface structure detection is needed to support military and nonproliferation requirements for inspection and for surveillance of activities of threatening nations. As part of the DOE/NN-20 program to apply geophysical methods to detect and characterize underground facilities, Sandia National Laboratories (SNL) initiated an electromagnetic induction (EMI) project to evaluate low frequency electromagnetic (EM) techniques for subsurface structure detection. Low frequency, in this case, extended from kilohertz to hundreds of kilohertz. An EMI survey procedure had already been developed for borehole imaging of coal seams and had successfully been applied in a surface mode to detect a drug smuggling tunnel. The SNL project has focused on building upon the success of that procedure and applying it to surface and low altitude airborne platforms. Part of SNL`s work has focused on improving that technology through improved hardware and data processing. The improved hardware development has been performed utilizing Laboratory Directed Research and Development (LDRD) funding. In addition, SNL`s effort focused on: (1) improvements in modeling of the basic geophysics of the illuminating electromagnetic field and its coupling to the underground target (partially funded using LDRD funds) and (2) development of techniques for phase-based and multi-frequency processing and spatial processing to support subsurface target detection and characterization. The products of this project are: (1) an evaluation of an improved EM gradiometer, (2) an improved gradiometer concept for possible future development, (3) an improved modeling capability, (4) demonstration of an EM wave migration method for target recognition, and a demonstration that the technology is capable of detecting targets to depths exceeding 25 meters.

  10. A rapid DNA extraction method suitable for human papillomavirus detection.

    PubMed

    Brestovac, Brian; Wong, Michelle E; Costantino, Paul S; Groth, David

    2014-04-01

    Infection with oncogenic human papillomavirus (HPV) genotypes is necessary for the development of cervical cancer. Testing for HPV DNA from liquid based cervical samples can be used as an adjunct to traditional cytological screening. In addition there are ongoing viral load, genotyping, and prevalence studies. Therefore, a sensitive DNA extraction method is needed to maximize the efficiency of HPV DNA detection. The XytXtract Tissue kit is a DNA extraction kit that is rapid and so could be useful for HPV testing, particularly in screening protocols. This study was undertaken to determine the suitability of this method for HPV detection. DNA extraction from HeLa and Caski cell lines containing HPV 18 and 16 respectively together with DNA from five liquid based cervical samples were used in a HPV PCR assay. DNA was also extracted using the QIAamp DNA mini kit (Qiagen, Hilden, Germany) as a comparison. DNA extracts were serially diluted and assayed. HPV DNA was successfully detected in cell lines and cervical samples using the XytXtract Tissue kit. In addition, the XytXtract method was found to be more sensitive than the QIAmp method as determined by a dilution series of the extracted DNA. While the XytXtract method is a closed, the QIAamp method uses a spin column with possible loss of DNA through DNA binding competition of the matrix, which could impact on the final extraction efficiency. The XytXtract is a cheap, rapid and efficient method for extracting HPV DNA from both cell lines and liquid based cervical samples.

  11. Minimum detectable gas concentration performance evaluation method for gas leak infrared imaging detection systems.

    PubMed

    Zhang, Xu; Jin, Weiqi; Li, Jiakun; Wang, Xia; Li, Shuo

    2017-04-01

    Thermal imaging technology is an effective means of detecting hazardous gas leaks. Much attention has been paid to evaluation of the performance of gas leak infrared imaging detection systems due to several potential applications. The minimum resolvable temperature difference (MRTD) and the minimum detectable temperature difference (MDTD) are commonly used as the main indicators of thermal imaging system performance. This paper establishes a minimum detectable gas concentration (MDGC) performance evaluation model based on the definition and derivation of MDTD. We proposed the direct calculation and equivalent calculation method of MDGC based on the MDTD measurement system. We build an experimental MDGC measurement system, which indicates the MDGC model can describe the detection performance of a thermal imaging system to typical gases. The direct calculation, equivalent calculation, and direct measurement results are consistent. The MDGC and the minimum resolvable gas concentration (MRGC) model can effectively describe the performance of "detection" and "spatial detail resolution" of thermal imaging systems to gas leak, respectively, and constitute the main performance indicators of gas leak detection systems.

  12. Sensitivity of Edge Detection Methods for Quantifying Cell Migration Assays

    PubMed Central

    Treloar, Katrina K.; Simpson, Matthew J.

    2013-01-01

    Quantitative imaging methods to analyze cell migration assays are not standardized. Here we present a suite of two-dimensional barrier assays describing the collective spreading of an initially-confined population of 3T3 fibroblast cells. To quantify the motility rate we apply two different automatic image detection methods to locate the position of the leading edge of the spreading population after , and hours. These results are compared with a manual edge detection method where we systematically vary the detection threshold. Our results indicate that the observed spreading rates are very sensitive to the choice of image analysis tools and we show that a standard measure of cell migration can vary by as much as 25% for the same experimental images depending on the details of the image analysis tools. Our results imply that it is very difficult, if not impossible, to meaningfully compare previously published measures of cell migration since previous results have been obtained using different image analysis techniques and the details of these techniques are not always reported. Using a mathematical model, we provide a physical interpretation of our edge detection results. The physical interpretation is important since edge detection algorithms alone do not specify any physical measure, or physical definition, of the leading edge of the spreading population. Our modeling indicates that variations in the image threshold parameter correspond to a consistent variation in the local cell density. This means that varying the threshold parameter is equivalent to varying the location of the leading edge in the range of approximately 1–5% of the maximum cell density. PMID:23826283

  13. Sensitivity of edge detection methods for quantifying cell migration assays.

    PubMed

    Treloar, Katrina K; Simpson, Matthew J

    2013-01-01

    Quantitative imaging methods to analyze cell migration assays are not standardized. Here we present a suite of two-dimensional barrier assays describing the collective spreading of an initially-confined population of 3T3 fibroblast cells. To quantify the motility rate we apply two different automatic image detection methods to locate the position of the leading edge of the spreading population after 24, 48 and 72 hours. These results are compared with a manual edge detection method where we systematically vary the detection threshold. Our results indicate that the observed spreading rates are very sensitive to the choice of image analysis tools and we show that a standard measure of cell migration can vary by as much as 25% for the same experimental images depending on the details of the image analysis tools. Our results imply that it is very difficult, if not impossible, to meaningfully compare previously published measures of cell migration since previous results have been obtained using different image analysis techniques and the details of these techniques are not always reported. Using a mathematical model, we provide a physical interpretation of our edge detection results. The physical interpretation is important since edge detection algorithms alone do not specify any physical measure, or physical definition, of the leading edge of the spreading population. Our modeling indicates that variations in the image threshold parameter correspond to a consistent variation in the local cell density. This means that varying the threshold parameter is equivalent to varying the location of the leading edge in the range of approximately 1-5% of the maximum cell density.

  14. Renal Hypoxia in CKD; Pathophysiology and Detecting Methods

    PubMed Central

    Hirakawa, Yosuke; Tanaka, Tetsuhiro; Nangaku, Masaomi

    2017-01-01

    Chronic kidney disease (CKD) is a major public health problem. Accumulating evidence suggests that CKD aggravates renal hypoxia, and in turn, renal hypoxia accelerates CKD progression. To eliminate this vicious cycle, hypoxia-related therapies, such as hypoxia-inducible factor (HIF) activation (prolyl hydroxylase domain inhibition) or NF-E2-related factor 2 activation, are currently under investigation. Clinical studies have revealed heterogeneity in renal oxygenation; therefore, the detection of patients with more hypoxic kidneys can be used to identify likely responders to hypoxia-oriented therapies. In this review, we provide a detailed description of current hypoxia detection methods. HIF degradation correlates with the intracellular oxygen concentration; thus, methods that can detect intracellular oxygen tension changes are desirable. The use of a microelectrode is a classical technique that is superior in quantitative performance; however, its high invasiveness and the fact that it reflects the extracellular oxygen tension are disadvantages. Pimonidazole protein adduct immunohistochemistry and HIF activation detection reflect intracellular oxygen tension, but these techniques yield qualitative data. Blood oxygen level-dependent magnetic resonance imaging has the advantage of low invasiveness, high quantitative performance, and application in clinical use, but its biggest disadvantage is that it measures only deoxyhemoglobin concentrations. Phosphorescence lifetime measurement is a relatively novel in vivo oxygen sensing technique that has the advantage of being quantitative; however, it has several disadvantages, such as toxicity of the phosphorescent dye and the inability to assess deeper tissues. Understanding the advantages and disadvantages of these hypoxia detection methods will help researchers precisely assess renal hypoxia and develop new therapeutics against renal hypoxia-associated CKD. PMID:28270773

  15. Detecting sincerity of effort: a summary of methods and approaches.

    PubMed

    Lechner, D E; Bradbury, S F; Bradley, L A

    1998-08-01

    Despite the widespread use of methods that are supposed to detect the sincerity of patients' efforts in clinical assessment, little has been written summarizing the literature that addresses the reliability and validity of measurements obtained with these methods. The purpose of this article is to review the literature on the reliability and validity of scores for Waddell's nonorganic signs, descriptions of pain behavior and symptom magnification, coefficients of variation, correlations between musculoskeletal evaluation and function, grip measurements, and the relationship between heart rate and pain intensity. The authors of the articles reviewed conclude that none of these methods have been examined adequately. Some of these methods, such as Waddell's nonorganic signs, were not developed for the purpose of detecting sincerity of effort. Clinicians are encouraged to critically read the literature addressing these methods. With further research, some of the discussed methods may prove useful. Until such research is reported in the peer-reviewed literature, however, clinicians should avoid basing evaluation of sincerity of effort on these tests. Therapists are encouraged, instead, to use a biobehavioral approach to better understand and address the complex factors underlying delayed recovery.

  16. Rapid detection of malaria parasite by toluidine blue method: a new staining method.

    PubMed

    Annam, Vamseedhar; Mohan, Chakkirala Nalini; Mrinalini, Vazhayil Ramunny

    2013-10-01

    Malaria is a commonest mosquito-borne infectious disease worldwide. Early identification and management of malaria prevents complications and mortality. Identification of the malaria mainly relies on detection of the parasite on blood smears. The present study was conducted to compare Toluidine blue method with Leishman method for detection of malaria parasite and also to study the efficacy and advantages of using Toluidine blue method. In 540 consecutive patients with clinical suspicion of malaria, peripheral smears were prepared. Smears were processed for both conventional Leishman method and Toluidine blue method simultaneously. The significance of Toluidine blue method over Leishman method was analyzed using Chi-square (χ(2)) test. Out of 540 smears, 28.3% (153/540) were positive for malaria parasite on conventional Leishman method, while the smear positivity was more by Toluidine blue method to 33.3% (180/540) [P value < 0.01]. The remaining 66.67% (360/540) were negative by both Toluidine blue method and conventional Leishman method. The Toluidine blue method is simple, rapid, inexpensive, and easily available. The implementation of Toluidine blue method clearly improves microscopic detection of malaria parasite and can be a useful contribution to routine hematology even at rural health sectors.

  17. An improved unsupervised clustering-based intrusion detection method

    NASA Astrophysics Data System (ADS)

    Hai, Yong J.; Wu, Yu; Wang, Guo Y.

    2005-03-01

    Practical Intrusion Detection Systems (IDSs) based on data mining are facing two key problems, discovering intrusion knowledge from real-time network data, and automatically updating them when new intrusions appear. Most data mining algorithms work on labeled data. In order to set up basic data set for mining, huge volumes of network data need to be collected and labeled manually. In fact, it is rather difficult and impractical to label intrusions, which has been a big restrict for current IDSs and has led to limited ability of identifying all kinds of intrusion types. An improved unsupervised clustering-based intrusion model working on unlabeled training data is introduced. In this model, center of a cluster is defined and used as substitution of this cluster. Then all cluster centers are adopted to detect intrusions. Testing on data sets of KDDCUP"99, experimental results demonstrate that our method has good performance in detection rate. Furthermore, the incremental-learning method is adopted to detect those unknown-type intrusions and it decreases false positive rate.

  18. Circulating tumor cell detection using photoacoustic spectral methods

    NASA Astrophysics Data System (ADS)

    Strohm, Eric M.; Berndl, Elizabeth S. L.; Kolios, Michael C.

    2014-03-01

    A method to detect and differentiate circulating melanoma tumor cells (CTCs) from blood cells using ultrasound and photoacoustic signals with frequencies over 100 MHz is presented. At these frequencies, the acoustic wavelength is similar to the dimensions of a cell, which results in unique features in the signal; periodically varying minima and maxima occur throughout the power spectrum. The spacing between minima depends on the ratio of the size to sound speed of the cell. Using a 532 nm pulsed laser and a 375 MHz center frequency wide-bandwidth transducer, the ultrasound and photoacoustic signals were measured from single cells. A total of 80 cells were measured, 20 melanoma cells, 20 white blood cells (WBCs) and 40 red blood cells (RBCs). The photoacoustic spectral spacing Δf between minima was 95 +/- 15 MHz for melanoma cells and greater than 230 MHz for RBCs. No photoacoustic signal was detected from WBCs. The ultrasonic spectral spacing between minima was 46 +/- 9 MHz for melanoma cells and 98 +/- 11 for WBCs. Both photoacoustic and ultrasound signals were detected from melanoma cells, while only ultrasound signals were detected from WBCs. RBCs showed distinct photoacoustic spectral variations in comparison to any other type of cell. Using the spectral spacing and signal amplitudes, each cell type could be grouped together to aid in cell identification. This method could be used for label-free counting and classifying cells in a sample.

  19. Modified Reaction Detection Methods on the Drop Weight Impact Machine

    NASA Astrophysics Data System (ADS)

    Preston, Daniel; Brown, Geoffrey; Koby, Joseph

    2013-06-01

    High explosives small-scale sensitivity testing has been a hallmark of safety screening since WWII. Sensitivity testing was once as crude as using the end of a broom stick to scrape explosives on the floor, looking, listening, and smelling for signs of reaction. Since then, a wide variety of testing apparatus have been developed to explore the effects of different stimuli on explosives. In concert with the development of the machines themselves the reaction detection methods have also evolved. Some modern detection devices include sound level meters, high speed cameras, and light detection sensors to name a few. For this paper, the viability of new and modified reaction detection methods employed on the LANL Explosives Research Laboratory (ERL) Type 12 Drop Weight Impact Machine is explored. A large bandwidth microphone and a series of strain gauges were installed on the machine and, with an oscilloscope, were able to capture the acoustic and mechanical wave forms during an impact event. These data were then used as a metric for developing reaction criteria for explosives on drop weight impact.

  20. A review of damage detection methods for wind turbine blades

    NASA Astrophysics Data System (ADS)

    Li, Dongsheng; Ho, Siu-Chun M.; Song, Gangbing; Ren, Liang; Li, Hongnan

    2015-03-01

    Wind energy is one of the most important renewable energy sources and many countries are predicted to increase wind energy portion of their whole national energy supply to about twenty percent in the next decade. One potential obstacle in the use of wind turbines to harvest wind energy is the maintenance of the wind turbine blades. The blades are a crucial and costly part of a wind turbine and over their service life can suffer from factors such as material degradation and fatigue, which can limit their effectiveness and safety. Thus, the ability to detect damage in wind turbine blades is of great significance for planning maintenance and continued operation of the wind turbine. This paper presents a review of recent research and development in the field of damage detection for wind turbine blades. Specifically, this paper reviews frequently employed sensors including fiber optic and piezoelectric sensors, and four promising damage detection methods, namely, transmittance function, wave propagation, impedance and vibration based methods. As a note towards the future development trend for wind turbine sensing systems, the necessity for wireless sensing and energy harvesting is briefly presented. Finally, existing problems and promising research efforts for online damage detection of turbine blades are discussed.

  1. Alcohol Detection in Exhaled Air by NDIR Method

    NASA Astrophysics Data System (ADS)

    Fujitsuka, Norio; Yonemura, Masatoshi; Sakakibara, Kiyomi; Taguchi, Toshiyuki; Wakita, Toshihiro

    In recent years, the increase in traffic accidents associated with drunk driving has become a serious social issue. Therefore, there is a need for an in-vehicle system that can detect the fact that the driver is under the influence of alcohol. We thought a method for alcohol detection in the breath of the driver, based on a nondispersive infrared (NDIR) method, is suitable for this system. Since alcohol content in the driver's breath is significantly diluted at the sensor device, it is necessary that the sensor is highly sensitive to detect diluted alcohol. A quantum cascade laser was used to produce highly intense infrared light source. An infrared hollow fiber used in medical treatment was utilized as a gas absorption cell. Since the core of the fiber is hollow, gas is introduced for analyzer. The flexibility of the fiber allowed it to be looped so that 2 m fiber in length could be formed into a compact coil of 29 cm in diameter. It was clarified that the light intensity change of light output from the hollow fiber with ethanol density, and rarefied ethanol as small as 1 ppm in density was detected.

  2. Novel separation and detection methods of DNA fragments in electrophoresis

    SciTech Connect

    Chan, K.C.

    1992-01-01

    A charge-coupled device (CCD) based electrophoresis system was developed. The system allowed non-destructive, sensitive, and on-line detection of native DNA in slab-gel electrophoresis via ultraviolet absorption measurement. The detection limit of double-stranded DNA fragment was 5 ng per band. Since the amount of DNA used in this experiment was typical, the CCD-based system could be readily implemented in molecular biology. Gel-filled and non-gel sieving capillary electrophoresis (CE) was developed for rapid and efficient separation of double-stranded DNA fragments. For the gel-filled CE separation a new gel matrix, the HydroLink gel (HL), was used. The HL capillary gel was easier to cast than the polyacrylamide capillary gel. For the non-gel separation, a GC capillary was used as the separation chamber, and cellulose additive was included in the electrophoresis as the sieving medium. Indirect fluorometry was applied in non-gel and gel electrophoresis for the detection of DNA fragments. This method allowed nondestructive and on-line detection of DNA during electrophoresis. The amount of DNA used with this method was comparable to those obtained with absorption measurement.

  3. Novel separation and detection methods of DNA fragments in electrophoresis

    SciTech Connect

    Chan, King Cheung.

    1993-01-27

    A charge-coupled device (CCD) based electrophoresis system was developed. The system allowed non-destructive, sensitive, and on-line detection of native DNA in slab-gel electrophoresis via ultraviolet absorption measurement. The detection limit of double-stranded DNA fragment was 5 ng per band. Since the amount of DNA used in this experiment was typical, the CCD-based system could be readily implemented in molecular biology. Gel-filled and non-gel sieving capillary electrophoresis was developed for rapid and efficient separation of double-stranded DNA fragments. For the gel-filled CE separation a new gel matrix, the HydroLink gel (HL), was used. The HL capillary gel was easier to cast than the polyacrylamide capillary gel. For the non-gel separation, a GC capillary was used as the separation chamber, and cellulose additive was included in the electrophoresis as the sieving medium. Indirect fluorometry was applied in non-gel and gel electrophoresis for the detection of DNA fragments. This method allowed non-destructive and on-line detection of DNA during electrophoresis. The amount of DNA used with this method was comparable to those obtained with absorption measurement.

  4. Fast detection of air contaminants using immunobiological methods

    NASA Astrophysics Data System (ADS)

    Schmitt, Katrin; Bolwien, Carsten; Sulz, Gerd; Koch, Wolfgang; Dunkhorst, Wilhelm; Lödding, Hubert; Schwarz, Katharina; Holländer, Andreas; Klockenbring, Torsten; Barth, Stefan; Seidel, Björn; Hofbauer, Wolfgang; Rennebarth, Torsten; Renzl, Anna

    2009-05-01

    The fast and direct identification of possibly pathogenic microorganisms in air is gaining increasing interest due to their threat for public health, e.g. in clinical environments or in clean rooms of food or pharmaceutical industries. We present a new detection method allowing the direct recognition of relevant germs or bacteria via fluorescence-labeled antibodies within less than one hour. In detail, an air-sampling unit passes particles in the relevant size range to a substrate which contains antibodies with fluorescence labels for the detection of a specific microorganism. After the removal of the excess antibodies the optical detection unit comprising reflected-light and epifluorescence microscopy can identify the microorganisms by fast image processing on a single-particle level. First measurements with the system to identify various test particles as well as interfering influences have been performed, in particular with respect to autofluorescence of dust particles. Specific antibodies for the detection of Aspergillus fumigatus spores have been established. The biological test system consists of protein A-coated polymer particles which are detected by a fluorescence-labeled IgG. Furthermore the influence of interfering particles such as dust or debris is discussed.

  5. Means and method of detection in chemical separation procedures

    DOEpatents

    Yeung, E.S.; Koutny, L.B.; Hogan, B.L.; Cheung, C.K.; Yinfa Ma.

    1993-03-09

    A means and method are described for indirect detection of constituent components of a mixture separated in a chemical separation process. Fluorescing ions are distributed across the area in which separation of the mixture will occur to provide a generally uniform background fluorescence intensity. For example, the mixture is comprised of one or more charged analytes which displace fluorescing ions where its constituent components separate to. Fluorescing ions of the same charge as the charged analyte components cause a displacement. The displacement results in the location of the separated components having a reduced fluorescence intensity to the remainder of the background. Detection of the lower fluorescence intensity areas can be visually, by photographic means and methods, or by automated laser scanning.

  6. Means and method of detection in chemical separation procedures

    DOEpatents

    Yeung, Edward S.; Koutny, Lance B.; Hogan, Barry L.; Cheung, Chan K.; Ma, Yinfa

    1993-03-09

    A means and method for indirect detection of constituent components of a mixture separated in a chemical separation process. Fluorescing ions are distributed across the area in which separation of the mixture will occur to provide a generally uniform background fluorescence intensity. For example, the mixture is comprised of one or more charged analytes which displace fluorescing ions where its constituent components separate to. Fluorescing ions of the same charge as the charged analyte components cause a displacement. The displacement results in the location of the separated components having a reduced fluorescence intensity to the remainder of the background. Detection of the lower fluorescence intensity areas can be visually, by photographic means and methods, or by automated laser scanning.

  7. Native Fluorescence Detection Methods, Devices, and Systems for Organic Compounds

    NASA Technical Reports Server (NTRS)

    Hug, William F. (Inventor); Bhartia, Rohit (Inventor); Reid, Ray D. (Inventor); Lane, Arthur L. (Inventor)

    2016-01-01

    Naphthalene, benzene, toluene, xylene, and other volatile organic compounds VOCs have been identified as serious health hazards. Embodiments of the invention are directed to methods and apparatus for near-real-time in-situ detection and accumulated dose measurement of exposure to naphthalene vapor and other hazardous gaseous VOCs. The methods and apparatus employ excitation of fluorophors native or endogenous to compounds of interest using light sources emitting in the ultraviolet below 300 nm and measurement of native fluorescence emissions in distinct wavebands above the excitation wavelength. The apparatus of some embodiments are cell-phone-sized sensor/dosimeter "badges" to be worn by personnel potentially exposed to hazardous VOCs. The badge sensor of some embodiments provides both real time detection and data logging of exposure to naphthalene or other VOCs of interest from which both instantaneous and accumulated dose can be determined.

  8. Devices and methods to detect and quantify trace gases

    DOEpatents

    Allendorf, Mark D.; Robinson, Alex

    2016-05-03

    Sensing devices based on a surface acoustic wave ("SAW") device coated with an absorbent crystalline or amorphous layer for detecting at least one chemical analyte in a gaseous carrier. Methods for detecting the presence of a chemical analyte in a gaseous carrier using such devices are also disclosed. The sensing devices and methods for their use may be configured for sensing chemical analytes selected from the group consisting of water vapor, carbon dioxide, methanol, ethanol, carbon monoxide, nitric oxide, nitrous oxide, organic amines, organic compounds containing NO.sub.2 groups, halogenated hydrocarbons, acetone, hexane, toluene, isopropanol, alcohols, alkanes, alkenes, benzene, functionalized aromatics, ammonia (NH.sub.3), phosgene (COCl.sub.2), sulfur mustard, nerve agents, sulfur dioxide, tetrahydrofuran (THF) and methyltertbutyl ether (MTBE) and combinations thereof.

  9. Drop weight impact measurements of HE sensitivity: modified detection methods

    NASA Astrophysics Data System (ADS)

    Preston, D. N.; Brown, G. W.; Tappan, B. C.; Oshwald, D. M.; Koby, J. R.; Schoonover, M. L.

    2014-05-01

    High explosives small-scale sensitivity testing has been a hallmark of safety screening since WWII. Sensitivity testing was once crude and simple; broom sticks were used to scrape explosives on the floor while experimenters would look, listen, and smell for signs of a reaction. Since then, a wide variety of testing apparatus have been developed to explore the effects of different stimuli on explosives. In concert with the development of the machines themselves, the reaction detection methods have also evolved. This paper's focus is on the Los Alamos National Laboratory's (LANL) drop weight impact machine and reaction detection methods. A critical evaluation of results is presented with cautionary examples of false positives that can occur with non-explosive materials.

  10. Glacial Till Detection Experiments With Transient Electromagnetic Methods

    NASA Astrophysics Data System (ADS)

    Bucki, A. K.; Adema, G.

    2003-12-01

    Transient Electromagnetic (TEM) investigations have been carried out on Fireweed Rock Glacier in Wrangell-St. Elias National Park, Alaska and the East Fork Toklat Glacier in Denali National Park, Alaska. TEM methods were effective in determining the geometry of the rock glacier but were more limited in resolution on the ice glacier. A conductive layer beneath the rock glacier was identified, and its distribution is consistent with a till-like layer. A similar layer was not detected beneath the glacier; the lack of this conductive layer limits the resolution of glacial depth. These experiments and forward modeling indicate that TEM methods may provide a means for detecting a sufficiently thick and conductive till layer beneath glaciers and rock glaciers.

  11. Seizure detection by a novel wavelet packet method.

    PubMed

    Tafreshi, Reza; Dumont, Guy; Gross, Donald; Ries, Craig R; Puil, Ernie; MacLeod, Bern A

    2006-01-01

    We describe a novel wavelet-based method for the detection of seizure in patients with temporal lobe epilepsy. This method uses local discriminant bases and cross- data entropy algorithms to identify nodes of a wavelet packet dictionary that best discriminate preictal from ictal EEG signals. The algorithms are based on relative entropy criterion as a measure of discrepancy between different classes of signals. The frequency bands associated with these nodes were in the range of interest for seizure events. After selecting two bands, we determined the ratio of energies at the level of wavelet packet chosen by the cross-data entropy algorithm. Preliminary results demonstrate that the wavelet packet energy ratio could serve as a robust criterion in seizure detection.

  12. A multivariate based event detection method and performance comparison with two baseline methods.

    PubMed

    Liu, Shuming; Smith, Kate; Che, Han

    2015-09-01

    Early warning systems have been widely deployed to protect water systems from accidental and intentional contamination events. Conventional detection algorithms are often criticized for having high false positive rates and low true positive rates. This mainly stems from the inability of these methods to determine whether variation in sensor measurements is caused by equipment noise or the presence of contamination. This paper presents a new detection method that identifies the existence of contamination by comparing Euclidean distances of correlation indicators, which are derived from the correlation coefficients of multiple water quality sensors. The performance of the proposed method was evaluated using data from a contaminant injection experiment and compared with two baseline detection methods. The results show that the proposed method can differentiate between fluctuations caused by equipment noise and those due to the presence of contamination. It yielded higher possibility of detection and a lower false alarm rate than the two baseline methods. With optimized parameter values, the proposed method can correctly detect 95% of all contamination events with a 2% false alarm rate.

  13. Improved Collision-Detection Method for Robotic Manipulator

    NASA Technical Reports Server (NTRS)

    Leger, Chris

    2003-01-01

    An improved method has been devised for the computational prediction of a collision between (1) a robotic manipulator and (2) another part of the robot or an external object in the vicinity of the robot. The method is intended to be used to test commanded manipulator trajectories in advance so that execution of the commands can be stopped before damage is done. The method involves utilization of both (1) mathematical models of the robot and its environment constructed manually prior to operation and (2) similar models constructed automatically from sensory data acquired during operation. The representation of objects in this method is simpler and more efficient (with respect to both computation time and computer memory), relative to the representations used in most prior methods. The present method was developed especially for use on a robotic land vehicle (rover) equipped with a manipulator arm and a vision system that includes stereoscopic electronic cameras. In this method, objects are represented and collisions detected by use of a previously developed technique known in the art as the method of oriented bounding boxes (OBBs). As the name of this technique indicates, an object is represented approximately, for computational purposes, by a box that encloses its outer boundary. Because many parts of a robotic manipulator are cylindrical, the OBB method has been extended in this method to enable the approximate representation of cylindrical parts by use of octagonal or other multiple-OBB assemblies denoted oriented bounding prisms (OBPs), as in the example of Figure 1. Unlike prior methods, the OBB/OBP method does not require any divisions or transcendental functions; this feature leads to greater robustness and numerical accuracy. The OBB/OBP method was selected for incorporation into the present method because it offers the best compromise between accuracy on the one hand and computational efficiency (and thus computational speed) on the other hand.

  14. Mobile Detection of Fugitive Emissions using Computationally Optimized Geochemical Methods

    NASA Astrophysics Data System (ADS)

    Marshall, A. D.; Risk, D. A.; Lavoie, M.; Brooks, B. G.; Macintyre, C. M.; Baillie, J.; Laybolt, W. D.; Williams, J. P.; Goeckede, M.; Phillips, C. L.

    2015-12-01

    The grand challenge of surface leak monitoring is to detect and attribute even small leaks across large energy development sites, which often span hundreds of square kilometres. Ratio-based geochemical methods show great potential for near-surface leak detection and attribution in vehicle-based mobile surveys. Ratios are useful especially when applied to concentration anomalies that exceed the Ambient Background (ABG), because they preserve the ratio of emission, and allow for more definitive attribution. Predicting ABG is, however, difficult because its variance originates from many processes including atmospheric patterns, local vegetation, other natural factors, and human activity. Here we present a method of vehicle-based atmospheric leak detection. We have developed a signal conditioning process for accommodating a variable ABG throughout a survey dataset. ABG is the lowest value of a species within a time interval of variable length, and anomalies are detected when ratios of excess concentration (above ABG) exceed defined ratio limits based on expected sources. We computationally iterate through many configurations of ABG time interval and other parameters to find an optimized scenario. In surveys of CH4, δ13CH4, CO2 and H2S at a large energy development with active infrastructure, we compared our technique to a concentration threshold detection technique (2 ppm CH4), and a variation of our process where ABG is assumed to be the lowest dataset value. Across ~1500 km of survey data, our process detected 8 times more leak anomalies than did the threshold technique. The lowest value background technique detected a similar number of leak anomalies as the optimized ABG, but was oversensitive to combustion (CO2-rich) emissions. With the optimized scenarios we observed some persistent leak anomalies in as many as 50% of survey passes, throughout different seasons and wind conditions. Leak persistence showed no significant relationship to leak size. CO2-rich leaks

  15. New qualitative detection methods of genetically modified potatoes.

    PubMed

    Watanabe, Takahiro; Kuribara, Hideo; Mishima, Takashi; Kikuchi, Hiroyuki; Kodama, Takashi; Futo, Satoshi; Kasama, Kikuko; Toyota, Akie; Nouno, Masanori; Saita, Ayako; Takahashi, Kunihiko; Hino, Akihiro; Akiyama, Hiroshi; Maitani, Tamio; Kubo, Misao

    2004-09-01

    In Japan, 8 lines of genetically modified (GM) potato (2 lines of NewLeaf potato; NL, 3 lines of NewLeaf Plus potato; NLP, and 3 lines of NewLeaf Y potato; NLY) have already been authorized as safe for use in foods and feeds. We have developed polymerase chain reaction (PCR) methods for the qualitative detection of the GM potatoes for the screening and the identification of NL, NLP and NLY. The gene encoding uridine diphosphate (UDP)-glucose pyrophosphorylase (UGPase) was used as a taxon specific gene. We designed the primer pair to detect the cryIIIA genes as a screening method for GM potatoes because the gene should be inserted in all 8 lines of the GM potatoes. For identification of NL, NLP and NLY, we further designed three specific primer pairs for the different recombinant DNAs (r-DNA) specifically introduced into NL, NLP, or NLY. In addition, to identify the 3 lines of NLY that have been introduced with the same r-DNA, the three line-specific primer pairs for the border sequence between the r-DNA and genomic DNA of NLY 3 lines were designed. Six lines of GM potato used as the test material were specifically identified using the each primer pair under the same PCR condition. The detection limits of all the GM potatoes should be approximately 0.1%. Furthermore, the specificity and reproducibility of the methods were confirmed in a six-laboratory collaborative study.

  16. A review of methods for detect human Papillomavirus infection

    PubMed Central

    2012-01-01

    Human Papillomavirus (HPV) is the most common sexually transmitted virus. Worldwide, the most common high-risk (HR)-HPV are -16/18, and approximately 70% of cervical cancers (CC) are due to infection by these genotypes. Persistent infection by HR-HPV is a necessary but not sufficient cause of this cancer, which develops over a long period through precursor lesions, which can be detected by cytological screening. Although this screening has decreased the incidence of CC, HPV-related cervical disease, including premalignant and malignant lesions, continues to be a major burden on health-care systems. Although not completely elucidated, the HPV-driven molecular mechanisms underlying the development of cervical lesions have provided a number of potential biomarkers for both diagnostic and prognostic use in the clinical management of women with HPV-related cervical disease, and these biomarkers can also be used to increase the positive predictive value of current screening methods. In addition, they can provide insights into the biology of HPV-induced cancer and thus lead to the development of nonsurgical therapies. Considering the importance of detecting HPV and related biomarkers, a variety of methods are being developed for these purposes. This review summarizes current knowledge of detection methods for HPV, and related biomarkers that can be used to discriminate lesions with a high risk of progression to CC. PMID:23131123

  17. Detection of Extraterrestrial Life. Method II- Optical Rotatory Dispersion

    NASA Technical Reports Server (NTRS)

    1963-01-01

    The object of this study is to develop polarimetric methods to detect the presence of DNA (deoxyribonucleic acid) or its congeners in soil suspensions, and through these methods determine the existence of life (as known terrestrially) on other planets. The cotton region associated with optically active organic compounds is being used to detect and characterize the compounds above. An apparatus has been designed and assembled which can measure optical rotations in systems which strongly attenuate incident-polarized, monochromatic light. This instrument was used to measure the optical rotatory dispersion spectra of nucleosides, a polynucleotide, and proteins whose optical density at 260 microns approached 1.0. This work is discussed in the final report on Contract NASR-85, Detection of Extraterrestrial Life, Method II: Optical Rotatory Dispersion. Recent work in Melpar laboratories has reaffirmed these rotatory dispersion spectra. Based upon the analysis of the optical components associated with this apparatus, however, these measurements must be considered as qualitative rather than quantitative. The reason for this is discussed in greater detail subsequently in this report. In addition, an evaluation of the theoretical and instrumental aspects of making rotatory-dispersion measurements in the cotton region has resulted in a procedure for measuring optical rotation.

  18. The use of biochemical methods in extraterrestrial life detection

    NASA Astrophysics Data System (ADS)

    McDonald, Gene

    2006-08-01

    Instrument development for in situ extraterrestrial life detection focuses primarily on the ability to distinguish between biological and non-biological material, mostly through chemical analysis for potential biosignatures (e.g., biogenic minerals, enantiomeric excesses). In constrast, biochemical analysis techniques commonly applied to Earth life focus primarily on the exploration of cellular and molecular processes, not on the classification of a given system as biological or non-biological. This focus has developed because of the relatively large functional gap between life and non-life on Earth today. Life on Earth is very diverse from an environmental and physiological point of view, but is highly conserved from a molecular point of view. Biochemical analysis techniques take advantage of this similarity of all terrestrial life at the molecular level, particularly through the use of biologically-derived reagents (e.g., DNA polymerases, antibodies), to enable analytical methods with enormous sensitivity and selectivity. These capabilities encourage consideration of such reagents and methods for use in extraterrestrial life detection instruments. The utility of this approach depends in large part on the (unknown at this time) degree of molecular compositional differences between extraterrestrial and terrestrial life. The greater these differences, the less useful laboratory biochemical techniques will be without significant modification. Biochemistry and molecular biology methods may need to be "de-focused" in order to produce instruments capable of unambiguously detecting a sufficiently wide range of extraterrestrial biochemical systems. Modern biotechnology tools may make that possible in some cases.

  19. A novel method for upper tropospheric jet stream detection

    NASA Astrophysics Data System (ADS)

    Spengler, Thomas; Spensberger, Clemens

    2014-05-01

    There are several methods to detect upper tropospheric jet streams. These schemes are often based on a threshold-criterion for the wind speed, while others utilise gradients in vorticity or the refractive index for Rossby waves. Most of these schemes diagnose an area or volume, which is identified as the jet stream. For some applications, however, it is of higher value to identify the actual axis of the jet stream. For example, cyclonic and anticyclonic Rossby wave breaking occurs preferentially on the cyclonically and anticyclonically sheared side of the jet stream, respectively, where the jet axis marks the transition between the two types of shear. Furthermore, the definition of an axis allows for the analysis of relative distance between collocated jet streams, allowing for an assessment of potential interaction. We propose a new method to detect jet axes based on deformation and the relative angle of the axis of dilatation. The detection performs equally well for instantaneous data as well as for monthly or even longer time averages of the wind field. We present climatologies of jet axis positions and pinpoint new insights revealed by our method. Furthermore, we present composites for different phases of common climate indices such as the NAO and PNA. We also present jet axis composites for different phases of the MJO supporting earlier findings and highlighting the interaction of the MJO with the Pacific jet stream.

  20. Small RNA Detection by in Situ Hybridization Methods

    PubMed Central

    Urbanek, Martyna O.; Nawrocka, Anna U.; Krzyzosiak, Wlodzimierz J.

    2015-01-01

    Small noncoding RNAs perform multiple regulatory functions in cells, and their exogenous mimics are widely used in research and experimental therapies to interfere with target gene expression. MicroRNAs (miRNAs) are the most thoroughly investigated representatives of the small RNA family, which includes short interfering RNAs (siRNAs), PIWI-associated RNA (piRNAs), and others. Numerous methods have been adopted for the detection and characterization of small RNAs, which is challenging due to their short length and low level of expression. These include molecular biology methods such as real-time RT-PCR, northern blotting, hybridization to microarrays, cloning and sequencing, as well as single cell miRNA detection by microscopy with in situ hybridization (ISH). In this review, we focus on the ISH method, including its fluorescent version (FISH), and we present recent methodological advances that facilitated its successful adaptation for small RNA detection. We discuss relevant technical aspects as well as the advantages and limitations of ISH. We also refer to numerous applications of small RNA ISH in basic research and molecular diagnostics. PMID:26068454

  1. Method for early detection of cooling-loss events

    DOEpatents

    Bermudez, Sergio A.; Hamann, Hendrik F.; Marianno, Fernando J.

    2015-12-22

    A method of detecting cooling-loss event early is provided. The method includes defining a relative humidity limit and change threshold for a given space, measuring relative humidity in the given space, determining, with a processing unit, whether the measured relative humidity is within the defined relative humidity limit, generating a warning in an event the measured relative humidity is outside the defined relative humidity limit and determining whether a change in the measured relative humidity is less than the defined change threshold for the given space and generating an alarm in an event the change is greater than the defined change threshold.

  2. Method for early detection of cooling-loss events

    DOEpatents

    Bermudez, Sergio A.; Hamann, Hendrik; Marianno, Fernando J.

    2015-06-30

    A method of detecting cooling-loss event early is provided. The method includes defining a relative humidity limit and change threshold for a given space, measuring relative humidity in the given space, determining, with a processing unit, whether the measured relative humidity is within the defined relative humidity limit, generating a warning in an event the measured relative humidity is outside the defined relative humidity limit and determining whether a change in the measured relative humidity is less than the defined change threshold for the given space and generating an alarm in an event the change is greater than the defined change threshold.

  3. Method and apparatus for detecting gem-polyhalogenated hydrocarbons

    DOEpatents

    Anderson, deceased, William G.; Anderson, legal representative, Johanna S.

    1990-01-01

    A method and optrode for detecting gem polyhalogenated hydrocarbons in a sample fluid based on a single phase Fujiwara reaction as provided. The method comprises contacting a reaction mixture with a sample fluid which contains the gem-polyhalogenated hydrocarbons. The reaction mixture comprises an aqueous solution of pyridine or derivative thereof and a hindered nitrogen base. Upon contact a fluorescent and/or chromgenic reaction product forms whose fluorescence and/or absorbance is related to the concentration of gem-polyhalogenated hydrocarbons in the sample fluid.

  4. A graph clustering method for community detection in complex networks

    NASA Astrophysics Data System (ADS)

    Zhou, HongFang; Li, Jin; Li, JunHuai; Zhang, FaCun; Cui, YingAn

    2017-03-01

    Information mining from complex networks by identifying communities is an important problem in a number of research fields, including the social sciences, biology, physics and medicine. First, two concepts are introduced, Attracting Degree and Recommending Degree. Second, a graph clustering method, referred to as AR-Cluster, is presented for detecting community structures in complex networks. Third, a novel collaborative similarity measure is adopted to calculate node similarities. In the AR-Cluster method, vertices are grouped together based on calculated similarity under a K-Medoids framework. Extensive experimental results on two real datasets show the effectiveness of AR-Cluster.

  5. Control of irradiated food: Recent developments in analytical detection methods.

    NASA Astrophysics Data System (ADS)

    Delincée, H.

    1993-07-01

    An overview of recent international efforts, i.e. programmes of "ADMIT" (FAO/IAEA) and of BCR (EC) towards the development of analytical detection methods for radiation processed foods will be given. Some larger collaborative studies have already taken place, e.g. ESR of bones from chicken, prok, beef, frog legs and fish, thermoluminescence of insoluble minerals isolated from herbs and spices, GC analysis of long-chain hydrocarbons derived from the lipid fraction of chicken and other meats, and the microbiological APC/DEFT procedure for spices. These methods could soon be implemented in international standard protocols.

  6. Cepstrum based feature extraction method for fungus detection

    NASA Astrophysics Data System (ADS)

    Yorulmaz, Onur; Pearson, Tom C.; Çetin, A. Enis

    2011-06-01

    In this paper, a method for detection of popcorn kernels infected by a fungus is developed using image processing. The method is based on two dimensional (2D) mel and Mellin-cepstrum computation from popcorn kernel images. Cepstral features that were extracted from popcorn images are classified using Support Vector Machines (SVM). Experimental results show that high recognition rates of up to 93.93% can be achieved for both damaged and healthy popcorn kernels using 2D mel-cepstrum. The success rate for healthy popcorn kernels was found to be 97.41% and the recognition rate for damaged kernels was found to be 89.43%.

  7. A speaker change detection method based on coarse searching

    NASA Astrophysics Data System (ADS)

    Zhang, Xue-yuan; He, Qian-hua; Li, Yan-xiong; He, Jun

    2013-03-01

    The conventional speaker change detection (SCD) method using Bayesian Information Criterion (BIC) has been widely used. However, its performance relies on the choice of penalty factor and suffers from mass calculation. The twostep SCD is less time consuming but generates more detection errors. The limitation of conventional method's performance originates from the two adjacent data windows. We propose a strategy that inserts an interval between the two adjacent fixed-size data windows in each analysis window. The dissimilarity value between the data windows is regarded as the probability of a speaker identity change within the interval area. Then this analysis window is slid along the audio by a large step to locate the areas where speaker change points may appear. Afterwards we only focus on these areas and locate precisely where the change points are. Other areas where a speaker change point unlikely appears are abandoned. The proposed method is computationally efficient and more robust to noise and penalty factor compared with conventional method. Evaluated on the corpus of China Central Television (CCTV) news, the proposed method obtains 74.18% reduction in calculation time and 22.24% improvement in F1-measure compared with the conventional approach.

  8. Steganography forensics method for detecting least significant bit replacement attack

    NASA Astrophysics Data System (ADS)

    Wang, Xiaofeng; Wei, Chengcheng; Han, Xiao

    2015-01-01

    We present an image forensics method to detect least significant bit replacement steganography attack. The proposed method provides fine-grained forensics features by using the hierarchical structure that combines pixels correlation and bit-planes correlation. This is achieved via bit-plane decomposition and difference matrices between the least significant bit-plane and each one of the others. Generated forensics features provide the susceptibility (changeability) that will be drastically altered when the cover image is embedded with data to form a stego image. We developed a statistical model based on the forensics features and used least square support vector machine as a classifier to distinguish stego images from cover images. Experimental results show that the proposed method provides the following advantages. (1) The detection rate is noticeably higher than that of some existing methods. (2) It has the expected stability. (3) It is robust for content-preserving manipulations, such as JPEG compression, adding noise, filtering, etc. (4) The proposed method provides satisfactory generalization capability.

  9. Salient motion detection using proximal robust principal component analysis method

    NASA Astrophysics Data System (ADS)

    Wang, Pengcheng; Chen, Qian; Qian, Weixian; Ren, Kan; Yao, Zheyi; Xu, Fuyuan

    2017-03-01

    The recently proposed robust principal component analysis (RPCA) theory and its derived methods have attracted much attention in many computer vision and machine intelligence applications. From a wide view of these methods, independent motion objects are modeled as pixel-wised sparse or structurally sparse outliers from a highly correlated background signal, and all these methods are implemented under an ℓ1 -penalized optimization. Real data experiments reveal that even if ℓ1-penalty is convex, the optimization sometimes cannot be satisfactorily solved, especially when the signal-to-noise ratio is relatively high. In addition, the unexpected background motion (e.g., periodic or stochastic motion) may also be included. We propose a moving object detection method based on a proximal RPCA along with saliency detection. Convex penalties including low-rank and sparse regularizations are substituted with proximal norms to achieve robust regression. After the foreground candidates have been extracted, a motion saliency map using spatiotemporal filtering is constructed. The foreground objects are then filtered out by dynamically adjusting the penalty parameter according to the corresponding saliency values. Evaluations on challenging video clips and qualitative and quantitative comparisons with several state-of-the-art methods demonstrate that the proposed approach works efficiently and robustly.

  10. Vortex flows in the solar chromosphere. I. Automatic detection method

    NASA Astrophysics Data System (ADS)

    Kato, Y.; Wedemeyer, S.

    2017-05-01

    Solar "magnetic tornadoes" are produced by rotating magnetic field structures that extend from the upper convection zone and the photosphere to the corona of the Sun. Recent studies show that these kinds of rotating features are an integral part of atmospheric dynamics and occur on a large range of spatial scales. A systematic statistical study of magnetic tornadoes is a necessary next step towards understanding their formation and their role in mass and energy transport in the solar atmosphere. For this purpose, we develop a new automatic detection method for chromospheric swirls, meaning the observable signature of solar tornadoes or, more generally, chromospheric vortex flows and rotating motions. Unlike existing studies that rely on visual inspections, our new method combines a line integral convolution (LIC) imaging technique and a scalar quantity that represents a vortex flow on a two-dimensional plane. We have tested two detection algorithms, based on the enhanced vorticity and vorticity strength quantities, by applying them to three-dimensional numerical simulations of the solar atmosphere with CO5BOLD. We conclude that the vorticity strength method is superior compared to the enhanced vorticity method in all aspects. Applying the method to a numerical simulation of the solar atmosphere reveals very abundant small-scale, short-lived chromospheric vortex flows that have not been found previously by visual inspection.

  11. ASR damage detection in concrete from ultrasonic methods

    NASA Astrophysics Data System (ADS)

    Gong, Peng; Patton, Mark E.; Greve, David W.; Harley, Joel B.; Junker, Warren R.; Liu, Chang; Oppenheim, Irving J.

    2014-03-01

    Alkali-silica reaction (ASR) is a chemical reaction that can occur between alkaline components in cement paste and reactive forms of silica in susceptible aggregates when sufficient moisture is present. The ASR product, known as ASR gel, can cause expansion and cracking that damages the structure. We pass ultrasonic signals through concrete laboratory specimens and use three different ultrasonic methods to detect the onset of ASR damage, or the presence of ASR damage while still at the microscale. Our test specimens are fabricated with aggregate known to be reactive and are then exposed to an aggressive environment to accelerate ASR development. We use swept-sine excitations and obtain pitch-catch records from specimens that have been exposed to the accelerated environment. From this data, we demonstrate an ultrasonic passband method shows high frequency components diminish faster than low frequency components, and therefore the ultrasonic passband shifts to the low frequency side due to ASR damage. The test results also show that the ultrasonic passband is logically related to specimen size. We also demonstrate a stretching factor method is able to track the progress of ASR damage in concrete very well. These methods are shown to be more reliable than attenuation spectrum or attenuation methods that do not detect the ASR damage in concrete at early stages.

  12. A Robust Shape Reconstruction Method for Facial Feature Point Detection.

    PubMed

    Tan, Shuqiu; Chen, Dongyi; Guo, Chenggang; Huang, Zhiqi

    2017-01-01

    Facial feature point detection has been receiving great research advances in recent years. Numerous methods have been developed and applied in practical face analysis systems. However, it is still a quite challenging task because of the large variability in expression and gestures and the existence of occlusions in real-world photo shoot. In this paper, we present a robust sparse reconstruction method for the face alignment problems. Instead of a direct regression between the feature space and the shape space, the concept of shape increment reconstruction is introduced. Moreover, a set of coupled overcomplete dictionaries termed the shape increment dictionary and the local appearance dictionary are learned in a regressive manner to select robust features and fit shape increments. Additionally, to make the learned model more generalized, we select the best matched parameter set through extensive validation tests. Experimental results on three public datasets demonstrate that the proposed method achieves a better robustness over the state-of-the-art methods.

  13. Current perspectives on genetically modified crops and detection methods.

    PubMed

    Kamle, Madhu; Kumar, Pradeep; Patra, Jayanta Kumar; Bajpai, Vivek K

    2017-07-01

    Genetically modified (GM) crops are the fastest adopted commodities in the agribiotech industry. This market penetration should provide a sustainable basis for ensuring food supply for growing global populations. The successful completion of two decades of commercial GM crop production (1996-2015) is underscored by the increasing rate of adoption of genetic engineering technology by farmers worldwide. With the advent of introduction of multiple traits stacked together in GM crops for combined herbicide tolerance, insect resistance, drought tolerance or disease resistance, the requirement of reliable and sensitive detection methods for tracing and labeling genetically modified organisms in the food/feed chain has become increasingly important. In addition, several countries have established threshold levels for GM content which trigger legally binding labeling schemes. The labeling of GM crops is mandatory in many countries (such as China, EU, Russia, Australia, New Zealand, Brazil, Israel, Saudi Arabia, Korea, Chile, Philippines, Indonesia, Thailand), whereas in Canada, Hong Kong, USA, South Africa, and Argentina voluntary labeling schemes operate. The rapid adoption of GM crops has increased controversies, and mitigating these issues pertaining to the implementation of effective regulatory measures for the detection of GM crops is essential. DNA-based detection methods have been successfully employed, while the whole genome sequencing using next-generation sequencing (NGS) technologies provides an advanced means for detecting genetically modified organisms and foods/feeds in GM crops. This review article describes the current status of GM crop commercialization and discusses the benefits and shortcomings of common and advanced detection systems for GMs in foods and animal feeds.

  14. A method for mass candidate detection and an application to liver lesion detection

    NASA Astrophysics Data System (ADS)

    Costa, Maria J.; Tsymbal, Alexey; Nguatem, William; Suehling, Michael; Zhou, S. Kevin; Comaniciu, Dorin

    2011-03-01

    Detection and segmentation of abnormal masses within organs in Computed Tomography (CT) images of patients is of practical importance in computer-aided diagnosis (CAD), treatment planning, and analysis of normal as well as pathological regions. For intervention planning e.g. in radiotherapy the detection of abnormal masses is essential for patient diagnosis, personalized treatment choice and follow-up. The unpredictable nature of disease often makes the detection of the presence, appearance, shape, size and number of abnormal masses a challenging task, which is particularly tedious when performed by hand. Moreover, in cases in which the imaging protocol specifies the administration of a contrast agent, the contrast agent phases at which the patient images are acquired have a dramatic influence on the shape and appearance of the diseased masses. In this paper we propose a method to automatically detect candidate lesions (CLs) in 3D CTs of liver lesions. We introduce a novel multilevel candidate generation method that proves clearly advantageous in a comparative study with a state of the art approach. A learning-based selection module and a candidate fusion module are then introduced to reduce both redundancy and the false positive rate. The proposed workflow is applied to the detection of both hyperdense and hypodense hepatic lesions in all contrast agent phases, with resulting sensitivities of 89.7% and 92% and positive predictive values of 82.6% and 87.6% respectively.

  15. The photometric method of extrasolar planet detection revisited

    NASA Technical Reports Server (NTRS)

    Hale, Alan; Doyle, Laurance R.

    1994-01-01

    We investigate the geometry concerning the photometric method of extrasolar planet detection, i.e., the detection of dimunition of a parent star's brightness during a planetary transit. Under the assumption that planetary orbital inclinations can be defined by a Gaussian with a sigma of 10 deg centered on the parent star's equatorial plane, Monte Carlo simulations suggest that for a given star observed at an inclination of exactly 90 deg, the probability of at least one Earth-sized or larger planet being suitably placed for transits is approximately 4%. This probability drops to 3% for a star observed at an inclination of 80 deg, and is still approximately 0.5% for a star observed at an inclination of 60 deg. If one can select 100 stars with a pre-determined inclination equal or greater than 80 deg, the probability of at least one planet being suitably configured for transits is 95%. The majority of transit events are due to planets in small-a orbits similar to the Earth and Venus; thus, the photometric method in principle is the method best suited for the detection of Earthlike planets. The photometric method also allows for testing whether or not planets can exist within binary systems. This can ge done by selecting binary systems observed at high orbital inclinations, both eclipsing binaries and wider visual binaries. For a 'real-world' example, we look at the alpha Centauri system (i = 79.2 deg). If we assume that the equatorial planes of both components coincide with the system's orbital plane, Monte Carlo simulations suggest that the probability of at least one planet (of either component) being suitably configured for transits is approximately 8%. In conclusion, we present a non-exhaustive list of solar-type stars, both single and within binary systems, which exhibit a high equatorial inclination. These objects may be considered as preliminary candidates for planetary searches via the photometric method.

  16. IR-based method for copper electrolysis short circuit detection

    NASA Astrophysics Data System (ADS)

    Makipaa, Esa; Tanttu, Juha T.; Virtanen, Henri

    1997-04-01

    In the copper electrorefining process short-circuits between the anodes and cathodes are harmful. They cause decreasing production rate and poor cathode copper quality. Short- circuits should be detected and eliminated as soon as possible. Manual inspection methods often take a lot of time and excessive walking on the electrodes can not be avoided. For these reasons there is a lot of interest to develop short-circuit detection and quality control. In this paper an IR based method for short circuit detection is presented. In the case of the short-circuited anode and cathode pair especially cathode bar becomes significantly warmer than bar in the normal condition. Using IR camera mounted on a moving crane these hot spots among the electrodes were easily detected. IR imaging was tested in the harsh conditions of the refinery hall with various crane speeds. Image processing is a tool to interpret the obtained IR images. In this paper an algorithm for searching the locations of the short-circuits in the electrolytic cell using imaging results as test material is proposed. The basic idea of the developed algorithm is first to search and calculate necessary edges and initial lines of the electrolytic cell. The second step is to determine the exact position of each cathode plate in the cell so that using thresholding the location of the short-circuited cathode can be determined. IR imaging combined with image processing has proven to be a superior method for predictive maintenance and process control compared to manual ones in the copper electrorefining process. It also makes it possible to collect valuable information for the quality control purposes.

  17. Error detection for genetic data, using likelihood methods

    SciTech Connect

    Ehm, M.G.; Kimmel, M.; Cottingham, R.W. Jr.

    1996-01-01

    As genetic maps become denser, the effect of laboratory typing errors becomes more serious. We review a general method for detecting errors in pedigree genotyping data that is a variant of the likelihood-ratio test statistic. It pinpoints individuals and loci with relatively unlikely genotypes. Power and significance studies using Monte Carlo methods are shown by using simulated data with pedigree structures similar to the CEPH pedigrees and a larger experimental pedigree used in the study of idiopathic dilated cardiomyopathy (DCM). The studies show the index detects errors for small values of {theta} with high power and an acceptable false positive rate. The method was also used to check for errors in DCM laboratory pedigree data and to estimate the error rate in CEPH chromosome 6 data. The errors flagged by our method in the DCM pedigree were confirmed by the laboratory. The results are consistent with estimated false-positive and false-negative rates obtained using simulation. 21 refs., 5 figs., 2 tabs.

  18. A semiparametric cluster detection method--a comprehensive power comparison with Kulldorff's method.

    PubMed

    Wen, Shihua; Kedem, Benjamin

    2009-12-31

    A semiparametric density ratio method which borrows strength from two or more samples can be applied to moving window of variable size in cluster detection. The method requires neither the prior knowledge of the underlying distribution nor the number of cases before scanning. In this paper, the semiparametric cluster detection procedure is combined with Storey's q-value, a type of controlling false discovery rate (FDR) method, to take into account the multiple testing problem induced by the overlapping scanning windows. It is shown by simulations that for binary data, using Kulldorff's Northeastern benchmark data, the semiparametric method and Kulldorff's method performs similarly well. When the data are not binary, the semiparametric methodology still works in many cases, but Kulldorff's method requires the choices of a correct probability model, namely the correct scan statistic, in order to achieve comparable power as the semiparametric method achieves. Kulldorff's method with an inappropriate probability model may lose power. The semiparametric method proposed in the paper can achieve good power when detecting localized cluster. The method does not require a specific distributional assumption other than the tilt function. In addition, it is possible to adapt other scan schemes (e.g., elliptic spatial scan, flexible shape scan) to search for clusters as well.

  19. A reliable method for detecting complexed DNA in vitro.

    PubMed

    Holladay, C; Keeney, M; Newland, B; Mathew, A; Wang, W; Pandit, A

    2010-12-01

    Quantification of eluted nucleic acids is a critical parameter in characterizing biomaterial based gene-delivery systems. The most commonly used method is to assay samples with an intercalating fluorescent dye such as PicoGreen®. However, this technique was developed for unbound DNA and the current trend in gene delivery is to condense DNA with transfection reagents, which interfere with intercalation. Here, for the first time, the DNA was permanently labeled with the fluorescent dye Cy5 prior to complexation, an alternative technique hypothesized to allow quantification of both bound and unbound DNA. A comparison of the two methods was performed by quantifying the elution of six different varieties of DNA complexes from a model biomaterial (collagen) scaffold. After seven days of elution, the PicoGreen® assay only allowed detection of three types of complexes (those formed using Lipofectin™ and two synthesised copolymers). However, the Cy5 fluorescent labeling technique enabled detection of all six varieties including those formed via common transfection agents poly(ethylene imine), poly-L-lysine and SuperFect™. This allowed reliable quantification of the elution of all these complexes from the collagen scaffold. Thus, while intercalating dyes may be effective and reliable for detecting double-stranded, unbound DNA, the technique described in this work allowed reliable quantification of DNA independent of complexation state.

  20. Microbial detection method based on sensing molecular hydrogen.

    PubMed

    Wilkins, J R; Stoner, G E; Boykin, E H

    1974-05-01

    A simple method for detecting bacteria, based on the time of hydrogen evolution, was developed and tested against various members of the Enterobacteriaceae group. The test system consisted of (i) two electrodes, platinum and a reference electrode, (ii) a buffer amplifier, and (iii) a strip-chart recorder. Hydrogen evolution was measured by an increase in voltage in the negative (cathodic) direction and recorded on a strip-chart recorder. Hydrogen response curves consisted of (i) a lag period, (ii) a period of rapid buildup in potential due to hydrogen, and (iii) a period of decline in potential. A linear relationship was established between inoculum size and the time hydrogen was detected (lag period). Lag times ranged from 1 h for 10(6) cells/ml to 7 h for 10(0) cells/ml. For each 10-fold decrease in inoculum, length of the lag period increased 60 to 70 min. Mean cell concentrations at the time of hydrogen evolution were 10(6)/ml. Based on the linear relationship between inoculum size and lag period, these results indicate the potential application of the hydrogen-sensing method for rapidly detecting coliforms and other gas-producing microorganisms in a variety of clinical, food, and other samples.

  1. Integration of microwave and thermographic NDT methods for corrosion detection

    NASA Astrophysics Data System (ADS)

    Pieper, D.; Donnell, K. M.; Ghasr, M. T.; Kinzel, E. C.

    2014-02-01

    Infrastructure health monitoring is an important issue in the transportation industry. For the case of cement-based structures in particular, detection of corrosion on reinforcing steel bars (rebar) is an ongoing problem for aging infrastructure. There have been a number of techniques that have shown promise in this area including microwave nondestructive testing (NDT) and thermography. Thermography is quite advantageous as it is an established method, and can be utilized for large inspection areas with intuitive results. Typical heat sources include induction heating and flash lamps, but these are not without drawbacks. Microwave nondestructive testing has also been successful at detecting corroded rebar, but at the cost of lengthy scan times. This paper presents an investigation into the potential of utilizing aspects of microwave NDT and thermography to create a hybrid NDT method, herein referred to as Active Microwave Thermography (AMT). AMT takes advantage of the electromagnetically lossy nature of corrosion byproducts and uses microwave energy to induce heat in the corrosion. Subsequently, the resultant heat profile is captured using an infrared camera. This paper presents initial simulations and measurements that highlight the potential of AMT to detect corroded rebar.

  2. Serological versus antigen detection methods for Giardia duodenalis diagnosis.

    PubMed

    Bashir, M; Farid, A; Rabia, I; Mostafa, B; El Amir, A

    2014-12-01

    Giardiasis constitutes an important public health problem in the world. Contamination of the water with fecal materials including viruses and pathogenic protozoa still represents an environmental health hazard, especially in rural areas. The survey study evaluated the relation between seropositivity and some risk factors. Moreover, the study compared between the serological IgG and IgM level and antigen detection methods for the diagnosis of giardiasis. The results indicate that sex distribution and age were the mean risk factors for seroprevelence. In this study, sera samples were employed in sandwich ELISA assay, to detect circulating Giardia antigens. None of the negative control serum samples gave a positive reaction, but cross reaction was encountered with 3 case of Cryptosporidium. The specificity of the assay was 94.830/a. On the other hand, the sensitivity of the Giardia patient's sera was 94.12% which was higher than that of IgG (86.25%) and IgM (87.50%) secretion measurements. In conclusion, antigen detection methods give better and earlier diagnosis for giardiasis can be performed quickly and do not require an experienced and skilled morphologist.

  3. Rapid and robust detection methods for poison and microbial contamination.

    PubMed

    Hoehl, Melanie M; Lu, Peter J; Sims, Peter A; Slocum, Alexander H

    2012-06-27

    Real-time on-site monitoring of analytes is currently in high demand for food contamination, water, medicines, and ingestible household products that were never tested appropriately. Here we introduce chemical methods for the rapid quantification of a wide range of chemical and microbial contaminations using a simple instrument. Within the testing procedure, we used a multichannel, multisample, UV-vis spectrophotometer/fluorometer that employs two frequencies of light simultaneously to interrogate the sample. We present new enzyme- and dye-based methods to detect (di)ethylene glycol in consumables above 0.1 wt % without interference and alcohols above 1 ppb. Using DNA intercalating dyes, we can detect a range of pathogens ( E. coli , Salmonella , V. Cholera, and a model for Malaria) in water, foods, and blood without background signal. We achieved universal scaling independent of pathogen size above 10(4) CFU/mL by taking advantage of the simultaneous measurement at multiple wavelengths. We can detect contaminants directly, without separation, purification, concentration, or incubation. Our chemistry is stable to ± 1% for >3 weeks without refrigeration, and measurements require <5 min.

  4. New High-Accuracy Methods for Automatically Detecting & Tracking CMEs

    NASA Astrophysics Data System (ADS)

    Byrne, Jason; Morgan, H.; Habbal, S. R.

    2012-05-01

    With the large amounts of CME image data available from the SOHO and STEREO coronagraphs, manual cataloguing of events can be tedious and subject to user bias. Therefore automated catalogues, such as CACTus and SEEDS, have been developed in an effort to produce a robust method of detection and analysis of events. Here we present the development of a new CORIMP (coronal image processing) CME detection and tracking technique that overcomes many of the drawbacks of previous methods. It works by first employing a dynamic CME separation technique to remove the static background, and then characterizing CMEs via a multiscale edge-detection algorithm. This allows the inherent structure of the CMEs to be revealed in each image, which is usually prone to spatiotemporal crosstalk as a result of traditional image-differencing techniques. Thus the kinematic and morphological information on each event is resolved with higher accuracy than previous catalogues, revealing CME acceleration and expansion profiles otherwise undetected, and enabling a determination of the varying speeds attained across the span of the CME. The potential for a 3D characterization of the internal structure of CMEs is also demonstrated.

  5. Methods of detecting and counting raptors: A review

    USGS Publications Warehouse

    Fuller, M.R.; Mosher, J.A.; Ralph, C. John; Scott, J. Michael

    1981-01-01

    Most raptors are wide-ranging, secretive, and occur at relatively low densities. These factors, in conjunction with the nocturnal activity of owls, cause the counting of raptors by most standard census and survey efforts to be very time consuming and expensive. This paper reviews the most common methods of detecting and counting raptors. It is hoped that it will be of use to the ever-increasing number of biologists, land-use planners, and managers that must determine the occurrence, density, or population dynamics of raptors. Road counts of fixed station or continuous transect design are often used to sample large areas. Detection of spontaneous or elicited vocalizations, especially those of owls, provides a means of detecting and estimating raptor numbers. Searches for nests are accomplished from foot surveys, observations from automobiles and boats, or from aircraft when nest structures are conspicuous (e.g., Osprey). Knowledge of nest habitat, historic records, and inquiries of local residents are useful for locating nests. Often several of these techniques are combined to help find nest sites. Aerial searches have also been used to locate or count large raptors (e.g., eagles), or those that may be conspicuous in open habitats (e.g., tundra). Counts of birds entering or leaving nest colonies or colonial roosts have been attempted on a limited basis. Results from Christmas Bird Counts have provided an index of the abundance of some species. Trapping and banding generally has proven to be an inefficient method of detecting raptors or estimating their populations. Concentrations of migrants at strategically located points around the world afford the best opportunity to count many rap tors in a relatively short period of time, but the influence of many unquantified variables has inhibited extensive interpretation of these counts. Few data exist to demonstrate the effectiveness of these methods. We believe more research on sampling techniques, rather than complete

  6. Evaluation of nutria (Myocastor coypus) detection methods in Maryland, USA

    USGS Publications Warehouse

    Pepper, Margaret A; Herrmann, Valentine; Hines, James; Nichols, James; Kendrot, Stephen R

    2017-01-01

    Nutria (Myocaster coypus), invasive, semi-aquatic rodents native to South America, were introduced into Maryland near Blackwater National Wildlife Refuge (BNWR) in 1943. Irruptive population growth, expansion, and destructive feeding habits resulted in the destruction of thousands of acres of emergent marshes at and surrounding BNWR. In 2002, a partnership of federal, state and private entities initiated an eradication campaign to protect remaining wetlands from further damage and facilitate the restoration of coastal wetlands throughout the Chesapeake Bay region. Program staff removed nearly 14,000 nutria from five infested watersheds in a systematic trapping and hunting program between 2002 and 2014. As part of ongoing surveillance activities, the Chesapeake Bay Nutria Eradication Project uses a variety of tools to detect and remove nutria. Project staff developed a floating raft, or monitoring platform, to determine site occupancy. These platforms are placed along waterways and checked periodically for evidence of nutria visitation. We evaluated the effectiveness of monitoring platforms and three associated detection methods: hair snares, presence of scat, and trail cameras. Our objectives were to (1) determine if platform placement on land or water influenced nutria visitation rates, (2) determine if the presence of hair snares influenced visitation rates, and (3) determine method-specific detection probabilities. Our analyses indicated that platforms placed on land were 1.5–3.0 times more likely to be visited than those placed in water and that platforms without snares were an estimated 1.7–3.7 times more likely to be visited than those with snares. Although the presence of snares appears to have discouraged visitation, seasonal variation may confound interpretation of these results. Scat was the least effective method of determining nutria visitation, while hair snares were as effective as cameras. Estimated detection probabilities provided by occupancy

  7. Topological Methods for Pattern Detection in Climate Data

    NASA Astrophysics Data System (ADS)

    Muszynski, G.; Kurlin, V.; Morozov, D.; Prabhat, M.

    2016-12-01

    We address the problem of detecting extreme weather phenomena (called Atmospheric Rivers) in climate datasets. Atmospheric Rivers (ARs) are narrow filaments of concentrated water vapour in the atmosphere whose presence has been connected to major flooding events along the West Coast of North America (California, US) and Western Europe (the United Kingdom). The purpose of this research is to analyze large, high-dimensional climate datasets using Topological Data Analysis (TDA). TDA is a new area on the interface between Topology and Computer Science. Topology studies shapes and properties of geometric objects that are preserved under continuous deformations. TDA provides efficient tools for computing topological properties that are stable under perturbations of noisy data. The state-of-the-art detection methods of ARs use threshold parameters based on fields of Integrated Water Vapour (IWV) data on a fixed grid, while we develop a resolution and threshold independent method. We have refactored the connected component labeling step in AR detection to employ union-find data structure to determine connectedness. For this purpose, we store each component of the graph as a subset of a dataset. Then, by adding the edges one at a time and maintaining components above a variable threshold, we update the volume of all connected components (the sum of values at all nodes in the component) to see the change in topology and geometry along threshold value. We have also implemented a procedure to compute the topological skeleton of the AR and a more accurate method to compute the AR width. We will integrate these improvements with the union-find algorithm to explore the robustness of the AR shape characteristics (length, width, geometric connectivity) as we systematically vary IWV thresholds. Preliminary results indicate that the AR detection procedure can be made more robust (compared to earlier approaches) by incorporating topological ideas. We will present results on the

  8. Detection of selective antibacterial peptides by the Polarity Profile method.

    PubMed

    Polanco, Carlos; Buhse, Thomas; Samaniego, José Lino; Castañón-González, Jorge Alberto

    2013-01-01

    Antimicrobial peptides occupy a prominent place in the production of pharmaceuticals, because of their effective contribution to the protection of the immune system against almost all types of pathogens. These peptides are thoroughly studied by computational methods designed to shed light on their main functions. In this paper, we propose a computational approach, named the Polarity Profile method that represents an improvement to the former Polarity Index method. The Polarity Profile method is very effective in detecting the subgroup of antibacterial peptides called selective cationic amphipathic antibacterial peptides (SCAAP) that show high toxicity towards bacterial membranes and exhibit almost zero toxicity towards mammalian cells. Our study was restricted to the peptides listed in the antimicrobial peptides database (APD2) of December 19, 2012. Performance of the Polarity Profile method is demonstrated through a comparison to the former Polarity Index method by using the same sets of peptides. The efficiency of the Polarity Profile method exceeds 85% taking into account the false positive and/or false negative peptides.

  9. Detection method for avian influenza viruses in water.

    PubMed

    Rönnqvist, Maria; Ziegler, Thedi; von Bonsdorff, Carl-Henrik; Maunula, Leena

    2012-03-01

    Recent events have shown that humans may become infected with some pathogenic avian influenza A viruses (AIV). Since soil and water, including lakes, rivers, and seashores, may be contaminated by AIV excreted by birds, effective methods are needed for monitoring water for emerging viruses. Combining water filtration with molecular methods such as PCR is a fast and effective way for detecting viruses. The objective of this study was to apply a convenient method for the detection of AIV in natural water samples. Distilled water and lake, river, and seawater were artificially contaminated with AIV (H5N3) and passed through a filter system. AIV was detected from filter membrane by real-time RT-PCR. The performance of Zetapor, SMWP, and Sartobind D5F membranes in recovering influenza viruses was first evaluated using contaminated distilled water. SWMP, which gave the highest virus recoveries, was then compared with a pre-filter combined GF/F filter membrane in a trial using natural water samples. In this study, the cellulose membrane SMWP was found to be practical for recovery of AIVs in water. Viral yields varied between 62.1 and 65.9% in distilled water and between 1 and 16.7% in natural water samples. The borosilicate glass membrane GF/F combined with pre-filter was also feasible in filtering natural water samples with viral yields from 1.98 to 7.33%. The methods described can be used for monitoring fresh and seawater samples for the presence of AIV and to determine the source of AIV transmission in an outbreak situation.

  10. Comparison of two different methods of detecting residual caries

    PubMed Central

    Kütük, Zeynep Bilge; Ergin, Esra; Yalçın Çakır, Filiz; Gürgan, Sevil

    2017-01-01

    Objectives The aim of this study was to investigate the ability of the fluorescence-aided caries excavation (FACE) device to detect residual caries by comparing conventional methods in vivo. Materials and Methods A total of 301 females and 202 males with carious teeth participated in this study. The cavity preparations were done by grade 4 (Group 1, 154 teeth), grade 5 (Group 2, 176 teeth), and postgraduate (Group 3, 173 teeth) students. After caries excavation using a handpiece and hand instruments, the presence of residual caries was evaluated by 2 investigators who were previously calibrated for visual-tactile assessment with and without magnifying glasses and trained in the use of a FACE device. The tooth number, cavity type, and presence or absence of residual caries were recorded. The data were analyzed using the Chi-square test, the Fisher's Exact test, or the McNemar test as appropriate. Kappa statistics was used for calibration. In all tests, the level of significance was set at p = 0.05. Results Almost half of the cavities prepared were Class II (Class I, 20.9%; Class II, 48.9%; Class III, 20.1%; Class IV, 3.4%; Class V, 6.8%). Higher numbers of cavities left with caries were observed in Groups 1 and 2 than in Group 3 for all examination methods. Significant differences were found between visual inspection with or without magnifying glasses and inspection with a FACE device for all groups (p < 0.001). More residual caries were detected through inspection with a FACE device (46.5%) than through either visual inspection (31.8%) or inspection with a magnifying glass (37.6%). Conclusions Within the limitations of this study, the FACE device may be an effective method for the detection of residual caries. PMID:28194364

  11. Subsurface Cavity Detection by Using Integrated Geophysical Methods

    NASA Astrophysics Data System (ADS)

    Aykaç, Sinem; Rezzan Ozerk, Zeynep; Işıkdeniz Şerifoǧlu, Betül; Bihter Demirci, Büşra; Timur, Emre; Çakir, Korhan

    2016-04-01

    Global warming experienced in recent years in Turkey has led to a severe drought around the Konya Plain in central Anatolia .As a result, excessive amount of ground water was drawn in the region for the sustainability of agricultural activities. So, five small-scale shallow depth sinkholes have occured at different times, at an average interval between 400-450 m. in the study area; Konya-Atlantı. Generally, sinkholes formation occurres among natural processes has turned into disasters caused by humans due to excessive use of groundwater. Consequently, investigations were carried out within a partnership research programme on cavity detection and ground penetration radar, microgravity and multi-frequency electromagnetic methods were jointly utilized. . Exact locations and dimensions of two possible hidden cavities were determined by using these multidisciplinary methods. Keywords: Cavity;Ground-penetrating radar;Konya;Microgravimetry;Multi-frequency electromagnetic method.

  12. Massively parallel sequencing, a new method for detecting adventitious agents.

    PubMed

    Onions, David; Kolman, John

    2010-05-01

    There has been an upsurge of interest in developing new veterinary and human vaccines and, in turn, this has involved the development of new mammalian and insect cell substrates. Excluding adventitious agents from these cells can be problematic, particularly for cells derived from species with limited virological investigation. Massively parallel sequencing is a powerful new method for the identification of viruses and other adventitious agents, without prior knowledge of the nature of the agent. We have developed methods using random priming to detect viruses in the supernatants from cell substrates or in virus seed stocks. Using these methods we have recently discovered a new parvovirus in bovine serum. When applied to sequencing the transcriptome, massively parallel sequencing can reveal latent or silent infections. Enormous amounts of data are developed in this process usually between 100 and 400 Mbp. Consequently, sophisticated bioinformatic algorithms are required to analyse and verify virus targets.

  13. Methods and systems for detection of ice formation on surfaces

    NASA Technical Reports Server (NTRS)

    Alfano, Robert R. (Inventor); Wang, Wubao (Inventor); Sztul, Henry (Inventor); Budansky, Yury (Inventor)

    2007-01-01

    A system for detecting ice formation on metal, painted metal and other material surfaces can include a transparent window having an exterior surface upon which ice can form; a light source and optics configured and arranged to illuminate the exterior surface of the window from behind the exterior surface; and a detector and optics configured and arranged to receive light backscattered by the exterior surface and any ice disposed on the exterior surface and determine the thickness of the ice layer. For example, the system can be used with aircraft by placing one or more windows in the wings of the aircraft. The system is used for a novel optical method for real-time on-board detection and warning of ice formation on surfaces of airplanes, unmanned aerial vehicles (UAVs), and other vehicles and stationary structures to improve their safety and operation.

  14. System and Method for Outlier Detection via Estimating Clusters

    NASA Technical Reports Server (NTRS)

    Iverson, David J. (Inventor)

    2016-01-01

    An efficient method and system for real-time or offline analysis of multivariate sensor data for use in anomaly detection, fault detection, and system health monitoring is provided. Models automatically derived from training data, typically nominal system data acquired from sensors in normally operating conditions or from detailed simulations, are used to identify unusual, out of family data samples (outliers) that indicate possible system failure or degradation. Outliers are determined through analyzing a degree of deviation of current system behavior from the models formed from the nominal system data. The deviation of current system behavior is presented as an easy to interpret numerical score along with a measure of the relative contribution of each system parameter to any off-nominal deviation. The techniques described herein may also be used to "clean" the training data.

  15. Note: A manifold ranking based saliency detection method for camera

    NASA Astrophysics Data System (ADS)

    Zhang, Libo; Sun, Yihan; Luo, Tiejian; Rahman, Mohammad Muntasir

    2016-09-01

    Research focused on salient object region in natural scenes has attracted a lot in computer vision and has widely been used in many applications like object detection and segmentation. However, an accurate focusing on the salient region, while taking photographs of the real-world scenery, is still a challenging task. In order to deal with the problem, this paper presents a novel approach based on human visual system, which works better with the usage of both background prior and compactness prior. In the proposed method, we eliminate the unsuitable boundary with a fixed threshold to optimize the image boundary selection which can provide more precise estimations. Then, the object detection, which is optimized with compactness prior, is obtained by ranking with background queries. Salient objects are generally grouped together into connected areas that have compact spatial distributions. The experimental results on three public datasets demonstrate that the precision and robustness of the proposed algorithm have been improved obviously.

  16. Method of detecting luminescent target ions with modified magnetic microspheres

    DOEpatents

    Shkrob, Ilya A; Kaminski, Michael D

    2014-05-13

    This invention provides methods of using modified magnetic microspheres to extract target ions from a sample in order to detect their presence in a microfluidic environment. In one or more embodiments, the microspheres are modified with molecules on the surface that allow the target ions in the sample to form complexes with specific ligand molecules on the microsphere surface. In one or more embodiments, the microspheres are modified with molecules that sequester the target ions from the sample, but specific ligand molecules in solution subsequently re-extract the target ions from the microspheres into the solution, where the complexes form independent of the microsphere surface. Once the complexes form, they are exposed to an excitation wavelength light source suitable for exciting the target ion to emit a luminescent signal pattern. Detection of the luminescent signal pattern allows for determination of the presence of the target ions in the sample.

  17. Methods for use in detecting seismic waves in a borehole

    DOEpatents

    West, Phillip B.; Fincke, James R.; Reed, Teddy R.

    2007-02-20

    The invention provides methods and apparatus for detecting seismic waves propagating through a subterranean formation surrounding a borehole. In a first embodiment, a sensor module uses the rotation of bogey wheels to extend and retract a sensor package for selective contact and magnetic coupling to casing lining the borehole. In a second embodiment, a sensor module is magnetically coupled to the casing wall during its travel and dragged therealong while maintaining contact therewith. In a third embodiment, a sensor module is interfaced with the borehole environment to detect seismic waves using coupling through liquid in the borehole. Two or more of the above embodiments may be combined within a single sensor array to provide a resulting seismic survey combining the optimum of the outputs of each embodiment into a single data set.

  18. Parameters of explosives detection through tagged neutron method

    NASA Astrophysics Data System (ADS)

    Bagdasaryan, Kh. E.; Batyaev, V. F.; Belichenko, S. G.; Bestaev, R. R.; Gavryuchenkov, A. V.; Karetnikov, M. D.

    2015-06-01

    The potentialities of tagged neutron method (TNM) for explosives detection are examined on the basis of an idealized geometrical model. The model includes ING-27 14 MeV neutron generator with a built-in α-detector, a LYSO γ-detector and samples of material to be identified of approximately 0.3 kg each: explosives imitators (trinitrotoluene - TNT, tetryl, RDX and ammonium nitrate), legal materials (sugar, water, silk and polyethylene). The samples were unshielded or shielded by a paper layer of various thicknesses. The experimental data were interpreted by numerical simulation using a Poisson distribution of signals with the statistical parameters defined experimentally. The detection parameters were obtained by a pattern classification theory and a Bayes classifier.

  19. Performance Assessment Method for a Forged Fingerprint Detection Algorithm

    NASA Astrophysics Data System (ADS)

    Shin, Yong Nyuo; Jun, In-Kyung; Kim, Hyun; Shin, Woochang

    The threat of invasion of privacy and of the illegal appropriation of information both increase with the expansion of the biometrics service environment to open systems. However, while certificates or smart cards can easily be cancelled and reissued if found to be missing, there is no way to recover the unique biometric information of an individual following a security breach. With the recognition that this threat factor may disrupt the large-scale civil service operations approaching implementation, such as electronic ID cards and e-Government systems, many agencies and vendors around the world continue to develop forged fingerprint detection technology, but no objective performance assessment method has, to date, been reported. Therefore, in this paper, we propose a methodology designed to evaluate the objective performance of the forged fingerprint detection technology that is currently attracting a great deal of attention.

  20. Single Molecule Detection in Solution: Methods and Applications

    NASA Astrophysics Data System (ADS)

    Zander, Christoph; Enderlein, Jorg; Keller, Richard A.

    2002-07-01

    The detection of single molecules opens up new horizons in analytical chemistry, biology and medicine. This discipline, which belongs to the expanding field of nanoscience, has been rapidly emerging over the last ten years. This handbook provides a thorough overview of the field. It begins with basics of single molecule detection in solution, describes methods and devices (fluorescense correlation spectroscopy, surface enhanced Raman scattering, sensors, especially dyes, screening techniques, especially confocal laser scanning microscopy). In the second part, various applications in life sciences and medicine provide the latest research results. This modern handbook is a highly accessible reference for a broad community from advanced researchers, specialists and company professionals in physics, spectroscopy, biotechnology, analytical chemistry, and medicine. Written by leading authorities in the field, it is timely and fills a gap - up to now there exists no handbook concerning this theme.

  1. Two passive microwave prototype methods for hail detection

    NASA Astrophysics Data System (ADS)

    Laviola, Sante; Beauchamp, Jim; Ferraro, Ralph; Levizzani, Vincenzo

    2015-04-01

    During previous decades, relationships between many geophysical variables and the radiometric measurements in the microwave bands were translated into several satellite-based algorithms. Recently, several studies have revealed a high correlation between the occurrence of hail and the microwave brightness temperature depression in convective clouds. In this work, we propose two independent prototype methods for the detection of hail on the basis of the AMSU-B/MHS brightness temperature variation. The first method was developed through the use of collocated satellite and surface hail reports over the continental US for a 10-year period (2000-2009). Compared with the surface observations, the algorithm detects approximately nearly 40% of hail occurrences. The simple threshold algorithms are then used to generate a hail climatology based on all available AMSU observations during 2000-2011 and stratified in several ways, including total hail occurrence on a daily (diurnal cycle), monthly, and total annual basis. The second hail detection algorithm is an improvement of the preexistent MicroWave Cloud Classification (MWCC) method, which exploits the properties of the water vapor channels on board the AMSU-B/MHS to classify the cloud type (stratiform/convection) by estimating the cloud top altitude. Using the results of the MWCC, deep convections were correlated with selected hailstorm events over Europe, South America and the US. The 10-year AMSU-B/MHS observations used for the first method were also employed to refine the algorithm criteria. The hail detector of the MWCC is based on a probabilistic model, which calculates the probability associated with each pixel by following the growth law of the hailstones. The validation results over the US have demonstrated the high correlation between the two methods and the surface hail reports showing a remarkable agreement in terms of POD and FAR. Reference Ferraro, R., Beauchamp J., Cecil D., Heymsfield G., 2014: A prototype

  2. Assessment of three methods for detection of ultrasound artifacts.

    PubMed

    King, Deirdre M; Hangiandreou, Nicholas J; Tradup, Donald J; Stekel, Scott F

    2011-11-01

    The purpose of this work is to measure the performance (sensitivity and specificity) of three different visually based methods of detecting ultrasound artifacts using dynamic clips obtained with a liquid phantom. It is important to detect the presence of these non uniformities as early as possible, so they can be assessed, tracked, and addressed well before clinical image quality is impacted. A total of 28 transducers of varying models containing a single artificial artifact created by stretching thin filaments across the transducer face were prepared. A second set of 28 matching transducers contained no artifacts. A 10 s clip was recorded of a dynamic speckle pattern from a custom liquid phantom ("dynamic clip"). A single-frame image was obtained by computing the median values at each pixel location over all frames of the clip ("median image"). This single-frame median image was then subtracted from a baseline image previously obtained with no induced artifact ("subtracted median"). All images were evaluated by six observers. The mean sensitivity and specificity with 95% exact binomial confidence intervals for the three artifact detection methods were estimated. Evaluation time and observer confidence were recorded. Both single-frame median and subtracted median images had a higher sensitivity than the dynamic clip. Overall the subtracted median images had the highest sensitivity of 97%, while maintaining a high specificity of 92%. Observers identified artifacts in the shortest time and with the highest confidence with this method. The subtracted median method removed the original structural variations and non-uniformities, and reduced the likelihood of false-positives. From the three methods assessed in this study, subtracted median images allow detection of artifacts with very good sensitivity and specificity, low image evaluation times, and a high degree of observer confidence, making these ideal for routine QC. For acceptance testing, where there are no

  3. Evaluation of two detection methods of microorganisms in platelet concentrates.

    PubMed

    Albertoni, G; Andrade, S S; Araújo, P R B; Carvalho, F O; Girão, M J B C; Barreto, J A

    2011-12-01

    The performance of a bacterial 16S ribosomal DNA real-time polymerase chain reaction (PCR) assay was evaluated and validated with an automated culture system to determine its use for screening of platelet concentrates (PCs). PCs were spiked with suspensions of Escherichia coli, Serratia marcescens, Staphylococcus epidermidis and St. aureus at 1, 10, and 100 colony-forming units (CFUs) mL and stored for 5 days. DNA amplification was performed using real-time PCR. The BacT/ALERT was used as a reference method and samples were inoculated into an aerobic culture bottle; for the PCR assay, aliquots were drawn from all (spiked) PCs on days 0 to 5 of storage. Real-time PCR detected only the gram-positive bacteria in PCs spiked with low bacterial titres (1 CFU mL) after 48 h; however, it was able to detect all positive samples in PCs spiked with 10 CFU mL of either gram-positive or gram-negative bacteria after 48 h. In addition, real-time PCR detected all positive samples in PCs spiked with high gram-positive bacterial titres (100 CFU mL) after 24 h. On the other hand, the BacT/ALERT system showed positive results in all samples within 24 h. The BacT/ALERT method is more sensitive and should continue to be the gold standard for identifying bacterial contaminations in blood samples. The real-time PCR approach can be used for the screening of PCs for microbial detection before they are released from blood centres or shortly before they are used in blood transfusion, and thus allow an extended shelf life of the platelets. © 2011 The Authors. Transfusion Medicine © 2011 British Blood Transfusion Society.

  4. Auscultatory percussion: a simple method to detect pleural effusion.

    PubMed

    Guarino, J R; Guarino, J C

    1994-02-01

    To assess a new technique for the detection of free pleural fluid. 118 consecutive inpatients with radiologic evidence of free pleural fluid and a control group of 175 randomly selected inpatients were examined over a three-year period in a prospective blind study by auscultatory percussion (AP) for evidence of pleural effusion. The cutoff in the percussion note by AP is strikingly loud and sharp at the fluid level and allows precise delineation of even minimal amounts of pleural fluid. The fluid level was measured in reference to the last rib. The criterion for detection of pleural effusion by AP was a demonstrable horizontal fluid level at the sound cutoff across the posterior hemithorax above the last rib that shifted with lateral tilt. A general medical and surgical university-affiliated teaching Veterans Affairs hospital. All inpatients were eligible. Ready availability of examiners was essential. Rotating third- and fourth-year medical students, residents, and senior staff members participated. None. 113 of the 118 patients with radiologic evidence of pleural effusion had a distinct horizontal fluid level above the last rib that shifted with lateral tilt (sensitivity = 95.8%). None of the 175 control patients examined at random showed evidence of pleural effusion by AP examination, which was confirmed by chest radiography (specificity = 100%). Nine of the 175 patients without radiologic evidence of pleural effusion had elevated diaphragms that simulated a fluid level in the examination by AP. Each of the nine patients, however, had no shift in the level with lateral tilt. Subpulmonic effusions were readily displaced and identified by this method of AP. Examination by AP is highly sensitive and specific for the detection of free pleural fluid, even in the presence of obesity, thickened pleura, lung masses, pneumonia, and associated lung disease. The examination correlates closely with standard and lateral decubitus chest radiography. Pleural effusion

  5. Fire ant-detecting canines: a complementary method in detecting red imported fire ants.

    PubMed

    Lin, Hui-Min; Chi, Wei-Lien; Lin, Chung-Chi; Tseng, Yu-Ching; Chen, Wang-Ting; Kung, Yu-Ling; Lien, Yi-Yang; Chen, Yang-Yuan

    2011-02-01

    In this investigation, detection dogs are trained and used in identifying red imported fire ants, Solenopsis invicta Buren, and their nests. The methodology could assist in reducing the frequency and scope of chemical treatments for red imported fire ant management and thus reduce labor costs and chemical use as well as improve control and quarantine efficiency. Three dogs previously trained for customs quarantine were retrained to detect the scents of red imported fire ants. After passing tests involving different numbers of live red imported fire ants and three other ant species--Crematogaster rogenhoferi Mayr, Paratrechina longicornis Latreille, and Pheidole megacephala F.--placed in containers, ajoint field survey for red imported fire ant nests by detection dogs and bait traps was conducted to demonstrate their use as a supplement to conventional detection methods. The most significant findings in this report are (1) with 10 or more red imported fire ants in scent containers, the dogs had >98% chance in tracing the red imported fire ant. Upon the introduction of other ant species, the dogs still achieved on average, a 93% correct red imported fire ant indication rate. Moreover, the dogs demonstrated great competence in pinpointing emerging and smaller red imported fire ant nests in red imported fire ant-infested areas that had been previously confirmed by bait trap stations. (2) Along with the bait trap method, we also discovered that approximately 90% of red imported fire ants foraged within a distance of 14 m away from their nests. The results prove detection dogs to be most effective for red imported fire ant control in areas that have been previously treated with pesticides and therefore containing a low density of remaining red imported fire ant nests. Furthermore, as a complement to other red imported fire ant monitoring methods, this strategy will significantly increase the efficacy of red imported fire ant control in cases of individual mount treatment.

  6. Comparison of conventional staining methods and monoclonal antibody-based methods for Cryptosporidium oocyst detection.

    PubMed Central

    Arrowood, M J; Sterling, C R

    1989-01-01

    The sensitivity and specificity of seven microscopy-based Cryptosporidium oocyst detection methods were compared after application to unconcentrated fecal smears. The seven methods were as follows: (i) a commercial acid-fast (AF) stain (VOLU-SOL) method, (ii) Truant auramine-rhodamine (AR) stain method, (iii) fluorescein-conjugated C1B3 monoclonal antibody (MAb) direct fluorescence method, (iv) OW3 MAb indirect fluorescence method, (v) biotinylated OW3 indirect fluorescence method, (vi) biotinylated OW3-indirect diaminobenzidine (DAB) method, and (vii) biotinylated OW3-aminoethylcarbazole (AEC) method. A total of 281 randomly collected Formalin-fixed fecal samples (submitted to the Maricopa County Health Department, Phoenix, Ariz.) and 30 known positives (Formalin-fixed and K2Cr2O7-preserved stools from our laboratory) were examined in a blind test; 32 of 311 samples (10.3%) were confirmed positive. Of the confirmed positives, 40.6% were identified by the AF method, 93.8% were identified by the AR method, 93.8% were identified by the C1B3 method, 81.3% were identified by the OW3-DAB method, 71.9% were identified by the OW3-AEC method, 100% were identified by the OW3 indirect fluorescence method, and 100% were identified by the biotinylated OW3 indirect fluorescence method. False-positives were encountered by the AF and AR methods (52.0 and 85.7% specificity, respectively), while no false-positives encountered by the MAb-based methods. Oocysts in infected tissue sections were easily detected by the MAb-based methods. Images PMID:2475523

  7. Genome Fusion Detection: a novel method to detect fusion genes from SNP-array data.

    PubMed

    Thieme, Sebastian; Groth, Philip

    2013-03-15

    Fusion genes result from genomic rearrangements, such as deletions, amplifications and translocations. Such rearrangements can also frequently be observed in cancer and have been postulated as driving event in cancer development. to detect them, one needs to analyze the transition region of two segments with different copy number, the location where fusions are known to occur. Finding fusion genes is essential to understanding cancer development and may lead to new therapeutic approaches. Here we present a novel method, the Genomic Fusion Detection algorithm, to predict fusion genes on a genomic level based on SNP-array data. This algorithm detects genes at the transition region of segments with copy number variation. With the application of defined constraints, certain properties of the detected genes are evaluated to predict whether they may be fused. We evaluated our prediction by calculating the observed frequency of known fusions in both primary cancers and cell lines. We tested a set of cell lines positive for the BCR-ABL1 fusion and prostate cancers positive for the TMPRSS2-ERG fusion. We could detect the fusions in all positive cell lines, but not in the negative controls.

  8. Automated Detection Method of Slow Slip Events in Southwest Japan

    NASA Astrophysics Data System (ADS)

    Kimura, T.; Hirose, H.; Obara, K.; Kimura, H.

    2010-12-01

    In the Nankai subduction zone, southwest Japan, various types of slow earthquakes have been detected using dense seismic and geodetic observation networks such as Hi-net operated by the National Research Institute for Earth Science and Disaster Prevention. Short-term slow slip events (SSEs) which last for several days are detected as crustal deformation by using borehole tiltmeters and strainmeters, and usually accompanied by seismic slow earthquakes such as nonvolcanic deep low-frequency tremor. These coupled phenomena are called episodic tremor and slip (ETS). In previous studies on ETS events in southwest Japan, short-term SSEs have been identified manually consulting with the seismic tremor data. However, in order to clarify the relationship between geodetic SSEs and seismic tremor objectively, an SSE detection method independent of the tremor data is necessary. In this study, we develop a new automated method that identifies signals caused by SSEs and estimates the source model using ground tilt data. Our method is composed of two phases, estimation of the SSE model and identification of SSE. In the model estimation phase, we assume that an SSE must occur in the analyzed time period, and observed ground tilt contains a response to an SSE, background linear trend, random-walk noise, and white noise. An SSE is modeled as a uniform slip on a rectangular fault with a time-invariant slip-rate. We estimate an optimum source model of the possible SSE using the Kalman filter for linear parameters such as total slip and grid-search method for nonlinear parameters such as fault location, origin time and duration. In the identification phase, another model is estimated from the same tilt data with an assumption that no SSE occurs. The tilt changes modeled as an SSE in the estimation phase is evaluated by comparison between the models with and without SSE on the basis of AIC. Then a robustness test is carried and the model is identified as an SSE. We applied the automated

  9. Spectroscopic methods for detection of impurities in water

    NASA Astrophysics Data System (ADS)

    Strashnikova, Natalia V.; Papiashvili, Nona; Cohen-Luria, Rivka; Mark, Shlomo; Shilon, Guy; Khankin, Daniel; Kalisky, Yehoshua; Kalisky, Ofra; Parola, Abraham H.

    2011-11-01

    Optical photoluminescence spectroscopic method for detection of impurities, hazardous materials, pesticides, and pollutants in water resources, both qualitatively and quantitatively, is presented. The method is based on synchronous fluorescence spectroscopy (SFS) of organic aromatic compounds, or poly-aromatic hydrocarbons (PAH), and is carried out by following simultaneously their excitation and emission spectra. The full excitation emission matrix (EEM) generated in this way provides a 2-D and 3-D fluorescence map of the tested sample and the diagonals through the axes origin provide the synchronous fluorescence spectra at a constant wavelengths differences between the emission and excitation wavelengths, thus enabling multitude components identification. This map contains all the relevant spectroscopic information of the tested sample, and serves as a unique "fingerprint" with a very specific and accurate identification. When compared with pre-determined spectra and calibration curves from a "databank", there is a one-toone correspondence between the image and the specific compound, and it can be identified accurately both qualitatively and quantitatively. This method offers several significant advantages, and it provides a sensitive (ppm detection level), accurate and simple spectroscopic tool to monitor impurities and pollutants in water. The design and performance of the spectrofluorimeter prototype, as well as the software development and analysis of chemical organic compounds and mixtures in water will be discussed in this paper.

  10. a Probabilistic Embedding Clustering Method for Urban Structure Detection

    NASA Astrophysics Data System (ADS)

    Lin, X.; Li, H.; Zhang, Y.; Gao, L.; Zhao, L.; Deng, M.

    2017-09-01

    Urban structure detection is a basic task in urban geography. Clustering is a core technology to detect the patterns of urban spatial structure, urban functional region, and so on. In big data era, diverse urban sensing datasets recording information like human behaviour and human social activity, suffer from complexity in high dimension and high noise. And unfortunately, the state-of-the-art clustering methods does not handle the problem with high dimension and high noise issues concurrently. In this paper, a probabilistic embedding clustering method is proposed. Firstly, we come up with a Probabilistic Embedding Model (PEM) to find latent features from high dimensional urban sensing data by "learning" via probabilistic model. By latent features, we could catch essential features hidden in high dimensional data known as patterns; with the probabilistic model, we can also reduce uncertainty caused by high noise. Secondly, through tuning the parameters, our model could discover two kinds of urban structure, the homophily and structural equivalence, which means communities with intensive interaction or in the same roles in urban structure. We evaluated the performance of our model by conducting experiments on real-world data and experiments with real data in Shanghai (China) proved that our method could discover two kinds of urban structure, the homophily and structural equivalence, which means clustering community with intensive interaction or under the same roles in urban space.

  11. Damage detection in composite materials using Lamb wave methods

    NASA Astrophysics Data System (ADS)

    Kessler, Seth S.; Spearing, S. Mark; Soutis, Constantinos

    2002-04-01

    Cost-effective and reliable damage detection is critical for the utilization of composite materials. This paper presents part of an experimental and analytical survey of candidate methods for in situ damage detection of composite materials. Experimental results are presented for the application of Lamb wave techniques to quasi-isotropic graphite/epoxy test specimens containing representative damage modes, including delamination, transverse ply cracks and through-holes. Linear wave scans were performed on narrow laminated specimens and sandwich beams with various cores by monitoring the transmitted waves with piezoceramic sensors. Optimal actuator and sensor configurations were devised through experimentation, and various types of driving signal were explored. These experiments provided a procedure capable of easily and accurately determining the time of flight of a Lamb wave pulse between an actuator and sensor. Lamb wave techniques provide more information about damage presence and severity than previously tested methods (frequency response techniques), and provide the possibility of determining damage location due to their local response nature. These methods may prove suitable for structural health monitoring applications since they travel long distances and can be applied with conformable piezoelectric actuators and sensors that require little power.

  12. Current and Prospective Methods for Plant Disease Detection

    PubMed Central

    Fang, Yi; Ramasamy, Ramaraja P.

    2015-01-01

    Food losses due to crop infections from pathogens such as bacteria, viruses and fungi are persistent issues in agriculture for centuries across the globe. In order to minimize the disease induced damage in crops during growth, harvest and postharvest processing, as well as to maximize productivity and ensure agricultural sustainability, advanced disease detection and prevention in crops are imperative. This paper reviews the direct and indirect disease identification methods currently used in agriculture. Laboratory-based techniques such as polymerase chain reaction (PCR), immunofluorescence (IF), fluorescence in-situ hybridization (FISH), enzyme-linked immunosorbent assay (ELISA), flow cytometry (FCM) and gas chromatography-mass spectrometry (GC-MS) are some of the direct detection methods. Indirect methods include thermography, fluorescence imaging and hyperspectral techniques. Finally, the review also provides a comprehensive overview of biosensors based on highly selective bio-recognition elements such as enzyme, antibody, DNA/RNA and bacteriophage as a new tool for the early identification of crop diseases. PMID:26287253

  13. Conventional, molecular methods and biomarkers molecules in detection of septicemia

    PubMed Central

    Arabestani, Mohammad Reza; Rastiany, Sahar; Kazemi, Sima; Mousavi, Seyed Masoud

    2015-01-01

    Sepsis is a leading cause of morbidity and mortality in hospitalized patients worldwide and based on studies, 30–40% of all cases of severe sepsis and septic shock results from the blood stream infections (BSIs). Identifying of the disease, performing laboratory tests, and consequently treatment are factors that required for optimum management of BSIs. In addition, applying precise and immediate identification of the etiologic agent is a prerequisite for specific antibiotic therapy of pathogen and thereby decreasing mortality rates. The diagnosis of sepsis is difficult because clinical signs of sepsis often overlap with other noninfectious cases of systemic inflammation. BSIs are usually diagnosed by performing a series of techniques such as blood cultures, polymerase chain reaction-based methods, and biomarkers of sepsis. Extremely time-consuming even to take up to several days is a major limitation of conventional methods. In addition, yielding false-negative results due to fastidious and slow-growing microorganisms and also in case of antibiotic pretreated samples are other limitations. In comparison, molecular methods are capable of examining a blood sample obtained from suspicious patient with BSI and gave the all required information to prescribing antimicrobial therapy for detected bacterial or fungal infections immediately. Because of an emergency of sepsis, new methods are being developed. In this review, we discussed about the most important sepsis diagnostic methods and numbered the advantage and disadvantage of the methods in detail. PMID:26261822

  14. Development of a molecular detection method for naphthalene degrading pseudomonads

    SciTech Connect

    Silva, M.C.

    1993-01-01

    A new combined method for detection of naphthalene degrading pseudomonads from soil has been developed. After direct extraction from soil using a lysozyme/sodium dodecyl sulfate/freeze thaw method and rapid purification through gel electrophoresis, DNA was amplified through polymerase chain reaction (PCR) using primers directed against the nahR regulatory gene present in plasmid NAH7 of Pseudomonas putida G7. The resulting product was detected with a reverse dot blot protocol improving sensitivity ten-fold over traditional ethidium bromide staining of agarose gel electrophoresis, with positive signals starting at the 10[sup 3] CFUs/g soil level. This method was successful in detecting indigenous bacteria from subsurface sediment of a naphthalene contaminated site in New York State, and that similar combined approaches could be developed for other soil borne genetic markers. A study was also carried out on how culture conditions, and other variables that modulate a cell's physiology bias a PCR amplification against generating a representative specimen profile. Two Pseudomonas putida G7 nahR alleles were constructed in pUC19 that differ solely in a 31 bp internal segment whose sequence has been inverted. After PCR amplification, the products could be distinguished. When an Escherichia coli strain carrying one nahR allele is submitted to varying growth conditions, the consequences can be ascertained through co-amplification with a strain carrying the other allele and subsequent restriction analysis. Sublethal levels of tetracycline or growth in minimal medium made the PCR target in these cells relatively less amplifiable. However, cells in stationary phase displayed improved amplifiability while cells grown at 42[degrees]C were equally amplifiable as compared to cells grown at 37[degrees]C. These results suggest that mixed populations containing cells in different physiological states may not be representatively amplified by PCR.

  15. Whole-tree methods for detecting differential diversification rates.

    PubMed

    Chan, Kai M A; Moore, Brian R

    2002-12-01

    Prolific cladogenesis, adaptive radiation, species selection, key innovations, and mass extinctions are a few examples of biological phenomena that lead to differential diversification among lineages. Central to the study of differential diversification rates is the ability to distinguish chance variation from that which requires deterministic explanation. To detect diversification rate variation among lineages, we propose a number of methods that incorporate information on the topological distribution of species diversity from all internal nodes of a phylogenetic tree. These whole-tree methods (M(Pi), M(Sigma), and M(R)) are explicitly connected to a null model of random diversification--the equal-rates Markov (ERM) random branching model--and an alternative model of differential diversification: M(Pi) is based on the product of individual nodal ERM probabilities; M(Sigma) is based on the sum of individual nodal ERM probabilities, and M(R) is based on a transformation of ERM probabilities that corresponds to a formalized system that orders trees by their relative symmetry. These methods have been implemented in a freely available computer program, SYMMETREE, to detect clades with variable diversification rates, thereby allowing the study of biological processes correlated with and possibly causal to shifts in diversification rate. Application of these methods to several published phylogenies demonstrates their ability to contend with relatively large, incompletely resolved trees. These topology-based methods do not require estimates of relative branch lengths, which should facilitate the analysis of phylogenies, such as supertrees, for which such data are unreliable or unavailable.

  16. Detection and characterisation of anthropogenic pieces by magnetic method

    NASA Astrophysics Data System (ADS)

    Nodot, Emilie; Munschy, Marc; Benevent, Pierre

    2013-04-01

    Human activities have let many anthropogenic objects buried under our feet. Some of these like explosive devices left after the World Wars turn out to be a threat to safety or environment. Others must be perfectly localised in case of construction work, for example gas pipe. Geophysics and more specifically magnetic cartography (many of these items are magnetic) can obviously help to locate them. We already use this method on daily basis to detect UXO (unexploded ordnance) but less than 10% of the unearthed objects are actually bombs or shells. Detection and mostly characterisation methods must be improved in order to reduce this proportion. On the field there are a few things we can do to increase data qualities. Characterisation may be improved by multiple scale prospections. We search a large area with our usual and rather fast method then we achieve high definition cartographies of small interesting areas (upon the object to characterise). In the case of measurements in an urban environment for example, data are distorted. The traffic (train, tramway, cars…) produces temporal variations of the magnetic field. This effect can be lessened, sometimes even removed by the use of a fixed scalar magnetic sensor. Data treatment is another key as regards the characterisation. Tools such as analytic signal or derivative are frequently used at the first degree. We will see that in a synthetic case the second and third degree bring even more information. A new issue appeared recently about pipes. Can we localise very precisely (less than 10 cm uncertainty) a gas pipe? Horizontally we can but due to our inversion method we still have troubles with the depth accuracy. Our final concern is about the amplitude of some anomalies. Potential methods equations are based on the fact that the anomaly norm must be minor to magnetic field norm. Sometimes this is not the case but vector magnetometry is a lead to solve this problem.

  17. Advances in Laboratory Methods for Detection and Typing of Norovirus

    PubMed Central

    2014-01-01

    Human noroviruses are the leading cause of epidemic and sporadic gastroenteritis across all age groups. Although the disease is usually self-limiting, in the United States norovirus gastroenteritis causes an estimated 56,000 to 71,000 hospitalizations and 570 to 800 deaths each year. This minireview describes the latest data on laboratory methods (molecular, immunological) for norovirus detection, including real-time reverse transcription-quantitative PCR (RT-qPCR) and commercially available immunological assays as well as the latest FDA-cleared multi-gastrointestinal-pathogen platforms. In addition, an overview is provided on the latest nomenclature and molecular epidemiology of human noroviruses. PMID:24989606

  18. Immunological screening method to detect specific translation products.

    PubMed Central

    Broome, S; Gilbert, W

    1978-01-01

    We describe a very sensitive method to detect as antigens the presence of specific proteins within phage plaques or bacterial colonies. We coat plastic sheets with antibody molecules, expose the sheet to lysed bacteria so that a released antigen can bind, and then label the immobilized antigen with radioiodinated antibodies. Thus, the antigen is sandwiched between the antibodies attached to the plastic sheet and those carrying the radioactive label. Autoradiography then shows the positions of antigen-containing colonies or phage plaques. A few molecules of antigen released from each bacterial cell generatean adequate signal. Images PMID:96441

  19. Detection of fuze defects by image-processing methods

    SciTech Connect

    Chung, M.J.

    1988-03-01

    This paper describes experimental studies of the detection of mechanical defects by the application of computer-processing methods to real-time radiographic images of fuze assemblies. The experimental results confirm that a new algorithm developed at Materials Research Laboratory has potential for the automatic inspection of these assemblies and of others that contain discrete components. The algorithm was applied to images that contain a range of grey levels and has been found to be tolerant to image variations encountered under simulated production conditions.

  20. Radioisotope Detection Device and Methods of Radioisotope Collection

    DOEpatents

    Tranter, Troy J.; Oertel, Christopher P.; Giles, John R.; Mann, Nicholas R.; McIlwain, Michael E.

    2011-04-12

    A device for collection of radionuclides includes a mixture of a polymer, a fluorescent organic scintillator and a chemical extractant. A radionuclide detector system includes a collection device comprising a mixture of a polymer, a fluorescent agent and a selective ligand. The system includes at least one photomultiplier tube (PMT). A method of detecting radionuclides includes providing a collector device comprising a mixture comprising a polymer, a fluorescent organic scintillator and a chemical extractant. An aqueous environment is exposed to the device and radionuclides are collected from the environment. Radionuclides can be concentrated within the device.

  1. Method for Real-Time Model Based Structural Anomaly Detection

    NASA Technical Reports Server (NTRS)

    Smith, Timothy A. (Inventor); Urnes, James M., Sr. (Inventor); Reichenbach, Eric Y. (Inventor)

    2015-01-01

    A system and methods for real-time model based vehicle structural anomaly detection are disclosed. A real-time measurement corresponding to a location on a vehicle structure during an operation of the vehicle is received, and the real-time measurement is compared to expected operation data for the location to provide a modeling error signal. A statistical significance of the modeling error signal to provide an error significance is calculated, and a persistence of the error significance is determined. A structural anomaly is indicated, if the persistence exceeds a persistence threshold value.

  2. Oceanic eddy detection and lifetime forecast using machine learning methods

    NASA Astrophysics Data System (ADS)

    Ashkezari, Mohammad D.; Hill, Christopher N.; Follett, Christopher N.; Forget, Gaël.; Follows, Michael J.

    2016-12-01

    We report a novel altimetry-based machine learning approach for eddy identification and characterization. The machine learning models use daily maps of geostrophic velocity anomalies and are trained according to the phase angle between the zonal and meridional components at each grid point. The trained models are then used to identify the corresponding eddy phase patterns and to predict the lifetime of a detected eddy structure. The performance of the proposed method is examined at two dynamically different regions to demonstrate its robust behavior and region independency.

  3. Method for flow cytometric detection of Listeria monocytogenes in milk.

    PubMed Central

    Donnelly, C W; Baigent, G J

    1986-01-01

    This report describes a method for the detection of Listeria monocytogenes in raw milk by flow cytometric analysis of fluorescently labeled bacterial populations. The use of immunofluorescence in combination with measures of DNA content by propidium iodide labeling and size by light scattering enabled specific identification of L. monocytogenes from Streptococcus faecalis, Streptococcus agalactiae, Streptococcus uberis, Staphylococcus epidermidis, and Staphylococcus hyicus. Additional specific resolution of L. monocytogenes populations was achieved through selective enrichment of raw milk in Listeria enrichment broth. These procedures should permit the rapid screening of milk and other food samples for L. monocytogenes and eliminate many of the short-comings associated with conventional fluorescent-antibody procedures. PMID:3096202

  4. Method For Detecting The Presence Of A Ferromagnetic Object

    DOEpatents

    Roybal, Lyle G.

    2000-11-21

    A method for detecting a presence or an absence of a ferromagnetic object within a sensing area may comprise the steps of sensing, during a sample time, a magnetic field adjacent the sensing area; producing surveillance data representative of the sensed magnetic field; determining an absolute value difference between a maximum datum and a minimum datum comprising the surveillance data; and determining whether the absolute value difference has a positive or negative sign. The absolute value difference and the corresponding positive or negative sign thereof forms a representative surveillance datum that is indicative of the presence or absence in the sensing area of the ferromagnetic material.

  5. Microbial detection method based on sensing molecular hydrogen

    NASA Technical Reports Server (NTRS)

    Wilkins, J. R.; Stoner, G. E.; Boykin, E. H.

    1974-01-01

    An approach involving the measurement of hydrogen evolution by test organisms was used to detect and enumerate various members of the Enterobacteriaceae group. The experimental setup for measuring hydrogen evolution consisted of a test tube containing two electrodes plus broth and organisms. The test tube was kept in a water bath at a temperature of 35 C. It is pointed out that the hydrogen-sensing method, coupled with the pressure transducer technique reported by Wilkins (1974) could be used in various experiments in which gas production by microorganisms is being measured.

  6. Methods and systems for detecting abnormal digital traffic

    DOEpatents

    Goranson, Craig A [Kennewick, WA; Burnette, John R [Kennewick, WA

    2011-03-22

    Aspects of the present invention encompass methods and systems for detecting abnormal digital traffic by assigning characterizations of network behaviors according to knowledge nodes and calculating a confidence value based on the characterizations from at least one knowledge node and on weighting factors associated with the knowledge nodes. The knowledge nodes include a characterization model based on prior network information. At least one of the knowledge nodes should not be based on fixed thresholds or signatures. The confidence value includes a quantification of the degree of confidence that the network behaviors constitute abnormal network traffic.

  7. Method for detecting pollutants. [through chemical reactions and heat treatment

    NASA Technical Reports Server (NTRS)

    Rogowski, R. S.; Richards, R. R.; Conway, E. J. (Inventor)

    1976-01-01

    A method is described for detecting and measuring trace amounts of pollutants of the group consisting of ozone, nitrogen dioxide, and carbon monoxide in a gaseous environment. A sample organic solid material that will undergo a chemical reaction with the test pollutant is exposed to the test environment and thereafter, when heated in the temperature range of 100-200 C., undergoes chemiluminescence that is measured and recorded as a function of concentration of the test pollutant. The chemiluminescence of the solid organic material is specific to the pollutant being tested.

  8. Benchmarks for measurement of duplicate detection methods in nucleotide databases.

    PubMed

    Chen, Qingyu; Zobel, Justin; Verspoor, Karin

    2017-01-08

    Duplication of information in databases is a major data quality challenge. The presence of duplicates, implying either redundancy or inconsistency, can have a range of impacts on the quality of analyses that use the data. To provide a sound basis for research on this issue in databases of nucleotide sequences, we have developed new, large-scale validated collections of duplicates, which can be used to test the effectiveness of duplicate detection methods. Previous collections were either designed primarily to test efficiency, or contained only a limited number of duplicates of limited kinds. To date, duplicate detection methods have been evaluated on separate, inconsistent benchmarks, leading to results that cannot be compared and, due to limitations of the benchmarks, of questionable generality. In this study, we present three nucleotide sequence database benchmarks, based on information drawn from a range of resources, including information derived from mapping to two data sections within the UniProt Knowledgebase (UniProtKB), UniProtKB/Swiss-Prot and UniProtKB/TrEMBL. Each benchmark has distinct characteristics. We quantify these characteristics and argue for their complementary value in evaluation. The benchmarks collectively contain a vast number of validated biological duplicates; the largest has nearly half a billion duplicate pairs (although this is probably only a tiny fraction of the total that is present). They are also the first benchmarks targeting the primary nucleotide databases. The records include the 21 most heavily studied organisms in molecular biology research. Our quantitative analysis shows that duplicates in the different benchmarks, and in different organisms, have different characteristics. It is thus unreliable to evaluate duplicate detection methods against any single benchmark. For example, the benchmark derived from UniProtKB/Swiss-Prot mappings identifies more diverse types of duplicates, showing the importance of expert curation, but

  9. Comparison of Event Detection Methods for Centralized Sensor Networks

    NASA Technical Reports Server (NTRS)

    Sauvageon, Julien; Agogiono, Alice M.; Farhang, Ali; Tumer, Irem Y.

    2006-01-01

    The development of an Integrated Vehicle Health Management (IVHM) for space vehicles has become a great concern. Smart Sensor Networks is one of the promising technologies that are catching a lot of attention. In this paper, we propose to a qualitative comparison of several local event (hot spot) detection algorithms in centralized redundant sensor networks. The algorithms are compared regarding their ability to locate and evaluate the event under noise and sensor failures. The purpose of this study is to check if the ratio performance/computational power of the Mote Fuzzy Validation and Fusion algorithm is relevant compare to simpler methods.

  10. Optimization of Quantitative PCR Methods for Enteropathogen Detection.

    PubMed

    Liu, Jie; Gratz, Jean; Amour, Caroline; Nshama, Rosemary; Walongo, Thomas; Maro, Athanasia; Mduma, Esto; Platts-Mills, James; Boisen, Nadia; Nataro, James; Haverstick, Doris M; Kabir, Furqan; Lertsethtakarn, Paphavee; Silapong, Sasikorn; Jeamwattanalert, Pimmada; Bodhidatta, Ladaporn; Mason, Carl; Begum, Sharmin; Haque, Rashidul; Praharaj, Ira; Kang, Gagandeep; Houpt, Eric R

    2016-01-01

    Detection and quantification of enteropathogens in stool specimens is useful for diagnosing the cause of diarrhea but is technically challenging. Here we evaluate several important determinants of quantification: specimen collection, nucleic acid extraction, and extraction and amplification efficiency. First, we evaluate the molecular detection and quantification of pathogens in rectal swabs versus stool, using paired flocked rectal swabs and whole stool collected from 129 children hospitalized with diarrhea in Tanzania. Swabs generally yielded a higher quantification cycle (Cq) (average 29.7, standard deviation 3.5 vs. 25.3 ± 2.9 from stool, P<0.001) but were still able to detect 80% of pathogens with a Cq < 30 in stool. Second, a simplified total nucleic acid (TNA) extraction procedure was compared to separate DNA and RNA extractions and showed 92% (318/344) sensitivity and 98% (951/968) specificity, with no difference in Cq value for the positive results (ΔCq(DNA+RNA-TNA) = -0.01 ± 1.17, P = 0.972, N = 318). Third, we devised a quantification scheme that adjusts pathogen quantity to the specimen's extraction and amplification efficiency, and show that this better estimates the quantity of spiked specimens than the raw target Cq. In sum, these methods for enteropathogen quantification, stool sample collection, and nucleic acid extraction will be useful for laboratories studying enteric disease.

  11. Optimization of Quantitative PCR Methods for Enteropathogen Detection

    PubMed Central

    Liu, Jie; Gratz, Jean; Amour, Caroline; Nshama, Rosemary; Walongo, Thomas; Maro, Athanasia; Mduma, Esto; Platts-Mills, James; Boisen, Nadia; Nataro, James; Haverstick, Doris M.; Kabir, Furqan; Lertsethtakarn, Paphavee; Silapong, Sasikorn; Jeamwattanalert, Pimmada; Bodhidatta, Ladaporn; Mason, Carl; Begum, Sharmin; Haque, Rashidul; Praharaj, Ira; Kang, Gagandeep; Houpt, Eric R.

    2016-01-01

    Detection and quantification of enteropathogens in stool specimens is useful for diagnosing the cause of diarrhea but is technically challenging. Here we evaluate several important determinants of quantification: specimen collection, nucleic acid extraction, and extraction and amplification efficiency. First, we evaluate the molecular detection and quantification of pathogens in rectal swabs versus stool, using paired flocked rectal swabs and whole stool collected from 129 children hospitalized with diarrhea in Tanzania. Swabs generally yielded a higher quantification cycle (Cq) (average 29.7, standard deviation 3.5 vs. 25.3 ± 2.9 from stool, P<0.001) but were still able to detect 80% of pathogens with a Cq < 30 in stool. Second, a simplified total nucleic acid (TNA) extraction procedure was compared to separate DNA and RNA extractions and showed 92% (318/344) sensitivity and 98% (951/968) specificity, with no difference in Cq value for the positive results (ΔCq(DNA+RNA-TNA) = -0.01 ± 1.17, P = 0.972, N = 318). Third, we devised a quantification scheme that adjusts pathogen quantity to the specimen’s extraction and amplification efficiency, and show that this better estimates the quantity of spiked specimens than the raw target Cq. In sum, these methods for enteropathogen quantification, stool sample collection, and nucleic acid extraction will be useful for laboratories studying enteric disease. PMID:27336160

  12. CHROMagar Salmonella Detection Test Kit. Performance Tested Method 020502.

    PubMed

    Webb, Katana; Ritter, Vicki

    2009-01-01

    BBL CHROMagar Salmonella was evaluated by an external food testing laboratory for the recovery of Salmonella in peanut butter using the U.S. Food and Drug Administration's Bacteriological Analytical Manual (FDA-BAM) procedure. The peanut butter was found to be negative for the presence of Salmonella and, therefore, was seeded with heat-stressed Salmonella at target concentrations of 0.2 and 2 CFU/25 g. The Salmonella-seeded samples remained at room temperature for 14 days before analysis to stabilize the Salmonella in the food environment. Twenty 25 g test portions from each seeded level and five 25 g samples of uninoculated control samples were processed using enrichment broths as outlined in the FDA-BAM procedure. BBL CHROMagar Salmonella-prepared plates were evaluated with the FDA reference method media (bismuth sulfite, xylose lysine desoxycholate, and Hektoen enteric agars). Fractionally positive results were obtained from the lower inoculum level of peanut butter samples. Five positive cultures were recovered from both the BBL CHROMagar Salmonella and reference methods. The two methods gave identical results for all cultures resulting in a method agreement of 100%. McNemar's chi2 test, which assesses the evidence for difference in marginal proportions between two methods, could not be evaluated because it requires one or more discrepant cultures. However, because there were no discrepant cultures, the marginal proportions for the two methods were identical; therefore, there is no evidence of a difference between the methods. This study demonstrates that the results from BBL CHROMagar Salmonella are comparable to the three reference method media for the detection of Salmonella in peanut butter using the FDA-BAM procedures.

  13. Probability of detection models for eddy current NDE methods

    SciTech Connect

    Rajesh, S. N.

    1993-04-30

    The development of probability of detection (POD) models for a variety of nondestructive evaluation (NDE) methods is motivated by a desire to quantify the variability introduced during the process of testing. Sources of variability involved in eddy current methods of NDE include those caused by variations in liftoff, material properties, probe canting angle, scan format, surface roughness and measurement noise. This thesis presents a comprehensive POD model for eddy current NDE. Eddy current methods of nondestructive testing are used widely in industry to inspect a variety of nonferromagnetic and ferromagnetic materials. The development of a comprehensive POD model is therefore of significant importance. The model incorporates several sources of variability characterized by a multivariate Gaussian distribution and employs finite element analysis to predict the signal distribution. The method of mixtures is then used for estimating optimal threshold values. The research demonstrates the use of a finite element model within a probabilistic framework to the spread in the measured signal for eddy current nondestructive methods. Using the signal distributions for various flaw sizes the POD curves for varying defect parameters have been computed. In contrast to experimental POD models, the cost of generating such curves is very low and complex defect shapes can be handled very easily. The results are also operator independent.

  14. SAS molecular tests Salmonella detection kit. Performance tested method 021202.

    PubMed

    Bapanpally, Chandra; Montier, Laura; Khan, Shah; Kasra, Akif; Brunelle, Sharon L

    2014-01-01

    The SAS Molecular tests Salmonella Detection method, a Loop-mediated Isothermal Amplification method, performed as well as or better than the U.S. Department of Agriculture-Food Safety Inspection Service Microbiology Laboratory Guidebook and the U.S. Food and Drug Administration Bacteriological Analytical Manual reference methods for ground beef, beef trim, ground turkey, chicken carcass rinses, bagged mixed lettuce, and fresh spinach. The ground beef (30% fat, 25 g test portion), poultry matrixes and leafy greens were validated in a 6-7 h enrichment, and ground beef (30% fat, 375 g composite test portion) and beef trim (375 g composite test portion) were validated in a 16-20 h enrichment. The method performance for meat and leafy green matrixes was shown to be acceptable under conditions of co-enrichment with Escherichia coli 0157. Thus, after a short 6-7 h co-enrichment step, ground beef, beef trim, lettuce, and spinach can be tested for both Salmonella and E. coli O157. Inclusivity and exclusivity testing revealed no false negatives and no false positives among the 100 Salmonella serovars and 30 non-Salmonella species examined. The method was shown to be robust when enrichment time, DNA extract hold time, and DNA volume were varied.

  15. Methods for detection of Clostridium botulinum toxin in foods.

    PubMed

    Sharma, Shashi K; Whiting, Richard C

    2005-06-01

    Botulism is a deadly disease caused by ingestion of the preformed neurotoxin produced from the anaerobic spore-forming bacteria Clostridium botulinum. Botulinum neurotoxins are the most poisonous toxins known and have been a concern in the food industry for a long time. Therefore, rapid identification of botulinum neurotoxin using molecular and biochemical techniques is an essential component in the establishment of coordinated laboratory response systems and is the focus of current research and development. Because of the extreme toxicity of botulinum neurotoxin, some confirmatory testing with the mouse bioassay is still necessary, but rapid methods capable of screening large numbers of samples are also needed. This review is focused on the development of several detection methods for botulinum neurotoxins in foods.

  16. Methods for detecting and correcting for population stratification.

    PubMed

    Edwards, Todd L; Gao, Xiaoyi

    2012-04-01

    Population stratification (PS) is a primary consideration in studies of the genetic determinants of human traits. Failure to control for it may lead to confounding, causing a study to fail for lack of significant results or resources to be wasted following false-positive signals. Here we review historical and current approaches for addressing PS when performing genetic association studies in human populations. We describe methods for detecting the presence of PS including global and local ancestry methods. We also describe approaches for accounting for PS when calculating association statistics, such that measures of association are not confounded. This is particularly important since many traits are being examined in minority populations, populations that may inherently feature PS. © 2012 by John Wiley & Sons, Inc.

  17. NON-DESTRUCTIVE METHOD AND MEANS FOR FLAW DETECTION

    DOEpatents

    Hochschild, R.

    1959-03-10

    BS>An improved method is presented for the nondestructive detection of flaws in olectrictilly conductivc articles using magnetic field. According to thc method a homogoneous mignetic field is established in the test article;it right angle" to the artyicle. A probe is aligned with its axis transverse to the translates so hat th4 probe scans the surface of the test article while the axis of the robe is transverse to the direction of translation of the article. In this manner any output current obtained in thc probe is an indication of the size and location of a flaw in the article under test, with a miiiimum of signal pick- up in the probe from the established magnetic field.

  18. An efficient method for facial component detection in thermal images

    NASA Astrophysics Data System (ADS)

    Paul, Michael; Blanik, Nikolai; Blazek, Vladimir; Leonhardt, Steffen

    2015-04-01

    A method to detect certain regions in thermal images of human faces is presented. In this approach, the following steps are necessary to locate the periorbital and the nose regions: First, the face is segmented from the background by thresholding and morphological filtering. Subsequently, a search region within the face, around its center of mass, is evaluated. Automatically computed temperature thresholds are used per subject and image or image sequence to generate binary images, in which the periorbital regions are located by integral projections. Then, the located positions are used to approximate the nose position. It is possible to track features in the located regions. Therefore, these regions are interesting for different applications like human-machine interaction, biometrics and biomedical imaging. The method is easy to implement and does not rely on any training images or templates. Furthermore, the approach saves processing resources due to simple computations and restricted search regions.

  19. Immunoanalysis Methods for the Detection of Dioxins and Related Chemicals

    PubMed Central

    Tian, Wenjing; Xie, Heidi Qunhui; Fu, Hualing; Pei, Xinhui; Zhao, Bin

    2012-01-01

    With the development of biotechnology, approaches based on antibodies, such as enzyme-linked immunosorbent assay (ELISA), active aryl hydrocarbon immunoassay (Ah-I) and other multi-analyte immunoassays, have been utilized as alternatives to the conventional techniques based on gas chromatography and mass spectroscopy for the analysis of dioxin and dioxin-like compounds in environmental and biological samples. These screening methods have been verified as rapid, simple and cost-effective. This paper provides an overview on the development and application of antibody-based approaches, such as ELISA, Ah-I, and multi-analyte immunoassays, covering the sample extraction and cleanup, antigen design, antibody preparation and immunoanalysis. However, in order to meet the requirements for on-site fast detection and relative quantification of dioxins in the environment, further optimization is needed to make these immuno-analytical methods more sensitive and easy to use. PMID:23443395

  20. Methods and apparatus for rotor blade ice detection

    DOEpatents

    LeMieux, David Lawrence

    2006-08-08

    A method for detecting ice on a wind turbine having a rotor and one or more rotor blades each having blade roots includes monitoring meteorological conditions relating to icing conditions and monitoring one or more physical characteristics of the wind turbine in operation that vary in accordance with at least one of the mass of the one or more rotor blades or a mass imbalance between the rotor blades. The method also includes using the one or more monitored physical characteristics to determine whether a blade mass anomaly exists, determining whether the monitored meteorological conditions are consistent with blade icing; and signaling an icing-related blade mass anomaly when a blade mass anomaly is determined to exist and the monitored meteorological conditions are determined to be consistent with icing.

  1. Simple method for detection of mutations causing hereditary fructose intolerance.

    PubMed

    Kullberg-Lindh, C; Hannoun, C; Lindh, M

    2002-11-01

    Aldolase B is critical for sugar metabolism, and a catalytic deficiency due to mutations in its gene may result in hereditary fructose intolerance (HFI) syndrome, with hypoglycaemia and severe abdominal symptoms. This report describes two cases of HFI, which were identified by intravenous fructose tolerance test and a new RFLP (restriction fragment length polymorphism) test that detects the two most common mutations, A149P and A174D. The method includes PCR of a 224-base-pair segment of exon 5, a subsequent 3 h incubation with Cac8I and agarose electrophoresis, which reveals either or both of the mutations in one single reaction. The method might be useful for screening of these mutations, which may account for more than 70% of the mutations causing HFI.

  2. Comparison of Methods to Detect HIV Dual Infection

    PubMed Central

    Smith, Davey; Little, Susan; Cheng, Pok Man; Jordan, Parris; Ignacio, Caroline; Richman, Douglas; Pond, Sergei Kosakovsky

    2010-01-01

    Abstract Current methods to detect intraclade HIV dual infection are poorly suited for determining its prevalence in large cohorts. To investigate the potential of ultra-deep sequencing to screen for dual infection, we compared it to bulk sequence-based synonymous mixture index and the current standard of single genome sequencing. The synonymous mixture index identified samples likely to harbor dual infection, while ultra-deep sequencing captured more intra-host viral diversity than single genome sequencing at approximately 40% of the cost and 20% of the laboratory and analysis time. The synonymous mixture index and ultra-deep sequencing are promising methods for rapid and cost-effective systematic identification of HIV dual infection. PMID:20954840

  3. A reliable method for detecting complexed DNA in vitro

    NASA Astrophysics Data System (ADS)

    Holladay, C.; Keeney, M.; Newland, B.; Mathew, A.; Wang, W.; Pandit, A.

    2010-12-01

    Quantification of eluted nucleic acids is a critical parameter in characterizing biomaterial based gene-delivery systems. The most commonly used method is to assay samples with an intercalating fluorescent dye such as PicoGreen®. However, this technique was developed for unbound DNA and the current trend in gene delivery is to condense DNA with transfection reagents, which interfere with intercalation. Here, for the first time, the DNA was permanently labeled with the fluorescent dye Cy5 prior to complexation, an alternative technique hypothesized to allow quantification of both bound and unbound DNA. A comparison of the two methods was performed by quantifying the elution of six different varieties of DNA complexes from a model biomaterial (collagen) scaffold. After seven days of elution, the PicoGreen® assay only allowed detection of three types of complexes (those formed using Lipofectin™ and two synthesised copolymers). However, the Cy5 fluorescent labeling technique enabled detection of all six varieties including those formed via common transfection agents poly(ethylene imine), poly-l-lysine and SuperFect™. This allowed reliable quantification of the elution of all these complexes from the collagen scaffold. Thus, while intercalating dyes may be effective and reliable for detecting double-stranded, unbound DNA, the technique described in this work allowed reliable quantification of DNA independent of complexation state.Quantification of eluted nucleic acids is a critical parameter in characterizing biomaterial based gene-delivery systems. The most commonly used method is to assay samples with an intercalating fluorescent dye such as PicoGreen®. However, this technique was developed for unbound DNA and the current trend in gene delivery is to condense DNA with transfection reagents, which interfere with intercalation. Here, for the first time, the DNA was permanently labeled with the fluorescent dye Cy5 prior to complexation, an alternative technique

  4. Detection of urinary tract infections by rapid methods.

    PubMed Central

    Pezzlo, M

    1988-01-01

    A review of rapid urine screens for detection of bacteriuria and pyuria demonstrates a number of available alternatives to the culture method. Selection of one or more of these systems for routine use is dependent upon the laboratory and the patient population being tested. The laboratory approach to the diagnosis of urinary tract infection should consider the clinical diagnosis of the patient whenever possible. Keeping in mind that quantitative urine cultures alone cannot be used to detect infection in some patient populations unless lower colony counts are considered, a rapid screen may be a more practical approach. It has become accepted that 10(5) CFU/ml can no longer be used as the standard for all patient groups, that pyuria often is important in making the diagnosis of a urinary tract infection, and that most of the rapid screens are more sensitive than the culture method at 10(5) CFU/ml. Presently, no one approach can be recommended for all laboratories and all patient groups. However, each diagnostic laboratory should select one approach which is best for its situation. It is not practical, efficient, or cost effective to define a protocol for each possible clinical condition; however, all should be considered when developing a protocol. This protocol should be compatible with the patient population and communicated to the physicians. Use of a rapid screen should be beneficial to the patient, the physician, and the laboratory. PMID:3058296

  5. Microgravity method for detection of abandoned mines in New Jersey

    SciTech Connect

    Ghatge, S.L. )

    1993-03-01

    The microgravity method has been used to detect two shallow, subsurface abandoned mines in northern New Jersey. Synthetic models simulated the expected gravity anomalies in the two areas. The first site, Lawrence Iron Mine, tested the applicability of microgravity for abandoned-mine detection. Two profile lines were laid out at right angles to the strike of the magnetite deposit in an amphibolite host rock. The broad gravity lows (magnitude 0.04 and 0.07 mGals) on the gravity profiles were modeled to show mine workings about 10 ft square and 5 ft deep that were filled with loose soil. Trenching confirmed the location of the buried mine. At the Schuyler Copper Mine, located in an urban area, data were collected along four parallel profile lines spaced 10 ft apart. An anomalous low (magnitude 0.03 mGals) on the gravity map was modeled and interpreted to be due to an empty vertical shaft. The shaft is more than 60 ft deep, about 12 ft long and 8 to 10 ft wide. It is capped by about 10 ft of unconsolidated material overlying sandstone bedrock. Drilling confirmed the results of the gravity model. The success of the method depended on the depth and size of the mine instrument accuracy, station spacing, station location and elevation control. Minimizing errors due to the instrument drift, station location and station elevation maximized the resolution of the technique.

  6. A Foreign Object Detection Method for Turbine Safety and Reliability

    SciTech Connect

    Allison, Stephen W; Cates, Michael R; Hollerman, William Andrew

    2008-01-01

    A method for detecting blade impacts by foreign object debris (FOD) is described. The rationale derives from the knowledge that FOD is a major source for cost and maintenance penalty as it removes engines from service.1 The method exploits a property of some materials and coatings known as triboluminescence. Triboluminescence is light emission that results when a substance is impacted or fractured.2-4 The goal of this new approach is to accomplish a means of quantifying the received, accumulated flux of incident objects and their energies in order to assess the health of the impacted surface and aid intelligent decisions for maintenance. To effect an impact diagnostic, an amorphous coating of a triboluminescent material is applied to the surface of interest. When a foreign object impacts this surface, the characteristics of the resulting emission will contain information regarding the incident projectile. Some testing in NASA facilities at > 5km/s has indicated the potential for space debris and micrometeorite detection.4 This paper outlines a number of issues that need to be explored in route to a successful implementation for FOD applications.

  7. a Novel and Fast Corner Detection Method for SAR Imagery

    NASA Astrophysics Data System (ADS)

    Jiao, N.; Kang, W.; Xiang, Y.; You, H.

    2017-09-01

    Corners play an important role on image processing, while it is difficult to detect reliable and repeatable corners in SAR images due to the complex property of SAR sensors. In this paper, we propose a fast and novel corner detection method for SAR imagery. First, a local processing window is constructed for each point. We use the local mean of a 3 x 3 mask to represent a single point, which is weighted by a Gaussian template. Then the candidate point is compared with 16 surrounding points in the processing window. Considering the multiplicative property of speckle noise, the similarity measure between the center point and the surrounding points is calculated by the ratio of their local means. If there exist more than M continuous points are different from the center point, then the candidate point is labelled as a corner point. Finally, a selection strategy is implemented by ranking the corner score and employing the non-maxima suppression method. Extreme situations such as isolated bright points are also removed. Experimental results on both simulated and real-world SAR images show that the proposed detector has a high repeatability and a low localization error, compared with other state-of-the-art detectors.

  8. System and method for detection of dispersed broadband signals

    DOEpatents

    Qian, Shie; Dunham, Mark E.

    1999-06-08

    A system and method for detecting the presence of dispersed broadband signals in real time. The present invention utilizes a bank of matched filters for detecting the received dispersed broadband signals. Each matched filter uses a respective robust time template that has been designed to approximate the dispersed broadband signals of interest, and each time template varies across a spectrum of possible dispersed broadband signal time templates. The received dispersed broadband signal x(t) is received by each of the matched filters, and if one or more matches occurs, then the received data is determined to have signal data of interest. This signal data can then be analyzed and/or transmitted to Earth for analysis, as desired. The system and method of the present invention will prove extremely useful in many fields, including satellite communications, plasma physics, and interstellar research. The varying time templates used in the bank of matched filters are determined as follows. The robust time domain template is assumed to take the form w(t)=A(t)cos{2.phi.(t)}. Since the instantaneous frequency f(t) is known to be equal to the derivative of the phase .phi.(t), the trajectory of a joint time-frequency representation of x(t) is used as an approximation of .phi.'(t).

  9. System and method for detection of dispersed broadband signals

    DOEpatents

    Qian, S.; Dunham, M.E.

    1999-06-08

    A system and method for detecting the presence of dispersed broadband signals in real time are disclosed. The present invention utilizes a bank of matched filters for detecting the received dispersed broadband signals. Each matched filter uses a respective robust time template that has been designed to approximate the dispersed broadband signals of interest, and each time template varies across a spectrum of possible dispersed broadband signal time templates. The received dispersed broadband signal x(t) is received by each of the matched filters, and if one or more matches occurs, then the received data is determined to have signal data of interest. This signal data can then be analyzed and/or transmitted to Earth for analysis, as desired. The system and method of the present invention will prove extremely useful in many fields, including satellite communications, plasma physics, and interstellar research. The varying time templates used in the bank of matched filters are determined as follows. The robust time domain template is assumed to take the form w(t)=A(t)cos[l brace]2[phi](t)[r brace]. Since the instantaneous frequency f(t) is known to be equal to the derivative of the phase [phi](t), the trajectory of a joint time-frequency representation of x(t) is used as an approximation of [phi][prime](t). 10 figs.

  10. Fluorescence quenching as an indirect detection method for nitrated explosives.

    PubMed

    Goodpaster, J V; McGuffin, V L

    2001-05-01

    A novel approach based on fluorescence quenching is presented for the analysis of nitrated explosives. Seventeen common explosives and their degradation products are shown to be potent quenchers of pyrene, having Stern-Volmer constants that generally increase with the degree of nitration. Aromatic explosives such as 2,4,6-trinitrotoluene (2,4,6-TNT) are more effective quenchers than aliphatic or nitramine explosives. In addition, nitroaromatic explosives are found to have unique interactions with pyrene that lead to a wavelength dependence of their Stern-Volmer constants. This phenomenon allows for their differentiation from other nitrated explosives. The fluorescence quenching method is then applied to the determination of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazine(HMX), 2,4,6-TNT, nitromethane, and ammonium nitrate in various commercial explosive samples. The samples are separated by capillary liquid chromatography with post-column addition of the pyrene solution and detection by laser-induced fluorescence. The indirect fluorescence quenching method shows increased sensitivity and selectivity over traditional UV-visible absorbance as well as the ability to detect a wider range of organic and inorganic nitrated compounds.

  11. Detecting early recovery of consciousness: a comparison of methods.

    PubMed

    Day, Kristin V; DiNapoli, Michael V; Whyte, John

    2017-04-07

    Early detection of the return of consciousness has important implications for prognosis and rehabilitation access. The aim of this study was to compare the Coma Recovery Scale-Revised (CRS-R) with individualised quantitative behavioural assessments (IQBA) to determine which method is capable of detecting command-following earlier and more consistently in persons with disorders of consciousness (DoC). Data from 27 patients with DoC, who underwent both assessments concurrently during inpatient rehabilitation, were retrospectively analysed. For each person, performance trajectories on the CRS-R auditory subscale item and IQBA dual command protocols were graphed together to identify earlier and more consistent evidence of consciousness; grouped data were analysed statistically. For 22 patients, IQBA more consistently documented consciousness than the CRS-R, whereas no patients showed the reverse pattern. For 14 of 20 analysable patients, IQBA provided earlier evidence of consciousness, for two patients CRS-R provided earlier evidence, and for four patients both methods provided initial evidence on the same day. These findings suggest that IQBA approaches can provide more consistent and earlier evidence of command-following than the comparable item on the CRS-R. Whether this advantage is due to the individualisation of IQBA or the greater volume of data gathered requires further research.

  12. Detection of hazardous cavities with combined geophysical methods

    NASA Astrophysics Data System (ADS)

    Hegymegi, Cs.; Nyari, Zs.; Pattantyus-Abraham, M.

    2003-04-01

    Unknown near-surface cavities often cause problems for municipal communities all over the world. This is the situation in Hungary in many towns and villages, too. Inhabitants and owners of real estates (houses, cottages, lands) are responsible for the safety and stability of their properties. The safety of public sites belongs to the local municipal community. Both (the owner and the community) are interested in preventing accidents. Near-surface cavities (unknown caves or earlier built and forgotten cellars) usually can be easily detected by surface geophysical methods. Traditional and recently developed measuring techniques in seismics, geoelectrics and georadar are suitable for economical investigation of hazardous, potentially collapsing cavities, prior to excavation and reinforcement. This poster will show some example for detection of cellars and caves being dangerous for civil population because of possible collapse under public sites (road, yard, playground, agricultural territory, etc.). The applied and presented methods are ground penetrating radar, seismic surface tomography and analysis of single traces, geoelectric 2D and 3D resistivity profiling. Technology and processing procedure will be presented.

  13. Artificial Intelligence Methods Applied to Parameter Detection of Atrial Fibrillation

    NASA Astrophysics Data System (ADS)

    Arotaritei, D.; Rotariu, C.

    2015-09-01

    In this paper we present a novel method to develop an atrial fibrillation (AF) based on statistical descriptors and hybrid neuro-fuzzy and crisp system. The inference of system produce rules of type if-then-else that care extracted to construct a binary decision system: normal of atrial fibrillation. We use TPR (Turning Point Ratio), SE (Shannon Entropy) and RMSSD (Root Mean Square of Successive Differences) along with a new descriptor, Teager- Kaiser energy, in order to improve the accuracy of detection. The descriptors are calculated over a sliding window that produce very large number of vectors (massive dataset) used by classifier. The length of window is a crisp descriptor meanwhile the rest of descriptors are interval-valued type. The parameters of hybrid system are adapted using Genetic Algorithm (GA) algorithm with fitness single objective target: highest values for sensibility and sensitivity. The rules are extracted and they are part of the decision system. The proposed method was tested using the Physionet MIT-BIH Atrial Fibrillation Database and the experimental results revealed a good accuracy of AF detection in terms of sensitivity and specificity (above 90%).

  14. Development of standard method performance requirements for biological threat agent detection methods.

    PubMed

    Coates, Scott G; Brunelle, Sharon L; Davenport, Matthew G

    2011-01-01

    Standards and third-party testing are necessary to demonstrate the performance and limitations of biological threat agent (biothreat) detection technologies to allow appropriate response actions by end-users and responders. In order to address this need, the Department of Homeland Security, Science and Technology Directorate has funded AOAC INTERNATIONAL to develop standards and perform conformity assessment. AOAC formed the Stakeholder Panel on Agent Detection Assays to develop consensus performance criteria (standard method performance requirements; SMPRs) for methods that detect biothreats. This paper documents the development of the first five biothreat SMPRs, including the voluntary consensus process, the components of an SMPR, the use of SMPRs in developing validation protocols, and a description of the development efforts and considerations for each of the current SMPRs.

  15. A Robust Shape Reconstruction Method for Facial Feature Point Detection

    PubMed Central

    Huang, Zhiqi

    2017-01-01

    Facial feature point detection has been receiving great research advances in recent years. Numerous methods have been developed and applied in practical face analysis systems. However, it is still a quite challenging task because of the large variability in expression and gestures and the existence of occlusions in real-world photo shoot. In this paper, we present a robust sparse reconstruction method for the face alignment problems. Instead of a direct regression between the feature space and the shape space, the concept of shape increment reconstruction is introduced. Moreover, a set of coupled overcomplete dictionaries termed the shape increment dictionary and the local appearance dictionary are learned in a regressive manner to select robust features and fit shape increments. Additionally, to make the learned model more generalized, we select the best matched parameter set through extensive validation tests. Experimental results on three public datasets demonstrate that the proposed method achieves a better robustness over the state-of-the-art methods. PMID:28316615

  16. Distribution of variables by method of outlier detection.

    PubMed

    Finch, W Holmes

    2012-01-01

    The presence of outliers can very problematic in data analysis, leading statisticians to develop a wide variety of methods for identifying them in both the univariate and multivariate contexts. In case of the latter, perhaps the most popular approach has been Mahalanobis distance, where large values suggest an observation that is unusual as compared to the center of the data. However, researchers have identified problems with the application of this metric such that its utility may be limited in some situations. As a consequence, other methods for detecting outlying observations have been developed and studied. However, a number of these approaches, while apparently robust and useful have not made their way into general practice in the social sciences. Thus, the goal of this study was to describe some of these methods and demonstrate them using a well known dataset from a popular multivariate textbook widely used in the social sciences. Results demonstrated that the methods do indeed result in datasets with very different distributional characteristics. These results are discussed in light of how they might be used by researchers and practitioners.

  17. New background correction method for liquid chromatography with diode array detection, infrared spectroscopic detection and Raman spectroscopic detection.

    PubMed

    Boelens, Hans F M; Dijkstra, Reyer J; Eilers, Paul H C; Fitzpatrick, Fiona; Westerhuis, Johan A

    2004-11-19

    A new method to eliminate the background spectrum (EBS) during analyte elution in column liquid chromatography (LC) coupled to spectroscopic techniques is proposed. This method takes into account the shape and also intensity differences of the background eluent spectrum. This allows the EBS method to make a better estimation of the background eluent spectrum during analyte elution. This is an advantage for quantification as well as for identification of analytes. The EBS method uses a two-step procedure. First, the baseline spectra are modeled using a limited number of principal components (PCs). Subsequently, an asymmetric least squares (asLS) regression method is applied using these principal components to correct the measured spectra during elution for the background contribution. The asymmetric least squares regression needs one parameter, the asymmetry factor p. This asymmetry factor determines relative weight of positive and negative residuals. Simulations are performed to test the EBS method in well-defined situations. The effect of spectral noise on the performance and the sensitivity of the EBS method for the value of the asymmetry factorp is tested. Two applications of the EBS method are discussed. In the first application, the goal is to extract the analyte spectrum from an LC-Raman analysis. In this case, the EBS method facilitates easy identification of unknown analytes using spectral libraries. In a second application, the EBS method is used for baseline correction in LC-diode array detection (DAD) analysis of polymeric standards during a gradient elution separation. It is shown that the EBS method yields a good baseline correction, without the need to perform a blank chromatographic run.

  18. Improved slicing method for GOSAT cloud detection using TIR spectra

    NASA Astrophysics Data System (ADS)

    Someya, Y.; Imasu, R.; Shiomi, K.; Saitoh, N.; Ota, Y.

    2015-12-01

    Greenhouse gas observing SATellite (GOSAT) is a polar orbiting satellite for greenhouse gas observations and the main sensor, TANSO-FTS, has three near-infrared bands and a thermal infrared (TIR) band which covers a wide spectral region of 5.56 - 14.3 mm with resolution of 0.2 cm-1. The algorithm used in this study was based on a cirrus detection technique called CO2 slicing method, modified as described below. The weighting functions which represent sensitivity profiles were calculated at each channel in the TIR band of GOSAT. The channels were reconstructed as sets of several spectral channels for each height level based on the peak heights of the weighting functions. Subsequently, the channel combinations were optimized based on simulation studies for several temperature profile patterns for each latitude and temperature at 500 hPa. The observed data in 2010 were analyzed using these optimized channels. Global cloud amounts and their seasonal variations were validated using Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) data. Results show some differences of cloud amounts and heights between GOSAT and CALIPSO, which might be caused by surface temperature biases, the inverse layer, the difference of sensitivity of sensors, and marine stratocumulus clouds. However, the characteristics of horizontal distributions derived using the slicing method were generally agreed with those obtained from CALIPSO and reported in previous researches. In addition, comparison of cloud top height using collocated data showed good agreement and clouds with optical thickness less than 0.1 are detectable using this method.

  19. NEW COMPLETENESS METHODS FOR ESTIMATING EXOPLANET DISCOVERIES BY DIRECT DETECTION

    SciTech Connect

    Brown, Robert A.; Soummer, Remi

    2010-05-20

    We report on new methods for evaluating realistic observing programs that search stars for planets by direct imaging, where observations are selected from an optimized star list and stars can be observed multiple times. We show how these methods bring critical insight into the design of the mission and its instruments. These methods provide an estimate of the outcome of the observing program: the probability distribution of discoveries (detection and/or characterization) and an estimate of the occurrence rate of planets ({eta}). We show that these parameters can be accurately estimated from a single mission simulation, without the need for a complete Monte Carlo mission simulation, and we prove the accuracy of this new approach. Our methods provide tools to define a mission for a particular science goal; for example, a mission can be defined by the expected number of discoveries and its confidence level. We detail how an optimized star list can be built and how successive observations can be selected. Our approach also provides other critical mission attributes, such as the number of stars expected to be searched and the probability of zero discoveries. Because these attributes depend strongly on the mission scale (telescope diameter, observing capabilities and constraints, mission lifetime, etc.), our methods are directly applicable to the design of such future missions and provide guidance to the mission and instrument design based on scientific performance. We illustrate our new methods with practical calculations and exploratory design reference missions for the James Webb Space Telescope (JWST) operating with a distant starshade to reduce scattered and diffracted starlight on the focal plane. We estimate that five habitable Earth-mass planets would be discovered and characterized with spectroscopy, with a probability of zero discoveries of 0.004, assuming a small fraction of JWST observing time (7%), {eta} = 0.3, and 70 observing visits, limited by starshade

  20. A Distributed Signature Detection Method for Detecting Intrusions in Sensor Systems

    PubMed Central

    Kim, Ilkyu; Oh, Doohwan; Yoon, Myung Kuk; Yi, Kyueun; Ro, Won Woo

    2013-01-01

    Sensor nodes in wireless sensor networks are easily exposed to open and unprotected regions. A security solution is strongly recommended to prevent networks against malicious attacks. Although many intrusion detection systems have been developed, most systems are difficult to implement for the sensor nodes owing to limited computation resources. To address this problem, we develop a novel distributed network intrusion detection system based on the Wu–Manber algorithm. In the proposed system, the algorithm is divided into two steps; the first step is dedicated to a sensor node, and the second step is assigned to a base station. In addition, the first step is modified to achieve efficient performance under limited computation resources. We conduct evaluations with random string sets and actual intrusion signatures to show the performance improvement of the proposed method. The proposed method achieves a speedup factor of 25.96 and reduces 43.94% of packet transmissions to the base station compared with the previously proposed method. The system achieves efficient utilization of the sensor nodes and provides a structural basis of cooperative systems among the sensors. PMID:23529146