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Sample records for antigen retrieval methods

  1. Antigen Retrieval Immunohistochemistry

    PubMed Central

    Shi, Shan-Rong; Shi, Yan; Taylor, Clive R.

    2011-01-01

    As a review for the 20th anniversary of publishing the antigen retrieval (AR) technique in this journal, the authors intend briefly to summarize developments in AR-immunohistochemistry (IHC)–based research and diagnostics, with particular emphasis on current challenges and future research directions. Over the past 20 years, the efforts of many different investigators have coalesced in extending the AR approach to all areas of anatomic pathology diagnosis and research and further have led to AR-based protein extraction techniques and tissue-based proteomics. As a result, formalin-fixed paraffin-embedded (FFPE) archival tissue collections are now seen as a literal treasure of materials for clinical and translational research to an extent unimaginable just two decades ago. Further research in AR-IHC is likely to focus on tissue proteomics, developing a more efficient protocol for protein extraction from FFPE tissue based on the AR principle, and combining the proteomics approach with AR-IHC to establish a practical, sophisticated platform for identifying and using biomarkers in personalized medicine. PMID:21339172

  2. Antigen retrieval techniques: current perspectives.

    PubMed

    Shi, S R; Cote, R J; Taylor, C R

    2001-08-01

    Development of the antigen retrieval (AR) technique, a simple method of boiling archival paraffin-embedded tissue sections in water to enhance the signal of immunohistochemistry (IHC), was the fruit of pioneering efforts guided by the philosophy of rendering IHC applicable to routine formalin-fixed, paraffin-embedded tissues for wide application of IHC in research and clinical pathology. On the basis of thousands of articles and many reviews, a book has recently been published that summarizes basic principles for practice and further development of the AR technique. Major topics with respect to several critical issues, such as the definition, application, technical principles, and further studies of the AR technique, are highlighted in this article. In particular, a further application of the heat-induced retrieval approach for sufficient extraction of nucleic acids in addition to proteins, and standardization of routine IHC based on the AR technique in terms of a test battery approach, are also addressed. Furthermore, understanding the mechanism of the AR technique may shed light on facilitating the development of molecular morphology.

  3. A microwave antigen retrieval method using two heating steps for enhanced immunostaining on aldehyde-fixed paraffin-embedded tissue sections.

    PubMed

    Gu, Ling; Cong, Jing; Zhang, Jie; Tian, Ying-Ying; Zhai, Xiao-Yue

    2016-06-01

    Antigen retrieval is an immunohistochemical procedure that results in better exposure of target antigens in aldehyde-fixed, paraffin-embedded tissue sections to antibodies. However, the commercially recommended or conventional protocols for antigen retrieval do not always succeed in expressing the target antigen. Here, an improved method was developed for antigen retrieval from aldehyde-fixed, paraffin-embedded histological sections. Proliferating cell nuclear antigen (PCNA), tight junction proteins Claudin-2 and Claudin-7, and water channel aquaporins in kidney tissue were selected as test antigens. Typically, PCNA and Claudin-2 and Claudin-7 show negative, weak, or nonspecific immunoreactions with conventional antigen retrieval methods using microwave heating. In the present study, microwave heating was performed twice with an interval of 30 min between the two steps to allow the buffer solution to cool. Sodium citrate buffer (10 mM sodium citrate, pH 6.0) was used for PCNA, and Tris-EDTA buffer (10 mM Tris, 1 mM EDTA, pH 9.0) was used for the Claudins. Compared with conventionally prepared tissues, the tissues exhibited both enhanced and specific immunostaining, and well-preserved morphology. In conclusion, the conventional protocol could be supplemented with a second microwave heating step to improve the expression of antigens that do not respond well to the conventional method. PMID:27002723

  4. Formaldehyde scavengers function as novel antigen retrieval agents.

    PubMed

    Vollert, Craig T; Moree, Wilna J; Gregory, Steven; Bark, Steven J; Eriksen, Jason L

    2015-11-27

    Antigen retrieval agents improve the detection of formaldehyde-fixed proteins, but how they work is not well understood. We demonstrate that formaldehyde scavenging represents a key characteristic associated with effective antigen retrieval; under controlled temperature and pH conditions, scavenging improves the typical antigen retrieval process through reversal of formaldehyde-protein adduct formation. This approach provides a rational framework for the identification and development of more effective antigen retrieval agents.

  5. Formaldehyde scavengers function as novel antigen retrieval agents

    PubMed Central

    Vollert, Craig T.; Moree, Wilna J.; Gregory, Steven; Bark, Steven J.; Eriksen, Jason L.

    2015-01-01

    Antigen retrieval agents improve the detection of formaldehyde-fixed proteins, but how they work is not well understood. We demonstrate that formaldehyde scavenging represents a key characteristic associated with effective antigen retrieval; under controlled temperature and pH conditions, scavenging improves the typical antigen retrieval process through reversal of formaldehyde-protein adduct formation. This approach provides a rational framework for the identification and development of more effective antigen retrieval agents. PMID:26612041

  6. A New Antigen Retrieval Technique for Human Brain Tissue

    PubMed Central

    Byne, William; Haroutunian, Vahram; García-Villanueva, Mercedes; Rábano, Alberto; García-Amado, María; Prensa, Lucía; Giménez-Amaya, José Manuel

    2008-01-01

    Immunohistochemical staining of tissues is a powerful tool used to delineate the presence or absence of an antigen. During the last 30 years, antigen visualization in human brain tissue has been significantly limited by the masking effect of fixatives. In the present study, we have used a new method for antigen retrieval in formalin-fixed human brain tissue and examined the effectiveness of this protocol to reveal masked antigens in tissues with both short and long formalin fixation times. This new method, which is based on the use of citraconic acid, has not been previously utilized in brain tissue although it has been employed in various other tissues such as tonsil, ovary, skin, lymph node, stomach, breast, colon, lung and thymus. Thus, we reported here a novel method to carry out immunohistochemical studies in free-floating human brain sections. Since fixation of brain tissue specimens in formaldehyde is a commonly method used in brain banks, this new antigen retrieval method could facilitate immunohistochemical studies of brains with prolonged formalin fixation times. PMID:18852880

  7. Instability of induction cooker (electromagnetic stove) antigen retrieval in immunohistochemistry.

    PubMed

    Ding, Wei; Zheng, Xiang-Yi

    2012-03-01

    An induction cooker is a modern electric cooker that takes electromagnetic induction principle to heat. As it has high efficiency, no open flame, and is safe and convenient, more and more laboratories use it as an antigen retrieval heating tool in immunohistochemistry. We found that there was still some instability with the induction cooker, because with certain antigens the power change influenced the results of immunohistochemistry staining, showing weaker staining intensity or decreased number of positive cells, but which were not entirely negative. For some antigens, it had no influence on results. The instability of this heating tool for antigen retrieval was caused partly by negligent operators, and which may influence the experimental results and the pathologic diagnosis.

  8. Immunohistochemical detection of disease-associated prion protein in the intestine of cattle naturally affected with bovine spongiform encephalopathy by using an alkaline-based chemical antigen retrieval method.

    PubMed

    Okada, Hiroyuki; Iwamaru, Yoshihumi; Imamura, Morikazu; Masujin, Kentaro; Yokoyama, Takashi; Mohri, Shirou

    2010-11-01

    An alkaline-based chemical antigen retrieval pretreatment step was used to enhance immunolabeling of disease-associated prion protein (PrP(Sc)) in formalin-fixed and paraffin-embedded tissue sections from cattle naturally affected with bovine spongiform encephalopathy (BSE). The modified chemical method used in this study amplified the PrP(Sc) signal by unmasking PrP(Sc) compared with the normal cellular prion protein. In addition, this method reduced nonspecific background immunolabeling that resulted from the destruction of the residual normal cellular form of prion protein, and reduced the treatment time compared with the usual autoclave pretreatment step. Immunolabeled PrP(Sc) was thereby clearly detected in the myenteric plexus of the ileum in naturally occurring BSE cattle.

  9. Notes on the application of microwaves for antigen retrieval in paraffin and plastic tissue sections.

    PubMed

    Suurmeijer, A J; Boon, M E

    1993-01-01

    In formalin-fixed, paraffin-embedded tissue enhanced or de novo immunostaining can be obtained by microwave boiling of sections in a metal salt or buffer solution. In this paper this new technique is reviewed and important factors influencing final results are discussed. Microwave antigen retrieval can also be applied for immunohistochemistry on plastic GMA sections. Here the action of the microwave method is probably mainly due to breaking the bonds between GMA and proteins prohibiting immunostaining. The microwave methods do not require trypsin treatment.

  10. Post-embedding Mammalian Tissue for Immunoelectron Microscopy: A Standardized Procedure Based on Heat-Induced Antigen Retrieval.

    PubMed

    Yamashita, Shuji

    2016-01-01

    We describe a standardized method of fixation, antigen retrieval, and image contrasting for post-embedding immunoelectron microscopy. Tissues are fixed with formaldehyde solutions containing Ca(2+) and Mg(2+) ions at pH 7.4 and then at pH 8.5. After dehydration with dimethylformamide, the specimens are embedded in LR-White resin. For antigen retrieval, ultrathin sections are heated in 0.5 M Tris-HCl, pH 9.0, for 1-2 h at 95 °C. After immunogold labeling, the sections are treated with a mixture of tannic acid and glutaraldehyde, with OsO4 solution, and then double-stained with uranyl acetate and lead citrate. The standardized method yields strong and reproducible immunoreactions for many antigens showing excellent image contrast without destruction of fine structures. PMID:27515088

  11. Robust keyword retrieval method for OCRed text

    NASA Astrophysics Data System (ADS)

    Fujii, Yusaku; Takebe, Hiroaki; Tanaka, Hiroshi; Hotta, Yoshinobu

    2011-01-01

    Document management systems have become important because of the growing popularity of electronic filing of documents and scanning of books, magazines, manuals, etc., through a scanner or a digital camera, for storage or reading on a PC or an electronic book. Text information acquired by optical character recognition (OCR) is usually added to the electronic documents for document retrieval. Since texts generated by OCR generally include character recognition errors, robust retrieval methods have been introduced to overcome this problem. In this paper, we propose a retrieval method that is robust against both character segmentation and recognition errors. In the proposed method, the insertion of noise characters and dropping of characters in the keyword retrieval enables robustness against character segmentation errors, and character substitution in the keyword of the recognition candidate for each character in OCR or any other character enables robustness against character recognition errors. The recall rate of the proposed method was 15% higher than that of the conventional method. However, the precision rate was 64% lower.

  12. Evolutionary Computing Methods for Spectral Retrieval

    NASA Technical Reports Server (NTRS)

    Terrile, Richard; Fink, Wolfgang; Huntsberger, Terrance; Lee, Seugwon; Tisdale, Edwin; VonAllmen, Paul; Tinetti, Geivanna

    2009-01-01

    A methodology for processing spectral images to retrieve information on underlying physical, chemical, and/or biological phenomena is based on evolutionary and related computational methods implemented in software. In a typical case, the solution (the information that one seeks to retrieve) consists of parameters of a mathematical model that represents one or more of the phenomena of interest. The methodology was developed for the initial purpose of retrieving the desired information from spectral image data acquired by remote-sensing instruments aimed at planets (including the Earth). Examples of information desired in such applications include trace gas concentrations, temperature profiles, surface types, day/night fractions, cloud/aerosol fractions, seasons, and viewing angles. The methodology is also potentially useful for retrieving information on chemical and/or biological hazards in terrestrial settings. In this methodology, one utilizes an iterative process that minimizes a fitness function indicative of the degree of dissimilarity between observed and synthetic spectral and angular data. The evolutionary computing methods that lie at the heart of this process yield a population of solutions (sets of the desired parameters) within an accuracy represented by a fitness-function value specified by the user. The evolutionary computing methods (ECM) used in this methodology are Genetic Algorithms and Simulated Annealing, both of which are well-established optimization techniques and have also been described in previous NASA Tech Briefs articles. These are embedded in a conceptual framework, represented in the architecture of the implementing software, that enables automatic retrieval of spectral and angular data and analysis of the retrieved solutions for uniqueness.

  13. Use of pH 9.5 Tris-HCl buffer containing 5% urea for antigen retrieval immunohistochemistry.

    PubMed

    Shi, S R; Cote, R J; Young, L; Imam, S A; Taylor, C R

    1996-07-01

    Successful antigen retrieval (AR) immunohistochemistry is dependent on the temperature, heating time, and pH value of the AR solutions. There is no single standardized AR solution, however, that is suitable for all antibodies "routinely" used in surgical pathology for immunostaining archival tissue sections. We tested a variety of AR solutions varying in pH value, chemical composition, and molarity. Based upon preliminary results, we compared three AR solutions: 0.1 M Tris-HCl buffer, pH 9.5, containing 5% urea, 0.1 M Tris-HCl buffer pH 9.5 without urea, and citrate buffer, pH 6.0. Each AR solution was tested with a panel of 34 antibodies using microwave heating for antigen retrieval. The heating conditions were standardized at 10 min and an automated stainer was used to standardize the immunostaining method. The Tris-HCl containing urea was superior to pH 6.0 citrate buffer for 22 antibodies. In 12 cases, Tris-HCl with urea was also superior to Tris-HCl alone. In 12 cases, the intensity was similar for all three retrieval solutions. The staining obtained with Tris-HCl with urea was equal to or better than with pH 6.0 citrate buffer in all cases. The Tris-HCl with urea solution is satisfactory for AR of most antibodies employed in routine surgical pathology.

  14. SDS-PAGE/immunoblot detection of Abeta multimers in human cortical tissue homogenates using antigen-epitope retrieval.

    PubMed

    Rosen, Rebecca F; Tomidokoro, Yasushi; Ghiso, Jorge A; Walker, Lary C

    2010-01-01

    The anomalous folding and polymerization of the beta-amyloid (Abeta) peptide is thought to initiate the neurodegenerative cascade in Alzheimer's disease pathogenesis(1). Abeta is predominantly a 40- or 42-amino acid peptide that is prone to self-aggregation into beta-sheet-rich amyloid fibrils that are found in the cores of cerebral senile plaques in Alzheimer's disease. Increasing evidence suggests that low molecular weight, soluble Abeta multimers are more toxic than fibrillar Abeta amyloid(2). The identification and quantification of low- and high-molecular weight multimeric Abeta species in brain tissue is an essential objective in Alzheimer's disease research, and the methods employed also can be applied to the identification and characterization of toxic multimers in other proteopathies(3). Naturally occurring Abeta multimers can be detected by SDS-polyacrylamide gel electrophoresis followed by immunoblotting with Abeta-specific antibodies. However, the separation and detection of multimeric Abeta requires the use of highly concentrated cortical homogenates and antigen retrieval in small pore-size nitrocellulose membranes. Here we describe a technique for the preparation of clarified human cortical homogenates, separation of proteins by SDS-PAGE, and antigen-epitope retrieval/Western blotting with antibody 6E10 to the N-terminal region of the Abeta peptide. Using this protocol, we consistently detect Abeta monomers, dimers, trimers, tetramers, and higher molecular weight multimers in cortical tissue from humans with Alzheimer's pathology. PMID:20418805

  15. p53 gene product expression in resected non-small cell carcinoma of the lung, with studies of concurrent cytological preparations and microwave antigen retrieval.

    PubMed Central

    Binks, S; Clelland, C A; Ronan, J; Bell, J

    1997-01-01

    AIM: To document the frequency and extent of p53 gene product expression in paraffin sections of resected non-small cell carcinoma of the lung and in cytological preparations of the same tumours; to determine the effect of microwave antigen retrieval on antigen detection. METHODS: Representative paraffin sections of 50 non-small cell carcinomas were stained with an antibody to p53 gene product (DO-7) both with and without prior microwave antigen retrieval. Cytoblocks and cell smears obtained from 19 cases were similarly stained. RESULTS: Using a histochemical scoring system (0-300) which takes into account staining intensity and extent, 78% (n = 39) of microwave pretreated paraffin sections and 52% (n = 26) of non-pretreated sections scored between 5 and 300; p = 0.001; 56% (n = 28) of microwave pretreated sections and only 2% (n = 1) of non-pretreated sections scored between 100 and 300 (p = 0.0001); 75% of direct smears of tumours and 80% of cytoblocks stained similarly to the paraffin sections of the resected specimens. No smears or cytoblocks stained positively when the sections of the resected specimen were negative. CONCLUSIONS: As up to 78% of non-small cell lung carcinomas overexpress p53 gene product, this may prove to be a valuable diagnostic method in biopsy or cytological material when the morphological diagnosis is uncertain. Microwave antigen retrieval is effective on formalin fixed tissue. Images PMID:9215149

  16. Analysis of formalin-fixed, paraffin-embedded (FFPE) tissue via proteomic techniques and misconceptions of antigen retrieval.

    PubMed

    O'Rourke, Matthew B; Padula, Matthew P

    2016-01-01

    Since emerging in the late 19(th) century, formaldehyde fixation has become a standard method for preservation of tissues from clinical samples. The advantage of formaldehyde fixation is that fixed tissues can be stored at room temperature for decades without concern for degradation. This has led to the generation of huge tissue banks containing thousands of clinically significant samples. Here we review techniques for proteomic analysis of formalin-fixed, paraffin-embedded (FFPE) tissue samples with a specific focus on the methods used to extract and break formaldehyde crosslinks. We also discuss an error-of-interpretation associated with the technique known as "antigen retrieval." We have discovered that this term has been mistakenly applied to two disparate molecular techniques; therefore, we argue that a terminology change is needed to ensure accurate reporting of experimental results. Finally, we suggest that more investigation is required to fully understand the process of formaldehyde fixation and its subsequent reversal. PMID:27177815

  17. Comparative exoplanetology with consistent retrieval methods

    NASA Astrophysics Data System (ADS)

    Barstow, Joanna Katy; Aigrain, Suzanne; Irwin, Patrick Gerard Joseph; Sing, David

    2016-10-01

    The number of hot Jupiters with broad wavelength spectroscopic data has finally become large enough to make comparative planetology a reasonable proposition. New results presented by Sing et al. (2016) showcase ten hot Jupiters with spectra from the Hubble Space Telescope and photometry from Spitzer, providing insights into the presence of clouds and hazes.Spectral retrieval methods allow interpretation of exoplanet spectra using simple models, with minimal prior assumptions. This is particularly useful for exotic exoplanets, for which we may not yet fully understand the physical processes responsible for their atmospheric characteristics. Consistent spectral retrieval of a range of exoplanets can allow robust comparisons of their derived atmospheric properties.I will present a retrieval analysis using the NEMESIS code (Irwin et al. 2008) of the ten hot Jupiter spectra presented by Sing et al. (2016). The only distinctive aspects of the model for each planet are the mass and radius, and the temperature range explored. All other a priori model parameters are common to all ten objects. We test a range of cloud and haze scenarios, which include: Rayleigh-dominated and grey clouds; different cloud top pressures; and both vertically extended and vertically confined clouds.All ten planets, with the exception of WASP-39b, can be well represented by models with at least some haze or cloud. Our analysis of cloud properties has uncovered trends in cloud top pressure, vertical extent and particle size with planet equilibrium temperature. Taken together, we suggest that these trends indicate condensation and sedimentation of at least two different cloud species across planets of different temperatures, with condensates forming higher up in hotter atmospheres and moving progressively further down in cooler planets.Sing, D. et al. (2016), Nature, 529, 59Irwin, P. G. J. et al. (2008), JQSRT, 109, 1136

  18. Methods of Cost Reduction in Information Retrieval.

    ERIC Educational Resources Information Center

    Wilmoth, James Noel

    Cost effectiveness of the QUERY program for searching the Educational Resources Information Center (ERIC) data base has been an important issue at Auburn University. At least two broad categories of costs are associated with information retrieval from a data base such as ERIC: fixed costs or overhead and data base associated costs. The concern at…

  19. A diagram retrieval method with multi-label learning

    NASA Astrophysics Data System (ADS)

    Fu, Songping; Lu, Xiaoqing; Liu, Lu; Qu, Jingwei; Tang, Zhi

    2015-01-01

    In recent years, the retrieval of plane geometry figures (PGFs) has attracted increasing attention in the fields of mathematics education and computer science. However, the high cost of matching complex PGF features leads to the low efficiency of most retrieval systems. This paper proposes an indirect classification method based on multi-label learning, which improves retrieval efficiency by reducing the scope of compare operation from the whole database to small candidate groups. Label correlations among PGFs are taken into account for the multi-label classification task. The primitive feature selection for multi-label learning and the feature description of visual geometric elements are conducted individually to match similar PGFs. The experiment results show the competitive performance of the proposed method compared with existing PGF retrieval methods in terms of both time consumption and retrieval quality.

  20. Using optimal estimation method for upper atmospheric Lidar temperature retrieval

    NASA Astrophysics Data System (ADS)

    Zou, Rongshi; Pan, Weilin; Qiao, Shuai

    2016-07-01

    Conventional ground based Rayleigh lidar temperature retrieval use integrate technique, which has limitations that necessitate abandoning temperatures retrieved at the greatest heights due to the assumption of a seeding value required to initialize the integration at the highest altitude. Here we suggests the use of a method that can incorporate information from various sources to improve the quality of the retrieval result. This approach inverts lidar equation via optimal estimation method(OEM) based on Bayesian theory together with Gaussian statistical model. It presents many advantages over the conventional ones: 1) the possibility of incorporating information from multiple heterogeneous sources; 2) provides diagnostic information about retrieval qualities; 3) ability of determining vertical resolution and maximum height to which the retrieval is mostly independent of the a priori profile. This paper compares one-hour temperature profiles retrieved using conventional and optimal estimation methods at Golmud, Qinghai province, China. Results show that OEM results show a better agreement with SABER profile compared with conventional one, in some region it is much lower than SABER profile, which is a very different results compared with previous studies, further studies are needed to explain this phenomenon. The success of applying OEM on temperature retrieval is a validation for using as retrieval framework in large synthetic observation systems including various active remote sensing instruments by incorporating all available measurement information into the model and analyze groups of measurements simultaneously to improve the results.

  1. Methods for determining regularization for atmospheric retrieval problems

    NASA Astrophysics Data System (ADS)

    Steck, Tilman

    2002-03-01

    The atmosphere of Earth has already been investigated by several spaceborne instruments, and several further instruments will be launched, e.g., NASA's Earth Observing System Aura platform and the European Space Agency's Environmental Satellite. To stabilize the results in atmospheric retrievals, constraints are used in the iteration process. Therefore hard constraints (discretization of the retrieval grid) and soft constraints (regularization operators) are included in the retrieval. Tikhonov regularization is often used as a soft constraint. In this study, different types of Tikhonov operator were compared, and several new methods were developed to determine the optimal strength of the constraint operationally. The resulting regularization parameters were applied successfully to an ozone retrieval from simulated nadir sounding spectra like those expected to be measured by the Tropospheric Emission Spectrometer, which is part of the Aura platform. Retrievals were characterized by means of estimated error, averaging kernel, vertical resolution, and degrees of freedom.

  2. Energy filtering transmission electron microscopy immunocytochemistry and antigen retrieval of surface layer proteins from Tannerella forsythensis using microwave or autoclave heating with citraconic anhydride.

    PubMed

    Moriguchi, K; Mitamura, Y; Iwami, J; Hasegawa, Y; Higuchi, N; Murakami, Y; Maeda, H; Yoshimura, F; Nakamura, H; Ohno, N

    2012-11-01

    Tannerella forsythensis (Bacteroides forsythus), an anaerobic Gram-negative species of bacteria that plays a role in the progression of periodontal disease, has a unique bacterial protein profile. It is characterized by two unique protein bands with molecular weights of more than 200 kDa. It also is known to have a typical surface layer (S-layer) consisting of regularly arrayed subunits outside the outer membrane. We examined the relationship between high molecular weight proteins and the S-layer using electron microscopic immunolabeling with chemical fixation and an antigen retrieval procedure consisting of heating in a microwave oven or autoclave with citraconic anhydride. Immunogold particles were localized clearly at the outermost cell surface. We also used energy-filtering transmission electron microscopy (EFTEM) to visualize 3, 3'-diaminobenzidine tetrahydrochloride (DAB) reaction products after microwave antigen retrieval with 1% citraconic anhydride. The three-window method for electron spectroscopic images (ESI) of nitrogen by the EFTEM reflected the presence of moieties demonstrated by the DAB reaction with horseradish peroxidase (HRP)-conjugated secondary antibodies instead of immunogold particles. The mapping patterns of net nitrogen were restricted to the outermost cell surface.

  3. An improved method for Doppler wind and thermodynamic retrievals

    NASA Astrophysics Data System (ADS)

    Shun, Liu; Chongjian, Qiu; Qin, Xu; Pengfei, Zhang; Jidong, Gao; Aimei, Shao

    2005-01-01

    A variational method is developed to retrieve winds in the first step and then thermodynamic fields in the second step from Doppler radar observations. In the first step, wind fields are retrieved at two time levels: the beginning and ending times of the data assimilation period, simultaneously from two successive volume scans by using the weak form constraints provided by the mass continuity and vorticity equations. As the retrieved wind fields are expressed by Legendre polynomial expansions at the beginning and ending times, the time tendency term in the vorticity equation can be conveniently formulated, and the retrieved winds can be compared with the radar observed radial winds in the cost function at the precise time and position of each radar beam. In the second step, the perturbation pressure and temperature fields at the middle time are then derived from the retrieved wind fields and the velocity time tendency by using the weak form constraints provided by the three momentum equations. The merits of the new method are demonstrated by numerical experiments with simulated radar observations and compared with the traditional least squares methods which consider neither the precise observation times and positions nor the velocity time tendency. The new method is also applied to real radar data for a heavy rainfall event during the 2001 Meiyu season in China.

  4. Efficient Methods to Assimilate Satellite Retrievals Based on Information Content. Part 2; Suboptimal Retrieval Assimilation

    NASA Technical Reports Server (NTRS)

    Joiner, J.; Dee, D. P.

    1998-01-01

    One of the outstanding problems in data assimilation has been and continues to be how best to utilize satellite data while balancing the tradeoff between accuracy and computational cost. A number of weather prediction centers have recently achieved remarkable success in improving their forecast skill by changing the method by which satellite data are assimilated into the forecast model from the traditional approach of assimilating retrievals to the direct assimilation of radiances in a variational framework. The operational implementation of such a substantial change in methodology involves a great number of technical details, e.g., pertaining to quality control procedures, systematic error correction techniques, and tuning of the statistical parameters in the analysis algorithm. Although there are clear theoretical advantages to the direct radiance assimilation approach, it is not obvious at all to what extent the improvements that have been obtained so far can be attributed to the change in methodology, or to various technical aspects of the implementation. The issue is of interest because retrieval assimilation retains many practical and logistical advantages which may become even more significant in the near future when increasingly high-volume data sources become available. The central question we address here is: how much improvement can we expect from assimilating radiances rather than retrievals, all other things being equal? We compare the two approaches in a simplified one-dimensional theoretical framework, in which problems related to quality control and systematic error correction are conveniently absent. By assuming a perfect radiative transfer model and perfect knowledge of radiance and background error covariances, we are able to formulate a nonlinear local error analysis for each assimilation method. Direct radiance assimilation is optimal in this idealized context, while the traditional method of assimilating retrievals is suboptimal because it

  5. Retrieval practice can eliminate list method directed forgetting.

    PubMed

    Abel, Magdalena; Bäuml, Karl-Heinz T

    2016-01-01

    It has recently been shown that retrieval practice can reduce memories' susceptibility to interference, like retroactive and proactive interference. In this study, we therefore examined whether retrieval practice can also reduce list method directed forgetting, a form of intentional forgetting that presupposes interference. In each of two experiments, subjects successively studied two lists of items. After studying each single list, subjects restudied the list items to enhance learning, or they were asked to recall the items. Following restudy or retrieval practice of list 1 items, subjects were cued to either forget the list or remember it for an upcoming final test. Experiment 1 employed a free-recall and Experiment 1 a cued-recall procedure on the final memory test. In both experiments, directed forgetting was present in the restudy condition but was absent in the retrieval-practice condition, indicating that retrieval practice can reduce or even eliminate this form of forgetting. The results are consistent with the view that retrieval practice enhances list segregation processes. Such processes may reduce interference between lists and thus reduce directed forgetting. PMID:26286882

  6. Retrieval practice can eliminate list method directed forgetting.

    PubMed

    Abel, Magdalena; Bäuml, Karl-Heinz T

    2016-01-01

    It has recently been shown that retrieval practice can reduce memories' susceptibility to interference, like retroactive and proactive interference. In this study, we therefore examined whether retrieval practice can also reduce list method directed forgetting, a form of intentional forgetting that presupposes interference. In each of two experiments, subjects successively studied two lists of items. After studying each single list, subjects restudied the list items to enhance learning, or they were asked to recall the items. Following restudy or retrieval practice of list 1 items, subjects were cued to either forget the list or remember it for an upcoming final test. Experiment 1 employed a free-recall and Experiment 1 a cued-recall procedure on the final memory test. In both experiments, directed forgetting was present in the restudy condition but was absent in the retrieval-practice condition, indicating that retrieval practice can reduce or even eliminate this form of forgetting. The results are consistent with the view that retrieval practice enhances list segregation processes. Such processes may reduce interference between lists and thus reduce directed forgetting.

  7. Analysis on wind retrieval methods for Rayleigh Doppler lidar

    NASA Astrophysics Data System (ADS)

    Han, Yuli; Dou, Xiankang; Sun, Dongsong; Xia, Haiyun; Shu, Zhifeng

    2014-06-01

    A modification method is described for Rayleigh Doppler lidar wind retrieval. Compared to the double-edge theory of Korb et al. [Appl. Opt., 38, 432 (1999)] and the retrieval algorithm of Chanin et al. [Geophys. Res. Lett., 16, 1273 (1989)], it has a greater sensitivity. The signal-to-noise ratio of the energy monitor channel is involved in error estimation. When the splitting ratio of the two signal channels is 1.2, which usually happened during wind detection, it will improve the measurement accuracy by about 1% at 30 km altitude for a Doppler shift of 250 MHz (44 m/s). Stabilities of retrieval methods, i.e., errors caused by the spectrum width deviation including laser pulse, Rayleigh backscatter, and filter transmission curve are first discussed. The proposed method increases the resultant precision by about 15% at 30-km altitude assuming an 8-MHz deviation in full width at half maximum of the Fabry-Perot interferometer.

  8. Proliferating cell nuclear antigen immunohistochemistry using monoclonal antibody 19A2 and a new antigen retrieval technique has prognostic impact in archival paraffin-embedded node-negative breast cancer.

    PubMed

    Siitonen, S M; Kallioniemi, O P; Isola, J J

    1993-04-01

    We evaluated whether proliferating cell nuclear antigen (PCNA) immunohistochemistry with antigen retrieval could be used as a measure of cell proliferation in archival, formalin-fixed, paraffin-embedded tissues and whether the staining results have long-term prognostic significance in axillary node-negative breast cancer. Primary tumor samples obtained from 109 axillary-node-negative breast cancer cases were used for the study. The best staining results were obtained with the 19A2 antibody after microwave heating in a solution of saturated lead thiocyanate. Using this method, there was a significant correlation (linear regression, r = 0.580, P < 0.001) between the proportion of PCNA19A2-positive carcinoma cells (PCNA19A2 score) and DNA flow cytometric S phase fraction. A high PCNA19A2 score was associated with high mitotic count, DNA aneuploidy, and absence of estrogen receptors. Axillary-node-negative patients with a high PCNA19A2 score (cut-point 8%) had significantly worse prognosis than those with a low PCNA19A2 score (P = 0.008). According to a Cox multivariate analysis, PCNA19A2 score had independent prognostic value but only if S phase fraction was excluded from the analysis. In our study, the PCNAPC10 score correlated weakly only with primary tumor size (analysis of variance) and prognosis (5-year univariate survival analysis), but the significance of these findings needs further evaluation. In conclusion, PCNA immunohistochemistry with the 19A2 antibody after an appropriate antigen retrieval treatment may offer a useful alternative to DNA flow cytometry for the analysis of cell proliferation activity from formalin-fixed, paraffin-embedded breast carcinomas.

  9. Antigen retrieval using pH 3.5 glycine-HCl buffer or urea solution for immunohistochemical localization of Ki-67.

    PubMed

    Shi, S R; Chaiwun, B; Young, L; Imam, A; Cote, R J; Taylor, C R

    1994-07-01

    A new antibody (MIB-1) has been described, permitting the demonstration of Ki-67 proliferation antigen in paraffin sections. However, satisfactory results were obtained only after subjecting tissue sections to microwave based antigen retrieval in citrate buffer solution. Other buffer solutions produce equivalent or better results and also permit use of the original Ki-67 antibody, which hitherto has been considered ineffective for paraffin sections.

  10. Generalized method for retrieving effective parameters of anisotropic metamaterials.

    PubMed

    Castanié, A; Mercier, J-F; Félix, S; Maurel, A

    2014-12-01

    Electromagnetic or acoustic metamaterials can be described in terms of equivalent effective, in general anisotropic, media and several techniques exist to determine the effective permeability and permittivity (or effective mass density and bulk modulus in the context of acoustics). Among these techniques, retrieval methods use the measured reflection and transmission coefficients (or scattering coefficients) for waves incident on a metamaterial slab containing few unit cells. Until now, anisotropic effective slabs have been considered in the literature but they are limited to the case where one of the axes of anisotropy is aligned with the slab interface. We propose an extension to arbitrary orientations of the principal axes of anisotropy and oblique incidence. The retrieval method is illustrated in the electromagnetic case for layered media, and in the acoustic case for array of tilted elliptical particles.

  11. Evaluation methods for retrieving information from interferograms of biomedical objects

    NASA Astrophysics Data System (ADS)

    Podbielska, Halina; Rottenkolber, Matthias

    1996-04-01

    Interferograms in the form of fringe patterns can be produced in two-beam interferometers, holographic or speckle interferometers, in setups realizing moire techniques or in deflectometers. Optical metrology based on the principle of interference can be applied as a testing tool in biomedical research. By analyzing of the fringe pattern images, information about the shape or mechanical behavior of the object under study can be retrieved. Here, some of the techniques for creating fringe pattern images were presented along with methods of analysis. Intensity based analysis as well as methods of phase measurements, are mentioned. Applications of inteferometric methods, especially in the field of experimental orthopedics, endoscopy and ophthalmology are pointed out.

  12. [ELISA method for the determination of factor VII antigen].

    PubMed

    Jorquera, J I; Aznar, J A; Monteagudo, J; Montoro, J M; Casaña, P; Pascual, I; Bañuls, E; Curats, R; Llopis, F

    1989-12-01

    The low plasma concentration of clotting factor VII makes it difficult to assay its antigenic fraction by the conventional methods of precipitation with specific antigens. Simple and peroxidase-conjugated antisera are currently available from commercial sources, thus allowing one to determine F VII:Ag by enzyme immunoassay. An ELISA method has been developed in this laboratory which provides sensitivity limits about 0.1% of the plasma concentration of F VII and correlates significantly with its functional activity (r = 0.603, n = 44, p less than 0.001). This technique can be highly helpful in characterising molecular variants of F VII, as well as in detecting acquired deficiencies of this factor.

  13. Improved retrievals of the optical properties of cirrus clouds by a combination of lidar methods.

    PubMed

    Cadet, Bertrand; Giraud, Vincent; Haeffelin, Martial; Keckhut, Philippe; Rechou, Anne; Baldy, Serge

    2005-03-20

    We focus on improvement of the retrieval of optical properties of cirrus clouds by combining two lidar methods. We retrieve the cloud's optical depth by using independently the molecular backscattering profile below and above the cloud [molecular integration (MI) method] and the backscattering profile inside the cloud with an a priori effective lidar ratio [particle integration (PI) method]. When the MI method is reliable, the combined MI-PI method allows us to retrieve the optimal effective lidar ratio. We compare these results with Raman lidar retrievals. We then use the derived optimal effective lidar ratio for retrieval with the PI method for situations in which the MI method cannot be applied.

  14. 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. PMID:25643512

  15. Mathematical, Logical, and Formal Methods in Information Retrieval: An Introduction to the Special Issue.

    ERIC Educational Resources Information Center

    Crestani, Fabio; Dominich, Sandor; Lalmas, Mounia; van Rijsbergen, Cornelis Joost

    2003-01-01

    Discusses the importance of research on the use of mathematical, logical, and formal methods in information retrieval to help enhance retrieval effectiveness and clarify underlying concepts of information retrieval. Highlights include logic; probability; spaces; and future research needs. (Author/LRW)

  16. Antigen retrieval using sodium hydroxide for prion immunohistochemistry in bovine spongiform encephalopathy and scrapie.

    PubMed

    Okada, H; Sato, Y; Sata, T; Sakurai, M; Endo, J; Yokoyama, T; Mohri, S

    2011-05-01

    Formalin-fixed and paraffin wax-embedded (FFPE) tissue sections are usually used for histopathological and immunohistochemical analyses in prion diseases in animals and man. However, formalin fixation cross-links proteins, reducing disease-associated prion protein (PrP(Sc)) immunolabelling. To detect PrP(Sc) in animals naturally affected with bovine spongiform encephalopathy (BSE) and scrapie, we applied minimal pretreatment with sodium hydroxide (NaOH). This simple pretreatment, combined with enzymatic digestion using proteinase K (PK), was equally effective in the detection of PrP(Sc) in FFPE tissue, and superior in terms of speed, compared with the usual autoclaving method. The most effective results, without any section loss, were obtained with 10 μg/ml PK in phosphate buffered saline containing 0.1% Triton-X at room temperature for 10 min and 150 mM NaOH at 60 °C for 10 min. By this simple procedure, PrP(Sc) was visualized in the brain of animals with BSE and scrapie using a range of anti-PrP primary antibodies.

  17. A TEMPERATURE AND ABUNDANCE RETRIEVAL METHOD FOR EXOPLANET ATMOSPHERES

    SciTech Connect

    Madhusudhan, N.; Seager, S.

    2009-12-10

    We present a new method to retrieve molecular abundances and temperature profiles from exoplanet atmosphere photometry and spectroscopy. We run millions of one-dimensional (1D) atmosphere models in order to cover the large range of allowed parameter space. In order to run such a large number of models, we have developed a parametric pressure-temperature (P-T) profile coupled with line-by-line radiative transfer, hydrostatic equilibrium, and energy balance, along with prescriptions for non-equilibrium molecular composition and energy redistribution. The major difference from traditional 1D radiative transfer models is the parametric P-T profile, which essentially means adopting energy balance only at the top of the atmosphere and not in each layer. We see the parametric P-T model as a parallel approach to the traditional exoplanet atmosphere models that rely on several free parameters to encompass unknown absorbers and energy redistribution. The parametric P-T profile captures the basic physical features of temperature structures in planetary atmospheres (including temperature inversions), and fits a wide range of published P-T profiles, including those of solar system planets. We apply our temperature and abundance retrieval method to the atmospheres of two transiting exoplanets, HD 189733b and HD 209458b, which have the best Spitzer and Hubble Space Telescope data available. For HD 189733b, we find efficient day-night redistribution of energy in the atmosphere, and molecular abundance constraints confirming the presence of H{sub 2}O, CO, CH{sub 4}, and CO{sub 2}. For HD 209458b, we confirm and constrain the dayside thermal inversion in an average 1D temperature profile. We also report independent detections of H{sub 2}O, CO, CH{sub 4}, and CO{sub 2} on the dayside of HD 209458b, based on six-channel Spitzer photometry. We report constraints for HD 189733b due to individual data sets separately; a few key observations are variable in different data sets at similar

  18. Immunolocalization of MAP-2 in Routinely Formalin-Fixed, Paraffin-Embedded Guinea Pig Brain Sections Using Microwave Irradiation: A Comparison of Different Combinations of Antibody Clones and Antigen Retrieval Buffer Solutions

    NASA Astrophysics Data System (ADS)

    Kan, Robert K.; Pleva, Christina M.; Hamilton, Tracey A.; Petrali, John P.

    2005-04-01

    The present study was designed to evaluate the efficacy of different microwave pretreatment methods to retrieve microtubule-associated protein 2 (MAP-2) immunoreactivity in formalin-fixed, paraffin-embedded guinea pig brain sections. Brain sections, microwave pretreated in boiling sodium citrate, citric acid, Tris hydrochloride, and EDTA buffers of pH 4, 6, and 8, were labeled with four different clones of MAP-2 monoclonal antibodies. No MAP-2 immunoreactivity was observed in control sections processed without microwave pretreatment. Optimal MAP-2 immunoreactivity was observed only when MAP-2 antibody clone AP18 was used in conjunction with citric acid buffer of pH 6.0. Using this combination, brain sections from nerve agent soman-exposed guinea pigs were found to exhibit marked reduction in MAP-2 immunostaining in the hippocampus. These observations suggest that the clone of the antibody in addition to the type and pH of antigen retrieval (AR) solution are important variables to be considered for establishing an optimal AR technique. When studying counterpart antigens of species other than that to which the antibodies were originally raised, different antibody clones must be tested in combination with different microwave-assisted AR (MAR) methods. This MAR method makes it possible to conduct retrospective studies on archival guinea pig brain paraffin blocks to evaluate changes in neuronal MAP-2 expression as a consequence of chemical warfare nerve agent toxicity.

  19. Quantitative cell imaging using single beam phase retrieval method

    NASA Astrophysics Data System (ADS)

    Anand, Arun; Chhaniwal, Vani; Javidi, Bahram

    2011-06-01

    Quantitative three-dimensional imaging of cells can provide important information about their morphology as well as their dynamics, which will be useful in studying their behavior under various conditions. There are several microscopic techniques to image unstained, semi-transparent specimens, by converting the phase information into intensity information. But most of the quantitative phase contrast imaging techniques is realized either by using interference of the object wavefront with a known reference beam or using phase shifting interferometry. A two-beam interferometric method is challenging to implement especially with low coherent sources and it also requires a fine adjustment of beams to achieve high contrast fringes. In this letter, the development of a single beam phase retrieval microscopy technique for quantitative phase contrast imaging of cells using multiple intensity samplings of a volume speckle field in the axial direction is described. Single beam illumination with multiple intensity samplings provides fast convergence and a unique solution of the object wavefront. Three-dimensional thickness profiles of different cells such as red blood cells and onion skin cells were reconstructed using this technique with an axial resolution of the order of several nanometers.

  20. Beyond model antigens: high-dimensional methods for the analysis of antigen-specific T cells

    PubMed Central

    Newell, Evan W.; Davis, Mark M.

    2014-01-01

    Adaptive immune responses often begin with the formation of a molecular complex between a T cell receptor (TCR) and a peptide antigen bound to a major histocompatibility complex (MHC) molecule. These complexes are highly variable, however, due to the polymorphism of MHC genes, the random, inexact recombination of TCR gene segments and the vast array of possible self and pathogen peptide antigens. As a result, it has been very difficult to comprehensively study the TCR repertoire or identify and track more than a few antigen-specific T cells in mice or humans. For mouse studies, this had led to a reliance on model antigens and TCR transgenes. The study of limited human clinical samples, in contrast, requires techniques that can simultaneously survey phenotype, function and reactivity to many T cell epitopes. Thanks to recent advances in single-cell and cytometry methodologies, as well as high-throughput sequencing of the TCR repertoire, we now have or will soon have the tools needed to comprehensively analyze T-cell responses during health and disease. PMID:24441473

  1. Evaluation of contents-based image retrieval methods for a database of logos on drug tablets

    NASA Astrophysics Data System (ADS)

    Geradts, Zeno J.; Hardy, Huub; Poortman, Anneke; Bijhold, Jurrien

    2001-02-01

    In this research an evaluation has been made of the different ways of contents based image retrieval of logos of drug tablets. On a database of 432 illicitly produced tablets (mostly containing MDMA), we have compared different retrieval methods. Two of these methods were available from commercial packages, QBIC and Imatch, where the implementation of the contents based image retrieval methods are not exactly known. We compared the results for this database with the MPEG-7 shape comparison methods, which are the contour-shape, bounding box and region-based shape methods. In addition, we have tested the log polar method that is available from our own research.

  2. Standardization of immunohistochemistry for formalin-fixed, paraffin-embedded tissue sections based on the antigen-retrieval technique: from experiments to hypothesis.

    PubMed

    Shi, Shan-Rong; Liu, Cheng; Taylor, Clive R

    2007-02-01

    From a practical point of view, one of the most difficult issues in the standardization of IHC for FFPE tissue is the adverse influence of formalin upon antigenicity, as well as the great variation in fixation/processing procedures. Based on previous study, an additional study using four markers demonstrated the potential for obtaining equivalent IHC staining among FFPE tissue sections with periods of formalin fixation ranging from 6 hr to 30 days. On this basis, the following hypothesis is proposed. "The use of optimized AR protocols permits retrieval of specific proteins (antigens) from FFPE tissues to a defined and reproducible degree (expressed as R%), with reference to the amount of protein present in the original fresh/unfixed tissue". This hypothesis may also be presented mathematically: the protein amount in a fresh cell/tissue, expressed as Pf, produces an IHC signal in fresh tissue of integral(Pf). When the identical IHC staining plus AR treatment is applied to a FFPE tissue section, the IHC signal may be represented as integral (Pffpe). The degree of retrieval after AR (R%) is calculated as follows: R% = integral (Pffpe)/ integral (Pf) x 100%. The amount of protein in the FFPE tissue may then be derived as follows: Pffpe = Pf x R%. In a situation where optimized AR is 100% effective, the IHC signal would then be of equal strength in fresh tissue and FFPE tissue, and Pffpe= Pf. Further studies are designed to test the limitations of the proposed hypothesis.

  3. A joint method to retrieve directional ocean wave spectra from SAR and wave spectrometer data

    NASA Astrophysics Data System (ADS)

    Ren, Lin; Yang, Jingsong; Zheng, Gang; Wang, Juan

    2016-07-01

    This paper proposes a joint method to simultaneously retrieve wave spectra at different scales from spaceborne Synthetic Aperture Radar (SAR) and wave spectrometer data. The method combines the output from the two different sensors to overcome retrieval limitations that occur in some sea states. The wave spectrometer sensitivity coefficient is estimated using an effective significant wave height (SWH), which is an average of SAR-derived and wave spectrometer-derived SWH. This averaging extends the area of the sea surface sampled by the nadir beam of the wave spectrometer to improve the accuracy of the estimated sensitivity coefficient in inhomogeneous sea states. Wave spectra are then retrieved from SAR data using wave spectrometer-derived spectra as first guess spectra to complement the short waves lost in SAR data retrieval. In addition, the problem of 180° ambiguity in retrieved spectra is overcome using SAR imaginary cross spectra. Simulated data were used to validate the joint method. The simulations demonstrated that retrieved wave parameters, including SWH, peak wave length (PWL), and peak wave direction (PWD), agree well with reference parameters. Collocated data from ENVISAT advanced SAR (ASAR), the airborne wave spectrometer STORM, the PHAROS buoy, and the European Centre for Medium-Range Weather Forecasting (ECMWF) were then used to verify the proposed method. Wave parameters retrieved from STORM and two ASAR images were compared to buoy and ECMWF wave data. Most of the retrieved parameters were comparable to reference parameters. The results of this study show that the proposed joint retrieval method could be a valuable complement to traditional methods used to retrieve directional ocean wave spectra, particularly in inhomogeneous sea states.

  4. Comparisons of wind speed retrieval methods on C-band multi-polarization SAR measurements

    NASA Astrophysics Data System (ADS)

    Ren, Lin; Yang, Jingsong; Zheng, Gang; Wang, Juan; Wang, Difeng

    2014-10-01

    This paper compares the wind speed retrieval methods on C-band multi-polarization SAR measurements to find out the most appropriate one for each polarization data. The RADARSAT-2 SAR quad-polarization (VV+HH+VH+HV) data and NDBC buoy wind data were collocated. For VVpolarization, the retrieved wind speed are compared among four geophysical model function (GMF). For HH polarization, the retrieved wind speed are compared among four polarization ratio model (PR) based on CMOD5 GMF. For VH polarization, the retrieved wind speed are compared between two linear models. Comparisons show all of three polarimetric SAR data have the ability of retrieving wind speed. Based on the error analysis, the commendatory methods are proposed for each polarization.

  5. A multiplex method for the detection of serum antibodies against in silico-predicted tumor antigens.

    PubMed

    Reuschenbach, Miriam; Dörre, Jonathan; Waterboer, Tim; Kopitz, Jürgen; Schneider, Martin; Hoogerbrugge, Nicoline; Jäger, Elke; Kloor, Matthias; von Knebel Doeberitz, Magnus

    2014-12-01

    Humoral immune responses against tumor antigens are studied as indirect markers of antigen exposure and in cancer vaccine studies. An increasing number of tumor antigens potentially translated from mutant genes is identified by advances in genomic sequencing. They represent an interesting source for yet unknown immunogenic epitopes. We here describe a multiplex method using the Luminex technology allowing for the detection of antibodies against multiple in silico-predicted linear neo-antigens in large sets of sera. The approach included 32 synthetic biotinylated peptides comprising a predicted set of frameshift mutation-induced neo-antigens. The antigens were fused to a FLAG epitope to ensure monitoring antigen binding to avidin-linked microspheres in the absence of monoclonal antibodies. Analytical specificity of measured serum antibody reactivity was proven by the detection of immune responses in immunized rabbits and a colorectal cancer patient vaccinated with peptides included in the assay. The measured antibody responses were comparable to peptide ELISA, and inter-assay reproducibility of the multiplex approach was excellent (R (2) > 0.98) for 20 sera tested against all antigens. Our methodic approach represents a valuable platform to monitor antibody responses against predicted antigens. It may be used in individualized cancer vaccine studies, thereby extending the relevance beyond the model system in the presented approach.

  6. Retrieving Land Surface Temperature from Hyperspectral Thermal Infrared Data Using a Multi-Channel Method

    PubMed Central

    Zhong, Xinke; Huo, Xing; Ren, Chao; Labed, Jelila; Li, Zhao-Liang

    2016-01-01

    Land Surface Temperature (LST) is a key parameter in climate systems. The methods for retrieving LST from hyperspectral thermal infrared data either require accurate atmospheric profile data or require thousands of continuous channels. We aim to retrieve LST for natural land surfaces from hyperspectral thermal infrared data using an adapted multi-channel method taking Land Surface Emissivity (LSE) properly into consideration. In the adapted method, LST can be retrieved by a linear function of 36 brightness temperatures at Top of Atmosphere (TOA) using channels where LSE has high values. We evaluated the adapted method using simulation data at nadir and satellite data near nadir. The Root Mean Square Error (RMSE) of the LST retrieved from the simulation data is 0.90 K. Compared with an LST product from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on Meteosat, the error in the LST retrieved from the Infared Atmospheric Sounding Interferometer (IASI) is approximately 1.6 K. The adapted method can be used for the near-real-time production of an LST product and to provide the physical method to simultaneously retrieve atmospheric profiles, LST, and LSE with a first-guess LST value. The limitations of the adapted method are that it requires the minimum LSE in the spectral interval of 800–950 cm−1 larger than 0.95 and it has not been extended for off-nadir measurements. PMID:27187408

  7. Retrieving Land Surface Temperature from Hyperspectral Thermal Infrared Data Using a Multi-Channel Method.

    PubMed

    Zhong, Xinke; Huo, Xing; Ren, Chao; Labed, Jelila; Li, Zhao-Liang

    2016-01-01

    Land Surface Temperature (LST) is a key parameter in climate systems. The methods for retrieving LST from hyperspectral thermal infrared data either require accurate atmospheric profile data or require thousands of continuous channels. We aim to retrieve LST for natural land surfaces from hyperspectral thermal infrared data using an adapted multi-channel method taking Land Surface Emissivity (LSE) properly into consideration. In the adapted method, LST can be retrieved by a linear function of 36 brightness temperatures at Top of Atmosphere (TOA) using channels where LSE has high values. We evaluated the adapted method using simulation data at nadir and satellite data near nadir. The Root Mean Square Error (RMSE) of the LST retrieved from the simulation data is 0.90 K. Compared with an LST product from the Spinning Enhanced Visible and Infrared Imager (SEVIRI) on Meteosat, the error in the LST retrieved from the Infared Atmospheric Sounding Interferometer (IASI) is approximately 1.6 K. The adapted method can be used for the near-real-time production of an LST product and to provide the physical method to simultaneously retrieve atmospheric profiles, LST, and LSE with a first-guess LST value. The limitations of the adapted method are that it requires the minimum LSE in the spectral interval of 800-950 cm(-1) larger than 0.95 and it has not been extended for off-nadir measurements. PMID:27187408

  8. Successful Retrieval of Uncoiled Coronary Guidewire Using Simple Balloon Method.

    PubMed

    Patil, Shivanand; Ramalingam, Rangraj; Kharge, Jayashree; Nayak, Mohan; Manjunath, Cholenahally Nanjappa

    2015-10-01

    Breakage of angioplasty device in coronary artery can cause panic in the catheterization laboratory. These broken fragments may serve as a nidus for thrombus formation; hence, removal of these fragments becomes mandatory. Since the incidence of guidewire fracture during angioplasty are rarely reported, evidence-based approaches are not available for the management of such incidental conditions. Here, we report an interesting case of entrapment and unravelling of guidewire. We successfully retrieved unravelled guidewire using a noncompliant balloon inflated in the guiding catheter. Subsequently, the procedure was completed successfully with an implantation of a stent in the culprit lesion. We are of opinion that this novel technique is quite easy and less cumbersome than other described techniques reported earlier. PMID:26557557

  9. Adjusted Levenberg-Marquardt method application to methene retrieval from IASI/METOP spectra

    NASA Astrophysics Data System (ADS)

    Khamatnurova, Marina; Gribanov, Konstantin

    2016-04-01

    Levenberg-Marquardt method [1] with iteratively adjusted parameter and simultaneous evaluation of averaging kernels together with technique of parameters selection are developed and applied to the retrieval of methane vertical profiles in the atmosphere from IASI/METOP spectra. Retrieved methane vertical profiles are then used for calculation of total atmospheric column amount. NCEP/NCAR reanalysis data provided by ESRL (NOAA, Boulder,USA) [2] are taken as initial guess for retrieval algorithm. Surface temperature, temperature and humidity vertical profiles are retrieved before methane vertical profile retrieval for each selected spectrum. Modified software package FIRE-ARMS [3] were used for numerical experiments. To adjust parameters and validate the method we used ECMWF MACC reanalysis data [4]. Methane columnar values retrieved from cloudless IASI spectra demonstrate good agreement with MACC columnar values. Comparison is performed for IASI spectra measured in May of 2012 over Western Siberia. Application of the method for current IASI/METOP measurements are discussed. 1.Ma C., Jiang L. Some Research on Levenberg-Marquardt Method for the Nonlinear Equations // Applied Mathematics and Computation. 2007. V.184. P. 1032-1040 2.http://www.esrl.noaa.gov/psdhttp://www.esrl.noaa.gov/psd 3.Gribanov K.G., Zakharov V.I., Tashkun S.A., Tyuterev Vl.G.. A New Software Tool for Radiative Transfer Calculations and its application to IMG/ADEOS data // JQSRT.2001.V.68.№ 4. P. 435-451. 4.http://www.ecmwf.int/http://www.ecmwf.int

  10. A method for retrieving the directional ocean wave spectra from synthetic aperture radar image

    NASA Astrophysics Data System (ADS)

    Ren, Lin; Yang, Jingsong; Chen, Peng

    2012-09-01

    Directional ocean wave spectra can describe the energy distribution of ocean wave and play an important role in oceanography. Synthetic aperture radar (SAR) can measure wave spectra based on a nonlinear mapping model between the image spectra (or cross spectra) and wave spectra. Due to the complexity of variable estimation and wave number cut off in azimuth direction in the mapping process, some scientists have been endeavoring to improve the retrieval of wave spectra. The paper proposes a method for the retrieval, which don't depend on any external information except wind direction. It separates into two parts. In part 1, the spectra for real image or the cross spectra for complex image are calculated. And the modulation transfer function (MTF) is estimated including real aperture radar (RAR) MTF and velocity bunching. Then the wave spectra are retrieved by direct dividing based on the quasi-linear relation. The 180° ambiguity is removed from the imaginary part of cross spectra or the wind direction. The significant wave height (Hs), peak wave wavelength (L) and peak wave direction (D) are extracted from the retrieval. If the angle between the D and the azimuth direction is higher than 45°, the retrieval is finished. If the angle is lower than 45°, we go on retrieving. In part 2, the first guess spectra are needed to compensate the lost wave information, which can be parametrically constructed based on the retrieved wave spectra in part 1. Finally the wave spectra are iteratively retrieved from the first guess spectra based on the nonlinear relation. The Envisat ASAR images are used to validate the method. In case 1, the RMSE between this method and SARTool on D, L, Hs is 7.6°, 19.7 m, 0.18 m respectively. In case 2, the RMSE between this method and Jason-1 on Hs is 0.5 m.

  11. Identification of Hog Cholera Viral Antigen by Immunofluorescence. Application as a Diagnostic and Assay Method.

    PubMed

    Mengeling, W L; Pirtle, E C; Torrey, J P

    1963-10-01

    In the absence of detectable cytologic changes in hog cholera virus-infected tissue culture cells, hog cholera viral antigen was readily detected by immunofluorescence. The ability to detect hog cholera viral antigen by this method allowed for determination of infectivity titers and also for titration of homologous antibody. Immunofluorescence made possible the identification, in tissue culture, of hog cholera virus from blood, serum, and spleen extracts of experimentally infected swine. Further applications of this method and its limitations are being investigated.

  12. Retrieval of spheroidal particle size distribution using the approximate method in spectral extinction technique

    NASA Astrophysics Data System (ADS)

    Wang, Li; Sun, Xiaogang; Xing, Jian

    2012-04-01

    Retrieval of spheroidal particle size distribution using an approximate method in spectral extinction technique is proposed. The combined approximate method, which is the combination of Mie method and generalized eikonal approximation (GEA) method, is used as an alternative to the rigorous solutions to calculate the averaging extinction efficiency of spheroid. Based on the averaging extinction efficiency, the accuracy and limitations of the retrieval are then investigated. Moreover, the validity range and effect of the refractive index are also examined. The Johnson's SB function in this paper is used as a versatile function to fit the commonly used particle size distribution functions in the dependent model. Simulations and experimental results show that the combined approximate method can be successfully applied to retrieval of spheroidal particle size distribution. In certain constraint conditions, the retrieval results demonstrate the high reliability and stability of the method. By using the combined approximate method, the complexity and computation time of the retrieval are significantly reduced, which is more suitable for quick and easy measurement. The method can also be used as a replacement when the rigorous solutions suffer computationally intractable difficulties.

  13. Study on the methods of retrieving urban winter LST based on the Landsat TM 6

    NASA Astrophysics Data System (ADS)

    Zhao, Jingjing; Pei, Liang; Huang, HuiPing; Li, XiaoSong

    2009-10-01

    Presently, there are three methods of retrieving land surface temperature based on TM thermal infrared band (band 6). These methods are: the Radiative transfer equation (RTE), the Mono-window algorithm and the General single channel algorithm. Due to the general unavailability of situatmospheric profile data, the RTE method is seldom applied. Though the other two methods are relatively widely researched, the fields are almost limited on the urban hot island study by retrieving hot seasonal temperature. With the increasing emphasis of city energy saving in China and the increasing heating energy consumption, more researchers are beginning to study the construction of city buildings and hot diffusion in winter with remote sensing methods. In order to judge which one of the other two LST retrieval methods is optimal to retrieve cold seasonal temperature, this paper focuses on the retrieval of cold seasonal LST from the Landsat TM6 data. This data was captured on 4th Jan 2007 over the Xi Cheng District in Beijing by using the Mono-window algorithm and the General single channel algorithm. The results indicate that, both methods can produce a similar LST spatial distribution. However, with the higher relative precision, the Mono-window algorithm proved to be more suitable than the General single channel algorithm to this research area. Furthermore, the author presents some suggestions on the choice of winter temperature LST methods.

  14. Two Surface Temperature Retrieval Methods Compared Over Agricultural Lands

    NASA Technical Reports Server (NTRS)

    French, Andrew N.; Schmugge, Thomas J.; Jacob, Frederic; Ogawa, Kenta; Houser, Paul R. (Technical Monitor)

    2002-01-01

    Accurate, spatially distributed surface temperatures are required for modeling evapotranspiration (ET) over agricultural fields under wide ranging conditions, including stressed and unstressed vegetation. Modeling approaches that use surface temperature observations, however, have the burden of estimating surface emissivities. Emissivity estimation, the subject of much recent research, is facilitated by observations in multiple thermal infrared bands. But it is nevertheless a difficult task. Using observations from a multiband thermal sensor, the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), estimated surface emissivities and temperatures are retrieved in two different ways: the temperature emissivity separation approach (TES) and the normalized emissivity approach (NEM). Both rely upon empirical relationships, but the assumed relationships are different. TES relies upon a relationship between the minimum spectral emissivity and the range of observed emissivities. NEM relies upon an assumption that at least one thermal band has a pre-determined emissivity (close to 1.0). The benefits and consequences of each approach will be demonstrated for two different landscapes: one in central Oklahoma, USA and another in southern New Mexico.

  15. The Continuous Monitoring of Desert Dust using an Infrared-based Dust Detection and Retrieval Method

    NASA Technical Reports Server (NTRS)

    Duda, David P.; Minnis, Patrick; Trepte, Qing; Sun-Mack, Sunny

    2006-01-01

    Airborne dust and sand are significant aerosol sources that can impact the atmospheric and surface radiation budgets. Because airborne dust affects visibility and air quality, it is desirable to monitor the location and concentrations of this aerosol for transportation and public health. Although aerosol retrievals have been derived for many years using visible and near-infrared reflectance measurements from satellites, the detection and quantification of dust from these channels is problematic over bright surfaces, or when dust concentrations are large. In addition, aerosol retrievals from polar orbiting satellites lack the ability to monitor the progression and sources of dust storms. As a complement to current aerosol dust retrieval algorithms, multi-spectral thermal infrared (8-12 micron) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Meteosat-8 Spinning Enhanced Visible and Infrared Imager (SEVIRI) are used in the development of a prototype dust detection method and dust property retrieval that can monitor the progress of Saharan dust fields continuously, both night and day. The dust detection method is incorporated into the processing of CERES (Clouds and the Earth s Radiant Energy System) aerosol retrievals to produce dust property retrievals. Both MODIS (from Terra and Aqua) and SEVERI data are used to develop the method.

  16. A content-based image retrieval method for optical colonoscopy images based on image recognition techniques

    NASA Astrophysics Data System (ADS)

    Nosato, Hirokazu; Sakanashi, Hidenori; Takahashi, Eiichi; Murakawa, Masahiro

    2015-03-01

    This paper proposes a content-based image retrieval method for optical colonoscopy images that can find images similar to ones being diagnosed. Optical colonoscopy is a method of direct observation for colons and rectums to diagnose bowel diseases. It is the most common procedure for screening, surveillance and treatment. However, diagnostic accuracy for intractable inflammatory bowel diseases, such as ulcerative colitis (UC), is highly dependent on the experience and knowledge of the medical doctor, because there is considerable variety in the appearances of colonic mucosa within inflammations with UC. In order to solve this issue, this paper proposes a content-based image retrieval method based on image recognition techniques. The proposed retrieval method can find similar images from a database of images diagnosed as UC, and can potentially furnish the medical records associated with the retrieved images to assist the UC diagnosis. Within the proposed method, color histogram features and higher order local auto-correlation (HLAC) features are adopted to represent the color information and geometrical information of optical colonoscopy images, respectively. Moreover, considering various characteristics of UC colonoscopy images, such as vascular patterns and the roughness of the colonic mucosa, we also propose an image enhancement method to highlight the appearances of colonic mucosa in UC. In an experiment using 161 UC images from 32 patients, we demonstrate that our method improves the accuracy of retrieving similar UC images.

  17. Evaluation of semantic-based information retrieval methods in the autism phenotype domain.

    PubMed

    Hassanpour, Saeed; O'Connor, Martin J; Das, Amar K

    2011-01-01

    Biomedical ontologies are increasingly being used to improve information retrieval methods. In this paper, we present a novel information retrieval approach that exploits knowledge specified by the Semantic Web ontology and rule languages OWL and SWRL. We evaluate our approach using an autism ontology that has 156 SWRL rules defining 145 autism phenotypes. Our approach uses a vector space model to correlate how well these phenotypes relate to the publications used to define them. We compare a vector space phenotype representation using class hierarchies with one that extends this method to incorporate additional semantics encoded in SWRL rules. From a PubMed-extracted corpus of 75 articles, we show that average rank of a related paper using the class hierarchy method is 4.6 whereas the average rank using the extended rule-based method is 3.3. Our results indicate that incorporating rule-based definitions in information retrieval methods can improve search for relevant publications.

  18. [Virion precipitation reaction based on determination of reverse transcriptase activity: Method of study of membrane antigens of oncornaviruses].

    PubMed

    Zakharova, L G; Al'tshtein, A D

    1978-01-01

    A method for the study of the envelope antigens of oncornaviruses of C, B, and D types by the virion precipitation test (VPT) based on the measurement of the amount of precipitated virus by its reverse transcriptase activity is described. The method is immunologically specific for titration of antibody to the envelope antigens of oncornaviruses. By means of the VPT it is possible to identify oncornaviruses, to study antigenic relationships between them and to detect some or other antigens in virion coat.

  19. Description and validation of a limb scatter retrieval method for Odin/OSIRIS

    NASA Astrophysics Data System (ADS)

    Tukiainen, S.; Hassinen, S.; SeppäLä, A.; Auvinen, H.; KyröLä, E.; Tamminen, J.; Haley, C. S.; Lloyd, N.; Verronen, P. T.

    2008-02-01

    In this paper we present the Modified Onion Peeling (MOP) inversion method, which is for the first time used to retrieve vertical profiles of stratospheric trace gases from Odin/OSIRIS limb scatter measurements. Since the original publication of the method in 2002, the method has undergone major modifications discussed here. The MOP method now uses a spectral microwindow for the NO2 retrieval, instead of the wide UV-visible band used for the ozone, air, and aerosol retrievals. We give a brief description of the algorithm itself and show its performance with both simulated and real data. Retrieved ozone and NO2 profiles from the OSIRIS measurements were compared with data from the GOMOS and HALOE instruments. No more than 5% difference was found between OSIRIS daytime and GOMOS nighttime ozone profiles between 21 and 45 km. The difference between OSIRIS and HALOE sunset NO2 mixing ratio profiles was at most 25% between 20 and 40 km. The neutral air density was compared with the ECMWF analyzed data and around 5% difference was found at altitudes from 20 to 55 km. However, OSIRIS observations yield as much as 80% greater aerosols number density than GOMOS observations between 15 and 35 km. These validation results indicate that the quality of MOP ozone, NO2, and neutral air is good. The new version of the method introduced here is also easily expanded to retrieve additional species of interest.

  20. Comparison of neural networks and regression-based methods for temperature retrievals.

    PubMed

    Motteler, H E; Strow, L L; McMillin, L; Gualtieri, J A

    1995-08-20

    Two methods for performing clear-air temperature retrievals from simulated radiances for the Atmospheric Infrared Sounder are investigated. Neural networks are compared with a well-known linear method in which regression is performed after a change of bases. With large channel sets, both methods can rapidly perform clear-air retrievals over a variety of climactic conditions with an overall RMS error of less than 1 K. The Jacobian of the neural network is compared with the Jacobian (the regression coefficients) of the linear method, revealing a more fine-scale variation than expected from the underlying physics, particularly for the neural net. Some pragmatic information concerning the application ofneural nets to retrieval problems is also included.

  1. Microwave-assisted antigen retrieval and incubation with cox-2 antibody of archival paraffin-embedded human oligodendroglioma and astrocytomas.

    PubMed

    Temel, Sehime G; Minbay, F Zehra; Kahveci, Zeynep; Jennes, Lothar

    2006-09-30

    Immunohistochemistry is an important tool that is often used for the diagnosis of pathologies; however, the length of time required to process the tissue is relatively long. Furthermore, the quality and sensitivity of immunohistochemical staining is affected by formalin fixation which results in variable loss of antigenicity, known as masking effect. Here we assess the effect of microwave irradiation on the incubation time required to obtain high quality immunohistochemical staining for cox-2 using archival formalin-fixed, paraffin-embedded human oligodendrogliomas and astrocytomas. The results show that intermittent microwave irradiation during the incubation with the primary antibody reduced the time requirement to 5 min while the staining quality was indistinguishable from 1 or 24 h long incubations. Thus, the use of this procedure results in a significant saving of time which is important for a timely diagnosis of pathological conditions that await treatment.

  2. An Efficient Method for Rare Spectra Retrieval in Astronomical Databases

    NASA Astrophysics Data System (ADS)

    Du, Changde; Luo, Ali; Yang, Haifeng; Hou, Wen; Guo, Yanxin

    2016-03-01

    One of the most important aims of astronomical data mining is to systematically search for specific rare objects in a massive spectral data set, given a small fraction of identified samples with the same type. Most existing methods are mainly based on binary classification, which usually suffers from incompleteness when there are too few known samples. Rank-based methods could provide good solutions for such cases. After investigating several algorithms, a method combining a bipartite ranking model with bootstrap aggregating techniques was developed in this paper. The method was applied while searching for carbon stars in the spectral data of Sloan Digital Sky Survey Data Release 10 and compared with several other popular methods used for data mining. Experimental results validate that the proposed method is not only the most effective but also the least time-consuming technique among its competitors when searching for rare spectra in a large but unlabeled data set.

  3. A novel method of retrieving the polarization qubits after being transmitted in turbid media

    NASA Astrophysics Data System (ADS)

    Xu, Qiang; Guo, Zhongyi; Tao, Qiangqiang; Jiao, Weiyan; Qu, Shiliang; Gao, Jun

    2015-03-01

    In this paper, we have mainly investigated the reconstruction of the polarization states of the incident light which passed through the turbid atmospheric media. Here, a novel polarization retrieve (PR) method is established using a Monte Carlo simulation algorithm, which is proposed to study the influence of particle scattering. The polarization states of the initial field could be retrieved accurately according to the polarization states of the scattered field and the Mueller matrix. In the case of a single homogeneous medium, the mean error of retrieved polarization is close to zero. We have also applied this method to complex atmospheric environments such as random-sized distribution particles and various index of refraction media. By comparison with the existing polarization maintaining method, the results indicate that the PR method is more applicable to disordered media with relatively larger particles. Moreover, the errors of the retrieved degree of polarization are below 0.11%, and the errors of the retrieved angle of polarization are below 0.54% in our mixed media model. So, this work will be very significant for polarizing quantum secure communication in scattering medium over a long-distance scope.

  4. Texture based feature extraction methods for content based medical image retrieval systems.

    PubMed

    Ergen, Burhan; Baykara, Muhammet

    2014-01-01

    The developments of content based image retrieval (CBIR) systems used for image archiving are continued and one of the important research topics. Although some studies have been presented general image achieving, proposed CBIR systems for archiving of medical images are not very efficient. In presented study, it is examined the retrieval efficiency rate of spatial methods used for feature extraction for medical image retrieval systems. The investigated algorithms in this study depend on gray level co-occurrence matrix (GLCM), gray level run length matrix (GLRLM), and Gabor wavelet accepted as spatial methods. In the experiments, the database is built including hundreds of medical images such as brain, lung, sinus, and bone. The results obtained in this study shows that queries based on statistics obtained from GLCM are satisfied. However, it is observed that Gabor Wavelet has been the most effective and accurate method. PMID:25227014

  5. Texture based feature extraction methods for content based medical image retrieval systems.

    PubMed

    Ergen, Burhan; Baykara, Muhammet

    2014-01-01

    The developments of content based image retrieval (CBIR) systems used for image archiving are continued and one of the important research topics. Although some studies have been presented general image achieving, proposed CBIR systems for archiving of medical images are not very efficient. In presented study, it is examined the retrieval efficiency rate of spatial methods used for feature extraction for medical image retrieval systems. The investigated algorithms in this study depend on gray level co-occurrence matrix (GLCM), gray level run length matrix (GLRLM), and Gabor wavelet accepted as spatial methods. In the experiments, the database is built including hundreds of medical images such as brain, lung, sinus, and bone. The results obtained in this study shows that queries based on statistics obtained from GLCM are satisfied. However, it is observed that Gabor Wavelet has been the most effective and accurate method.

  6. An Information Retrieval Model Based on Vector Space Method by Supervised Learning.

    ERIC Educational Resources Information Center

    Tai, Xiaoying; Ren, Fuji; Kita, Kenji

    2002-01-01

    Proposes a method to improve retrieval performance of the vector space model by using users' relevance feedback. Discusses the use of singular value decomposition and the latent semantic indexing model, and reports the results of two experiments that show the effectiveness of the proposed method. (Author/LRW)

  7. Time-Quality Tradeoff of Waiting Strategies for Tutors to Retrieve Relevant Teaching Methods

    ERIC Educational Resources Information Center

    Shih, Wen-Chung; Tseng, Shian-Shyong; Yang, Che-Ching; Liang, Tyne

    2011-01-01

    As more and more undergraduate students act as voluntary tutors to rural pupils after school, there is a growing need for a supporting environment to facilitate adaptive instruction. Among others, a teaching method retrieval system is intended to help tutors find relevant teaching methods for teaching a particular concept. However, teaching…

  8. A neural network based error correction method for radio occultation electron density retrieval

    NASA Astrophysics Data System (ADS)

    Pham, Viet-Cuong; Juang, Jyh-Ching

    2015-12-01

    Abel inversion techniques have been widely employed to retrieve electron density profiles (EDPs) from radio occultation (RO) measurements, which are available by observing Global Navigation Satellite System (GNSS) satellites from low-earth-orbit (LEO) satellites. It is well known that the ordinary Abel inversion might introduce errors in the retrieval of EDPs when the spherical symmetry assumption is violated. The error, however, is case-dependent; therefore it is desirable to associate an error index or correction coefficient with respect to each retrieved EDP. Several error indices have been proposed but they only deal with electron density at the F2 peak and suffer from some drawbacks. In this paper we propose an artificial neural network (ANN) based error correction method for EDPs obtained by the ordinary Abel inversion. The ANN is first trained to learn the relationship between vertical total electron content (TEC) measurements and retrieval errors at the F2 peak, 220 km and 110 km altitudes; correction coefficients are then estimated to correct the retrieved EDPs at these three altitudes. Experiments using the NeQuick2 model and real FORMOSAT-3/COSMIC RO geometry show that the proposed method outperforms existing ones. Real incoherent scatter radar (ISR) measurements at the Jicamarca Radio Observatory and the global TEC map provided by the International GNSS Service (IGS) are also used to valid the proposed method.

  9. A Yeast Display Immunoprecipitation Method for Efficient Isolation and Characterization of Antigens

    PubMed Central

    Cho, Yong Ku; Chen, Irene; Wei, Xin; Li, Lingjun; Shusta, Eric V.

    2009-01-01

    Yeast antibody display has found a wide variety of applications including antibody affinity maturation, epitope mapping, and library screening. Here we report a yeast display immunoprecipitation (YDIP) technique that employs yeast cells displaying single-chain antibody fragments (scFv) on their surface as affinity capture reagents to isolate and characterize antigens. We show that displayed single-chain antibody fragments are active in a variety of detergent solutions commonly used for immunoprecipitation and that the antigen-antibody interaction can be accurately quantified by YDIP coupled with flow cytometry. The YDIP method has also been optimized so that it is compatible with commonly used protein characterization tools such as Western blotting, silver staining, and mass spectrometry. From complex protein mixtures, we have used YDIP to isolate, analyze and sequence both soluble and plasma membrane antigens using tandem mass spectrometry. In the case of the membrane antigen, YDIP coupled with tandem mass spectrometry was successful in identifying neural cell adhesion molecule (NCAM) as the antigen for an antibody previously selected as binding to the plasma membranes of endothelial cells. The presented method therefore has potential to facilitate antibody-antigen characterization. PMID:19041873

  10. [A new retrieval method for ozone concentration at the troposphere based on differential absorption lidar].

    PubMed

    Fan, Guang-Qiang; Liu, Jian-Guo; Liu, Wen-Qing; Lu, Yi-Huai; Zhang, Tian-Shu; Dong, Yun-Sheng; Zhao, Xue-Song

    2012-12-01

    Aerosols interfere with differential absorption lidar ozone concentration measurement and can introduce significant errors. A new retrieval method was introduced, and ozone concentration and aerosol extinction coefficient were gained simultaneously based on the retrieval method. The variables were analyzed by experiment including aerosol lidar ratio, aerosol wavelength exponent, and aerosol-molecular ratio at the reference point. The results show that these parameters introduce error less than 8% below 1 km. The measurement error derives chiefly from signal noise and the parameters introduce error less than 3% above 1 km. Finally the vertical profile of tropospheric ozone concentration and aerosol extinction coefficient were derived by using this algorithm. The retrieval results of the algorithm and traditional dual-wavelength difference algorithm are compared and analyzed. Experimental results indicate that the algorithm is feasible, and the algorithm can reduce differential absorption lidar measurement error introduced by aerosol.

  11. An improved stair phase encoding method for absolute phase retrieval

    NASA Astrophysics Data System (ADS)

    Zhou, Canlin; Liu, Tongchuan; Si, Shuchun; Xu, Jianqiang; Liu, Yepeng; Lei, Zhenkun

    2015-03-01

    An improved phase unwrapping method is proposed to reduce the projection fringes in three-dimensional (3D) surface measurement. Color fringe patterns are generated by encoding with sinusoidal fringe and stair phase fringe patterns in red and blue channels. These color fringe patterns are projected onto the tested objects and then captured by a color CCD camera. The recorded fringe patterns are separated into their RGB components. Two groups of four-step phase-shifting fringe patterns are obtained. One group of the stripes are four sinusoidal patterns, which are used to determine the wrapped phase. The other group of stripes are four sinusoidal patterns with the codeword embedded into stair phase, whose stair changes are perfectly aligned with the 2π discontinuities of sinusoidal fringe phase, which are used to determine the fringe order for the phase unwrapping. The experimental results are analyzed and compared with those of the method in Zheng and Da (2012. Opt Express 20(22):24139-24150). The results show that the proposed method needs only four fringe patterns while having less error. It can effectively reduce the number of projection fringes and improve the measuring speed.

  12. Retrieval of Temperature and Water Vapour from Multiple Channel Lidar Systems Using an Optimal Estimation Method

    NASA Astrophysics Data System (ADS)

    Sica, Robert; Haefele, Alexander

    2016-04-01

    While the application of optimal estimation methods (OEMs) is well-known for the retrieval of atmospheric parameters from passive instruments, active instruments have typically not employed the OEM. For instance, the measurement of temperature in the middle atmosphere with Rayleigh-scatter lidars is an important technique for assessing atmospheric change. Current retrieval schemes for these temperatures have several shortcomings which can be overcome using an OEM. Forward models have been constructed that fully characterize the measurement and allow the simultaneous retrieval of temperature, dead time and background. The OEM allows a full uncertainty budget to be obtained on a per profile basis that includes, in addition to the statistical uncertainties, the smoothing error and uncertainties due to Rayleigh extinction, ozone absorption, the lidar constant, nonlinearity in the counting system, variation of the Rayleigh-scatter cross section with altitude, pressure, acceleration due to gravity and the variation of mean molecular mass with altitude. The vertical resolution of the temperature profile is found at each height, and a quantitative determination is made of the maximum height to which the retrieval is valid. A single temperature profile can be retrieved from measurements with multiple channels that cover different height ranges, vertical resolutions and even different detection methods. The OEM employed is shown to give robust estimates of temperature consistent with previous methods, while requiring minimal computational time. Retrieval of water vapour mixing ratio from vibrational Raman scattering lidar measurements is another example where an OEM offers a considerable advantage over the standard analysis technique, with the same advantages as discussed above for Rayleigh-scatter temperatures but with an additional benefit. The conversion of the lidar measurement into mixing ratio requires a calibration constant to be employed. Using OEM the calibration

  13. Noninvasive method for retrieval of broken dental implant abutment screw

    PubMed Central

    Gooty, Jagadish Reddy; Palakuru, Sunil Kumar; Guntakalla, Vikram Reddy; Nera, Mahipal

    2014-01-01

    Dental implants made of titanium for replacement of missing teeth are widely used because of ease of technical procedure and high success rate, but are not free of complications and may fail. Fracturing of the prosthetic screw continues to be a problem in restorative practice and great challenge to remove the fractured screw conservatively. This case report describes and demonstrates the technique of using an ultrasonic scaler in the removal of the fracture screw fragment as a noninvasive method without damaging the hex of implants. PMID:24963261

  14. An improved method for retrieving nighttime aerosol optical thickness from the VIIRS Day/Night Band

    NASA Astrophysics Data System (ADS)

    McHardy, T. M.; Zhang, J.; Reid, J. S.; Miller, S. D.; Hyer, E. J.; Kuehn, R. E.

    2015-11-01

    Using Visible Infrared Imaging Radiometer Suite (VIIRS) Day/Night Band (DNB) data, a method, dubbed the "variance method", is developed for retrieving nighttime aerosol optical thickness (τ) values through the examination of the dispersion of radiance values above an artificial light source. Based on the improvement of a previous algorithm, this updated method derives a semi-quantitative indicator of nighttime τ using artificial light sources. Nighttime τ retrievals from the newly developed method are inter-compared with an interpolated value from late afternoon and early morning ground observations from four AErosol RObotic NETwork (AERONET) sites as well as column-integrated τ from one High Spectral Resolution Lidar (HSRL) site at Huntsville, AL, during the NASA Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) campaign, providing full diel coverage. Sensitivity studies are performed to examine the effects of lunar illumination on VIIRS τ retrievals made via the variance method, revealing that lunar contamination may have a smaller impact than previously thought; however, the small sample size of this study limits the conclusiveness thus far. VIIRS τ retrievals yield a coefficient of determination (r2) of 0.60 and a root-mean-squared error (RMSE) of 0.18 when compared against straddling daytime-averaged AERONET τ values. Preliminary results suggest that artificial light sources can be used for estimating regional and global nighttime aerosol distributions in the future.

  15. Dual-Force ISOMAP: A New Relevance Feedback Method for Medical Image Retrieval

    PubMed Central

    Shen, Hualei; Tao, Dacheng; Ma, Dianfu

    2013-01-01

    With great potential for assisting radiological image interpretation and decision making, content-based image retrieval in the medical domain has become a hot topic in recent years. Many methods to enhance the performance of content-based medical image retrieval have been proposed, among which the relevance feedback (RF) scheme is one of the most promising. Given user feedback information, RF algorithms interactively learn a user’s preferences to bridge the “semantic gap” between low-level computerized visual features and high-level human semantic perception and thus improve retrieval performance. However, most existing RF algorithms perform in the original high-dimensional feature space and ignore the manifold structure of the low-level visual features of images. In this paper, we propose a new method, termed dual-force ISOMAP (DFISOMAP), for content-based medical image retrieval. Under the assumption that medical images lie on a low-dimensional manifold embedded in a high-dimensional ambient space, DFISOMAP operates in the following three stages. First, the geometric structure of positive examples in the learned low-dimensional embedding is preserved according to the isometric feature mapping (ISOMAP) criterion. To precisely model the geometric structure, a reconstruction error constraint is also added. Second, the average distance between positive and negative examples is maximized to separate them; this margin maximization acts as a force that pushes negative examples far away from positive examples. Finally, the similarity propagation technique is utilized to provide negative examples with another force that will pull them back into the negative sample set. We evaluate the proposed method on a subset of the IRMA medical image dataset with a RF-based medical image retrieval framework. Experimental results show that DFISOMAP outperforms popular approaches for content-based medical image retrieval in terms of accuracy and stability. PMID:24391891

  16. High sensitivity phase retrieval method in grating-based x-ray phase contrast imaging

    SciTech Connect

    Wu, Zhao; Gao, Kun; Chen, Jian; Wang, Dajiang; Wang, Shenghao; Chen, Heng; Bao, Yuan; Shao, Qigang; Wang, Zhili; Zhang, Kai; Zhu, Peiping; Wu, Ziyu

    2015-02-15

    Purpose: Grating-based x-ray phase contrast imaging is considered as one of the most promising techniques for future medical imaging. Many different methods have been developed to retrieve phase signal, among which the phase stepping (PS) method is widely used. However, further practical implementations are hindered, due to its complex scanning mode and high radiation dose. In contrast, the reverse projection (RP) method is a novel fast and low dose extraction approach. In this contribution, the authors present a quantitative analysis of the noise properties of the refraction signals retrieved by the two methods and compare their sensitivities. Methods: Using the error propagation formula, the authors analyze theoretically the signal-to-noise ratios (SNRs) of the refraction images retrieved by the two methods. Then, the sensitivities of the two extraction methods are compared under an identical exposure dose. Numerical experiments are performed to validate the theoretical results and provide some quantitative insight. Results: The SNRs of the two methods are both dependent on the system parameters, but in different ways. Comparison between their sensitivities reveals that for the refraction signal, the RP method possesses a higher sensitivity, especially in the case of high visibility and/or at the edge of the object. Conclusions: Compared with the PS method, the RP method has a superior sensitivity and provides refraction images with a higher SNR. Therefore, one can obtain highly sensitive refraction images in grating-based phase contrast imaging. This is very important for future preclinical and clinical implementations.

  17. 3D CAD model retrieval method based on hierarchical multi-features

    NASA Astrophysics Data System (ADS)

    An, Ran; Wang, Qingwen

    2015-12-01

    The classical "Shape Distribution D2" algorithm takes the distance between two random points on a surface of CAD model as statistical features, and based on that it generates a feature vector to calculate the dissimilarity and achieve the retrieval goal. This algorithm has a simple principle, high computational efficiency and can get a better retrieval results for the simple shape models. Based on the analysis of D2 algorithm's shape distribution curve, this paper enhances the algorithm's descriptive ability for a model's overall shape through the statistics of the angle between two random points' normal vectors, especially for the distinctions between the model's plane features and curved surface features; meanwhile, introduce the ratio that a line between two random points cut off by the model's surface to enhance the algorithm's descriptive ability for a model's detailed features; finally, integrating the two shape describing methods with the original D2 algorithm, this paper proposes a new method based the hierarchical multi-features. Experimental results showed that this method has bigger improvements and could get a better retrieval results compared with the traditional 3D CAD model retrieval method.

  18. Methods to retrieve the complex refractive index of aquatic suspended particles: going beyond simple shapes

    NASA Astrophysics Data System (ADS)

    Sánchez, Albert-Miquel; Piera, Jaume

    2016-07-01

    The scattering properties of aquatic suspended particles have many optical applications. Several data inversion methods have been proposed to estimate important features of particles, such as their size distribution or their refractive index. Most of the proposed methods are based on the Lorenz-Mie theory to solve Maxwell's equations, where particles are considered homogeneous spheres. A generalization that allows consideration of more complex-shaped particles is the T-matrix method. Although this approach imposes some geometrical restrictions (particles must be rotationally symmetrical) it is applicable to many life forms of phytoplankton. In this paper, three different scenarios are considered in order to compare the performance of several inversion methods for retrieving refractive indices. The error associated with each method is discussed and analyzed. The results suggest that inverse methods using the T-matrix approach are useful to accurately retrieve the refractive indices of particles with complex shapes, such as for many phytoplankton organisms.

  19. [A new method for detection and erradication of Helicobacter pylori infection by stool antigens test].

    PubMed

    Amèndola, R; Doweck, J; Katz, J; Racca, J; Menendez, G; Schenone, L; Farìas, R; Barrantes, C; Quintanta, C; Zerbo, O; Kogan, Z; Valero, J; Bartellini, M A; Questa, U; Luna, P; Corti, R E

    2002-01-01

    Nowadays technics for Helicobacter pylori detection in stools like culture, and PCR, are expensive and difficult to perform. The aim of this study was to evaluate ELISA test efficacy for detection of H. Pylori antigens in stools comparing this results with standarized technics like histology (Giemsa), ureasa test and UBT C 14. 26 patients were evaluated in this study, ages between 15-75 with upper gastrointestinal symptoms; all of them required gastroduodenal endoscopy, status H. Pylori was determined with methods upon mentioned. 24 hours after endoscopy H. Pylori antigens in stools with the technique Premier Platinum Htsa, Elisa were determined. The detection of H. Pylori antigens in stools accurately identified active H. Pylori infection. The performance characteristics of this non-invasive method was similar in sensibility and specificity to conventional tests.

  20. Performance of fluorescence retrieval methods and fluorescence spectrum reconstruction under various sensor spectral configurations

    NASA Astrophysics Data System (ADS)

    Li, Rong; Zhao, Feng

    2015-10-01

    Solar-induced chlorophyll fluorescence is closely related to photosynthesis and can serve as an indicator of plant status. Several methods have been proposed to retrieve fluorescence signal (Fs) either at specific spectral bands or within the whole fluorescence emission region. In this study, we investigated the precision of the fluorescence signal obtained through these methods under various sensor spectral characteristics. Simulated datasets generated by the SCOPE (Soil Canopy Observation, Photochemistry and Energy fluxes) model with known `true' Fs as well as an experimental dataset are exploited to investigate four commonly used Fs retrieval methods, namely the original Fraunhofer Line Discriminator method (FLD), the 3 bands FLD (3FLD), the improved FLD (iFLD), and the Spectral Fitting Methods (SFMs). Fluorescence Spectrum Reconstruction (FSR) method is also investigated using simulated datasets. The sensor characteristics of spectral resolution (SR) and signal-to-noise ratio (SNR) are taken into account. According to the results, finer SR and SNR both lead to better accuracy. Lowest precision is obtained for the FLD method with strong overestimation. Some improvements are made by the 3FLD method, but it still tends to overestimate. Generally, the iFLD method and the SFMs provide better accuracy. As to FSR, the shape and magnitude of reconstructed Fs are generally consistent with the `true' Fs distributions when fine SR is exploited. With coarser SR, however, though R2 of the retrieved Fs may be high, large bias is likely to be obtained as well.

  1. A Method of Protein Model Classification and Retrieval Using Bag-of-Visual-Features

    PubMed Central

    Ma, Ziping; Kang, Baosheng; Lu, Ke

    2014-01-01

    In this paper we propose a novel visual method for protein model classification and retrieval. Different from the conventional methods, the key idea of the proposed method is to extract image features of proteins and measure the visual similarity between proteins. Firstly, the multiview images are captured by vertices and planes of a given octahedron surrounding the protein. Secondly, the local features are extracted from each image of the different views by the SURF algorithm and are vector quantized into visual words using a visual codebook. Finally, KLD is employed to calculate the similarity distance between two feature vectors. Experimental results show that the proposed method has encouraging performances for protein retrieval and categorization as shown in the comparison with other methods. PMID:25258644

  2. Assessing the impact of different satellite retrieval methods on forecast available potential energy

    NASA Technical Reports Server (NTRS)

    Whittaker, Linda M.; Horn, Lyle H.

    1990-01-01

    The effects of the inclusion of satellite temperature retrieval data, and of different satellite retrieval methods, on forecasts made with the NASA Goddard Laboratory for Atmospheres (GLA) fourth-order model were investigated using, as the parameter, the available potential energy (APE) in its isentropic form. Calculation of the APE were used to study the differences in the forecast sets both globally and in the Northern Hemisphere during 72-h forecast period. The analysis data sets used for the forecasts included one containing the NESDIS TIROS-N retrievals, the GLA retrievals using the physical inversion method, and a third, which did not contain satellite data, used as a control; two data sets, with and without satellite data, were used for verification. For all three data sets, the Northern Hemisphere values for the total APE showed an increase throughout the forecast period, mostly due to an increase in the zonal component, in contrast to the verification sets, which showed a steady level of total APE.

  3. Application of information-retrieval methods to the classification of physical data

    NASA Technical Reports Server (NTRS)

    Mamotko, Z. N.; Khorolskaya, S. K.; Shatrovskiy, L. I.

    1975-01-01

    Scientific data received from satellites are characterized as a multi-dimensional time series, whose terms are vector functions of a vector of measurement conditions. Information retrieval methods are used to construct lower dimensional samples on the basis of the condition vector, in order to obtain these data and to construct partial relations. The methods are applied to the joint Soviet-French Arkad project.

  4. A Multi-Parameter Aerosol Classification Method and its Application to Retrievals from Spaceborne Polarimetry

    NASA Astrophysics Data System (ADS)

    Russell, P. B.; Kacenelenbogen, M. S.; Livingston, J. M.; Hasekamp, O. P.; Burton, S. P.; Schuster, G. L.; Johnson, M. S.; Knobelspiesse, K. D.; Redemann, J.; Ramachandran, S.; Holben, B. N.

    2014-12-01

    Classifying observed aerosols into types (e.g., urban-industrial, biomass burning, mineral dust, maritime) helps to understand aerosol sources, transformations, effects, and feedback mechanisms; to improve accuracy of satellite retrievals; and to quantify aerosol radiative impacts on climate. The number of aerosol parameters retrieved from spaceborne sensors has been growing, from the initial aerosol optical depth (AOD) at one or a few wavelengths to a list that now includes AOD, complex refractive index, single scattering albedo (SSA), and depolarization of backscatter, each at several wavelengths, plus several particle size and shape parameters. Making optimal use of these varied data products requires objective, multi-dimensional analysis methods. We describe such a method, which makes explicit use of uncertainties in input parameters. It treats an N-parameter retrieved data point and its N-dimensional uncertainty as an extended data point, E. It then uses a modified Mahalanobis distance, DEC, to assign an observation to the class (cluster) C that has minimum DEC from the point. We use parameters retrieved from the Aerosol Robotic Network (AERONET) to define seven prespecified clusters (pure dust, polluted dust, urban-industrial/developed economy, urban-industrial/developing economy, dark biomass smoke, light biomass smoke, pure marine), and we demonstrate application of the method to a 5-year record of retrievals from the spaceborne POLDER-3 (Polarization and Directionality of the Earth's Reflectances) polarimeter over the island of Crete, Greece. Results show changes of aerosol type at this location in the eastern Mediterranean Sea, which is influenced by a wide variety of aerosol sources.

  5. A multiparameter aerosol classification method and its application to retrievals from spaceborne polarimetry

    NASA Astrophysics Data System (ADS)

    Russell, Philip B.; Kacenelenbogen, Meloë; Livingston, John M.; Hasekamp, Otto P.; Burton, Sharon P.; Schuster, Gregory L.; Johnson, Matthew S.; Knobelspiesse, Kirk D.; Redemann, Jens; Ramachandran, S.; Holben, Brent

    2014-08-01

    Classifying observed aerosols into types (e.g., urban-industrial, biomass burning, mineral dust, maritime) helps to understand aerosol sources, transformations, effects, and feedback mechanisms; to improve accuracy of satellite retrievals; and to quantify aerosol radiative impacts on climate. The number of aerosol parameters retrieved from spaceborne sensors has been growing, from the initial aerosol optical depth (AOD) at one or a few wavelengths to a list that now includes AOD, complex refractive index, single scattering albedo (SSA), and depolarization of backscatter, each at several wavelengths, plus several particle size and shape parameters. Making optimal use of these varied data products requires objective, multidimensional analysis methods. We describe such a method, which makes explicit use of uncertainties in input parameters. It treats an N-parameter retrieved data point and its N-dimensional uncertainty as an extended data point, E. It then uses a modified Mahalanobis distance, DEC, to assign an observation to the class (cluster) C that has minimum DEC from the point. We use parameters retrieved from the Aerosol Robotic Network (AERONET) to define seven prespecified clusters (pure dust, polluted dust, urban-industrial/developed economy, urban-industrial/developing economy, dark biomass smoke, light biomass smoke, and pure marine), and we demonstrate application of the method to a 5 year record of retrievals from the spaceborne Polarization and Directionality of the Earth's Reflectances 3 (POLDER 3) polarimeter over the island of Crete, Greece. Results show changes of aerosol type at this location in the eastern Mediterranean Sea, which is influenced by a wide variety of aerosol sources.

  6. [An Improved DDV Method to Retrieve AOT for HJ CCD Image in Typical Mountainous Areas].

    PubMed

    Zhao, Zhi-qiang; Li, Ai-nong; Bian, Jin-hu; Huang, Cheng-quan

    2015-06-01

    Domestic HJ CCD imaging applications in environment and disaster monitoring and prediction has great potential. But, HJ CCD image lack of Mid-Nir band can not directly retrieve Aerosol Optical Thickness (AOT) by the traditional Dark Dense Vegetation (DDV) method, and the mountain AOT changes in space-time dramatically affected by the mountain environment, which reduces the accuracy of atmospheric correction. Based on wide distribution of mountainous dark dense forest, the red band histogram threshold method was introduced to identify the mountainous DDV pixels. Subsequently, the AOT of DDV pixels were retrieved by lookup table constructed by 6S radiative transfer model with assumption of constant ratio between surface reflectance in red and blue bands, and then were interpolated to whole image. MODIS aerosol product and the retrieved AOT by the proposed algorithm had very good consistency in spatial distribution, and HJ CCD image was more suitable for the remote sensing monitoring of aerosol in mountain areas, which had higher spatial resolution. Their fitting curve of scatterplot was y = 0.828 6x-0.01 and R2 was 0.984 3 respectively. Which indicate the improved DDV method can effectively retrieve AOT, and its precision can satisfy the atmospheric correction and terrain radiation correction for Hj CCD image in mountainous areas. The improvement of traditional DDV method can effectively solve the insufficient information problem of the HJ CCD image which have only visible light and near infrared band, when solving radiative transfer equation. Meanwhile, the improved method fully considered the influence of mountainous terrain environment. It lays a solid foundation for the HJ CCD image atmospheric correction in the mountainous areas, and offers the possibility for its automated processing. In addition, the red band histogram threshold method was better than NDVI method to identify mountain DDV pixels. And, the lookup table and ratio between surface reflectance

  7. [An Improved DDV Method to Retrieve AOT for HJ CCD Image in Typical Mountainous Areas].

    PubMed

    Zhao, Zhi-qiang; Li, Ai-nong; Bian, Jin-hu; Huang, Cheng-quan

    2015-06-01

    Domestic HJ CCD imaging applications in environment and disaster monitoring and prediction has great potential. But, HJ CCD image lack of Mid-Nir band can not directly retrieve Aerosol Optical Thickness (AOT) by the traditional Dark Dense Vegetation (DDV) method, and the mountain AOT changes in space-time dramatically affected by the mountain environment, which reduces the accuracy of atmospheric correction. Based on wide distribution of mountainous dark dense forest, the red band histogram threshold method was introduced to identify the mountainous DDV pixels. Subsequently, the AOT of DDV pixels were retrieved by lookup table constructed by 6S radiative transfer model with assumption of constant ratio between surface reflectance in red and blue bands, and then were interpolated to whole image. MODIS aerosol product and the retrieved AOT by the proposed algorithm had very good consistency in spatial distribution, and HJ CCD image was more suitable for the remote sensing monitoring of aerosol in mountain areas, which had higher spatial resolution. Their fitting curve of scatterplot was y = 0.828 6x-0.01 and R2 was 0.984 3 respectively. Which indicate the improved DDV method can effectively retrieve AOT, and its precision can satisfy the atmospheric correction and terrain radiation correction for Hj CCD image in mountainous areas. The improvement of traditional DDV method can effectively solve the insufficient information problem of the HJ CCD image which have only visible light and near infrared band, when solving radiative transfer equation. Meanwhile, the improved method fully considered the influence of mountainous terrain environment. It lays a solid foundation for the HJ CCD image atmospheric correction in the mountainous areas, and offers the possibility for its automated processing. In addition, the red band histogram threshold method was better than NDVI method to identify mountain DDV pixels. And, the lookup table and ratio between surface reflectance

  8. Fresnel phase retrieval method using an annular lens array on an SLM

    NASA Astrophysics Data System (ADS)

    Loriot, V.; Mendoza-Yero, O.; Pérez-Vizcaíno, J.; Mínguez-Vega, G.; de Nalda, R.; Bañares, L.; Lancis, J.

    2014-10-01

    Wavefront aberrations play a major role when focusing an ultrashort laser pulse to a high-quality focal spot. Here, we report a novel method to measure and correct wavefront aberrations of a 30-fs pulsed laser beam. The method only requires a programmable liquid-crystal spatial light modulator and a camera. Wavefront retrieval is based on pupil segmentation with an annular lens array, which allows us to determine the local phase that minimizes focusing errors due to wavefront aberrations. Our method provides accurate results even when implemented with low dynamic range cameras and polychromatic beams. Finally, the retrieved phase is added to a diffractive lens codified onto the spatial light modulator to experimentally demonstrate near-diffraction-limited femtosecond beam focusing without refractive components.

  9. Retrieval of Aerosol information from UV measurement by using optimal estimation method

    NASA Astrophysics Data System (ADS)

    KIM, M.; Kim, J.; Jeong, U.; Kim, W. V.; Kim, S. K.; Lee, S. D.; Moon, K. J.

    2014-12-01

    An algorithm to retrieve aerosol optical depth (AOD), single scattering albedo (SSA), and aerosol loading height is developed for GEMS (Geostationary Environment Monitoring Spectrometer) measurement. The GEMS is planned to be launched in geostationary orbit in 2018, and employs hyper-spectral imaging with 0.6 nm resolution to observe solar backscatter radiation in the UV and Visible range. In the UV range, the low surface contribution to the backscattered radiation and strong interaction between aerosol absorption and molecular scattering can be advantageous in retrieving aerosol information such as AOD and SSA [Torres et al., 2007; Torres et al., 2013; Ahn et al., 2014]. However, the large contribution of atmospheric scattering results in the increase of the sensitivity of the backward radiance to aerosol loading height. Thus, the assumption of aerosol loading height becomes important issue to obtain accurate result. Accordingly, this study focused on the simultaneous retrieval of aerosol loading height with AOD and SSA by utilizing the optimal estimation method. For the RTM simulation, the aerosol optical properties were analyzed from AERONET inversion data (level 2.0) at 46 AERONET sites over ASIA. Also, 2-channel inversion method is applied to estimate a priori value of the aerosol information to solve the Lavenberg Marquardt equation. The GEMS aerosol algorithm is tested with OMI level-1B dataset, a provisional data for GEMS measurement, and the result is compared with OMI standard aerosol product and AERONET values. The retrieved AOD and SSA show reasonable distribution compared with OMI products, and are well correlated with the value measured from AERONET. However, retrieval uncertainty in aerosol loading height is relatively larger than other results.

  10. [Concentration retrieving method of SO2 using differential optical absorption spectroscopy based on statistics].

    PubMed

    Liu, Bin; Sun, Chang-Ku; Zhang, Chi; Zhao, Yu-Mei; Liu, Jun-Ping

    2011-01-01

    A concentration retrieving method using statistics is presented, which is applied in differential optical absorption spectroscopy (DOAS) for measuring the concentration of SO2. The method uses the standard deviation of the differential absorption to represents the gas concentration. Principle component analysis (PCA) method is used to process the differential absorption spectrum. In the method, the basis data for the concentration retrieval of SO2 is the combination of the PCA processing result, the correlation coefficient, and the standard deviation of the differential absorption. The method is applied to a continuous emission monitoring system (CEMS) with optical path length of 0.3 m. Its measuring range for SO2 concentration is 0-5 800 mg x m(-3). The nonlinear calibration and the temperature compensation for the system were executed. The full scale error of the retrieving concentration is less than 0.7% FS. And the measuring result is -4.54 mg x m(-3) when the concentration of SO2 is zero. PMID:21428087

  11. Method of content-based image retrieval for a spinal x-ray image database

    NASA Astrophysics Data System (ADS)

    Krainak, Daniel M.; Long, L. Rodney; Thoma, George R.

    2002-05-01

    The Lister Hill National Center for Biomedical Communications, a research and development division of the National Library of Medicine (NLM) maintains a digital archive of 17,000 cervical and lumbar spine images collected in the second National Health and Nutrition Examination Survey (NHANES II) conducted by the National Center for Health Statistics (NCHS). Classification of the images for the osteoarthritis research community has been a long-standing goal of researchers at the NLM, collaborators at NCHS, and the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS), and capability to retrieve images based on geometric characteristics of the vertebral bodies is of interest to the vertebral morphometry community. Automated or computer-assisted classification and retrieval methods are highly desirable to offset the high cost of manual classification and manipulation by medical experts. We implemented a prototype system for a database of 118 spine x-rays and health survey text data related to these x-rays. The system supports conventional text retrieval, as well as retrieval based on shape similarity to a user-supplied vertebral image or sketch.

  12. High efficient methods of content-based 3D model retrieval

    NASA Astrophysics Data System (ADS)

    Wu, Yuanhao; Tian, Ling; Li, Chenggang

    2013-03-01

    Content-based 3D model retrieval is of great help to facilitate the reuse of existing designs and to inspire designers during conceptual design. However, there is still a gap to apply it in industry due to the low time efficiency. This paper presents two new methods with high efficiency to build a Content-based 3D model retrieval system. First, an improvement is made on the "Shape Distribution (D2)" algorithm, and a new algorithm named "Quick D2" is proposed. Four sample 3D mechanical models are used in an experiment to compare the time cost of the two algorithms. The result indicates that the time cost of Quick D2 is much lower than that of D2, while the descriptors extracted by the two algorithms are almost the same. Second, an expandable 3D model repository index method with high performance, namely, RBK index, is presented. On the basis of RBK index, the search space is pruned effectively during the search process, leading to a speed up of the whole system. The factors that influence the values of the key parameters of RBK index are discussed and an experimental method to find the optimal values of the key parameters is given. Finally, "3D Searcher", a content-based 3D model retrieval system is developed. By using the methods proposed, the time cost for the system to respond one query online is reduced by 75% on average. The system has been implemented in a manufacturing enterprise, and practical query examples during a case of the automobile rear axle design are also shown. The research method presented shows a new research perspective and can effectively improve the content-based 3D model retrieval efficiency.

  13. A comparison of three retrieval methods with single Doppler radar data

    NASA Astrophysics Data System (ADS)

    Zhou, Shenghui; Wei, Ming; Gao, Li; Wang, Hao; Zeng, Qingfeng; Yang, Kun

    2011-11-01

    In single Doppler radar wind retrieval technique there are three methods proposed in recently years, which is VAP, VPP and SVVP method. Three methods were employed to retrieve wind field with the purpose to find out which one is more suitable in practice according their accuracy by using synthetic data and real data. When tests applied with uniform data, the orders of magnitude for relative error of radial velocity is 10-13 for SVVP, much lower than that of VAP and VPP which both are 10-4. Furthermore, the results under condition of wind direction unchanged and wind velocity varied linearity with altitude are 10-8, 10-3, 10-3 for SVVP, VPP and VAP, respectively. In real wind field of typhoon "Pearl", the authenticity of surrounding wind and wind shear retrieved by SVVP and VPP is better than VAP, the deviation of simulation would be increased at some points missing data. Relative errors of radial velocity achieved by VAP, VPP and SVVP are 7.02, 5.78 and 3.1 respectively. It indicated that SVVP method's performance is better than that of other two and suitable in practical applications.

  14. System and method for phase retrieval for radio telescope and antenna control

    NASA Technical Reports Server (NTRS)

    Dean, Bruce H. (Inventor)

    2013-01-01

    Disclosed herein are systems, methods, and non-transitory computer-readable storage media for radio phase retrieval. A system practicing the method gathers first data from radio waves associated with an object observed via a first aperture, gathers second data from radio waves associated with the object observed via an introduced second aperture associated with the first aperture, generates reduced noise data by incoherently subtracting the second data from the first data, and performs phase retrieval for the radio waves by modeling the reduced noise data using a single Fourier transform. The first and second apertures are at different positions, such as side by side. This approach can include determining a value Q which represents a ratio of wavelength times a focal ratio divided by pixel spacing. This information can be used to accurately measure and correct alignment errors or other optical system flaws in the apertures.

  15. Methods of semen collection not based on masturbation or surgical sperm retrieval.

    PubMed

    Gerris, J

    1999-01-01

    Although masturbation is the standard method for the collection of a sperm sample, both for diagnostic and therapeutic purposes, other approaches have been described and assessed. Production of semen using specially designed condoms has been shown to result in samples with better laboratory characteristics than samples obtained after masturbation or coitus interruptus. However, this has not resulted in a general acceptance and use of this approach, except in special circumstances where masturbation is impossible or unacceptable. Direct retrieval of spermatozoa from morning urine is another method which has been used to study spermache in boys, but not to treat infertility. Sperm production techniques such as vibro- and electrostimulation are dealt with elsewhere, as are surgical retrieval techniques used in azoospermia.

  16. Ptychographic phase retrieval method for characterizing ultra-precise ellipsoidal mirrors

    NASA Astrophysics Data System (ADS)

    Takeo, Yoko; Saito, Takahiro; Mimura, Hidekazu

    2015-10-01

    Focusing and imaging optics can be characterized by evaluating the wavefront error of the focused beam. We have bean developing a ptychographic phase retrieval method using a visible laser to measure the wavefront error. In this study, the measurement accuracy of the method is increased by improving both the phase retrieval algorithm and the experimental setup. The system is applied to the characterization of an ellipsoidal mirror used for the focusing of soft X-rays. The posture of the mirror can be measured with a resolution of 1.4 μrad. The wavefront error originating from the surface profile error can be detected with an accuracy of 0.01λ (root mean square).

  17. The Influence of Learning Methods on Collaboration: Prior Repeated Retrieval Enhances Retrieval Organization, Abolishes Collaborative Inhibition, and Promotes Post-Collaborative Memory

    ERIC Educational Resources Information Center

    Congleton, Adam R.; Rajaram, Suparna

    2011-01-01

    Research on collaborative memory has unveiled the counterintuitive yet robust phenomenon that collaboration impairs group recall. A candidate explanation for this "collaborative inhibition" effect is the disruption of people's idiosyncratic retrieval strategies during collaboration, and it is hypothesized that employing methods that improve one's…

  18. Advanced retrieval method in satellite remote sensing atmosphere: the technique of computed tomography

    NASA Astrophysics Data System (ADS)

    Zhang, Jun; Xun, Yulong

    1998-08-01

    Computed Tomography (CT) is a modern medical diagnostic technique in which x-ray transmission measurements at numerous angles through the human body are processed by computer to produce cross-sectional pictures of the body. This technique also has found applications in such diverse fields as materials testing, astronomy, microscopy, image processing and oceanography.In this paper, a modification of this technique, using emitted IR or microwave radiation instead of transmitted x-ray radiation, can be applied to satellite radiance measurements taken along the orbital track at various angles. The channels of IR sensors for the CT retrieval are selected from HITRAN Database, and analyzed by Eigen-value analysis. We discuss in detail the effect retrieval result of CT technique form projection-angle. Finally, using the balloon sounding data, the result of CT are compared with the result of conventional method. Because the advantage over conventional remote sensing methods is the additional information acquired by viewing a given point in the atmosphere at several angles as well as several frequencies. The results show that the temperature profiles by CT retrieval are better than the conventional method.

  19. Comparison of Ozone Profiles Retrieved With Different Methods From Odin/osiris Limb Spectra

    NASA Astrophysics Data System (ADS)

    Haley, C. S.; von Savigny, C.; Auvinen, H.; Griffioen, E.; Hassinen, S.; Kyrölä, E.; McDade, I. C.; Oikarinen, L.; Siiskonen, T.; Sioris, C. E.

    The Swedish/Canadian/Finnish/French Odin satellite was launched on 20 February 2001 carrying the Optical Spectrograph and InfraRed Imager System (OSIRIS). The optical spectrograph measures the spectrum of sunlight scattered by the limb of the atmosphere in the spectral range 280 nm to 800 nm at a resolution of about 1 nm. The scattered sunlight spectra are used to determine vertical profiles of minor stratospheric constituents such as ozone, NO2, OClO, BrO and aerosols. Stratospheric ozone profiles are retrieved from OSIRIS measurements using three dif- ferent techniques: Modified Onion Peeling (MOP) (Auvinen et al., JGR, in press, 2001), Differential Optical Absorption Spectroscopy (DOAS), and a method based on the analysis of normalized and paired limb-radiance profiles (Flittner et al., GRL 27, 2601, 2000). All of the techniques incorporate the pseudo-spherical multiple scat- tering radiative transfer model LIMBTRAN. In this paper we compare results of the different retrieval methods for measurements during Northern Hemisphere summer and Antarctic ozone hole conditions. We find that all of the methods are able to re- cover the major features of the global morphology of stratospheric ozone. We also compare the retrievals with POAM III and EP-TOMS measurements and find good agreement.

  20. Influenza virus titration, antigenic characterization, and serological methods for antibody detection.

    PubMed

    Klimov, Alexander; Balish, Amanda; Veguilla, Vic; Sun, Hong; Schiffer, Jarad; Lu, Xiuhua; Katz, Jacqueline M; Hancock, Kathy

    2012-01-01

    This chapter describes some commonly used methods of influenza virus titration, antigenic characterization, and serological methods by antibody detection. These methods are essential not only for virus characterization but also for identifying new antigenic variants, vaccine strain selection, and sero-epidemiologic studies of influenza virus transmission and prevalence. Virus titration methods such as the hemagglutination assay, 50% egg or tissue culture infectious dose, and plaque assay are employed to determine the amount of virus particles in a sample. The hemagglutination inhibition assay is a reliable, relatively simple and inexpensive technique to antigenically characterize isolates of influenza viruses. Serological methods such as virus neutralization and hemagglutination inhibition are the fundamental tools used in sero-epidemiologic studies of influenza virus transmission and prevalence and in the evaluation of vaccine immunogenicity. While serological methods rarely yield an early diagnosis of acute influenza virus infection, well-timed, paired acute, and convalescent serum samples may establish the diagnosis of a recent influenza infection even when attempts to detect the virus are negative.

  1. Development and application of new methods to retrieve vertical structure of precipitation above the ARM CART sites from MMCR measurements

    SciTech Connect

    Matrosov, Sergey

    2010-12-15

    The main objective of this project was to develop, validate and apply remote sensing methods to retrieve vertical profiles of precipitation over the DOE ARM CART sites using currently available remote sensors. While the ARM Program invested very heavily into developments of remote sensing methods and instruments for water vapor and non-precipitating cloud parameter retrievals, precipitation retrievals and studies lagged behind. Precipitation, however, is a crucial part of the water cycle, and without detailed information on rainfall and snowfall, significant improvements in the atmospheric models of different scales (i.e., one of the ARM Program's main goals) is difficult to achieve. Characterization of the vertical atmospheric column above the CART sites is also incomplete without detailed precipitation information, so developments of remote sensing methods for retrievals of parameters in precipitating cloud condition was essential. Providing modelers with retrieval results was also one of the key objectives of this research project.

  2. One of the Methods of Organizing the Information Storage Unit of a System of Data Retrieval and Processing (SPOD).

    ERIC Educational Resources Information Center

    Askinazi, R. B.; Papina, I. L.

    The paper deals with one method of organizing the storage unit of a descriptor IPS (information retrieval system) of the SPOD type, the information array of which constitutes the totality of uniform documents with ordered disposition of data within each of them. Three categories of data composing the retrieval form of document were defined…

  3. The Mnemonic Keyword Method: The Effects of Bidirectional Retrieval Training and of Ability to Image on Foreign Language Vocabulary Recall

    ERIC Educational Resources Information Center

    Wyra, Mirella; Lawson, Michael J.; Hungi, Njora

    2007-01-01

    The mnemonic keyword method is an effective technique for vocabulary acquisition. This study examines the effects on recall of word-meaning pairs of (a) training in use of the keyword procedure at the time of retrieval; and (b) the influence of the self-rated ability to image. The performance of students trained in bidirectional retrieval using…

  4. Retrieval of Vertical Ozone Profile Using Satellite Solar Occultation Method and Tests of its Sensitivity

    NASA Astrophysics Data System (ADS)

    Cho, Hi-Ku; Yoon, Young-Jun; Park, Jae H.; Lee, Kwang Mok; Tatsuya, Yokota

    1998-06-01

    Recently measurements of atmospheric trace gases from satellite are vigorous. So the development of its data processing algorithm is important. In this study, retrieval of vertical ozone profile from the atmospheric transmittance measured by satellite solar occultation method and its sensitivity to temperature and pressure are investigated. The measured transmittance from satellite is assumed to be given by the limb path transmittance simulated using annual averaged Umkehr data for Seoul. The limb path transmittance between wavelengths 9.89micro m and 10.02micro m is simulated with respect to tangent heights using the ozone data of HALOE SIDS(Hallogen Occultation Experiment Simulated Instrument Data Set) as an initial profile. Other input data such as pressure and temperature are also from HALOE SIDS. Vertical ozone profile is correctly retrieved from the measured transmittance by onion-peeling method from 50km to 11km tangent heights with the vertical resolution of 3km. The bias error of +/- 0.001 in measured transmittance, the forced error of +/- 3K in each layer temperature, and the forced +/- 3% error in each layer pressure are assumed for sensitivity tests. These errors are based on the ADEOS/ILAS error limitation. The error in ozone amount ranges from -6.5% to +6.9% due to transmittance error, from -9.5% to +10.5% due to temperature error, and from -5.1% to +5.4% due to pressure error, respectively. The present study suggests that accurate vertical ozone profile can be retrieved from satellite solar occultation method. Accuracy of vertical temperature profile is especially important in the retrieval of vertical ozone profile.

  5. [Subunit vaccines--antigens, carriers, conjugation methods and the role of adjuvants].

    PubMed

    Jarząb, Anna; Skowicki, Michał; Witkowska, Danuta

    2013-11-27

    Vaccines are effective tools protecting against the development of infectious diseases caused by pathogenic microorganisms. Currently, we have vaccines protecting against many infections, where standard therapy is not only difficult but often impossible due to the ever-progressive increase in bacterial resistance to many available antibiotics. Among vaccines which have been used in the prevention of infection are the traditional vaccines containing live, killed or attenuated strains of microorganisms. However, it should be noted that such vaccines are not always effective, especially when the expected immune response is directed against specific antigens. Subunit vaccines belong to new generation vaccines and have gained more and more interest in recent years. These vaccines contain fragments of pathogenic microorganisms, which are highly purified and immunogenic antigens. Using these purified antigens excludes the risk of post-vaccination infection. In addition, subunit vaccines minimize side-effects associated with the use of whole bacterial cells. The paper discusses the most promising and the most tested antigens, vaccine carriers, conjugation methods and vaccine delivery systems which are being used in the design of subunit vaccines. This paper also highlights the advantages and disadvantages of adjuvants, which are substances to support the immune response in humans, and the relationship between adjuvants' efficacy and their mechanism of action.

  6. An incremental DPMM-based method for trajectory clustering, modeling, and retrieval.

    PubMed

    Hu, Weiming; Li, Xi; Tian, Guodong; Maybank, Stephen; Zhang, Zhongfei

    2013-05-01

    Trajectory analysis is the basis for many applications, such as indexing of motion events in videos, activity recognition, and surveillance. In this paper, the Dirichlet process mixture model (DPMM) is applied to trajectory clustering, modeling, and retrieval. We propose an incremental version of a DPMM-based clustering algorithm and apply it to cluster trajectories. An appropriate number of trajectory clusters is determined automatically. When trajectories belonging to new clusters arrive, the new clusters can be identified online and added to the model without any retraining using the previous data. A time-sensitive Dirichlet process mixture model (tDPMM) is applied to each trajectory cluster for learning the trajectory pattern which represents the time-series characteristics of the trajectories in the cluster. Then, a parameterized index is constructed for each cluster. A novel likelihood estimation algorithm for the tDPMM is proposed, and a trajectory-based video retrieval model is developed. The tDPMM-based probabilistic matching method and the DPMM-based model growing method are combined to make the retrieval model scalable and adaptable. Experimental comparisons with state-of-the-art algorithms demonstrate the effectiveness of our algorithm. PMID:23520251

  7. A comparison of dimensionality reduction methods for retrieval of similar objects in simulation data

    SciTech Connect

    Cantu-Paz, E; Cheung, S S; Kamath, C

    2003-09-23

    High-resolution computer simulations produce large volumes of data. As a first step in the analysis of these data, supervised machine learning techniques can be used to retrieve objects similar to a query that the user finds interesting. These objects may be characterized by a large number of features, some of which may be redundant or irrelevant to the similarity retrieval problem. This paper presents a comparison of six dimensionality reduction algorithms on data from a fluid mixing simulation. The objective is to identify methods that efficiently find feature subsets that result in high accuracy rates. Our experimental results with single- and multi-resolution data suggest that standard forward feature selection produces the smallest feature subsets in the shortest time.

  8. Note: Phase retrieval method for analyzing single-phase displacement interferometry data

    SciTech Connect

    Chen, X. H.; Zeng, X. L.; Fan, D.; Liu, Q. C.; Bie, B. X.; Zhou, X. M. Luo, S. N.

    2014-02-15

    We present a phase retrieval method (PRM) for analyzing single-phase displacement interferometry measurements on rapidly changing velocity histories, including photon Doppler velocimetry (PDV). PRM identifies the peaks and valleys as well as zero-crossing points in a PDV time series, performs normalization and extracts point-by-point phase and thus velocity information. PRM does not require a wide time window as in sliding window Fourier transformation, and thus improves the effective temporal resolution. This method is implemented in analyzing PDV data obtained from gas gun experiments, and validated against simultaneous measurements with velocity interferometer system for any reflector.

  9. Note: phase retrieval method for analyzing single-phase displacement interferometry data.

    PubMed

    Chen, X H; Zeng, X L; Fan, D; Liu, Q C; Bie, B X; Zhou, X M; Luo, S N

    2014-02-01

    We present a phase retrieval method (PRM) for analyzing single-phase displacement interferometry measurements on rapidly changing velocity histories, including photon Doppler velocimetry (PDV). PRM identifies the peaks and valleys as well as zero-crossing points in a PDV time series, performs normalization and extracts point-by-point phase and thus velocity information. PRM does not require a wide time window as in sliding window Fourier transformation, and thus improves the effective temporal resolution. This method is implemented in analyzing PDV data obtained from gas gun experiments, and validated against simultaneous measurements with velocity interferometer system for any reflector.

  10. Method for Retrieving Leaf Biochemical Parameters from Hyperspectral Remote Sensing Data

    NASA Astrophysics Data System (ADS)

    Chen, J. M.; Li, Y.; Zhang, Y.

    2002-05-01

    Retrieving biophysical and biochemical parameters is one of the most important and promising applications of hyperspectral remote sensing and will contribute greatly to the understanding of terrestrial ecosystems. We developed a mathematical inversion method for deriving leaf chlorophyll and water contents, which are potentially very useful as inputs to photosynthesis and carbon cycle models. From hyperspectral data cubes, global absorption coefficients for these parameters have been derived from two leaf spectral models named LIBERTY and PROSPECT. Taking into account the various factors affecting the coefficients such as the cellular structure of leaves and concentrations of other substances (lignin, protein, etc.), we have successfully retrieved chlorophyll and water concentrations of leaves. The inversion model is tested by comparing these parameters used in the forward calculations of leaf spectra and the same parameters retrieved from these forward-calculated spectra. Excellent agreement is found between the inverse and forward results, the difference being generally less than 1%. Atmospherically corrected airborne hyperspectral CASI (Compact Airborne Spectrographic Imager) images over a boreal forest are chosen for further model test. Through the model inversion, the data cube with 72 spectral bands and 405x2852 pixels is used to produce maps of the chlorophyll and water concentrations for the forest. The influence of canopy architecture on the inversion results is yet to be investigated using a geometrical optical model.

  11. Developments of global greenhouse gas retrieval algorithm based on Optimal Estimation Method

    NASA Astrophysics Data System (ADS)

    Kim, W. V.; Kim, J.; Lee, H.; Jung, Y.; Boesch, H.

    2013-12-01

    After the industrial revolution, atmospheric carbon dioxide concentration increased drastically over the last 250 years. It is still increasing and over than 400ppm of carbon dioxide was measured at Mauna Loa observatory for the first time which value was considered as important milestone. Therefore, understanding the source, emission, transport and sink of global carbon dioxide is unprecedentedly important. Currently, Total Carbon Column Observing Network (TCCON) is operated to observe CO2 concentration by ground base instruments. However, the number of site is very few and concentrated to Europe and North America. Remote sensing of CO2 could supplement those limitations. Greenhouse Gases Observing SATellite (GOSAT) which was launched 2009 is measuring column density of CO2 and other satellites are planned to launch in a few years. GOSAT provide valuable measurement data but its low spatial resolution and poor success rate of retrieval due to aerosol and cloud, forced the results to cover less than half of the whole globe. To improve data availability, accurate aerosol information is necessary, especially for East Asia region where the aerosol concentration is higher than other region. For the first step, we are developing CO2 retrieval algorithm based on optimal estimation method with VLIDORT the vector discrete ordinate radiative transfer model. Proto type algorithm, developed from various combinations of state vectors to find best combination of state vectors, shows appropriate result and good agreement with TCCON measurements. To reduce calculation cost low-stream interpolation is applied for model simulation and the simulation time is drastically reduced. For the further study, GOSAT CO2 retrieval algorithm will be combined with accurate GOSAT-CAI aerosol retrieval algorithm to obtain more accurate result especially for East Asia.

  12. Analysis of sperm antigens by sodium dodecyl sulfate gel/protein blot radioimmunobinding method

    SciTech Connect

    Lee, C.Y.G.; Huang, Y.S.; Hu, P.C.; Gomel, V.; Menge, A.C.

    1982-06-01

    A radioimmunobinding method based on the blotting of renatured proteins from sodium dodecyl sulfate gels on to nitrocellulose filter papers was developed to analyze the sperm antigens that elicit serum anti-sperm antibodies. In rabbits, serum anti-sperm antibodies were raised by immunization with homologous epididymal spermatozoa mixed with complete Freund's adjuvant. The raised antisera from either male or female rabbits were shown to react with three major sperm protein bands on sodium dodecyl sulfate gels with the corresponding molecular weights of about 70,000 +/- 5000, 14,000, and 13,000, respectively. In humans, the monoclonal antibodies against human sperm were raised by a hybridoma technique. Out of six independent hybrid cell lines that were generated, three of them were shown to secrete immunoglobulins that react with the same two protein bands on sodium dodecyl sulfate gels, which have the approximate molecular weight of 10,000. The same procedure was also used to analyze human serum samples that were shown to contain anti-sperm antibodies by the known techniques. Unique sperm antigens that elicit anti-sperm antibodies in humans were identified and correlated. The results of this study suggest that sodium dodecyl sulfate gel/protein blot radioimmunobinding method may be a sensitive and useful tool for the study of sperm antigens that elicit autoimmune responses and their association with human infertility.

  13. Phase retrieval in annulus sector domain by non-iterative methods

    NASA Astrophysics Data System (ADS)

    Wang, Xiao; Mao, Heng; Zhao, Da-zun

    2008-03-01

    Phase retrieval could be achieved by solving the intensity transport equation (ITE) under the paraxial approximation. For the case of uniform illumination, Neumann boundary condition is involved and it makes the solving process more complicated. The primary mirror is usually designed segmented in the telescope with large aperture, and the shape of a segmented piece is often like an annulus sector. Accordingly, It is necessary to analyze the phase retrieval in the annulus sector domain. Two non-iterative methods are considered for recovering the phase. The matrix method is based on the decomposition of the solution into a series of orthogonalized polynomials, while the frequency filtering method depends on the inverse computation process of ITE. By the simulation, it is found that both methods can eliminate the effect of Neumann boundary condition, save a lot of computation time and recover the distorted phase well. The wavefront error (WFE) RMS can be less than 0.05 wavelength, even when some noise is added.

  14. Retrieval of terahertz spectroscopic signatures in the presence of rough surface scattering using wavelet methods

    NASA Astrophysics Data System (ADS)

    Arbab, M. H.; Winebrenner, D. P.; Thorsos, E. I.; Chen, A.

    2010-11-01

    Scattering of terahertz waves by surface roughness can obscure spectral signatures of chemicals at these frequencies. We demonstrate this effect using controlled levels of surface scattering on α-lactose monohydrate pellets. Furthermore, we show an implementation of wavelet methods that can retrieve terahertz spectral information from rough surface targets. We use a multiresolution analysis of the rough-surface-scattered signal utilizing the maximal overlap discrete wavelet transform (MODWT) to extract the resonant signature of lactose. We present a periodic extension technique to circumvent the circular boundary conditions of MODWT, which can be robustly used in an automated terahertz stand-off detection device.

  15. Pulse retrieval in frequency-resolved optical gating based on the method of generalized projections

    SciTech Connect

    DeLong, K.W.; Fittinghoff, D.N.; Trebino, R. ); Kohler, B.; Wilson, K. )

    1994-12-15

    We use the algorithmic method of generalized projections (GP's) to retrieve the intensity and phase of an ultrashort laser pulse from the experimental trace in frequency-resolved optical gating (FROG). Using simulations, we show that the use of GP's improves significantly the convergence properties of the algorithm over the basic FROG algorithm. In experimental measurements, the GP-based algorithm achieves significantly lower errors than previous algorithms. The use of GP's also permits the inclusion of an arbitrary material response function in the FROG problem.

  16. Immunohistochemical retrieval of the principal HIV antigens p24, gp41, and gp120 in formalin fixed tissue: an investigation using HIV infected lymphoblasts and postmortem brain tissue from AIDS cases.

    PubMed Central

    Morrison, H L; Neal, J W; Parkes, A B; Jasani, B

    1998-01-01

    This paper describes the use of an autoclaving procedure followed by immunocytochemistry to enhance the detection of the human immunodeficiency virus (HIV) antigens p24, gp41, and gp120. This procedure greatly improved the detection rate of the p24 and gp41 HIV surface antigens in formalin fixed, paraffin wax embedded, HIV positive central nervous system (CNS) tissue while restricting staining to areas of the CNS showing evidence of neuropathology. However, the technique did not improve retrieval of the gp120 antigen in either HIV positive, formalin fixed CNS tissue or HIV infected T lymphoblasts. The inclusion of the high temperature autoclave step was validated using both HIV infected lymphoblasts and pre-adsorption of the specific antibodies with the appropriate recombinant HIV proteins. Using the methodology described here, formalin fixed CNS tissue from potential or known HIV positive cases can be processed reliably and safely. To ensure the reliability of this technique, it is recommended that an assessment of both the p24 and gp41 antigens is undertaken. PMID:9893752

  17. A nonlinear spectral unmixing method for abundance retrieval of mineral mixtures

    NASA Astrophysics Data System (ADS)

    Zhang, Xia; Lin, Honglei; Cen, Yi; Yang, Hang

    2016-05-01

    Minerals are generally present as intimate mixtures. The spectra of intimate mixtures in visible-infrared are complex function of abundance, grain size, and optical constants et.al, making the linear spectral unmixing model inapplicable. In this paper, we presented a nonlinear unmixing method by combining Shkuratov model (SK99) and Hapke model (H81) to unmix the mineral mixtures. For obtaining the abundances of mineral endmembers, we built up a look-up table (LUT) in the following steps: First, the optical constants were derived by SK99 model and then single scattering albedos of endmembers were computed. Second, the approximation of multiple scattering was derived by the Chandrasekhar H-function. Finally, LUT was established using H81 model. The root-mean-square error (RMSE) was calculated to find the best match between the reflectance of mixtures and LUT. We used the laboratory mineral mixtures to verify the accuracy of abundance estimation. The results show that RMSEs are less than 1% and the absolute errors of abundance retrieval are within 5%. The presented method can retrieve mineral abundance effectively and rapidly. It can be a potential method applying for hyperspectral images of the earth and planetary.

  18. An online aerosol retrieval algorithm using OMI near-UV observations based on the optimal estimation method

    NASA Astrophysics Data System (ADS)

    Jeong, U.; Kim, J.; Ahn, C.; Torres, O.; Liu, X.; Bhartia, P. K.; Spurr, R. J. D.; Haffner, D.; Chance, K.; Holben, B. N.

    2015-06-01

    An online version of the OMI (Ozone Monitoring Instrument) near-ultraviolet (UV) aerosol retrieval algorithm was developed to retrieve aerosol optical thickness (AOT) and single scattering albedo (SSA) based on the optimal estimation (OE) method. Instead of using the traditional look-up tables for radiative transfer calculations, it performs online radiative transfer calculations with the Vector Linearized Discrete Ordinate Radiative Transfer (VLIDORT) model to eliminate interpolation errors and improve stability. The OE-based algorithm has the merit of providing useful estimates of uncertainties simultaneously with the inversion products. The measurements and inversion products of the Distributed Regional Aerosol Gridded Observation Network campaign in Northeast Asia (DRAGON NE-Asia 2012) were used to validate the retrieved AOT and SSA. The retrieved AOT and SSA at 388 nm have a correlation with the Aerosol Robotic Network (AERONET) products that is comparable to or better than the correlation with the operational product during the campaign. The estimated retrieval noise and smoothing error perform well in representing the envelope curve of actual biases of AOT at 388 nm between the retrieved AOT and AERONET measurements. The forward model parameter errors were analyzed separately for both AOT and SSA retrievals. The surface albedo at 388 nm, the imaginary part of the refractive index at 354 nm, and the number fine mode fraction (FMF) were found to be the most important parameters affecting the retrieval accuracy of AOT, while FMF was the most important parameter for the SSA retrieval. The additional information provided with the retrievals, including the estimated error and degrees of freedom, is expected to be valuable for future studies.

  19. Popliteal lymph node assay as a method of investigating H-Y antigen in the rat.

    PubMed

    Markwick, J R; Pegrum, G D

    1981-03-01

    The ability of the popliteal lymph node assay (PLNA) To detect host-versus-graft activity in response to H-Y antigens was investigated in the rat by using presensitized recipients. It was shown that significant popliteal lymph node (PLN) enlargement in response to H-Y-incompatible lymphocytes from syngeneic donors could be obtained in female recipients that had been preimmunized by the weekly i.p. injection of 1 x 10(7) lymphocytes from males of the same strain. In one rat strain, it was also shown that when male recipients had been similarly preimmunized with lymphocytes from females of the same strain, significant PLN enlargement could be obtained in response to lymphocytes from syngeneic females. The results that we obtained using the PLNA are discussed in comparison with those that have been reported when H-Y-incompatible skin grafts have been used to investigate H-Y antigen in the rat. These results indicate that, in the rat, the PLNA provides a useful alternative method for the investigation of H-Y antigen and may also provide a useful means to investigate the response of male rats to lymphocytes from syngeneic females.

  20. Evaluation of RNA Amplification Methods to Improve DC Immunotherapy Antigen Presentation and Immune Response

    PubMed Central

    Slagter-Jäger, Jacoba G; Raney, Alexa; Lewis, Whitney E; DeBenedette, Mark A; Nicolette, Charles A; Tcherepanova, Irina Y

    2013-01-01

    Dendritic cells (DCs) transfected with total amplified tumor cell RNA have the potential to induce broad antitumor immune responses. However, analytical methods required for quantitatively assessing the integrity, fidelity, and functionality of the amplified RNA are lacking. We have developed a series of assays including gel electrophoresis, northern blot, capping efficiency, and microarray analysis to determine integrity and fidelity and a model system to assess functionality after transfection into human DCs. We employed these tools to demonstrate that modifications to our previously reported total cellular RNA amplification process including the use of the Fast Start High Fidelity (FSHF) PCR enzyme, T7 Powerswitch primer, post-transcriptional capping and incorporation of a type 1 cap result in amplification of longer transcripts, greater translational competence, and a higher fidelity representation of the starting total RNA population. To study the properties of amplified RNA after transfection into human DCs, we measured protein expression levels of defined antigens coamplified with the starting total RNA populations and measured antigen-specific T cell expansion in autologous DC-T cell co-cultured in vitro. We conclude from these analyses that the improved RNA amplification process results in superior protein expression levels and a greater capacity of the transfected DCs to induce multifunctional antigen-specific memory T cells. PMID:23653155

  1. Application of an enzyme-labeled antigen method for visualizing plasma cells producing antibodies against Strep A, a carbohydrate antigen of Streptococcus pyogenes, in recurrent tonsillitis.

    PubMed

    Onouchi, Takanori; Mizutani, Yasuyoshi; Shiogama, Kazuya; Inada, Ken-ichi; Okada, Tatsuyoshi; Naito, Kensei; Tsutsumi, Yutaka

    2015-01-01

    Streptococcus pyogenes is the main causative pathogen of recurrent tonsillitis. Histologically, lesions of recurrent tonsillitis contain numerous plasma cells. Strep A is an antigenic carbohydrate molecule on the cell wall of S. pyogenes. As expected, plasma cells in subjects with recurrent tonsillitis secrete antibodies against Strep A. The enzyme-labeled antigen method is a novel histochemical technique that visualizes specific antibody-producing cells in tissue sections by employing a biotin-labeled antigen as a probe. The purpose of the present study was to visualize plasma cells producing antibodies reactive with Strep A in recurrent tonsillitis. Firstly, the lymph nodes of rats immunized with boiled S. pyogenes were paraformaldehyde-fixed and specific plasma cells localized in frozen sections with biotinylated Strep A. Secondly, an enzyme-labeled antigen method was used on human tonsil surgically removed from 12 patients with recurrent tonsillitis. S. pyogenes genomes were PCR-detected in all 12 specimens. The emm genotypes belonged to emm12 in nine specimens and emm1 in three. Plasma cells producing anti-Strep A antibodies were demonstrated in prefixed frozen sections of rat lymph nodes, 8/12 human specimens from patients with recurrent tonsillitis but not in two control tonsils. In human tonsils, Strep A-reactive plasma cells were observed within the reticular squamous mucosa and just below the mucosa, and the specific antibodies belonged to either IgA or IgG classes. Our technique is effective in visualizing immunocytes producing specific antibodies against the bacterial carbohydrate antigen, and is thus a novel histochemical tool for analyzing immune reactions in infectious disorders.

  2. Inverse problem of the multislice method in retrieving projected complex potentials from the exit-wave function.

    PubMed

    Lin, Fang; Jin, Chuanhong

    2014-03-01

    We proposed a new algorithm that retrieves the projected potentials from the EW of object. This algorithm is based on the traditional multislice method which involves the convolution operation in calculation. The retrieved potential is complex including both the electrostatic and absorptive components. Tests with the simulated exit waves of a 200 K InP crystal prove the algorithm effective for objects in wide thickness range. For thick specimen where dynamical electron diffraction prevails, the retrieved potential could present structure and chemical information of object by completely mapping an atom's scattering potential during interaction with incident electrons. PMID:24361232

  3. A Novel Medical Freehand Sketch 3D Model Retrieval Method by Dimensionality Reduction and Feature Vector Transformation

    PubMed Central

    Jing, Zhang; Sheng, Kang Bao

    2016-01-01

    To assist physicians to quickly find the required 3D model from the mass medical model, we propose a novel retrieval method, called DRFVT, which combines the characteristics of dimensionality reduction (DR) and feature vector transformation (FVT) method. The DR method reduces the dimensionality of feature vector; only the top M low frequency Discrete Fourier Transform coefficients are retained. The FVT method does the transformation of the original feature vector and generates a new feature vector to solve the problem of noise sensitivity. The experiment results demonstrate that the DRFVT method achieves more effective and efficient retrieval results than other proposed methods. PMID:27293478

  4. Evaluation of shape indexing methods for content-based retrieval of x-ray images

    NASA Astrophysics Data System (ADS)

    Antani, Sameer; Long, L. Rodney; Thoma, George R.; Lee, Dah-Jye

    2003-01-01

    Efficient content-based image retrieval of biomedical images is a challenging problem of growing research interest. Feature representation algorithms used in indexing medical images on the pathology of interest have to address conflicting goals of reducing feature dimensionality while retaining important and often subtle biomedical features. At the Lister Hill National Center for Biomedical Communications, a R&D division of the National Library of Medicine, we are developing a content-based image retrieval system for digitized images of a collection of 17,000 cervical and lumbar x-rays taken as a part of the second National Health and Nutrition Examination Survey (NHANES II). Shape is the only feature that effectively describes various pathologies identified by medical experts as being consistently and reliably found in the image collection. In order to determine if the state of the art in shape representation methods is suitable for this application, we have evaluated representative algorithms selected from the literature. The algorithms were tested on a subset of 250 vertebral shapes. In this paper we present the requirements of an ideal algorithm, define the evaluation criteria, and present the results and our analysis of the evaluation. We observe that while the shape methods perform well on visual inspection of the overall shape boundaries, they fall short in meeting the needs of determining similarity between the vertebral shapes based on the pathology.

  5. Costs and benefits in item-method directed forgetting: differential effects of encoding and retrieval.

    PubMed

    Lee, Yuh-Shiow

    2013-01-01

    This study examined how encoding and retrieval factors affected directed forgetting costs and benefits in an item-method procedure. Experiment 1 used a typical item-method procedure and revealed a levels-of-processing effect in overall recall. However, the deep encoding condition showed a smaller directed forgetting effect than the shallow encoding conditions. More importantly, "remember" (R) words were selectively rehearsed as indicated by greater recall from the primacy portion of the list and more apt to be recalled before "forget" (F) words. Experiment 2 showed that a deep encoding operation reduced directed forgetting costs and that directed forgetting benefits occurred only when R words were recalled before F words. These findings supported the hypotheses that encoding manipulation affected directed forgetting costs and that directed forgetting benefits were associated with output order bias. Results were discussed in terms of mechanisms that produce item-method directed forgetting.

  6. A fast image retrieval method based on SVM and imbalanced samples in filtering multimedia message spam

    NASA Astrophysics Data System (ADS)

    Chen, Zhang; Peng, Zhenming; Peng, Lingbing; Liao, Dongyi; He, Xin

    2011-11-01

    With the swift and violent development of the Multimedia Messaging Service (MMS), it becomes an urgent task to filter the Multimedia Message (MM) spam effectively in real-time. For the fact that most MMs contain images or videos, a method based on retrieving images is given in this paper for filtering MM spam. The detection method used in this paper is a combination of skin-color detection, texture detection, and face detection, and the classifier for this imbalanced problem is a very fast multi-classification combining Support vector machine (SVM) with unilateral binary decision tree. The experiments on 3 test sets show that the proposed method is effective, with the interception rate up to 60% and the average detection time for each image less than 1 second.

  7. Experimental Sentinel-2 LAI estimation using parametric, non-parametric and physical retrieval methods - A comparison

    NASA Astrophysics Data System (ADS)

    Verrelst, Jochem; Rivera, Juan Pablo; Veroustraete, Frank; Muñoz-Marí, Jordi; Clevers, Jan G. P. W.; Camps-Valls, Gustau; Moreno, José

    2015-10-01

    Given the forthcoming availability of Sentinel-2 (S2) images, this paper provides a systematic comparison of retrieval accuracy and processing speed of a multitude of parametric, non-parametric and physically-based retrieval methods using simulated S2 data. An experimental field dataset (SPARC), collected at the agricultural site of Barrax (Spain), was used to evaluate different retrieval methods on their ability to estimate leaf area index (LAI). With regard to parametric methods, all possible band combinations for several two-band and three-band index formulations and a linear regression fitting function have been evaluated. From a set of over ten thousand indices evaluated, the best performing one was an optimized three-band combination according to (ρ560 -ρ1610 -ρ2190) / (ρ560 +ρ1610 +ρ2190) with a 10-fold cross-validation RCV2 of 0.82 (RMSECV : 0.62). This family of methods excel for their fast processing speed, e.g., 0.05 s to calibrate and validate the regression function, and 3.8 s to map a simulated S2 image. With regard to non-parametric methods, 11 machine learning regression algorithms (MLRAs) have been evaluated. This methodological family has the advantage of making use of the full optical spectrum as well as flexible, nonlinear fitting. Particularly kernel-based MLRAs lead to excellent results, with variational heteroscedastic (VH) Gaussian Processes regression (GPR) as the best performing method, with a RCV2 of 0.90 (RMSECV : 0.44). Additionally, the model is trained and validated relatively fast (1.70 s) and the processed image (taking 73.88 s) includes associated uncertainty estimates. More challenging is the inversion of a PROSAIL based radiative transfer model (RTM). After the generation of a look-up table (LUT), a multitude of cost functions and regularization options were evaluated. The best performing cost function is Pearson's χ -square. It led to a R2 of 0.74 (RMSE: 0.80) against the validation dataset. While its validation went fast

  8. Stabilization of Transfected Cells Expressing Low-Incidence Blood Group Antigens: Novel Methods Facilitating Their Use as Reagent-Cells

    PubMed Central

    González, Cecilia; Esteban, Rosa; Canals, Carme; Muñiz-Díaz, Eduardo; Nogués, Núria

    2016-01-01

    Background The identification of erythrocyte antibodies in the serum of patients rely on panels of human red blood cells (RBCs), which coexpress many antigens and are not easily available for low-incidence blood group phenotypes. These problems have been addressed by generating cell lines expressing unique blood group antigens, which may be used as an alternative to human RBCs. However, the use of cell lines implies several drawbacks, like the requirement of cell culture facilities and the high cost of cryopreservation. The application of cell stabilization methods could facilitate their use as reagent cells in clinical laboratories. Methods We generated stably-transfected cells expressing low-incidence blood group antigens (Dia and Lua). High-expresser clones were used to assess the effect of TransFix® treatment and lyophilization as cell preservation methods. Cells were kept at 4°C and cell morphology, membrane permeability and antigenic properties were evaluated at several time-points after treatment. Results TransFix® addition to cell suspensions allows cell stabilization and proper antigen detection for at least 120 days, despite an increase in membrane permeability and a reduction in antigen expression levels. Lyophilized cells showed minor morphological changes and antigen expression levels were rather conserved at days 1, 15 and 120, indicating a high stability of the freeze-dried product. These stabilized cells have been proved to react specifically with human sera containing alloantibodies. Conclusions Both stabilization methods allow long-term preservation of the transfected cells antigenic properties and may facilitate their distribution and use as reagent-cells expressing low-incidence antigens, overcoming the limited availability of such rare RBCs. PMID:27603310

  9. A Method to Estimate Crop Effects in Passive Microwave Soil Moisture Retrieval Above C-band

    NASA Astrophysics Data System (ADS)

    Zhang, Z.; Xu, Y.; Shi, J.

    2009-12-01

    moisture) directly to the observed Brightness Temperature. On the other hand, τ-ω model is simple in formula and are widely used in soil moisture retrieval at L- or C-band. To characterize ω and t of short vegetation above C-band, we setup a Brightness Temperature database with M-D model by a variety of parameters. Then results from M-D model were matched with those from τ-ω model at the same environmental conditions by least-square deviation, so as to retrieve ω and t of vegetation above C-band. To verify the derived effective single scattering albedo ω and transmissivity t, they were used, together with the Brightness Temperature data during SMEX02/PSR flight, in τ-ω model. The results of the equation were emissivity of soil, which were then used by a Qp model to retrieve soil moisture in the same area where PSR flight passed. The retrieved soil moisture matched the measurement very good, the rmse is 0.0458. This showed our method to retrieve ω and t are reliable.

  10. Wind Profile Retrieval Method for Incoherent Doppler LIDAR in Partly Cloudy Conditions

    NASA Astrophysics Data System (ADS)

    Feng, Changzhong; Liu, Bingyi; Liu, Zhishen

    2014-11-01

    After the launch of ESA’s spaceborne Doppler lidar ALADIN, Ocean University of China is going to perform the ground validation using a ground based Doppler wind lidar which utilizes an iodine absorption filter as frequency discriminator to derive Doppler frequency shift of atmospheric wind from combined molecular and aerosol backscatter. Under circumstance of non-uniform aerosol horizontal distribution, such as partly cloudy conditions, the accuracy of wind measurements is seriously influenced. Therefore, an improved VAD (Velocity-Azimuth Display) method for retrieving wind profiles is developed, which significantly increases the accuracy. With the atmospheric return signal obtained from the line-of-sight velocity PPI (Plan Position Indicator) measurements, the spatial distribution of aerosol optical parameters can be derived and considered as a reference for the quality control of line-of-sight velocity. Consequently, the wind profile in partly cloudy conditions can be retrieved by using the quality controlled line-of-sight velocity. As a result, the applicability of the ground based Doppler lidar is improved.

  11. Tropospheric ozone retrieval by using SCIAMACHY Limb-Nadir-Matching method

    NASA Astrophysics Data System (ADS)

    Jia, Jia; Ladstätter-Weissenmayer, Annette; Ebojie, Felix; Rozanov, Alexei; Burrows, John

    2014-05-01

    Tropospheric ozone is photochemically produced during pollution events and transported from the stratosphere towards the troposphere. It is the third most important green house gases and the main component of summer smog. Global covered satellite measurements are well suitable to investigate sources, sinks, and transport mechanisms of tropospheric ozone in a global view, and to study a characteristic behaviour of the tropospheric ozone in regions. However, the usage of satellite data is associated to a large uncertainty as 90% ozone is located in the stratosphere and only the remaining part of 10% can be observed in the troposphere. The limb-nadir matching (LNM) technique is one of the methods suitable to retrieve tropospheric ozone distributions from space borne observations of the scattered solar light in the UV-visible spectral range. In this study we apply the LNM approach to alternating limb and nadir measurements performed by the SCIAMACHY instrument. A precise tropopause height is used to subtract the stratospheric ozone from the total ozone amount for each matching point. The focus of this work is to reduce the uncertainty of the resulting tropospheric ozone distributions by analysing possible error sources, refining both limb and nadir retrievals and the matching technique.

  12. Practical Evaluation of Methods for Detection and Specificity of Autoantibodies to Extractable Nuclear Antigens

    PubMed Central

    Orton, Susan M.; Peace-Brewer, Amy; Schmitz, John L.; Freeman, Kristie; Miller, William C.; Folds, James D.

    2004-01-01

    Detection and specificity of autoantibodies against extractable nuclear antigens (ENA) play a critical role in the diagnosis and management of autoimmune disease. Historically, the detection of these antibodies has employed double immunodiffusion (DID). Autoantibody specificity was correlated with diagnoses by this technique. Enzyme immunoassays have been developed by multiple manufacturers to detect and identify the specificity ENA autoantibodies. To address the relationship of ENA detection by DID and enzyme immunoassay, the performances of five immunoassays were compared. These included two DID and three enzyme-linked immunoassays (ELISA) (both screening and individual antigen profile kits). The sample set included 83 ENA-positive, antinuclear-antibody (ANA)-positive specimens, 77 ENA-negative, ANA-positive specimens, and 20 ENA- and ANA-negative specimens. Sensitivity and specificity were calculated by two methods: first, by using the in-house DID result as the reference standard, and second, by using latent class analysis, which evaluates each kit result independently. Overall, the results showed that the ELISA methods were more sensitive for detection of ENA autoantibodies than DID techniques, but presence and/or specific type of ENA autoantibody did not always correlate with the patient's clinical presentation. Regardless of the testing strategy an individual laboratory uses, clear communication with the clinical staff regarding the significance of a positive result is imperative. The laboratory and the clinician must both be aware of the sensitivity and specificity of each testing method in use in the clinical laboratory. PMID:15013979

  13. A modified PCR-SSP method for the identification of ABO blood group antigens.

    PubMed

    Downing, J; Darke, C

    2003-08-01

    The ABO blood group antigens are carbohydrate molecules synthesized by the glycosyltransferases encoded by the ABO gene on chromosome 9. Kidney transplantation across the ABO barrier generally leads to rapid humoral graft rejection due to the presence of naturally occurring antibodies to the A and B antigens. We have developed a method for ABO typing our cadaveric organ donors by the polymerase chain reaction using sequence-specific primers (PCR-SSP). The method uses 12 primers in eight PCR mixtures and is performed under the same conditions as our routine HLA-A, B, C PCR-SSP typing. The PCR-SSP-based types of 166 regular blood donors and 148 cadaveric organ donors all showed total concordance with their serologically assigned ABO groups. Six individuals possessing the ABO A subgroups (A3, Ax and Aend) all typed as A1 by PCR-SSP, as expected. PCR-SSP is an appropriate method for ABO typing of cadaveric organ donors and, importantly, enables both ABO and HLA typing to be performed on the same DNA material.

  14. Improved poliovirus D-antigen yields by application of different Vero cell cultivation methods.

    PubMed

    Thomassen, Yvonne E; Rubingh, Olaf; Wijffels, René H; van der Pol, Leo A; Bakker, Wilfried A M

    2014-05-19

    Vero cells were grown adherent to microcarriers (Cytodex 1; 3 g L(-1)) using animal component free media in stirred-tank type bioreactors. Different strategies for media refreshment, daily media replacement (semi-batch), continuous media replacement (perfusion) and recirculation of media, were compared with batch cultivation. Cell densities increased using a feed strategy from 1×10(6) cells mL(-1) during batch cultivation to 1.8, 2.7 and 5.0×10(6) cells mL(-1) during semi-batch, perfusion and recirculation, respectively. The effects of these different cell culture strategies on subsequent poliovirus production were investigated. Increased cell densities allowed up to 3 times higher D-antigen levels when compared with that obtained from batch-wise Vero cell culture. However, the cell specific D-antigen production was lower when cells were infected at higher cell densities. This cell density effect is in good agreement with observations for different cell lines and virus types. From the evaluated alternative culture methods, application of a semi-batch mode of operations allowed the highest cell specific D-antigen production. The increased product yields that can easily be reached using these higher cell density cultivation methods, showed the possibility for better use of bioreactor capacity for the manufacturing of polio vaccines to ultimately reduce vaccine cost per dose. Further, the use of animal-component-free cell- and virus culture media shows opportunities for modernization of human viral vaccine manufacturing. PMID:24583004

  15. Retrieval of water vapor mixing ratio from a multiple channel Raman-scatter lidar using an optimal estimation method.

    PubMed

    Sica, R J; Haefele, A

    2016-02-01

    Lidar measurements of the atmospheric water vapor mixing ratio provide an excellent complement to radiosoundings and passive, ground-based remote sensors. Lidars are now routinely used that can make high spatial-temporal resolution measurements of water vapor from the surface to the stratosphere. Many of these systems can operate during the day and night, with operation only limited by clouds thick enough to significantly attenuate the laser beam. To enhance the value of these measurements for weather and climate studies, this paper presents an optimal estimation method (OEM) to retrieve the water vapor mixing ratio, aerosol optical depth profile, Ångstrom exponent, lidar constants, detector dead times, and measurement backgrounds from multichannel vibrational Raman-scatter lidars. The OEM retrieval provides the systematic uncertainties due to the overlap function, calibration factor, air density and Rayleigh-scatter cross sections, in addition to the random uncertainties of the retrieval due to measurement noise. The OEM also gives the vertical resolution of the retrieval as a function of height, as well as the height to which the contribution of the a priori is small. The OEM is applied to measurements made by the Meteoswiss Raman Lidar for Meteorological Observations (RALMO) in the day and night for clear and cloudy conditions. The retrieved water vapor mixing ratio is in excellent agreement with both the traditional lidar retrieval method and coincident radiosoundings. PMID:26836078

  16. Retrieval of water vapor mixing ratio from a multiple channel Raman-scatter lidar using an optimal estimation method.

    PubMed

    Sica, R J; Haefele, A

    2016-02-01

    Lidar measurements of the atmospheric water vapor mixing ratio provide an excellent complement to radiosoundings and passive, ground-based remote sensors. Lidars are now routinely used that can make high spatial-temporal resolution measurements of water vapor from the surface to the stratosphere. Many of these systems can operate during the day and night, with operation only limited by clouds thick enough to significantly attenuate the laser beam. To enhance the value of these measurements for weather and climate studies, this paper presents an optimal estimation method (OEM) to retrieve the water vapor mixing ratio, aerosol optical depth profile, Ångstrom exponent, lidar constants, detector dead times, and measurement backgrounds from multichannel vibrational Raman-scatter lidars. The OEM retrieval provides the systematic uncertainties due to the overlap function, calibration factor, air density and Rayleigh-scatter cross sections, in addition to the random uncertainties of the retrieval due to measurement noise. The OEM also gives the vertical resolution of the retrieval as a function of height, as well as the height to which the contribution of the a priori is small. The OEM is applied to measurements made by the Meteoswiss Raman Lidar for Meteorological Observations (RALMO) in the day and night for clear and cloudy conditions. The retrieved water vapor mixing ratio is in excellent agreement with both the traditional lidar retrieval method and coincident radiosoundings.

  17. Validation of GOSAT SWIR XCO2 and XCH4 retrieved by PPDF-S method

    NASA Astrophysics Data System (ADS)

    Iwasaki, C.; Hayashida, S.; Imasu, R.; Ono, A.; Yokota, T.; Morino, I.; Yoshida, Y.; Oshchepkov, S.; Bril, A.

    2015-12-01

    Photon path length probability density function (PPDF)-based method is an effective algorithm for retrieving columnar concentrations of carbon dioxide and methane (XCO2 and XCH4) from Greenhouse gases Observing SATellite (GOSAT) data, even under conditions of high aerosol concentrations. Few studies have validated XCO2 analyzed using a PPDF-based method, and no report describes validation for XCH4. In this study, we validated both XCO2 and XCH4 data analyzed using an advanced version of PPDF, PPDF-simultaneous (PPDF-S), by comparing the retrieved data with the Total Carbon Column Observing Network (TCCON) data (GGG 2012 and 2014 releases) observed at 11 observation sites. As the first step, our validation procedure was applied to the NIES standard products of XCO2 and XCH4 (V02.xx) to confirm its performance. Results show that the biases ±their standard devations, defined by the difference from TCCON data (GGG 2012), were evaluated to be -1.94±1.79 ppm and -7.59±11.8 ppb, respectively, for XCO2 and XCH4, using radiance data used for NIES V02.11, and to be -1.63±1.88 ppm and -6.45±12.2 ppb using data for NIES V02.21. Absolute values of these biases are slightly larger than those from Yoshida et al. (2013) reported as -1.56±1.88 ppm and -6.10±12.3 ppb for XCO2 and XCH4, respectively using radiance data used for NIES V02.00. The validation procedure was then applied to XCO2 and XCH4 analyzed using PPDF-S. Results show that biases are 0.16±1.77 ppm and 4.18±14.3 ppb, respectively, for XCO2 and XCH4 using radiance used for NIES V02.11. They are 0.27±1.72 ppm and 4.54±14.4 ppb using data for NIES V02.21. We conclude that PPDF-S method exhibits better performance for both XCO2 and XCH4 retrieval than for NIES standard products where TCCON (GGG 2012) data are used as validation data, although the standard products might be better for XCH4 if TCCON (GGG 2014) data are used.

  18. Land surface temperature retrieval from Landsat 8 TIRS: comparison between split window algorithm and SEBAL method

    NASA Astrophysics Data System (ADS)

    Valizadeh Kamran, Khalil; Pirnazar, Mojtaba; Farhadi Bansouleh, Vida

    2015-06-01

    Land surface temperature (LST) is a key parameter in the physics of the earth surface through the process of energy and water exchange with the atmosphere, which plays an important role in a wide variety of scientific studies, such as ecology, hydrology, and global change studies. Thermal infrared (TIR) remote sensing provides a unique method for obtaining LST information at the regional and global scales since most of the energy detected by the sensor in this spectral region is directly emitted by the land surface. Landsat 8 Thermal Infrared Sensor (TIRS), because of two adjacent thermal bands, band 10 between 10.30-11.30 μm and band 11 between 11.30-12.30 μm, and availability of its images is a good source for retrieving LST. In this study, we compared two different methods for LST inversions from TIRS including the Split Window method and the SEBAL method for Tehran , Iran.. Results show that the LST inverted from the Split Window method has the accuracy with RMSE lower than 1.17 ˚ C, while the SEBAL method has the accuracy with 3.27 ˚ C, so the Split Window algorithm is appropriate method for this study area.

  19. A Method to Retrieve Rainfall Rate Over Land from TRMM Microwave Imager Observations

    NASA Technical Reports Server (NTRS)

    Prabhakara, C.; Iacovazzi, R., Jr.; Yoo, J.-M.; Lau, William K. M. (Technical Monitor)

    2002-01-01

    Over tropical land regions, rain rate maxima in mesoscale convective systems revealed by the Precipitation Radar (PR) flown on the Tropical Rainfall Measuring Mission (TRMM) satellite are found to correspond to thunderstorms, i.e., Cbs. These Cbs are reflected as minima in the 85 GHz brightness temperature, T85, observed by the TRMM Microwave Imager (TMI) radiometer. Because the magnitude of TMI observations do not discriminate satisfactorily convective and stratiform rain, we developed here a different TMI discrimination method. In this method, two types of Cbs, strong and weak, are inferred from the Laplacian of T85 at minima. Then, to retrieve rain rate, where T85 is less than 270 K, a weak (background) rain rate is deduced using T85 observations. Furthermore, over a circular area of 10 km radius centered at the location of each T85 minimum, an additional Cb component of rain rate is added to the background rain rate. This Cb component of rain rate is estimated with the help of (T19-T37) and T85 observations. Initially, our algorithm is calibrated with the PR rain rate measurements from 20 MCS rain events. After calibration, this method is applied to TMI data taken from several tropical land regions. With the help of the PR observations, we show that the spatial distribution and intensity of rain rate over land estimated from our algorithm are better than those given by the current TMI-Version-5 Algorithm. For this reason, our algorithm may be used to improve the current state of rain retrievals on land.

  20. A safe and efficient method to retrieve mesenchymal stem cells from three-dimensional fibrin gels.

    PubMed

    Carrion, Bita; Janson, Isaac A; Kong, Yen P; Putnam, Andrew J

    2014-03-01

    Mesenchymal stem cells (MSCs) display multipotent characteristics that make them ideal for potential therapeutic applications. MSCs are typically cultured as monolayers on tissue culture plastic, but there is increasing evidence suggesting that they may lose their multipotency over time in vitro and eventually cease to retain any resemblance to in vivo resident MSCs. Three-dimensional (3D) culture systems that more closely recapitulate the physiological environment of MSCs and other cell types are increasingly explored for their capacity to support and maintain the cell phenotypes. In much of our own work, we have utilized fibrin, a natural protein-based material that serves as the provisional extracellular matrix during wound healing. Fibrin has proven to be useful in numerous tissue engineering applications and has been used clinically as a hemostatic material. Its rapid self-assembly driven by thrombin-mediated alteration of fibrinogen makes fibrin an attractive 3D substrate, in which cells can adhere, spread, proliferate, and undergo complex morphogenetic programs. However, there is a significant need for simple cost-effective methods to safely retrieve cells encapsulated within fibrin hydrogels to perform additional analyses or use the cells for therapy. Here, we present a safe and efficient protocol for the isolation of MSCs from 3D fibrin gels. The key ingredient of our successful extraction method is nattokinase, a serine protease of the subtilisin family that has a strong fibrinolytic activity. Our data show that MSCs recovered from 3D fibrin gels using nattokinase are not only viable but also retain their proliferative and multilineage potentials. Demonstrated for MSCs, this method can be readily adapted to retrieve any other cell type from 3D fibrin gel constructs for various applications, including expansion, bioassays, and in vivo implantation.

  1. A Safe and Efficient Method to Retrieve Mesenchymal Stem Cells from Three-Dimensional Fibrin Gels

    PubMed Central

    Carrion, Bita; Janson, Isaac A.; Kong, Yen P.

    2014-01-01

    Mesenchymal stem cells (MSCs) display multipotent characteristics that make them ideal for potential therapeutic applications. MSCs are typically cultured as monolayers on tissue culture plastic, but there is increasing evidence suggesting that they may lose their multipotency over time in vitro and eventually cease to retain any resemblance to in vivo resident MSCs. Three-dimensional (3D) culture systems that more closely recapitulate the physiological environment of MSCs and other cell types are increasingly explored for their capacity to support and maintain the cell phenotypes. In much of our own work, we have utilized fibrin, a natural protein-based material that serves as the provisional extracellular matrix during wound healing. Fibrin has proven to be useful in numerous tissue engineering applications and has been used clinically as a hemostatic material. Its rapid self-assembly driven by thrombin-mediated alteration of fibrinogen makes fibrin an attractive 3D substrate, in which cells can adhere, spread, proliferate, and undergo complex morphogenetic programs. However, there is a significant need for simple cost-effective methods to safely retrieve cells encapsulated within fibrin hydrogels to perform additional analyses or use the cells for therapy. Here, we present a safe and efficient protocol for the isolation of MSCs from 3D fibrin gels. The key ingredient of our successful extraction method is nattokinase, a serine protease of the subtilisin family that has a strong fibrinolytic activity. Our data show that MSCs recovered from 3D fibrin gels using nattokinase are not only viable but also retain their proliferative and multilineage potentials. Demonstrated for MSCs, this method can be readily adapted to retrieve any other cell type from 3D fibrin gel constructs for various applications, including expansion, bioassays, and in vivo implantation. PMID:23808842

  2. A Multi-Channel Method for Retrieving Surface Temperature for High-Emissivity Surfaces from Hyperspectral Thermal Infrared Images.

    PubMed

    Zhong, Xinke; Labed, Jelila; Zhou, Guoqing; Shao, Kun; Li, Zhao-Liang

    2015-06-08

    The surface temperature (ST) of high-emissivity surfaces is an important parameter in climate systems. The empirical methods for retrieving ST for high-emissivity surfaces from hyperspectral thermal infrared (HypTIR) images require spectrally continuous channel data. This paper aims to develop a multi-channel method for retrieving ST for high-emissivity surfaces from space-borne HypTIR data. With an assumption of land surface emissivity (LSE) of 1, ST is proposed as a function of 10 brightness temperatures measured at the top of atmosphere by a radiometer having a spectral interval of 800-1200 cm(-1) and a spectral sampling frequency of 0.25 cm(-1). We have analyzed the sensitivity of the proposed method to spectral sampling frequency and instrumental noise, and evaluated the proposed method using satellite data. The results indicated that the parameters in the developed function are dependent on the spectral sampling frequency and that ST of high-emissivity surfaces can be accurately retrieved by the proposed method if appropriate values are used for each spectral sampling frequency. The results also showed that the accuracy of the retrieved ST is of the order of magnitude of the instrumental noise and that the root mean square error (RMSE) of the ST retrieved from satellite data is 0.43 K in comparison with the AVHRR SST product.

  3. A Multi-Channel Method for Retrieving Surface Temperature for High-Emissivity Surfaces from Hyperspectral Thermal Infrared Images

    PubMed Central

    Zhong, Xinke; Labed, Jelila; Zhou, Guoqing; Shao, Kun; Li, Zhao-Liang

    2015-01-01

    The surface temperature (ST) of high-emissivity surfaces is an important parameter in climate systems. The empirical methods for retrieving ST for high-emissivity surfaces from hyperspectral thermal infrared (HypTIR) images require spectrally continuous channel data. This paper aims to develop a multi-channel method for retrieving ST for high-emissivity surfaces from space-borne HypTIR data. With an assumption of land surface emissivity (LSE) of 1, ST is proposed as a function of 10 brightness temperatures measured at the top of atmosphere by a radiometer having a spectral interval of 800–1200 cm−1 and a spectral sampling frequency of 0.25 cm−1. We have analyzed the sensitivity of the proposed method to spectral sampling frequency and instrumental noise, and evaluated the proposed method using satellite data. The results indicated that the parameters in the developed function are dependent on the spectral sampling frequency and that ST of high-emissivity surfaces can be accurately retrieved by the proposed method if appropriate values are used for each spectral sampling frequency. The results also showed that the accuracy of the retrieved ST is of the order of magnitude of the instrumental noise and that the root mean square error (RMSE) of the ST retrieved from satellite data is 0.43 K in comparison with the AVHRR SST product. PMID:26061199

  4. Demonstration of retrieval methods for Westinghouse Hanford Corporation October 20, 1995

    SciTech Connect

    1996-10-01

    Westinghouse Hanford Corporation has been pursuing strategies to break up and retrieve the radioactive waste material in single shell storage tanks at the Hanford Nuclear Reservation, by working with non-radioactive ``saltcake`` and sludge material that simulate the actual waste. It has been suggested that the use of higher volumes of water than used in the past (10 gpm nozzles at 10,000 psi) might be successful in breaking down the hard waste simulants. Additionally, the application of these higher volumes of water might successfully be applied through commercially available tooling using methods similar to those used in the deslagging of large utility boilers. NMW Industrial Services, Inc., has proposed a trial consisting of three approaches each to dislodging both the solid (saltcake) simulant and the sludge simulant.

  5. Method for indexing and retrieving manufacturing-specific digital imagery based on image content

    DOEpatents

    Ferrell, Regina K.; Karnowski, Thomas P.; Tobin, Jr., Kenneth W.

    2004-06-15

    A method for indexing and retrieving manufacturing-specific digital images based on image content comprises three steps. First, at least one feature vector can be extracted from a manufacturing-specific digital image stored in an image database. In particular, each extracted feature vector corresponds to a particular characteristic of the manufacturing-specific digital image, for instance, a digital image modality and overall characteristic, a substrate/background characteristic, and an anomaly/defect characteristic. Notably, the extracting step includes generating a defect mask using a detection process. Second, using an unsupervised clustering method, each extracted feature vector can be indexed in a hierarchical search tree. Third, a manufacturing-specific digital image associated with a feature vector stored in the hierarchicial search tree can be retrieved, wherein the manufacturing-specific digital image has image content comparably related to the image content of the query image. More particularly, can include two data reductions, the first performed based upon a query vector extracted from a query image. Subsequently, a user can select relevant images resulting from the first data reduction. From the selection, a prototype vector can be calculated, from which a second-level data reduction can be performed. The second-level data reduction can result in a subset of feature vectors comparable to the prototype vector, and further comparable to the query vector. An additional fourth step can include managing the hierarchical search tree by substituting a vector average for several redundant feature vectors encapsulated by nodes in the hierarchical search tree.

  6. Retrieval practice is an efficient method of enhancing the retention of anatomy and physiology information.

    PubMed

    Dobson, John L

    2013-06-01

    Although a great deal of empirical evidence has indicated that retrieval practice is an effective means of promoting learning and memory, very few studies have investigated the strategy in the context of an actual class. The primary purpose of this study was to determine if a series of very brief retrieval quizzes could significantly improve the retention of previously tested information throughout an anatomy and physiology course. A second purpose was to determine if there were any significant differences between expanding and uniform patterns of retrieval that followed a standardized initial retrieval delay. Anatomy and physiology students were assigned to either a control group or groups that were repeatedly prompted to retrieve a subset of previously tested course information via a series of quizzes that were administered on either an expanding or a uniform schedule. Each retrieval group completed a total of 10 retrieval quizzes, and the series of quizzes required (only) a total of 2 h to complete. Final retention of the exam subset material was assessed during the last week of the semester. There were no significant differences between the expanding and uniform retrieval groups, but both retained an average of 41% more of the subset material than did the control group (ANOVA, F = 129.8, P = 0.00, ηp(2) = 0.36). In conclusion, retrieval practice is a highly efficient and effective strategy for enhancing the retention of anatomy and physiology material.

  7. Validation of GOES-Derived Surface Radiation Using NOAA's Physical Retrieval Method

    SciTech Connect

    Habte, A.; Sengupta, M.; Wilcox, S.

    2013-01-01

    This report was part of a multiyear collaboration with the University of Wisconsin and the National Oceanic and Atmospheric Administration (NOAA) to produce high-quality, satellite-based, solar resource datasets for the United States. High-quality, solar resource assessment accelerates technology deployment by making a positive impact on decision making and reducing uncertainty in investment decisions. Satellite-based solar resource datasets are used as a primary source in solar resource assessment. This is mainly because satellites provide larger areal coverage and longer periods of record than ground-based measurements. With the advent of newer satellites with increased information content and faster computers that can process increasingly higher data volumes, methods that were considered too computationally intensive are now feasible. One class of sophisticated methods for retrieving solar resource information from satellites is a two-step, physics-based method that computes cloud properties and uses the information in a radiative transfer model to compute solar radiation. This method has the advantage of adding additional information as satellites with newer channels come on board. This report evaluates the two-step method developed at NOAA and adapted for solar resource assessment for renewable energy with the goal of identifying areas that can be improved in the future.

  8. Content based Image Retrieval based on Different Global and Local Color Histogram Methods: A Survey

    NASA Astrophysics Data System (ADS)

    Suhasini, Pallikonda Sarah; Sri Rama Krishna, K.; Murali Krishna, I. V.

    2016-06-01

    Different global and local color histogram methods for content based image retrieval (CBIR) are investigated in this paper. Color histogram is a widely used descriptor for CBIR. Conventional method of extracting color histogram is global, which misses the spatial content, is less invariant to deformation and viewpoint changes, and results in a very large three dimensional histogram corresponding to the color space used. To address the above deficiencies, different global and local histogram methods are proposed in recent research. Different ways of extracting local histograms to have spatial correspondence, invariant colour histogram to add deformation and viewpoint invariance and fuzzy linking method to reduce the size of the histogram are found in recent papers. The color space and the distance metric used are vital in obtaining color histogram. In this paper the performance of CBIR based on different global and local color histograms in three different color spaces, namely, RGB, HSV, L*a*b* and also with three distance measures Euclidean, Quadratic and Histogram intersection are surveyed, to choose appropriate method for future research.

  9. Retrieving Forest Structure Variables from Very High Resolution Satellite Images Using AN Automatic Method

    NASA Astrophysics Data System (ADS)

    Beguet, B.; Chehata, N.; Boukir, S.; Guyon, D.

    2012-07-01

    were tested using multiple linear regressions. As collinearity is a very perturbing problem in multi-linear regression, this issue is carefully addressed. Different variables subset selection methods are tested. A new stepwise method, derived from LARS (Least Angular Regression), turned out the most convincing, significantly improving the quality of estimation for all the forest structure variables (R2 > 0:98). Validation is done through stand ages retrieval along the whole site. The best estimation results are obtained from subsets combining multi-spectral and panchromatic features, with various values of window size, highlighting the potential of a multi-scale approach for retrieving forest structure variables from VHR satellite images.

  10. Latent Semantic Analysis as a Method of Content-Based Image Retrieval in Medical Applications

    ERIC Educational Resources Information Center

    Makovoz, Gennadiy

    2010-01-01

    The research investigated whether a Latent Semantic Analysis (LSA)-based approach to image retrieval can map pixel intensity into a smaller concept space with good accuracy and reasonable computational cost. From a large set of M computed tomography (CT) images, a retrieval query found all images for a particular patient based on semantic…

  11. Retrieval Practice Is an Efficient Method of Enhancing the Retention of Anatomy and Physiology Information

    ERIC Educational Resources Information Center

    Dobson, John L.

    2013-01-01

    Although a great deal of empirical evidence has indicated that retrieval practice is an effective means of promoting learning and memory, very few studies have investigated the strategy in the context of an actual class. The primary purpose of this study was to determine if a series of very brief retrieval quizzes could significantly improve the…

  12. Evaluation of the Secretor Status of ABO Blood Group Antigens in Saliva among Southern Rajasthan Population Using Absorption Inhibition Method

    PubMed Central

    Khajuria, Nidhi; Mamta; Ramesh, Gayathri

    2016-01-01

    Introduction The ABO blood group system was the significant element for forensic serological examination of blood and body fluids in the past before the wide adaptation of DNA typing. A significant proportion of individuals (80%) are secretors, meaning that antigens present in the blood are also found in other body fluids such as saliva. Absorption inhibition is one such method that works by reducing strength of an antiserum based on type and amount of antigen present in the stains. Aim To check the efficacy of identifying the blood group antigens in saliva and to know the secretor status using absorption inhibition method among southern Rajasthan population. Materials and Methods Blood and saliva samples were collected from 80 individuals comprising 20 individuals in each blood group. The absorption inhibition method was used to determine the blood group antigens in the saliva and then the results were correlated with the blood group of the collected blood sample. The compiled data was statistically analysed using chi-square test. Results Blood groups A & O revealed 100% secretor status for both males and females. While blood groups B and AB revealed 95% secretor status. Conclusion Secretor status evaluation of the ABO blood group antigen in saliva using absorption inhibition method can be a useful tool in forensic examination. PMID:27042574

  13. Characterization of freshly retrieved preantral follicles using a low-invasive, mechanical isolation method extended to different ruminant species.

    PubMed

    Langbeen, A; Jorssen, E P A; Fransen, E; Rodriguez, A P A; García, M Chong; Leroy, J L M R; Bols, P E J

    2015-10-01

    Due to the increased interest in preantral follicular physiology, non-invasive retrieval and morphological classification are crucial. Therefore, this study aimed: (1) to standardize a minimally invasive isolation protocol, applicable to three ruminant species; (2) to morphologically classify preantral follicles upon retrieval; and (3) to describe morphological features of freshly retrieved follicles compared with follicle characteristics using invasive methods. Bovine, caprine and ovine ovarian cortex strips were retrieved from slaughterhouse ovaries and dispersed. This suspension was filtered, centrifuged, re-suspended and transferred to a Petri dish, to which 0.025 mg/ml neutral red (NR) was added to assess the viability of the isolated follicles. Between 59 and 191 follicles per follicle class and per species were collected and classified by light microscopy, based on follicular cell morphology. Subsequently, follicle diameters were measured. The proposed isolation protocol was applicable to all three species and showed a significant, expected increase in diameter with developmental stage. With an average diameter of 37 ± 5 μm for primordial follicles, 47 ± 6.3 μm for primary follicles and 67.1 ± 13.1 μm for secondary follicles, no significant difference in diameter among the three species was observed. Bovine, caprine and ovine follicles (63, 59 and 50% respectively) were graded as viable upon retrieval. Using the same morphological characteristics as determined by invasive techniques [e.g. haematoxylin-eosin (HE) sections], cumulus cell morphology and follicle diameter could be used routinely to classify freshly retrieved follicles. Finally, we applied a mechanical, minimally invasive, follicle isolation protocol and extended it to three ruminant species, yielding viable preantral follicles without compromising further in vitro processing and allowing routine follicle characterization upon retrieval.

  14. Regional content-based image retrieval for solar images: Traditional versus modern methods

    NASA Astrophysics Data System (ADS)

    Banda, J. M.; Angryk, R. A.

    2015-11-01

    This work presents an extensive evaluation between conventional (distance-based) and modern (search-engine) information retrieval techniques in the context of finding similar Solar image regions within the Solar Dynamics Observatory (SDO) mission image repository. We compare pre-computed image descriptors (image features) extracted from the SDO mission images in two very different ways: (1) similarity retrieval using multiple distance-based metrics and (2) retrieval using Lucene, a general purpose scalable retrieval engine. By transforming image descriptors into histogram-like signatures and into Lucene-compatible text strings, we are able to effectively evaluate the retrieval capabilities of both methodologies. Using the image descriptors alongside a labeled image dataset, we present an extensive evaluation under the criteria of performance, scalability and retrieval precision of experimental retrieval systems in order to determine which implementation would be ideal for a production level system. In our analysis we performed key transformations to our sample datasets to properly evaluate rotation invariance and scalability. At the end of this work we conclude which technique is the most robust and would yield the best performing system after an extensive experimental evaluation, we also point out the strengths and weaknesses of each approach and theorize on potential improvements.

  15. Retrieving Leaf Area Index (LAI) Using Remote Sensing: Theories, Methods and Sensors

    PubMed Central

    Zheng, Guang; Moskal, L. Monika

    2009-01-01

    The ability to accurately and rapidly acquire leaf area index (LAI) is an indispensable component of process-based ecological research facilitating the understanding of gas-vegetation exchange phenomenon at an array of spatial scales from the leaf to the landscape. However, LAI is difficult to directly acquire for large spatial extents due to its time consuming and work intensive nature. Such efforts have been significantly improved by the emergence of optical and active remote sensing techniques. This paper reviews the definitions and theories of LAI measurement with respect to direct and indirect methods. Then, the methodologies for LAI retrieval with regard to the characteristics of a range of remotely sensed datasets are discussed. Remote sensing indirect methods are subdivided into two categories of passive and active remote sensing, which are further categorized as terrestrial, aerial and satellite-born platforms. Due to a wide variety in spatial resolution of remotely sensed data and the requirements of ecological modeling, the scaling issue of LAI is discussed and special consideration is given to extrapolation of measurement to landscape and regional levels. PMID:22574042

  16. A novel method for efficient archiving and retrieval of biomedical images using MPEG-7

    NASA Astrophysics Data System (ADS)

    Meyer, Joerg; Pahwa, Ash

    2004-10-01

    Digital archiving and efficient retrieval of radiological scans have become critical steps in contemporary medical diagnostics. Since more and more images and image sequences (single scans or video) from various modalities (CT/MRI/PET/digital X-ray) are now available in digital formats (e.g., DICOM-3), hospitals and radiology clinics need to implement efficient protocols capable of managing the enormous amounts of data generated daily in a typical clinical routine. We present a method that appears to be a viable way to eliminate the tedious step of manually annotating image and video material for database indexing. MPEG-7 is a new framework that standardizes the way images are characterized in terms of color, shape, and other abstract, content-related criteria. A set of standardized descriptors that are automatically generated from an image is used to compare an image to other images in a database, and to compute the distance between two images for a given application domain. Text-based database queries can be replaced with image-based queries using MPEG-7. Consequently, image queries can be conducted without any prior knowledge of the keys that were used as indices in the database. Since the decoding and matching steps are not part of the MPEG-7 standard, this method also enables searches that were not planned by the time the keys were generated.

  17. Epstein-Barr virus viral capsid antigen titer by immunofluorescence with microplates: new semiautomated method based on the microtiter system.

    PubMed

    Lamy, M E; Favart, A M; Burtonboy, G; Arana, A

    1977-07-01

    A semiautomated method of an indirect immunofluorescence technique for the titration of antibodies directed against viral capsid antigens of Epstein-Barr virus has been developed with Microtiter system units. By this method, a technician is able to titrate some hundred samples daily. The technique is safe, easy, and reproducible. The various procedures are described, and the sensitivity of the test is discussed.

  18. Comparative analysis of different retrieval methods for mapping grassland leaf area index using airborne imaging spectroscopy

    NASA Astrophysics Data System (ADS)

    Atzberger, Clement; Darvishzadeh, Roshanak; Immitzer, Markus; Schlerf, Martin; Skidmore, Andrew; le Maire, Guerric

    2015-12-01

    Fine scale maps of vegetation biophysical variables are useful status indicators for monitoring and managing national parks and endangered habitats. Here, we assess in a comparative way four different retrieval methods for estimating leaf area index (LAI) in grassland: two radiative transfer model (RTM) inversion methods (one based on look-up-tables (LUT) and one based on predictive equations) and two statistical modelling methods (one partly, the other entirely based on in situ data). For prediction, spectral data were used that had been acquired over Majella National Park in Italy by the airborne hyperspectral HyMap instrument. To assess the performance of the four investigated models, the normalized root mean squared error (nRMSE) and coefficient of determination (R2) between estimates and in situ LAI measurements are reported (n = 41). Using a jackknife approach, we also quantified the accuracy and robustness of empirical models as a function of the size of the available calibration data set. The results of the study demonstrate that the LUT-based RTM inversion yields higher accuracies for LAI estimation (R2 = 0.91, nRMSE = 0.18) as compared to RTM inversions based on predictive equations (R2 = 0.79, nRMSE = 0.38). The two statistical methods yield accuracies similar to the LUT method. However, as expected, the accuracy and robustness of the statistical models decrease when the size of the calibration database is reduced to fewer samples. The results of this study are of interest for the remote sensing community developing improved inversion schemes for spaceborne hyperspectral sensors applicable to different vegetation types. The examples provided in this paper may also serve as illustrations for the drawbacks and advantages of physical and empirical models.

  19. A three-dimensional polarization domain retrieval method from electron diffraction data.

    PubMed

    Pennington, Robert S; Koch, Christoph T

    2015-08-01

    We present an algorithm for retrieving three-dimensional domains of picometer-scale shifts in atomic positions from electron diffraction data, and apply it to simulations of ferroelectric polarization in BaTiO3. Our algorithm successfully and correctly retrieves polarization domains in which the Ti atom positions differ by less than 3 pm (0.4% of the unit cell diagonal distance) with 5 and 10nm depth resolution along the beam direction, and we also retrieve unit cell strain, corresponding to tetragonal-to-cubic unit cell distortions, for 10nm domains. Experimental applicability is also discussed.

  20. Method of retrieving a liquid sample, a suction lysimeter, a portable suction lysimeter, a lysimeter system, and a deep lysimeter

    DOEpatents

    Hubbell, Joel M.; Sisson, James B.

    2003-08-26

    A method of retrieving a liquid sample comprises providing a portable lysimeter including a semi-permeable membrane and a chamber in fluid communication with the semi-permeable membrane; making a hole at a site from which a liquid sample is desired; evacuating the chamber by applying a vacuum to the chamber; lowering the portable lysimeter into the hole; obtaining a sample in the chamber; and retrieving the lysimeter from the bore; wherein it is not necessary to backfill the bore. A portable lysimeter includes a semi-permeable member and a chamber in fluid communication with the semi-permeable membrane.

  1. Retrieval of Minor Species Densities From Limb Scatter Measurements by OSIRIS on Odin Using a Modified Onion Peeling Method

    NASA Astrophysics Data System (ADS)

    Auvinen, H.; Oikarinen, L.; Kyrola, E.; Siiskonen, T.; Hassinen, S.; Odin Team

    2002-05-01

    In this paper we present a Modified Onion Peeling (MOP) method to retrieve minor species densities from UV-visible limb scatter measurements by OSIRIS on Odin. We retrieve vertical profiles of ozone, NO2, OClO and BrO densities, and also aerosol and Rayleigh extinction from a limb scan between altitudes 60 (alternatively 120 km) to 7 km. The MOP method uses the whole UV-visible spectral range of OSIRIS. The large number of wavelength points minimizes the sensitivity of the retrieval to measurement noise. In order to relax requirements on absolute calibration the measurements are divided with a reference measurement made at a high tangent altitude by the same instrument. Multiple scattering is taken into account by pre-calculated total to single scattering radiance ratios tabulated as a function of wavelength, tangent altitude and several other relevant parameters. Our method uses air density profiles from ECMWF as a prior data for the simulation of the reference spectrum. A corresponding temperature profile from ECMWF is used also as a prior during the inversion process. The method uses absolute cross sections. We approximate the atmosphere to be locally spherically symmetric. The inversion is handled as a non-linear problem and several constituents are inverted simultaneously. We show first retrieval results from selected OSIRIS scans. These results are compared against validating measurements. Odin is a Swedish-led satellite project funded jointly by Sweden (SNSB), Canada (CSA), Finland (Tekes) and France (CNES).

  2. Novel Snow Depth Retrieval Method Using Time Series Ssmi Passive Microwave Imagery

    NASA Astrophysics Data System (ADS)

    Nikraftar, Z.; Hasanlou, M.; Esmaeilzadeh, M.

    2016-06-01

    The Special Sensor Microwave Imager (SSM/I) and the Special Sensor Microwave Imager Sounder (SSM/IS) are satellites that work in passive microwave range. The SSM/I has capability to measure geophysical parameters which these parameters are key to investigate the climate and hydrology condition in the world. In this research the SSMI passive microwave data is used to study the feasibility of monitoring snow depth during snowfall month from 2010 to 2015 using an algorithm in conjunction with ground depth measured at meteorological stations of the National Centre for Environmental Information (NCEI). The previous procedures for snow depth retrieval algorithms uses only one or two passive bands for modelling snow depth. This study enable us to use of a nonlinear multidimensional regression algorithm which incorporates all channels and their related weighting coefficients for each band. Higher value of these coefficients are indicator of the importance of each band in the regression model. All channels and their combination were used in support of the vector algorithm combined with genetic algorithm (GA) for feature selection to estimate snow depth. The results were compared with those algorithms developed by recent researchers and the results clearly shows the superiority of proposed method (R2 = 0.82 and RMSE = 6.3 cm).

  3. Connectionist Interaction Information Retrieval.

    ERIC Educational Resources Information Center

    Dominich, Sandor

    2003-01-01

    Discussion of connectionist views for adaptive clustering in information retrieval focuses on a connectionist clustering technique and activation spreading-based information retrieval model using the interaction information retrieval method. Presents theoretical as well as simulation results as regards computational complexity and includes…

  4. A Novel Method to Assess Wear Rates of Retrieved Tibial Inserts Following in-vivo Use

    NASA Astrophysics Data System (ADS)

    Paniogue, Tanille J.

    Ultra-high molecular weight polyethylene (UHMWPE) on cobalt chrome is the bearing couple of choice for total knee arthroplasty. The number of patients undergoing total knee arthroplasty has been steadily growing and is projected to continue increasing rapidly in the near future. Many of these patients are younger and more active and therefore need a longer lasting device. However, many of these devices fail prematurely and often the primary reason for failure and ultimately revision is due to wear related issues. Therefore, examining how wear rates of the UHMWPE tibial insert change during in-vivo use can help elucidate the mechanisms of accelerated wear and hopefully aid in finding solutions to combat wear related failures. Different crosslinking treatments have been employed by manufacturers to improve wear resistance of the polyethylene. While this has been shown to be an effective way to reduce wear, crosslinking has led to other issues such as oxidative instability and a decline in mechanical properties. The purpose of this body of work is to examine how changes in oxidation, after in-vivo use, affect wear resistance. A novel testing method was developed to test the native articular surface from retrieved tibial inserts in a laboratory Pin-on-Disk (POD) simulator. The method was validated using short-duration implant articular surfaces and non-articular control pins. In the absence of high surface oxidation or severe surface damage, the articular surface pins had comparable steady state wear rates to their bulk counterparts. Tests of devices with longer in-vivo service show chemical changes consistent with a free-radical mediated oxidation mechanism. Tribological assessment of the articular surfaces shows increasing wear rates as a function of oxidation. While this relationship has been hypothesized in the literature, these experiments represent the first physical demonstration of the phenomenon. The wear mechanism is further explored through infrared

  5. A review of the methods of studies on infant ultrasound production and maternal retrieval in small rodents.

    PubMed

    Hahn, Martin E; Lavooy, Maria J

    2005-01-01

    Ultrasonic vocalizations or calls produced by young rodents have been associated with aspects of maternal behavior, in particular retrieving. We reviewed the methods of study used by investigators on each topic, focusing on intrinsic or subject variables and extrinsic or experimental variables. Intrinsic variables included the species studied, genotypes employed, number and sex composition of the litters, and the ages of mothers and pups. Extrinsic variables for studies on ultrasonic calling included: eliciting stimuli, test surroundings, and the length of observation. Extrinsic variables in studies of maternal retrieval included the testing procedure and the length of observation. The methods used in studies within each topic vary greatly. In an effort to facilitate progress in the areas, especially with respect to isolating individual genes with a contribution to ultrasonic call production or studying the effects of pharmaceutical agents on either behavior, we propose some standardization of nomenclature and/or procedure in four areas: (1) the stimuli or situations used to elicit ultrasonic calls, (2) the length of observation in ultrasonic call studies, (3) the number of pups per litter and the sex composition of litters in both ultrasonic call and maternal retrieval studies and finally, (4) the apparatus or testing situation used in studies of pup retrieval.

  6. A computational method for identification of vaccine targets from protein regions of conserved human leukocyte antigen binding

    PubMed Central

    2015-01-01

    Background Computational methods for T cell-based vaccine target discovery focus on selection of highly conserved peptides identified across pathogen variants, followed by prediction of their binding of human leukocyte antigen molecules. However, experimental studies have shown that T cells often target diverse regions in highly variable viral pathogens and this diversity may need to be addressed through redefinition of suitable peptide targets. Methods We have developed a method for antigen assessment and target selection for polyvalent vaccines, with which we identified immune epitopes from variable regions, where all variants bind HLA. These regions, although variable, can thus be considered stable in terms of HLA binding and represent valuable vaccine targets. Results We applied this method to predict CD8+ T-cell targets in influenza A H7N9 hemagglutinin and significantly increased the number of potential vaccine targets compared to the number of targets discovered using the traditional approach where low-frequency peptides are excluded. Conclusions We developed a webserver with an intuitive visualization scheme for summarizing the T cell-based antigenic potential of any given protein or proteome using human leukocyte antigen binding predictions and made a web-accessible software implementation freely available at http://met-hilab.cbs.dtu.dk/blockcons/. PMID:26679766

  7. A simple and safe method for single HLA-antigen-typing by a solid phase assay.

    PubMed

    Häcker-Shahin, B; Giannitsis, D J

    1991-01-01

    A rapid solid phase assay for detection of single HLA-antigens on platelets was developed. The platelets were attached to the surface of polystyrene microtitre plate wells by means of a sodium carbonate buffer and centrifugation. Uncovered areas were blocked by a gelatin blocking buffer. After incubation with commercially available anti-HLA-sera the bound anti-HLA-specific antibodies directed against HLA-antigens present on the platelets were made visible by anti-IgG-coated indicator red cells and a brief centrifugation. A positive result, meaning the presence of an HLA-antigen, was indicated by a slight red cell adherence over the reaction surface. In the absence of the HLA-antigen no binding occurred and the indicator red cells formed a small red disc-like pellet.

  8. Methods for simultaneous interphase in situ hybridization and nuclear antigen immunocytochemistry in T47-D cells.

    PubMed

    Mialhe, A; Cassanelli, S; Louis, J; Seigneurin, D

    1996-02-01

    Procedures that combine immunocytochemistry (ICC) and in situ hybridization (ISH) techniques are now used to investigate phenotype/genotype relationships in the same cells. In this report we describe three rapid procedures for simultaneous detection of a nuclear antigen, progesterone receptors (PR), and the centromeric region of chromosome 11 (to which the human PR gene has been assigned) in T47-D cells. Proteins were stained by precipitates of horseradish peroxidase-diaminobenzidine (PO-DAB, brown color), alkaline phosphatase-Fast Red (APase-Fast Red, red color) or alkaline phosphatase-nitroblue tetrazolium-X-phosphate (APase-NBT-X-Phosphate, blue color) respectively. To obtain a suitable contrast for the two labels, we detected DNA on PO-DAB and APase-NBT-X-phosphate-immunostained cells with interphasic fluorescent in situ hybridization (FISH). By contrast, we combined the APase-Fast Red ICC with an immunocytochemical ISH using alkaline phosphatase-NBT-X-phosphate detection. Only the procedure combining APase-NBT-X-phosphate ICC and FISH ensures optimal visualization of both the PR content and the number of chromosome 11. This method easily provides simultaneous localization of DNA and protein targets in the same cells and should be applicable to many other situations. PMID:8609377

  9. The Hybrid Application of an Inductive Learning Method and a Neural Network for Intelligent Information Retrieval.

    ERIC Educational Resources Information Center

    Cortez, Edwin M.; And Others

    1995-01-01

    Proposes an information retrieval system based on a hybrid model consisting of an inductive learning and neural network system. Evaluates the system's responses to incomplete queries and inconsistent indexing. Query terms, discriminant descriptors, and the American Documentation Institute's query and document titles used in the evaluation are…

  10. Query Methods in Information Retrieval--Criteria for Selection and Application.

    ERIC Educational Resources Information Center

    Goldenson, A.F.; Cardwell, D.W.

    This report studies and classifies, according to distinct user-oriented features, the various computer-aided systems developed for storage and retrieval of information in a wide range of fields. Such features are described and evaluated to determine the nature of characteristics that have a strong bearing on the relative success of various query…

  11. Anti-noise algorithm of lidar data retrieval by combining the ensemble Kalman filter and the Fernald method.

    PubMed

    Mao, Feiyue; Gong, Wei; Li, Chen

    2013-04-01

    The lidar signal-to-noise ratio decreases rapidly with an increase in range, which severely affects the retrieval accuracy and the effective measure range of a lidar based on the Fernald method. To avoid this issue, an alternative approach is proposed to simultaneously retrieve lidar data accurately and obtain a de-noised signal as a by-product by combining the ensemble Kalman filter and the Fernald method. The dynamical model of the new algorithm is generated according to the lidar equation to forecast backscatter coefficients. In this paper, we use the ensemble sizes as 60 and the factor δ(1/2) as 1.2 after being weighed against the accuracy and the time cost based on the performance function we define. The retrieval and de-noising results of both simulated and real signals demonstrate that our method is practical and effective. An extensive application of our method can be useful for the long-term determining of the aerosol optical properties.

  12. Antigenic variation among bovine viral diarrhea virus (BVDV) strains and the role of different cell fixation methods in immunoassays.

    PubMed Central

    Elahi, S M; Harpin, S; Cornaglia, E; Talbot, B; Elazhary, Y

    1997-01-01

    Antigenic variation among 13 Quebec isolates of bovine viral diarrhea virus (BVDV), 4 reference strains and 2 American isolates were studied by peroxidase-linked antibody assay (PLA assay) and neutralization test (NT). The Quebec strains consisted of 3 isolates before 1993 and 10 isolates from 1993. In the PLA assay, we compared 2 different fixatives, acetone and formalin. Acetone-fixation allowed us to identify 6 groups from amongst the viruses tested. All the Quebec isolates were different from the reference strains. In addition, antigenic variation was detected between Quebec isolates obtained before and during 1993. However, PLA assays performed after formalin fixation did not detect these antigenic variations. Neutralization tests were carried out with 2 polyclonal antibodies (PAb) and 6 monoclonal antibodies (MAb). They were used to classify BVDV strains and isolates into 4 groups and 7 subgroups respectively. In conclusion, we demonstrated that the BVDV isolates from the 1993 outbreak in Quebec are antigenically different from reference strains and from isolates existing in Quebec before 1993. In addition, we have shown that 2 internationally used fixation-methods in PLA assay give different results. The usefulness of each method is discussed. PMID:9008798

  13. Contrasting ET-retrieval methods from remote sensing in a semiarid area (Southern Spain)

    NASA Astrophysics Data System (ADS)

    Martínez, José Angel; García Galiano, Sandra G.; Baille, Alain

    2013-04-01

    The study area of Campo de Cartagena, is located in the Segura River basin (South-East of Spain). This basin is characterized by strong climatic contrasts, frequent droughts and floods. These contrasts, in addition to the progressive increase in water demands associated with economic activities, land use and climate change, contribute to frequent water deficit situations. For these reasons, an important component in the energy and water balance is the evapotranspiration, particularly in these semi-arid areas where water deficiency is a major problem for the economic and sustainable welfare. Through interpretation of remote sensing data, applied to the Segura River Basin, indices and parameters establishing statistical relationships are identified: albedo, normalized difference vegetation index (NDVI), land surface emissivity and temperature (LST), and actual evapotranspiration (ET), among other variables. The proposed methodology allows the operational estimation of ET from Landsat-5 TM, for wide areas. Several corrections (radiometric and atmospheric) and cloud masks, were applied to the images. By incorporating a Digital Elevation Model (DEM) and topographical attributes, the spatial distribution of instantaneous ET (at satellite overpass) was derived considering a topographical correction of shortwave net radiation. Two residual algorithms were considered for retrieving ET: (i) a single-source model, based on the direct estimation of the evaporative fraction from the analysis of NDVI-LST space, and (ii) a dual-source model, named 'revised three temperature model' (3T-R model). The results from both methods were validated with flux towers observations at satellite overpass and at daily scale (24h). The two residual methods had low requirement of input data, making easier the operational assessment and implementation of ET mapping tools over large areas. The information below a GIS environment will allow the identification of spatiotemporal patterns of water

  14. Method for utilizing properties of the sinc(x) function for phase retrieval on nyquist-under-sampled data

    NASA Technical Reports Server (NTRS)

    Dean, Bruce H. (Inventor); Smith, Jeffrey Scott (Inventor); Aronstein, David L. (Inventor)

    2012-01-01

    Disclosed herein are systems, methods, and non-transitory computer-readable storage media for simulating propagation of an electromagnetic field, performing phase retrieval, or sampling a band-limited function. A system practicing the method generates transformed data using a discrete Fourier transform which samples a band-limited function f(x) without interpolating or modifying received data associated with the function f(x), wherein an interval between repeated copies in a periodic extension of the function f(x) obtained from the discrete Fourier transform is associated with a sampling ratio Q, defined as a ratio of a sampling frequency to a band-limited frequency, and wherein Q is assigned a value between 1 and 2 such that substantially no aliasing occurs in the transformed data, and retrieves a phase in the received data based on the transformed data, wherein the phase is used as feedback to an optical system.

  15. Equipotent generation of protective antitumor immunity by various methods of dendritic cell loading with whole cell tumor antigens.

    PubMed

    Lambert, L A; Gibson, G R; Maloney, M; Barth, R J

    2001-01-01

    Multiple clinically applicable methods have been used to induce dendritic cells (DCs) to express whole cell tumor antigens, including pulsing DCs with tumor lysate, and mixing DCs with apoptotic or live tumor cells. Herein we demonstrate, using two different tumor systems, that these methods are equipotent inducers of systemic antitumor immunity. Furthermore, tumor lysate pulsed DC vaccines generate more potent antitumor immunity than immunization with irradiated tumor cells plus the classic adjuvant, Corynebacterium parvum. PMID:11394500

  16. A single field of view method for retrieving tropospheric temperature profiles from cloud-contaminated radiance data

    NASA Technical Reports Server (NTRS)

    Hodges, D. B.; Scoggins, J. R.

    1977-01-01

    The paper presents a method for retrieving single field of view tropospheric temperature profiles directly from cloud-contaminated radiance data through the use of auxiliary data such as observed shelter temperatures and estimated cloud-top height. A model was formulated to calculate cloud parameters for use with the radiative transport equation at an estimated cloud-top level. The cloud and temperature data are used in conjunction with real and simulated radiance data from NOAA satellites.

  17. Sucrose density gradient centrifugation and cross-flow filtration methods for the production of arbovirus antigens inactivated by binary ethylenimine

    PubMed Central

    Pyke, Alyssa T; Phillips, Debra A; Chuan, Teck F; Smith, Greg A

    2004-01-01

    Background Sucrose density gradient centrifugation and cross-flow filtration methods have been developed and standardised for the safe and reproducible production of inactivated arbovirus antigens which are appropriate for use in diagnostic serological applications. Methods To optimise the maximum titre of growth during the propagation of arboviruses, the multiplicity of infection and choice of cell line were investigated using stocks of Ross River virus and Barmah Forest virus grown in both mosquito and mammalian cell lines. To standardise and improve the efficacy of the inactivation of arboviral suspensions, stocks of Ross River virus, Barmah Forest virus, Japanese encephalitis virus, Murray Valley encephalitis virus and Alfuy virus were chemically inactivated using binary ethylenimine at a final concentration of 3 mM. Aliquots were then taken at hourly intervals and crude inactivation rates were determined for each virus using a plaque assay. To ensure complete inactivation, the same aliquots were each passaged 3 times in Aedes albopictus C6/36 cells and the presence of viral growth was detected using an immunofluorescent assay. For larger quantities of viral suspensions, centrifugation on an isopycnic sucrose density gradient or cross-flow filtration was used to produce concentrated, pure antigens or partially concentrated, semi-purified antigens respectively. Results The results of the propagation experiments suggested that the maximum viral titres obtained for both Ross River virus and Barmah Forest virus were affected by the incubation period and choice of cell line, rather than the use of different multiplicity of infection values. Results of the binary ethylenimine inactivation trial suggested that standardised periods of 5 or 8 hours would be suitable to ensure effective and complete inactivation for a number of different arboviral antigens. Conclusion Two methods used to prepare inactivated arbovirus antigens have been standardised to minimise production

  18. Enzyme-labeled Antigen Method: Development and Application of the Novel Approach for Identifying Plasma Cells Locally Producing Disease-specific Antibodies in Inflammatory Lesions

    PubMed Central

    Mizutani, Yasuyoshi; Shiogama, Kazuya; Onouchi, Takanori; Sakurai, Kouhei; Inada, Ken-ichi; Tsutsumi, Yutaka

    2016-01-01

    In chronic inflammatory lesions of autoimmune and infectious diseases, plasma cells are frequently observed. Antigens recognized by antibodies produced by the plasma cells mostly remain unclear. A new technique identifying these corresponding antigens may give us a breakthrough for understanding the disease from a pathophysiological viewpoint, simply because the immunocytes are seen within the lesion. We have developed an enzyme-labeled antigen method for microscopic identification of the antigen recognized by specific antibodies locally produced in plasma cells in inflammatory lesions. Firstly, target biotinylated antigens were constructed by the wheat germ cell-free protein synthesis system or through chemical biotinylation. Next, proteins reactive to antibodies in tissue extracts were screened and antibody titers were evaluated by the AlphaScreen method. Finally, with the enzyme-labeled antigen method using the biotinylated antigens as probes, plasma cells producing specific antibodies were microscopically localized in fixed frozen sections. Our novel approach visualized tissue plasma cells that produced 1) autoantibodies in rheumatoid arthritis, 2) antibodies against major antigens of Porphyromonas gingivalis in periodontitis or radicular cyst, and 3) antibodies against a carbohydrate antigen, Strep A, of Streptococcus pyogenes in recurrent tonsillitis. Evaluation of local specific antibody responses expectedly contributes to clarifying previously unknown processes in inflammatory disorders. PMID:27006517

  19. An inversion method for retrieving soil moisture information from satellite altimetry observations

    NASA Astrophysics Data System (ADS)

    Uebbing, Bernd; Forootan, Ehsan; Kusche, Jürgen; Braakmann-Folgmann, Anne

    2016-04-01

    Soil moisture represents an important component of the terrestrial water cycle that controls., evapotranspiration and vegetation growth. Consequently, knowledge on soil moisture variability is essential to understand the interactions between land and atmosphere. Yet, terrestrial measurements are sparse and their information content is limited due to the large spatial variability of soil moisture. Therefore, over the last two decades, several active and passive radar and satellite missions such as ERS/SCAT, AMSR, SMOS or SMAP have been providing backscatter information that can be used to estimate surface conditions including soil moisture which is proportional to the dielectric constant of the upper (few cm) soil layers . Another source of soil moisture information are satellite radar altimeters, originally designed to measure sea surface height over the oceans. Measurements of Jason-1/2 (Ku- and C-Band) or Envisat (Ku- and S-Band) nadir radar backscatter provide high-resolution along-track information (~ 300m along-track resolution) on backscatter every ~10 days (Jason-1/2) or ~35 days (Envisat). Recent studies found good correlation between backscatter and soil moisture in upper layers, especially in arid and semi-arid regions, indicating the potential of satellite altimetry both to reconstruct and to monitor soil moisture variability. However, measuring soil moisture using altimetry has some drawbacks that include: (1) the noisy behavior of the altimetry-derived backscatter (due to e.g., existence of surface water in the radar foot-print), (2) the strong assumptions for converting altimetry backscatters to the soil moisture storage changes, and (3) the need for interpolating between the tracks. In this study, we suggest a new inversion framework that allows to retrieve soil moisture information from along-track Jason-2 and Envisat satellite altimetry data, and we test this scheme over the Australian arid and semi-arid regions. Our method consists of: (i

  20. A Sense Retrieving Method from a Noun for the Commonsense Feeling Judgment System

    NASA Astrophysics Data System (ADS)

    Watabe, Hirokazu; Horiguchi, Atsushi; Kawaoka, Tsukasa

    When we humans receive uncertain information, we interpret it properly, so we can expand the conversation, and take proper actions. This is possible because we have "commonsense" concerning the word, which is built up from knowledge that is stored through long time experience. Among the commonsense we use in our every day lives it is thought that there are the commonsense concerning; quantity such as size, weight, speed, time, or place; sense or feeling such as hot, beautiful, or loud; and moreover emotion such as happy or sad. In order for computers to understand the meaning and become closer to human beings, it is thought that the construction of a "Commonsense Judgment System" which deals with these "commonsense" is necessary. A subsystem needed for the "Commonsense Judgment System" is the system that judges the commonsense concerning the characteristics of words, namely the "Commonsense Feeling Judgment System." This paper proposes a mechanism to associate the characteristics of a word based on our five senses, such as an apple is red, with a knowledge base consisting of basic words. When aiming to realize this "Commonsense Feeling Judgment System" and trying to make a computer have the same commonsense and judgment ability as human beings, a very important factor is the handling of unknown words. Judgment concerning words, which are given to the computer as knowledge before hand, is not a problem since it can refer to that knowledge. But when an unknown word, non-registered knowledge, is inputted, how to process that word is a very difficult problem. In this paper, a method of unknown word processing, which connects an inputted unknown word to a word that is registered in the judgment knowledge base, is proposed. By using a concept base, which is made from several electric dictionaries, the closeness of meaning is put into consideration. With this process, it is possible to understand a word that does not exist in the knowledge base. This study aims to

  1. Novel methods for expression of foreign antigens in live vector vaccines

    PubMed Central

    Wang, Jin Yuan; Harley, Regina H.; Galen, James E.

    2013-01-01

    Bacterial live vector vaccines represent a vaccine development strategy that offers exceptional flexibility. In this approach, genes encoding protective antigens of unrelated bacterial, viral or parasitic pathogens are expressed in an attenuated bacterial vaccine strain that delivers these foreign antigens to the immune system, thereby eliciting relevant immune responses. Rather than expressing these antigens using low copy expression plasmids, here we pursue expression of foreign proteins from the live vector chromosome. Our strategy is designed to compensate for the inherent disadvantage of loss of gene dosage (vs. plasmid-based expression) by integrating antigen-encoding gene cassettes into multiple chromosomal sites already inactivated in an attenuated Salmonella enterica serovar Typhi vaccine candidate. We tested expression of a cassette encoding the green fluorescent protein (GFPuv) integrated separately into native guaBA, htrA or clyA chromosomal loci. Using single integrations, we show that expression levels of GFPuv are significantly affected by the site of integration, regardless of the inclusion of additional strong promoters within the incoming cassette. Using cassettes integrated into both guaBA and htrA, we observe cumulative synthesis levels from two integration sites superior to single integrations. Most importantly, we observe that GFPuv expression increases in a growth phase-dependent manner, suggesting that foreign antigen synthesis may be “tuned” to the physiology of the live vaccine. We expect this novel platform expression technology to prove invaluable in the development of a wide variety of multivalent live vector vaccines, capable of expressing multiple antigens from both chromosomal and plasmid-based expression systems within a single strain. PMID:23406777

  2. A single field of view method for retrieving tropospheric temperature profiles from cloud-contaminated radiance data

    NASA Technical Reports Server (NTRS)

    Hodges, D. B.

    1976-01-01

    An iterative method is presented to retrieve single field of view (FOV) tropospheric temperature profiles directly from cloud-contaminated radiance data. A well-defined temperature profile may be calculated from the radiative transfer equation (RTE) for a partly cloudy atmosphere when the average fractional cloud amount and cloud-top height for the FOV are known. A cloud model is formulated to calculate the fractional cloud amount from an estimated cloud-top height. The method is then examined through use of simulated radiance data calculated through vertical integration of the RTE for a partly cloudy atmosphere using known values of cloud-top height(s) and fractional cloud amount(s). Temperature profiles are retrieved from the simulated data assuming various errors in the cloud parameters. Temperature profiles are retrieved from NOAA-4 satellite-measured radiance data obtained over an area dominated by an active cold front and with considerable cloud cover and compared with radiosonde data. The effects of using various guessed profiles and the number of iterations are considered.

  3. De-noising and retrieving algorithm of Mie lidar data based on the particle filter and the Fernald method.

    PubMed

    Li, Chen; Pan, Zengxin; Mao, Feiyue; Gong, Wei; Chen, Shihua; Min, Qilong

    2015-10-01

    The signal-to-noise ratio (SNR) of an atmospheric lidar decreases rapidly as range increases, so that maintaining high accuracy when retrieving lidar data at the far end is difficult. To avoid this problem, many de-noising algorithms have been developed; in particular, an effective de-noising algorithm has been proposed to simultaneously retrieve lidar data and obtain a de-noised signal by combining the ensemble Kalman filter (EnKF) and the Fernald method. This algorithm enhances the retrieval accuracy and effective measure range of a lidar based on the Fernald method, but sometimes leads to a shift (bias) in the near range as a result of the over-smoothing caused by the EnKF. This study proposes a new scheme that avoids this phenomenon using a particle filter (PF) instead of the EnKF in the de-noising algorithm. Synthetic experiments show that the PF performs better than the EnKF and Fernald methods. The root mean square error of PF are 52.55% and 38.14% of that of the Fernald and EnKF methods, and PF increases the SNR by 44.36% and 11.57% of that of the Fernald and EnKF methods, respectively. For experiments with real signals, the relative bias of the EnKF is 5.72%, which is reduced to 2.15% by the PF in the near range. Furthermore, the suppression impact on the random noise in the far range is also made significant via the PF. An extensive application of the PF method can be useful in determining the local and global properties of aerosols.

  4. Information storage medium and method of recording and retrieving information thereon

    DOEpatents

    Marchant, D. D.; Begej, Stefan

    1986-01-01

    Information storage medium comprising a semiconductor doped with first and second impurities or dopants. Preferably, one of the impurities is introduced by ion implantation. Conductive electrodes are photolithographically formed on the surface of the medium. Information is recorded on the medium by selectively applying a focused laser beam to discrete regions of the medium surface so as to anneal discrete regions of the medium containing lattice defects introduced by the ion-implanted impurity. Information is retrieved from the storage medium by applying a focused laser beam to annealed and non-annealed regions so as to produce a photovoltaic signal at each region.

  5. New Term Weighting Formulas for the Vector Space Method in Information Retrieval

    SciTech Connect

    Chisholm, E.; Kolda, T.G.

    1999-03-01

    The goal in information retrieval is to enable users to automatically and accurately find data relevant to their queries. One possible approach to this problem i use the vector space model, which models documents and queries as vectors in the term space. The components of the vectors are determined by the term weighting scheme, a function of the frequencies of the terms in the document or query as well as throughout the collection. We discuss popular term weighting schemes and present several new schemes that offer improved performance.

  6. A reliable method for avoiding false negative results with Luminex single antigen beads; evidence of the prozone effect.

    PubMed

    Carey, B Sean; Boswijk, Kim; Mabrok, Mazen; Rowe, Peter A; Connor, Andrew; Saif, Imran; Poles, Anthony

    2016-07-01

    Luminex single antigen bead (SAB) assays have become an essential tool in monitoring the status of antibody to the Human Leucocyte Antigen (HLA) of patients both before and after transplantation. In addition SAB data is used to aid risk stratification to assess immunological risk of humoral rejection in solid organ transplantation (CTAG/BTAG guidelines) [1]. Increasingly laboratories are reporting false negative results at high antibody titre due to a prozone effect. Here we report a case study where the prozone effect led to a false negative antibody result that could have resulted in adverse outcome. We describe a method to reliably remove the prozone effect through heat inactivation and the addition of Ethylenediaminetetraacetic acid (EDTA) to the Luminex wash buffer. PMID:27109036

  7. Measurements of formaldehyde total content using DOAS technique: a new retrieval method for overcast

    NASA Astrophysics Data System (ADS)

    Postylyakov, Oleg; Borovski, Alexander

    2014-11-01

    Formaldehyde (HCHO) is a significant constituent of the atmospheric chemistry involved in a lot of chemical reactions, which principal global source is the intermediate oxidation of volatile organic compounds (VOCs). Taking into account that HCHO basically undergo by photolysis and reaction with hydroxyl radical within a few hours, isoprene together with other short-lived VOCs and direct HCHO emissions can cause local HCHO enhancement over certain areas, and, hence, cases with HCHO, that exceed some background level, can be examined as local pollution of the atmosphere by VOCs. HCHO has significant specific features in spectral structure of UV absorption cross-section to be measured using the differential optical absorption spectroscopy (DOAS) technique. Several retrieval algorithms applicable for DOAS measurements in cloudless were previously developed. A new algorithm applicable for overcast and cloudless sky and its error analysis is briefly presented in this paper. In case we know the cloud base height, but don't know cloud optical depth, the error of HCHO total content retrieval is about 10-20% for winter season, about 5% for summer season, and about 30-40% for transition season when the ABL is below the cloud base. In case we know both the cloud base height and cloud optical depth, the error is about 5-10% for winter season, less than 5% for summer season, and about 25-35% for transition season when the ABL is below the cloud base. The errors dramatically increase when clouds penetrate into ABL in both cases.

  8. A Practical Method for Retrieving Land Surface Temperature from AMSR-E over the Amazon Forest

    NASA Astrophysics Data System (ADS)

    Gao, H.; Fu, R.; Dickinson, R.; Negrón Juárez, R. I.

    2007-12-01

    Remote sensing of land surface temperature (LST) using infrared sensors, such as the Moderate Resolution Imaging Spectroradiometer (MODIS), is only capable of retrieval under clear-sky conditions. Such LST observations over tropical forests are very limited due to clouds and rainfall, especially during the wet season, and high atmospheric water vapor content. In comparison, low frequency microwave radiances are minimally influenced by meteorological conditions. Exploring this advantage, we have developed an algorithm to retrieve LST over the Amazonian forest. The algorithm uses multi-frequency polarized microwave brightness temperatures from the Advanced Microwave Scanning Radiometer (AMSR-E) on NASA's Earth Observing System. Relationships between polarization ratio and surface emissivity are established for forested and non-forested areas, such that LST can be calculated solely from microwave radiance. Results are presented over three time scales: at each orbit, daily, and monthly. Results are evaluated by comparing with available air temperature records on daily and monthly intervals. Our findings indicate that the AMSR-E derived LST agrees well with in situ measurements. Results during the wet season over the tropical forest suggest that AMSR-E LST is robust under all-weather conditions and shows higher correlation to meteorological data (r=0.70) than infrared based LST approaches (r=0.42).

  9. Idea Retrieval.

    ERIC Educational Resources Information Center

    Shively, Daniel

    1988-01-01

    Discusses the need to retrieve ideas in addition to content retrieval by such means as classification, subject headings, and keywords. Three models for idea retrieval are described, and a new model is proposed which combines selection, a controlled vocabulary, and logical structure. (seven references) (CLB)

  10. An improved tropospheric ozone database retrieved from SCIAMACHY Limb-Nadir-Matching method

    NASA Astrophysics Data System (ADS)

    Jia, Jia; Rozanov, Alexei; Ladstätter-Weißenmayer, Annette; Ebojie, Felix; Rahpoe, Nabiz; Bötel, Stefan; Burrows, John

    2015-04-01

    Tropospheric ozone is one of the most important green-house gases and the main component of photochemical smog. It is either transported from the stratosphere or photochemically produced during pollution events in the troposphere that threaten the respiratory system. To investigate sources, transport mechanisms of tropospheric ozone in a global view, limb nadir matching (LNM) technique applied with SCIAMACHY instrument is used to retrieve tropospheric ozone. With the fact that 90% ozone is located in the stratosphere and only about 10% can be observed in the troposphere, the usage of satellite data requires highly qualified nadir and limb data. In this study we show an improvement of SCIAMACHY limb data as well as its influence on tropospheric ozone results. The limb nadir matching technique is also refined to increase the quality of the tropospheric ozone. The results are validated with ozone sonde measurements.

  11. A method to retrieve super-thin cloud optical depth over ocean background with polarized sunlight

    NASA Astrophysics Data System (ADS)

    Sun, W.; Baize, R. R.; Videen, G.; Hu, Y.; Fu, Q.

    2015-10-01

    In this work, an algorithm that uses the polarization angle of the backscattered solar radiation to detect clouds with optical depth (OD) < ~ 0.3 is further developed. We find that at viewing angles within ± ∼ 8° around the backscattering direction, the p-polarized intensity that is parallel to the meridian plane of reflected light from the surface is sensitive to, and nearly linearly related to, the optical depth of super-thin clouds. Moreover, our sensitivity study suggests that the p-polarized intensity at these viewing angles is not sensitive to the ocean surface conditions. Using this property of p-polarized intensity, super-thin clouds' optical depth can be retrieved.

  12. Hybrid regularization method for the ill-posed inversion of multiwavelength lidar data in the retrieval of aerosol size distributions.

    PubMed

    Böckmann, C

    2001-03-20

    A specially developed method is proposed to retrieve the particle volume distribution, the mean refractive index, and other important physical parameters, e.g., the effective radius, volume, surface area, and number concentrations of tropospheric and stratospheric aerosols, from optical data by use of multiple wavelengths. This algorithm requires neither a priori knowledge of the analytical shape of the distribution nor an initial guess of the distribution. As a result, even bimodal and multimodal distributions can be retrieved without any advance knowledge of the number of modes. The nonlinear ill-posed inversion is achieved by means of a hybrid method combining regularization by discretization, variable higher-order B-spline functions and a truncated singular-value decomposition. The method can be used to handle different lidar devices that work with various values and numbers of wavelengths. It is shown, to my knowledge for the first time, that only one extinction and three backscatter coefficients are sufficient for the solution. Moreover, measurement errors up to 20% are allowed. This result could be achieved by a judicious fusion of different properties of three suitable regularization parameters. Finally, numerical results with an additional unknown refractive index show the possibility of successfully recovering both unknowns simultaneously from the lidar data: the aerosol volume distribution and the refractive index.

  13. Application of the Markov Chain Monte Carlo method for snow water equivalent retrieval based on passive microwave measurements

    NASA Astrophysics Data System (ADS)

    Pan, J.; Durand, M. T.; Vanderjagt, B. J.

    2015-12-01

    Markov Chain Monte Carlo (MCMC) method is a retrieval algorithm based on Bayes' rule, which starts from an initial state of snow/soil parameters, and updates it to a series of new states by comparing the posterior probability of simulated snow microwave signals before and after each time of random walk. It is a realization of the Bayes' rule, which gives an approximation to the probability of the snow/soil parameters in condition of the measured microwave TB signals at different bands. Although this method could solve all snow parameters including depth, density, snow grain size and temperature at the same time, it still needs prior information of these parameters for posterior probability calculation. How the priors will influence the SWE retrieval is a big concern. Therefore, in this paper at first, a sensitivity test will be carried out to study how accurate the snow emission models and how explicit the snow priors need to be to maintain the SWE error within certain amount. The synthetic TB simulated from the measured snow properties plus a 2-K observation error will be used for this purpose. It aims to provide a guidance on the MCMC application under different circumstances. Later, the method will be used for the snowpits at different sites, including Sodankyla, Finland, Churchill, Canada and Colorado, USA, using the measured TB from ground-based radiometers at different bands. Based on the previous work, the error in these practical cases will be studied, and the error sources will be separated and quantified.

  14. Trace gas retrieval for limb DOAS under changing atmospheric conditions: The X-gas scaling method vs optimal estimation

    NASA Astrophysics Data System (ADS)

    Hueneke, Tilman; Grossmann, Katja; Knecht, Matthias; Raecke, Rasmus; Stutz, Jochen; Werner, Bodo; Pfeilsticker, Klaus

    2016-04-01

    Changing atmospheric conditions during DOAS measurements from fast moving aircraft platforms pose a challenge for trace gas retrievals. Traditional inversion techniques to retrieve trace gas concentrations from limb scattered UV/vis spectroscopy, like optimal estimation, require a-priori information on Mie extinction (e.g., aerosol concentration and cloud cover) and albedo, which determine the atmospheric radiative transfer. In contrast to satellite applications, cloud filters can not be applied because they would strongly reduce the usable amount of expensively gathered measurement data. In contrast to ground-based MAX-DOAS applications, an aerosol retrieval based on O4 is not able to constrain the radiative transfer in air-borne applications due to the rapidly decreasing amount of O4 with altitude. Furthermore, the assumption of a constant cloud cover is not valid for fast moving aircrafts, thus requiring 2D or even 3D treatment of the radiative transfer. Therefore, traditional techniques are not applicable for most of the data gathered by fast moving aircraft platforms. In order to circumvent these limitations, we have been developing the so-called X-gas scaling method. By utilising a proxy gas X (e.g. O3, O4, …), whose concentration is either a priori known or simultaneously in-situ measured as well as remotely measured, an effective absorption length for the target gas is inferred. In this presentation, we discuss the strengths and weaknesses of the novel approach along with some sample cases. A particular strength of the X-gas scaling method is its insensitivity towards the aerosol abundance and cloud cover as well as wavelength dependent effects, whereas its sensitivity towards the profiles of both gases requires a priori information on their shapes.

  15. Retrieval of Sea-Bed Parameters by the Method of Matching Acoustic Fields on the Basis of Vertical Angular Spectra

    NASA Astrophysics Data System (ADS)

    Kerzhakov, B. V.; Kulinich, V. V.

    2016-08-01

    We use the field matching method to solve the inverse problem of estimating the geoacoustic parameters of a stratified sea bed using the objective function based on the norm of difference between the experimental and simulated vertical angular spectra of the acoustic field and combination of the rapid-annealing method with direct search methods for localization of the global minimum of the objective function. To reduce the influence of the ravine effects of the objective function, we use regularization on the basis of mutual correlations of the experimental and simulated vertical angular spectra of the acoustic field. The numerical experiment has been performed to retrieve the parameters of the model waveguide, e.g., the thickness of the water layer and the layer of sediments, the velocity and attenuation coefficients of longitudinal waves, and the density of the sediment layer and the subjacent half-space in the presence of noise interference of different intensity levels.

  16. New method for isolating barophiles from intestinal contents of deep-sea fishes retrieved from the abyssal zone.

    PubMed

    Nakayama, A; Yano, Y; Yoshida, K

    1994-11-01

    We devised a new method (the dorayaki method) using marine agar under in situ pressures to isolate barophilic bacteria from the intestinal contents of three deep-sea fishes (two Coryphaenoides yaquinae samples and one Ilyophis sp. sample) retrieved from depths of 4,700 to 6,100 m in the Northwest Pacific Ocean. All 10 strains isolated from one sample (C. yaquinae) were obligately barophilic. One of the 10 strains did not grow at atmospheric pressure and 103.4 MPa but did grow well between 20.7 and 82.7 MPa, with optimal growth at 41.4 MPa. This method is useful for isolating psychrophilic and barophilic deep-sea bacteria. PMID:16349450

  17. Human factors analysis and design methods for nuclear waste retrieval systems. Human factors design methodology and integration plan

    SciTech Connect

    Casey, S.M.

    1980-06-01

    The purpose of this document is to provide an overview of the recommended activities and methods to be employed by a team of human factors engineers during the development of a nuclear waste retrieval system. This system, as it is presently conceptualized, is intended to be used for the removal of storage canisters (each canister containing a spent fuel rod assembly) located in an underground salt bed depository. This document, and the others in this series, have been developed for the purpose of implementing human factors engineering principles during the design and construction of the retrieval system facilities and equipment. The methodology presented has been structured around a basic systems development effort involving preliminary development, equipment development, personnel subsystem development, and operational test and evaluation. Within each of these phases, the recommended activities of the human engineering team have been stated, along with descriptions of the human factors engineering design techniques applicable to the specific design issues. Explicit examples of how the techniques might be used in the analysis of human tasks and equipment required in the removal of spent fuel canisters have been provided. Only those techniques having possible relevance to the design of the waste retrieval system have been reviewed. This document is intended to provide the framework for integrating human engineering with the rest of the system development effort. The activities and methodologies reviewed in this document have been discussed in the general order in which they will occur, although the time frame (the total duration of the development program in years and months) in which they should be performed has not been discussed.

  18. [METHODS FOR DETECTION OF ANTIBODIES TO HLA ANTIGENS IN PATIENTS AWAITING KIDNEY TRANSPLANTATION AND COMBINED PANCREAS-KIDNEY TRANSPLANTATION].

    PubMed

    Ančić, Mirela; Maravić, Blaženko; Radman, Maja; Kovačić, Vedran

    2014-12-01

    The best possibility to treat chronic renal disease is renal transplantation. Especially important fact in transplantation is the percentage of so-called panel reactive antibody (PRA) that is focused on the human leukocyte antigen. There are several methods to determine the percentage of PRA in sensitized patients awaiting kidney transplants. The most important is the complement-dependent cytotoxicity. A higher value of PRA implies greater likelihood of positive cross-match with random donor and lower probability of receiving a transplant. Comparing the sensitivity of laboratory tests for determination of PRA percentage in patient serum, it is concluded that ELISA and flow cytometry proved to be more sensitive and specific.

  19. Application of Rough Sets to Information Retrieval.

    ERIC Educational Resources Information Center

    Miyamoto, Sadaaki

    1998-01-01

    Develops a method of rough retrieval, an application of the rough set theory to information retrieval. The aim is to: (1) show that rough sets are naturally applied to information retrieval in which categorized information structure is used; and (2) show that a fuzzy retrieval scheme is induced from the rough retrieval. (AEF)

  20. Phase retrieval and time-frequency methods in the measurement of ultrashort laser pulses

    SciTech Connect

    DeLong, K.W.; Fittinghoff, D.N.; Ladera, C.L.; Trebino, R.

    1995-02-01

    Recently several techniques have become available to measure the time- (or frequency-) dependent intensity and phase of ultrashort laser pulses. One of these, Frequency-Resolved Optical Gating (FROG), is rigorous and has achieved single-laser-shot operation. FROG combines the concepts of time-frequency analysis in the form of spectrogram generation (in order to create a two-dimensional problem), and uses a phase-retrieval-based algorithm to invert the experimental data to yield the intensity and phase of the laboratory laser pulse. In FROG it is easy to generate a spectrogram of the unknown signal, and inversion of the spectrogram to recover the signal is the main goal. Because the temporal width of a femtosecond laser pulse is much shorter than anything achievable by electronics, FROG uses the pulse to measure itself. In FROG, the laser pulse is split into two replicas of itself by a partially reflecting beamsplitter, and the two replicas interact with each other in a medium with an instantaneous nonlinear-optical response. This interaction generates a signal field that is then frequency-resolved using a spectrometer. The spectrum of the signal field is measured for all relevant values of the temporal delay between the two pulses. Here, the authors employ FROG and FROG related techniques to measure the time-dependent intensity and phase of an ultrashort laser pulse.

  1. Effects of histoplasmin M antigen chemical and enzymatic deglycosylation on cross-reactivity in the enzyme-linked immunoelectrotransfer blot method.

    PubMed Central

    Zancopé-Oliveira, R M; Bragg, S L; Reiss, E; Wanke, B; Peralta, J M

    1994-01-01

    The enzyme-linked immunoelectrotransfer blot (EITB) method was evaluated as a suitable method for detecting antibodies against M antigen of Histoplasma capsulatum by use of both glycosylated and deglycosylated M protein of histoplasmin (HMIN). Sera from patients with histoplasmosis, paracoccidioidomycosis, blastomycosis, coccidioidomycosis, and aspergillosis were tested by the EITB with glycosylated M protein of HMIN. This assay demonstrated 100% sensitivity with histoplasmosis serum samples, all of which reacted with the 94-kDa glycoprotein (M antigen). Although the EITB is highly sensitive, it is not specific for histoplasmosis when glycosylated M protein is used as an antigen. A total of 81% of paracoccidioidomycosis, 25% of blastomycosis, 33% of coccidioidomycosis, 73% of aspergillosis, and 16% of tuberculosis serum samples cross-reacted with M protein of HMIN and yielded patterns indistinguishable from those obtained with histoplasmosis serum samples. The EITB reactions with both untreated M antigen and M antigen altered by periodate oxidation or by deglycosylation with endoglycosidases were compared. Cross-reactions with heterologous sera in the EITB could be attributed to periodate-sensitive carbohydrate epitopes, as reflected by the increase in the test specificity from 46.1 to 91.2% after periodate treatment of M protein. The EITB for the detection of antibodies to M antigen is a potential diagnostic test for histoplasmosis, provided that periodate-treated M protein is used as an antigen. Images PMID:8556474

  2. A Comparison Between Heliosat-2 and Artificial Neural Network Methods for Global Horizontal Irradiance Retrievals over Desert Environments

    NASA Astrophysics Data System (ADS)

    Ghedira, H.; Eissa, Y.

    2012-12-01

    Global horizontal irradiance (GHI) retrievals at the surface of any given location could be used for preliminary solar resource assessments. More accurately, the direct normal irradiance (DNI) and diffuse horizontal irradiance (DHI) are also required to estimate the global tilt irradiance, mainly used for fixed flat plate collectors. Two different satellite-based models for solar irradiance retrievals have been applied over the desert environment of the United Arab Emirates (UAE). Both models employ channels of the SEVIRI instrument, onboard the geostationary satellite Meteosat Second Generation, as their main inputs. The satellite images used in this study have a temporal resolution of 15-min and a spatial resolution of 3-km. The objective of this study is to compare between the GHI retrieved using the Heliosat-2 method and an artificial neural network (ANN) ensemble method over the UAE. The high-resolution visible channel of SEVIRI is used in the Heliosat-2 method to derive the cloud index. The cloud index is then used to compute the cloud transmission, while the cloud-free GHI is computed from the Linke turbidity factor. The product of the cloud transmission and the cloud-free GHI denotes the estimated GHI. A constant underestimation is observed in the estimated GHI over the dataset available in the UAE. Therefore, the cloud-free DHI equation in the model was recalibrated to fix the bias. After recalibration, results over the UAE show a root mean square error (RMSE) value of 10.1% and a mean bias error (MBE) of -0.5%. As for the ANN approach, six thermal channels of SEVIRI were used to estimate the DHI and the total optical depth of the atmosphere (δ). An ensemble approach is employed to obtain a better generalizability of the results, as opposed to using one single weak network. The DNI is then computed from the estimated δ using the Beer-Bouguer-Lambert law. The GHI is computed from the DNI and DHI estimates. The RMSE for the estimated GHI obtained over an

  3. A 3D shape retrieval method for orthogonal fringe projection based on a combination of variational image decomposition and variational mode decomposition

    NASA Astrophysics Data System (ADS)

    Li, Biyuan; Tang, Chen; Zhu, Xinjun; Chen, Xia; Su, Yonggang; Cai, Yuanxue

    2016-11-01

    The orthogonal fringe projection technique has as wide as long practical application nowadays. In this paper, we propose a 3D shape retrieval method for orthogonal composite fringe projection based on a combination of variational image decomposition (VID) and variational mode decomposition (VMD). We propose a new image decomposition model to extract the orthogonal fringe. Then we introduce the VMD method to separate the horizontal and vertical fringe from the orthogonal fringe. Lastly, the 3D shape information is obtained by the differential 3D shape retrieval method (D3D). We test the proposed method on a simulated pattern and two actual objects with edges or abrupt changes in height, and compare with the recent, related and advanced differential 3D shape retrieval method (D3D) in terms of both quantitative evaluation and visual quality. The experimental results have demonstrated the validity of the proposed method.

  4. Flow cytometry-based methods for assessing soluble scFv activities and detecting pathogen antigens in solution

    SciTech Connect

    Gray, Sean; Weigel, Kris M.; Miller, Keith D.; Ndung'u, Joseph; Buscher, Philippe; Tran, Thao N.; Baird, Cheryl L.; Cangelosi, Gerard A.

    2010-04-01

    Novel methods are reported for evaluating and utilizing single chain fragment variable (scFv) antibodies derived from yeast-display libraries. Yeast-display was used to select scFv specific to invariant surface glycoproteins (ISG) of Trypanosoma brucei. A limiting step in the isolation of scFv from nonimmune libraries is the conversion of highly active yeast-displayed scFv into soluble antibodies that can be used in standard immunoassays. Challenges include limited solubility or activity following secretion and purification of scFv. For this reason, few scFv derived from yeast-display platforms have moved into development and implementation as diagnostic reagents. To address this problem, assays were developed that employ both yeastdisplayed and secreted scFv as analytical reagents. The first is a competitive inhibition flow cytometry (CIFC) assay that detects secreted scFv by virtue of its ability to competitively inhibit the binding of biotinylated antigen to yeast-displayed scFv. The second is an epitope binning assay that uses secreted scFv toidentify additional yeast-displayed scFv that bind nonoverlapping or noncompeting epitopes on an antigen. The epitope binning assay was used not only to identify sandwich assay pairs with yeast-displayed scFv, but also to identify active soluble scFv present in low concentration in a crude expression extract. Finally, a CIFC assay was developed that bypasses entirely the need for soluble scFv expression, by using yeast displayed scFv to detect unlabeled antigen in samples. These methods will facilitate the continued development and practical implementation of scFv derived from yeast-display libraries.

  5. Flow Cytometry-Based Methods for Assessing Soluble scFv Activities and Detecting Antigens in Solution

    PubMed Central

    Gray, Sean A.; Weigel, Kris M.; Miller, Keith D.; Ndung'u, Joseph; Büscher, Philippe; Tran, Thao; Baird, Cheryl; Cangelosi, Gerard A.

    2010-01-01

    Novel methods are reported for evaluating and utilizing single chain fragment variable (scFv) antibodies derived from yeast-display libraries. Yeast-display was used to select scFv specific to invariant surface glycoproteins (ISG) of Trypanosoma brucei. Alimiting step in the isolation of scFv from non-immune libraries is the conversion of highly active yeast-displayed scFv into soluble antibodies that can be used in standard immunoassays. Challenges include limited solubility or activity following secretion and purification of scFv. For this reason, few scFv derived from yeast-display platforms have moved into development and implementation as diagnostic reagents. To address this problem, assays were developed that employ both yeast-displayed and -secreted scFv as analytical reagents. The first is a competitive inhibition flow cytometry (CIFC) assay that detects secreted scFv by virtue of their ability to competitively inhibit the binding of biotinylated antigen to yeast-displayed scFv. The second is an epitope binning assay that uses secreted scFv to identify additional yeast-displayed scFv that bind non-overlapping or non-competing epitopes on an antigen. The epitope binning assay was used not only to identify sandwich assay pairs with yeast-displayed scFv, but also to identify active soluble scFv present in low concentration in a crude expression extract. Finally, a CIFC assay was developed that bypasses entirely the need for soluble scFv expression, by using yeast-displayed scFv to detect unlabeled antigen in samples. These methods will facilitate the continued development and practical implementation of scFv derived from yeast-display libraries. PMID:19953671

  6. Validation and operational application of a rapid method for rabies antigen detection.

    PubMed

    Saturday, Greg A; King, Robin; Fuhrmann, Leslie

    2009-01-01

    The Veterinary Laboratory Europe (VLE) deployed a direct, rapid immunohistochemical test (DRIT), developed by the Centers for Disease Control and Prevention (CDC), to the US military veterinary units in Iraq and Afghanistan. The test detects rabies virus antigen in fresh and frozen brainstem samples from various animal species. The goal was to conduct surveillance in 2 countries without current rabies diagnostic capabilities and little historical data on rabies prevalence. During the deployment the DRIT was evaluated, and Veterinary Corps officers and technicians were trained to operate the test. Civilian veterinarians from both Iraq and Afghanistan were organized for a lecture forum on rabies, a sample collection lab, and familiarization with the DRIT. Samples collected in Iraq and Afghanistan were tested in the field with the DRIT, and compared to the traditional laboratory standard utilizing direct fluorescent antibody testing at VLE and the CDC with 100% agreement.

  7. The limits of ultrahigh-resolution x-ray mapping: estimating uncertainties in thin-film and interface structures determined by phase retrieval methods

    SciTech Connect

    Zhou H.; Pindak R.; Clarke, R.; Steinberg, D.NM.; Yacoby, Y.

    2012-04-25

    Capturing subtle details at the sub-Angstrom level is key to understanding the structural basis of many intriguing interfacial phenomena in epitaxial thin films and nanostructures. X-ray phase retrieval methods are ideally suited to this task but the usual approaches for determination of uncertainties, based on refining a parametrized model, are not applicable in this case. Here we describe a method to estimate the uncertainties of the system electron density, obtained by phase retrieval, and of parameters of interest obtained from it. The method is based on the bootstrap approach and it can be generally applied to surface x-ray scattering data. Several examples are given which illustrate the method's utility in determining uncertainties arising from random and systematic errors. The approach also provides a quantitative measure of the validity of structural solutions obtained by phase retrieval methods.

  8. Retrieval of Minor Species Densities From Limb Scatter Measurements By Osiris On Odin Using A Modified Onion Peeling Method

    NASA Astrophysics Data System (ADS)

    Auvinen, H.; Oikarinen, L.; Kyrölä, E.; Siiskonen, T.; Hassinen, S.; Odin Team

    The Odin satellite, which carries two instruments, OSIRIS and SMR, was launched on to a heliosyncronous orbit in February 2001. The observation time is divided between aeronomical and astronomical measurements. In aeronomy mode OSIRIS and SMR scan the limb either in a continuous or in a stepwise manner from tangent altitudes of 60 (alternatively 120 km) to 7 km. OSIRIS includes a UV-visible spectrometer and an infrared imager. SMR is a sub-millimeter radiometer, which is used for both aeronomy and astronomy measurements. In this paper we present a Modified Onion Peeling (MOP) method to retrieve mi- nor species densities from limb scatter measurements by OSIRIS. The goal is to re- trieve vertical profiles of ozone, NO2, OClO and BrO densities, and also aerosol and Rayleigh extinction. In order to relax requirements on absolute calibration the data is divided with a refer- ence measurement made at a high tangent altitude by the same instrument. Our method uses air density profiles from ECMWF as a prior. We approximate the atmosphere to be locally spherically symmetric. The method uses absolute cross sections. Multiple scattering is taken into account by pre-calculated total to single scattering radiance ratios tabulated as a function of wavelength, tangent altitude and several other rele- vant parameters. The inversion uses the whole UV-visible spectral range of OSIRIS. Several constituents are inverted simultaneously. We show first retrieval results from selected OSIRIS measurements. These results are compared against validating mea- surements. Odin is a Swedish-led satellite project funded jointly by Sweden (SNSB), Canada (CSA), Finland (Tekes) and France (CNES).

  9. [Method of traditional Chinese medicine formula design based on 3D-database pharmacophore search and patent retrieval].

    PubMed

    He, Yu-su; Sun, Zhi-yi; Zhang, Yan-ling

    2014-11-01

    By using the pharmacophore model of mineralocorticoid receptor antagonists as a starting point, the experiment stud- ies the method of traditional Chinese medicine formula design for anti-hypertensive. Pharmacophore models were generated by 3D-QSAR pharmacophore (Hypogen) program of the DS3.5, based on the training set composed of 33 mineralocorticoid receptor antagonists. The best pharmacophore model consisted of two Hydrogen-bond acceptors, three Hydrophobic and four excluded volumes. Its correlation coefficient of training set and test set, N, and CAI value were 0.9534, 0.6748, 2.878, and 1.119. According to the database screening, 1700 active compounds from 86 source plant were obtained. Because of lacking of available anti-hypertensive medi cation strategy in traditional theory, this article takes advantage of patent retrieval in world traditional medicine patent database, in order to design drug formula. Finally, two formulae was obtained for antihypertensive. PMID:25850277

  10. Methods for Retrievals of CO2 Mixing Ratios from JPL Laser Absorption Spectrometer Flights During a Summer 2011 Campaign

    NASA Technical Reports Server (NTRS)

    Menzies, Robert T.; Spiers, Gary D.; Jacob, Joseph C.

    2013-01-01

    The JPL airborne Laser Absorption Spectrometer instrument has been flown several times in the 2007-2011 time frame for the purpose of measuring CO2 mixing ratios in the lower atmosphere. This instrument employs CW laser transmitters and coherent detection receivers in the 2.05- micro m spectral region. The Integrated Path Differential Absorption (IPDA) method is used to retrieve weighted CO2 column mixing ratios. We present key features of the evolving LAS signal processing and data analysis algorithms and the calibration/validation methodology. Results from 2011 flights in various U.S. locations include observed mid-day CO2 drawdown in the Midwest and high spatial resolution plume detection during a leg downwind of the Four Corners power plant in New Mexico.

  11. IMPROVEMENT OF THE DUAL-FREQUENCY PRECIPITATION RETRIEVAL METHOD FOR A GLOBAL ESTIMATION OF THE Z-R RELATIONSHIP

    NASA Astrophysics Data System (ADS)

    Seto, Shinta; Iguchi, Toshio

    The Z-R relationship (Z=aRb) between radar reflectivity factor Z and precipitation rate R has been used for operational radar measurements, but its coefficients (a, b) are known to be highly variable in time and space and also dependent on precipitation types. The Dual-frequency Precipitation Radar (DPR) is expected to instantaneously estimate the 2-moment drop size distribution (DSD) function and to finally derive global maps of (a, b). For this big goal, it is necessary to improve the accuracy of the instantaneous dual-frequency retrieval method. In this study, Mardiana’s method (MA04) is tested with a simulated DPR measurement dataset, and it is found that MA04 has negative bias which corresponds to 40% of the true precipitation rate. While the true equivalent radar reflectivity factor Ze does not change largely along the range, the estimates of Ze by MA04 tend to be smaller at lower range bins. MA04 is modified into three new methods. In the best method, the bias is limited to 18% of the truth.

  12. Evaluation of saliva specimens as an alternative sampling method to detect hepatitis B surface antigen.

    PubMed

    Cruz, Helena Medina; da Silva, Elisangela Ferreira; Villela-Nogueira, Cristiane A; Nabuco, Letícia C; do Ó, Kycia Maria Rodrigues; Lewis-Ximenez, Lia Laura; Yoshida, Clara Fumiko Tachibana; Lampe, Elisabeth; Villar, Livia Melo

    2011-01-01

    In this study, a modified enzyme immunoassay (EIA) was evaluated for the Hepatitis B surface antigen (HBsAg) among whole saliva and oral fluid samples. Specimens were collected from 115 individuals who gave serum and oral fluid using Salivette (Sarstedt, Nümbrecht, Germany) and whole saliva. Saliva specimens were tested following a modified ELISA, and the results were compared with paired serum specimens that were tested according to the supplier's instructions. Transport buffer for the oral fluids, sample volume for assay, incubation period of sample with conjugate as well as cut-off values were evaluated to optimize the assay. The highest sensitivity and specificity were obtained by increasing the incubation of sample and conjugate to 16  hr and using the area under the receiver operating characteristic curve to calculate cut-off values. HBsAg was detected in 40 oral fluids and 44 whole saliva samples out of 47 paired positive serum specimens and not detected in 64 oral fluids and 63 whole saliva samples out of 68 matched negative sera samples by the ELISA assay. There was excellent agreement between the results for the serum and saliva specimens kappa value (κ): 0.80 for oral fluid and κ: 0.87 for whole saliva and there was excellent reproducibility. Using an optimized protocol, the sensitivities of whole saliva and oral fluid were 93.6 and 85.1%, respectively, whereas specificities of whole saliva and oral fluid were 92.6 and 94.1%, respectively. Our data showed a significant promise for the use of whole saliva and oral fluid together with the modified commercial EIA for Hepatitis B virus infection surveillance.

  13. Methods for semi-automated indexing for high precision information retrieval

    NASA Technical Reports Server (NTRS)

    Berrios, Daniel C.; Cucina, Russell J.; Fagan, Lawrence M.

    2002-01-01

    OBJECTIVE: To evaluate a new system, ISAID (Internet-based Semi-automated Indexing of Documents), and to generate textbook indexes that are more detailed and more useful to readers. DESIGN: Pilot evaluation: simple, nonrandomized trial comparing ISAID with manual indexing methods. Methods evaluation: randomized, cross-over trial comparing three versions of ISAID and usability survey. PARTICIPANTS: Pilot evaluation: two physicians. Methods evaluation: twelve physicians, each of whom used three different versions of the system for a total of 36 indexing sessions. MEASUREMENTS: Total index term tuples generated per document per minute (TPM), with and without adjustment for concordance with other subjects; inter-indexer consistency; ratings of the usability of the ISAID indexing system. RESULTS: Compared with manual methods, ISAID decreased indexing times greatly. Using three versions of ISAID, inter-indexer consistency ranged from 15% to 65% with a mean of 41%, 31%, and 40% for each of three documents. Subjects using the full version of ISAID were faster (average TPM: 5.6) and had higher rates of concordant index generation. There were substantial learning effects, despite our use of a training/run-in phase. Subjects using the full version of ISAID were much faster by the third indexing session (average TPM: 9.1). There was a statistically significant increase in three-subject concordant indexing rate using the full version of ISAID during the second indexing session (p < 0.05). SUMMARY: Users of the ISAID indexing system create complex, precise, and accurate indexing for full-text documents much faster than users of manual methods. Furthermore, the natural language processing methods that ISAID uses to suggest indexes contributes substantially to increased indexing speed and accuracy.

  14. Methods for Semi-automated Indexing for High Precision Information Retrieval

    PubMed Central

    Berrios, Daniel C.; Cucina, Russell J.; Fagan, Lawrence M.

    2002-01-01

    Objective. To evaluate a new system, ISAID (Internet-based Semi-automated Indexing of Documents), and to generate textbook indexes that are more detailed and more useful to readers. Design. Pilot evaluation: simple, nonrandomized trial comparing ISAID with manual indexing methods. Methods evaluation: randomized, cross-over trial comparing three versions of ISAID and usability survey. Participants. Pilot evaluation: two physicians. Methods evaluation: twelve physicians, each of whom used three different versions of the system for a total of 36 indexing sessions. Measurements. Total index term tuples generated per document per minute (TPM), with and without adjustment for concordance with other subjects; inter-indexer consistency; ratings of the usability of the ISAID indexing system. Results. Compared with manual methods, ISAID decreased indexing times greatly. Using three versions of ISAID, inter-indexer consistency ranged from 15% to 65% with a mean of 41%, 31%, and 40% for each of three documents. Subjects using the full version of ISAID were faster (average TPM: 5.6) and had higher rates of concordant index generation. There were substantial learning effects, despite our use of a training/run-in phase. Subjects using the full version of ISAID were much faster by the third indexing session (average TPM: 9.1). There was a statistically significant increase in three-subject concordant indexing rate using the full version of ISAID during the second indexing session (p < 0.05). Summary. Users of the ISAID indexing system create complex, precise, and accurate indexing for full-text documents much faster than users of manual methods. Furthermore, the natural language processing methods that ISAID uses to suggest indexes contributes substantially to increased indexing speed and accuracy. PMID:12386114

  15. A new method to retrieve spectral absorption coefficient of highly-scattering and weakly-absorbing materials

    NASA Astrophysics Data System (ADS)

    Dombrovsky, Leonid A.

    2016-03-01

    A significant uncertainty in the absorption coefficient of highly scattering dispersed materials is typical in the spectral ranges of very weak absorption. The traditional way to identify the main absorption and scattering characteristics of semi-transparent materials is based on spectral measurements of normal-hemispherical reflectance and transmittance for the material sample. Unfortunately this way cannot be used in the case of in vivo measurements of optical properties of biological tissues. A method suggested in the present paper is based on thermal response to the periodic radiative heating of the open surface of a semi-transparent material. It is shown that the period of a variation of the surface temperature is sensitive to the value of an average absorption coefficient in the surface layer. As a result, the monochromatic external irradiation combined with the surface temperature measurements can be used to retrieve the spectral values of absorption coefficient. Possible application of this method to porous semi-transparent ceramics is considered. An example problem is also solved to illustrate the applicability of this method to human skin. The approach suggested enables one to estimate an average absorption coefficient of human skin of a patient just before the thermal processing.

  16. Method for Face-Emotion Retrieval Using A Cartoon Emotional Expression Approach

    NASA Astrophysics Data System (ADS)

    Kostov, Vlaho; Yanagisawa, Hideyoshi; Johansson, Martin; Fukuda, Shuichi

    A simple method for extracting emotion from a human face, as a form of non-verbal communication, was developed to cope with and optimize mobile communication in a globalized and diversified society. A cartoon face based model was developed and used to evaluate emotional content of real faces. After a pilot survey, basic rules were defined and student subjects were asked to express emotion using the cartoon face. Their face samples were then analyzed using principal component analysis and the Mahalanobis distance method. Feature parameters considered as having relations with emotions were extracted and new cartoon faces (based on these parameters) were generated. The subjects evaluated emotion of these cartoon faces again and we confirmed these parameters were suitable. To confirm how these parameters could be applied to real faces, we asked subjects to express the same emotions which were then captured electronically. Simple image processing techniques were also developed to extract these features from real faces and we then compared them with the cartoon face parameters. It is demonstrated via the cartoon face that we are able to express the emotions from very small amounts of information. As a result, real and cartoon faces correspond to each other. It is also shown that emotion could be extracted from still and dynamic real face images using these cartoon-based features.

  17. Surface soil humidity retrieval using remote sensing techniques: a triangle method validation

    NASA Astrophysics Data System (ADS)

    Maltese, Antonino; Cammalleri, Carmelo; Capodici, Fulvio; Ciraolo, Giuseppe; La Loggia, Goffredo

    2010-10-01

    Soil humidity plays a key-role in hydrological and agricultural processes. In the rainfall-runoff processes the knowledge of its spatial distribution is fundamental to accurately model these phenomena. Furthermore in agronomy and agricultural sciences, assessing the water content of the root zone is required in order to optimize the plant productivity and to improve the irrigation systems management. Despite the importance of this variable the in situ measurements techniques based on Time Domain Reflectometry (TDR) or on the standard thermo-gravimetric methods, are neither cost-effective nor representative of its spatial and temporal variability. Indirect estimations via Earth Observation (EO) images include the triangle method, which shows that Land Surface Temperature (LST) is prevalently controlled by surface and root zone humidity in bare and vegetated soils respectively. The effects of pre-processing techniques correcting for altimetry and seasonality are analyzed by means of shortwave and longwave airborne images acquired on a vineyard during a whole phenological period. The paper also discusses the advantages induced by replacing the absolute temperatures with relative values, that were obtained subtracting the temperatures measured by micrometeorological station or the surface temperature of high thermal inertia surfaces (as small irrigation reservoir) chosen as reference values. The validation with in situ data also highlights that a higher spatial resolution not necessarily imply a higher accuracy.

  18. Methods for Heel Retrieval for Tanks C-101, C-102, and C-111 at the Hanford Site - 13064

    SciTech Connect

    Sams, T.L.; Kirch, N.W.; Reynolds, J.H.

    2013-07-01

    The purpose of this paper is to evaluate the prospects of using bulk waste characteristics to determine the most appropriate heel retrieval technology. If the properties of hard to remove heels can be determined before bulk retrieval, then a heel retrieval technology can be selected before bulk retrieval is complete. This would save substantially on sampling costs and would allow the deployment of the heel retrieval technology immediately after bulk retrieval. The latter would also accelerate the heel removal schedule. A number of C-farm retrievals have been fully or partially completed at the time of this writing. Thus, there is already substantial information on the success of different technologies and the composition of the heels. There is also substantial information on the waste types in each tank based on historical records. Therefore, this study will correlate the performance of technologies used so far and compare them to the known waste types in the tanks. This will be used to estimate the performance of future C Farm heel retrievals. An initial decision tree is developed and employed on tanks C-101, C-102, and C 111. An assumption of this study is that no additional characterization information would be available, before or after retrieval. Note that collecting additional information would substantially increase the probability of success. Deploying some in-situ testing technologies, such as a water lance or an in-situ Raman probe, might substantially increase the probability of successfully selecting the process conditions without having to take samples from the tanks for laboratory analysis. (authors)

  19. Methods for heel retrieval for tanks C-101, C-102, and C-111 at the Hanford Site

    SciTech Connect

    Sams, Terry L.; Kirch, N. W.; Reynolds, Jacob G.

    2013-01-11

    The purpose of this paper is to evaluate the prospects of using bulk waste characteristics to determine the most appropriate heel retrieval technology. If the properties of hard to remove heels can be determined before bulk retrieval, then a heel retrieval technology can be selected before bulk retrieval is complete. This would save substantially on sampling costs and would allow the deployment of the heel retrieval technology immediately after bulk retrieval. The latter would also accelerate the heel removal schedule. A number of C-farm retrievals have been fully or partially completed at the time of this writing. Thus, there is already substantial information on the success of different technologies and the composition of the heels. There is also substantial information on the waste types in each tank based on historical records. Therefore, this study will correlate the performance of technologies used so far and compare them to the known waste types in the tanks. This will be used to estimate the performance of future C Farm heel retrievals. An initial decision tree is developed and employed on tanks C-101, C-102, and C 111. An assumption of this study is that no additional characterization information would be available, before or after retrieval. Note that collecting additional information would substantially increase the probability of success. Deploying some in-situ testing technologies, such as a water lance or an in-situ Raman probe, might substantially increase the probability of successfully selecting the process conditions without having to take samples from the tanks for laboratory analysis.

  20. Gene-Disease Interaction Retrieval from Multiple Sources: A Network Based Method

    PubMed Central

    Huang, Lan; Wang, Yan

    2016-01-01

    The number of gene-related databases has been growing largely along with the research on genes of bioinformatics. Those databases are filled with various gene functions, pathways, interactions, and so forth, while much biomedical knowledge about human diseases is stored as text in all kinds of literatures. Researchers have developed many methods to extract structured biomedical knowledge. Some study and improve text mining algorithms to achieve efficiency in order to cover as many data sources as possible, while some build open source database to accept individual submissions in order to achieve accuracy. This paper combines both efforts and biomedical ontologies to build an interaction network of multiple biomedical ontologies, which guarantees its robustness as well as its wide coverage of biomedical publications. Upon the network, we accomplish an algorithm which discovers paths between concept pairs and shows potential relations. PMID:27478829

  1. Gene-Disease Interaction Retrieval from Multiple Sources: A Network Based Method.

    PubMed

    Huang, Lan; Wang, Ye; Wang, Yan; Bai, Tian

    2016-01-01

    The number of gene-related databases has been growing largely along with the research on genes of bioinformatics. Those databases are filled with various gene functions, pathways, interactions, and so forth, while much biomedical knowledge about human diseases is stored as text in all kinds of literatures. Researchers have developed many methods to extract structured biomedical knowledge. Some study and improve text mining algorithms to achieve efficiency in order to cover as many data sources as possible, while some build open source database to accept individual submissions in order to achieve accuracy. This paper combines both efforts and biomedical ontologies to build an interaction network of multiple biomedical ontologies, which guarantees its robustness as well as its wide coverage of biomedical publications. Upon the network, we accomplish an algorithm which discovers paths between concept pairs and shows potential relations. PMID:27478829

  2. Methods of atomic oxygen and ozone retrieval from observations of the O2 dayglow emissions in the MLT region

    NASA Astrophysics Data System (ADS)

    Yankovsky, Valentine; Martyshenko, Kseniia; Manuilova, Rada

    2015-04-01

    The problem of creating the new methods of remote sensing of altitude profile of the [O(3P)] and [O3] in the daytime is actual for the mesosphere and lower thermosphere range. Currently there is no reliable method for remote sensing of altitude profile of the [O(3P)], but atomic oxygen is a key component in the mechanism of the atmosphere cooling by quenching of vibrationally excited CO2 molecules and also one of basic quencher of excited components in MLT region. The airglow emission in 1.27 µm IR Atm(0 - 0) band from [O2(a1Δg, v=0)] has been used as a proxy for [O3] in MLT for over a decade. However, lifetime of O2(a1Δg, v=0) is more than 1 hour, therefore this method is not suitable for detecting of relatively rapid [O3] variations which occur due to the variability of the solar spectrum in the UV range (120 - 320 nm) and other space factors. The aim of this study is revealing of proxies for retrievals of [O(3P)] and [O3]. In the framework of developed model of electronic vibrational kinetics of excited products of O3 and O2 photolysis in MLT of the Earth (model YM-2011) [1] we consider the photolysis of O2 in the Schumann-Runge continuum and Lyaman-A H atom and of O3 in Hartley band and for excited products of photolysis ( O2(a1Δg, v=0 - 5), O2(b1Σ+g, v=0, 1, 2) and excited oxygen atom O(1D)) we took into account more than 60 aeronomical reactions of photoexcitation and deexcitation by energy transfer between the excited levels and of quenching of the levels in collisions with O(3P) O2, N2, O(3P), O3, CO2. We tested 5 excited components, namely, O2(b1Σ+g, v=0, 1, 2), O2(a1Δg, v=0 - 5) and O(1D) as the O(3P) and O3 proxies. The total system of kinetic equations for 10 components has been solved and altitude profiles of concentrations of O(1D), O2(b1Σ+g, v=0, 1, 2), and O2(a1Δg, v=0 - 5) have been calculated. To compare characteristics of assumed proxies we used sensitivity analysis of the proxy concentrations altitude profiles to variations of [O3] and

  3. A Novel Method to Retrieve Aerosol Optical Thickness from High-Resolution Optical Satellite Images for Air Quality Monitoring

    NASA Astrophysics Data System (ADS)

    Nield, J. M.; Wilson, R. T.; Milton, E. J.

    2015-12-01

    Aerosol Optical Thickness (AOT) data has many important applications including atmospheric correction of satellite imagery and monitoring of particulate matter air pollution. Current data products are generally available at a kilometre-scale resolution, but many applications require far higher resolutions. For example, particulate matter concentrations vary on a metre-scale, and thus data products at a similar scale are required to provide accurate assessments of particle densities and allow effective monitoring of air quality and analysis of local air quality effects on health. A novel method has been developed which retrieves per-pixel AOT values from high-resolution (~30m) satellite data. This method is designed to work over a wide range of land covers - including both bright and dark surfaces - and requires only standard visible and near-infrared data, making it applicable to a range of data from sensors such as Landsat, SPOT and Sentinel-2. The method is based upon an extension of the Haze Optimized Transform (HOT). The HOT was originally designed for assessing areas of thick haze in satellite imagery by calculating a 'haziness' value for each pixel in an image as the distance from a 'Clear Line' in feature space, defined by the high correlation between visible bands. Here, we adapt the HOT method and use it to provide AOT data instead. Significant extensions include Monte Carlo estimation of the 'Clear Line', object-based correction for land cover, and estimation of AOT from the haziness values through radiative transfer modelling. This novel method will enable many new applications of AOT data that were impossible with previously available low-resolution data, and has the potential to contribute significantly to our understanding of the air quality on health, the accuracy of satellite image atmospheric correction and the role of aerosols in the climate system.

  4. Size-exclusion HPLC provides a simple, rapid, and versatile alternative method for quality control of vaccines by characterizing the assembly of antigens.

    PubMed

    Yang, Yanli; Li, Hao; Li, Zhengjun; Zhang, Yan; Zhang, Songping; Chen, Yi; Yu, Mengran; Ma, Guanghui; Su, Zhiguo

    2015-02-25

    The assembly of antigen structure is often crucial to the potency of vaccines. Currently adopted methods like animal testing and ultracentrifugation take long time and are difficult to automate for multiple samples. Here we develop a size-exclusion high-performance liquid chromatography (SE-HPLC) method to characterize the assembly of antigen structure during both manufacturing process and storage. Three important vaccine antigens including inactivated foot and mouth disease virus (FMDV), which is a virus vaccine; and two virus-like particles (VLPs) vaccines involving hepatitis B core antigen (HBcAg) VLPs, and hepatitis B surface antigen (HBsAg) VLPs, were successfully analyzed using commercially available TSK gel columns with pore size above 45nm. Combined with other analytical methods including SDS-PAGE, dynamic light scattering, wavelength scan, and multi-angle laser light scattering, the SE-HPLC method was proven to be a simple, rapid, and reliable tool for antigen particles assembly analysis. Specifically, for FMDV whole virus particle, SE-HPLC was used to analyze 146S content in vaccine preparations and the thermal dissociation of the 146S. For HBcAg-VLPs that are expressed in recombinant Escherichia coli, its expression level during cell culture process was quantitatively monitored by SE-HPLC. The SE-HPLC also showed applicability for quality check of HBsAg vaccine preparations by monitoring the product consistency of different lot number and the product stability during storage. Results shown in this work clearly demonstrated that SE-HPLC method has potential as a versatile alternative technology for control of the final product by both manufacturers and the regulatory agencies.

  5. A Rapid Method to Characterize Mouse IgG Antibodies and Isolate Native Antigen Binding IgG B Cell Hybridomas

    PubMed Central

    Liu, Haolin; White, Janice; Crawford, Frances; Jin, Niyun; Ju, Xiangwu; Liu, Kangtai; Jiang, Chengyu; Marrack, Philippa; Zhang, Gongyi; Kappler, John W.

    2015-01-01

    B cell hybridomas are an important source of monoclonal antibodies. In this paper, we developed a high-throughput method to characterize mouse IgG antibodies using surface plasmon resonance technology. This assay rapidly determines their sub-isotypes, whether they bind native antigen and their approximate affinities for the antigen using only 50 μl of hybridoma cell culture supernatant. Moreover, we found that mouse hybridomas secreting IgG antibodies also have membrane form IgG expression without Igα. Based on this surface IgG, we used flow cytometry to isolate rare γ2a isotype switched variants from a γ2b antibody secreting hybridoma cell line. Also, we used fluorescent antigen to single cell sort antigen binding hybridoma cells from bulk mixture of fused hybridoma cells instead of the traditional multi-microwell plate screening and limiting dilution sub-cloning thus saving time and labor. The IgG monoclonal antibodies specific for the native antigen identified with these methods are suitable for in vivo therapeutic uses, but also for sandwich ELISA assays, histology, flow cytometry, immune precipitation and x-ray crystallography. PMID:26317987

  6. Characterization of anthropogenic methane plumes with the Hyperspectral Thermal Emission Spectrometer (HyTES): a retrieval method and error analysis

    NASA Astrophysics Data System (ADS)

    Kuai, Le; Worden, John R.; Li, King-Fai; Hulley, Glynn C.; Hopkins, Francesca M.; Miller, Charles E.; Hook, Simon J.; Duren, Riley M.; Aubrey, Andrew D.

    2016-07-01

    We introduce a retrieval algorithm to estimate lower tropospheric methane (CH4) concentrations from the surface to 1 km with uncertainty estimates using Hyperspectral Thermal Emission Spectrometer (HyTES) airborne radiance measurements. After resampling, retrievals have a spatial resolution of 6 × 6 m2. The total error from a single retrieval is approximately 20 %, with the uncertainties determined primarily by noise and spectral interferences from air temperature, surface emissivity, and atmospheric water vapor. We demonstrate retrievals for a HyTES flight line over storage tanks near Kern River Oil Field (KROF), Kern County, California, and find an extended plume structure in the set of observations with elevated methane concentrations (3.0 ± 0.6 to 6.0 ± 1.2 ppm), well above mean concentrations (1.8 ± 0.4 ppm) observed for this scene. With typically a 20 % estimated uncertainty, plume enhancements with more than 1 ppm are distinguishable from the background values with its uncertainty. HyTES retrievals are consistent with simultaneous airborne and ground-based in situ CH4 mole fraction measurements within the reported accuracy of approximately 0.2 ppm (or ˜ 8 %), due to retrieval interferences related to air temperature, emissivity, and H2O.

  7. A new method for fusion, denoising and enhancement of x-ray images retrieved from Talbot-Lau grating interferometry

    NASA Astrophysics Data System (ADS)

    Scholkmann, Felix; Revol, Vincent; Kaufmann, Rolf; Baronowski, Heidrun; Kottler, Christian

    2014-03-01

    This paper introduces a new image denoising, fusion and enhancement framework for combining and optimal visualization of x-ray attenuation contrast (AC), differential phase contrast (DPC) and dark-field contrast (DFC) images retrieved from x-ray Talbot-Lau grating interferometry. The new image fusion framework comprises three steps: (i) denoising each input image (AC, DPC and DFC) through adaptive Wiener filtering, (ii) performing a two-step image fusion process based on the shift-invariant wavelet transform, i.e. first fusing the AC with the DPC image and then fusing the resulting image with the DFC image, and finally (iii) enhancing the fused image to obtain a final image using adaptive histogram equalization, adaptive sharpening and contrast optimization. Application examples are presented for two biological objects (a human tooth and a cherry) and the proposed method is compared to two recently published AC/DPC/DFC image processing techniques. In conclusion, the new framework for the processing of AC, DPC and DFC allows the most relevant features of all three images to be combined in one image while reducing the noise and enhancing adaptively the relevant image features. The newly developed framework may be used in technical and medical applications.

  8. Retrieval of GOMOS bright limb ozone profiles

    NASA Astrophysics Data System (ADS)

    Tukiainen, Simo; Verronen, Pekka T.; Kyrola, Erkki; Tamminen, Johanna

    GOMOS is a stellar occultation instrument on board the ENVISAT satellite. During day time occultations limb scattered sunlight spectra are also recorded. These can be used to retrieve vertical profiles of ozone between 15-70 km. The retrieval method is the modified onion peeling inversion method that we have used earlier for retrievals from the OSIRIS instrument. In the retrieval we use an accurate single scattering modeling and look up tables for the multiple scattering modeling. The look up tables are produced using the Monte Carlo radiative transfer model Siro. We present here examples of the retrievals and compare our results with GOMOS occultation retrievals and OSIRIS retrievals.

  9. [Improvement of sensitivity in the second generation HCV core antigen assay by a novel concentration method using polyethylene glycol (PEG)].

    PubMed

    Higashimoto, Makiko; Takahashi, Masahiko; Jokyu, Ritsuko; Syundou, Hiromi; Saito, Hidetsugu

    2007-11-01

    A HCV core antigen (Ag) detection assay system, Lumipulse Ortho HCV Ag has been developed and is commercially available in Japan with a lower detection level limit of 50 fmol/l, which is equivalent to 20 KIU/ml in PCR quantitative assay. HCV core Ag assay has an advantage of broader dynamic range compared with PCR assay, however the sensitivity is lower than PCR. We developed a novel HCV core Ag concentration method using polyethylene glycol (PEG), which can improve the sensitivity five times better than the original assay. The reproducibility was examined by consecutive five-time measurement of HCV patients serum, in which the results of HCV core Ag original and concentrated method were 56.8 +/- 8.1 fmol/l (mean +/- SD), CV 14.2% and 322.9 +/- 45.5 fmol/l CV 14.0%, respectively. The assay results of HCV negative samples in original HCV core Ag were all 0.1 fmol/l and the results were same even in the concentration method. The results of concentration method were 5.7 times higher than original assay, which was almost equal to theoretical rate as expected. The assay results of serially diluted samples were also as same as expected data in both original and concentration assay. We confirmed that the sensitivity of HCV core Ag concentration method had almost as same sensitivity as PCR high range assay in the competitive assay study using the serially monitored samples of five HCV patients during interferon therapy. A novel concentration method using PEG in HCV core Ag assay system seems to be useful for assessing and monitoring interferon treatment for HCV.

  10. Epstein-Barr virus early antigen titer by immunofluorescence in microplates. A new semi-automated method based on microtiter system.

    PubMed

    Favart, A M; Lamy, M E; Allemeersch, D; Burtonboy, G; Vanoverschelde, J

    1978-11-17

    For the titration of antibodies directed against Epstein-Barr Virus early antigen (EBV-EA) we describe a method in microplates with the Microtiter System (Cooke Engineering Co., Alexandria, Va). Using this technique, which allows rapid epidemiological investigations, we have titered anti-EBV-EA antibodies in different groups of patients and controls, and particularly in group which had recent contact with infectious mononucleosis. In this group the percentage of individuals having antibodies directed against the EBV-EA antigen was significantly higher than in the group of controls.

  11. A Solar Reflectance Method for Retrieving Cloud Optical Thickness and Droplet Size Over Snow and Ice Surfaces

    NASA Technical Reports Server (NTRS)

    Platnick, S.; Li, J. Y.; King, M. D.; Gerber, H.; Hobbs, P. V.

    1999-01-01

    Cloud optical thickness and effective radius retrievals from solar reflectance measurements are traditionally implemented using a combination of spectral channels that are absorbing and non-absorbing for water particles. Reflectances in non-absorbing channels (e.g., 0.67, 0.86, 1.2 micron spectral window bands) are largely dependent on cloud optical thickness, while longer wavelength absorbing channels (1.6, 2. 1, and 3.7 micron window bands) provide cloud particle size information. Cloud retrievals over ice and snow surfaces present serious difficulties. At the shorter wavelengths, ice is bright and highly variable, both characteristics acting to significantly increase cloud retrieval uncertainty. In contrast, reflectances at the longer wavelengths are relatively small and may be comparable to that of dark open water. A modification to the traditional cloud retrieval technique is devised. The new algorithm uses only a combination of absorbing spectral channels for which the snow/ice albedo is relatively small. Using this approach, retrievals have been made with the MODIS Airborne Simulator (MAS) imager flown aboard the NASA ER-2 from May - June 1998 during the Arctic FIRE-ACE field deployment. Data from several coordinated ER-2 and University of Washington CV-580 in situ aircraft observations of liquid water stratus clouds are examined. MAS retrievals of optical thickness, droplet effective radius, and liquid water path are shown to be in good agreement with the in situ measurements. The initial success of the technique has implications for future operational satellite cloud retrieval algorithms in polar and wintertime regions.

  12. A microarray method for identifying tumor antigens by screening a tumor cDNA expression library against cancer sera

    PubMed Central

    Whittemore, Kurt; Sykes, Kathryn

    2013-01-01

    The immune system responds to tumor cells. The challenge has been how to effectively use these responses to treat or protect against cancer. Toward the goal of developing a cancer vaccine, we are pursuing methodologies for the discovery and testing of useful antigens. We present an array-based approach for discovering these B cell antigens by directly screening for specific host-sera reactivity to lysates from tumor-derived cDNA expression libraries. Several cancer-specific antigens were identified, and these are currently being validated as potential candidates. PMID:23851590

  13. [Accelerated method of detecting antibodies to tick-borne encephalitis and Isfahan viruses on fixed smears of antigen-containing cells].

    PubMed

    Sveshnikova, N A; Gaĭdamovich, S Ia

    1980-01-01

    A modification is suggested of the indirect method of fluorescent antibodies (IMFA) for rapid diagnosis of the TBE and Isfagan viruses in fixed smears of antigen-containing cells. Preparation of such smears with equal numbers of antigen-containing cells in a monolayer covering the whole area of the depression inoculated with the infected cellular suspension ensures standard conditions for the test and comparable results. The titer of the sera in the smears determined with the IMFA is higher or similar to that obtained in the infected monolayer cultures grown on slides. One preparation can be used not only for the serum antibody identification but also for its titration. It takes no more than 4-5 hours to analyse the test sera. The fixed preparation with the antigen-containing cells can be stored during 6 months at -20 degrees C with no specificity lost. Availability of such preparations in stock will permit the IMFA to be applied in rapid diagnosis.

  14. A differential optical absorption spectroscopy method for retrieval from ground-based Fourier transform spectrometers measurements of the direct solar beam

    NASA Astrophysics Data System (ADS)

    Huo, Yanfeng; Duan, Minzheng; Tian, Wenshou; Min, Qilong

    2015-08-01

    A differential optical absorption spectroscopy (DOAS)-like algorithm is developed to retrieve the column-averaged dryair mole fraction of carbon dioxide from ground-based hyper-spectral measurements of the direct solar beam. Different to the spectral fitting method, which minimizes the difference between the observed and simulated spectra, the ratios of multiple channel-pairs—one weak and one strong absorption channel—are used to retrieve from measurements of the shortwave infrared (SWIR) band. Based on sensitivity tests, a super channel-pair is carefully selected to reduce the effects of solar lines, water vapor, air temperature, pressure, instrument noise, and frequency shift on retrieval errors. The new algorithm reduces computational cost and the retrievals are less sensitive to temperature and H2O uncertainty than the spectral fitting method. Multi-day Total Carbon Column Observing Network (TCCON) measurements under clear-sky conditions at two sites (Tsukuba and Bremen) are used to derive xxxx for the algorithm evaluation and validation. The DOAS-like results agree very well with those of the TCCON algorithm after correction of an airmass-dependent bias.

  15. Analysis of thickness fields retrieved from NOAA-7 observations through the 3I (Improved Initialization Inversion) method. Interest for weather forecasting

    NASA Astrophysics Data System (ADS)

    Chedin, A.; Scott, N. A.; Flobert, J.; Husson, N.; Levy, C.; Rochard, G.; Quere, J.; Bellec, B.; Simeon, J.

    1987-08-01

    The improved initialization inversion method for the 3 dimensional analysis of the atmospheric structure from satellite obsevations (TIROS-N series) was applied to NOAA-7 data over Europe. The scenes selected correspond to complex meteorological situations and resulted in substantial errors in forecasting. One of the situations is presented. Comparisons between retrieved and operational (conventional) thickness charts show that the method is ready for operational use.

  16. Retrievability Strategy Report

    SciTech Connect

    Gehner, P; Gilstrap, O J; Memory, R D; Wagner, R C

    1997-04-30

    Section 122 of the ''Nuclear Waste Policy Act'' requires that a repository be designed and constructed to permit retrieval of any spent fuel placed in such repository, during an appropriate period of operation of the facility, for one of these reasons: (1) to protect public health and safety, or the environment; and (2) to permit the recovery of the economically valuable contents of such spent fuel. The Act also requires the Secretary to specify an appropriate period of retrievability at the time of the design of a repository. The Secretary has not yet defined any such period. However, the Nuclear Regulatory Commission, in the Code of Federal Regulations Title 10 Part 60.111, requires the design of a geologic repository operations area to allow the retrieval of any or all waste on a reasonable schedule starting at any time up to 50 years after waste operations are initiated. NRC describes a reasonable schedule as one that would permit retrieval in about the same time as it took to construct the repository and emplace the waste. Based on the existing conceptual repository and waste package design and analysis, the Yucca Mountain Project described retrieval operations under normal and abnormal conditions in the 1988 ''Site Characterization Plan (SCP)'' document. In 1991, under the same design assumptions, the Project issued a ''Retrieval Strategy Report for a Potential High-Level Nuclear Waste Repository''. Both the conceptual design of the waste package and the emplacement methods have since changed significantly. This report presents the results of a study to determine whether and to what degree these design and other changes require a revision of the retrieval strategy and, if they do, to recommend a revised strategy. The aim of such a revised strategy was to inform decision makers on how to proceed with design to allow retrievability.

  17. Principles and methods of immunohistochemistry.

    PubMed

    Ramos-Vara, José A

    2011-01-01

    Immunohistochemical techniques detect antigens in tissue sections by means of immunological and chemical reactions. This technique is highly sensitive and specific and can detect a wide variety of antigens in multiple animal species. This chapter reviews common immunohistochemical methods used in the characterization of normal and pathologic tissue and the reagents used. Pretreatments such as blocking steps for endogenous activities and antigen retrieval are included. Standard procedures on formalin-fixed, paraffin-embedded tissues as well as method standardization for new antibodies and troubleshooting are emphasized.

  18. A method to identify protein antigens of Dermanyssus gallinae for the protection of birds from poultry mites.

    PubMed

    Makert, Gustavo R; Vorbrüggen, Susanne; Krautwald-Junghanns, Maria-Elisabeth; Voss, Matthias; Sohn, Kai; Buschmann, Tilo; Ulbert, Sebastian

    2016-07-01

    The poultry red mite (PRM) Dermanyssus gallinae causes high economic losses and is among the most important parasites in poultry farming worldwide. Different chemical, physical, and biological strategies try to control the expansion of PRM. However, effective solutions to this problem still have to be found. Here, we present a method for the development of an immunological control strategy, based on the identification of mite protein antigens which elicit antibodies with anti-mite activity in the immunized chicken. Hens were immunized with different PRM protein extracts formulated with two different adjuvants, and IgY-antibodies were isolated from the eggs. A PRM in vitro feeding assay which used chicken blood spiked with these IgY-preparations was used to detect antibodies which caused PRM mortality. In vitro feeding of mites with IgY isolated from hens immunized with PRM extract formulated with one of the adjuvants showed a statistically significant increase in the mortality as compared to control mites. After the separation of total PRM extracts in two-dimensional gels, several protein spots were recognized by such IgY preparations. Ten protein spots were subjected to mass spectrometry (MS/MS) for the identification of the corresponding proteins. Complete protein sequences were deduced from genomic and transcriptomic assemblies derived from high throughput sequencing of total PRM DNA and RNA. The results may contribute to the development of an immunological control strategy of D. gallinae. PMID:27026505

  19. A method to identify protein antigens of Dermanyssus gallinae for the protection of birds from poultry mites.

    PubMed

    Makert, Gustavo R; Vorbrüggen, Susanne; Krautwald-Junghanns, Maria-Elisabeth; Voss, Matthias; Sohn, Kai; Buschmann, Tilo; Ulbert, Sebastian

    2016-07-01

    The poultry red mite (PRM) Dermanyssus gallinae causes high economic losses and is among the most important parasites in poultry farming worldwide. Different chemical, physical, and biological strategies try to control the expansion of PRM. However, effective solutions to this problem still have to be found. Here, we present a method for the development of an immunological control strategy, based on the identification of mite protein antigens which elicit antibodies with anti-mite activity in the immunized chicken. Hens were immunized with different PRM protein extracts formulated with two different adjuvants, and IgY-antibodies were isolated from the eggs. A PRM in vitro feeding assay which used chicken blood spiked with these IgY-preparations was used to detect antibodies which caused PRM mortality. In vitro feeding of mites with IgY isolated from hens immunized with PRM extract formulated with one of the adjuvants showed a statistically significant increase in the mortality as compared to control mites. After the separation of total PRM extracts in two-dimensional gels, several protein spots were recognized by such IgY preparations. Ten protein spots were subjected to mass spectrometry (MS/MS) for the identification of the corresponding proteins. Complete protein sequences were deduced from genomic and transcriptomic assemblies derived from high throughput sequencing of total PRM DNA and RNA. The results may contribute to the development of an immunological control strategy of D. gallinae.

  20. Guenter Tulip Filter Retrieval Experience: Predictors of Successful Retrieval

    SciTech Connect

    Turba, Ulku Cenk Arslan, Bulent Meuse, Michael Sabri, Saher; Macik, Barbara Gail

    2010-08-15

    We report our experience with Guenter Tulip filter placement indications, retrievals, and procedural problems, with emphasis on alternative retrieval techniques. We have identified 92 consecutive patients in whom a Guenter Tulip filter was placed and filter removal attempted. We recorded patient demographic information, filter placement and retrieval indications, procedures, standard and nonstandard filter retrieval techniques, complications, and clinical outcomes. The mean time to retrieval for those who experienced filter strut penetration was statistically significant [F(1,90) = 8.55, p = 0.004]. Filter strut(s) IVC penetration and successful retrieval were found to be statistically significant (p = 0.043). The filter hook-IVC relationship correlated with successful retrieval. A modified guidewire loop technique was applied in 8 of 10 cases where the hook appeared to penetrate the IVC wall and could not be engaged with a loop snare catheter, providing additional technical success in 6 of 8 (75%). Therefore, the total filter retrieval success increased from 88 to 95%. In conclusion, the Guenter Tulip filter has high successful retrieval rates with low rates of complication. Additional maneuvers such as a guidewire loop method can be used to improve retrieval success rates when the filter hook is endothelialized.

  1. Retrieval with gene queries

    PubMed Central

    Sehgal, Aditya K; Srinivasan, Padmini

    2006-01-01

    Background Accuracy of document retrieval from MEDLINE for gene queries is crucially important for many applications in bioinformatics. We explore five information retrieval-based methods to rank documents retrieved by PubMed gene queries for the human genome. The aim is to rank relevant documents higher in the retrieved list. We address the special challenges faced due to ambiguity in gene nomenclature: gene terms that refer to multiple genes, gene terms that are also English words, and gene terms that have other biological meanings. Results Our two baseline ranking strategies are quite similar in performance. Two of our three LocusLink-based strategies offer significant improvements. These methods work very well even when there is ambiguity in the gene terms. Our best ranking strategy offers significant improvements on three different kinds of ambiguities over our two baseline strategies (improvements range from 15.9% to 17.7% and 11.7% to 13.3% depending on the baseline). For most genes the best ranking query is one that is built from the LocusLink (now Entrez Gene) summary and product information along with the gene names and aliases. For others, the gene names and aliases suffice. We also present an approach that successfully predicts, for a given gene, which of these two ranking queries is more appropriate. Conclusion We explore the effect of different post-retrieval strategies on the ranking of documents returned by PubMed for human gene queries. We have successfully applied some of these strategies to improve the ranking of relevant documents in the retrieved sets. This holds true even when various kinds of ambiguity are encountered. We feel that it would be very useful to apply strategies like ours on PubMed search results as these are not ordered by relevance in any way. This is especially so for queries that retrieve a large number of documents. PMID:16630348

  2. Multiple-scattering lidar retrieval method: tests on Monte Carlo simulations and comparisons with in situ measurements.

    PubMed

    Bissonnette, Luc R; Roy, Gilles; Poutier, Laurent; Cober, Stewart G; Isaac, George A

    2002-10-20

    A multiple-field-of-view (MFOV) lidar measurement and solution technique has been developed to exploit the retrievable particle extinction and size information contained in the multiple-scattering contributions to aerosol lidar returns. We describe the proposed solution algorithm. The primary retrieved parameters are the extinction coefficient at the lidar wavelength and the effective particle diameter from which secondary products such as the extinction at other wavelengths and the liquid-water content (LWC) of liquid-phase clouds can be derived. The solutions are compared with true values in a series of Monte Carlo simulations and with in-cloud measurements. Good agreement is obtained for the simulations. For the field experiment, the retrieved effective droplet diameter and LWC for the available seven cases studied are on average 15% and 35% (worst case) smaller than the measured data, respectively. In the latter case, the analysis shows that the differences cannot be attributed solely to lidar inversion errors. Despite the limited penetration depth (150-300 m) of the lidar pulses, the results of the studied cases indicate that the retrieved lidar solutions remain statistically representative of measurements performed over the full cloud extent. Long-term MFOV lidar monitoring could thus become a practical and economical option for cloud statistical studies but more experimentation on more varied cloud conditions, especially for LWC, is still needed.

  3. Rapid and Accurate Determination of Lipopolysaccharide O-Antigen Types in Klebsiella pneumoniae with a Novel PCR-Based O-Genotyping Method

    PubMed Central

    Shih, Yun-Jui; Cheong, Cheng-Man; Yi, Wen-Ching

    2015-01-01

    Klebsiella pneumoniae, a Gram-negative bacillus that causes life-threatening infections in both hospitalized patients and ambulatory persons, can be classified into nine lipopolysaccharide (LPS) O-antigen serotypes. The O-antigen type has important clinical and epidemiological significance. However, K. pneumoniae O serotyping is cumbersome, and the reagents are not commercially available. To overcome the limitations of conventional serotyping methods, we aimed to create a rapid and accurate PCR method for K. pneumoniae O genotyping. We sequenced the genetic determinants of LPS O antigen from serotypes O1, O2a, O2ac, O3, O4, O5, O8, O9, and O12. We established a two-step genotyping scheme, based on the two genomic regions associated with O-antigen biosynthesis. The first set of PCR primers, which detects alleles at the wzm-wzt loci of the wb gene cluster, distinguishes between O1/O2, O3, O4, O5, O8, O9, and O12. The second set of PCR primers, which detects alleles at the wbbY region, further differentiates between O1, O2a, and O2ac. We verified the specificity of O genotyping against the O-serotype reference strains. We then tested the sensitivity and specificity of O genotyping in K. pneumoniae, using the 56 K-serotype reference strains with known O serotypes determined by an inhibition enzyme-linked immunosorbent assay (iELISA). There is a very good correlation between the O genotypes and classical O serotypes. Three discrepancies were observed and resolved by nucleotide sequencing—all in favor of O genotyping. The PCR-based O genotyping, which can be easily performed in clinical and research microbiology laboratories, is a rapid and accurate method for determining the LPS O-antigen types of K. pneumoniae isolates. PMID:26719438

  4. The development of a shield machine requiring no reception shaft: A pipejacking method enabling shield withdrawl and retrieval at the starting shaft

    SciTech Connect

    Uno, Hideki; Takemoto, A.

    1996-08-01

    This paper describes a pipe-roof construction method, known as an auxiliary method to temporarily prevent ground from collapsing during underground construction. A shield machine developed for this technique, problems encountered, and experimental and project records are also detailed. The pipe-roof construction method uses a pipejacking method performed by a tunnelling machine. Thrust data analysis, experiments on the inside diameter of steel pipes, and experiments on the cutting of shear pin were performed to determine the inside diameter of the steel pipes in order to develop a retrievable shield machine. The results of the construction project indicated areas for further development. 13 figs., 3 tabs.

  5. A fast method for the retrieval of integrated longwave and shortwave top-of-atmosphere upwelling irradiances from MSG/SEVIRI (RRUMS)

    NASA Astrophysics Data System (ADS)

    Vázquez-Navarro, M.; Mayer, B.; Mannstein, H.

    2013-10-01

    A new Rapid Retrieval of Upwelling irradiances from MSG/SEVIRI (RRUMS) is presented. It has been developed to observe the top-of-atmosphere irradiances of small scale and rapidly changing features that are not sufficiently resolved by specific Earth radiation budget sensors. Our retrieval takes advantage of the spatial and temporal resolution of MSG/SEVIRI and provides outgoing longwave and reflected shortwave radiation only by means of a combination of SEVIRI channels. The longwave retrieval is based on a simple linear combination of brightness temperatures from the SEVIRI infrared channels. The shortwave retrieval is based on a neural network that requires as input the visible and near-infrared SEVIRI channels. Both LW and SW algorithms have been validated by comparing their results with CERES and GERB irradiance observations. While being less accurate than their dedicated counterparts, the SEVIRI-based methods have two major advantages compared to CERES and GERB: their higher spatial resolution and the better temporal resolution. With our retrievals it is possible to observe the radiative effect of small-scale features such as cumulus clouds, cirrus clouds, or aircraft contrails. The spatial resolution of SEVIRI is 3 km × 3 km in the sub-satellite point, remarkably better than that of CERES (20 km) or GERB (45 km). The temporal resolution is 15 min (5 min in the Rapid-Scan mode), the same as GERB, but significantly better than that of CERES which, being on board of a polar orbiting satellite, has a temporal resolution as low as 2 overpasses per day.

  6. Plaque/focus immunoassay: a simple method for detecting antiviral monoclonal or other antibodies and viral antigens in cells.

    PubMed

    Pauli, G; Gregersen, J P; Ludwig, H

    1984-11-30

    A new, simple enzyme-linked immunosorbent assay (ELISA) is described which is performed directly on infected and fixed cell cultures in microtitre plates. It permits large scale screening of antiviral monoclonal antibodies and differentiation of specific antibodies from those usually responsible for high background reactions in other ELISA techniques. Time consuming purification of antigens is thus avoided. The plaque/focus immunoassay is also applicable to titration of antibodies in patients' sera and antigens in lytically or non-lytically virus-infected cells. It may also be used to localize antigens in different cell compartments. This immunoassay requires no special equipment and results may be evaluated either with the naked eye or using a light microscope.

  7. Retrieval of atmospheric temperature and moisture vertical profiles from satellite Advanced Infrared Sounder radiances with a new regularization parameter selecting method

    NASA Astrophysics Data System (ADS)

    Zhang, Kun; Wu, Chunqiang; Li, Jun

    2016-06-01

    Considering the characteristics of nonlinear problems, a new method based on the L-curve method and including the concept of entropy was designed to select the regularization parameter in the one-dimensional variational analysis-based sounding retrieval method. In the first iteration, this method uses an empirical regularization parameter derived by minimizing the entropy of variables. During subsequent iterations, it uses the L-curve method to select the regularization parameter in the vicinity of the regularization parameter selected in the last iteration. The new method was employed to select the regularization parameter in retrieving atmospheric temperature and moisture profiles from Atmospheric Infrared Sounder radiance measurements selected from the first day of each month in 2008. The results show that compared with the original L-curve method, the new method yields 5.5% and 2.5% improvements on temperature and relative humidity profiles, respectively. Compared with the discrepancy principle method, the improvements on temperature and relative humidity profiles are 1.6% and 2.0%, respectively.

  8. Snow depth and snow cover retrieval from FengYun3B microwave radiation imagery based on a snow passive microwave unmixing method in Northeast China

    NASA Astrophysics Data System (ADS)

    Gu, Lingjia; Ren, Ruizhi; Zhao, Kai; Li, Xiaofeng

    2014-01-01

    The precision of snow parameter retrieval is unsatisfactory for current practical demands. The primary reason is because of the problem of mixed pixels that are caused by low spatial resolution of satellite passive microwave data. A snow passive microwave unmixing method is proposed in this paper, based on land cover type data and the antenna gain function of passive microwaves. The land cover type of Northeast China is partitioned into grass, farmland, bare soil, forest, and water body types. The component brightness temperatures (CBT), namely unmixed data, with 1 km data resolution are obtained using the proposed unmixing method. The snow depth determined by the CBT and three snow depth retrieval algorithms are validated through field measurements taken in forest and farmland areas of Northeast China in January 2012 and 2013. The results show that the overall of the retrieval precision of the snow depth is improved by 17% in farmland areas and 10% in forest areas when using the CBT in comparison with the mixed pixels. The snow cover results based on the CBT are compared with existing MODIS snow cover products. The results demonstrate that more snow cover information can be obtained with up to 86% accuracy.

  9. A high-throughput optomechanical retrieval method for sequence-verified clonal DNA from the NGS platform.

    PubMed

    Lee, Howon; Kim, Hyoki; Kim, Sungsik; Ryu, Taehoon; Kim, Hwangbeom; Bang, Duhee; Kwon, Sunghoon

    2015-01-01

    Writing DNA plays a significant role in the fields of synthetic biology, functional genomics and bioengineering. DNA clones on next-generation sequencing (NGS) platforms have the potential to be a rich and cost-effective source of sequence-verified DNAs as a precursor for DNA writing. However, it is still very challenging to retrieve target clonal DNA from high-density NGS platforms. Here we propose an enabling technology called 'Sniper Cloning' that enables the precise mapping of target clone features on NGS platforms and non-contact rapid retrieval of targets for the full utilization of DNA clones. By merging the three cutting-edge technologies of NGS, DNA microarray and our pulse laser retrieval system, Sniper Cloning is a week-long process that produces 5,188 error-free synthetic DNAs in a single run of NGS with a single microarray DNA pool. We believe that this technology has potential as a universal tool for DNA writing in biological sciences. PMID:25641679

  10. A high-throughput optomechanical retrieval method for sequence-verified clonal DNA from the NGS platform.

    PubMed

    Lee, Howon; Kim, Hyoki; Kim, Sungsik; Ryu, Taehoon; Kim, Hwangbeom; Bang, Duhee; Kwon, Sunghoon

    2015-02-02

    Writing DNA plays a significant role in the fields of synthetic biology, functional genomics and bioengineering. DNA clones on next-generation sequencing (NGS) platforms have the potential to be a rich and cost-effective source of sequence-verified DNAs as a precursor for DNA writing. However, it is still very challenging to retrieve target clonal DNA from high-density NGS platforms. Here we propose an enabling technology called 'Sniper Cloning' that enables the precise mapping of target clone features on NGS platforms and non-contact rapid retrieval of targets for the full utilization of DNA clones. By merging the three cutting-edge technologies of NGS, DNA microarray and our pulse laser retrieval system, Sniper Cloning is a week-long process that produces 5,188 error-free synthetic DNAs in a single run of NGS with a single microarray DNA pool. We believe that this technology has potential as a universal tool for DNA writing in biological sciences.

  11. Label-free and real-time detection of antigen-antibody interactions by Oblique-incidence Reflectivity Difference (OIRD) method

    NASA Astrophysics Data System (ADS)

    He, LiPing; Sun, Yue; Dai, Jun; Wang, JingYi; Lü, HuiBin; Wang, ShuFang; Jin, KuiJuan; Zhou, YueLiang; Yang, GuoZhen

    2012-09-01

    We label-free and real-time detected three interaction processes of antigen-antibodies, Human Immunoglobulin G (IgG), Rabbit IgG, and Mouse IgG as the targets, and Goat Anti-human IgG, Goat Anti-rabbit IgG, and Goat Anti-mouse IgG as the probe, by the Oblique-incidence Reflectivity Difference (OIRD) method. The interaction dynamic curves of the OIRD signal, corresponding to the interaction processes of antigen-antibodies, are generated. The reaction times from beginning to equilibrium state are about 1800, 900, and 1200 s for Human IgG, Rabbit IgG, and Mouse IgG, respectively. The experimental results demonstrate that the OIRD method not only can distinguish biomolecular interactions, but also can be used in real-time detection of interactions and dynamic processes of biomolecules.

  12. Single Shell Tank (SST) Retrieval Sequence FY 2000 Update

    SciTech Connect

    GARFIELD, J.S.

    2000-09-27

    This document describes the baseline single-shell tank (SST) waste retrieval sequence for the River Protection Project (RPP) updated for Fiscal Year 2000. The SST retrieval sequence identifies the proposed retrieval order (sequence), the tank selection and prioritization rationale, and planned retrieval dates for Hanford SSTs. In addition, the tank selection criteria and reference retrieval method for this sequence are discussed.

  13. Natural Language Information Retrieval: Progress Report.

    ERIC Educational Resources Information Center

    Perez-Carballo, Jose; Strzalkowski, Tomek

    2000-01-01

    Reports on the progress of the natural language information retrieval project, a joint effort led by GE (General Electric) Research, and its evaluation at the sixth TREC (Text Retrieval Conference). Discusses stream-based information retrieval, which uses alternative methods of document indexing; advanced linguistic streams; weighting; and query…

  14. Methods for the in vitro determination of an individual disposition towards TH1- or TH2-reactivity by the application of appropriate stimulatory antigens

    PubMed Central

    BARTH, H; BERG, P A; KLEIN, R

    2003-01-01

    In this study we performed several methods for the determination of cytokines (RT-PCR for the demonstration of cytokine mRNA and flow cytometry for the analysis of intracellular cytokines) and compared them with a recently established test system stimulating peripheral blood mononuclear cells (PBMC) with TH1- and TH2-relevant recall antigens and analysing type 1 and type 2 cytokines by ELISA. Aim of the study was therefore to evaluate the reliability of TH1/TH2 cytokine profiles in two individuals with different types of an allergic/atopic disposition: one of them showed a strong TH1/type 1-mediated tuberculin-reaction (subject A), the other (subject B) revealed elevated IgE-levels and eosinophil counts (TH2/type 2-mediated). PBMC were incubated with the type 1-antigen purified protein derivative (PPD) and the type 2-antigen tetanus-toxoid (TT) for seven days. From the comparison of ELISA with RT-PCR and flow cytometry-analysis it became evident that all three methods allowed the definition of subject A as a ‘type 1-responder’. Subject B showed a pure type 2-response in the ELISA method; PCR and flow cytometry analysis revealed the simultaneous production of type 1- and type 2-cytokines resulting in a mixed type 1/type 2-profile. Active immunization of subject A with TT at the end of the observation period of 12 months resulted in a transient shift from type 1- to a mixed type 1/type 2-profile (simultaneous PPD-induced IFN-γ- and TT-induced IL-5 production). From this pilot study based on clear cut clinical criteria concerning either a humoral or cellular immunological reactivity towards allergens/antigens it is suggested that the determination of type 1/type 2-cytokines by ELISA in supernatants of PBMC stimulated with type 1/type 2-relevant antigens is a useful approach for a better classification of ‘type1-’ or ‘type 2-responder’. PMID:12974758

  15. Retrieval of specimens in laparoscopy using reclosable zipper-type plastic bags: a simple, cheap, and useful method.

    PubMed

    Weber, A; Vázquez, J A; Valencia, S; Cueto, J

    1998-12-01

    Surgical specimens must often be extracted during laparoscopic surgery. Although the technologic advances in this field are amazing, simple measures may sometimes work even better than very sophisticated instruments. This is true of the reclosable plastic bags with zipper-type closure that we use for retrieving surgical specimens from the abdominal cavity in order to protect it as well as the abdominal wall. The bags are cheap, offer no problems for sterilization, are easy to obtain, and are available in many sizes. They are very simple to handle, making it easy to slip in the specimen and then extract it from the abdominal cavity. We describe our experience with these bags and a technique for manipulating them.

  16. A system for storage of references. A method of storage and retrieval of references on a personal microcomputer.

    PubMed

    Alagesan, K; McLeod, G F

    1985-11-01

    A computer program, written in BBC BASIC, for storage and retrieval of literature references on a personal microcomputer fitted with floppy disc drives is described. The storage capacity is 425 references per 100K disc. A versatile search function allows ready access to references by matching any number of combinations of the following 10 items: authors, name, year and volume of journal, pages, reference number, and up to four key words. The resulting bibliographic list can be formatted to any desired house style. There is a facility for sorting the list into alphabetical order of the authors and the use of a wordprocessor for special print styles on any BBC compatible printer. These two features make retyping the list unnecessary. A search can be done manually, while browsing through the references. Advantages of this system over the existing packages are discussed. The program is totally run by on-screen menus, and it is easy to use, even by a novice. PMID:3907401

  17. Tangent height registration method for the Version 1.4 data retrieval algorithm of the solar occultation sensor ILAS-II.

    PubMed

    Tanaka, Tomoaki; Nakajima, Hideaki; Sugita, Takafumi; Ejiri, Mitsumu K; Irie, Hitoshi; Saitoh, Naoko; Terao, Yukio; Kawasaki, Hiroyuki; Usami, Masatoshi; Yokota, Tatsuya; Kobayashi, Hirokazu; Sasano, Yasuhiro

    2007-10-10

    The Improved Limb Atmospheric Spectrometer-II (ILAS-II) is a satellite-borne solar occultation sensor onboard the Advanced Earth Observing Satellite-II (ADEOS-II). The ILAS-II succeeded the ILAS. The ILAS-II used four grating spectrometers to observe vertical profiles of gas volume mixing ratios of trace constituents and was also equipped with a Sun-edge sensor to determine tangent heights geometrically with high precision. The accuracy of gas volume mixing ratios depends on the accuracy of the tangent height determination. The combination method is a tangent height registration method that was developed to give appropriate tangent heights for the ILAS-II Version 1.4 data retrieval algorithm. This study describes the method used in the ILAS-II Version 1.4 retrieval algorithm to register tangent heights. The root-sum-square total random error is estimated to be 30 m, and the total systematic error is 180 m at an altitude of 30 km. The influence of the tangent height errors on the vertical profiles of gas volume mixing ratios in ILAS-II Version 1.4 is estimated by using the relative difference. The relative difference for each species is within 7% (20%) for an altitude shift of +/-100 m(+/-300 m).

  18. Evaluating the Utility of Satellite Soil Moisture Retrievals over Irrigated Areas and the Ability of Land Data Assimilation Methods to Correct for Unmodeled Processes

    NASA Technical Reports Server (NTRS)

    Kumar, S. V.; Peters-Lidard, C. D.; Santanello, J. A.; Reichle, R. H.; Draper, C. S.; Koster, R. D.; Nearing, G.; Jasinski, M. F.

    2015-01-01

    Earth's land surface is characterized by tremendous natural heterogeneity and human-engineered modifications, both of which are challenging to represent in land surface models. Satellite remote sensing is often the most practical and effective method to observe the land surface over large geographical areas. Agricultural irrigation is an important human-induced modification to natural land surface processes, as it is pervasive across the world and because of its significant influence on the regional and global water budgets. In this article, irrigation is used as an example of a human-engineered, often unmodeled land surface process, and the utility of satellite soil moisture retrievals over irrigated areas in the continental US is examined. Such retrievals are based on passive or active microwave observations from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E), the Advanced Microwave Scanning Radiometer 2 (AMSR2), the Soil Moisture Ocean Salinity (SMOS) mission, WindSat and the Advanced Scatterometer (ASCAT). The analysis suggests that the skill of these retrievals for representing irrigation effects is mixed, with ASCAT-based products somewhat more skillful than SMOS and AMSR2 products. The article then examines the suitability of typical bias correction strategies in current land data assimilation systems when unmodeled processes dominate the bias between the model and the observations. Using a suite of synthetic experiments that includes bias correction strategies such as quantile mapping and trained forward modeling, it is demonstrated that the bias correction practices lead to the exclusion of the signals from unmodeled processes, if these processes are the major source of the biases. It is further shown that new methods are needed to preserve the observational information about unmodeled processes during data assimilation.

  19. Evaluating the utility of satellite soil moisture retrievals over irrigated areas and the ability of land data assimilation methods to correct for unmodeled processes

    NASA Astrophysics Data System (ADS)

    Kumar, S. V.; Peters-Lidard, C. D.; Santanello, J. A.; Reichle, R. H.; Draper, C. S.; Koster, R. D.; Nearing, G.; Jasinski, M. F.

    2015-11-01

    Earth's land surface is characterized by tremendous natural heterogeneity and human-engineered modifications, both of which are challenging to represent in land surface models. Satellite remote sensing is often the most practical and effective method to observe the land surface over large geographical areas. Agricultural irrigation is an important human-induced modification to natural land surface processes, as it is pervasive across the world and because of its significant influence on the regional and global water budgets. In this article, irrigation is used as an example of a human-engineered, often unmodeled land surface process, and the utility of satellite soil moisture retrievals over irrigated areas in the continental US is examined. Such retrievals are based on passive or active microwave observations from the Advanced Microwave Scanning Radiometer for the Earth Observing System (AMSR-E), the Advanced Microwave Scanning Radiometer 2 (AMSR2), the Soil Moisture Ocean Salinity (SMOS) mission, WindSat and the Advanced Scatterometer (ASCAT). The analysis suggests that the skill of these retrievals for representing irrigation effects is mixed, with ASCAT-based products somewhat more skillful than SMOS and AMSR2 products. The article then examines the suitability of typical bias correction strategies in current land data assimilation systems when unmodeled processes dominate the bias between the model and the observations. Using a suite of synthetic experiments that includes bias correction strategies such as quantile mapping and trained forward modeling, it is demonstrated that the bias correction practices lead to the exclusion of the signals from unmodeled processes, if these processes are the major source of the biases. It is further shown that new methods are needed to preserve the observational information about unmodeled processes during data assimilation.

  20. Comparison between antigen-capture ELISA and conventional methods used for titration of infectious bursal disease virus.

    PubMed

    Hassan, M K; Saif, Y M; Shawky, S

    1996-01-01

    Two antigen-capture enzyme-linked immunosorbent assays (polyclonal and monoclonal AC-ELISAs) were developed and evaluated for titration of infectious bursal disease viruses (IBDVs) propagated in different host systems, namely BGM-70 continuous cell line, primary chicken embryo fibroblast cells, and chicken bursa of Fabricius. The polyclonal system was more sensitive (P < 0.05) than the monoclonal system but both were specific as indicated by the negative results obtained with three non-IBDVs. The results revealed that the conventional systems used for titration of IBDVs (cell cultures and embryonating chicken eggs) were more sensitive than the polyclonal AC-ELISA.

  1. Concepts and applications for influenza antigenic cartography

    PubMed Central

    Cai, Zhipeng; Zhang, Tong; Wan, Xiu-Feng

    2011-01-01

    Influenza antigenic cartography projects influenza antigens into a two or three dimensional map based on immunological datasets, such as hemagglutination inhibition and microneutralization assays. A robust antigenic cartography can facilitate influenza vaccine strain selection since the antigenic map can simplify data interpretation through intuitive antigenic map. However, antigenic cartography construction is not trivial due to the challenging features embedded in the immunological data, such as data incompleteness, high noises, and low reactors. To overcome these challenges, we developed a computational method, temporal Matrix Completion-Multidimensional Scaling (MC-MDS), by adapting the low rank MC concept from the movie recommendation system in Netflix and the MDS method from geographic cartography construction. The application on H3N2 and 2009 pandemic H1N1 influenza A viruses demonstrates that temporal MC-MDS is effective and efficient in constructing influenza antigenic cartography. The web sever is available at http://sysbio.cvm.msstate.edu/AntigenMap. PMID:21761589

  2. A numerical method for retrieving high oxygen isotope temperatures from plutonic igneous rocks: An example from the Laramie Anorthosite Complex, Wyoming, USA

    SciTech Connect

    Farquhar, J.; Chacko, T. . Dept. of Geology); Frost, B.R. )

    1992-01-01

    The Sybille Pit is a late-stage magnetite-ilmenite-plagioclase-bearing differentiate of the Laramie Anorthosite with a wide range of grain sizes and modal mineralogy. This variability makes Sybille an ideal locality in which to study the factors that affect isotopic thermometry in plutonic environments. The authors have developed a numerical model based on isotope exchange trajectories that retrieves close to magmatic temperatures for samples from Sybille. This method is based on the premise that hand sample-scale sub-systems close to exchange with each other at temperatures that exceed those of the constituent minerals. The temperature of hand-sample scale closure is retrieved by back calculating the isotope exchange trajectories to the temperature at which two samples with widely different model compositions are in isotopic equilibrium. Application of these methods to samples from Sybille provides promising results. Whereas conventional isotopic thermometry of individual samples yields a wide range of temperatures ([approximately]600 to > 1000 C) depending on the mineral-pair chosen, application of this numerical model to multiple samples yields temperatures of 1,070 [+-] 100 C which corresponds closely to the inferred solidus for these rocks.

  3. A Framework Based on 2-D Taylor Expansion for Quantifying the Impacts of Subpixel Reflectance Variance and Covariance on Cloud Optical Thickness and Effective Radius Retrievals Based on the Bispectral Method

    NASA Technical Reports Server (NTRS)

    Zhang, Z.; Werner, F.; Cho, H.-M.; Wind, G.; Platnick, S.; Ackerman, A. S.; Di Girolamo, L.; Marshak, A.; Meyer, K.

    2016-01-01

    The bispectral method retrieves cloud optical thickness (t) and cloud droplet effective radius (re) simultaneously from a pair of cloud reflectance observations, one in a visible or near-infrared (VIS/NIR) band and the other in a shortwave infrared (SWIR) band. A cloudy pixel is usually assumed to be horizontally homogeneous in the retrieval. Ignoring subpixel variations of cloud reflectances can lead to a significant bias in the retrieved t and re. In the literature, the retrievals of t and re are often assumed to be independent and considered separately when investigating the impact of subpixel cloud reflectance variations on the bispectral method. As a result, the impact on t is contributed only by the subpixel variation of VIS/NIR band reflectance and the impact on re only by the subpixel variation of SWIR band reflectance. In our new framework, we use the Taylor expansion of a two-variable function to understand and quantify the impacts of subpixel variances of VIS/NIR and SWIR cloud reflectances and their covariance on the t and re retrievals. This framework takes into account the fact that the retrievals are determined by both VIS/NIR and SWIR band observations in a mutually dependent way. In comparison with previous studies, it provides a more comprehensive understanding of how subpixel cloud reflectance variations impact the t and re retrievals based on the bispectral method. In particular, our framework provides a mathematical explanation of how the subpixel variation in VIS/NIR band influences the re retrieval and why it can sometimes outweigh the influence of variations in the SWIR band and dominate the error in re retrievals, leading to a potential contribution of positive bias to the re retrieval. We test our framework using synthetic cloud fields from a large-eddy simulation and real observations from Moderate Resolution Imaging Spectroradiometer. The predicted results based on our framework agree very well with the numerical simulations. Our

  4. Retrieval of Trace gas and Aerosol Densities From Limb Scatter Measurements by OSIRIS on Odin Using a Modified Onion Peeling Method

    NASA Astrophysics Data System (ADS)

    Auvinen, H.; Oikarinen, L.; Kyrölä, E.; Odin Team,

    2001-12-01

    The Odin satellite, which carries two instruments, OSIRIS and SMR, was launched to a heliosyncronous orbit in February 2001. The observation time is divided between aeronomical and astronomical measurements. In aeronomy mode OSIRIS and SMR will scan the limb either in a continuous or in a stepwise manner from tangent altitudes of 60 (alternatively 120 km) to 7 km. OSIRIS includes an UV-visible spectrometer and an infrared imager. SMR is a sub-millimeter radiometer, which is used for both aeronomy and astronomy measurements. In this paper we present a Modified Onion Peeling (MOP) method to retrieve minor species densities from limb scatter measurements by OSIRIS. The goal is to retrieve vertical profiles of ozone, NO2, OClO and BrO density, and also aerosol and Rayleigh extinction. The need for absolute calibration of the radiance measurement is circumvented by dividing the data with a reference measurement made at a high tangent altitude by the same instrument. We approximate the atmosphere to be, at least in the first order, locally spherically symmetric. This leads to a non-linear inversion problem. Multiple scattering is taken into account by pre-calculated total to single scattering radiance ratios tabulated as a function of wavelength, tangent altitude, and several other relevant parameters. The inversion uses the whole UV-visible spectral range of OSIRIS. Several constituents are inverted simultaneously. We show preliminary retrieval results from selected OSIRIS measurements. Odin is a Swedish-led satellite project funded jointly by Sweden (SNSB), Canada (CSA), Finland (Tekes) and France (CNES).

  5. Flow cytometric titration of retroviral expression vectors: comparison of methods for analysis of immunofluorescence histograms derived from cells expressing low antigen levels.

    PubMed

    Sladek, T L; Jacobberger, J W

    1993-01-01

    Few quantitative studies addressing immunofluorescence histogram analysis have been published. One study by Overton (Cytometry 9:619-626, 1988) has shown threshold and histogram subtraction methods to be accurate for analysis of well-separated immunofluorescence distributions of positive and negative cells. An evaluation of methods to analyze immunofluorescence histograms when positive and negative immunofluorescence distributions overlap has not, to our knowledge, been reported. In this paper, data obtained from flow cytometry of immunofluorescently stained cells infected with recombinant retroviruses that produce a range of simian virus 40 large T antigen levels were analyzed by threshold, histogram subtraction, and distribution modeling methods. This analysis showed that as the separation between the immunofluorescence distributions of positive and negative cell populations decrease the best methods for histogram analysis are modeling followed, in order, by histogram subtraction, and threshold analysis.

  6. Iodine-filter-based mobile Doppler lidar to make continuous and full-azimuth-scanned wind measurements: data acquisition and analysis system, data retrieval methods, and error analysis.

    PubMed

    Wang, Zhangjun; Liu, Zhishen; Liu, Liping; Wu, Songhua; Liu, Bingyi; Li, Zhigang; Chu, Xinzhao

    2010-12-20

    An incoherent Doppler wind lidar based on iodine edge filters has been developed at the Ocean University of China for remote measurements of atmospheric wind fields. The lidar is compact enough to fit in a minivan for mobile deployment. With its sophisticated and user-friendly data acquisition and analysis system (DAAS), this lidar has made a variety of line-of-sight (LOS) wind measurements in different operational modes. Through carefully developed data retrieval procedures, various wind products are provided by the lidar, including wind profile, LOS wind velocities in plan position indicator (PPI) and range height indicator (RHI) modes, and sea surface wind. Data are processed and displayed in real time, and continuous wind measurements have been demonstrated for as many as 16 days. Full-azimuth-scanned wind measurements in PPI mode and full-elevation-scanned wind measurements in RHI mode have been achieved with this lidar. The detection range of LOS wind velocity PPI and RHI reaches 8-10 km at night and 6-8 km during daytime with range resolution of 10 m and temporal resolution of 3 min. In this paper, we introduce the DAAS architecture and describe the data retrieval methods for various operation modes. We present the measurement procedures and results of LOS wind velocities in PPI and RHI scans along with wind profiles obtained by Doppler beam swing. The sea surface wind measured for the sailing competition during the 2008 Beijing Olympics is also presented. The precision and accuracy of wind measurements are estimated through analysis of the random errors associated with photon noise and the systematic errors introduced by the assumptions made in data retrieval. The three assumptions of horizontal homogeneity of atmosphere, close-to-zero vertical wind, and uniform sensitivity are made in order to experimentally determine the zero wind ratio and the measurement sensitivity, which are important factors in LOS wind retrieval. Deviations may occur under certain

  7. Data generated from three quantitative mass spectral methods for the analysis of trivalent influenza vaccine antigens are compared.

    PubMed

    Smith, Daryl G S; Gingras, Geneviève; Aubin, Yves; Cyr, Terry D

    2016-12-01

    Herein we present the data necessary for generation of alternative means to produce equimolar mixtures of peptides ("Design and Expression of a QconCAT Protein to Validate Hi3 Protein Quantification of Influenza Vaccine Antigens" (D.G.S. Smith, G. Gingras, Y. Aubin, T.D. Cyr, 2016) [1]), such as QConCAT ("Trends in QconCATs for targeted proteomics" (J. Chen, I.V. Turko, 2014) [2] , "Natural flanking sequences for peptides included in a quantification concatamer internal standard" (C.S. Cheung, K.W. Anderson, M. Wang, I.V. Turko, 2015) [3]) and SpikeTides versus the label free Hi3 approach. The experimental design and the interpretation of results are discussed in the original article [1]. PMID:27656669

  8. Practical quantum retrieval games

    NASA Astrophysics Data System (ADS)

    Arrazola, Juan Miguel; Karasamanis, Markos; Lütkenhaus, Norbert

    2016-06-01

    Complex cryptographic protocols are often constructed from simpler building blocks. In order to advance quantum cryptography, it is important to study practical building blocks that can be used to develop new protocols. An example is quantum retrieval games (QRGs), which have broad applicability and have already been used to construct quantum money schemes. In this work, we introduce a general construction of quantum retrieval games based on the hidden matching problem and show how they can be implemented in practice using available technology. More precisely, we provide a general method to construct (1-out-of-k ) QRGs, proving that their cheating probabilities decrease exponentially in k . In particular, we define QRGs based on coherent states of light, which can be implemented even in the presence of experimental imperfections. Our results constitute a tool in the arsenal of the practical quantum cryptographer.

  9. Invasive brain-machine interfaces: a survey of paralyzed patients’ attitudes, knowledge and methods of information retrieval

    NASA Astrophysics Data System (ADS)

    Lahr, Jacob; Schwartz, Christina; Heimbach, Bernhard; Aertsen, Ad; Rickert, Jörn; Ball, Tonio

    2015-08-01

    Objective. Brain-machine interfaces (BMI) are an emerging therapeutic option that can allow paralyzed patients to gain control over assistive technology devices (ATDs). BMI approaches can be broadly classified into invasive (based on intracranially implanted electrodes) and noninvasive (based on skin electrodes or extracorporeal sensors). Invasive BMIs have a favorable signal-to-noise ratio, and thus allow for the extraction of more information than noninvasive BMIs, but they are also associated with the risks related to neurosurgical device implantation. Current noninvasive BMI approaches are typically concerned, among other issues, with long setup times and/or intensive training. Recent studies have investigated the attitudes of paralyzed patients eligible for BMIs, particularly patients affected by amyotrophic lateral sclerosis (ALS). These studies indicate that paralyzed patients are indeed interested in BMIs. Little is known, however, about the degree of knowledge among paralyzed patients concerning BMI approaches or about how patients retrieve information on ATDs. Furthermore, it is not yet clear if paralyzed patients would accept intracranial implantation of BMI electrodes with the premise of decoding improvements, and what the attitudes of a broader range of patients with diseases such as stroke or spinal cord injury are towards this new kind of treatment. Approach. Using a questionnaire, we surveyed 131 paralyzed patients for their opinions on invasive BMIs and their attitude toward invasive BMI treatment options. Main results. The majority of the patients knew about and had a positive attitude toward invasive BMI approaches. The group of ALS patients was especially open to the concept of BMIs. The acceptance of invasive BMI technology depended on the improvements expected from the technology. Furthermore, the survey revealed that for paralyzed patients, the Internet is an important source of information on ATDs. Significance. Websites tailored to

  10. A persistent scatterer method for retrieving accurate InSAR ground deformation map over vegetation-decorrelated areas

    NASA Astrophysics Data System (ADS)

    Chen, J.; Zebker, H. A.; Knight, R. J.

    2015-12-01

    InSAR is commonly used to measure surface deformation between different radar passes at cm-scale accuracy and m-scale resolution. However, InSAR measurements are often decorrelated due to vegetation growth, which greatly limits high quality InSAR data coverage. Here we present an algorithm for retrieving InSAR deformation measurements over areas with significant vegetation decorrelation through the use of adaptive interpolation between persistent scatterer (PS) pixels, those points at which surface scattering properties do not change much over time and thus decorrelation artifacts are minimal. The interpolation filter restores phase continuity in space and greatly reduces errors in phase unwrapping. We apply this algorithm to process L-band ALOS interferograms acquired over the San Luis Valley, Colorado and the Tulare Basin, California. In both areas, groundwater extraction for irrigation results in land deformation that can be detected using InSAR. We show that the PS-based algorithm reduces the artifacts from vegetation decorrelation while preserving the deformation signature. The spatial sampling resolution achieved over agricultural fields is on the order of hundreds of meters, usually sufficient for groundwater studies. The improved InSAR data allow us further to reconstruct the SBAS ground deformation time series and transform the measured deformation to head levels using the skeletal storage coefficient and time delay constant inferred from a joint InSAR-well data analysis. The resulting InSAR-head and well-head measurements in the San Luis valley show good agreement with primary confined aquifer pumping activities. This case study demonstrates that high quality InSAR deformation data can be obtained over vegetation-decorrrelated region if processed correctly.

  11. A Highly Selective and Sensitive Fluorescence Detection Method of Glyphosate Based on an Immune Reaction Strategy of Carbon Dot Labeled Antibody and Antigen Magnetic Beads.

    PubMed

    Wang, Duo; Lin, Bixia; Cao, Yujuan; Guo, Manli; Yu, Ying

    2016-08-01

    A sensitive fluorescence detection method for glyphosate (GLY) was established based on immune reaction. First, carbon dot labeled antibodies (lgG-CDs) which were able to specifically identify glyphosate were prepared with the environmentally friendly carbon dots (CDs) and glyphosate antibody (lgG). lgG-CDs could be used to in situ visualize the distribution of glyphosate in plant tissues. In order to eliminate the effects of excess lgG-CDs on the determination of GLY, antigen magnetic beads Fe3O4-GLY based on magnetic nanoparticles Fe3O4 and glyphosate were constructed and utilized to couple with the excess lgG-CDs. After magnetic separation to remove antigen magnetic beads, there was a linear relationship between the fluorescence intensity of lgG-CDs and the logarithmic concentration of glyphosate in the range of 0.01-80 μg/mL with a detection limit of 8 ng/mL. The method was used for the detection of glyphosate in Pearl River water, tea, and soil samples with satisfactory recovery ratio between 87.4% and 103.7%. PMID:27403652

  12. A Highly Selective and Sensitive Fluorescence Detection Method of Glyphosate Based on an Immune Reaction Strategy of Carbon Dot Labeled Antibody and Antigen Magnetic Beads.

    PubMed

    Wang, Duo; Lin, Bixia; Cao, Yujuan; Guo, Manli; Yu, Ying

    2016-08-01

    A sensitive fluorescence detection method for glyphosate (GLY) was established based on immune reaction. First, carbon dot labeled antibodies (lgG-CDs) which were able to specifically identify glyphosate were prepared with the environmentally friendly carbon dots (CDs) and glyphosate antibody (lgG). lgG-CDs could be used to in situ visualize the distribution of glyphosate in plant tissues. In order to eliminate the effects of excess lgG-CDs on the determination of GLY, antigen magnetic beads Fe3O4-GLY based on magnetic nanoparticles Fe3O4 and glyphosate were constructed and utilized to couple with the excess lgG-CDs. After magnetic separation to remove antigen magnetic beads, there was a linear relationship between the fluorescence intensity of lgG-CDs and the logarithmic concentration of glyphosate in the range of 0.01-80 μg/mL with a detection limit of 8 ng/mL. The method was used for the detection of glyphosate in Pearl River water, tea, and soil samples with satisfactory recovery ratio between 87.4% and 103.7%.

  13. Antigens and allergic asthma

    SciTech Connect

    Reed, C.E.; Swanson, M.C.

    1987-06-01

    There are few reliable epidemiologic data on the overall frequency and importance of allergy. We describe a practical method for quantifying the concentration of both amorphous and morphologically defined antigens in the air. A high volume air sampler is used to collect airborne particles and has a facility to separate samples into different particle sizes. Samples are tested for allergenic activity by radioallergosorbent test inhibition assay. Preliminary findings from studies of community wide, amorphous and common household allergens are reported.

  14. Intercomparison of single-frequency methods for retrieving a vertical rain profile from airborne or spaceborne radar data

    NASA Technical Reports Server (NTRS)

    Iguchi, Toshio; Meneghini, Robert

    1994-01-01

    This paper briefly reviews several single-frequency rain profiling methods for an airborne or spaceborne radar. The authors describe the different methods from a unified point of view starting from the basic differential equation. This facilitates the comparisons between the methods and also provides a better understanding of the physical and mathematical basis of the methods. The application of several methods to airborne radar data taken during the Convective and Precipitation/Electrification Experiment is shown. Finally, the authors consider a hybrid method that provides a smooth transition between the Hitschfeld-Bordan method, which performs well at low attenuations, and the surface reference method, for which the relative error decreases with increasing path attenuation.

  15. Accuracy of methods for calculating volumetric wear from coordinate measuring machine data of retrieved metal-on-metal hip joint implants.

    PubMed

    Lu, Zhen; McKellop, Harry A

    2014-03-01

    This study compared the accuracy and sensitivity of several numerical methods employing spherical or plane triangles for calculating the volumetric wear of retrieved metal-on-metal hip joint implants from coordinate measuring machine measurements. Five methods, one using spherical triangles and four using plane triangles to represent the bearing and the best-fit surfaces, were assessed and compared on a perfect hemisphere model and a hemi-ellipsoid model (i.e. unworn models), computer-generated wear models and wear-tested femoral balls, with point spacings of 0.5, 1, 2 and 3 mm. The results showed that the algorithm (Method 1) employing spherical triangles to represent the bearing surface and to scale the mesh to the best-fit surfaces produced adequate accuracy for the wear volume with point spacings of 0.5, 1, 2 and 3 mm. The algorithms (Methods 2-4) using plane triangles to represent the bearing surface and to scale the mesh to the best-fit surface also produced accuracies that were comparable to that with spherical triangles. In contrast, if the bearing surface was represented with a mesh of plane triangles and the best-fit surface was taken as a smooth surface without discretization (Method 5), the algorithm produced much lower accuracy with a point spacing of 0.5 mm than Methods 1-4 with a point spacing of 3 mm. PMID:24531891

  16. Accuracy of methods for calculating volumetric wear from coordinate measuring machine data of retrieved metal-on-metal hip joint implants.

    PubMed

    Lu, Zhen; McKellop, Harry A

    2014-03-01

    This study compared the accuracy and sensitivity of several numerical methods employing spherical or plane triangles for calculating the volumetric wear of retrieved metal-on-metal hip joint implants from coordinate measuring machine measurements. Five methods, one using spherical triangles and four using plane triangles to represent the bearing and the best-fit surfaces, were assessed and compared on a perfect hemisphere model and a hemi-ellipsoid model (i.e. unworn models), computer-generated wear models and wear-tested femoral balls, with point spacings of 0.5, 1, 2 and 3 mm. The results showed that the algorithm (Method 1) employing spherical triangles to represent the bearing surface and to scale the mesh to the best-fit surfaces produced adequate accuracy for the wear volume with point spacings of 0.5, 1, 2 and 3 mm. The algorithms (Methods 2-4) using plane triangles to represent the bearing surface and to scale the mesh to the best-fit surface also produced accuracies that were comparable to that with spherical triangles. In contrast, if the bearing surface was represented with a mesh of plane triangles and the best-fit surface was taken as a smooth surface without discretization (Method 5), the algorithm produced much lower accuracy with a point spacing of 0.5 mm than Methods 1-4 with a point spacing of 3 mm.

  17. Immunoblot for densitometric estimation of antibodies (IDEA): a useful method for quantification of intrathecally produced antibodies against individual antigens in infectious diseases of the central nervous system.

    PubMed

    Neumann, B; Ritter, K; Felgenhauer, K

    1991-11-01

    Intrathecally produced antibodies specific for the infectious agent can be shown by immunoblot. A quantification is practicable by titration. Densitometric evaluation of the immunoblot by a new technique, IDEA (immunoblot for densitometric estimation of antibodies), does not only render titration unnecessary, but also has the advantage of presenting the differentiated local immune response against individual antigens of the infectious agent. Preliminary studies for the densitometric evaluation were performed with a measles virus immunoblot which had been developed with a cerebrospinal fluid (CSF) sample of a patient suffering from multiple sclerosis containing high antibody titers. A peroxidase-labeled anti-immunoglobulin antibody had been added. The intensity of the color reaction on the membrane dependent on the antibody concentration follows a saturation kinetics comparable to the Michaelis-Menten kinetics in enzymology. Thus, indices for the intrathecal antibody synthesis of each individual viral antigen can be calculated by taking the permeability of the blood-CSF barrier into consideration. This method is illustrated in a patient with zoster meningoencephalitis.

  18. Immunohistowax processing, a new fixation and embedding method for light microscopy, which preserves antigen immunoreactivity and morphological structures: visualisation of dendritic cells in peripheral organs

    PubMed Central

    Pajak, B.; De Smedt, T.; Moulin, V.; De Trez, C.; Maldonado-Lopez, R.; Vansanten, G.; Briend, E.; Urbain, J.; Leo, O.; Moser, M.

    2000-01-01

    Aims—To describe a new fixation and embedding method for tissue samples, immunohistowax processing, which preserves both morphology and antigen immunoreactivity, and to use this technique to investigate the role of dendritic cells in the immune response in peripheral tissues. Methods—This technique was used to stain a population of specialised antigen presenting cells (dendritic cells) that have the unique capacity to sensitise naive T cells, and therefore to induce primary immune responses. The numbers of dendritic cells in peripheral organs of mice either untreated or injected with live Escherichia coli were compared. Results—Numbers of dendritic cells were greatly decreased in heart, kidney, and intestine after the inoculation of bacteria. The numbers of dendritic cells in the lung did not seem to be affected by the injection of E coli. However, staining of lung sections revealed that some monocyte like cells acquired morphological and phenotypic features of dendritic cells, and migrated into blood vessels. Conclusions—These observations suggest that the injection of bacteria induces the activation of dendritic cells in peripheral organs, where they play the role of sentinels, and/or their movement into lymphoid organs, where T cell priming is likely to occur. Key Words: dendritic cell • Escherichia coli • immunohistochemistry PMID:10961175

  19. NOPE: a new inversion method for the total attenuation profile retrieval in atmospheric tomography from space-borne experiments

    NASA Astrophysics Data System (ADS)

    Fussen, Didier

    1995-12-01

    The tomography of the Earth's atmosphere by the solar occultation method leads to a highly non-linear inverse problem if the full solar disc is used as the light source. Well known heuristic methods like Chahine's algorithm or onion peeling fail to solve the inversion. We present a new method referred to as NOPE (for natural orthogonal polynomial expansion) that addresses this class of inverse problems by focusing on the morphological content of the unknown profile and allowing also a fine tuning of the a priori information.

  20. Accuracy of Chlamydia trachomatis antigen detection methods in a low-prevalence population in a primary care setting.

    PubMed Central

    Gann, P H; Herrmann, J E; Candib, L; Hudson, R W

    1990-01-01

    We compared a direct fluorescent-antibody stain (DFA) and an enzyme immunoassay (EIA) with a standard cell culture technique for the detection of Chlamydia trachomatis infection in women in an urban family practice setting. We also evaluated a DFA sample in a commercial laboratory to determine the interlaboratory reliability of this test. There were 268 women in the study; the EIA provided a higher sensitivity (83 versus 50%) and a higher positive predictive value (83 versus 69%) than the DFA test and comparably high specificity (99 versus 98%). Concordance between the two laboratories on the DFA test was not high when data were adjusted for chance agreement (kappa coefficient = 0.64). DFA validity was optimal with an elementary body cutoff of greater than 5, while EIA validity was optimal at the recommended cutoff of 0.1 optical density unit. None of 11 women with negative cultures after treatment had false-positive antigen tests. False-negative results with both tests were associated with low culture inclusion counts but were not strongly associated with the presence or absence of symptoms, menses, pregnancy, or recent antibiotic use. False-positive results with EIA were seen only for three women who had a chief complaint of vaginal discharge. Although the positive predictive value of DFA could be increased in high-prevalence subpopulations, EIA was still more valid in two such groups: teenagers and prenatal patients. These results indicate that EIA might be preferable for low- or moderate-prevalence populations in primary care settings and that a falloff in DFA sensitivity could be explained by lower infection burdens in low-prevalence groups. PMID:2199520

  1. JURASSIC Retrieval Processing

    NASA Astrophysics Data System (ADS)

    Blank, J.; Ungermann, J.; Guggenmoser, T.; Kaufmann, M.; Riese, M.

    2012-04-01

    The Gimballed Limb Observer for Radiance Imaging in the Atmosphere (GLORIA) is an aircraft based infrared limb-sounder. This presentation will give an overview of the retrieval techniques used for the analysis of data produced by the GLORIA instrument. For data processing, the JUelich RApid Spectral SImulation Code 2 (JURASSIC2) was developed. It consists of a set of programs to retrieve atmospheric profiles from GLORIA measurements. The GLORIA Michelson interferometer can run with a wide range of parameters. In the dynamics mode, spectra are generate with a medium spectral and a very high temporal and spatial resolution. Each sample can contain thousands of spectral lines for each contributing trace gas. In the JURASSIC retrieval code this is handled by using a radiative transport model based on the Emissivity Growth Approximation. Deciding which samples should be included in the retrieval is a non-trivial task and requires specific domain knowledge. To ease this problem we developed an automatic selection program by analysing the Shannon information content. By taking into account data for all relevant trace gases and instrument effects, optimal integrated spectral windows are computed. This includes considerations for cross-influence of trace gases, which has non-obvious consequence for the contribution of spectral samples. We developed methods to assess the influence of spectral windows on the retrieval. While we can not exhaustively search the whole range of possible spectral sample combinations, it is possible to optimize information content using a genetic algorithm. The GLORIA instrument is mounted with a viewing direction perpendicular to the flight direction. A gimbal frame makes it possible to move the instrument 45° to both direction. By flying on a circular path, it is possible to generate images of an area of interest from a wide range of angles. These can be analyzed in a 3D-tomographic fashion, which yields superior spatial resolution along line of

  2. Vaccines and viral antigenic diversity.

    PubMed

    Mumford, J A

    2007-04-01

    Antigenic diversity among ribonucleic acid (RNA) viruses occurs as a result of rapid mutation during replication and recombination/reassortment between genetic material of related strains during co-infections. Variants which have a selective advantage in terms of ability to spread or to avoid host immunity become established within populations. Examples of antigenically diverse viruses include influenza, foot and mouth disease (FMD) and bluetongue (BT). Effective vaccination against such viruses requires surveillance programmes to monitor circulating serotypes and their evolution to ensure that vaccine strains match field viruses. A formal vaccine strain selection scheme for equine influenza has been established under the auspices of the World Organisation for Animal Health (OIE) based on an international surveillance programme. A regulatory framework has been put in place to allow rapid updating of vaccine strains withoutthe need to provide full registration data for licensing the updated vaccine. While there is extensive surveillance of FMD worldwide and antigenic and genetic characterisation of isolates, there is no formal vaccine strain selection system. A coordinated international effort has been initiated to agree harmonised approaches to virus characterisation which is aimed at providing the basis for an internationally agreed vaccine matching system for FMD supported by the OIE. The emergence and spread of BT in Europe have resulted in an intensification of vaccine evaluation in terms of safety and efficacy, particularly cross-protection within and between serotypes. The most important requirement for producing vaccines against viruses displaying antigenic diversity is a method of measuring antigenic distances between strains and developing an understanding of how these distances relate to cross-protection. Antigenic cartography, a new computational method of quantifying antigenic distances between strains has been applied to human and equine influenza to

  3. Two methods for retrieving UV index for all cloud conditions from sky imager products or total SW radiation measurements.

    PubMed

    Badosa, Jordi; Calbó, Josep; Mckenzie, Richard; Liley, Ben; González, Josep-Abel; Forgan, Bruce; Long, Charles N

    2014-01-01

    Cloud effects on UV Index (UVI) and total solar radiation (TR) as a function of cloud cover and sunny conditions (from sky images) as well as of solar zenith angle (SZA) are assessed. These analyses are undertaken for a southern-hemisphere mid-latitude site where a 10-years dataset is available. It is confirmed that clouds reduce TR more than UV, in particular for obscured Sun conditions, low cloud fraction (<60%) and large SZA (>60°). Similarly, local short-time enhancement effects are stronger for TR than for UV, mainly for visible Sun conditions, large cloud fraction and large SZA. Two methods to estimate UVI are developed: (1) from sky imaging cloud cover and sunny conditions, and (2) from TR measurements. Both methods may be used in practical applications, although Method 2 shows overall the best performance, as TR allows considering cloud optical properties. The mean absolute (relative) differences of Method 2 estimations with respect to measured values are 0.17 UVI units (6.7%, for 1 min data) and 0.79 Standard Erythemal Dose (SED) units (3.9%, for daily integrations). Method 1 shows less accurate results but it is still suitable to estimate UVI: mean absolute differences are 0.37 UVI units (15%) and 1.6 SED (8.0%).

  4. Two Methods for Retrieving UV Index for All Cloud Conditions from Sky Imager Products or Total SW Radiation Measurements

    SciTech Connect

    Badosa, Jordi; Calbo, J.; McKenzie, R. L.; Liley, Ben; Gonzalez, J. A.; Forgan, B. W.; Long, Charles N.

    2014-07-01

    In the present study, we assess the cloud effects on UV Index (UVI) and total solar radiation (TR) as a function of cloud cover estimations and sunny conditions (from sky imaging products) as well as of solar zenith angle (SZA). These analyses are undertaken for a southern-hemisphere mid-latitude site where a 10-years dataset is available. It is confirmed that clouds reduce TR more than UV, in particular for obscured Sun conditions, low cloud fraction (< 60%) and large SZA (> 60º). Similarly, clouds enhance TR more than UV, mainly for visible Sun conditions, large cloud fraction and large SZA. Two methods to estimate UVI are developed: 1) from sky imaging cloud cover and sunny conditions, and 2) from TR measurements. Both methods may be used in practical operational applications, although Method 2 shows overall the best performance, since TR allows accounting for cloud optical properties. The mean absolute differences of Method 2 estimations with respect to measured values are 0.17 UVI units (for 1-minute data) and 0.79 Standard Erythemal Dose (SED) units (for daily integrations). Method 1 shows less accurate results but it is still suitable to estimate UVI: mean absolute differences are 0.37 UVI units and 1.6 SED.

  5. Analyzing Document Retrievability in Patent Retrieval Settings

    NASA Astrophysics Data System (ADS)

    Bashir, Shariq; Rauber, Andreas

    Most information retrieval settings, such as web search, are typically precision-oriented, i.e. they focus on retrieving a small number of highly relevant documents. However, in specific domains, such as patent retrieval or law, recall becomes more relevant than precision: in these cases the goal is to find all relevant documents, requiring algorithms to be tuned more towards recall at the cost of precision. This raises important questions with respect to retrievability and search engine bias: depending on how the similarity between a query and documents is measured, certain documents may be more or less retrievable in certain systems, up to some documents not being retrievable at all within common threshold settings. Biases may be oriented towards popularity of documents (increasing weight of references), towards length of documents, favour the use of rare or common words; rely on structural information such as metadata or headings, etc. Existing accessibility measurement techniques are limited as they measure retrievability with respect to all possible queries. In this paper, we improve accessibility measurement by considering sets of relevant and irrelevant queries for each document. This simulates how recall oriented users create their queries when searching for relevant information. We evaluate retrievability scores using a corpus of patents from US Patent and Trademark Office.

  6. Use of In Situ Cloud Condensation Nuclei, Extinction, and Aerosol Size Distribution Measurements to Test a Method for Retrieving Cloud Condensation Nuclei Profiles From Surface Measurements

    NASA Technical Reports Server (NTRS)

    Ghan, Stephen J.; Rissman, Tracey A.; Ellman, Robert; Ferrare, Richard A.; Turner, David; Flynn, Connor; Wang, Jian; Ogren, John; Hudson, James; Jonsson, Haflidi H.; VanReken, Timothy; Flagan, Richard C.; Seinfeld, John H.

    2006-01-01

    If the aerosol composition and size distribution below cloud are uniform, the vertical profile of cloud condensation nuclei (CCN) concentration can be retrieved entirely from surface measurements of CCN concentration and particle humidification function and surface-based retrievals of relative humidity and aerosol extinction or backscatter. This provides the potential for long-term measurements of CCN concentrations near cloud base. We have used a combination of aircraft, surface in situ, and surface remote sensing measurements to test various aspects of the retrieval scheme. Our analysis leads us to the following conclusions. The retrieval works better for supersaturations of 0.1% than for 1% because CCN concentrations at 0.1% are controlled by the same particles that control extinction and backscatter. If in situ measurements of extinction are used, the retrieval explains a majority of the CCN variance at high supersaturation for at least two and perhaps five of the eight flights examined. The retrieval of the vertical profile of the humidification factor is not the major limitation of the CCN retrieval scheme. Vertical structure in the aerosol size distribution and composition is the dominant source of error in the CCN retrieval, but this vertical structure is difficult to measure from remote sensing at visible wavelengths.

  7. Kyoto islet isolation method: the optimized one for non-heart-beating donors with highly efficient islet retrieval.

    PubMed

    Okitsu, T; Matsumoto, S; Iwanaga, Y; Noguchi, H; Nagata, H; Yonekawa, Y; Maekawa, T; Tanaka, K

    2005-10-01

    The availability of pancreata for clinical cadaveric islet transplantation is restricted to non-heart-beating donors (NHBDs) in Japan. This forced us to modify the current standard islet isolation protocol that was made up for brain-dead donors and make it suitable for NHBDs. The Kyoto islet isolation method is the one with induction of several steps based on the ideas both already reported literally and invented originally by ourselves. Using this islet isolation method, we isolated islets from 13 human pancreata of NHBDs and transplanted 11 preparations to six type-1 diabetic patients. The rate to meet release criteria of Edmonton protocol was 84.6%. Establishment of this method allowed us to begin a clinical islet transplantation program in Japan and to continue to perform the preparation of islets from NHBDs with high rate to meet the release criteria of the Edmonton protocol.

  8. A Novel Method of Safely Measuring Influenza Virus Aerosol Using Antigen-Capture Enzyme-Linked Immunosorbent Assay for the Performance Evaluation of Protective Clothing Materials.

    PubMed

    Shimasaki, Noriko; Nojima, Yasuhiro; Okaue, Akira; Takahashi, Hitoshi; Kageyama, Tsutomu; Hamamoto, Itsuki; Shinohara, Katsuaki

    2016-01-01

    Currently, threats caused by pathogens are serious public health problems worldwide. Protective clothing is essential when one is treating infected patients or dealing with unknown pathogens. Therefore, it is necessary to evaluate the performance of protective clothing against pathogens. In Japan, some methods for evaluating the performance of protective clothing have been established in the Japanese Industrial Standards (JIS). However, a test method against virus aerosols has not been established. Because there is a risk of infection from a live virus during the test, it is necessary to devise a safe method for the virus-aerosol-based test. Here, we propose a new method of safely measuring virus aerosols for the performance evaluation of protective clothing materials. To ensure safety, an inactivated virus was used. As a model virus, the influenza virus was selected owing to the proper small diameter of the virus particles. To quantitatively measure the particle-amount of the inactivated influenza virus, we developed an antigen-capture enzyme-linked immunosorbent assay (ELISA) targeting the M1 protein. Furthermore, we evaluated two materials using our method. Significant differences in the protection performance against the virus aerosol were observed between different sample materials, thereby confirming the applicability of our new method for performance evaluation.

  9. Employing Multiple Representations for Chinese Information Retrieval.

    ERIC Educational Resources Information Center

    Kwok, K. L.

    1999-01-01

    Discusses information retrieval in the Chinese language and describes three representation methods for texts: 1-gram or character, bigram, and short-word. Describes a study that investigated using more than one method simultaneously to improve retrieval effectiveness and considers word segmentation and costs. (Author/LRW)

  10. Common antigens between hydatid cyst and cancers

    PubMed Central

    Daneshpour, Shima; Bahadoran, Mehran; Hejazi, Seyed Hossein; Eskandarian, Abas Ali; Mahmoudzadeh, Mehdi; Darani, Hossein Yousofi

    2016-01-01

    Background: Different research groups reported a negative correlation between cancers and parasitical infections. As an example, the prevalence of a hydatid cyst among patients with cancer was significantly lower than its prevalence among normal population. Tn antigens exist both in cancer and hydatid cyst. This common antigen may be involved in the effect of parasite on cancer growth. So in this work, common antigens between hydatid cyst and cancers have been investigated. Materials and Methods: Different hydatid cyst antigens including hydatid fluid, laminated and germinal layer antigens, and excretory secretory antigens of protoscolices were run in SDS PAGE and transferred to NCP paper. In western immunoblotting, those antigens were probed with sera of patients with different cancer and also sera of non-cancer patients. Also, cross reaction among excretory secretory products of cancer cells and antisera raised against different hydatid cyst antigen was investigated. Results: In western immunoblotting, antisera raised against laminated and germinal layers of hydatid cyst reacted with excretory secretory products of cancer cells. Also, a reaction was detected between hydatid cyst antigens and sera of patients with some cancers. Conclusion: Results of this work emphasize existence of common antigens between hydatid cyst and cancers. More investigation about these common antigens is recommended. PMID:26962511

  11. EVA Retriever Demonstration

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The EVA retriever is demonstrated in the Manipulator Development Facility (MDF). The retriever moves on the air bearing table 'searching' for its target, in this case tools 'dropped' by astronauts on orbit.

  12. Use of the maximum entropy method to retrieve the vertical atmospheric ozone profile and predict atmospheric ozone content

    NASA Technical Reports Server (NTRS)

    Turner, B. Curtis

    1992-01-01

    A method is developed for prediction of ozone levels in planetary atmospheres. This method is formulated in terms of error covariance matrices, and is associated with both direct measurements, a priori first guess profiles, and a weighting function matrix. This is described by the following linearized equation: y = A(matrix) x X + eta, where A is the weighting matrix and eta is noise. The problems to this approach are: (1) the A matrix is near singularity; (2) the number of unknowns in the profile exceeds the number of data points, therefore, the solution may not be unique; and (3) even if a unique solution exists, eta may cause the solution to be ill conditioned.

  13. PICTURES OF A SUSPECT-TRU RETRIEVAL

    SciTech Connect

    GADD, R.R.

    2007-05-24

    Retrieving ''suspect'' transuranic (TRU) waste from the Hanford Site's low-level waste burial grounds is a tall order, due to conditions that have changed as the work progresses. Project personnel developed several new methods for handling the waste that other retrieval operations may find useful. The Waste Retrieval Project is operated by Fluor Hanford, a prime contractor for the U.S. Department of Energy's Richland Operations Office since 1996.

  14. Inter-comparison of four remote sensing based surface energy balance methods to retrieve surface evapotranspiration and water stress of irrigated fields in semi-arid climate

    NASA Astrophysics Data System (ADS)

    Chirouze, J.; Boulet, G.; Jarlan, L.; Fieuzal, R.; Rodriguez, J. C.; Ezzahar, J.; Er-Raki, S.; Bigeard, G.; Merlin, O.; Garatuza-Payan, J.; Watts, C.; Chehbouni, G.

    2013-01-01

    Remotely sensed surface temperature can provide a good proxy for water stress level and is therefore particularly useful to estimate spatially distributed evapotranspiration. Instantaneous stress levels or instantaneous latent heat flux are deduced from the surface energy balance equation constrained by this equilibrium temperature. Pixel average surface temperature depends on two main factors: stress and vegetation fraction cover. Methods estimating stress vary according to the way they treat each factor. Two families of methods can be defined: the contextual methods, where stress levels are scaled on a given image between hot/dry and cool/wet pixels for a particular vegetation cover, and single-pixel methods which evaluate latent heat as the residual of the surface energy balance for one pixel independently from the others. Four models, two contextual (S-SEBI and a triangle method, inspired by Moran et al., 1994) and two single-pixel (TSEB, SEBS) are applied at seasonal scale over a four by four km irrigated agricultural area in semi-arid northern Mexico. Their performances, both at local and spatial standpoints, are compared relatively to energy balance data acquired at seven locations within the area, as well as a more complex soil-vegetation-atmosphere transfer model forced with true irrigation and rainfall data. Stress levels are not always well retrieved by most models, but S-SEBI as well as TSEB, although slightly biased, show good performances. Drop in model performances is observed when vegetation is senescent, mostly due to a poor partitioning both between turbulent fluxes and between the soil/plant components of the latent heat flux and the available energy. As expected, contextual methods perform well when extreme hydric and vegetation conditions are encountered in the same image (therefore, esp. in spring and early summer) while they tend to exaggerate the spread in water status in more homogeneous conditions (esp. in winter).

  15. Comparing Methods for Land Surface Temperature Retrieval over Heterogeneous Land Cover Using Landsat-5 TM Thermal Infrared Data

    NASA Astrophysics Data System (ADS)

    Windahl, E.; de Beurs, K.

    2014-12-01

    Among other applications, remotely sensed land surface temperature (LST) has become critical for monitoring the surface urban heat island (SUHI) effect in cities across the world. While daily MODIS thermal infrared data is invaluable for examining changes in LST over time, the large 1 km spatial resolution makes studying the spatial patterns of LST in a heterogeneous urban environment difficult. The 120 m spatial resolution of Landsat 4-5 TM, as well the archive of data stretching back to 1982, make Landsat 4-5 TM sensors valuable resources for thermal data, especially in urban areas. However, the difficulty accurately correcting for atmospheric effects with only one thermal band, as well as the necessity for a priori knowledge of land surface emissivity (LSE), mean it is underutilized. Research to determine best practices for deriving LST from Landsat TM data given homogenous, usually vegetated land cover is relatively extensive; however, the accuracy of these methods given heterogeneous land cover is less well known, especially given Land Surface Emissivity (LSE) calculations that often rely heavily on NDVI. In order to determine the best methodology for measuring LST across heterogeneous land cover in the central United States, this study derives LST from Landsat 5 TM band 6 for Oklahoma City and the surrounding countryside on a fall and a spring date using three different methods: no atmospheric correction, the radiative transfer equation, and the mono-window algorithm. With all three methods, the common NDVI-based approach for estimating LSE is used; a fourth LST calculation with no atmospheric correction and an assumed emissivity of one is therefore included as contrast. Using regression analysis, these four LST measurements are compared to air temperatures recorded concurrently by approximately 40 Oklahoma Mesonet stations across the study area, and results are broken down by land cover type to explore potential biases or variations in accuracy.

  16. Method of in situ retrieval of contaminants or other substances using a barrier system and leaching solutions

    DOEpatents

    Nickelson, Reva A.; Walsh, Stephanie; Richardson, John G.; Dick, John R.; Sloan, Paul A.

    2006-12-26

    Processes and methods relating to treating contaminants and collecting desired substances from a zone of interest using subterranean collection and containment barriers. Tubular casings having interlock structures are used to create subterranean barriers for containing and treating buried waste and its effluents. The subterranean barrier includes an effluent collection system. Treatment solutions provided to the zone of interest pass therethrough and are collected by the barrier and treated or recovered, allowing on-site remediation. Barrier components may be used to in the treatment by collecting or removing contaminants or other materials from the zone of interest.

  17. Evaluating the Effectiveness of Information Retrieval Systems Using Simulated Queries.

    ERIC Educational Resources Information Center

    Gordon, Michael D.

    1990-01-01

    Describes a simulation method for estimating recall and fallout in a document retrieval system. Earlier research on simulating document retrieval systems is reviewed, examples are presented of the current method, a probabilistic justification of the method is given, theoretical concerns dealing with retrieval precision are discussed, and further…

  18. A Variational Method to Retrieve the Extinction Profile in Liquid Clouds Using Multiple Field-of-View Lidar

    NASA Technical Reports Server (NTRS)

    Pounder, Nicola L.; Hogan, Robin J.; Varnai, Tamas; Battaglia, Alessandro; Cahalan, Robert F.

    2011-01-01

    While liquid clouds playa very important role in the global radiation budget, it's been very difficult to remotely determine their internal cloud structure. Ordinary lidar instruments (similar to radars but using visible light pulses) receive strong signals from such clouds, but the information is limited to a thin layer near the cloud boundary. Multiple field-of-view (FOV) lidars offer some new hope as they are able to isolate photons that were scattered many times by cloud droplets and penetrated deep into a cloud before returning to the instrument. Their data contains new information on cloud structure, although the lack of fast simulation methods made it challenging to interpret the observations. This paper describes a fast new technique that can simulate multiple-FOV lidar signals and can even estimate the way the signals would change in response to changes in cloud properties-an ability that allows quick refinements in our initial guesses of cloud structure. Results for a hypothetical airborne three-FOV lidar suggest that this approach can help determine cloud structure for a deeper layer in clouds, and can reliably determine the optical thickness of even fairly thick liquid clouds. The algorithm is also applied to stratocumulus observations by the 8-FOV airborne "THOR" lidar. These tests demonstrate that the new method can determine the depth to which a lidar provides useful information on vertical cloud structure. This work opens the way to exploit data from spaceborne lidar and radar more rigorously than has been possible up to now.

  19. A shape-based statistical method to retrieve 2D TRUS-MR slice correspondence for prostate biopsy

    NASA Astrophysics Data System (ADS)

    Mitra, Jhimli; Srikantha, Abhilash; Sidibé, Désiré; Martí, Robert; Oliver, Arnau; Lladó, Xavier; Ghose, Soumya; Vilanova, Joan C.; Comet, Josep; Meriaudeau, Fabrice

    2012-02-01

    This paper presents a method based on shape-context and statistical measures to match interventional 2D Trans Rectal Ultrasound (TRUS) slice during prostate biopsy to a 2D Magnetic Resonance (MR) slice of a pre-acquired prostate volume. Accurate biopsy tissue sampling requires translation of the MR slice information on the TRUS guided biopsy slice. However, this translation or fusion requires the knowledge of the spatial position of the TRUS slice and this is only possible with the use of an electro-magnetic (EM) tracker attached to the TRUS probe. Since, the use of EM tracker is not common in clinical practice and 3D TRUS is not used during biopsy, we propose to perform an analysis based on shape and information theory to reach close enough to the actual MR slice as validated by experts. The Bhattacharyya distance is used to find point correspondences between shape-context representations of the prostate contours. Thereafter, Chi-square distance is used to find out those MR slices where the prostates closely match with that of the TRUS slice. Normalized Mutual Information (NMI) values of the TRUS slice with each of the axial MR slices are computed after rigid alignment and consecutively a strategic elimination based on a set of rules between the Chi-square distances and the NMI leads to the required MR slice. We validated our method for TRUS axial slices of 15 patients, of which 11 results matched at least one experts validation and the remaining 4 are at most one slice away from the expert validations.

  20. A novel method to retrieve Aerosol Optical Thickness from high-resolution optical satellite images using an extended version of the Haze Optimized Transform (HOTBAR)

    NASA Astrophysics Data System (ADS)

    Wilson, Robin; Milton, Edward; Nield, Joanna

    2016-04-01

    Aerosol Optical Thickness (AOT) data has many important applications including atmospheric correction of satellite imagery and monitoring of particulate matter air pollution. Current data products are generally available at a kilometre-scale resolution, but many applications require far higher resolutions. For example, particulate matter concentrations vary on a metre-scale, and thus data products at a similar scale are required to provide accurate assessments of particle densities and allow effective monitoring of air quality and analysis of local air quality effects on health. A novel method has been developed which retrieves per-pixel AOT values from high-resolution (~30m) satellite data. This method is designed to work over a wide range of land covers - including both bright and dark surfaces - and requires only standard visible and near-infrared data, making it applicable to a range of data from sensors such as Landsat, SPOT and Sentinel-2. The method is based upon an extension of the Haze Optimized Transform (HOT). The HOT was originally designed for assessing areas of thick haze in satellite imagery by calculating a 'haziness' value for each pixel in an image as the distance from a 'Clear Line' in feature space, defined by the high correlation between visible bands. Here, we adapt the HOT method and use it to provide AOT data instead. Significant extensions include Monte Carlo estimation of the 'Clear Line', object-based correction for land cover, and estimation of AOT from the haziness values through radiative transfer modelling. This novel method will enable many new applications of AOT data that were impossible with previously available low-resolution data, and has the potential to contribute significantly to our understanding of the air quality on health, the accuracy of satellite image atmospheric correction and the role of aerosols in the climate system.

  1. Intercomparison of four remote-sensing-based energy balance methods to retrieve surface evapotranspiration and water stress of irrigated fields in semi-arid climate

    NASA Astrophysics Data System (ADS)

    Chirouze, J.; Boulet, G.; Jarlan, L.; Fieuzal, R.; Rodriguez, J. C.; Ezzahar, J.; Er-Raki, S.; Bigeard, G.; Merlin, O.; Garatuza-Payan, J.; Watts, C.; Chehbouni, G.

    2014-03-01

    Instantaneous evapotranspiration rates and surface water stress levels can be deduced from remotely sensed surface temperature data through the surface energy budget. Two families of methods can be defined: the contextual methods, where stress levels are scaled on a given image between hot/dry and cool/wet pixels for a particular vegetation cover, and single-pixel methods, which evaluate latent heat as the residual of the surface energy balance for one pixel independently from the others. Four models, two contextual (S-SEBI and a modified triangle method, named VIT) and two single-pixel (TSEB, SEBS) are applied over one growing season (December-May) for a 4 km × 4 km irrigated agricultural area in the semi-arid northern Mexico. Their performance, both at local and spatial standpoints, are compared relatively to energy balance data acquired at seven locations within the area, as well as an uncalibrated soil-vegetation-atmosphere transfer (SVAT) model forced with local in situ data including observed irrigation and rainfall amounts. Stress levels are not always well retrieved by most models, but S-SEBI as well as TSEB, although slightly biased, show good performance. The drop in model performance is observed for all models when vegetation is senescent, mostly due to a poor partitioning both between turbulent fluxes and between the soil/plant components of the latent heat flux and the available energy. As expected, contextual methods perform well when contrasted soil moisture and vegetation conditions are encountered in the same image (therefore, especially in spring and early summer) while they tend to exaggerate the spread in water status in more homogeneous conditions (especially in winter). Surface energy balance models run with available remotely sensed products prove to be nearly as accurate as the uncalibrated SVAT model forced with in situ data.

  2. The retrieval of a buried cylindrical obstacle by a constrained modified gradient method in the H-polarization case and for Maxwellian materials

    NASA Astrophysics Data System (ADS)

    Lambert, M.; Lesselier, D.; Kooij, B. J.

    1998-10-01

    The retrieval of an unknown, possibly inhomogeneous, penetrable cylindrical obstacle buried entirely in a known homogeneous half-space - the constitutive material parameters of the obstacle and of its embedding obey a Maxwell model - is considered from single- or multiple-frequency aspect-limited data collected by ideal sensors located in air above the embedding half-space, when a small number of time-harmonic transverse electric (TE)-polarized line sources - the magnetic field H is directed along the axis of the cylinder - is also placed in air. The wavefield is modelled from a rigorous H-field domain integral-differential formulation which involves the dot product of the gradients of the single component of H and of the Green function of the stratified environment times a scalar-valued contrast function which contains the obstacle parameters (the frequency-independent, position-dependent relative permittivity and conductivity). A modified gradient method is developed in order to reconstruct the maps of such parameters within a prescribed search domain from the iterative minimization of a cost functional which incorporates both the error in reproducing the data and the error on the field built inside this domain. Non-physical values are excluded and convergence reached by incorporating in the solution algorithm, from a proper choice of unknowns, the condition that the relative permittivity be larger than or equal to 1, and the conductivity be non-negative. The efficiency of the constrained method is illustrated from noiseless and noisy synthetic data acquired independently. The importance of the choice of the initial values of the sought quantities, the need for a periodic refreshment of the constitutive parameters to avoid the algorithm providing inconsistent results, and the interest of a frequency-hopping strategy to obtain finer and finer features of the obstacle when the frequency is raised, are underlined. It is also shown that though either the permittivity

  3. ARM Cloud Retrieval Ensemble Data Set (ACRED)

    SciTech Connect

    Zhao, C; Xie, S; Klein, SA; McCoy, R; Comstock, JM; Delanoë, J; Deng, M; Dunn, M; Hogan, RJ; Jensen, MP; Mace, GG; McFarlane, SA; O’Connor, EJ; Protat, A; Shupe, MD; Turner, D; Wang, Z

    2011-09-12

    This document describes a new Atmospheric Radiation Measurement (ARM) data set, the ARM Cloud Retrieval Ensemble Data Set (ACRED), which is created by assembling nine existing ground-based cloud retrievals of ARM measurements from different cloud retrieval algorithms. The current version of ACRED includes an hourly average of nine ground-based retrievals with vertical resolution of 45 m for 512 layers. The techniques used for the nine cloud retrievals are briefly described in this document. This document also outlines the ACRED data availability, variables, and the nine retrieval products. Technical details about the generation of ACRED, such as the methods used for time average and vertical re-grid, are also provided.

  4. A pragmatic method for electronic medical record-based observational studies: developing an electronic medical records retrieval system for clinical research

    PubMed Central

    Yamamoto, Keiichi; Sumi, Eriko; Yamazaki, Toru; Asai, Keita; Yamori, Masashi; Teramukai, Satoshi; Bessho, Kazuhisa; Yokode, Masayuki; Fukushima, Masanori

    2012-01-01

    Objective The use of electronic medical record (EMR) data is necessary to improve clinical research efficiency. However, it is not easy to identify patients who meet research eligibility criteria and collect the necessary information from EMRs because the data collection process must integrate various techniques, including the development of a data warehouse and translation of eligibility criteria into computable criteria. This research aimed to demonstrate an electronic medical records retrieval system (ERS) and an example of a hospital-based cohort study that identified both patients and exposure with an ERS. We also evaluated the feasibility and usefulness of the method. Design The system was developed and evaluated. Participants In total, 800 000 cases of clinical information stored in EMRs at our hospital were used. Primary and secondary outcome measures The feasibility and usefulness of the ERS, the method to convert text from eligible criteria to computable criteria, and a confirmation method to increase research data accuracy. Results To comprehensively and efficiently collect information from patients participating in clinical research, we developed an ERS. To create the ERS database, we designed a multidimensional data model optimised for patient identification. We also devised practical methods to translate narrative eligibility criteria into computable parameters. We applied the system to an actual hospital-based cohort study performed at our hospital and converted the test results into computable criteria. Based on this information, we identified eligible patients and extracted data necessary for confirmation by our investigators and for statistical analyses with our ERS. Conclusions We propose a pragmatic methodology to identify patients from EMRs who meet clinical research eligibility criteria. Our ERS allowed for the efficient collection of information on the eligibility of a given patient, reduced the labour required from the investigators and

  5. Protein antigen delivery by gene gun-mediated epidermal antigen incorporation (EAI).

    PubMed

    Scheiblhofer, Sandra; Ritter, Uwe; Thalhamer, Josef; Weiss, Richard

    2013-01-01

    The gene gun technology can not only be employed for efficient transfer of gene vaccines into upper layers of the skin, but also for application of protein antigens. As a tissue rich in professional antigen presenting cells, the skin represents an attractive target for immunizations. In this chapter we present a method for delivery of the model antigen ovalbumin into the skin of mice termed epidermal antigen incorporation and describe in detail how antigen-specific proliferation in draining lymph nodes can be followed by flow cytometry.

  6. Retrieving soil surface temperature under snowpack using special sensor microwave/imager brightness temperature in forested areas of Heilongjiang, China: an improved method

    NASA Astrophysics Data System (ADS)

    Zheng, Xingming; Li, Xiaofeng; Jiang, Tao; Ding, Yanling; Wu, Lili; Zhang, Shiyi; Zhao, Kai

    2016-04-01

    Soil surface temperature (Ts) is an important indicator of global temperature change and a key input parameter for retrieving land surface variables using remote sensing techniques. Due to the masking in the thermal infrared band and the scattering in the microwave band of snow, the temperature of soil surfaces covered by snow is difficult to infer from remote sensing data. We attempted to estimate Ts under snow cover using brightness temperature data from the special sensor microwave/imager. Ts under snow cover was underestimated due to the strong scattering effect of snow on upward soil microwave emissions at 37 GHz. The underestimated portion of Ts is related to snow properties, such as depth, grain size, and moisture. Based on the microwave emission model of layered snowpacks, the simulated results revealed a linear relationship between the underestimated Ts and the brightness temperature difference (TBD) at 19 and 37 GHz. When TBDs at 19 and 37 GHz were introduced to the Ts estimation method, accuracy improved, i.e., the root mean square error and bias of the estimated Ts decreased greatly, especially for dry snow. This improvement allows Ts estimation of snow-covered surfaces from 37 GHz microwave brightness temperature.

  7. Retrieving soil surface temperature under snowpack using special sensor microwave/imager brightness temperature in forested areas of Heilongjiang, China: an improved method

    NASA Astrophysics Data System (ADS)

    Zheng, Xingming; Li, Xiaofeng; Jiang, Tao; Ding, Yanling; Wu, Lili; Zhang, Shiyi; Zhao, Kai

    2016-04-01

    Soil surface temperature (Ts) is an important indicator of global temperature change and a key input parameter for retrieving land surface variables using remote sensing techniques. Due to the masking in the thermal infrared band and the scattering in the microwave band of snow, the temperature of soil surfaces covered by snow is difficult to infer from remote sensing data. We attempted to estimate Ts under snow cover using brightness temperature data from the special sensor microwave/imager. Ts under snow cover was underestimated due to the strong scattering effect of snow on upward soil microwave emissions at 37 GHz. The underestimated portion of Ts is related to snow properties, such as depth, grain size, and moisture. Based on the microwave emission model of layered snowpacks, the simulated results revealed a linear relationship between the underestimated Ts and the brightness temperature difference (TBD) at 19 and 37 GHz. When TBDs at 19 and 37 GHz were introduced to the Ts estimation method, accuracy improved, i.e., the root mean square error and bias of the estimated Ts decreased greatly, especially for dry snow. This improvement allows Ts estimation of snow-covered surfaces from 37 GHz microwave brightness temperature.

  8. The Ecosystem of Information Retrieval

    ERIC Educational Resources Information Center

    Rodriguez-Munoz, Jose-Vicente; Martinez-Mendez, Francisco-Javier; Pastor-Sanchez, Juan-Antonio

    2012-01-01

    Introduction: This paper presents an initial proposal for a formal framework that, by studying the metric variables involved in information retrieval, can establish the sequence of events involved and how to perform it. Method: A systematic approach from the equations of Shannon and Weaver to establish the decidability of information retrieval…

  9. Serum Antibody Repertoire Profiling Using In Silico Antigen Screen

    PubMed Central

    Liu, Xinyue; Hu, Qiang; Liu, Song; Tallo, Luke J.; Sadzewicz, Lisa; Schettine, Cassandra A.; Nikiforov, Mikhail; Klyushnenkova, Elena N.; Ionov, Yurij

    2013-01-01

    Serum antibodies are valuable source of information on the health state of an organism. The profiles of serum antibody reactivity can be generated by using a high throughput sequencing of peptide-coding DNA from combinatorial random peptide phage display libraries selected for binding to serum antibodies. Here we demonstrate that the targets of immune response, which are recognized by serum antibodies directed against sequential epitopes, can be identified using the serum antibody repertoire profiles generated by high throughput sequencing. We developed an algorithm to filter the results of the protein database BLAST search for selected peptides to distinguish real antigens recognized by serum antibodies from irrelevant proteins retrieved randomly. When we used this algorithm to analyze serum antibodies from mice immunized with human protein, we were able to identify the protein used for immunizations among the top candidate antigens. When we analyzed human serum sample from the metastatic melanoma patient, the recombinant protein, corresponding to the top candidate from the list generated using the algorithm, was recognized by antibodies from metastatic melanoma serum on the western blot, thus confirming that the method can identify autoantigens recognized by serum antibodies. We demonstrated also that our unbiased method of looking at the repertoire of serum antibodies reveals quantitative information on the epitope composition of the targets of immune response. A method for deciphering information contained in the serum antibody repertoire profiles may help to identify autoantibodies that can be used for diagnosing and monitoring autoimmune diseases or malignancies. PMID:23826227

  10. Serum Antibody Repertoire Profiling Using In Silico Antigen Screen.

    PubMed

    Liu, Xinyue; Hu, Qiang; Liu, Song; Tallo, Luke J; Sadzewicz, Lisa; Schettine, Cassandra A; Nikiforov, Mikhail; Klyushnenkova, Elena N; Ionov, Yurij

    2013-01-01

    Serum antibodies are valuable source of information on the health state of an organism. The profiles of serum antibody reactivity can be generated by using a high throughput sequencing of peptide-coding DNA from combinatorial random peptide phage display libraries selected for binding to serum antibodies. Here we demonstrate that the targets of immune response, which are recognized by serum antibodies directed against sequential epitopes, can be identified using the serum antibody repertoire profiles generated by high throughput sequencing. We developed an algorithm to filter the results of the protein database BLAST search for selected peptides to distinguish real antigens recognized by serum antibodies from irrelevant proteins retrieved randomly. When we used this algorithm to analyze serum antibodies from mice immunized with human protein, we were able to identify the protein used for immunizations among the top candidate antigens. When we analyzed human serum sample from the metastatic melanoma patient, the recombinant protein, corresponding to the top candidate from the list generated using the algorithm, was recognized by antibodies from metastatic melanoma serum on the western blot, thus confirming that the method can identify autoantigens recognized by serum antibodies. We demonstrated also that our unbiased method of looking at the repertoire of serum antibodies reveals quantitative information on the epitope composition of the targets of immune response. A method for deciphering information contained in the serum antibody repertoire profiles may help to identify autoantibodies that can be used for diagnosing and monitoring autoimmune diseases or malignancies. PMID:23826227

  11. Fuzzy Set Theoretical Approach to Document Retrieval.

    ERIC Educational Resources Information Center

    Radecki, Tadeusz

    1979-01-01

    Presents a new method of document retrieval based on the fundamental operations of fuzzy set theory. Basic notions are introduced. Then the syntax and semantics of the proposed language for document retrieval is given, and an algorithm allocating documents to particular queries is described and its properties are discussed. (Author/CWM)

  12. Applications of Optical Technology: Information Retrieval.

    ERIC Educational Resources Information Center

    O'Connor, Mary Ann

    1991-01-01

    Discusses applications of optical technology, especially CD-ROMs, to information management needs. Information retrieval problems are discussed; design questions that concern the format of the data, indexing methods, and retrieval capabilities are presented; the need for updates is considered; access requirements are discussed; and the importance…

  13. Organ-Specific Membrane Antigens

    PubMed Central

    Sell, K. W.; Mori, W.; Rack, J. H.; Gurner, B. W.; Coombs, R. R. A.

    1969-01-01

    A satisfactory system for testing the reaction of rabbit antisera with membrane antigens of human tissue cells is described. This method allows the differentiation between IgG and IgM antibodies and provides an extremely sensitive method for the detection of antigens on all cells including non-viable fixed cells. Anti-organ serum before selective absorption showed very little organ specificity in their reactions, but may be made specific by extensive absorption although often the resulting specific titre was very low. Organ-specific membrane antigens were also identified and shown to be represented on tumour cells, although in some cases such as the colon the reactions were weaker with tumour cells than with normal parenchymal cells of an organ. On the other hand, in one case of carcinoma of the kidney the organ-specific antigens were detectably stronger on tumour cells than on normal kidney cells. Preliminary studies on human ascitic tumour cells from 4 different cancer patients show that species-specific membrane antigens can be demonstrated. Unfortunately none of the cases were derived from organs whose origin could be identified with the antisera which had been prepared for this series of experiments. ImagesFigs. 2-3 PMID:5806432

  14. Evaluation of the performance of four methods for detection of hepatitis B surface antigen and their application for testing 116,455 specimens.

    PubMed

    Liu, Can; Chen, Tianbin; Lin, Jinpiao; Chen, Huijuan; Chen, Jing; Lin, Sheng; Yang, Bin; Shang, Hongyan; Ou, Qishui

    2014-02-01

    Hepatitis B surface antigen (HBsAg) is a crucial serum marker for the diagnosis of hepatitis B virus (HBV) infection. It is imperative to compare test results from different detection methods based on different principles. Four methods, chemiluminescent microparticle immunoassay (CMIA), electrochemiluminescent immunoassay (ECLIA), enzyme-linked immunosorbent assay (ELISA) and golden immunochromato-graphic assay (GICA) were applied to test the HBsAg level in 250 specimens. According to the EP12-A2 and EP15-A2 documents from Clinical and Laboratory Standards Institute (CLSI), the concentration at which repeated results are 50% positive (C50) of HBsAg detected by CMIA, ECLIA, ELISA and GICA was 0.05, 0.08, 0.15 and 15.0IU/ml, respectively. When the detection concentration of HBsAg was 0.5IU/ml, the imprecision degree of CMIA, ECLIA and ELISA was 8.1%, 5.9% and 14.9% respectively. When detecting high HBsAg level (≥20.0IU/ml) and HBsAg negative specimens, the consistency of the four methods was high, while for the low level (0.05-20.0IU/ml), the consistency was poor (except for the CMIA and ECLIA, P<0.05). When evaluation of the four methods in qualitative diagnosis of HBsAg level in the 116,455 specimens, there was no significant discrepancy among CMIA, CMIA and ECLIA, however, GICA was significantly different from the other 3 methods. Compared with CMIA, the false negative rate of ECLIA, ELISA and GICA was 0.2%, 1.3% and 12.3% respectively. In conclusion, GICA was only suitable for the preliminary screening of HBsAg positive individuals and ELISA can be applied to the qualitative diagnosis of HBsAg. Both CMIA and ECLIA were suitable for the quantitative determination of HBsAg.

  15. Identification of the antigen content of electroimmunoprecipitates.

    PubMed

    Beyer, N Helena; Heegaard, Niels H H

    2013-01-01

    Polyclonal antibodies including purified antibody fractions and animal or human antisera may react with unknown antigens or antigens other than their main specificity in reactions that are best visualized by gel electroimmunoprecipitation methods, e.g., when analyzing complex antigen mixtures. The great advantage of gel immunoprecipitation approaches is that each immunoprecipitate contains antigen in a pure form and that the precipitate is separated by position, shape, and size from other precipitates in the complex patterns of crossed immunoelectrophoresis. The identification of the antigen content of such immunoprecipitates is important but challenging because of the very stable, high affinity complex formation leading to precipitation in the gels. Here, we present detailed step-by-step recipes for identifying the antigen content of electroimmunoprecipitates.

  16. Impact of antigenic exposures and role of molecular blood grouping in enhancing transfusion safety in chronically transfused thalassemics

    PubMed Central

    Makroo, Raj Nath; Agrawal, Soma; Bhatia, Aakanksha; Chowdhry, Mohit; Thakur, Uday Kumar

    2016-01-01

    Background: Red cell alloimmunization is an acknowledged complication of blood transfusion. Current transfusion practices for thalassemia do not cater to this risk. Serological phenotyping is usually not reliable in these cases unless performed before the first transfusion. Under such circumstances, molecular blood grouping is an effective alternative. Aim: To perform molecular blood group genotyping in chronically transfused thalassemia patients and assess the risk of antigenic exposure and incidence of alloimmunization with current transfusion protocols. Materials and Methods: Molecular blood group genotyping was performed for 47 chronically transfused thalassemia patients. Their 1-year transfusion records were retrieved to assess the antigenic exposure and the frequency thereof. Results: Of 47 patients, 6 were already alloimmunized (3 with anti-E and 3 with anti-K) and were receiving the corresponding antigen negative units. We observed that random selection of ABO and Rh D matched units resulted in 57.7% ±8.26% chance of Rh and Kell phenotype matching also. Forty-four patients had received one or more antigenic exposures at least once. The 6 already alloimmunized patients were further exposed to antigens other than the ones they were immunized to. During the study period, only one patient developed an alloantibody, anti-E with exposure to antigens C (92%) and/or E (32%) at each transfusion. Conclusion: Several factors apart from mere antigen exposure may influence the development of alloimmunization as most of our patients received antigenic exposures but not alloimmunized. Our data provide an impetus for future large-scale studies to understand the development of alloimmunization in such patients. PMID:27605852

  17. Impact of antigenic exposures and role of molecular blood grouping in enhancing transfusion safety in chronically transfused thalassemics

    PubMed Central

    Makroo, Raj Nath; Agrawal, Soma; Bhatia, Aakanksha; Chowdhry, Mohit; Thakur, Uday Kumar

    2016-01-01

    Background: Red cell alloimmunization is an acknowledged complication of blood transfusion. Current transfusion practices for thalassemia do not cater to this risk. Serological phenotyping is usually not reliable in these cases unless performed before the first transfusion. Under such circumstances, molecular blood grouping is an effective alternative. Aim: To perform molecular blood group genotyping in chronically transfused thalassemia patients and assess the risk of antigenic exposure and incidence of alloimmunization with current transfusion protocols. Materials and Methods: Molecular blood group genotyping was performed for 47 chronically transfused thalassemia patients. Their 1-year transfusion records were retrieved to assess the antigenic exposure and the frequency thereof. Results: Of 47 patients, 6 were already alloimmunized (3 with anti-E and 3 with anti-K) and were receiving the corresponding antigen negative units. We observed that random selection of ABO and Rh D matched units resulted in 57.7% ±8.26% chance of Rh and Kell phenotype matching also. Forty-four patients had received one or more antigenic exposures at least once. The 6 already alloimmunized patients were further exposed to antigens other than the ones they were immunized to. During the study period, only one patient developed an alloantibody, anti-E with exposure to antigens C (92%) and/or E (32%) at each transfusion. Conclusion: Several factors apart from mere antigen exposure may influence the development of alloimmunization as most of our patients received antigenic exposures but not alloimmunized. Our data provide an impetus for future large-scale studies to understand the development of alloimmunization in such patients.

  18. Reconstructed key frame and object motion based video retrieval

    NASA Astrophysics Data System (ADS)

    Hu, Shuangyan; Li, Junshan; Li, Kun; Wang, Rui; Yang, Weijun

    2007-11-01

    This paper proposes a video retrieval scheme which can retrieve desired video clips from video databases using color and object motion. The retrieval method includes two steps. In the first step, get the Intra picture frames (I-frames) set from the query MPEG video and reconstruct the key frame of the video based on the set. Then, the video retrieval equals to the retrieval of the reconstructed key frame(R-key frame) and can be easily performed according the methods of content based image retrieval. The second step, the local object motion information that is local motion vector field, is extracted from the video clips set which is the result of the first step, and the final similarity of videos is measured based on the constructed directional histogram. Experimental results show that the proposed two-step retrieval method performed excellently for video retrieval.

  19. Using Sequence Data To Infer the Antigenicity of Influenza Virus

    PubMed Central

    Sun, Hailiang; Yang, Jialiang; Zhang, Tong; Long, Li-Ping; Jia, Kun; Yang, Guohua; Webby, Richard J.; Wan, Xiu-Feng

    2013-01-01

    ABSTRACT The efficacy of current influenza vaccines requires a close antigenic match between circulating and vaccine strains. As such, timely identification of emerging influenza virus antigenic variants is central to the success of influenza vaccination programs. Empirical methods to determine influenza virus antigenic properties are time-consuming and mid-throughput and require live viruses. Here, we present a novel, experimentally validated, computational method for determining influenza virus antigenicity on the basis of hemagglutinin (HA) sequence. This method integrates a bootstrapped ridge regression with antigenic mapping to quantify antigenic distances by using influenza HA1 sequences. Our method was applied to H3N2 seasonal influenza viruses and identified the 13 previously recognized H3N2 antigenic clusters and the antigenic drift event of 2009 that led to a change of the H3N2 vaccine strain. PMID:23820391

  20. Query Specific Rank Fusion for Image Retrieval.

    PubMed

    Zhang, Shaoting; Yang, Ming; Cour, Timothee; Yu, Kai; Metaxas, Dimitris N

    2015-04-01

    Recently two lines of image retrieval algorithms demonstrate excellent scalability: 1) local features indexed by a vocabulary tree, and 2) holistic features indexed by compact hashing codes. Although both of them are able to search visually similar images effectively, their retrieval precision may vary dramatically among queries. Therefore, combining these two types of methods is expected to further enhance the retrieval precision. However, the feature characteristics and the algorithmic procedures of these methods are dramatically different, which is very challenging for the feature-level fusion. This motivates us to investigate how to fuse the ordered retrieval sets, i.e., the ranks of images, given by multiple retrieval methods, to boost the retrieval precision without sacrificing their scalability. In this paper, we model retrieval ranks as graphs of candidate images and propose a graph-based query specific fusion approach, where multiple graphs are merged and reranked by conducting a link analysis on a fused graph. The retrieval quality of an individual method is measured on-the-fly by assessing the consistency of the top candidates' nearest neighborhoods. Hence, it is capable of adaptively integrating the strengths of the retrieval methods using local or holistic features for different query images. This proposed method does not need any supervision, has few parameters, and is easy to implement. Extensive and thorough experiments have been conducted on four public datasets, i.e., the UKbench, Corel-5K, Holidays and the large-scale San Francisco Landmarks datasets. Our proposed method has achieved very competitive performance, including state-of-the-art results on several data sets, e.g., the N-S score 3.83 for UKbench. PMID:26353295

  1. Minor histocompatibility antigens: past, present, and future.

    PubMed

    Spierings, Eric

    2014-10-01

    Minor histocompatibility (H) antigens are key molecules driving allo-immune responses in both graft-versus-host-disease (GvHD) and in graft-versus-leukemia (GvL) reactivity in human leukocyte antigen (HLA)-matched hematopoietic stem-cell transplantation (HSCT). Dissection of the dual function of minor H antigens became evident through their different modes of tissue and cell expression, i.e. hematopoietic system-restricted or broad. Broadly expressed minor H antigens can cause both GvHD and GvL effects, while hematopoietic system-restricted minor H antigens are more prone to induce GvL responses. This phenomenon renders the latter group of minor H antigens as curative tools for HSCT-based immunotherapy of hematological malignancies and disorders, in which minor H antigen-specific responses are enhanced in order to eradicate the malignant cells. This article describes the immunogenetics of minor H antigens and methods that have been developed to identify them. Moreover, it summarizes the clinical relevance of minor H antigens in transplantation, with special regards to allogeneic HSCT and solid-organ transplantation.

  2. Whole-cell antigenicity data support sequence-based kinetoplastid taxonomy.

    PubMed

    Couvreur, Bernard

    2013-04-01

    Early immunological data, obtained by immunodiffusion and immunoelectrophoresis, on the whole-cell antigenicity of kinetoplastid protozoa were retrieved and used to construct a dendrogram of antigenic distances. Remarkably, they supported the same taxonomic conclusions as analyses based on DNA and protein sequence data.

  3. Günter tulip filter retrieval experience: predictors of successful retrieval.

    PubMed

    Turba, Ulku Cenk; Arslan, Bulent; Meuse, Michael; Sabri, Saher; Macik, Barbara Gail; Hagspiel, Klaus D; Matsumoto, Alan H; Angle, John F

    2010-08-01

    We report our experience with Günter Tulip filter placement indications, retrievals, and procedural problems, with emphasis on alternative retrieval techniques. We have identified 92 consecutive patients in whom a Günter Tulip filter was placed and filter removal attempted. We recorded patient demographic information, filter placement and retrieval indications, procedures, standard and nonstandard filter retrieval techniques, complications, and clinical outcomes. The mean time to retrieval for those who experienced filter strut penetration was statistically significant [F(1,90) = 8.55, p = 0.004]. Filter strut(s) IVC penetration and successful retrieval were found to be statistically significant (p = 0.043). The filter hook-IVC relationship correlated with successful retrieval. A modified guidewire loop technique was applied in 8 of 10 cases where the hook appeared to penetrate the IVC wall and could not be engaged with a loop snare catheter, providing additional technical success in 6 of 8 (75%). Therefore, the total filter retrieval success increased from 88 to 95%. In conclusion, the Günter Tulip filter has high successful retrieval rates with low rates of complication. Additional maneuvers such as a guidewire loop method can be used to improve retrieval success rates when the filter hook is endothelialized.

  4. Hepatitis C virus (HCV) Infection Rate among Seronegative Hemodialysis Patients Screened by Two Methods; HCV Core Antigen and Polymerase Chain Reaction

    PubMed Central

    Moini, Maryam; Ziyaeyan, Mazyar; Aghaei, Shapoor; Sagheb, Mohammad Mahdi; Taghavi, Seyed Alireza; Moeini, Mahsa; Jamalidoust, Marzieh; Hamidpour, Laleh

    2013-01-01

    Background End-stage renal disease patients on chronic hemodialysis are among high risk groups for hepatitis C virus (HCV) infection for whom routine HCV screening is recommended. Anti-HCV antibody (ab) testing may not be reliable to detect all infected cases because of the blunted ab response due to depressed immune state in these patients. Using a more reliable, cost-effective and non-complex HCV screening test may be necessary in this group of patients for case finding and management, and also for prevention of infection spread. Objectives The aim of this study was to find the prevalence of HCV infection in HCV ab negative hemodialysis patients by Real time PCR and total HCV core antigen (ag) test and comparing the results of the two tests. Patients and Methods From a single hemodialysis center, 181 anti- HCV ab negative patients were screened by total HCV core ag using an ELISA kit. Real time PCR was used for determination of the virus and viral load quantity. Results Among the 181 anti-HCV ab negative patients, 13 (7.2%) were positive for HCV core ag and 11 (6%) had detectable HCV RNA with a range of 40-336543 IU/ml by PCR. The two tests had a high measurement agreement (Kappa=0.82, P<0.001). Of the 13 patients with positive HCV core ag test results, 3 were negative for HCV RNA. Considering real time PCR for HCV RNA as the gold standard for HCV infection determination in this patient population, HCV core ag assay yielded a sensitivity of 90.9%, specificity of 98.2%, positive predictive value of 76.9% and negative predictive value of 99.4%. Discussion The rate of HCV infection among HCV ab negative hemodialysis patients was high. HCV core ag testing could be used as a sensitive method for HCV infection screening in this group of patients. PMID:24032048

  5. Knowledge Retrieval Solutions.

    ERIC Educational Resources Information Center

    Khan, Kamran

    1998-01-01

    Excalibur RetrievalWare offers true knowledge retrieval solutions. Its fundamental technologies, Adaptive Pattern Recognition Processing and Semantic Networks, have capabilities for knowledge discovery and knowledge management of full-text, structured and visual information. The software delivers a combination of accuracy, extensibility,…

  6. RETRIEVAL EVENTS EVALUATION

    SciTech Connect

    T. Wilson

    1999-11-12

    The purpose of this analysis is to evaluate impacts to the retrieval concept presented in the Design Analysis ''Retrieval Equipment and Strategy'' (Reference 6), from abnormal events based on Design Basis Events (DBE) and Beyond Design Basis Events (BDBE) as defined in two recent analyses: (1) DBE/Scenario Analysis for Preclosure Repository Subsurface Facilities (Reference 4); and (2) Preliminary Preclosure Design Basis Event Calculations for the Monitored Geologic Repository (Reference 5) The objective of this task is to determine what impacts the DBEs and BDBEs have on the equipment developed for retrieval. The analysis lists potential impacts and recommends changes to be analyzed in subsequent design analyses for developed equipment, or recommend where additional equipment may be needed, to allow retrieval to be performed in all DBE or BDBE situations. This analysis supports License Application design and therefore complies with the requirements of Systems Description Document input criteria comparison as presented in Section 7, Conclusions. In addition, the analysis discusses the impacts associated with not using concrete inverts in the emplacement drifts. The ''Retrieval Equipment and Strategy'' analysis was based on a concrete invert configuration in the emplacement drift. The scope of the analysis, as presented in ''Development Plan for Retrieval Events Evaluation'' (Reference 3) includes evaluation and criteria of the following: Impacts to retrieval from the emplacement drift based on DBE/BDBEs, and changes to the invert configuration for the preclosure period. Impacts to retrieval from the main drifts based on DBE/BDBEs for the preclosure period.

  7. Retrieval of Emotional Memories

    ERIC Educational Resources Information Center

    Buchanan, Tony W.

    2007-01-01

    Long-term memories are influenced by the emotion experienced during learning as well as by the emotion experienced during memory retrieval. The present article reviews the literature addressing the effects of emotion on retrieval, focusing on the cognitive and neurological mechanisms that have been revealed. The reviewed research suggests that the…

  8. Data Compression in Full-Text Retrieval Systems.

    ERIC Educational Resources Information Center

    Bell, Timothy C.; And Others

    1993-01-01

    Describes compression methods for components of full-text systems such as text databases on CD-ROM. Topics discussed include storage media; structures for full-text retrieval, including indexes, inverted files, and bitmaps; compression tools; memory requirements during retrieval; and ranking and information retrieval. (Contains 53 references.)…

  9. Compact binary hashing for music retrieval

    NASA Astrophysics Data System (ADS)

    Seo, Jin S.

    2014-03-01

    With the huge volume of music clips available for protection, browsing, and indexing, there is an increased attention to retrieve the information contents of the music archives. Music-similarity computation is an essential building block for browsing, retrieval, and indexing of digital music archives. In practice, as the number of songs available for searching and indexing is increased, so the storage cost in retrieval systems is becoming a serious problem. This paper deals with the storage problem by extending the supervector concept with the binary hashing. We utilize the similarity-preserving binary embedding in generating a hash code from the supervector of each music clip. Especially we compare the performance of the various binary hashing methods for music retrieval tasks on the widely-used genre dataset and the in-house singer dataset. Through the evaluation, we find an effective way of generating hash codes for music similarity estimation which improves the retrieval performance.

  10. Retrieval of stratospheric O3, HNO3, and ClONO2 profiles from 1992 MIPAS-B limb emission spectra: method, results, and error analysis

    NASA Astrophysics Data System (ADS)

    Clarmann, T. von; Fischer, H.; Friedl-Vallon, F.; Linden, A.; Oelhaf, H.; Piesch, C.; Seefeldner, M.; Völker, W.

    1993-11-01

    Within the framework of the European Arctic Stratospheric Ozone Experiment, two flights of the balloon-borne MIPAS-B limb emission spectrometer were performed in the Arctic stratosphere from Kiruna, northern Sweden. During the early hours of January 13 and the night from March 14 to March 15, 1992, several limb sequences of infrared spectra were recorded which have permitted the retrieval of vertical profiles of many trace gases relevant for ozone chemistry. In the present work, the retrieval strategy, error estimation strategy, and resulting profiles of O3, HNO3, and ClONO2 are reported. The data analysis procedure, consisting of data preprocessing including calibration, analysis of auxiliary data including temperature profiles and line of sight determination, and retrieval of trace gas profiles, is described in detail. The last is carried out by means of multiparameter nonlinear least squares fitting in combination with onion peeling. An astonishingly high ClONO2 amount of 2.6 ppb by volume at about 19-km altitude was inferred for the March flight. A rigorous error analysis, which takes into account systematic and random errors and their often nonlinear impact on the results, proves the significance of the retrieved trace gas profiles.

  11. Efficient Graffiti Image Retrieval

    SciTech Connect

    Yang, Chunlei; Wong, Pak C.; Ribarsky, William; Fan, Jianping

    2012-07-05

    Research of graffiti character recognition and retrieval, as a branch of traditional optical character recognition (OCR), has started to gain attention in recent years. We have investigated the special challenge of the graffiti image retrieval problem and propose a series of novel techniques to overcome the challenges. The proposed bounding box framework locates the character components in the graffiti images to construct meaningful character strings and conduct image-wise and semantic-wise retrieval on the strings rather than the entire image. Using real world data provided by the law enforcement community to the Pacific Northwest National Laboratory, we show that the proposed framework outperforms the traditional image retrieval framework with better retrieval results and improved computational efficiency.

  12. Challenges in Web Information Retrieval

    NASA Astrophysics Data System (ADS)

    Arora, Monika; Kanjilal, Uma; Varshney, Dinesh

    The major challenge in information access is the rich data available for information retrieval, evolved to provide principle approaches or strategies for searching. The search has become the leading paradigm to find the information on World Wide Web. For building the successful web retrieval search engine model, there are a number of challenges that arise at the different levels where techniques, such as Usenet, support vector machine are employed to have a significant impact. The present investigations explore the number of problems identified its level and related to finding information on web. This paper attempts to examine the issues by applying different methods such as web graph analysis, the retrieval and analysis of newsgroup postings and statistical methods for inferring meaning in text. We also discuss how one can have control over the vast amounts of data on web, by providing the proper address to the problems in innovative ways that can extremely improve on standard. The proposed model thus assists the users in finding the existing formation of data they need. The developed information retrieval model deals with providing access to information available in various modes and media formats and to provide the content is with facilitating users to retrieve relevant and comprehensive information efficiently and effectively as per their requirements. This paper attempts to discuss the parameters factors that are responsible for the efficient searching. These parameters can be distinguished in terms of important and less important based on the inputs that we have. The important parameters can be taken care of for the future extension or development of search engines

  13. A Dermatopathologist's Guide to Troubleshooting Immunohistochemistry Part 1: Methods and Pitfalls.

    PubMed

    Marsch, Amanda F; Truong, Jonathan N; McPherson, Melissa M; Junkins-Hopkins, Jacqueline M; Elston, Dirk M

    2015-08-01

    Immunohistochemistry (IHC) is a method by which specific target antigens can be detected in formalin-fixed paraffin-embedded tissue and involves the use of monoclonal or polyclonal antibodies; visualization of specific tissue antigens is achieved through an enzymatic reaction that transforms a colorless chromogen to a colored one. These enzymes may be attached to the antibody through a protein-ligand method (eg, biotin-avidin or biotin-streptavidin) or through a secondary antibody. Epitopes that are masked by protein linkage during formalin fixation are unmasked using a retrieval system that either uses heat (heat-induced epitope retrieval) or proteolytic enzymes (proteolytic-induced epitope retrieval). Part 1 of this review will focus and elaborate on the available methodologies for IHC testing, common problems inherent to each technique, and how they can be resolved. Part 2 will focus on common problems and artifacts encountered during IHC staining, likely causes, and methods for addressing each problem.

  14. A rapid and sensitive method based on magnetic beads for the detection of hepatitis B virus surface antigen in human serum.

    PubMed

    Ren, Zhi-Qi; Liu, Tian-Cai; Hou, Jing-Yuan; Chen, Mei-Jun; Chen, Zhen-Hua; Lin, Guan-Feng; Wu, Ying-Song

    2014-09-01

    Current clinically assays, such as enzyme-linked immunosorbent assay and chemiluminescence immunoassay, for hepatitis B surface antigen (HBsAg) are inferior in terms of either sensitivity and accuracy or rapid and high-throughput analysis. A novel assay based on magnetic beads and time-resolved fluoroimmunoassay was developed for the quantitative determination of HBsAg in human serum. HBsAg was captured using two types of anti-HBsAg monoclonal antibodies (B028, S015) immobilized on to magnetic beads and detected using europium-labeled anti-HBsAg polyclonal detection antibody. Finally, the assay yielded a high sensitivity (0.02 IU/mL) and a wide dynamic range (0.02-700 IU/mL) for HBsAg when performed under optimal conditions. Satisfactory accuracy, recovery and specificity were also demonstrated. The intra- and interassay coefficients of variation were 4.7-8.7% and 3.8-7.5%, respectively. The performance of this assay was further assessed against a well-established commercial chemiluminescence immunoassay kit with 399 clinical serum samples. It was revealed that the test results for the two methods were in good correlation (Y = 1.182X - 0.017, R = 0.989). In the current study, we demonstrated that this novel time-resolved fluoroimmunoassay could be used: as a highly sensitive, automated and high-throughput immunoassay for the diagnosis of acute or chronic hepatitis B virus infection; for the screening of blood or organ donors; and for the surveillance of persons at risk of acquiring or transmitting hepatitis B virus.

  15. Characterization of swine leukocyte antigen (SLA) polymorphism by sequence-based and PCR-SSP methods in Chinese Bama miniature pigs.

    PubMed

    Gao, Caixia; Jiang, Qian; Guo, Dongchun; Liu, Jiasen; Han, Lingxia; Qu, Liandong

    2014-07-01

    The highly polymorphic swine leukocyte antigen (SLA) genes have been repeatedly shown to influence swine immune traits, disease resistance, vaccine responsiveness and tumour penetrance. Analysis of the SLA diversity in as many pig breeds as possible is important to clarify the relationships between SLA genes and diseases or traits, and develop these pigs as valuable animal models for biomedical research. The Chinese Bama miniature pig breed is an economically significant breed that is available at several research institutions in China. In this study, we identified a total of 32 alleles at five polymorphic SLA loci (SLA-1, SLA-3, SLA-2, DRB1 and DQB1) representing nine class I and seven class II haplotypes using the reverse transcription polymerase chain reaction (RT-PCR) sequence-based typing (SBT) method. The possible functional sites of the SLA genes were predicted and analyzed by comparison with those of the human and mouse. Based on the sequence information, we subsequently developed a rapid PCR-based typing assay using sequence-specific primers (PCR-SSP) to efficiently follow the SLA types of the progeny. In the studied cohort (2n = 562), the most prevalent Haplotype Hp-35.6 (SLA-1(∗)1201, SLA-1(∗)1301-SLA-3(∗)0502-SLA-2(∗)1001-DRB1(∗)0501-DQB1(∗)0801) was identified in 182 Bama pigs with a frequency of 32.38%. The presence of the duplicated SLA-1 locus was confirmed in five of the class I haplotypes. Moreover, we identified two crossovers within the class I region and one between the class I and class II regions, which corresponded to recombination frequencies of 0.36% and 0.18%, respectively. The information of this study is essential for an understanding of the SLA allelic architecture and diversity, and it will be helpful for studying the adaptive immune response and further developing the more effective vaccines in the context of SLA specificities.

  16. Topological Aspects of Information Retrieval.

    ERIC Educational Resources Information Center

    Egghe, Leo; Rousseau, Ronald

    1998-01-01

    Discusses topological aspects of theoretical information retrieval, including retrieval topology; similarity topology; pseudo-metric topology; document spaces as topological spaces; Boolean information retrieval as a subsystem of any topological system; and proofs of theorems. (LRW)

  17. A computational framework for influenza antigenic cartography.

    PubMed

    Cai, Zhipeng; Zhang, Tong; Wan, Xiu-Feng

    2010-10-07

    Influenza viruses have been responsible for large losses of lives around the world and continue to present a great public health challenge. Antigenic characterization based on hemagglutination inhibition (HI) assay is one of the routine procedures for influenza vaccine strain selection. However, HI assay is only a crude experiment reflecting the antigenic correlations among testing antigens (viruses) and reference antisera (antibodies). Moreover, antigenic characterization is usually based on more than one HI dataset. The combination of multiple datasets results in an incomplete HI matrix with many unobserved entries. This paper proposes a new computational framework for constructing an influenza antigenic cartography from this incomplete matrix, which we refer to as Matrix Completion-Multidimensional Scaling (MC-MDS). In this approach, we first reconstruct the HI matrices with viruses and antibodies using low-rank matrix completion, and then generate the two-dimensional antigenic cartography using multidimensional scaling. Moreover, for influenza HI tables with herd immunity effect (such as those from Human influenza viruses), we propose a temporal model to reduce the inherent temporal bias of HI tables caused by herd immunity. By applying our method in HI datasets containing H3N2 influenza A viruses isolated from 1968 to 2003, we identified eleven clusters of antigenic variants, representing all major antigenic drift events in these 36 years. Our results showed that both the completed HI matrix and the antigenic cartography obtained via MC-MDS are useful in identifying influenza antigenic variants and thus can be used to facilitate influenza vaccine strain selection. The webserver is available at http://sysbio.cvm.msstate.edu/AntigenMap.

  18. Phase retrieval for optical metrology

    NASA Astrophysics Data System (ADS)

    Pedrini, Giancarlo; Faridian, Ahmad; Singh, Alok Kumar; Osten, Wolfgang

    2014-11-01

    Phase retrieval methods have useful applications for optical imaging, metrology and 3D reconstruction. One such technique to recover the phase of the object wavefront is digital holography. In this paper we will show applications of digital holographic techniques for the time resolved measurement of deformation of microelectromechanical systems (MEMS) and for determination of residual stresses. Furthermore digital holography can be used for the investigations of microscopic samples and its resolution can be increased by using short wavelength and oblique illumination. We will see as well that dark-field digital holographic microscopy can be used to visualize biological specimens. A phase retrieval methods, which does not use a reference wave is also described in the last part of the paper.

  19. Retrieval options study

    SciTech Connect

    Not Available

    1980-03-01

    This Retrieval Options Study is part of the systems analysis activities of the Office of Nuclear Waste Isolation to develop the scientific and technological bases for radioactive waste repositories in various geologic media. The study considers two waste forms, high level waste and spent fuel, and defines various classes of waste retrieval and recovery. A methodology and data base are developed which allow the relative evaluation of retrieval and recovery costs and the following technical criteria: safety; technical feasibility; ease of retrieval; probable intact retrieval time; safeguards; monitoring; criticality; and licensability. A total of 505 repository options are defined and the cost and technical criteria evaluated utilizing a combination of facts and engineering judgments. The repositories evaluated are selected combinations of the following parameters: Geologic Media (salt, granite, basalt, shale); Retrieval Time after Emplacement (5 and 25 years); Emplacement Design (nominal hole, large hole, carbon steel canister, corrosion resistant canister, backfill in hole, nominal sleeves, thick wall sleeves); Emplacement Configuration (single vertical, multiple vertical, single horizontal, multiple horizontal, vaults; Thermal Considerations; (normal design, reduced density, once-through ventilation, recirculated ventilation); Room Backfill; (none, run-of-mine, early, 5 year delay, 25 year delay, decommissioned); and Rate of Retrieval; (same as emplacement, variably slower depending on repository/canister condition).

  20. TOFIR: A Tool of Facilitating Information Retrieval - Introduce a Visual Retrieval Model.

    ERIC Educational Resources Information Center

    Zhang, Jin

    2001-01-01

    Introduces a new method for the visualization of information retrieval called TOFIR (Tool of Facilitating Information Retrieval). Discusses the use of angle attributes of a document to construct the angle-based visual space; two-dimensional and three-dimensional visual tools; ambiguity; and future research directions. (Author/LRW)

  1. An integrated content and metadata based retrieval system for art.

    PubMed

    Lewis, Paul H; Martinez, Kirk; Abas, Fazly Salleh; Fauzi, Mohammad Faizal Ahmad; Chan, Stephen C Y; Addis, Matthew J; Boniface, Mike J; Grimwood, Paul; Stevenson, Alison; Lahanier, Christian; Stevenson, James

    2004-03-01

    A new approach to image retrieval is presented in the domain of museum and gallery image collections. Specialist algorithms, developed to address specific retrieval tasks, are combined with more conventional content and metadata retrieval approaches, and implemented within a distributed architecture to provide cross-collection searching and navigation in a seamless way. External systems can access the different collections using interoperability protocols and open standards, which were extended to accommodate content based as well as text based retrieval paradigms. After a brief overview of the complete system, we describe the novel design and evaluation of some of the specialist image analysis algorithms including a method for image retrieval based on sub-image queries, retrievals based on very low quality images and retrieval using canvas crack patterns. We show how effective retrieval results can be achieved by real end-users consisting of major museums and galleries, accessing the distributed but integrated digital collections.

  2. Quantitative evaluation of a single-distance phase-retrieval method applied on in-line phase-contrast images of a mouse lung

    PubMed Central

    Mohammadi, Sara; Larsson, Emanuel; Alves, Frauke; Dal Monego, Simeone; Biffi, Stefania; Garrovo, Chiara; Lorenzon, Andrea; Tromba, Giuliana; Dullin, Christian

    2014-01-01

    Propagation-based X-ray phase-contrast computed tomography (PBI) has already proven its potential in a great variety of soft-tissue-related applications including lung imaging. However, the strong edge enhancement, caused by the phase effects, often hampers image segmentation and therefore the quantitative analysis of data sets. Here, the benefits of applying single-distance phase retrieval prior to the three-dimensional reconstruction (PhR) are discussed and quantified compared with three-dimensional reconstructions of conventional PBI data sets in terms of contrast-to-noise ratio (CNR) and preservation of image features. The PhR data sets show more than a tenfold higher CNR and only minor blurring of the edges when compared with PBI in a predominately absorption-based set-up. Accordingly, phase retrieval increases the sensitivity and provides more functionality in computed tomography imaging. PMID:24971975

  3. Exploiting salient semantic analysis for information retrieval

    NASA Astrophysics Data System (ADS)

    Luo, Jing; Meng, Bo; Quan, Changqin; Tu, Xinhui

    2016-11-01

    Recently, many Wikipedia-based methods have been proposed to improve the performance of different natural language processing (NLP) tasks, such as semantic relatedness computation, text classification and information retrieval. Among these methods, salient semantic analysis (SSA) has been proven to be an effective way to generate conceptual representation for words or documents. However, its feasibility and effectiveness in information retrieval is mostly unknown. In this paper, we study how to efficiently use SSA to improve the information retrieval performance, and propose a SSA-based retrieval method under the language model framework. First, SSA model is adopted to build conceptual representations for documents and queries. Then, these conceptual representations and the bag-of-words (BOW) representations can be used in combination to estimate the language models of queries and documents. The proposed method is evaluated on several standard text retrieval conference (TREC) collections. Experiment results on standard TREC collections show the proposed models consistently outperform the existing Wikipedia-based retrieval methods.

  4. Gunther Tulip Retrievable Inferior Vena Caval Filters: Indications, Efficacy, Retrieval, and Complications

    SciTech Connect

    Looby, S.; Given, M.F.; Geoghegan, T.; McErlean, A.; Lee, M.J.

    2007-02-15

    Purpose. We evaluated the Gunther Tulip (GT) retrievable inferior vena cava (IVC) filter with regard to indications, filtration efficacy, complications, retrieval window, and use of anticoagulation. Method. A retrospective study was performed of 147 patients (64 men, 83 women; mean age 58.8 years) who underwent retrievable GT filter insertion between 2001 and 2005. The indications for placement included a diagnosis of pulmonary embolism or deep venous thrombosis with a contraindication to anticoagulation (n = 68), pulmonary embolism or deep venous thrombosis while on anticoagulation (n = 49), prophylactic filter placement for high-risk surgical patients with a past history of pulmonary embolism or deep venous thrombosis (n = 20), and a high risk of pulmonary embolism or deep venous thrombosis (n = 10). Forty-nine of the 147 patients did not receive anticoagulation (33.7%) while 96 of 147 patients did, 82 of these receiving warfarin (56.5%), 11 receiving low-molecular weight heparins (7.58%), and 3 receiving antiplatelet agents alone (2.06%). Results. Filter placement was successful in 147 patients (100%). Two patients had two filters inserted. Of the 147 patients, filter deployment was on a permanent basis in 102 and with an intention to retrieve in 45 patients. There were 36 (80%) successful retrievals and 9 (20%) failed retrievals. The mean time to retrieval was 33.6 days. The reasons for failed retrieval included filter struts tightly adherent to the IVC wall (5/9), extreme filter tilt (2/9), and extensive filter thrombus (2/9). Complications included pneumothorax (n = 4), failure of filter expansion (n = 1), and breakthrough pulmonary embolism (n = 1). No IVC thrombotic episodes were recorded. Discussion. The Gunther Tulip retrievable filter can be used as a permanent or a retrievable filter. It is safe and efficacious. GT filters can be safely retrieved at a mean time interval of 33.6 days. The newly developed Celect filter may extend the retrieval interval.

  5. Sensitivity Analysis for Atmospheric Infrared Sounder (AIRS) CO2 Retrieval

    NASA Technical Reports Server (NTRS)

    Gat, Ilana

    2012-01-01

    The Atmospheric Infrared Sounder (AIRS) is a thermal infrared sensor able to retrieve the daily atmospheric state globally for clear as well as partially cloudy field-of-views. The AIRS spectrometer has 2378 channels sensing from 15.4 micrometers to 3.7 micrometers, of which a small subset in the 15 micrometers region has been selected, to date, for CO2 retrieval. To improve upon the current retrieval method, we extended the retrieval calculations to include a prior estimate component and developed a channel ranking system to optimize the channels and number of channels used. The channel ranking system uses a mathematical formalism to rapidly process and assess the retrieval potential of large numbers of channels. Implementing this system, we identifed a larger optimized subset of AIRS channels that can decrease retrieval errors and minimize the overall sensitivity to other iridescent contributors, such as water vapor, ozone, and atmospheric temperature. This methodology selects channels globally by accounting for the latitudinal, longitudinal, and seasonal dependencies of the subset. The new methodology increases accuracy in AIRS CO2 as well as other retrievals and enables the extension of retrieved CO2 vertical profiles to altitudes ranging from the lower troposphere to upper stratosphere. The extended retrieval method for CO2 vertical profile estimation using a maximum-likelihood estimation method. We use model data to demonstrate the beneficial impact of the extended retrieval method using the new channel ranking system on CO2 retrieval.

  6. Retrieving Patent Information Online

    ERIC Educational Resources Information Center

    Kaback, Stuart M.

    1978-01-01

    This paper discusses patent information retrieval from online files in terms of types of questions, file contents, coverage, timeliness, and other file variations. CLAIMS, Derwent, WPI, APIPAT and Chemical Abstracts Service are described. (KP)

  7. Information retrieval system

    NASA Technical Reports Server (NTRS)

    Berg, R. F.; Holcomb, J. E.; Kelroy, E. A.; Levine, D. A.; Mee, C., III

    1970-01-01

    Generalized information storage and retrieval system capable of generating and maintaining a file, gathering statistics, sorting output, and generating final reports for output is reviewed. File generation and file maintenance programs written for the system are general purpose routines.

  8. Brewer Umkehr ozone profile retrievals

    NASA Astrophysics Data System (ADS)

    Petropavlovskikh, I. V.; Disterhoft, P.; Lantz, K. O.; Bhartia, P. K.; McPeters, R. D.; Flynn, L. E.; Oltmans, S. J.; Johnson, B. J.; Stanek, M.

    2011-12-01

    The Dobson Umkehr network has been a key data set for stratospheric ozone trend calculations (WMO Ozone assessments) and has earned its place as a benchmark network for stratospheric ozone profile observations. The Umkehr data has also been used to provide a long-term reference to the merging of the satellite ozone records (MOD), estimate the seasonal influence of an 11-year solar signal in the vertical distribution of stratospheric ozone, and to assess the ability of several remote and in-situ sensing systems in capturing ozone variability. It was found that Dobson Umkehr measurement errors were often comparable to errors derived for satellite and ozone-sounding methods. The Umkehr measurements are also available from the Brewer spectrophotometers [McElroy et al., 1995]. In 2005, the Dobson Umkehr algorithm (UMK04) was modified to retrieve ozone profile data from Brewer Umkehr measurements taken at two spectral channels [Petropavlovskikh et al, 2011]. The PC version of the Brewer algorithm was developed by M. Stanek (IOC, Canada and Czech Republic Meteorological Institute) in close collaboration with I. Petropavlovskikh. It was implemented at the NEUBrew network for operational processing of Umkehr data retrieved daily for all operational sites. The most recently developed Brewer ozone retrieval algorithm (MSBU) utilizes measurements that are currently available from the operational Brewer instruments. Umkehr measurements at multiple wavelength channels (similar to the satellite BUV method) and significantly reduced range of solar zenith angle are used for the twice a day operational ozone profile retrievals. Intercomparisons against ozone climatology, sounding, satellite overpasses and Dobson ozone datasets for NOASA/Goddard, Boulder, CO and MLO, HI sites are presented in this paper. The MSBU algorithm reduces noise in the intra-annual variability of the Brewer retrieved ozone as compared to the single pair ozone retrieval. Tropospheric ozone retrievals also

  9. Online medication history retrieval.

    PubMed

    Herdman, Bruce W; Varghese, Sandy R; Domer-Shank, Reed Bosch

    2015-01-01

    The difficulty of obtaining accurate medication history from inmates at the time of incarceration is daunting. This article summarizes the success of a large urban jail in the use of online data to identify medication history upon incarceration. This article describes the scope of available prescription data, the implementation of online retrieval, system limitations, planned improvements, and suggestions of additional applications of online retrieval services.

  10. Transcutaneous antigen delivery system

    PubMed Central

    Lee, Mi-Young; Shin, Meong-Cheol; Yang, Victor C.

    2013-01-01

    Transcutaneous immunization refers to the topical application of antigens onto the epidermis. Transcutaneous immunization targeting the Langerhans cells of the skin has received much attention due to its safe, needle-free, and noninvasive antigen delivery. The skin has important immunological functions with unique roles for antigen-presenting cells such as epidermal Langerhans cells and dermal dendritic cells. In recent years, novel vaccine delivery strategies have continually been developed; however, transcutaneous immunization has not yet been fully exploited due to the penetration barrier represented by the stratum corneum, which inhibits the transport of antigens and adjuvants. Herein we review recent achievements in transcutaneous immunization, focusing on the various strategies for the enhancement of antigen delivery and vaccination efficacy. [BMB Reports 2013; 46(1): 17-24] PMID:23351379

  11. Microscale purification of antigen-specific antibodies

    PubMed Central

    Brown, Eric P.; Normandin, Erica; Osei-Owusu, Nana Yaw; Mahan, Alison E.; Chan, Ying N.; Lai, Jennifer I.; Vaccari, Monica; Rao, Mangala; Franchini, Genoveffa; Alter, Galit; Ackerman, Margaret E.

    2015-01-01

    Glycosylation of the Fc domain is an important driver of antibody effector function. While assessment of antibody glycoform compositions observed across total plasma IgG has identified differences associated with a variety of clinical conditions, in many cases it is the glycosylation state of only antibodies against a specific antigen or set of antigens that may be of interest, for example, in defining the potential effector function of antibodies produced during disease or after vaccination. Historically, glycoprofiling such antigen-specific antibodies in clinical samples has been challenging due to their low prevalence, the high sample requirement for most methods of glycan determination, and the lack of high-throughput purification methods. New methods of glycoprofiling with lower sample requirements and higher throughput have motivated the development of microscale and automatable methods for purification of antigen-specific antibodies from polyclonal sources such as clinical serum samples. In this work, we present a robot-compatible 96-well plate-based method for purification of antigen-specific antibodies, suitable for such population level glycosylation screening. We demonstrate the utility of this method across multiple antibody sources, using both purified plasma IgG and plasma, and across multiple different antigen types, with enrichment factors greater than 1000-fold observed. Using an on-column IdeS protease treatment, we further describe staged release of Fc and Fab domains, allowing for glycoprofiling of each domain. PMID:26078040

  12. Microscale purification of antigen-specific antibodies.

    PubMed

    Brown, Eric P; Normandin, Erica; Osei-Owusu, Nana Yaw; Mahan, Alison E; Chan, Ying N; Lai, Jennifer I; Vaccari, Monica; Rao, Mangala; Franchini, Genoveffa; Alter, Galit; Ackerman, Margaret E

    2015-10-01

    Glycosylation of the Fc domain is an important driver of antibody effector function. While assessment of antibody glycoform compositions observed across total plasma IgG has identified differences associated with a variety of clinical conditions, in many cases it is the glycosylation state of only antibodies against a specific antigen or set of antigens that may be of interest, for example, in defining the potential effector function of antibodies produced during disease or after vaccination. Historically, glycoprofiling such antigen-specific antibodies in clinical samples has been challenging due to their low prevalence, the high sample requirement for most methods of glycan determination, and the lack of high-throughput purification methods. New methods of glycoprofiling with lower sample requirements and higher throughput have motivated the development of microscale and automatable methods for purification of antigen-specific antibodies from polyclonal sources such as clinical serum samples. In this work, we present a robot-compatible 96-well plate-based method for purification of antigen-specific antibodies, suitable for such population level glycosylation screening. We demonstrate the utility of this method across multiple antibody sources, using both purified plasma IgG and plasma, and across multiple different antigen types, with enrichment factors greater than 1000-fold observed. Using an on-column IdeS protease treatment, we further describe staged release of Fc and Fab domains, allowing for glycoprofiling of each domain.

  13. Semantic-based surveillance video retrieval.

    PubMed

    Hu, Weiming; Xie, Dan; Fu, Zhouyu; Zeng, Wenrong; Maybank, Steve

    2007-04-01

    Visual surveillance produces large amounts of video data. Effective indexing and retrieval from surveillance video databases are very important. Although there are many ways to represent the content of video clips in current video retrieval algorithms, there still exists a semantic gap between users and retrieval systems. Visual surveillance systems supply a platform for investigating semantic-based video retrieval. In this paper, a semantic-based video retrieval framework for visual surveillance is proposed. A cluster-based tracking algorithm is developed to acquire motion trajectories. The trajectories are then clustered hierarchically using the spatial and temporal information, to learn activity models. A hierarchical structure of semantic indexing and retrieval of object activities, where each individual activity automatically inherits all the semantic descriptions of the activity model to which it belongs, is proposed for accessing video clips and individual objects at the semantic level. The proposed retrieval framework supports various queries including queries by keywords, multiple object queries, and queries by sketch. For multiple object queries, succession and simultaneity restrictions, together with depth and breadth first orders, are considered. For sketch-based queries, a method for matching trajectories drawn by users to spatial trajectories is proposed. The effectiveness and efficiency of our framework are tested in a crowded traffic scene. PMID:17405446

  14. Retrieval of constituent mixing ratios from limb thermal emission spectra

    NASA Technical Reports Server (NTRS)

    Shaffer, William A.; Kunde, Virgil G.; Conrath, Barney J.

    1988-01-01

    An onion-peeling iterative, least-squares relaxation method to retrieve mixing ratio profiles from limb thermal emission spectra is presented. The method has been tested on synthetic data, containing various amounts of added random noise for O3, HNO3, and N2O. The retrieval method is used to obtain O3 and HNO3 mixing ratio profiles from high-resolution thermal emission spectra. Results of the retrievals compare favorably with those obtained previously.

  15. Retrieval of constituent mixing ratios from limb thermal emission spectra

    NASA Astrophysics Data System (ADS)

    Shaffer, William A.; Kunde, Virgil G.; Conrath, Barney J.

    1988-08-01

    An onion-peeling iterative, least-squares relaxation method to retrieve mixing ratio profiles from limb thermal emission spectra is presented. The method has been tested on synthetic data, containing various amounts of added random noise for O3, HNO3, and N2O. The retrieval method is used to obtain O3 and HNO3 mixing ratio profiles from high-resolution thermal emission spectra. Results of the retrievals compare favorably with those obtained previously.

  16. Practical problems in the posthumous retrieval of sperm.

    PubMed

    Jequier, Anne M; Zhang, Melissa

    2014-12-01

    This communication discusses the practical problems that arise during the collection and processing of sperm that have been retrieved posthumously. It is based on a small group, namely the last six men from whom we carried out posthumous retrieval. The reason for each retrieval, the method of that retrieval, the assessment of the sperm retrieved, the subsequent viability of the sperm and their storage method are discussed. The many ethical and legal problems that arise both before and after posthumous sperm retrieval are huge in their complexity. Therefore, they will not be discussed here and this communication will be limited to the practical aspects of posthumous sperm retrieval. The purpose of this communication is to make some suggestions that will facilitate such collections. The whole subject of posthumous sperm collection is gaining increasing clinical importance and has begun to interest the media as demonstrated by the recent national coverage in an Australian newspaper.

  17. A Bayesian approach to microwave precipitation profile retrieval

    NASA Technical Reports Server (NTRS)

    Evans, K. Franklin; Turk, Joseph; Wong, Takmeng; Stephens, Graeme L.

    1995-01-01

    A multichannel passive microwave precipitation retrieval algorithm is developed. Bayes theorem is used to combine statistical information from numerical cloud models with forward radiative transfer modeling. A multivariate lognormal prior probability distribution contains the covariance information about hydrometeor distribution that resolves the nonuniqueness inherent in the inversion process. Hydrometeor profiles are retrieved by maximizing the posterior probability density for each vector of observations. The hydrometeor profile retrieval method is tested with data from the Advanced Microwave Precipitation Radiometer (10, 19, 37, and 85 GHz) of convection over ocean and land in Florida. The CP-2 multiparameter radar data are used to verify the retrieved profiles. The results show that the method can retrieve approximate hydrometeor profiles, with larger errors over land than water. There is considerably greater accuracy in the retrieval of integrated hydrometeor contents than of profiles. Many of the retrieval errors are traced to problems with the cloud model microphysical information, and future improvements to the algorithm are suggested.

  18. Expression and Antigenic Evaluation of VacA Antigenic Fragment of Helicobacter Pylori

    PubMed Central

    Hasanzadeh, Leila; Ghaznavi-Rad, Ehsanollah; Soufian, Safieh; Farjadi, Vahideh; Abtahi, Hamid

    2013-01-01

    Objective(s) : Helicobacter pylori, a human specific gastric pathogen is a causative agent of chronic active gastritis. The vacuolating cytotoxin (VacA) is an effective virulence factor involved in gastric injury. The aim of this study was to construct a recombinant protein containing antigenic region of VacA gene and determine its antigenicity. Materials and Methods: The antigenic region of VacA gene was detected by bioinformatics methods. The polymerase chain reaction method was used to amplify a highly antigenic region of VacA gene from chromosomal DNA of H. pylori. The eluted product was cloned into the prokaryotic expression vector pET32a. The target protein was expressed in the Escherichia coli BL21 (DE3) pLysS. The bacteria including pET32a-VacA plasmids were induced by IPTG. The antigenicity was finally studied by western blotting using sera of 15 H. pylori infected patients after purification. Results: Enzyme digestion analysis, PCR and DNA sequencing results showed that the target gene was inserted correctly into the recombinant vector. The expressed protein was purified successfully via affinity chromatography. Data indicated that antigenic region of VacA protein from Helicobacter pylori was recognized by all 15 patient’s sera. Conclusion : Our data showed that antigenic region of VacA protein can be expressed by in E. co.li. This protein was recognized by sera patients suffering from H. pylori infection. the recombinant protein has similar epitopes and close antigenic properties to the natural form of this antigen. Recombinant antigenic region of VacA protein also seems to be a promising antigen for protective and serologic diagnosis . PMID:23997913

  19. Retrievals of atmospheric columnar carbon dioxide and methane from GOSAT observations with photon path-length probability density function (PPDF) method

    NASA Astrophysics Data System (ADS)

    Bril, A.; Oshchepkov, S.; Yokota, T.; Yoshida, Y.; Morino, I.; Uchino, O.; Belikov, D. A.; Maksyutov, S. S.

    2014-12-01

    We retrieved the column-averaged dry air mole fraction of atmospheric carbon dioxide (XCO2) and methane (XCH4) from the radiance spectra measured by Greenhouse gases Observing SATellite (GOSAT) for 48 months of the satellite operation from June 2009. Recent version of the Photon path-length Probability Density Function (PPDF)-based algorithm was used to estimate XCO2 and optical path modifications in terms of PPDF parameters. We also present results of numerical simulations for over-land observations and "sharp edge" tests for sun-glint mode to discuss the algorithm accuracy under conditions of strong optical path modification. For the methane abundance retrieved from 1.67-µm-absorption band we applied optical path correction based on PPDF parameters from 1.6-µm carbon dioxide (CO2) absorption band. Similarly to CO2-proxy technique, this correction assumes identical light path modifications in 1.67-µm and 1.6-µm bands. However, proxy approach needs pre-defined XCO2 values to compute XCH4, whilst the PPDF-based approach does not use prior assumptions on CO2 concentrations.Post-processing data correction for XCO2 and XCH4 over land observations was performed using regression matrix based on multivariate analysis of variance (MANOVA). The MANOVA statistics was applied to the GOSAT retrievals using reference collocated measurements of Total Carbon Column Observing Network (TCCON). The regression matrix was constructed using the parameters that were found to correlate with GOSAT-TCCON discrepancies: PPDF parameters α and ρ, that are mainly responsible for shortening and lengthening of the optical path due to atmospheric light scattering; solar and satellite zenith angles; surface pressure; surface albedo in three GOSAT short wave infrared (SWIR) bands. Application of the post-correction generally improves statistical characteristics of the GOSAT-TCCON correlation diagrams for individual stations as well as for aggregated data.In addition to the analysis of the

  20. Memory Retrieval in Mice and Men.

    PubMed

    Ben-Yakov, Aya; Dudai, Yadin; Mayford, Mark R

    2015-10-05

    Retrieval, the use of learned information, was until recently mostly terra incognita in the neurobiology of memory, owing to shortage of research methods with the spatiotemporal resolution required to identify and dissect fast reactivation or reconstruction of complex memories in the mammalian brain. The development of novel paradigms, model systems, and new tools in molecular genetics, electrophysiology, optogenetics, in situ microscopy, and functional imaging, have contributed markedly in recent years to our ability to investigate brain mechanisms of retrieval. We review selected developments in the study of explicit retrieval in the rodent and human brain. The picture that emerges is that retrieval involves coordinated fast interplay of sparse and distributed corticohippocampal and neocortical networks that may permit permutational binding of representational elements to yield specific representations. These representations are driven largely by the activity patterns shaped during encoding, but are malleable, subject to the influence of time and interaction of the existing memory with novel information.

  1. Mapping epitopes and antigenicity by site-directed masking

    NASA Astrophysics Data System (ADS)

    Paus, Didrik; Winter, Greg

    2006-06-01

    Here we describe a method for mapping the binding of antibodies to the surface of a folded antigen. We first created a panel of mutant antigens (-lactamase) in which single surface-exposed residues were mutated to cysteine. We then chemically tethered the cysteine residues to a solid phase, thereby masking a surface patch centered on each cysteine residue and blocking the binding of antibodies to this region of the surface. By these means we mapped the epitopes of several mAbs directed to -lactamase. Furthermore, by depleting samples of polyclonal antisera to the masked antigens and measuring the binding of each depleted sample of antisera to unmasked antigen, we mapped the antigenicity of 23 different epitopes. After immunization of mice and rabbits with -lactamase in Freund's adjuvant, we found that the antisera reacted with both native and denatured antigen and that the antibody response was mainly directed to an exposed and flexible loop region of the native antigen. By contrast, after immunization in PBS, we found that the antisera reacted only weakly with denatured antigen and that the antibody response was more evenly distributed over the antigenic surface. We suggest that denatured antigen (created during emulsification in Freund's adjuvant) elicits antibodies that bind mainly to the flexible regions of the native protein and that this explains the correlation between antigenicity and backbone flexibility. Denaturation of antigen during vaccination or natural infections would therefore be expected to focus the antibody response to the flexible loops. backbone flexibility | Freund's adjuvant | conformational epitope | antisera

  2. Human factors analysis and design methods for nuclear waste retrieval systems. Volume III. User's guide for the computerized event-tree analysis technique. [CETAT computer program

    SciTech Connect

    Casey, S.M.; Deretsky, Z.

    1980-08-01

    This document provides detailed instructions for using the Computerized Event-Tree Analysis Technique (CETAT), a program designed to assist a human factors analyst in predicting event probabilities in complex man-machine configurations found in waste retrieval systems. The instructions contained herein describe how to (a) identify the scope of a CETAT analysis, (b) develop operator performance data, (c) enter an event-tree structure, (d) modify a data base, and (e) analyze event paths and man-machine system configurations. Designed to serve as a tool for developing, organizing, and analyzing operator-initiated event probabilities, CETAT simplifies the tasks of the experienced systems analyst by organizing large amounts of data and performing cumbersome and time consuming arithmetic calculations. The principal uses of CETAT in the waste retrieval development project will be to develop models of system reliability and evaluate alternative equipment designs and operator tasks. As with any automated technique, however, the value of the output will be a function of the knowledge and skill of the analyst using the program.

  3. New methods for the retrieval of chlorophyll red fluorescence from hyperspectral satellite instruments: simulations and application to GOME-2 and SCIAMACHY

    NASA Astrophysics Data System (ADS)

    Joiner, Joanna; Yoshida, Yasuko; Guanter, Luis; Middleton, Elizabeth M.

    2016-08-01

    Global satellite measurements of solar-induced fluorescence (SIF) from chlorophyll over land and ocean have proven useful for a number of different applications related to physiology, phenology, and productivity of plants and phytoplankton. Terrestrial chlorophyll fluorescence is emitted throughout the red and far-red spectrum, producing two broad peaks near 683 and 736 nm. From ocean surfaces, phytoplankton fluorescence emissions are entirely from the red region (683 nm peak). Studies using satellite-derived SIF over land have focused almost exclusively on measurements in the far red (wavelengths > 712 nm), since those are the most easily obtained with existing instrumentation. Here, we examine new ways to use existing hyperspectral satellite data sets to retrieve red SIF (wavelengths < 712 nm) over both land and ocean. Red SIF is thought to provide complementary information to that from the far red for terrestrial vegetation. The satellite instruments that we use were designed to make atmospheric trace-gas measurements and are therefore not optimal for observing SIF; they have coarse spatial resolution and only moderate spectral resolution (0.5 nm). Nevertheless, these instruments, the Global Ozone Monitoring Instrument 2 (GOME-2) and the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY), offer a unique opportunity to compare red and far-red terrestrial SIF at regional spatial scales. Terrestrial SIF has been estimated with ground-, aircraft-, or satellite-based instruments by measuring the filling-in of atmospheric and/or solar absorption spectral features by SIF. Our approach makes use of the oxygen (O2) γ band that is not affected by SIF. The SIF-free O2 γ band helps to estimate absorption within the spectrally variable O2 B band, which is filled in by red SIF. SIF also fills in the spectrally stable solar Fraunhofer lines (SFLs) at wavelengths both inside and just outside the O2 B band, which further helps to estimate red SIF

  4. Tresyl-based conjugation of protein antigen to lipid nanoparticles increases antigen immunogenicity.

    PubMed

    Jain, Anekant; Yan, Weili; Miller, Keith R; O'Carra, Ronan; Woodward, Jerold G; Mumper, Russell J

    2010-11-30

    The present studies were aimed at investigating the engineering of NPs with protein-conjugated-surfactant at their surface. In order to increase the immunogenicity of a protein antigen, Brij 78 was functionalized by tresyl chloride and then further reacted with the primary amine of the model proteins ovalbumin (OVA) or horseradish peroxide (HRP). The reaction yielded Brij 78-OVA and Brij 78-HRP conjugates which were then used directly to form NP-OVA or NP-HRP using a one-step warm oil-in-water microemulsion precursor method with emulsifying wax as the oil phase, and Brij 78 and the Brij 78-OVA or Brij 78-HRP conjugate as surfactants. Similarly, Brij 700 was conjugated to HIV p24 antigen to yield Brij 700-p24 conjugate. The utility of these NPs for enhancing the immune responses to protein-based vaccines was evaluated in vivo using ovalbumin (OVA) as model protein and p24 as a relevant HIV antigen. In separate in vivo studies, female BALB/c mice were immunized by subcutaneous (s.c.) injection with NP-OVA and NP-p24 formulations along with several control formulations. These results suggested that with multiple antigens, covalent attachment of the antigen to the NP significantly enhanced antigen-specific immune responses. This facile covalent conjugation and incorporation method may be utilized to further incorporate other protein antigens, even multiple antigens, into an enhanced vaccine delivery system. PMID:20837122

  5. Tresyl-Based Conjugation of Protein Antigen to Lipid Nanoparticles Increases Antigen Immunogencity

    PubMed Central

    Jain, Anekant; Yan, Weili; Miller, Keith R.; O'Carra, Ronan; Woodward, Jerold G.; Mumper, Russell J.

    2010-01-01

    The present studies were aimed at investigating the engineering of NPs with protein-conjugated-surfactant at their surface. In order to increase the immunogenicity of a protein antigen, Brij 78 was functionalized by tresyl chloride and then further reacted with the primary amine of the model proteins ovalbumin (OVA) or horseradish peroxide (HRP). The reaction yielded Brij 78-OVA and Brij 78-HRP conjugates which were then used directly to form NP-OVA or NP-HRP using a one-step warm oil-in-water microemulsion precursor method with emulsifying wax as the oil phase, and Brij 78 and the Brij 78-OVA or Brij 78-HRP conjugate as surfactants. Similarly, Brij 700 was conjugated to HIV p24 antigen to yield Brij 700-p24 conjugate. The utility of these NPs for enhancing the immune responses to protein-based vaccines was evaluated in vivo using ovalbumin (OVA) as model protein and p24 as a relevant HIV antigen. In separate in vivo studies, female BALB/c mice were immunized by subcutaneous (s.c.) injection with NP-OVA and NP-p24 formulations along with several control formulations. These results suggested that with multiple antigens, covalent attachment of the antigen to the NP significantly enhanced antigen-specific immune responses. This facile covalent conjugation and incorporation method may be utilized to further incorporate other protein antigens, even multiple antigens, into an enhanced vaccine delivery system. PMID:20837122

  6. Retrieval Studies with LIDORT

    NASA Technical Reports Server (NTRS)

    Bhartia, P. K. (Technical Monitor); Spurr, Robert J. D.; Chance, K. V.

    2003-01-01

    This short program of LIDORT-based research in atmospheric trace gas retrieval was conducted over the 1 year period 01 July 2002 to 30 June 2003. After consultation with the NASA reporting officer, the first of the two original proposal activities (development of a direct-fitting total O3 column retrieval algorithm with operational capability for GOME data) was replaced by other tasks. The three activities addressed were: (1) Sensitivity studies for column and profile retrieval of NO2 distributions from a new generation of multi-axis ground-based spectrometers; (2) use of the LIDORT-RRS model to determine the effect of inelastic rotational Raman scattering at SBUV wavelengths; (3) an examination of ozone profile weighting functions in the presence of optically thick tropospheric clouds.

  7. Impact of high-dose chemotherapy on antigen-specific T cell immunity in breast cancer patients. Application of new flow cytometric method.

    PubMed

    Svane, I M; Nikolajsen, K; Hansen, S W; Kamby, C; Nielsen, D L; Johnsen, H E

    2002-04-01

    The present study analyses the influence of high-dose chemotherapy (HD) and autologous stem cell transplantation on natural and vaccine-induced specific immunity in breast cancer patients. Peripheral blood was collected from five breast cancer patients at serial time points in connection with treatment and in a follow-up period of 1 year. The frequencies of CD8+ and CD4+ T cells responsive to cytomegalovirus (CMV), varicella zoster virus (VZV), and tetanus in antigen-activated whole blood were determined by flow cytometric analysis of CD69, TNF alpha, IFN gamma and IL-4 expression. Mononuclear cells were labelled with PKH26 dye and the CMV, VZV, and tetanus toxoid-specific proliferation of T cell subpopulations was analysed by flow cytometry. In none of the patients did the treatment result in loss of overall T cell reactivity for any of the antigens. Prior to chemotherapy 5/5 patients possessed TNF alpha expressing T cells specific for CMV, 4/5 for VZV, and 3/5 for tetanus. One year after stem cell transplantation all patients possessed TNF alpha expressing T cells specific for CMV, VZV and tetanus. The highest percentages of cytokine-responding T cells were seen after stimulation with CMV antigen. In general, the lowest reactivity (close to zero) was measured in G-CSF-mobilised blood at the time of leukapheresis. In spite of a continuously reduced CD4 to CD8 ratio after transplantation, recovery of CD4+ T cells usually occurred prior to CD8+ recovery and often to a higher level. The study demonstrates that natural as well as vaccine-induced specific immunity established prior to HD can be regained after stem cell transplantation. These data indicate that introduction of a preventive cancer vaccination in combination with intensive chemotherapy may be a realistic treatment option.

  8. Antigenic determinant of the Lancefield group H antigen of Streptococcus sanguis.

    PubMed Central

    Rosan, B; Argenbright, L

    1982-01-01

    Previous studies indicated that the teichoic acid isolated from strains of Streptococcus sanguis was group specific and defined the Lancefield group H streptococci. To determine the specific antigenic determinants, the antigen was extracted from a group H streptococcus (ATCC 903) by the phenol-water method and purified by column chromatography. The isolated antigen had a glycerol/phosphate/glucose molar ratio of 1:0.9:0.3; the lipid concentration was 7.6% of its dry weight. No nucleic acids were detected, and amino acids constituted approximately 2% of the dry weight. The minimum concentration of antigen required to sensitize erythrocytes for hemagglutination with a 1:1,000 dilution of either group H antiserum or antiteichoic acid serum was 0.02 microgram/ml. Hemagglutination inhibition studies suggested that the major antigenic determinant consisted of an alpha-glucose linked to the glycerol phosphate backbone. Images PMID:6185428

  9. Evaluation of Retrievability of the Gunther Tulip Vena Cava Filter

    SciTech Connect

    Yamagami, Takuji Kato, Takeharu; Hirota, Tatsuya; Yoshimatsu, Rika; Matsumoto, Tomohiro; Nishimura, Tsunehiko

    2007-04-15

    Purpose. To evaluate the feasibility and safety of withdrawal of a Gunther tulip retrievable vena cava filter (GTF). Methods. Between June 2001 and December 2005, at our institution 86 GTFs were implanted for temporary caval filtration in 59 patients (37 women, 22 men; mean age 59.3 years, range 18-87 years). For GTFs retrieved thereafter, we retrospectively reviewed the following parameters: rate of success in retrieval, degree of trapped thrombus in the filter, and complications during retrieval. Results. Worsening of or new development of pulmonary embolism after filter implantation did not occur in any patient. Of the 86 GTFs implanted, retrieval of 80 was attempted. Among those 80 filters, 77 (96%) were successfully retrieved (with the standard method, n = 72; with the modified method, n = 5) without any complication. The period of implantation of the retrieved filters was 13.4 {+-} 4.2 days. In the 5 filters that were filled to a height of {>=} 1/4 with trapped thrombus, retrieval was performed after attempts were made to decrease trapped thrombi. In addition, a temporary filter or another GTF was temporarily placed at the cephalad level of the GTF during this removal procedure. Conclusion. GTFs can be retrieved in the majority of cases. Even when encountering situations in which the filter could not be removed using the standard method, withdrawal was possible in a high frequency of cases through various trials using modified methods.

  10. Information Retrieval Techniques.

    ERIC Educational Resources Information Center

    Kantor, Paul B.

    1994-01-01

    Identifies current trends in the automation of indexing, of information retrieval, and of interaction between the system and the users. Topics discussed include location, navigation, and indexing; digital libraries; matching documents to queries; weight of concepts; query structure, including fuzzy sets; algorithms; stemming; clustering; users'…

  11. Online Information Retrieval Bibliography

    ERIC Educational Resources Information Center

    Hawkins, Donald T.

    1978-01-01

    This is the first update of the bibliography on online information retrieval that was published as a supplement to Vol. 1 of this journal. Entries are divided into seven sections; within each section, they are listed alphabetically by author. Permuted titled (KWIC) and author indexes are included. (Author/JPF)

  12. Music Information Retrieval.

    ERIC Educational Resources Information Center

    Downie, J. Stephen

    2003-01-01

    Identifies MIR (Music Information Retrieval) computer system problems, historic influences, current state-of-the-art, and future MIR solutions through an examination of the multidisciplinary approach to MIR. Highlights include pitch; temporal factors; harmonics; tone; editorial, textual, and bibliographic facets; multicultural factors; locating…

  13. Information Retrieval by Television.

    ERIC Educational Resources Information Center

    Billowes, C. A.

    1968-01-01

    Bell Canada, the Public School and Collegiate Institute Boards of Ottawa, and the Ontario Institute for Studies in Education are collaborating on an educational television project which will provide a retrieval system that can supply any given program at any time under the control of the classroom teacher. Four schools in Ottawa will participate…

  14. Collaborative Information Retrieval.

    ERIC Educational Resources Information Center

    Bruce, Harry; Fidel, Raya

    1999-01-01

    Researchers from the University of Washington, Microsoft Research, Boeing, and Risoe National Laboratory in Denmark have embarked on a project to explore the manifestations of Collaborative Information Retrieval (CIR) in work settings and to propose technological innovations and organizational changes that can support, facilitate, and improve CIR.…

  15. Feedback in Information Retrieval.

    ERIC Educational Resources Information Center

    Spink, Amanda; Losee, Robert M.

    1996-01-01

    As Information Retrieval (IR) has evolved, it has become a highly interactive process, rooted in cognitive and situational contexts. Consequently the traditional cybernetic-based IR model does not suffice for interactive IR or the human approach to IR. Reviews different views of feedback in IR and their relationship to cybernetic and social…

  16. Retrieving Product Documentation Online.

    ERIC Educational Resources Information Center

    Racine, Sam J.; Crandall, Irving B.

    2001-01-01

    Discusses demands users face when searching for information in online libraries of product documentation. Demonstrates how physical libraries provide a helpful metaphor for design. Offers heuristics and a conceptual prototype for facilitating electronic document retrieval. Argues that the search form itself should communicate the way materials are…

  17. Multimedia Document Retrieval.

    ERIC Educational Resources Information Center

    Ozkarahan, Esen

    1995-01-01

    This study develops an integrated conceptual representation scheme for multimedia documents that are viewed to comprise an object-oriented database; the necessary abstractions for the conceptual model and extensions to the relational model used as the search structure; a retrieval model that includes associative, semantic and media-specific…

  18. Compressed sensing for phase retrieval.

    PubMed

    Newton, Marcus C

    2012-05-01

    To date there are several iterative techniques that enjoy moderate success when reconstructing phase information, where only intensity measurements are made. There remains, however, a number of cases in which conventional approaches are unsuccessful. In the last decade, the theory of compressed sensing has emerged and provides a route to solving convex optimisation problems exactly via ℓ(1)-norm minimization. Here the application of compressed sensing to phase retrieval in a nonconvex setting is reported. An algorithm is presented that applies reweighted ℓ(1)-norm minimization to yield accurate reconstruction where conventional methods fail.

  19. Phase retrieval with prior information.

    PubMed

    Irwan, R; Lane, R G

    1998-09-01

    An algorithm for phase retrieval with Bayesian statistics is discussed. It is shown how the statistics of Kolmogorov turbulence can be used to compute the likelihood for a particular phase screen. This likelihood is then added to that of the observed data to produce a functional that is maximized directly by use of conjugate gradient maximization. It is shown that although this can significantly improve the quality of the phase estimate,the issue is complicated by local maxima introduced by the possibility of phase wrapping. The causes of the local maxima are analyzed, and a method that increases the likelihood of convergence to the global maximum is presented.

  20. Retrieving handwriting by combining word spotting and manifold ranking

    NASA Astrophysics Data System (ADS)

    Peña Saldarriaga, Sebastián; Morin, Emmanuel; Viard-Gaudin, Christian

    2012-01-01

    Online handwritten data, produced with Tablet PCs or digital pens, consists in a sequence of points (x, y). As the amount of data available in this form increases, algorithms for retrieval of online data are needed. Word spotting is a common approach used for the retrieval of handwriting. However, from an information retrieval (IR) perspective, word spotting is a primitive keyword based matching and retrieval strategy. We propose a framework for handwriting retrieval where an arbitrary word spotting method is used, and then a manifold ranking algorithm is applied on the initial retrieval scores. Experimental results on a database of more than 2,000 handwritten newswires show that our method can improve the performances of a state-of-the-art word spotting system by more than 10%.

  1. Iterative Algorithms for Ptychographic Phase Retrieval

    SciTech Connect

    Yang, Chao; Qian, Jianliang; Schirotzek, Andre; Maia, Filipe; Marchesini, Stefano

    2011-05-03

    Ptychography promises diffraction limited resolution without the need for high resolution lenses. To achieve high resolution one has to solve the phase problem for many partially overlapping frames. Here we review some of the existing methods for solving ptychographic phase retrieval problem from a numerical analysis point of view, and propose alternative methods based on numerical optimization.

  2. Improving Performance Support Systems through Information Retrieval Evaluation

    ERIC Educational Resources Information Center

    Schatz, Steven

    2006-01-01

    This study examines existent and new methods for evaluating the success of information retrieval systems. The theory underlying current methods is not robust enough to allow testing retrieval using different meta-tagging schema's. Traditional measures rely on judgments of whether a document is relevant to a particular question. A good system…

  3. Discriminating antigen and non-antigen using proteome dissimilarity: bacterial antigens

    PubMed Central

    Ramakrishnan, Kamna; Flower, Darren R

    2010-01-01

    It has been postulated that immunogenicity results from the overall dissimilarity of pathogenic proteins versus the host proteome. We have sought to use this concept to discriminate between antigens and non-antigens of bacterial origin. Sets of 100 known antigenic and nonantigenic peptide sequences from bacteria were compared to human and mouse proteomes. Both antigenic and non-antigenic sequences lacked human or mouse homologues. Observed distributions were compared using the non-parametric Mann-Whitney test. The statistical null hypothesis was accepted, indicating that antigen and non-antigens did not differ significantly. Likewise, we were unable to determine a threshold able to separate meaningfully antigen from non-antigen. Thus, antigens cannot be predicted from pathogen genomes based solely on their dissimilarity to the human genome. PMID:20975907

  4. Presentation of hepatocellular antigens

    PubMed Central

    Grakoui, Arash; Crispe, Ian Nicholas

    2016-01-01

    The liver is an organ in which antigen-specific T-cell responses manifest a bias toward immune tolerance. This is clearly seen in the rejection of allogeneic liver transplants, and multiple other phenomena suggest that this effect is more general. These include tolerance toward antigens introduced via the portal vein, immune failure to several hepatotropic viruses, the lack of natural liver-stage immunity to malaria parasites, and the frequent metastasis of cancers to the liver. Here we review the mechanisms by which T cells engage with hepatocellular antigens, the context in which such encounters occur, and the mechanisms that act to suppress a full T-cell response. While many mechanisms play a role, we will argue that two important processes are the constraints on the cross-presentation of hepatocellular antigens, and the induction of negative feedback inhibition driven by interferons. The constant exposure of the liver to microbial products from the intestine may drive innate immunity, rendering the local environment unfavorable for specific T-cell responses through this mechanism. Nevertheless, tolerance toward hepatocellular antigens is not monolithic and under specific circumstances allows both effective immunity and immunopathology. PMID:26924525

  5. Simulated Radiative Transfer DOAS - A new method for improving volcanic SO2 emissions retrievals from ground-based UV-spectroscopic measurements of scattered solar radiation

    NASA Astrophysics Data System (ADS)

    Kern, C.; Deutschmann, T.; Vogel, L.; Bobrowski, N.; Hoermann, C.; Werner, C. A.; Sutton, A. J.; Elias, T.

    2011-12-01

    Passive Differential Optical Absorption Spectroscopy (DOAS) has become a standard tool for measuring SO2 at volcanoes. More recently, ultra-violet (UV) cameras have also been applied to obtain 2D images of SO2-bearing plumes. Both techniques can be used to derive SO2 emission rates by measuring SO2 column densities, integrating these along the plume cross-section, and multiplying by the wind speed. Recent measurements and model studies have revealed that the dominating source of uncertainty in these techniques often originates from an inaccurate assessment of radiative transfer through the volcanic plume. The typical assumption that all detected radiation is scattered behind the volcanic plume and takes a straight path from there to the instrument is often incorrect. We recently showed that the straight path assumption can lead to column density errors of 50% or more in cases where plumes with high SO2 and aerosol concentrations are measured from several kilometers distance, or where the background atmosphere contains a large amount of scattering aerosols. Both under- and overestimation are possible depending on the atmospheric conditions and geometry during spectral acquisition. Simulated Radiative Transfer (SRT) DOAS is a new evaluation scheme that combines radiative transfer modeling with spectral analysis of passive DOAS measurements in the UV region to derive more accurate SO2 column densities than conventional DOAS retrievals, which in turn leads to considerably more accurate emission rates. A three-dimensional backward Monte Carlo radiative transfer model is used to simulate realistic light paths in and around the volcanic plume containing variable amounts of SO2 and aerosols. An inversion algorithm is then applied to derive the true SO2 column density. For fast processing of large datasets, a linearized algorithm based on lookup tables was developed and tested on a number of example datasets. In some cases, the information content of the spectral data is

  6. Identification and manipulation of antigen specific T-cells with artificial antigen presenting cells.

    PubMed

    Koffeman, Eva; Keogh, Elissa; Klein, Mark; Prakken, Berent; Albani, Salvatore

    2007-01-01

    T-cells specific for a particular antigen represent a small percentage of the overall T-cell population. Detecting the presence of antigen specific T-cells in patients, animal models or populations of cultured cells has presented a challenge to researchers. The T-cell capture method described here utilizes a truly artificial method of antigen presentation and requires only 50,000 cells for the detection of the major histomcompatibility complex (MHC) class II and antigen restricted T-cells. With this method, liposomes, prepared with readily available materials, are loaded with neutravidin "rafts" comprised of MHC/peptide complexes, anti-CD28, a costimulatory molecule, and anti-LFA-1, an adhesion molecule. These artificial APCs are easily manipulated to include any MHC, antibodies to cell surface markers and/or costimulatory signals of interest thereby enabling not only T-cell identification but also the manipulation of mechanisms of T-cell activation. PMID:17983141

  7. Pathways of Antigen Processing

    PubMed Central

    Blum, Janice S.; Wearsch, Pamela A.; Cresswell, Peter

    2014-01-01

    T cell recognition of antigen presenting cells depends on their expression of a spectrum of peptides bound to Major Histocompatibility Complex class I (MHC-I) and class II (MHC-II) molecules. Conversion of antigens from pathogens or transformed cells into MHC-I and MHC-II-bound peptides is critical for mounting protective T cell responses, and similar processing of self proteins is necessary to establish and maintain tolerance. Cells use a variety of mechanisms to acquire protein antigens, from translation in the cytosol to variations on the theme of endocytosis, and to degrade them once acquired. In this review we highlight the aspects of MHC-I and MHC-II biosynthesis and assembly that have evolved to intersect these pathways and sample the peptides that are produced. PMID:23298205

  8. Language Processing in Information Retrieval.

    ERIC Educational Resources Information Center

    Doszkocs, Tamase

    1986-01-01

    Examines role and contributions of natural-language processing in information retrieval and artificial intelligence research in context of large operational information retrieval systems and services. State-of-the-art information retrieval systems combining the functional capabilities of conventional inverted file term adjacency approach with…

  9. DORS: DDC Online Retrieval System.

    ERIC Educational Resources Information Center

    Liu, Songqiao; Svenonius, Elaine

    1991-01-01

    Describes the Dewey Online Retrieval System (DORS), which was developed at the University of California, Los Angeles (UCLA), to experiment with classification-based search strategies in online catalogs. Classification structures in automated information retrieval are discussed; and specifications for a classification retrieval interface are…

  10. A Visual Information Retrieval Tool.

    ERIC Educational Resources Information Center

    Zhang, Jin

    2000-01-01

    Discussion of visualization for information retrieval, that transforms unseen internal semantic representation of a document collection into visible geometric displays, focuses on DARE (Distance Angle Retrieval Environment). Highlights include expression of information need; interpretation and manipulation of information retrieval models; ranking…

  11. Sperm retrieval during critical illness.

    PubMed

    Powner, David J; Rumohr, Jon A; Lipshultz, Larry I

    2010-06-01

    Objective of this study is to review technical methods to retrieve sperm from critically ill/injured patients after an appropriate family request, possible harmful effects on sperm production/function by ICU medications or concurrent illnesses, and ethical considerations for hospitals and care providers in providing this resource. Design used for this study includes: literature review, PubMed 1998-2009, and authors' files. There are no interventions. In conclusion, although successful and unsuccessful pregnancies following sperm removal from critically-ill patients are reported, no firm probability predictions for either result are known. Acute and chronic diseases that effect the hypothalamic-pituitary-gonadal axis and multiple medications common to the ICU may reduce sperm production or function. Retrieval methods before and after cardio-respiratory death differ and often require intracytoplasmic sperm injection or other in vitro fertilization techniques to achieve a subsequent pregnancy. The proactive development of a collaborative policy/procedure to identify appropriate roles for the hospital, its employees, and affiliated critical care and urology physicians is strongly recommended.

  12. Nonstationary signal analysis in episodic memory retrieval

    NASA Astrophysics Data System (ADS)

    Ku, Y. G.; Kawasumi, Masashi; Saito, Masao

    2004-04-01

    The problem of blind source separation from a mixture that has nonstationarity can be seen in signal processing, speech processing, spectral analysis and so on. This study analyzed EEG signal during episodic memory retrieval using ICA and TVAR. This paper proposes a method which combines ICA and TVAR. The signal from the brain not only exhibits the nonstationary behavior, but also contain artifacts. EEG data at the frontal lobe (F3) from the scalp is collected during the episodic memory retrieval task. The method is applied to EEG data for analysis. The artifact (eye movement) is removed by ICA, and a single burst (around 6Hz) is obtained by TVAR, suggesting that the single burst is related to the brain activity during the episodic memory retrieval.

  13. Semantic-Aware Co-Indexing for Image Retrieval.

    PubMed

    Zhang, Shiliang; Yang, Ming; Wang, Xiaoyu; Lin, Yuanqing; Tian, Qi

    2015-12-01

    In content-based image retrieval, inverted indexes allow fast access to database images and summarize all knowledge about the database. Indexing multiple clues of image contents allows retrieval algorithms search for relevant images from different perspectives, which is appealing to deliver satisfactory user experiences. However, when incorporating diverse image features during online retrieval, it is challenging to ensure retrieval efficiency and scalability. In this paper, for large-scale image retrieval, we propose a semantic-aware co-indexing algorithm to jointly embed two strong cues into the inverted indexes: 1) local invariant features that are robust to delineate low-level image contents, and 2) semantic attributes from large-scale object recognition that may reveal image semantic meanings. Specifically, for an initial set of inverted indexes of local features, we utilize semantic attributes to filter out isolated images and insert semantically similar images to this initial set. Encoding these two distinct and complementary cues together effectively enhances the discriminative capability of inverted indexes. Such co-indexing operations are totally off-line and introduce small computation overhead to online retrieval, because only local features but no semantic attributes are employed for the query. Hence, this co-indexing is different from existing image retrieval methods fusing multiple features or retrieval results. Extensive experiments and comparisons with recent retrieval methods manifest the competitive performance of our method. PMID:26539859

  14. Semantic-Aware Co-Indexing for Image Retrieval.

    PubMed

    Zhang, Shiliang; Yang, Ming; Wang, Xiaoyu; Lin, Yuanqing; Tian, Qi

    2015-12-01

    In content-based image retrieval, inverted indexes allow fast access to database images and summarize all knowledge about the database. Indexing multiple clues of image contents allows retrieval algorithms search for relevant images from different perspectives, which is appealing to deliver satisfactory user experiences. However, when incorporating diverse image features during online retrieval, it is challenging to ensure retrieval efficiency and scalability. In this paper, for large-scale image retrieval, we propose a semantic-aware co-indexing algorithm to jointly embed two strong cues into the inverted indexes: 1) local invariant features that are robust to delineate low-level image contents, and 2) semantic attributes from large-scale object recognition that may reveal image semantic meanings. Specifically, for an initial set of inverted indexes of local features, we utilize semantic attributes to filter out isolated images and insert semantically similar images to this initial set. Encoding these two distinct and complementary cues together effectively enhances the discriminative capability of inverted indexes. Such co-indexing operations are totally off-line and introduce small computation overhead to online retrieval, because only local features but no semantic attributes are employed for the query. Hence, this co-indexing is different from existing image retrieval methods fusing multiple features or retrieval results. Extensive experiments and comparisons with recent retrieval methods manifest the competitive performance of our method.

  15. REMOTE RETRIEVING TOOL

    DOEpatents

    Fromm, L.W. Jr.

    1958-08-19

    A retrieving tool is described to securely grasp an object for emplacement in, or withdrawal from, an elongated tube. The object is grasped by hooks actuated by a wedge and cann mechanism. The mechanism on the end of a long rodlike structure is controlled by levers or bars at the access end of the tube. This device is particularly useful for positioning fuel elements within a reactor core.

  16. Magnetic junk retriever

    SciTech Connect

    Moseley, M.D.

    1980-10-07

    An improved magnetic junk retriever arranged to magnetize a drill bit just prior to its removal from the bottom of the well bore. A wound, electromagnet subassembly is connected between the drill bit and the drill collar. A battery-pack tool is used to energize the electromagnet by lowering the tool through the bore of the drill pipe and collars to contact pins projecting into the bore of the sub. Energizing the electromagnet causes the drill bit to be magnetized.

  17. A content-based news video retrieval system: NVRS

    NASA Astrophysics Data System (ADS)

    Liu, Huayong; He, Tingting

    2009-10-01

    This paper focus on TV news programs and design a content-based news video browsing and retrieval system, NVRS, which is convenient for users to fast browsing and retrieving news video by different categories such as political, finance, amusement, etc. Combining audiovisual features and caption text information, the system automatically segments a complete news program into separate news stories. NVRS supports keyword-based news story retrieval, category-based news story browsing and generates key-frame-based video abstract for each story. Experiments show that the method of story segmentation is effective and the retrieval is also efficient.

  18. Antigen detection systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Infectious agents or their constituent parts (antigens or nucleic acids) can be detected in fresh, frozen, or fixed tissues or other specimens, using a variety of direct or indirect assays. The assays can be modified to yield the greatest sensitivity and specificity but in most cases a particular m...

  19. Use of information-retrieval languages in automated retrieval of experimental data from long-term storage

    NASA Technical Reports Server (NTRS)

    Khovanskiy, Y. D.; Kremneva, N. I.

    1975-01-01

    Problems and methods are discussed of automating information retrieval operations in a data bank used for long term storage and retrieval of data from scientific experiments. Existing information retrieval languages are analyzed along with those being developed. The results of studies discussing the application of the descriptive 'Kristall' language used in the 'ASIOR' automated information retrieval system are presented. The development and use of a specialized language of the classification-descriptive type, using universal decimal classification indices as the main descriptors, is described.

  20. Surface UV retrieval from satellite data.

    PubMed

    Tikkanen, T

    2000-01-01

    Irradiance of biologically effective ultraviolet radiation on the Earth's surface is retrieved from satellite measurements using radiative transfer models. Retrieval methods are reviewed with a special emphasis on questions pertinent to the Arctic environment. In general, the main problem is the high variability of cloudiness. The most prominent features of high latitudes are the low Sun and the high UV reflectivity of snow-covered terrain. Being white like clouds, snow is a challenge for satellite imagery. The dependence of UV albedo on the properties of snow and ambient conditions is discussed. The use of auxiliary snow cover data from a meteorological model is planned.

  1. Loss of Retrieval Information in Prose Recall.

    ERIC Educational Resources Information Center

    Sehulster, Jerome R.; And Others

    The purpose of this research was to experimentally manipulate input and output orders of information and separate storage and retrieval components of prose free recall. The cued partial recall method, used in word list recall, was adapted to a prose learning task. Four short biographical stories of about 55 words each were systematically combined…

  2. Neural Systems behind Word and Concept Retrieval

    ERIC Educational Resources Information Center

    Damasio, H.; Tranel, D.; Grabowski, T.; Adolphs, R.; Damasio, A.

    2004-01-01

    Using both the lesion method and functional imaging (positron emission tomography) in large cohorts of subjects investigated with the same experimental tasks, we tested the following hypotheses: (A) that the retrieval of words which denote concrete entities belonging to distinct conceptual categories depends upon partially segregated regions in…

  3. Applications of Machine Learning in Information Retrieval.

    ERIC Educational Resources Information Center

    Cunningham, Sally Jo; Witten, Ian H.; Littin, James

    1999-01-01

    Introduces the basic ideas that underpin applications of machine learning to information retrieval. Describes applications of machine learning to text categorization. Considers how machine learning can be applied to the query-formulation process. Examines methods of document filtering, where the user specifies a query that is to be applied to an…

  4. Using Projects To Teach Information Retrieval.

    ERIC Educational Resources Information Center

    Pode, Adam

    2001-01-01

    Discusses the approach of using student projects to teach information retrieval. Examines projects completed by students at Mercyhurst College (Erie, Pennsylvania), and includes examples of their work. Discusses problems encountered, weaknesses exposed, and strengths of the project genre overall. Other issues raised include methods for reinforcing…

  5. A Context Vector Model for Information Retrieval.

    ERIC Educational Resources Information Center

    Billhardt, Holger; Borrajo, Daniel; Maojo, Victor

    2002-01-01

    Presents an indexing and information retrieval method that, based on the vector space model, incorporates term dependencies and thus obtains semantically richer representations of documents. Highlights include term context vectors; techniques for estimating the dependencies among terms; term weights; experimental results on four text collections;…

  6. Representation, indexing, and retrieval of moving objects

    NASA Astrophysics Data System (ADS)

    Ye, Huanzhuo; Gong, Jianya; Li, Deren; Pan, Jianping; Chen, Yumin

    2003-12-01

    Moving objects are complicated to manage because they involve temporal attributes as well as spatial attributes. There are two methods to represent the motion of moving objects, function method and sampling method. Motion state modeling, based on sampling method, can give object's position, orientation and their changes at a specific epoch, and encapsulates all the calculation by object orientation method. A big job is to search the motion state vectors efficiently, which can be performed with the help of 2n index trees. 2n index tree is an efficient index method to multi-dimensional data. Different kinds of motion data retrieval can be transformed to basic searching in 2n index trees. With proper operation algorithm, 2n index trees work well with the indexing and retrieval of moving objects.

  7. A Perspective on the Measurement of Retrieval Effectiveness.

    ERIC Educational Resources Information Center

    Cooper, William S.

    1978-01-01

    Uses an historical analogy with Archimedes' problem concerning the volume of his king's golden crown to illustrate the evaluation problem for document and reference retrieval systems. Various methods that have been developed since 1950 to measure retrieval effectiveness are described, and utility measure formulas are provided. (JD)

  8. The Creation of New Knowledge by Information Retrieval and Classification.

    ERIC Educational Resources Information Center

    Davies, Roy

    1989-01-01

    Reviews previous work on producing knowledge by the use of information retrieval or classification schemes, and describes techniques by which hidden knowledge may be retrieved, i.e., serendipity in browsing and use of appropriate search strategies. Possible future methods based on relational indexing or artificial intelligence are also explored.…

  9. Analysis of Search Failures in Document Retrieval Systems: A Review.

    ERIC Educational Resources Information Center

    Tonta, Yasar

    1992-01-01

    Discusses the concept of search failure in document retrieval systems and three effectiveness measures, precision, recall, and "fallout." Four research methods--retrieval effectiveness measures, user satisfaction measures, transaction log analysis, and critical incident technique--are examined, and findings of major studies using each of the…

  10. Inclusion of Strep-tag II in design of antigen receptors for T-cell immunotherapy.

    PubMed

    Liu, Lingfeng; Sommermeyer, Daniel; Cabanov, Alexandra; Kosasih, Paula; Hill, Tyler; Riddell, Stanley R

    2016-04-01

    Adoptive immunotherapy with genetically engineered T cells has the potential to treat cancer and other diseases. The introduction of Strep-tag II sequences into specific sites in synthetic chimeric antigen receptors or natural T-cell receptors of diverse specificities provides engineered T cells with a marker for identification and rapid purification, a method for tailoring spacer length of chimeric receptors for optimal function, and a functional element for selective antibody-coated, microbead-driven, large-scale expansion. These receptor designs facilitate cGMP manufacturing of pure populations of engineered T cells for adoptive T-cell therapies and enable in vivo tracking and retrieval of transferred cells for downstream research applications.

  11. Retrieving Atmospheric Profiles Data in the Presence of Clouds from Hyperspectral Remote Sensing Data

    NASA Technical Reports Server (NTRS)

    Liu, Xu; Larar, Allen M.; Zhou, Daniel K.; Kizer, Susan H.; Wu, Wan; Barnet, Christopher; Divakarla, Murty; Guo, Guang; Blackwell, Bill; Smith, William L.; Yang, Ping; Gu, Degui

    2011-01-01

    Different methods for retrieving atmospheric profiles in the presence of clouds from hyperspectral satellite remote sensing data will be described. We will present results from the JPSS cloud-clearing algorithm and NASA Langley cloud retrieval algorithm.

  12. System engineering approach to GPM retrieval algorithms

    SciTech Connect

    Rose, C. R.; Chandrasekar, V.

    2004-01-01

    System engineering principles and methods are very useful in large-scale complex systems for developing the engineering requirements from end-user needs. Integrating research into system engineering is a challenging task. The proposed Global Precipitation Mission (GPM) satellite will use a dual-wavelength precipitation radar to measure and map global precipitation with unprecedented accuracy, resolution and areal coverage. The satellite vehicle, precipitation radars, retrieval algorithms, and ground validation (GV) functions are all critical subsystems of the overall GPM system and each contributes to the success of the mission. Errors in the radar measurements and models can adversely affect the retrieved output values. Ground validation (GV) systems are intended to provide timely feedback to the satellite and retrieval algorithms based on measured data. These GV sites will consist of radars and DSD measurement systems and also have intrinsic constraints. One of the retrieval algorithms being studied for use with GPM is the dual-wavelength DSD algorithm that does not use the surface reference technique (SRT). The underlying microphysics of precipitation structures and drop-size distributions (DSDs) dictate the types of models and retrieval algorithms that can be used to estimate precipitation. Many types of dual-wavelength algorithms have been studied. Meneghini (2002) analyzed the performance of single-pass dual-wavelength surface-reference-technique (SRT) based algorithms. Mardiana (2003) demonstrated that a dual-wavelength retrieval algorithm could be successfully used without the use of the SRT. It uses an iterative approach based on measured reflectivities at both wavelengths and complex microphysical models to estimate both No and Do at each range bin. More recently, Liao (2004) proposed a solution to the Do ambiguity problem in rain within the dual-wavelength algorithm and showed a possible melting layer model based on stratified spheres. With the No and Do

  13. Compressive Shift Retrieval

    NASA Astrophysics Data System (ADS)

    Ohlsson, Henrik; Eldar, Yonina C.; Yang, Allen Y.; Sastry, S. Shankar

    2014-08-01

    The classical shift retrieval problem considers two signals in vector form that are related by a shift. The problem is of great importance in many applications and is typically solved by maximizing the cross-correlation between the two signals. Inspired by compressive sensing, in this paper, we seek to estimate the shift directly from compressed signals. We show that under certain conditions, the shift can be recovered using fewer samples and less computation compared to the classical setup. Of particular interest is shift estimation from Fourier coefficients. We show that under rather mild conditions only one Fourier coefficient suffices to recover the true shift.

  14. Music retrieval in ICOR

    NASA Astrophysics Data System (ADS)

    Finsterle, Lutz; Fischer, Stephan; Rimac, Ivica; Steinmetz, Ralf

    1999-08-01

    In this paper we describe music retrieval in ICOR, a project of Darmstadt TU. It is the goal of ICOR to find new interfaces to support applications of music video and music CDs. Although the project consists of audio and video analysis we concentrate on a description of the audio algorithms in this paper. We describe our MPEG-7 like data structure to store meta information for music pieces and explain which algorithms we use to analyze the content of music pieces automatically. We currently use an applause detection to distinguish live music from studio recordings, a genre classifier to distinguish pieces with beats form classical music, and a singer recognition.

  15. Echinococcus granulosus: specific quantification of the two most immunoreactive antigens in hydatid fluids

    PubMed Central

    Musiani, P.; Piantelli, M.; Lauriola, L.; Arru, E.; Pozzuoli, R.

    1978-01-01

    Preparations of the two most immunoreactive Echinococcus granulosus antigens (antigens 4 and 5) from sheep hydatid fluid, purified by a simplified method, and monospecific antisera against antigens 4 and 5, prepared by a new procedure, were used to measure the antigenic concentrations of antigens 4 and 5 in swine, sheep, and human hydatid fluids from pulmonary or hepatic cysts. Two bovine samples and two commercial preparations were also tested. The concentration of both antigens was significantly higher in sheep and human hydatid fluids than in swine hydatid fluid. The antigenic content of the two bovine samples and of the two commercial preparations was below the sensitivity level of the method employed. Independently of the species tested, the amount of Echinococcus antigens was greater in hepatic than in pulmonary cysts. The ratio between the concentrations of antigens 4 and 5 was constant at about 1:10 in the samples from various organs and from different species. When there were enough samples for statistical analysis a linear correlation was found between the contents of these two antigenic components but there was none between the amounts of proteins and the antigenic concentrations in the single cysts. Sheep hydatid fluid must therefore be considered the best source of antigenic material for diagnostic purposes even though in human cysts the antigenic fraction is less contaminated by serum proteins. We describe a reliable method of standardising antigenic material for the immunodiagnosis of hydatid disease. Imagesp476-a PMID:649773

  16. 2. VIEW OF INTERIOR OF XY RETRIEVER. THE XY RETRIEVER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. VIEW OF INTERIOR OF X-Y RETRIEVER. THE X-Y RETRIEVER WAS HOUSED IN MODULE K AND WAS USED TO SORT AND RETRIEVE PLUTONIUM METAL FROM A STORAGE VAULT FOR DISTRIBUTION TO OTHER PROCESSES IN BUILDING 707. (11/29/88) - Rocky Flats Plant, Plutonium Manufacturing Facility, North-central section of Plant, just south of Building 776/777, Golden, Jefferson County, CO

  17. Difficult OptEase Filter Retrievals After Prolonged Indwelling Times

    SciTech Connect

    Van Ha, Thuong G. Kang, Lisa; Lorenz, Jonathan; Zangan, Steven; Navuluri, Rakesh; Straus, Christopher; Funaki, Brian

    2013-08-01

    PurposeThe OptEase vena cave filter (Cordis, Piscataway, NJ) is commercially available as a retrievable or permanent filter with short recommended indwelling time, presumably due to extensive contact of the filter side struts with the inferior vena cava wall and subsequent neointimal hyperplasia leading to incorporation. Our purpose was to evaluate OptEase filter retrievals with a long indwelling time period that required unconventional retrieval techniques.Materials and MethodsWe retrospectively reviewed patients who underwent OptEase filter retrieval with long undwelling times requiring additional maneuvers for retrieval. Techniques used included rigid endobronchial forceps dissection and wire-through-loop snare. Each patient underwent postretrieval venogram to evaluate for possible complications. In addition, patients had clinical follow-up 2 weeks after the retrieval procedure.ResultsThere were three patients (2 women, 1 man; average age 64 years) who underwent OptEase filter retrieval. The mean indwelling time was 6.4 months. The indwelling filters were successfully retrieved. There were no complications. Postprocedural follow-up showed no clinical pathology.ConclusionUnconventional techniques aided in the retrieval of OptEase filters with long indwelling times.

  18. Cancer vaccine--Antigenics.

    PubMed

    2002-01-01

    Antigenics is developing a therapeutic cancer vaccine based on heat-shock proteins (HSPs). The vaccine [HSPPC-96, Oncophage] is in a pivotal phase III clinical trial for renal cancer at 80 clinical sites worldwide. The trial is enrolling at least 500 patients who are randomised to receive surgical removal of the primary tumour followed by out-patient treatment with Oncophage((R)) or surgery only. This study was initiated on the basis of results from a pilot phase I/II study and preliminary results from a phase II study in patients with renal cell cancer. In October 2001, Oncophage was designated as a fast-track product by the Food and Drug Administration in the US for the treatment of renal cell carcinoma. Oncophage is in phase I/II trials in Italy for colorectal cancer (30 patients) and melanoma. The trials in Italy are being conducted at the Istituto dei Tumouri, Milan (in association with Sigma-Tau). Preliminary data from the phase II trial for melanoma was presented at the AACR-NCI-EORTC International Conference in Florida, USA, in October 2001. Oncophage is also in a phase I/II (42 patients) and a phase II trial (84 patients) in the US for renal cell cancer, a phase II trial in the US for non-Hodgkin's lymphoma (35 patients), a phase II trial in the US for sarcoma (20-35 patients), a phase I/II trial in the US for melanoma (36 patients), and phase I/II trials in Germany for gastric (30 patients) and pancreatic cancers. A pilot phase I trial in patients with pancreatic cancer began in the US in 1997 with 5 patients enrolled. In November 2000, Antigenics announced that this trial had been expanded to a phase I/II study which would now include survival as an endpoint and would enroll 5 additional patients. The US trials are being performed at Memorial Sloan-Kettering Cancer Center and the M.D. Anderson Cancer Center. The trials in Germany are being carried out at Johannes Gutenberg-University Hospital, Mainz. Oncophage is an autologous vaccine consisting of

  19. Multiple image encryption by phase retrieval

    NASA Astrophysics Data System (ADS)

    Di, Hong; Kang, Yanmei; Liu, Yueqin; Zhang, Xin

    2016-07-01

    Multiple image encryption (MIE) was proposed to increase the efficiency of encrypting images by processing several images simultaneously. Because of the advantage of optical technology in processing twodimensional images at high throughput, MIE has been significantly improved by use of methods originating from optics. Phase retrieval was the process of algorithmically finding solutions to the phase loss problem due to light detectors only capturing the intensity. It was to retrieve phase information for the determination of a structure from diffraction data. Error-reduction algorithm is a typical phase retrieval method. Here, we employ it to illustrate that methods in phase retrieval are able to encrypt multiple images and compress them into encrypted data simultaneously. Moreover, the decryption is also designed to handle multiple images at the same time. The whole process including both the encryption and decryption is proposed to improve MIE with respect to the compression and efficiency. The feasibility and encryption of the MIE scheme is demonstrated with encryption experiments under Gaussian white noise and unauthorized access.

  20. 3D object retrieval using salient views

    PubMed Central

    Shapiro, Linda G.

    2013-01-01

    This paper presents a method for selecting salient 2D views to describe 3D objects for the purpose of retrieval. The views are obtained by first identifying salient points via a learning approach that uses shape characteristics of the 3D points (Atmosukarto and Shapiro in International workshop on structural, syntactic, and statistical pattern recognition, 2008; Atmosukarto and Shapiro in ACM multimedia information retrieval, 2008). The salient views are selected by choosing views with multiple salient points on the silhouette of the object. Silhouette-based similarity measures from Chen et al. (Comput Graph Forum 22(3):223–232, 2003) are then used to calculate the similarity between two 3D objects. Retrieval experiments were performed on three datasets: the Heads dataset, the SHREC2008 dataset, and the Princeton dataset. Experimental results show that the retrieval results using the salient views are comparable to the existing light field descriptor method (Chen et al. in Comput Graph Forum 22(3):223–232, 2003), and our method achieves a 15-fold speedup in the feature extraction computation time. PMID:23833704

  1. Memory engram storage and retrieval.

    PubMed

    Tonegawa, Susumu; Pignatelli, Michele; Roy, Dheeraj S; Ryan, Tomás J

    2015-12-01

    A great deal of experimental investment is directed towards questions regarding the mechanisms of memory storage. Such studies have traditionally been restricted to investigation of the anatomical structures, physiological processes, and molecular pathways necessary for the capacity of memory storage, and have avoided the question of how individual memories are stored in the brain. Memory engram technology allows the labeling and subsequent manipulation of components of specific memory engrams in particular brain regions, and it has been established that cell ensembles labeled by this method are both sufficient and necessary for memory recall. Recent research has employed this technology to probe fundamental questions of memory consolidation, differentiating between mechanisms of memory retrieval from the true neurobiology of memory storage.

  2. EM-21 Retrieval Knowledge Center: Waste Retrieval Challenges

    SciTech Connect

    Fellinger, Andrew P.; Rinker, Michael W.; Berglin, Eric J.; Minichan, Richard L.; Poirier, Micheal R.; Gauglitz, Phillip A.; Martin, Bruce A.; Hatchell, Brian K.; Saldivar, Eloy; Mullen, O Dennis; Chapman, Noel F.; Wells, Beric E.; Gibbons, Peter W.

    2009-04-10

    EM-21 is the Waste Processing Division of the Office of Engineering and Technology, within the U.S. Department of Energy’s (DOE) Office of Environmental Management (EM). In August of 2008, EM-21 began an initiative to develop a Retrieval Knowledge Center (RKC) to provide the DOE, high level waste retrieval operators, and technology developers with centralized and focused location to share knowledge and expertise that will be used to address retrieval challenges across the DOE complex. The RKC is also designed to facilitate information sharing across the DOE Waste Site Complex through workshops, and a searchable database of waste retrieval technology information. The database may be used to research effective technology approaches for specific retrieval tasks and to take advantage of the lessons learned from previous operations. It is also expected to be effective for remaining current with state-of-the-art of retrieval technologies and ongoing development within the DOE Complex. To encourage collaboration of DOE sites with waste retrieval issues, the RKC team is co-led by the Savannah River National Laboratory (SRNL) and the Pacific Northwest National Laboratory (PNNL). Two RKC workshops were held in the Fall of 2008. The purpose of these workshops was to define top level waste retrieval functional areas, exchange lessons learned, and develop a path forward to support a strategic business plan focused on technology needs for retrieval. The primary participants involved in these workshops included retrieval personnel and laboratory staff that are associated with Hanford and Savannah River Sites since the majority of remaining DOE waste tanks are located at these sites. This report summarizes and documents the results of the initial RKC workshops. Technology challenges identified from these workshops and presented here are expected to be a key component to defining future RKC-directed tasks designed to facilitate tank waste retrieval solutions.

  3. The potential of clear-sky carbon dioxide satellite retrievals

    NASA Astrophysics Data System (ADS)

    Nelson, Robert R.; O'Dell, Christopher W.; Taylor, Thomas E.; Mandrake, Lukas; Smyth, Mike

    2016-04-01

    ">2 root-mean-square errors (RMSEs) of less than 2.0 ppm, relative to Total Carbon Column Observing Network (TCCON) measurements and a suite of CO2 models, when adequately filtered through the use of a custom genetic algorithm filtering system. These results imply that non-scattering XCO2 retrievals are potentially more useful than previous literature suggests, as the filtering methods we employ are able to remove measurements in which scattering can cause significant errors. Additionally, the computational benefits of non-scattering retrievals means they may be useful for certain applications that require large amounts of data but have less stringent error requirements.

  4. The potential of clear-sky carbon dioxide satellite retrievals

    NASA Astrophysics Data System (ADS)

    Nelson, R. R.; O'Dell, C. W.; Taylor, T. E.; Mandrake, L.; Smyth, M.

    2015-12-01

    less than 2.0 ppm when adequately filtered through the use of the Data Ordering through Genetic Optimization (DOGO) system. These results imply that non-scattering XCO2 retrievals are potentially much more accurate than previous literature suggests, when employing filtering methods to remove measurements in which scattering can cause significant errors. Additionally, the computational benefits of non-scattering retrievals means they may be useful for certain applications that require large amounts of data but have less stringent error requirements.

  5. Care episode retrieval: distributional semantic models for information retrieval in the clinical domain

    PubMed Central

    2015-01-01

    Patients' health related information is stored in electronic health records (EHRs) by health service providers. These records include sequential documentation of care episodes in the form of clinical notes. EHRs are used throughout the health care sector by professionals, administrators and patients, primarily for clinical purposes, but also for secondary purposes such as decision support and research. The vast amounts of information in EHR systems complicate information management and increase the risk of information overload. Therefore, clinicians and researchers need new tools to manage the information stored in the EHRs. A common use case is, given a - possibly unfinished - care episode, to retrieve the most similar care episodes among the records. This paper presents several methods for information retrieval, focusing on care episode retrieval, based on textual similarity, where similarity is measured through domain-specific modelling of the distributional semantics of words. Models include variants of random indexing and the semantic neural network model word2vec. Two novel methods are introduced that utilize the ICD-10 codes attached to care episodes to better induce domain-specificity in the semantic model. We report on experimental evaluation of care episode retrieval that circumvents the lack of human judgements regarding episode relevance. Results suggest that several of the methods proposed outperform a state-of-the art search engine (Lucene) on the retrieval task. PMID:26099735

  6. Care episode retrieval: distributional semantic models for information retrieval in the clinical domain.

    PubMed

    Moen, Hans; Ginter, Filip; Marsi, Erwin; Peltonen, Laura-Maria; Salakoski, Tapio; Salanterä, Sanna

    2015-01-01

    Patients' health related information is stored in electronic health records (EHRs) by health service providers. These records include sequential documentation of care episodes in the form of clinical notes. EHRs are used throughout the health care sector by professionals, administrators and patients, primarily for clinical purposes, but also for secondary purposes such as decision support and research. The vast amounts of information in EHR systems complicate information management and increase the risk of information overload. Therefore, clinicians and researchers need new tools to manage the information stored in the EHRs. A common use case is, given a--possibly unfinished--care episode, to retrieve the most similar care episodes among the records. This paper presents several methods for information retrieval, focusing on care episode retrieval, based on textual similarity, where similarity is measured through domain-specific modelling of the distributional semantics of words. Models include variants of random indexing and the semantic neural network model word2vec. Two novel methods are introduced that utilize the ICD-10 codes attached to care episodes to better induce domain-specificity in the semantic model. We report on experimental evaluation of care episode retrieval that circumvents the lack of human judgements regarding episode relevance. Results suggest that several of the methods proposed outperform a state-of-the art search engine (Lucene) on the retrieval task.

  7. Semantic processing in information retrieval.

    PubMed Central

    Rindflesch, T. C.; Aronson, A. R.

    1993-01-01

    Intuition suggests that one way to enhance the information retrieval process would be the use of phrases to characterize the contents of text. A number of researchers, however, have noted that phrases alone do not improve retrieval effectiveness. In this paper we briefly review the use of phrases in information retrieval and then suggest extensions to this paradigm using semantic information. We claim that semantic processing, which can be viewed as expressing relations between the concepts represented by phrases, will in fact enhance retrieval effectiveness. The availability of the UMLS domain model, which we exploit extensively, significantly contributes to the feasibility of this processing. PMID:8130547

  8. [Presence of Australia antigen in blood donors].

    PubMed

    Gota, F

    1980-01-01

    The differential diagnosis of type A and B viral hepatitis is discussed and guidelines for the prevention of post-transfusional hospital hepatitis are proposed. Methods for the immunological demonstration of HBs antigen are illustrated, together with the respective positivity percentages in blood donors.

  9. Multilevel resistive information storage and retrieval

    DOEpatents

    Lohn, Andrew; Mickel, Patrick R.

    2016-08-09

    The present invention relates to resistive random-access memory (RRAM or ReRAM) systems, as well as methods of employing multiple state variables to form degenerate states in such memory systems. The methods herein allow for precise write and read steps to form multiple state variables, and these steps can be performed electrically. Such an approach allows for multilevel, high density memory systems with enhanced information storage capacity and simplified information retrieval.

  10. Tank Waste Retrieval Lessons Learned at the Hanford Site

    SciTech Connect

    Dodd, R.A.

    2008-07-01

    approval of an exception to the waste retrieval criteria for a specific tank. Tank waste retrieval has been conducted at the Hanford Site over the last few decades using a method referred to as Past Practice Hydraulic Sluicing. Past Practice Hydraulic Sluicing employs large volumes of DST supernatant and water to dislodge, dissolve, mobilize, and retrieve tank waste. Concern over the leak integrity of SSTs resulted in the need for tank waste retrieval methods capable of using smaller volumes of liquid in a more controlled manner. Retrieval of SST waste in accordance with HFFACO requirements was initiated at the Hanford Site in April 2003. New and innovative tank waste retrieval methods that minimize and control the use of liquids are being implemented for the first time. These tank waste retrieval methods replace Past Practice Hydraulic Sluicing and employ modified sluicing, vacuum retrieval, and in-tank vehicle techniques. Waste retrieval has been completed in seven Hanford Site SSTs (C-106, C-103, C-201, C-202, C-203, C-204, and S-112) in accordance with HFFACO requirements. Three additional tanks are currently in the process of being retrieved (C-108, C-109 and S-102) Preparation for retrieval of two additional SSTs (C-104 and C-110) is ongoing with retrieval operations forecasted to start in calendar year 2008. Tank C-106 was retrieved to a residual waste volume of 470 ft{sup 3} using oxalic acid dissolution and modified sluicing. An Appendix H exception request for Tank C-106 is undergoing review. Tank C-103 was retrieved to a residual volume of 351 ft{sup 3} using a modified sluicing technology. This approach was successful at reaching the TPA limits for this tank of less than 360 ft{sup 3}and the limits of the technology. Tanks C-201, C-202, C-203, and C-204 are smaller (55,000 gallon) tanks and waste removal was completed in accordance with HFFACO requirements using a vacuum retrieval system. Residual waste volumes in each of these four tanks were less than 25 ft

  11. A neural network-based method for merging ocean color and Argo data to extend surface bio-optical properties to depth: Retrieval of the particulate backscattering coefficient

    NASA Astrophysics Data System (ADS)

    Sauzède, R.; Claustre, H.; Uitz, J.; Jamet, C.; Dall'Olmo, G.; D'Ortenzio, F.; Gentili, B.; Poteau, A.; Schmechtig, C.

    2016-04-01

    The present study proposes a novel method that merges satellite ocean color bio-optical products with Argo temperature-salinity profiles to infer the vertical distribution of the particulate backscattering coefficient (bbp). This neural network-based method (SOCA-BBP for Satellite Ocean-Color merged with Argo data to infer the vertical distribution of the Particulate Backscattering coefficient) uses three main input components: (1) satellite-based surface estimates of bbp and chlorophyll a concentration matched up in space and time with (2) depth-resolved physical properties derived from temperature-salinity profiles measured by Argo profiling floats and (3) the day of the year of the considered satellite-Argo matchup. The neural network is trained and validated using a database including 4725 simultaneous profiles of temperature-salinity and bio-optical properties collected by Bio-Argo floats, with concomitant satellite-derived products. The Bio-Argo profiles are representative of the global open-ocean in terms of oceanographic conditions, making the proposed method applicable to most open-ocean environments. SOCA-BBP is validated using 20% of the entire database (global error of 21%). We present additional validation results based on two other independent data sets acquired (1) by four Bio-Argo floats deployed in major oceanic basins, not represented in the database used to train the method; and (2) during an AMT (Atlantic Meridional Transect) field cruise in 2009. These validation tests based on two fully independent data sets indicate the robustness of the predicted vertical distribution of bbp. To illustrate the potential of the method, we merged monthly climatological Argo profiles with ocean color products to produce a depth-resolved climatology of bbp for the global ocean.

  12. Monte Carlo Approach To Gomos Ozone Retrieval

    NASA Astrophysics Data System (ADS)

    Tamminen, J.; Kyrölä, E.

    Satellite measurements of the atmosphere are non-direct and therefore the data pro- cessing requires inverse methods. In this paper we apply the Bayesian approach and use the Markov chain Monte Carlo (MCMC) method for solving the retrieval problem of GOMOS mesurements. With the MCMC method we are able to compute the true nonlinear posterior distribution of the solution without linearizing the problem. The MCMC technique can easily be implemented in a great variety of retrieval prob- lems including nonlinear problems with various prior or noise structures. Therefore, MCMC methods, though somewhat slow for operational processing of large amounts of data, provide excellent tools for development and validation purposes. Moreover, when the signal-to-noise ratio is poor the MCMC methods can be used to find even the faintest fingerprints of the absorbers in the signal. The MCMC methods, and especially the reversible jump MCMC can also be used in problems where the dimension of the model space is unknown. We will discuss the possibility of using MCMC approach also in a model selection problem, namely, for choosing the model for the wavelength dependence of the aerosol cross sections and studying the optimal constituent set to be retrieved.

  13. Assessment of Snared-Loop Technique When Standard Retrieval of Inferior Vena Cava Filters Fails

    SciTech Connect

    Doody, Orla Noe, Geertje; Given, Mark F.; Foley, Peter T.; Lyon, Stuart M.

    2009-01-15

    Purpose To identify the success and complications related to a variant technique used to retrieve inferior vena cava filters when simple snare approach has failed. Methods A retrospective review of all Cook Guenther Tulip filters and Cook Celect filters retrieved between July 2006 and February 2008 was performed. During this period, 130 filter retrievals were attempted. In 33 cases, the standard retrieval technique failed. Retrieval was subsequently attempted with our modified retrieval technique. Results The retrieval was successful in 23 cases (mean dwell time, 171.84 days; range, 5-505 days) and unsuccessful in 10 cases (mean dwell time, 162.2 days; range, 94-360 days). Our filter retrievability rates increased from 74.6% with the standard retrieval method to 92.3% when the snared-loop technique was used. Unsuccessful retrieval was due to significant endothelialization (n = 9) and caval penetration by the filter (n = 1). A single complication occurred in the group, in a patient developing pulmonary emboli after attempted retrieval. Conclusion The technique we describe increased the retrievability of the two filters studied. Hook endothelialization is the main factor resulting in failed retrieval and continues to be a limitation with these filters.

  14. Retrieval of spatial field of atmospheric aerosol concentration according to data from local measurements: A modification of the method of back trajectory statistics

    NASA Astrophysics Data System (ADS)

    Poddubny, V. A.; Nagovitsyna, E. S.

    2013-07-01

    The well-known method of the back trajectory statistics (BTS) is used to develop a new approach to estimating atmospheric pollution fields according to local measurements. On the basis of instrumental measurements at one or a few monitoring points and information on atmospheric dynamics (in this work, back trajectories of the motion of air particles), the BTS method makes it possible to estimate the spatial structure of fields of a measured quantity. Results from solving a simplified demonstration of estimating the spatial distribution of the volume concentration of a fine aerosol fraction are presented; these results were obtained on the basis of an analysis of photometric measurements in the period of 2004-2010 at six AERO-NET monitoring sites on the territory of Russia: Zvenigorod, Moscow, Yekaterinburg, Tomsk, Yakutsk, and Ussuriisk.

  15. Topology of Document Retrieval Systems.

    ERIC Educational Resources Information Center

    Everett, Daniel M.; Cater, Steven C.

    1992-01-01

    Explains the use of a topological structure to examine the closeness between documents in retrieval systems and analyzes the topological structure of a vector-space model, a fuzzy-set model, an extended Boolean model, a probabilistic model, and a TIRS (Topological Information Retrieval System) model. Proofs for the results are appended. (17…

  16. Intelligent Information Retrieval: An Introduction.

    ERIC Educational Resources Information Center

    Gauch, Susan

    1992-01-01

    Discusses the application of artificial intelligence to online information retrieval systems and describes several systems: (1) CANSEARCH, from MEDLINE; (2) Intelligent Interface for Information Retrieval (I3R); (3) Gausch's Query Reformulation; (4) Environmental Pollution Expert (EP-X); (5) PLEXUS (gardening); and (6) SCISOR (corporate…

  17. Detecting Mood-Dependent Retrieval.

    ERIC Educational Resources Information Center

    Mayer, John D.; Bower, Gordon H.

    The mood-dependent retrieval hypothesis states that mood will enhance recall by acting as a recall cue if the stimuli have been learned initially in the same mood. Material learned in a happy mood will be best recalled when the person returns to a happy mood; the same holds for a sad mood. Mood-dependent retrieval effect has been regulary…

  18. Indexing Theory and Retrieval Effectiveness.

    ERIC Educational Resources Information Center

    Robertson, Stephen E.

    1978-01-01

    Describes recent attempts to make explicit connections between the indexing process and the use of the index or information retrieval system, particularly the utility-theoretic and automatic indexing models of William Cooper and Stephen Harter. Theory and performance, information storage and retrieval, search stage feedback, and indexing are also…

  19. Document Retrieval: A Structural Approach.

    ERIC Educational Resources Information Center

    Lu, Xin

    1990-01-01

    Describes the development of a structural model of document retrieval based on lexical-semantic relationships between index terms. An algorithm that uses tree-to-tree distance to measure structural closeness between a document and a query statement is explained, and the proposed model is compared to a vector retrieval model. (18 references) (LRW)

  20. Passage Retrieval: A Probabilistic Technique.

    ERIC Educational Resources Information Center

    Melucci, Massimo

    1998-01-01

    Presents a probabilistic technique to retrieve passages from texts having a large size or heterogeneous semantic content. Results of experiments comparing the probabilistic technique to one based on a text segmentation algorithm revealed that the passage size affects passage retrieval performance; text organization and query generality may have an…

  1. Phase retrieval tomography in the presence of noise

    NASA Astrophysics Data System (ADS)

    Arhatari, B. D.; Gates, W. P.; Eshtiaghi, N.; Peele, A. G.

    2010-02-01

    We describe the use of single-plane phase retrieval tomography using a laboratory-based x-ray source, under conditions where the retrieval is not formally valid, to present images of the internal structure of an Aerosil granule and a hydrated bentonite gel. The technique provides phase images for samples that interact weakly with the x-ray beam. As the method is less affected by noise than an alternative two-plane phase retrieval method that is otherwise formally valid, object structure can be observed that would not otherwise be seen. We demonstrate our results for phase imaging in tomographic measurements.

  2. An improved glyoxal retrieval from OMI measurements

    NASA Astrophysics Data System (ADS)

    Alvarado, L. M. A.; Richter, A.; Vrekoussis, M.; Wittrock, F.; Hilboll, A.; Schreier, S. F.; Burrows, J. P.

    2014-06-01

    Satellite observations from the SCIAMACHY, GOME-2, and OMI spectrometers have been used to retrieve atmospheric columns of glyoxal (CHOCHO) with the DOAS method. High CHOCHO levels are found over regions with large biogenic and pyrogenic emissions, and hot-spots have been identified over areas of anthropogenic activities. This study focuses on the development of an improved retrieval for CHOCHO from measurements by the OMI instrument. From sensitivity tests, an optimal fitting window and polynomial degree are determined. Two different approaches to reduce the interference of liquid water absorption over oceanic regions are evaluated, achieving significant reduction of negative columns over clear water regions. Moreover, a high temperature absorption cross-section of nitrogen dioxide (NO2) is introduced in the DOAS retrieval to account for potential interferences of NO2 over regions with large anthropogenic emissions, leading to improved fit quality over these areas. A comparison with vertical CHOCHO columns retrieved from measurements of the GOME-2 and SCIAMACHY instruments over continental regions is performed, showing overall good consistency. Using the new OMI CHOCHO data set, the link between fires and glyoxal columns is investigated for two selected regions in Africa. In addition, mapped averages are computed for a fire event in the east of Moscow between mid-July and mid-August 2010. In both cases, enhanced CHOCHO levels are found in close spatial and temporal proximity to MODIS fire radiative power, demonstrating that pyrogenic emissions can be clearly identified in the OMI CHOCHO product.

  3. Exploring biases in exoplanet spectroscopy retrievals

    NASA Astrophysics Data System (ADS)

    Feng, Ying; Fortney, Jonathan; Line, Michael R.; Morley, Caroline

    2015-12-01

    Spectra from the atmospheres of transiting planets and imaged planets are now being routinely achieved. The interpretation of these spectra gives us a window into the physics and chemistry of these atmospheres, as well as a better understanding of planet formation. Over the past several years retrievals of exoplanet spectra have been used to obtain chemical abundances and thermal structures, along with assessments of uncertainties on these quantities. However, any potential biases inherent in these methods have yet to be fully explored. The atmospheres we observe are inherently three-dimensional (3D) structures that feature gradients in temperatures and chemical abundances, as well as hot spots, cold spots, storms, and cloud patchiness. How well does the assumption of retrieving 1D hemispheric average conditions represent the true state of a 3D atmosphere? Can we be led astray? Answering these questions are important today, and will only become more important as data quality improves. Using a descendent of the CHIMERA retrieval code, here I present the results of how retrievals perform on more complex scenarios. We start with the emitted spectrum from the average of two pressure-temperature profiles, one warmer, one colder, and move on to more sophisticated, but still realistic, scenarios. Our work makes use of a new code we have developed to construct spectra from arbitrary 3D model atmospheres.

  4. Retrieval and classification of dental research articles.

    PubMed

    Bartling, W C; Schleyer, T K; Visweswaran, S

    2003-12-01

    Successful retrieval of a corpus of literature on a broad topic can be difficult. This study demonstrates a method to retrieve the dental and craniofacial research literature. We explored MeSH manually for dental or craniofacial indexing terms. MEDLINE was searched using these terms, and a random sample of references was extracted from the resulting set. Sixteen dental research experts categorized these articles, reading only the title and abstract, as either: (1) dental research, (2) dental non-research, (3) non-dental, or (4) not sure. Identify Patient Sets (IPS), a probabilistic text classifier, created models, based on the presence or absence of words or UMLS phrases, that distinguished dental research articles from all others. These models were applied to a test set with different inputs for each article: (1) title and abstract only, (2) MeSH terms only, or (3) both. By title and abstract only, IPS correctly classified 64% of all dental research articles present in the test set. The percentage of correctly classified dental research articles in this retrieved set was 71%. MeSH term inclusion decreased performance. Computer programs that use text input to categorize articles may aid in retrieval of a broad corpus of literature better than indexing terms or key words alone.

  5. Immune recognition of protein antigens

    SciTech Connect

    Laver, W.G.; Air, G.M.

    1985-01-01

    This book contains 33 papers. Some of the titles are: Antigenic Structure of Influenze Virus Hemagglutinin; Germ-line and Somatic Diversity in the Antibody Response to the Influenza Virus A/PR/8/34 Hemagglutinin; Recognition of Cloned Influenza A Virus Gene Products by Cytotoxic T Lymphocytes; Antigenic Structure of the Influenza Virus N2 Neuraminidase; and The Molecular and Genetic Basis of Antigenic Variation in Gonococcal Pillin.

  6. Antigenic cartographic analysis of H7 avian influenza viruses with chicken serum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Antigenic cartography is a relatively new method that can be used to evaluate the antigenic relatedness among avian influenza virus isolates. Evaluation of antigenic relationships among avian influenza viruses can be applied to vaccine design and to understanding the evolution of the virus. Initia...

  7. Use of antigenic cartography in vaccine seed strain selection.

    PubMed

    Fouchier, Ron A M; Smith, Derek J

    2010-03-01

    Human influenza A viruses are classic examples of antigenically variable pathogens that have a seemingly endless capacity to evade the host's immune response. The viral hemagglutinin (HA) and neuraminidase (NA) proteins are the main targets of our antibody response to combat infections. HA and NA continuously change to escape from humoral immunity, a process known as antigenic drift. As a result of antigenic drift, the human influenza vaccine is updated frequently. The World Health Organization (WHO) coordinates a global influenza surveillance network that, by the hemagglutination inhibition (HI) assay, routinely characterizes the antigenic properties of circulating strains in order to select new seed viruses for such vaccine updates. To facilitate a quantitative interpretation and easy visualization of HI data, a new computational technique called "antigenic cartography" was developed. Since its development, antigenic cartography has been applied routinely to assist the WHO with influenza surveillance activities. Until recently, antigenic variation was not considered a serious issue with influenza vaccines for poultry. However, because of the diversification of the Asian H5N1 lineage since 1996 into multiple genetic clades and subclades, and because of the long-term use of poultry vaccines against H5 in some parts of the world, this issue needs to be re-addressed. The antigenic properties of panels of avian H5N1 viruses were characterized by HI assay, using mammalian or avian antisera, and analyzed using antigenic cartography methods. These analyses revealed antigenic differences between circulating H5N1 viruses and the H5 viruses used in poultry vaccines. Considerable antigenic variation was also observed within and between H5N1 clades. These observations have important implications for the efficacy and long-term use of poultry vaccines.

  8. Web Mining for Web Image Retrieval.

    ERIC Educational Resources Information Center

    Chen, Zheng; Wenyin, Liu; Zhang, Feng; Li, Mingjing; Zhang, Hongjiang

    2001-01-01

    Presents a prototype system for image retrieval from the Internet using Web mining. Discusses the architecture of the Web image retrieval prototype; document space modeling; user log mining; and image retrieval experiments to evaluate the proposed system. (AEF)

  9. Launchable and Retrievable Tetherobot

    NASA Technical Reports Server (NTRS)

    Younse, Paulo; Aghazarian, Hrand

    2010-01-01

    A proposed robotic system for scientific exploration of rough terrain would include a stationary or infrequently moving larger base robot, to which would be tethered a smaller hopping robot of the type described in the immediately preceding article. The two-robot design would extend the reach of the base robot, making it possible to explore nearby locations that might otherwise be inaccessible or too hazardous for the base robot. The system would include a launching mechanism and a motor-driven reel on the larger robot. The outer end of the tether would be attached to the smaller robot; the inner end of the tether would be attached to the reel. The figure depicts the launching and retrieval process. The launching mechanism would aim and throw the smaller robot toward a target location, and the tether would be paid out from the reel as the hopping robot flew toward the target. Upon completion of exploratory activity at the target location, the smaller robot would be made to hop and, in a coordinated motion, the tether would be wound onto the reel to pull the smaller robot back to the larger one.

  10. Montana StreamStats—A method for retrieving basin and streamflow characteristics in Montana: Chapter A in Montana StreamStats

    USGS Publications Warehouse

    McCarthy, Peter M.; Dutton, DeAnn M.; Sando, Steven K.; Sando, Roy

    2016-04-05

    The U.S. Geological Survey (USGS) provides streamflow characteristics and other related information needed by water-resource managers to protect people and property from floods, plan and manage water-resource activities, and protect water quality. Streamflow characteristics provided by the USGS, such as peak-flow and low-flow frequencies for streamflow-gaging stations, are frequently used by engineers, flood forecasters, land managers, biologists, and others to guide their everyday decisions. In addition to providing streamflow characteristics at streamflow-gaging stations, the USGS also develops regional regression equations and drainage area-adjustment methods for estimating streamflow characteristics at locations on ungaged streams. Regional regression equations can be complex and often require users to determine several basin characteristics, which are physical and climatic characteristics of the stream and its drainage basin. Obtaining these basin characteristics for streamflow-gaging stations and ungaged sites traditionally has been time consuming and subjective, and led to inconsistent results.StreamStats is a Web-based geographic information system application that was created by the USGS to provide users with access to an assortment of analytical tools that are useful for water-resource planning and management. StreamStats allows users to easily obtain streamflow and basin characteristics for USGS streamflow-gaging stations and user-selected locations on ungaged streams. The USGS, in cooperation with Montana Department of Transportation, Montana Department of Environmental Quality, and Montana Department of Natural Resources and Conservation, completed a study to develop a StreamStats application for Montana, compute streamflow characteristics at streamflow-gaging stations, and develop regional regression equations to estimate streamflow characteristics at ungaged sites. Chapter A of this Scientific Investigations Report describes the Montana Stream

  11. Antigenic variation in ciliates: antigen structure, function, expression.

    PubMed

    Simon, Martin C; Schmidt, Helmut J

    2007-01-01

    In the past decades, the major focus of antigen variation research has been on parasitic protists. However, antigenic variation occurs also in free-living protists. The antigenic systems of the ciliates Paramecium and Tetrahymena have been studied for more than 100 yr. In spite of different life strategies and distant phylogenetic relationships of free-living ciliates and parasitic protists, their antigenic systems have features in common, such as the presence of repeated protein motifs and multigene families. The function of variable surface antigens in free-living ciliates is still unknown. Up to now no detailed monitoring of antigen expression in free-living ciliates in natural habitats has been performed. Unlike stochastic switching in parasites, antigen expression in ciliates can be directed, e.g. by temperature, which holds great advantages for research on the expression mechanism. Regulated expression of surface antigens occurs in an exclusive way and the responsible mechanism is complex, involving both transcriptional and post-transcriptional features. The involvement of homology-dependent effects has been proposed several times but has not been proved yet.

  12. Solid rocket booster retrieval operations

    NASA Technical Reports Server (NTRS)

    Rasmussen, A. M.

    1985-01-01

    Solid Rocket Booster Retrieval operations are discussed in detail. The recovery of expended boosters and associated hardware without damage attributable to retrieval procedures is the main goal. The retrieval force consists tof ship's personnel and retrieval team members, each of whom has been trained and is highly skilled in multi-faceted operations. The retrieval force is equipped with two specially-built, highly maneuverable ships outfitted with parachute reels, retrieval cranes, towing winches, large volume-low pressure air compressors, SCUBA diving gear, inflatable boats with outboard motors and diver-operated SRB dewatering devices. The two ships are deployed in sufficient time to conduct an electronic and visual search of the impact area prior to launch. Upon search completeion, each ship takes station a safe distance from the predetermined impact point initiating both visual and electronic search in the direction of flight path, ensuring SRB acquisition at splashdown. When safe, the ships enter the impact area and commence recovery of all floating flight hardware which is subsequently returned to the Disassembly Facility for refurbishment and reuse. Retrieval techniques have evolved in parallel with equipment and flight hardware configuration changes. Additional changes have been initiated to improve personnel safety.

  13. Artificial antigen presenting cells for use in adoptive immunotherapy

    PubMed Central

    Turtle, Cameron J.; Riddell, Stanley R.

    2010-01-01

    The observation that T cells can recognize and specifically eliminate cancer cells has spurred interest in the development of efficient methods to generate large numbers of T cells with specificity for tumor antigens that can be harnessed for use in cancer therapy. Recent studies have demonstrated that during encounter with tumor antigen, the signals delivered to T cells by professional antigen presenting cells can affect T cell programming and their subsequent therapeutic efficacy. This has stimulated efforts to develop artificial antigen presenting cells that allow optimal control over the signals provided to T cells. In this review, we will discuss the advantages and disadvantages of cellular and acellular artificial antigen presenting cell systems and their use in T cell adoptive immunotherapy for cancer. PMID:20693850

  14. Artificial antigen-presenting cells for use in adoptive immunotherapy.

    PubMed

    Turtle, Cameron J; Riddell, Stanley R

    2010-01-01

    The observation that T cells can recognize and specifically eliminate cancer cells has spurred interest in the development of efficient methods to generate large numbers of T cells with specificity for tumor antigens that can be harnessed for use in cancer therapy. Recent studies have demonstrated that during encounter with tumor antigen, the signals delivered to T cells by professional antigen-presenting cells can affect T-cell programming and their subsequent therapeutic efficacy. This has stimulated efforts to develop artificial antigen-presenting cells that allow optimal control over the signals provided to T cells. In this review, we will discuss the advantages and disadvantages of cellular and acellular artificial antigen-presenting cell systems and their use in T-cell adoptive immunotherapy for cancer. PMID:20693850

  15. Targeting Antigens to Dendritic Cell Receptors for Vaccine Development

    PubMed Central

    Apostolopoulos, Vasso; Thalhammer, Theresia; Tzakos, Andreas G.

    2013-01-01

    Dendritic cells (DCs) are highly specialized antigen presenting cells of the immune system which play a key role in regulating immune responses. Depending on the method of antigen delivery, DCs stimulate immune responses or induce tolerance. As a consequence of the dual function of DCs, DCs are studied in the context of immunotherapy for both cancer and autoimmune diseases. In vaccine development, a major aim is to induce strong, specific T-cell responses. This is achieved by targeting antigen to cell surface molecules on DCs that efficiently channel the antigen into endocytic compartments for loading onto MHC molecules and stimulation of T-cell responses. The most attractive cell surface receptors, expressed on DCs used as targets for antigen delivery for cancer and other diseases, are discussed. PMID:24228179

  16. Regularization for Atmospheric Temperature Retrieval Problems

    NASA Technical Reports Server (NTRS)

    Velez-Reyes, Miguel; Galarza-Galarza, Ruben

    1997-01-01

    Passive remote sensing of the atmosphere is used to determine the atmospheric state. A radiometer measures microwave emissions from earth's atmosphere and surface. The radiance measured by the radiometer is proportional to the brightness temperature. This brightness temperature can be used to estimate atmospheric parameters such as temperature and water vapor content. These quantities are of primary importance for different applications in meteorology, oceanography, and geophysical sciences. Depending on the range in the electromagnetic spectrum being measured by the radiometer and the atmospheric quantities to be estimated, the retrieval or inverse problem of determining atmospheric parameters from brightness temperature might be linear or nonlinear. In most applications, the retrieval problem requires the inversion of a Fredholm integral equation of the first kind making this an ill-posed problem. The numerical solution of the retrieval problem requires the transformation of the continuous problem into a discrete problem. The ill-posedness of the continuous problem translates into ill-conditioning or ill-posedness of the discrete problem. Regularization methods are used to convert the ill-posed problem into a well-posed one. In this paper, we present some results of our work in applying different regularization techniques to atmospheric temperature retrievals using brightness temperatures measured with the SSM/T-1 sensor. Simulation results are presented which show the potential of these techniques to improve temperature retrievals. In particular, no statistical assumptions are needed and the algorithms were capable of correctly estimating the temperature profile corner at the tropopause independent of the initial guess.

  17. Retrieving the vertical distribution of chlorophyll a concentration and phytoplankton community composition from in situ fluorescence profiles: A method based on a neural network with potential for global-scale applications

    NASA Astrophysics Data System (ADS)

    Sauzède, R.; Claustre, H.; Jamet, C.; Uitz, J.; Ras, J.; Mignot, A.; D'Ortenzio, F.

    2015-01-01

    neural network-based method is developed to assess the vertical distribution of (1) chlorophyll a concentration ([Chl]) and (2) phytoplankton community size indices (i.e., microphytoplankton, nanophytoplankton, and picophytoplankton) from in situ vertical profiles of chlorophyll fluorescence. This method (FLAVOR for Fluorescence to Algal communities Vertical distribution in the Oceanic Realm) uses as input only the shape of the fluorescence profile associated with its acquisition date and geo-location. The neural network is trained and validated using a large database including 896 concomitant in situ vertical profiles of High-Performance Liquid Chromatography (HPLC) pigments and fluorescence. These profiles were collected during 22 oceanographic cruises representative of the global ocean in terms of trophic and oceanographic conditions, making our method applicable to most oceanic waters. FLAVOR is validated with respect to the retrieval of both [Chl] and phytoplankton size indices using an independent in situ data set and appears to be relatively robust spatially and temporally. To illustrate the potential of the method, we applied it to in situ measurements of the BATS (Bermuda Atlantic Time Series Study) site and produce monthly climatologies of [Chl] and associated phytoplankton size indices. The resulting climatologies appear very promising compared to climatologies based on available in situ HPLC data. With the increasing availability of spatially and temporally well-resolved data sets of chlorophyll fluorescence, one possible global-scale application of FLAVOR could be to develop 3-D and even 4-D climatologies of [Chl] and associated composition of phytoplankton communities. The Matlab and R codes of the proposed algorithm are provided as supporting information.

  18. O-antigen and virulence profiling of Shiga toxin-producing Escherichia coli by a rapid and cost-effective DNA microarray colorimetric method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Shiga toxin-producing Escherichia coli (STEC) is a leading cause of foodborne illness worldwide. To evaluate better methods to rapidly detect and genotype Shiga toxin-producing Escherichia coli strains, the present study evaluated the use of the ampliPHOX colorimetric detection technology, based on ...

  19. System For Retrieving Reusable Software

    NASA Technical Reports Server (NTRS)

    Van Warren, Lloyd; Beckman, Brian C.

    1993-01-01

    Encyclopedia of Software Components (ESC) is information-retrieval system of computer hardware and software providing access to generic reusable software tools and parts. Core of ESC is central tool base, which is repository of reusable software. It receives queries and submissions from user through local browser subsystem and receives authorized updates from maintenance subsystem. Sends retrievals to local browser subsystem and user's submissions to maintenance subsystem. Future versions will provide for advanced media, including voice and video, and will link system to database-management system. Programmers will not only retrieve software, but also modify, execute, and cross-link with other software.

  20. Mobile medical visual information retrieval.

    PubMed

    Depeursinge, Adrien; Duc, Samuel; Eggel, Ivan; Müller, Henning

    2012-01-01

    In this paper, we propose mobile access to peer-reviewed medical information based on textual search and content-based visual image retrieval. Web-based interfaces designed for limited screen space were developed to query via web services a medical information retrieval engine optimizing the amount of data to be transferred in wireless form. Visual and textual retrieval engines with state-of-the-art performance were integrated. Results obtained show a good usability of the software. Future use in clinical environments has the potential of increasing quality of patient care through bedside access to the medical literature in context.

  1. Enrichment of antigen-specific B lymphocytes by the direct removal of B cells not bearing specificity for the antigen

    PubMed Central

    1977-01-01

    Antigen-specific B cells (ASC) were purified from other B cells by prior incubation with specific antigen followed by rosetting with erythrocytes conjugated with anti-mouse Ig and sedimenting on Ficoll- Isopaque. This procedure allowed the removal of most of the B cells, while those speicifc for the antigen used in incubation were retained. Relative to the B-cell content, ASC were enriched 64- to 132-fold. The method is highly specific in that B cells primed to two different antigens, turkey gamma globulin and sheep erythrocytes, could be separated from each other. The advantages of this indirect purification procedure over purification procedures which obtain ASC directly are the simplicity of obtaining the ASC and the ability of the ASC of respond to antigen without the addition of other cells. PMID:69002

  2. Novel antigen delivery systems

    PubMed Central

    Trovato, Maria; Berardinis, Piergiuseppe De

    2015-01-01

    Vaccines represent the most relevant contribution of immunology to human health. However, despite the remarkable success achieved in the past years, many vaccines are still missing in order to fight important human pathologies and to prevent emerging and re-emerging diseases. For these pathogens the known strategies for making vaccines have been unsuccessful and thus, new avenues should be investigated to overcome the failure of clinical trials and other important issues including safety concerns related to live vaccines or viral vectors, the weak immunogenicity of subunit vaccines and side effects associated with the use of adjuvants. A major hurdle of developing successful and effective vaccines is to design antigen delivery systems in such a way that optimizes antigen presentation and induces broad protective immune responses. Recent advances in vector delivery technologies, immunology, vaccinology and system biology, have led to a deeper understanding of the molecular and cellular mechanisms by which vaccines should stimulate both arms of the adaptive immune responses, offering new strategies of vaccinations. This review is an update of current strategies with respect to live attenuated and inactivated vaccines, DNA vaccines, viral vectors, lipid-based carrier systems such as liposomes and virosomes as well as polymeric nanoparticle vaccines and virus-like particles. In addition, this article will describe our work on a versatile and immunogenic delivery system which we have studied in the past decade and which is derived from a non-pathogenic prokaryotic organism: the “E2 scaffold” of the pyruvate dehydrogenase complex from Geobacillus stearothermophilus. PMID:26279977

  3. Stool Test: H. Pylori Antigen

    MedlinePlus

    ... Things to Know About Zika & Pregnancy Stool Test: H. Pylori Antigen KidsHealth > For Parents > Stool Test: H. Pylori Antigen Print A A A Text Size ... en español Muestra de materia fecal: antígeno de H. pylori What It Is Helicobacter pylori ( H. pylori ) ...

  4. Differentiation antigens in lymphohemopoietic tissues

    SciTech Connect

    Miyasaka, M.; Trnka, Z.

    1988-01-01

    This book contains 15 chapters. Some of the chapter titles are: In Situ Characterization of Human Lymphoid Cells Using Monoclonal Antibodies; Structural and Functional Aspects of HLA Clas II Genes; Cell-Surface Differentiation Antigens Expressed on Thymocytes and T Cells of the Mouse; and Differentiation Antigens on Lymphoid Cells of the Guinea Pig.

  5. Scene change detection for video retrieval on MPEG streams

    NASA Astrophysics Data System (ADS)

    Kang, Eung-Kwan; Kim, Sung-Joo; Jahng, SurngGabb; Song, Ho-Keun; Choi, Jong S.

    2000-05-01

    IN this paper, we propose a new scene change detection (SCD) algorithm, and also provide a novel video-indexing scheme for fast content-based browsing and retrieval in video databases. We detect scene changes from the MPEG video sequence, and extract key frames to represent contents of a shot. Then, we perform the video indexing by applying the rosette pattern to the extracted key frames, and retrieve them. Our SCD method is better than the conventional ones in terms of the SCD performance. Moreover, by applying the rosette pattern for indexing, we can remarkably reduce the number of pixels required to index and excellently retrieve the video scene.

  6. Developments of aerosol retrieval algorithm for Geostationary Environmental Monitoring Spectrometer (GEMS) and the retrieval accuracy test

    NASA Astrophysics Data System (ADS)

    KIM, M.; Kim, J.; Jeong, U.; Ahn, C.; Bhartia, P. K.; Torres, O.

    2013-12-01

    A scanning UV-Visible spectrometer, the GEMS (Geostationary Environment Monitoring Spectrometer) onboard the GEO-KOMPSAT2B (Geostationary Korea Multi-Purpose Satellite) is planned to be launched in geostationary orbit in 2018. The GEMS employs hyper-spectral imaging with 0.6 nm resolution to observe solar backscatter radiation in the UV and Visible range. In the UV range, the low surface contribution to the backscattered radiation and strong interaction between aerosol absorption and molecular scattering can be advantageous in retrieving aerosol optical properties such as aerosol optical depth (AOD) and single scattering albedo (SSA). By taking the advantage, the OMI UV aerosol algorithm has provided information on the absorbing aerosol (Torres et al., 2007; Ahn et al., 2008). This study presents a UV-VIS algorithm to retrieve AOD and SSA from GEMS. The algorithm is based on the general inversion method, which uses pre-calculated look-up table with assumed aerosol properties and measurement condition. To obtain the retrieval accuracy, the error of the look-up table method occurred by the interpolation of pre-calculated radiances is estimated by using the reference dataset, and the uncertainties about aerosol type and height are evaluated. Also, the GEMS aerosol algorithm is tested with measured normalized radiance from OMI, a provisional data set for GEMS measurement, and the results are compared with the values from AERONET measurements over Asia. Additionally, the method for simultaneous retrieve of the AOD and aerosol height is discussed.

  7. Carbohydrate-Mediated Targeting of Antigen to Dendritic Cells Leads to Enhanced Presentation of Antigen to T Cells

    PubMed Central

    Adams, Eddie W.; Ratner, Daniel M.; Seeberger, Peter H.; Hacohen, Nir

    2009-01-01

    The unique therapeutic value of dendritic cells (DCs) for the treatment of allergy, autoimmunity and transplant rejection is predicated upon our ability to selectively deliver antigens, drugs or nucleic acids to DCs in vivo. Here we describe a method for delivering whole protein antigens to DCs based on carbohydrate-mediated targeting of DC-expressed lectins. A series of synthetic carbohydrates was chemically-coupled to a model antigen, ovalbumin (OVA), and each conjugate was evaluated for its ability to increase the efficiency of antigen presentation by murine DCs to OVA-specific T cells (CD4+ and CD8+). In vitro data are presented that demonstrate that carbohydrate modification of OVA leads to a 50-fold enhancement of presentation of antigenic peptide to CD4+ T cells. A tenfold enhancement is observed for CD8+ T cells; this indicates that the targeted lectin(s) can mediate cross-presentation of antigens on MHC class I. Our data indicate that the observed enhancements in antigen presentation are unique to OVA that is conjugated to complex oligosaccharides, such as a high-mannose nonasaccharide, but not to monosaccharides. Taken together, our data suggest that a DC targeting strategy that is based upon carbohydrate-lectin interactions is a promising approach for enhancing antigen presentation via class I and class II molecules. PMID:18186095

  8. Autoradiographic detection of (/sup 125/I)-secondary antiserum: a sensitive light and electron microscopic labeling method compatible with peroxidase immunocytochemistry for dual localization of neuronal antigens

    SciTech Connect

    Pickel, V.M.; Chan, J.; Milner, T.A.

    1986-06-01

    We examined whether autoradiographic localization of (/sup 125/I)-antirabbit immunoglobulin (IgG) was suitable for light and electron microscopic detection of a rabbit antiserum to the catecholamine-synthesizing enzyme, tyrosine hydroxylase (TH), and whether autoradiographic and peroxidase labeling could be combined for simultaneous immunocytochemical identification of TH and neuropeptides in brain. Adult rat brains were fixed by aortic arch perfusion with acrolein and paraformaldehyde. Vibratome sections of the fixed tissues were incubated with various dilutions of TH antiserum followed by (/sup 125/I)-secondary IgG. These sections were then directly processed for autoradiography or were incubated with rabbit antiserum to substance P (SP) or methionine (Met5)-enkephalin (ME). These latter sections were then processed by the peroxidase-antiperoxidase (PAP) or conjugated peroxidase methods followed by autoradiography. Exposure periods of 12-20 days for light microscopy or 90 days for electron microscopy yielded substantial accumulations of silver grains even at the highest (1:30,000) dilution of TH antiserum. At this dilution, immunoreactivity for TH was virtually nondetectable by PAP and conjugated peroxidase methods. The differential sensitivities of the autoradiographic versus peroxidase methods provided a means for separable identification of rabbit antiserum to TH and to SP or ME. Ultrastructural analysis of the catecholaminergic neurons in the medial nuclei of the solitary tract (NTS) showed selective cytoplasmic localization of silver grains for (/sup 125/I)-labeling of TH in perikarya, dendrites, and terminals. Within single thin sections prepared for dual labeling, the peroxidase marker for SP and for ME was differentially localized with respect to autoradiographic labeling of TH.

  9. Radioimmunoassays of hidden viral antigens

    SciTech Connect

    Neurath, A.R.; Strick, N.; Baker, L.; Krugman, S.

    1982-07-01

    Antigens corresponding to infectious agents may be present in biological specimens only in a cryptic form bound to antibodies and, thus, may elude detection. We describe a solid-phase technique for separation of antigens from antibodies. Immune complexes are precipitated from serum by polyethylene glycol, dissociated with NaSCN, and adsorbed onto nitrocellulose or polystyrene supports. Antigens remain topographically separated from antibodies after removal of NaSCN and can be detected with radiolabeled antibodies. Genomes from viruses immobilized on nitrocellulose can be identified by nucleic acid hybridization. Nanogram quantities of sequestered hepatitis B surface and core antigens and picogram amounts of hepatitis B virus DNA were detected. Antibody-bound adenovirus, herpesvirus, and measles virus antigens were discerned by the procedure.

  10. Phase retrieval using nonlinear diversity.

    PubMed

    Lu, Chien-Hung; Barsi, Christopher; Williams, Matthew O; Kutz, J Nathan; Fleischer, Jason W

    2013-04-01

    We extend the Gerchberg-Saxton algorithm to phase retrieval in a nonlinear system. Using a tunable photorefractive crystal, we experimentally demonstrate the noninterferometric technique by reconstructing an unknown phase object from optical intensity measurements taken at different nonlinear strengths.

  11. Cranfield Conference on Information Retrieval.

    ERIC Educational Resources Information Center

    Kuo, Franklin F.

    The Third Cranfield Conference on Mechanised Information Storage and Retrieval Systems was held on 20-23 July 1971 in Cranfield, England. The report describes a number of the key papers presented at this conference. (Author)

  12. Catalogue Retrieval: A Library Economy

    ERIC Educational Resources Information Center

    Ready, William

    1970-01-01

    An evaluation of the Information Dynamics Corporation Retrieval System in an academic library, describing the specification of the machine and the various reader printers tested at Mills Memorial Library, McMaster University. (Author)

  13. F/NAS/Pressure Temperature Retrieval Techniques

    NASA Technical Reports Server (NTRS)

    Poularikas. Alexander

    1998-01-01

    The purpose of this investigation is to study methods and ways for rapid inversion programs involving the correlated k-method, and to modify the existing programs so that the rapid analysis of data can be accomplished. Extensive modifications of the software programs were introduced. These modifications were imposed on the radiative transfer models and inversion methods and resulted in incorporating some important atmospheric processes not previously considered. The software also was improved to handle several toxic gases, gases that were observed in Saturn's atmosphere, and to retrieve pressure-temperature profiles from infrared solar absorption spectra.

  14. [Spectral curve shape feature-based hyperspectral remote sensing image retrieval].

    PubMed

    Li, Fei; Zhou, Cheng-Hu; Chen, Rong-Guo

    2008-11-01

    With the rapid development of technology of sensors and data transmission, using all kinds of airplane sensors and satellite sensors, the authors can get different voluminous remote sensing image data of earth. Those voluminous remote sensing image data bring problems of data storage and management. It is becoming increasingly necessary to retrieve some information the authors need from those voluminous image data. Image retrieval was proposed by CHANG firstly in 1980 and can be regarded as expansion of traditional information retrieval. Oriented to the demands of efficient retrieval for voluminous remote sensing image, and considering that there are many bands in hyperspectral remote sensing image, the authors first analyzed image distance function and similarity measure in image retrieval. The most crucial issues in retrieval are spectral features extraction and similarity measure. In the present paper, the authors used classical Douglas-Peucker algorithm (hereinafter referred to DP algorithm) for curve simplification to extract shape features of spectral curve, in order to speed up hyperspectral remote sensing image retrieval. And the authors proposed a new method of spectral curve and remote sensing image retrieval, called Douglas-Peucker Spectral Retrieval algorithm (hereinafter referred to DPSR algorithm). Spectral shape features were used in image retrieval. DPSR used features of spectral curve, reduced the computation amount, realized match and retrieval efficiently, and is suitable for spectral curve retrieval in hyperspectral remote sensing image. The authors selected four ground features (grass, apple garden, grape garden and pond) in OMISI hyperspectral remote sensing image to compute similarity measure results, in order to test the effect of DPSR algorithm. Compared with traditional analysis method such as spectral angle match (SAM) and spectral information divergence (SID), DPSR can maintain high precision of results with less amount of computation

  15. An Exponentiation Method for XML Element Retrieval

    PubMed Central

    2014-01-01

    XML document is now widely used for modelling and storing structured documents. The structure is very rich and carries important information about contents and their relationships, for example, e-Commerce. XML data-centric collections require query terms allowing users to specify constraints on the document structure; mapping structure queries and assigning the weight are significant for the set of possibly relevant documents with respect to structural conditions. In this paper, we present an extension to the MEXIR search system that supports the combination of structural and content queries in the form of content-and-structure queries, which we call the Exponentiation function. It has been shown the structural information improve the effectiveness of the search system up to 52.60% over the baseline BM25 at MAP. PMID:24696643

  16. An exponentiation method for XML element retrieval.

    PubMed

    Wichaiwong, Tanakorn

    2014-01-01

    XML document is now widely used for modelling and storing structured documents. The structure is very rich and carries important information about contents and their relationships, for example, e-Commerce. XML data-centric collections require query terms allowing users to specify constraints on the document structure; mapping structure queries and assigning the weight are significant for the set of possibly relevant documents with respect to structural conditions. In this paper, we present an extension to the MEXIR search system that supports the combination of structural and content queries in the form of content-and-structure queries, which we call the Exponentiation function. It has been shown the structural information improve the effectiveness of the search system up to 52.60% over the baseline BM25 at MAP.

  17. An exponentiation method for XML element retrieval.

    PubMed

    Wichaiwong, Tanakorn

    2014-01-01

    XML document is now widely used for modelling and storing structured documents. The structure is very rich and carries important information about contents and their relationships, for example, e-Commerce. XML data-centric collections require query terms allowing users to specify constraints on the document structure; mapping structure queries and assigning the weight are significant for the set of possibly relevant documents with respect to structural conditions. In this paper, we present an extension to the MEXIR search system that supports the combination of structural and content queries in the form of content-and-structure queries, which we call the Exponentiation function. It has been shown the structural information improve the effectiveness of the search system up to 52.60% over the baseline BM25 at MAP. PMID:24696643

  18. Retrieval of atmospheric properties with radiometric measurements using neural network

    NASA Astrophysics Data System (ADS)

    Chakraborty, Rohit; Maitra, Animesh

    2016-11-01

    Microwave radiometer is an effective instrument to monitor the atmosphere continuously in different weather conditions. It measures brightness temperatures at different frequency bands which are subjected to standard retrieval methods to obtain real time profiles of various atmospheric parameters such as temperature and humidity. But the retrieval techniques used by radiometer have to be adaptive to changing weather condition and location. In the present study, three retrieval techniques have been used to obtain the temperature and relative humidity profiles from brightness temperatures, namely; piecewise linear regression, feed forward neural network and neural back propagation network. The simulated results are compared with radiosonde observations using correlation analysis and error distribution. The analysis reveals that neural network with back propagation is the most accurate technique amongst the three retrieval methods utilized in this study.

  19. Spaced retrieval treatment of anomia

    PubMed Central

    Fridriksson, Julius; Holland, Audrey L.; Beeson, Pélagie; Morrow, Leigh

    2006-01-01

    Background Spaced Retrieval (SR) is a treatment approach developed to facilitate recall of information by individuals with dementia. Essentially an errorless learning procedure that can be used to facilitate recall of a variety of information, SR gradually increases the interval between correct recall of target items. Aims Given the success of using SR in dementia, the purpose of this study was to explore its usefulness in improving naming by individuals with aphasia. The rate of acquisition and retention of items was compared between SR and a more traditional treatment technique—cueing hierarchy (CH). Also, each oral naming treatment was run concurrently with a single word writing treatment. Methods & Procedures Three participants who had moderate or severe naming impairments and agraphia were studied. Single-subject design was applied across oral and written naming and treated and untreated items. Outcomes & Results The results indicate that for these participants, SR resulted in improved naming of specific items. The data further suggest that SR compared favourably to CH with regard to both acquisition and retention of items. The participants also benefited nicely from the writing treatment. Conclusions These findings suggest SR may be an alternative for managing naming impairment resulting from aphasia. Furthermore, the study supports providing treatments aimed at two different modalities concurrently. PMID:16823467

  20. Polar Embedding for Aurora Image Retrieval.

    PubMed

    Yang, Xi; Gao, Xinbo; Tian, Qi

    2015-11-01

    Exploring the multimedia techniques to assist scientists for their research is an interesting and meaningful topic. In this paper, we focus on the large-scale aurora image retrieval by leveraging the bag-of-visual words (BoVW) framework. To refine the unsuitable representation and improve the retrieval performance, the BoVW model is modified by embedding the polar information. The superiority of the proposed polar embedding method lies in two aspects. On the one hand, the polar meshing scheme is conducted to determine the interest points, which is more suitable for images captured by circular fisheye lens. Especially for the aurora image, the extracted polar scale-invariant feature transform (polar-SIFT) feature can also reflect the geomagnetic longitude and latitude, and thus facilitates the further data analysis. On the other hand, a binary polar deep local binary pattern (polar-DLBP) descriptor is proposed to enhance the discriminative power of visual words. Together with the 64-bit polar-SIFT code obtained via Hamming embedding, the multifeature index is performed to reduce the impact of false positive matches. Extensive experiments are conducted on the large-scale aurora image data set. The experimental result indicates that the proposed method improves the retrieval accuracy significantly with acceptable efficiency and memory cost. In addition, the effectiveness of the polar-SIFT scheme and polar-DLBP integration are separately demonstrated. PMID:26068312

  1. Neural mechanisms of extinction learning and retrieval.

    PubMed

    Quirk, Gregory J; Mueller, Devin

    2008-01-01

    Emotional learning is necessary for individuals to survive and prosper. Once acquired, however, emotional associations are not always expressed. Indeed, the regulation of emotional expression under varying environmental conditions is essential for mental health. The simplest form of emotional regulation is extinction, in which conditioned responding to a stimulus decreases when the reinforcer is omitted. Two decades of research on the neural mechanisms of fear conditioning have laid the groundwork for understanding extinction. In this review, we summarize recent work on the neural mechanisms of extinction learning. Like other forms of learning, extinction occurs in three phases: acquisition, consolidation, and retrieval, each of which depends on specific structures (amygdala, prefrontal cortex, hippocampus) and molecular mechanisms (receptors and signaling pathways). Pharmacological methods to facilitate consolidation and retrieval of extinction, for both aversive and appetitive conditioning, are setting the stage for novel treatments for anxiety disorders and addictions.

  2. Neural Mechanisms of Extinction Learning and Retrieval

    PubMed Central

    Quirk, Gregory J.; Mueller, Devin

    2009-01-01

    Emotional learning is necessary for individuals to survive and prosper. Once acquired, however, emotional associations are not always expressed. Indeed, the regulation of emotional expression under varying environmental conditions is essential for mental health. The simplest form of emotional regulation is extinction, in which conditioned responding to a stimulus decreases when the reinforcer is omitted. Two decades of research on the neural mechanisms of fear conditioning have laid the groundwork for understanding extinction. In this review, we summarize recent work on the neural mechanisms of extinction learning. Like other forms of learning, extinction occurs in three phases: acquisition, consolidation, and retrieval, each of which depends on specific structures (amygdala, prefrontal cortex, hippocampus), and molecular mechanisms (receptors and signaling pathways). Pharmacological methods to facilitate consolidation and retrieval of extinction, for both aversive and appetitive conditioning, are setting the stage for novel treatments for anxiety disorders and addictions. PMID:17882236

  3. Content based retrieval of lesioned brain images

    NASA Astrophysics Data System (ADS)

    Batty, Stephen; Blandford, Ann; Clark, John; Fryer, Tim; Gao, Xiaohong

    2002-05-01

    HI-PACS enable more efficient data-management leading to increased operating efficiency and therefore better patient care, a content based pet image retrieval system would contribute to the development of a HI-PACS. A database of PET neuro-images has been created with a facility for retrieving via visual content. The adaptation of algorithms developed for alternate imaging modalities (eg-MRI) formed the basis of feature detection and measurement algorithms. The application of these algorithms to greyscale PET images results in data that is employed as database indices and similarity metrics. The feature detection and measurement algorithms can be split into two different methods. The first uses the extracted ideal mid sagittal symmetry line to detect differences between the two hemisphere of the brain, while the second utilizes Gabor filters to measure the texture of the whole brain.

  4. Image retrieval for identifying house plants

    NASA Astrophysics Data System (ADS)

    Kebapci, Hanife; Yanikoglu, Berrin; Unal, Gozde

    2010-02-01

    We present a content-based image retrieval system for plant identification which is intended for providing users with a simple method to locate information about their house plants. A plant image consists of a collection of overlapping leaves and possibly flowers, which makes the problem challenging. We studied the suitability of various well-known color, texture and shape features for this problem, as well as introducing some new ones. The features are extracted from the general plant region that is segmented from the background using the max-flow min-cut technique. Results on a database of 132 different plant images show promise (in about 72% of the queries, the correct plant image is retrieved among the top-15 results).

  5. A surface antigen influenza vaccine. 2. Pyrogenicity and antigenicity.

    PubMed Central

    Brady, M. I.; Furminger, I. G.

    1976-01-01

    Conventional influenza vaccine containing whole virus particles purified on a zonal centrifuge is pyrogenic and can cause systemic and local adverse side effects. An improved vaccine was therefore prepared which contained only the surface antigens of the virus adsorbed to aluminium hydroxide. The antigenicity of this vaccine was compared with conventional vaccine in chickens. Both vaccines induced similar titres of serum haemagglutination-inhibition and neuraminidase inhibition antibody. The dose response curves, however, were different. The surface antigens at vaccine strength without aluminium hydroxide were of negligible pyrogenicity in rabbits. PMID:1068196

  6. Effective material parameter retrieval of anisotropic elastic metamaterials with inherent nonlocality

    NASA Astrophysics Data System (ADS)

    Lee, Hyung Jin; Lee, Heung Son; Ma, Pyung Sik; Kim, Yoon Young

    2016-09-01

    In this paper, the scattering (S-) parameter retrieval method is presented specifically for anisotropic elastic metamaterials; so far, no retrieval has been accomplished when elastic metamaterials exhibit fully anisotropic behavior. Complex constitutive property and intrinsic scattering behavior of elastic metamaterials make their characterization far more complicated than that for acoustic and electromagnetic metamaterials. In particular, elastic metamaterials generally exhibit anisotropic scattering behavior due to higher scattering modes associated with shear deformation. They also exhibit nonlocal responses to some degrees, which originate from strong multiple scattering interactions even in the long wavelength limit. Accordingly, the conventional S-parameter retrieval methods cannot be directly used for elastic metamaterials, because they determine only the diagonal components in effective tensor property. Also, the conventional methods simply use the analytic inversion formulae for the material characterization so that inherent nonlocality cannot be taken into account. To establish a retrieval method applicable to anisotropic elastic metamaterials, we propose an alternative S-parameter method to deal with full anisotropy of elastic metamaterials. To retrieve the whole effective anisotropic parameter, we utilize not only normal but also oblique wave incidences. For the retrieval, we first retrieve the ratio of the effective stiffness tensor to effective density and then determine the effective density. The proposed retrieval method is validated by characterizing the effective material parameters of various types of non-resonant anisotropic metamaterials. It is found that the whole effective parameters are retrieved consistently regardless of used retrieval conditions in spite of inherent nonlocality.

  7. Introducing a new method for evaluation of the interaction between an antigen and an antibody: single frequency impedance analysis for biosensing systems.

    PubMed

    Özcan, Burcu; Demirbakan, Burçak; Yeşiller, Gülden; Sezgintürk, Mustafa Kemal

    2014-07-01

    This paper illustrates the application of an antibody, anti-parathyroid hormone (anti-PTH), as a bioreceptor in a biosensor system for the first time, and demonstrates how this biosensor can be used in parathyroid hormone (PTH) determination. The interaction between the biosensor and parathyroid hormone was firstly investigated by a novel electrochemical method, single frequency impedance analysis. The biosensor was based on the gold electrode modified by cysteine self-assembled monolayers. Anti-PTH was covalently immobilized onto cysteine layer by using an EDC/NHS couple. The immobilization of anti-PTH was monitored by cyclic voltammetry and electrochemical impedance spectroscopy techniques. The performance of the biosensor was evaluated in terms of linearity, sensitivity, repeatability and reproducibility, after a few important optimization studies were carried out. In particular, parathyroid hormone was detected within a linear range of 10-60 fg/mL. Kramers-Kronig transform was also performed on the impedance data. The specificity of the biosensor was also evaluated. The biosensor was validated by using a complementary reference technique. Lastly the developed biosensor was used to monitor PTH levels in artificial serum samples.

  8. Visualizing and improving the robustness of phase retrieval algorithms

    SciTech Connect

    Tripathi, Ashish; Leyffer, Sven; Munson, Todd; Wild, Stefan M.

    2015-06-01

    Coherent x-ray diffractive imaging is a novel imaging technique that utilizes phase retrieval and nonlinear optimization methods to image matter at nanometer scales. We explore how the convergence properties of a popular phase retrieval algorithm, Fienup's HIO, behave by introducing a reduced dimensionality problem allowing us to visualize and quantify convergence to local minima and the globally optimal solution. We then introduce generalizations of HIO that improve upon the original algorithm's ability to converge to the globally optimal solution.

  9. Phase Retrieval with Signal Bias. Section 7.3

    NASA Technical Reports Server (NTRS)

    Thurman, Samuel T.; Fienup, James R.

    2009-01-01

    The effect of a uniform measurement bias, due to background light, stray light, detector dark current, or detector offset, on phase retrieval wavefront sensing algorithms is analyzed. Simulation results indicate that the root-mean-square error of the retrieved phase can be more sensitive to an unaccounted-for signal bias than to random noise in practical scenarios. Three methods for reducing the impact of signal bias are presented

  10. [Antigenic response against PPD and antigen 60 in tubercular patients: single antigen versus the combined test].

    PubMed

    Máttar, S; Broquetas, J M; Gea, J; Aran, X; el-Banna, N; Sauleda, J; Torres, J M

    1992-05-01

    We analyze serum samples from 70 patients with pulmonary tuberculosis and 50 healthy individuals. The antigenic activity (IgG) against protein purified antigen (PPD) and antigen 60 (A60) from M. tuberculosis. Thirteen patients were also HIV infected, and three patients had AIDS defined by the presence of disseminated tuberculosis. The test using antigen alone showed a 77% sensitivity and 74% specificity when PPD is used. When A60 was used, both values improved (81% sensitivity, 94% specificity). The use of a combined test (PPD and A60) improves the sensitivity (89%) but reduces the specificity (82%). The HIV infected patients showed similar responses to those of other patients. The combined use of different antigens might be useful for diagnosing tuberculosis. PMID:1390996

  11. Retrieval experience in prospective memory: strategic monitoring and spontaneous retrieval.

    PubMed

    Meier, Beat; Zimmermann, Thomas D; Perrig, Walter J

    2006-10-01

    According to the multi-process model of prospective memory (McDaniel & Einstein, 2000), performance in a prospective memory task may be due to spontaneous retrieval processes or due to strategic monitoring. Spontaneous retrieval is typically accompanied by a pop up experience and strategic monitoring by a search experience. In this study we report two experiments with young adults in which we systematically investigated whether retrieval experience differed across experimental conditions. In Experiment 1 some prospective memory targets were preceded by associated primes. We expected that presenting primes would enhance performance by an automatic activation of the intention and hence lead to an increase in pop up experiences. In Experiment 2 half of the participants received instructions containing information about the specific context in which the prospective memory task would occur, whereas the other half of the participants received no such information. We expected that specific context instructions would enhance performance by legitimate anticipation of the prospective memory task and hence would lead to an increase in search experiences. The results confirmed these expectations. They indicate that the assessment of retrieval experience can provide valuable insights into the processes underlying prospective memory performance. They also suggest that retrieval experience can vary systematically across experimental situations as predicted by the multi-process model.

  12. Serospecific antigens of Legionella pneumophila.

    PubMed Central

    Otten, S; Iyer, S; Johnson, W; Montgomery, R

    1986-01-01

    Serospecific antigens isolated by EDTA extraction from four serogroups of Legionella pneumophila were analyzed for their chemical composition, molecular heterogeneity by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and immunological properties. The antigens were shown to be lipopolysaccharides and to differ from the lipopolysaccharides of other gram-negative bacteria. The serospecific antigens contained rhamnose, mannose, glucosamine, and two unidentified sugars together with 2-keto-3-deoxyoctonate, phosphate, and fatty acids. The fatty acid composition was predominantly branched-chain acids with smaller amounts of 3-hydroxymyristic acid. The antigens contain periodate-sensitive groups; mannosyl residues were completely cleaved by periodate oxidation. Hydrolysis of the total lipopolysaccharide by acetic acid resulted in the separation of a lipid A-like material that cross-reacted with the antiserum to lipid A from Salmonella minnesota but did not comigrate with it on sodium dodecyl sulfate gels. None of the four antigens contained heptose. All of the antigen preparations showed endotoxicity when tested by the Limulus amebocyte lysate assay. The results of this study indicate that the serogroup-specific antigens of L. pneumophila are lipopolysaccharides containing an unusual lipid A and core structure and different from those of other gram-negative bacteria. Images PMID:3017918

  13. Spectral Multimodal Hashing and Its Application to Multimedia Retrieval.

    PubMed

    Zhen, Yi; Gao, Yue; Yeung, Dit-Yan; Zha, Hongyuan; Li, Xuelong

    2016-01-01

    In recent years, multimedia retrieval has sparked much research interest in the multimedia, pattern recognition, and data mining communities. Although some attempts have been made along this direction, performing fast multimodal search at very large scale still remains a major challenge in the area. While hashing-based methods have recently achieved promising successes in speeding-up large-scale similarity search, most existing methods are only designed for uni-modal data, making them unsuitable for multimodal multimedia retrieval. In this paper, we propose a new hashing-based method for fast multimodal multimedia retrieval. The method is based on spectral analysis of the correlation matrix of different modalities. We also develop an efficient algorithm that learns some parameters from the data distribution for obtaining the binary codes. We empirically compare our method with some state-of-the-art methods on two real-world multimedia data sets.

  14. Elaborative Retrieval: Do Semantic Mediators Improve Memory?

    ERIC Educational Resources Information Center

    Lehman, Melissa; Karpicke, Jeffrey D.

    2016-01-01

    The elaborative retrieval account of retrieval-based learning proposes that retrieval enhances retention because the retrieval process produces the generation of semantic mediators that link cues to target information. We tested 2 assumptions that form the basis of this account: that semantic mediators are more likely to be generated during…

  15. Cloud Property Retrieval Products for Graciosa Island, Azores

    DOE Data Explorer

    Dong, Xiquan

    2014-05-05

    The motivation for developing this product was to use the Dong et al. 1998 method to retrieve cloud microphysical properties, such as cloud droplet effective radius, cloud droplets number concentration, and optical thickness. These retrieved properties have been used to validate the satellite retrieval, and evaluate the climate simulations and reanalyses. We had been using this method to retrieve cloud microphysical properties over ARM SGP and NSA sites. We also modified the method for the AMF at Shouxian, China and some IOPs, e.g. ARM IOP at SGP in March, 2000. The ARSCL data from ARM data archive over the SGP and NSA have been used to determine the cloud boundary and cloud phase. For these ARM permanent sites, the ARSCL data was developed based on MMCR measurements, however, there were no data available at the Azores field campaign. We followed the steps to generate this derived product and also include the MPLCMASK cloud retrievals to determine the most accurate cloud boundaries, including the thin cirrus clouds that WACR may under-detect. We use these as input to retrieve the cloud microphysical properties. Due to the different temporal resolutions of the derived cloud boundary heights product and the cloud properties product, we submit them as two separate netcdf files.

  16. A simple method to recover Norovirus from fresh produce with large sample size by using histo-blood group antigen-conjugated to magnetic beads in a recirculating affinity magnetic separation system (RCAMS).

    PubMed

    Tian, Peng; Yang, David; Mandrell, Robert

    2011-06-30

    Human norovirus (NoV) outbreaks are major food safety concerns. The virus has to be concentrated from food samples in order to be detected. PEG precipitation is the most common method to recover the virus. Recently, histo-blood group antigens (HBGA) have been recognized as receptors for human NoV, and have been utilized as an alternative method to concentrate human NoV for samples up to 40 mL in volume. However, to wash off the virus from contaminated fresh food samples, at least 250 mL of wash volume is required. Recirculating affinity magnetic separation system (RCAMS) has been tried by others to concentrate human NoV from large-volume samples and failed to yield consistent results with the standard procedure of 30 min of recirculation at the default flow rate. Our work here demonstrates that proper recirculation time and flow rate are key factors for success in using the RCAMS. The bead recovery rate was increased from 28% to 47%, 67% and 90% when recirculation times were extended from 30 min to 60 min, 120 min and 180 min, respectively. The kinetics study suggests that at least 120 min recirculation is required to obtain a good recovery of NoV. In addition, different binding and elution conditions were compared for releasing NoV from inoculated lettuce. Phosphate-buffered saline (PBS) and water results in similar efficacy for virus release, but the released virus does not bind to RCAMS effectively unless pH was adjusted to acidic. Either citrate-buffered saline (CBS) wash, or water wash followed by CBS adjustment, resulted in an enhanced recovery of virus. We also demonstrated that the standard curve generated from viral RNA extracted from serially-diluted virus samples is more accurate for quantitative analysis than standard curves generated from serially-diluted plasmid DNA or transcribed-RNA templates, both of which tend to overestimate the concentration power. The efficacy of recovery of NoV from produce using RCAMS was directly compared with that of the

  17. Comparable quality attributes of hepatitis E vaccine antigen with and without adjuvant adsorption-dissolution treatment.

    PubMed

    Zhang, Yue; Li, Min; Yang, Fan; Li, Yufang; Zheng, Zizheng; Zhang, Xiao; Lin, Qingshan; Wang, Ying; Li, Shaowei; Xia, Ningshao; Zhang, Jun; Zhao, Qinjian

    2015-01-01

    Most vaccines require adjuvants for antigen stabilization and immune potentiation. Aluminum-based adjuvants are the most widely used adjuvants for human vaccines. Previous reports demonstrated the preservation of antigen conformation and other antigen characteristics after recovery from adjuvanted Hepatitis B and human papillomavirus vaccines. In this study, we used a combination of various physiochemical and immunochemical methods to analyze hepatitis E vaccine antigen quality attributes after recovery from adjuvants. All biochemical and biophysical methods showed similar characteristics of the p239 protein after recovery from adjuvanted vaccine formulation compared to the antigen in solution which never experienced adsorption/desorption process. Most importantly, we demonstrated full preservation of key antigen epitopes post-recovery from adjuvanted vaccine using a panel of murine monoclonal antibodies as exquisite probes. Antigenicity of p239 was probed with a panel of 9 mAbs using competition/blocking ELISA, surface plasmon resonance and sandwich ELISA methods. These multifaceted analyses demonstrated the preservation of antigen key epitopes and comparable protein thermal stability when adsorbed on adjuvants or of the recovered antigen post-dissolution treatment. A better understanding of the antigen conformation in adjuvanted vaccine will enhanced our knowledge of antigen-adjuvant interactions and facilitate an improved process control and development of stable vaccine formulation.

  18. Comparable quality attributes of hepatitis E vaccine antigen with and without adjuvant adsorption-dissolution treatment

    PubMed Central

    Zhang, Yue; Li, Min; Yang, Fan; Li, Yufang; Zheng, Zizheng; Zhang, Xiao; Lin, Qingshan; Wang, Ying; Li, Shaowei; Xia, Ningshao; Zhang, Jun; Zhao, Qinjian

    2015-01-01

    Most vaccines require adjuvants for antigen stabilization and immune potentiation. Aluminum-based adjuvants are the most widely used adjuvants for human vaccines. Previous reports demonstrated the preservation of antigen conformation and other antigen characteristics after recovery from adjuvanted Hepatitis B and human papillomavirus vaccines. In this study, we used a combination of various physiochemical and immunochemical methods to analyze hepatitis E vaccine antigen quality attributes after recovery from adjuvants. All biochemical and biophysical methods showed similar characteristics of the p239 protein after recovery from adjuvanted vaccine formulation compared to the antigen in solution which never experienced adsorption/desorption process. Most importantly, we demonstrated full preservation of key antigen epitopes post-recovery from adjuvanted vaccine using a panel of murine monoclonal antibodies as exquisite probes. Antigenicity of p239 was probed with a panel of 9 mAbs using competition/blocking ELISA, surface plasmon resonance and sandwich ELISA methods. These multifaceted analyses demonstrated the preservation of antigen key epitopes and comparable protein thermal stability when adsorbed on adjuvants or of the recovered antigen post-dissolution treatment. A better understanding of the antigen conformation in adjuvanted vaccine will enhanced our knowledge of antigen-adjuvant interactions and facilitate an improved process control and development of stable vaccine formulation. PMID:26018442

  19. Radiative Transfer and Retrievals in EOF Domain

    NASA Technical Reports Server (NTRS)

    Liu, Xu; Zhou, Daniel K.; Larar, Allen; Smith, William L.; Schluessel, Peter

    2008-01-01

    The Infrared Atmospheric Sounding Interferometer (IASI) is a hyperspectral sensor with 8461 spectral channels and a nominal spectral resolution of 0.25 cm(sup -1). It is computationally intensive to perform radiative transfer calculations and inversions using all these channels. We will present a Principal Component-based Radiative Transfer Model (PCRTM) and a retrieval algorithm which perform all the necessary calculations in EOF domain. Since the EOFs are orthogonal to each other, only about 100 principal components are needed to represent the information content of the 8461 channels. The PCRTM provides the EOF coefficients and associated derivatives with respect to atmospheric and surface parameters needed by the inversion algorithm. The inversion algorithm is based on a non-linear Levenberg-Marquardt method with climatology covariance and a priori information as constraints. The retrieved parameters include atmospheric temperature, moisture and ozone profiles, cloud parameters, surface skin temperature, and surface emissivities. To make the retrieval system even more compact and stable. The atmospheric vertical profiles are compressed into the EOF space as well. The surface emissivities are also compressed into EOF space.

  20. Retrieval Induces Adaptive Forgetting of Competing Memories via Cortical Pattern Suppression

    PubMed Central

    Wimber, Maria; Alink, Arjen; Charest, Ian; Kriegeskorte, Nikolaus; Anderson, Michael C.

    2015-01-01

    Remembering a past experience can, surprisingly, cause forgetting. Forgetting arises when other competing traces interfere with retrieval, and inhibitory control mechanisms are engaged to suppress the distraction they cause. This form of forgetting is considered adaptive because it reduces future interference. The impact of this proposed inhibition process on competing memories has, however, never been observed both because behavioural methods are “blind” to retrieval dynamics and because neuroimaging methods have not isolated retrieval of individual memories. Here we introduce a canonical template tracking method to quantify the activation state of individual target memories and competitors during retrieval. This method revealed that repeatedly retrieving target memories suppressed cortical patterns unique to competitors. Pattern suppression was related to engagement of prefrontal regions implicated in resolving retrieval competition, and, critically, predicted later forgetting. We thus demonstrate a cortical pattern suppression mechanism through which remembering adaptively shapes which aspects of our past remain accessible. PMID:25774450