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Sample records for antigen retrieval methods

  1. A 2-Step Laemmli and Antigen Retrieval Method Improves Immunodetection.

    PubMed

    Scalia, Carla R; Gendusa, Rossella; Cattoretti, Giorgio

    2016-07-01

    Detection by immunohistochemistry of antigens relies on reproducibly optimal preanalytical and analytical variables such as fixation conditions, antigen retrieval (AR), and the resolutive power of the detection system. There is a need to improve immunodetection on routinely fixed and embedded material, particularly for scarcely represented but relevant antigens. We devised a 2-step method and applied it to a panel of antigens of common use for diagnosis, prognosis, individualized therapy use, or research. The first step consists of a 10 minutes. Incubation at 95°C with a modified Laemmli extraction buffer. This was followed by a traditional AR method. Detection of the vast majority of antigens was improved over a simple AR with preservation of tissue integrity, as shown by quantitative image analysis. The mechanism underlying the improved detection may be controlled denaturation followed by heat-mediated retrieval, a method we dubbed "antigen relaxing" and which will improve routine detection of scarce antigens in formalin-fixed, paraffin-embedded material. PMID:26067142

  2. A simple and effective heat induced antigen retrieval method

    PubMed Central

    K.R., Vinod; Jones, Denny; Udupa, Venkatesha

    2016-01-01

    In this paper, we describe an additional step to the standard method of heat induced antigen retrieval to improve the detection of antibody staining of formalin fixed paraffin embedded tissue sections. Direct heating of tissues in buffer is an efficient epitope retrieval method but often results in the damage or loss of tissues. In this modified method, before keeping in buffer for heating, we overlapped the tissue on the slide with a plain slide by clipping one end using a normal paperclip, keeping a minimum gap between the slides. Tissues heated in this way in buffer had following advantages over normal heat treatment for epitope retrieval. • Tissues were intact even at high temperatures which improved the quality of staining by preventing fold, damage or detachment of tissues from the slides. • The method is very safe and economical compared to the methods using microwave or pressure cooker. • This simple method also appears to be very effective and less time consuming compared to the existing methods. PMID:27158596

  3. 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

  4. 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

  5. Functional TCR retrieval from single antigen-specific human T cells reveals multiple novel epitopes.

    PubMed

    Simon, Petra; Omokoko, Tana A; Breitkreuz, Andrea; Hebich, Lisa; Kreiter, Sebastian; Attig, Sebastian; Konur, Abdo; Britten, Cedrik M; Paret, Claudia; Dhaene, Karl; Türeci, Özlem; Sahin, Ugur

    2014-12-01

    The determination of the epitope specificity of disease-associated T-cell responses is relevant for the development of biomarkers and targeted immunotherapies against cancer, autoimmune, and infectious diseases. The lack of known T-cell epitopes and corresponding T-cell receptors (TCR) for novel antigens hinders the efficient development and monitoring of new therapies. We developed an integrated approach for the systematic retrieval and functional characterization of TCRs from single antigen-reactive T cells that includes the identification of epitope specificity. This is accomplished through the rapid cloning of full-length TCR-α and TCR-β chains directly from single antigen-specific CD8(+) or CD4(+) T lymphocytes. The functional validation of cloned TCRs is conducted using in vitro-transcribed RNA transfer for expression of TCRs in T cells and HLA molecules in antigen-presenting cells. This method avoids the work and bias associated with repetitive cycles of in vitro T-cell stimulation, and enables fast characterization of antigen-specific T-cell responses. We applied this strategy to viral and tumor-associated antigens (TAA), resulting in the retrieval of 56 unique functional antigen-specific TCRs from human CD8(+) and CD4(+) T cells (13 specific for CMV-pp65, 16 specific for the well-known TAA NY-ESO-1, and 27 for the novel TAA TPTE), which are directed against 39 different epitopes. The proof-of-concept studies with TAAs NY-ESO-1 and TPTE revealed multiple novel TCR specificities. Our approach enables the rational development of immunotherapy strategies by providing antigen-specific TCRs and immunogenic epitopes. PMID:25245536

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. 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

  11. Application of Probabilistic Methods to Chinese Text Retrieval.

    ERIC Educational Resources Information Center

    Huang, Xiangji; Robertson, S. E.

    1997-01-01

    Discusses the use of text retrieval methods based on probabilistic models with Chinese language material, which are modeled on the Okapi information retrieval system. Topics include system architecture, test collections, weighting functions, and algorithms. (Author/LRW)

  12. Advanced Feedback Methods in Information Retrieval.

    ERIC Educational Resources Information Center

    Salton, G.; And Others

    1985-01-01

    In this study, automatic feedback techniques are applied to Boolean query statements in online information retrieval to generate improved query statements based on information contained in previously retrieved documents. Feedback operations are carried out using conventional Boolean logic and extended logic. Experimental output is included to…

  13. Patterns of MiB-1 staining of brain tumors: microwave-antigen retrieval as a tool in diagnostic pathology.

    PubMed

    Meera, G; Jo, H; Ravi, R

    1995-11-01

    MiB-1 antibody staining can be carried out on formalin fixed, paraffin embedded tissue only if microwave antigen retrieval is performed. This method was used to identify proliferating cells in archival paraffin sections of 137 cases of human brain tumors. The tumors concerned were astrocytomas (57), glioblastomas (16), oligodendrogliomas (11), mixed gliomas (8), ependymomas (9), subependymoma (2), medulloblastomas (4) and meningiomas (30). For the tumors which were histologically graded (the astrocytomas, oligodendrogliomas and ependymomas), generally the scores of MiB-1 staining were correlated with the tumor grade, although there were exceptions to this rule, for example, a few low grade tumors displayed high MiB-1 counts while some highly malignant brain tumors failed to display any positive staining for MiB-1, despite having high mitotic counts. This phenomenon was probably due to loss of proliferating antigens. In the MiB-1 positive sections, hot spots with a high mitotic activity could be identified with ease and the abnormal morphology of the tumor nuclei and of the atypical mitoses were highlighted by the contrasting intensily brown staining. In addition, the dividing cell type could be easily identified and differences in mitotic behavior of invasive and necrotic parts of tumors could be observed. PMID:8835134

  14. A robust general phase retrieval method for medical applications

    PubMed Central

    Yan, A.; Liu, H.

    2013-01-01

    From medical imaging perspective the robustness of a phase retrieval method is of critical importance. In this presentation we compare the robustness of two general phase retrieval methods, namely the transport of intensity equation inversion (TIE-inversion) method and the attenuation partition based (AP-based) method. We showed that the TIE-inversion method, regardless if being assisted with the Tikhonov regularization, failed to retrieve the phase maps in two experimental studies. The failure exposes this method’s weakness as being unstable against the noise. In contrast, the sample phase maps are retrieved successfully by using the AP-based method. The stark performance differences of the two methods are rooted in their different techniques dealing with the singularity problem. This comparison shows that the robust AP-based phase retrieval method will be superior to the TIE-inversion method for medical imaging applications where radiation doses are stringently limited. PMID:23894250

  15. 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.

  16. Retrieval of functional TCRs from single antigen-specific T cells: Toward individualized TCR-engineered therapies

    PubMed Central

    Omokoko, Tana; Simon, Petra; Türeci, Özlem; Sahin, Ugur

    2015-01-01

    We have developed a highly versatile platform for the systematic retrieval of T-cell receptors (TCRs) from single-antigen-reactive T cells and for characterization of their function and specificity. This approach enables rapid extraction of multiple TCRs from repertoires in individuals and not only broadens the diversity of TCRs suitable for clinical use, but also sets the stage for actively personalized immunotherapeutic strategies. PMID:26140230

  17. Infrared Retrievals of Ice Cloud Properties and Uncertainties with an Optimal Estimation Retrieval Method

    NASA Astrophysics Data System (ADS)

    Wang, C.; Platnick, S. E.; Meyer, K.; Zhang, Z.

    2014-12-01

    We developed an optimal estimation (OE)-based method using infrared (IR) observations to retrieve ice cloud optical thickness (COT), cloud effective radius (CER), and cloud top height (CTH) simultaneously. The OE-based retrieval is coupled with a fast IR radiative transfer model (RTM) that simulates observations of different sensors, and corresponding Jacobians in cloudy atmospheres. Ice cloud optical properties are calculated using the MODIS Collection 6 (C6) ice crystal habit (severely roughened hexagonal column aggregates). The OE-based method can be applied to various IR space-borne and airborne sensors, such as the Moderate Resolution Imaging Spectroradiometer (MODIS) and the enhanced MODIS Airborne Simulator (eMAS), by optimally selecting IR bands with high information content. Four major error sources (i.e., the measurement error, fast RTM error, model input error, and pre-assumed ice crystal habit error) are taken into account in our OE retrieval method. We show that measurement error and fast RTM error have little impact on cloud retrievals, whereas errors from the model input and pre-assumed ice crystal habit significantly increase retrieval uncertainties when the cloud is optically thin. Comparisons between the OE-retrieved ice cloud properties and other operational cloud products (e.g., the MODIS C6 and CALIOP cloud products) are shown.

  18. 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.

  19. Antigen

    MedlinePlus

    An antigen is any substance that causes your immune system to produce antibodies against it. This means your immune ... and is trying to fight it off. An antigen may be a substance from the environment, such ...

  20. The immunohistochemical detection of mismatch repair gene proteins (MLH1, MSH2, MSH6, and PMS2): practical aspects in antigen retrieval and biotin blocking protocols.

    PubMed

    Manavis, Jim; Gilham, Peter; Davies, Ruth; Ruszkiewicz, Andrew

    2003-03-01

    The immunohistochemical detection of the mismatch repair (MMR) proteins is used as a screening test with microsatellite instability for the detection of hereditary nonpolyposis colon cancer (HNPCC). The authors describe a simple and cost-effective method using a pressure cooker and microwave oven for antigen retrieval and a modified method for applying a commercial biotin blocking kit. Colorectal tumors of 20 patients of the HNPCC spectrum were included in this study. Eighty paraffin sections were cut and submitted for immunohistochemical analysis using a routine protocol and a pressure cooker protocol. Parallel sections for biotin blocking were also run, including the modified biotin block for each protocol. The sections were incubated with the following antibodies: MLH1, MSH2, MSH6, and PMS2. All cases examined exhibited a normal expression of the MMR proteins in the nucleus and adjacent nonneoplastic tissue elements and consequently defined as having a normal expression of these proteins. Cases with tumor that exhibited a loss of the nuclear staining with the MMR proteins with a concurrent staining of the adjacent nonneoplastic cells were classified as abnormal MMR expression. The series of 20 cases using pressure cooker antigen retrieval produced superior results to the routine immunohistochemical protocol used previously in our laboratory. The modified biotin block also gave consistent results. The reproducibility and consistency of this procedure has resulted it in being used routinely for suspected HNPCC cases, both current and archival. PMID:12610360

  1. 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. PMID:22984898

  2. 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

  3. 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

  4. Detection of peste des petits ruminants virus antigen using immunofiltration and antigen-competition ELISA methods.

    PubMed

    Raj, G Dhinakar; Rajanathan, T M C; Kumar, C Senthil; Ramathilagam, G; Hiremath, Geetha; Shaila, M S

    2008-06-22

    Peste des petits ruminants (PPR) is one of the most economically important diseases affecting sheep and goats in India. An immunofiltration-based test has been developed using either mono-specific serum/monoclonal antibodies (mAb) prepared against a recombinant truncated nucleocapsid protein of rinderpest virus (RPV) cross-reactive with PPR virus. This method consists of coating ocular swab eluate from suspected animals onto a nitrocellulose membrane housed in a plastic module, which is allowed to react with suitable dilutions of a mAb or a mono-specific polyclonal antibody. The antigen-antibody complex formed on the membrane is then detected by protein A-colloidal gold conjugate, which forms a pink colour. In the immunofiltration test, concordant results were obtained using either PPRV mAb or mono-specific serum. Another test, an antigen-competition ELISA which relies on the competition between plate-coated recombinant truncated 'N' protein of RPV and the PPRV 'N' protein present in ocular swab eluates (sample) for binding to the mono-specific antibody against N protein of RPV (in liquid phase) was developed. The cut-off value for this test was established using reverse transcription polymerase chain reaction (RT-PCR) positive and negative oculo-nasal swab samples. Linear correlation between percent inhibition (PI) values in antigen-competition ELISA and virus infectivity titres was 0.992. Comparison of the immunofiltration test with the antigen-competition ELISA yielded a sensitivity of 80% and specificity of 100%. These two tests can serve as a screening (immunofiltration) and confirmatory (antigen-competition ELISA) test, respectively, in the diagnosis of PPR in sheep or goats. PMID:18182256

  5. High-resolution methods for fluorescence retrieval from space.

    PubMed

    Mazzoni, Marina; Falorni, Pierluigi; Verhoef, Wouter

    2010-07-19

    The retrieval from space of a very weak fluorescence signal was studied in the O(2)A and O(2)B oxygen atmospheric absorption bands. The accuracy of the method was tested for the retrieval of the chlorophyll fluorescence and reflectance terms contributing to the sensor signal. The radiance at the top of the atmosphere was simulated by means of a commercial radiative-transfer program at a high resolution (0.1 cm(-1)). A test data set was generated in order to simulate sun-induced chlorophyll fluorescence at the top of the canopy. Reflectance terms were spectrally modeled using cubic splines and fluorescence by means of the sum of two Voigt functions. Sensor radiance residual minimization was performed in the presence of a multiplicative noise, thus ensuring that the sensor simulations were realistic. The study, which focused on the possibility of retrieving fluorescence with an accuracy better than 10%, was performed for instrument resolutions ranging from about 0.4 cm(-1) to 2 cm(-1) in order to test the algorithm for the characteristics of existing and planned hyper-spectral sensors. The algorithm was also used to retrieve fluorescence in the single O(2)A band at the OCO and TANSO-FTS instrument spectral resolutions. PMID:20720947

  6. Phase retrieval-based distribution detecting method for transparent objects

    NASA Astrophysics Data System (ADS)

    Wu, Liang; Tao, Shaohua; Xiao, Si

    2015-11-01

    A distribution detecting method to recover the distribution of transparent objects from their diffraction intensities is proposed. First, on the basis of the Gerchberg-Saxton algorithm, a wavefront function involving the phase change of the object is retrieved from the incident light intensity and the diffraction intensity, then the phase change of the object is calculated from the retrieved wavefront function by using a gradient field-based phase estimation algorithm, which circumvents the common phase wrapping problem. Finally, a linear model between the distribution of the object and the phase change is set up, and the distribution of the object can be calculated from the obtained phase change. The effectiveness of the proposed method is verified with simulations and experiments.

  7. 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.

  8. 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

  9. Incremental learning methods with retrieving of interfered patterns.

    PubMed

    Yamauchi, K; Yamaguchi, N; Ishii, N

    1999-01-01

    There are many cases that a neural-network-based system must memorize some new patterns incrementally. However, if the network learns the new patterns only by referring to them, it probably forgets old memorized patterns, since parameters in the network usually correlate not only to the old memories but also to the new patterns. A certain way to avoid the loss of memories is to learn the new patterns with all memorized patterns. It needs, however, a large computational power. To solve this problem, we propose incremental learning methods with retrieving interfered patterns (ILRI). In these methods, the system employs a modified version of a resource allocating network (RAN) which is one variation of a generalized radial basis function (GRBF). In ILRI, the RAN learns new patterns with a relearning of a few number of retrieved past patterns that are interfered with the incremental learning. In this paper, we construct ILRI in two steps. In the first step, we construct a system which searches the interfered patterns from past input patterns stored in a database. In the second step, we improve the first system in such a way that the system does not need the database. In this case, the system regenerates the input patterns approximately in a random manner. The simulation results show that these two systems have almost the same ability, and the generalization ability is higher than other similar systems using neural networks and k-nearest neighbors. PMID:18252636

  10. Identification of 5-bromo-2'-deoxyuridine-labeled cells during mouse spermatogenesis by heat-induced antigen retrieval in lectin staining and immunohistochemistry.

    PubMed

    Wakayama, Tomohiko; Nakata, Hiroki; Kumchantuek, Tewarat; Gewaily, Mahmoud Saad; Iseki, Shoichi

    2015-03-01

    DNA replication occurs during S-phase in spermatogonia and preleptotene spermatocytes during spermatogenesis. 5-Bromo-2'-deoxyuridine (BrdU) is incorporated into synthesized DNA and is detectable in the nucleus by immunohistochemistry (IHC). To identify BrdU-labeled spermatogenic cells, the spermatogenic stages must be determined by visualizing acrosomes and detecting cell type-specific marker molecules in the seminiferous tubules. However, the antibody reaction with BrdU routinely requires denaturation of the DNA, which is achieved by pretreating tissue sections with hydrochloric acid; however, this commonly interferes with further histochemical approaches. Therefore, we examined optimal methods for pretreating paraffin sections of the mouse testis to detect incorporated BrdU by an antibody and, at the same time, visualize acrosomes with peanut agglutinin (PNA) or detect several marker molecules with antibodies. We found that the use of heat-induced antigen retrieval (HIAR), which consisted of heating at 95C in 20 mM Tris-HCl buffer (pH 9.0) for 15 min, was superior to the use of 2 N hydrochloric acid for 90 min at room temperature in terms of the quality of subsequent PNA-lectin histochemistry with double IHC for BrdU and an appropriate stage marker protein. With this method, we identified BrdU-labeled spermatogenic cells during mouse spermatogenesis as A1 spermatogonia through to preleptotene spermatocytes. PMID:25479790

  11. 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)

  12. Robustness of phase retrieval methods in x-ray phase contrast imaging: A comparison

    SciTech Connect

    Yan, Aimin; Wu, Xizeng; Liu, Hong

    2011-09-15

    Purpose: The robustness of the phase retrieval methods is of critical importance for limiting and reducing radiation doses involved in x-ray phase contrast imaging. This work is to compare the robustness of two phase retrieval methods by analyzing the phase maps retrieved from the experimental images of a phantom. Methods: Two phase retrieval methods were compared. One method is based on the transport of intensity equation (TIE) for phase contrast projections, and the TIE-based method is the most commonly used method for phase retrieval in the literature. The other is the recently developed attenuation-partition based (AP-based) phase retrieval method. The authors applied these two methods to experimental projection images of an air-bubble wrap phantom for retrieving the phase map of the bubble wrap. The retrieved phase maps obtained by using the two methods are compared. Results: In the wrap's phase map retrieved by using the TIE-based method, no bubble is recognizable, hence, this method failed completely for phase retrieval from these bubble wrap images. Even with the help of the Tikhonov regularization, the bubbles are still hardly visible and buried in the cluttered background in the retrieved phase map. The retrieved phase values with this method are grossly erroneous. In contrast, in the wrap's phase map retrieved by using the AP-based method, the bubbles are clearly recovered. The retrieved phase values with the AP-based method are reasonably close to the estimate based on the thickness-based measurement. The authors traced these stark performance differences of the two methods to their different techniques employed to deal with the singularity problem involved in the phase retrievals. Conclusions: This comparison shows that the conventional TIE-based phase retrieval method, regardless if Tikhonov regularization is used or not, is unstable against the noise in the wrap's projection images, while the AP-based phase retrieval method is shown in these

  13. Carcinoembryonic antigen continuous epitopes determined by the spot method.

    PubMed

    Solassol, I; Granier, C; Pèlegrin, A

    2001-01-01

    Carcinoembryonic antigen (CEA) is a heavily glycosylated tumor-associated protein with an N-A1-B1-A2-B2-A3-B3 domain structure. Circulating CEA immunoassays are used for monitoring digestive cancer patients, and radiolabeled anti-CEA monoclonal antibodies (MAb) are used for the diagnosis and therapy of CEA-positive tumors. The five major nonoverlapping epitopes (Gold 1-5) have been broadly correlated with the domain organization, but there is no precise localization of the epitopes at the sequence level. In an attempt to identify the peptide sequences corresponding to the five Gold epitopes on the CEA molecule, we prepared a set of 227 overlapping fifteen-mer peptides corresponding to the complete CEA sequence with the SPOT method. Using five high affinity MAbs directed against the five CEA Gold epitopes, we demonstrated that none of these epitopes could be mimicked by a fifteen-mer peptide sequence. However, using rabbit and goat anti-CEA sera, we identified six major continuous antigenic regions. All are included in the Ig-like domains of the CEA: two in the A1 domain (residues 120-134 and 153-164), one each in the A2 (329-337) and A3 domains (508-513), one at the junction between the A3 and B3 domains (553-561) and one in the B3 domain (565-573). A very homologous sequence (common residues VSPRL) was mapped in each of the three A domains. Thus, in terms of occurrence of continuous epitopes, the Ig-like domains A1, A2, A3 and B3 seem to be the most antigenic parts of CEA. These peptide sequences should be good candidates for the future development of site-specific anti-CEA MAbs. PMID:11275797

  14. Bacterial antigen detection in body fluids: methods for rapid antigen concentration and reduction of nonspecific reactions.

    PubMed Central

    Doskeland, S O; Berdal, B P

    1980-01-01

    We sought procedures which would allow a rapid concentration in high yield of bacterial antigens from tissue fluids of patients and which could be applied also to protein-rich fluids like serum. Ethanol precipitation at a subzero temperature with albumin added as an antigen coprecipitant made it possible to achieve a more than 20-fold concentration of antigen in 15 min and a 200-fold concentration in 45 min. Heat-stable antigens could be concentrated from protein-rich fluids (like serum) after the sample had been deproteinized by boiling. Such heating (100 degrees C, 3 min) also liberated bacterial polysaccharides from antibody complexes and elminated the nonspecific interference of serum in enzyme-linked immunosorbent assay. PMID:7372801

  15. Intelligent Interfaces and Retrieval Methods for Subject Searching in Bibliographic Retrieval Systems.

    ERIC Educational Resources Information Center

    Hildreth, Charles R.

    This study was designed to be a state-of-the-art survey and investigation of intelligent "front end" design approaches and software for improving subject access and subject searching in today's large online bibliographic retrieval systems and online public access catalogs (OPACS). The report begins with an illustrated overview of retrieval…

  16. 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.

    PubMed

    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. PMID:15817147

  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. 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. PMID:15818860

  19. An Improvement Method for Online Response of BBS Articles Retrieval with Users Evaluation

    NASA Astrophysics Data System (ADS)

    Morita, Yoshihiro; Akiyoshi, Masanori; Komoda, Norihisa

    Recently, BBS (Bulletin Board System) has been frequently used to exchange users' opinions on the Internet. An efficient retrieval method that uses past other users' evaluation has been proposed to retrieve target information efficiently and correctly. In this method, it is necessary to cluster past queries to calculate accurately thread score. However, this method has defect from practical points of views, because the time for clustering is so long that an user feels stress. Therefore, we proposed an improvement method which utilizes past clustering result for online response of BBS articles retrieval with users evaluation. Through an experiment, the accuracy of retrieval was almost same as compared with the conventional method, and the average time for retrieval reduced from 25.4 seconds to 3.1 on average using 890 threads.

  20. A Method for Retrieving Ground Flash Fraction from Satellite Lightning Imager Data

    NASA Technical Reports Server (NTRS)

    Koshak, William J.

    2009-01-01

    A general theory for retrieving the fraction of ground flashes in N lightning observed by a satellite-based lightning imager is provided. An "exponential model" is applied as a physically reasonable constraint to describe the measured optical parameter distributions, and population statistics (i.e., mean, variance) are invoked to add additional constraints to the retrieval process. The retrieval itself is expressed in terms of a Bayesian inference, and the Maximum A Posteriori (MAP) solution is obtained. The approach is tested by performing simulated retrievals, and retrieval error statistics are provided. The ability to retrieve ground flash fraction has important benefits to the atmospheric chemistry community. For example, using the method to partition the existing satellite global lightning climatology into separate ground and cloud flash climatologies will improve estimates of lightning nitrogen oxides (NOx) production; this in turn will improve both regional air quality and global chemistry/climate model predictions.

  1. Method to conjugate polysaccharide antigens to surfaces for the detection of antibodies.

    PubMed

    Boas, Ulrik; Lind, Peter; Riber, Ulla

    2014-11-15

    A new generic method for the conjugation of lipopolysaccharide (LPS)-derived polysaccharide antigens from gram-negative bacteria has been developed using Salmonella as a model. After removal of lipid A from the LPS by mild acidolysis, the polysaccharide antigen was conjugated to polystyrene microbeads modified with N-alkyl hydroxylamine and N-alkyl-O-methyl hydroxylamine surface groups by incubation of antigen and beads for 16 h at 40 °C without the need for coupling agents. The efficiency of the new method was evaluated by flow cytometry in model samples and serum samples containing antibodies against Salmonella typhimurium and Salmonella dublin. The presented method was compared with a similar method for conjugation of Salmonella polysaccharide antigens to surfaces. Here, the new method showed higher antigen coupling efficiency by detecting low concentrations of antibodies. Furthermore, the polysaccharide-conjugated beads showed preserved bioactivity after 1 year of use. PMID:25076184

  2. 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.

  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

    2015-11-01

    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. Purification of intracellular compartments involved in antigen processing: a new method based on magnetic sorting.

    PubMed Central

    Perrin-Cocon, L A; Marche, P N; Villiers, C L

    1999-01-01

    In the present study, we describe a method to specifically isolate intracellular compartments containing endocytosed antigen. We have demonstrated that isolated compartments represent a small proportion of the intracellular material, highly enriched in antigen. Antigen-containing vesicles are specifically sorted from other intracellular compartments, such as endoplasmic reticulum or Golgi apparatus, and from the plasma membrane. They remain functional in vitro since they can be acidified, and the antigen inside has been found to be partially proteolysed. In macrophages, kinetic analysis has revealed that the antigen is first found in compartments of endosomal density, carrying Rab 5 and Rab 7, then in late compartments of lysosomal density, which are rich in proteases. The global protein content of the compartments was mapped by two-dimensional electrophoresis. In B lymphocytes, this method has allowed the isolation of endocytic compartments emerging from receptor-mediated endocytosis of the antigen. After 2 h of chase, the antigen reached vesicles containing large amounts of MHC-class II molecules, invariant chain and human leucocyte antigen-DM, where peptide loading can occur. PMID:9931307

  5. 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

  6. 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

  7. A new multispectral cloud retrieval method for ship-based solar transmissivity measurements

    NASA Astrophysics Data System (ADS)

    Brückner, M.; Pospichal, B.; Macke, A.; Wendisch, M.

    2014-10-01

    Within the German Leibniz-network OCEANET project, ship-based lidar and microwave remote sensing as well as spectral zenith radiance observations with the COmpact RAdiation measurements System (CORAS) were performed. During three cruises latitudes between 50°N and 50°S were covered. A new spectral retrieval method to derive the cloud optical thickness τ and the droplet effective radius reff using CORAS measurements is developed. The method matches CORAS measurements of ratios of spectral transmissivity at six wavelengths with modeled transmissivities. This retrieval is fast and accurate and thus suitable for operational purposes. The new approach circumvents ambiguities of existing cloud retrievals and reduces the influence of measurement uncertainties. It is applied to homogenous and heterogeneous liquid water and cirrus clouds. In boundary layer liquid water clouds, the retrieved effective radius was more variable, whereas in the cirrus it was rather constant. Furthermore, the liquid water path LWP was derived and compared to data from a microwave radiometer. The new retrieval tends to overestimate LWP for thick liquid water clouds but slightly underestimate LWP for thin clouds. The presented method cannot be applied to mixed-phase clouds. The maximum retrieval of τ and reff for liquid water clouds is 80 in τ and 30 μm in reff, respectively; for cirrus clouds the limitations of the retrieval are 10 in τ and 60 μm in reff.

  8. Performance analysis of quantitative phase retrieval method in Zernike phase contrast X-ray microscopy

    NASA Astrophysics Data System (ADS)

    Heng, Chen; Kun, Gao; Da-Jiang, Wang; Li, Song; Zhi-Li, Wang

    2016-02-01

    Since the invention of Zernike phase contrast method in 1930, it has been widely used in optical microscopy and more recently in X-ray microscopy. Considering the image contrast is a mixture of absorption and phase information, we recently have proposed and demonstrated a method for quantitative phase retrieval in Zernike phase contrast X-ray microscopy. In this contribution, we analyze the performance of this method at different photon energies. Intensity images of PMMA samples are simulated at 2.5 keV and 6.2 keV, respectively, and phase retrieval is performed using the proposed method. The results demonstrate that the proposed phase retrieval method is applicable over a wide energy range. For weakly absorbing features, the optimal photon energy is 2.5 keV, from the point of view of image contrast and accuracy of phase retrieval. On the other hand, in the case of strong absorption objects, a higher photon energy is preferred to reduce the error of phase retrieval. These results can be used as guidelines to perform quantitative phase retrieval in Zernike phase contrast X-ray microscopy with the proposed method. Supported by the State Key Project for Fundamental Research (2012CB825801), National Natural Science Foundation of China (11475170, 11205157 and 11179004) and Anhui Provincial Natural Science Foundation (1508085MA20).

  9. Aerosol and trace gas profile retrievals from MAX-DOAS observations using simple least squares methods

    NASA Astrophysics Data System (ADS)

    Wagner, Thomas; Beirles, Steffen; Shaiganfar, Reza

    2010-05-01

    Multi-AXis (MAX-) DOAS observations have become a widely used technique for the retrieval of atmospheric profiles of trace gases and aerosols. Since the information content of MAX-DOAS observations is limited, usually optimal estimation techniques are used for profile inversion, and a-priori assumptions are needed. In contrast, in our retrieval we limit the retrieved parameter to few basic profile parameters (e.g. profile shape and integrated column density), which are retrieved without further a-priori assumptions. The retrieval is instead based on simple least squares methods. Despite the simple retrieval scheme, our method has the advantage that it is very robust and stable. It also yields the most important parameters with good accuracy (e.g. total aerosol optical depth, total tropospheric trace gas column density, surface aerosol extinction, surface trace gas mixing ratio). Some of these parameters can even be retrieved for cloudy conditions. We present MAX-DOAS results from two measurement campaigns: The CINDI campaign in Cabauw, The Netherlands, in 2009 and the FORMAT campaign in Milano, Italy, in 2003. Results for aerosols, NO2, and HCHO, are presented and compared to independent measurements.

  10. 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

  11. 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.

  12. 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.

  13. A benchmark system for the evaluation of selected phase retrieval methods

    NASA Astrophysics Data System (ADS)

    Lingel, Christian; Hasler, Malte; Haist, Tobias; Pedrini, Giancarlo; Osten, Wolfgang

    2014-05-01

    In comparison to classical phase measurement methods like interferometry and holography, there are many phase retrieval methods which are able to recover the phase of a complex valued object without the necessity of a reference wave. Due to the large number of different methods, iterative as well as non-iterative ones, it is hard to find the method which is appropriate for a given application or object. We propose a system which is based on different criteria, some of which can be calculated by analyzing the phase retrieval result compared to the original object. Other criteria like the complexity of the optical system are also taken into account. For testing the benchmark system we use a software which is suitable, first, to simulate the acquisition process of the intensity measurements, second, to run the phase retrieval algorithm itself and, third, to calculate the values of the benchmark criteria. Having determined the values of the different criteria we assign points for every criterion which can be weighted by importance and are summed up for getting an overall benchmark score. This final score can be used to compare different phase retrieval methods and by having a closer look at the single criteria it is possible to analyze the strengths and weaknesses of the method. We will show the detailed proceeding of calculating the benchmark value by means of a selected phase retrieval method and a phase only object (USAF target). We have to emphasize that the results strongly depend on the object.

  14. 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.

  15. Evaluation of Semantic-Based Information Retrieval Methods in the Autism Phenotype Domain

    PubMed Central

    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. PMID:22195112

  16. 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. PMID:22195112

  17. Retrieval of Temperature From a Multiple Channel Rayleigh-Scatter Lidar Using an Optimal Estimation Method

    NASA Astrophysics Data System (ADS)

    Sica, R. J.; Haefele, A.

    2014-12-01

    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 temperature have several shortcoming which can be overcome using an optimal estimation method (OEM). OEMs are applied to the retrieval of temperature from Rayleigh-scatter lidar measurements using both single and multiple channel measurements. Forward models are presented that completely characterize the measurement and allow the simultaneous retrieval of temperature, dead time and background. The method 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. This demonstrated success of lidar temperature retrievals using an OEM opens new possibilities in atmospheric science for measurement integration between active and passive remote sensing instruments. We are currently working on extending our method to simultaneously retrieve water vapour and temperature using Raman-scatter lidar measurements.

  18. 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.

  19. 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.

  20. Evaluation of a content-based retrieval system for blood cell images with automated methods.

    PubMed

    Seng, Woo Chaw; Mirisaee, Seyed Hadi

    2011-08-01

    Content-based image retrieval techniques have been extensively studied for the past few years. With the growth of digital medical image databases, the demand for content-based analysis and retrieval tools has been increasing remarkably. Blood cell image is a key diagnostic tool for hematologists. An automated system that can retrieved relevant blood cell images correctly and efficiently would save the effort and time of hematologists. The purpose of this work is to develop such a content-based image retrieval system. Global color histogram and wavelet-based methods are used in the prototype. The system allows users to search by providing a query image and select one of four implemented methods. The obtained results demonstrate the proposed extended query refinement has the potential to capture a user's high level query and perception subjectivity by dynamically giving better query combinations. Color-based methods performed better than wavelet-based methods with regard to precision, recall rate and retrieval time. Shape and density of blood cells are suggested as measurements for future improvement. The system developed is useful for undergraduate education. PMID:20703533

  1. A Method to Retrieve Rainfall Rate over Land from TRMM Observations

    NASA Technical Reports Server (NTRS)

    Prabhakara, C.; Iacovazzi, R., Jr.; Yoo, J.-M.

    2002-01-01

    Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) observations over mesoscale convective systems (MCSs) reveal that there are localized maxima in the rain rate with a scale of about 10 to 20 km that represent thunderstorms (Cbs). Some of these Cbs are developing or intense, while others are decaying or weak. These Cbs constitute only about 20 % of the rain area of a given MCS. Outside of Cbs, the average rain rate is much weaker than that within Cbs. From an analysis of the PR data, we find that the spatial distribution of rain and its character, convective or stratiform, is highly inhomogeneous. This complex nature of rain exists on a scale comparable to that of a Cb. The 85 GHz brightness temperature, T85, observations of the TRMM Microwave Imager (TMI) radiometer taken over an MCS reflect closely the PR rain rate pattern over land. Local maxima in rain rate shown by PR are observed as local minima in T85. Where there are no minima in T85, PR observations indicate there is light rain. However, the TMI brightness temperature measurements (Tbs) have poor ability to discriminate convective rain from stratiform rain. For this reason, a TMI rain retrieval procedure that depends primarily on the magnitude of Tbs performs poorly. In order to retrieve rain rate from TMI data on land one has to include the spatial distribution information deduced from the T85 data in the retrieval method. Then, quantitative estimation of rain rate can be accomplished. A TMI rain retrieval method developed along these lines can yield estimates of rain rate and its frequency distribution which agree closely with that given by PR. We find the current TRMM project TMI (Version 5) rain retrieval algorithm on land could be improved with the retrieval scheme developed here. To support the conceptual frame work of the rain retrieval method developed here, a theoretical analysis of the TMI brightness temperatures in convective and stratiform regions is presented.

  2. 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

  3. 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)

  4. 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…

  5. 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.

  6. Investigation of Cryptosporidium spp. antigen by ELISA method in stool specimens obtained from patients with diarrhea.

    PubMed

    Elgun, Gullu; Koltas, Ismail Soner

    2011-02-01

    Cryptosporidium spp. is an important parasitic protozoan causing diarrhea in developing and developed countries. The agent causes severe life-threatening diarrhea especially in immunocompromised hosts. Diagnosis of the Cryptosporidium oocyst in stool samples by conventional microscopy is labor-intensive and time-consuming. Thus, we aimed to evaluate the usefulness of a copro-antigen enzyme-linked immunosorbent assay (ELISA) test in detecting Cryptosporidium spp. from fecal specimens. For this aim, microscopy and specific antigen detection methods were compared to determine Cryptosporidium spp. In addition, specific antigen by ELISA method in stool was investigated in order to find out whether or not it contributes to the diagnosis of Cryptosporidium spp. One hundred and fifty-four stool specimens taken from patients whose ages ranged from 0 to 86 with diarrhea applied to Department of Parasitology, Balcali Hospital of Cukurova University in Adana, Turkey were used. All samples were examined for Cryptosporidium spp. antigen by ELISA and oocysts via gold standard modified acid-fast staining, between October 2008 and July 2009. Eight (5.19%) specimens were found to be positive by modified acid-fast staining method and 37 (24.03%) specimens by copro-antigen ELISA method were found to be positive. The sensitivity and specificity for copro-antigen ELISA were 100% and 80.1%, respectively. The results of copro-antigen ELISA indicate that the simple, rapid, reliable, and standardized immunoassay test is sensitive and specific for routine diagnosis and may be useful for large-scale epidemiological studies of cryptosporidiosis. PMID:20938687

  7. 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

    2015-04-01

    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

  8. 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

  9. W-transform method for feature-oriented multiresolution image retrieval

    SciTech Connect

    Kwong, M.K.; Lin, B.

    1995-07-01

    Image database management is important in the development of multimedia technology. Since an enormous amount of digital images is likely to be generated within the next few decades in order to integrate computers, television, VCR, cables, telephone and various imaging devices. Effective image indexing and retrieval systems are urgently needed so that images can be easily organized, searched, transmitted, and presented. Here, the authors present a local-feature-oriented image indexing and retrieval method based on Kwong, and Tang`s W-transform. Multiresolution histogram comparison is an effective method for content-based image indexing and retrieval. However, most recent approaches perform multiresolution analysis for whole images but do not exploit the local features present in the images. Since W-transform is featured by its ability to handle images of arbitrary size, with no periodicity assumptions, it provides a natural tool for analyzing local image features and building indexing systems based on such features. In this approach, the histograms of the local features of images are used in the indexing, system. The system not only can retrieve images that are similar or identical to the query images but also can retrieve images that contain features specified in the query images, even if the retrieved images as a whole might be very different from the query images. The local-feature-oriented method also provides a speed advantage over the global multiresolution histogram comparison method. The feature-oriented approach is expected to be applicable in managing large-scale image systems such as video databases and medical image databases.

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

    PubMed

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

    2014-04-01

    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

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. Clustering Methods; Part IV of Scientific Report No. ISR-18, Information Storage and Retrieval...

    ERIC Educational Resources Information Center

    Cornell Univ., Ithaca, NY. Dept. of Computer Science.

    Two papers are included as Part Four of this report on Salton's Magical Automatic Retriever of Texts (SMART) project report. The first paper: "A Controlled Single Pass Classification Algorithm with Application to Multilevel Clustering" by D. B. Johnson and J. M. Laferente presents a single pass clustering method which compares favorably with more…

  17. Shape Recovery: A Visual Method for Evaluation of Information Retrieval Experiments.

    ERIC Educational Resources Information Center

    Rorvig, Mark; Fitzpatrick, Steven

    2000-01-01

    The method described permits visual analysis of information retrieval (IR) experiment results in classic control and treatment group protocols. It is an additional analysis technique for the evaluation of IR procedures that may be conducted within the rich terrain of human visual acuity, supported by two well-known statistical measures. (Contains…

  18. 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.

  19. A method of protein model classification and retrieval using bag-of-visual-features.

    PubMed

    Ma, Jinlin; 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

  20. Performance evaluation of XCO2 retrievals from GOSAT using short-cut full physics methods

    NASA Astrophysics Data System (ADS)

    Hahne, P.; Guerlet, S.; Hasekamp, O. P.; Butz, A.; Partners, T.

    2012-12-01

    Inverse modelling of CO2 surface fluxes requires a global database of atmospheric CO2 measurements with sufficient temporal and spatial coverage and resolution. Column average dry air mixing ratios of CO2 (XCO2) retrieved from short wave infrared spectra observed by the Greenhouse gases Observing SATellite (GOSAT) are promising in that respect. To retrieve XCO2 along with three effective aerosol parameters, the RemoTeC 'full physics' retrieval uses three spectral ranges covering the O2 A-band at around 0.7 μm wavelength as well as a weak and a strong CO2 absorption band at around 1.6 μm and 2 μm wavelength respectively [Butz et al. 2011]. The retrieved aerosol parameters represent the particle amount, particle scattering height, and particle size. We compare this retrieval setup to two short-cut methods, which drop the O2 A-band and just use one or two CO2 absorption bands. Our goal is to avoid retrieval errors which are introduced by instrumental deficiencies in the O2 A-band such as nonlinearity of the detector electronics and inaccurate radiometric calibration. Dropping the O2 A-band implies less information content on aerosol optical properties. Accordingly, the short-cut approaches retrieve only the aerosol amount and, possibly, scattering layer height while assuming the size distribution of the aerosols a given forward model parameter. Comparing two years of global data and validating them against observations of the Total Carbon Column Observing Network (TCCON) we find that the short-cut method exploiting two CO2 absorption bands (around 1.6 μm and 2 μm) performs as good as the standard RemoTeC setup. The short-cut approach using only the strong CO2 absorption band (around 2 μm), however, yields significantly higher scatter of retrieved XCO2. Butz, A., et al. (2011), Toward accurate CO2 and CH4 observations from GOSAT, Geophys. Res. Lett., 38, L14812, doi:10.1029/2011GL047888.

  1. 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.

  2. 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.

  3. 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.

  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. [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

  6. 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.

  7. [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

  8. 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.

  9. 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.

  10. Phase retrieval of microscope objects using the Wavelet-Gabor transform method from holographic filters

    NASA Astrophysics Data System (ADS)

    Hernández-Romo, Martín.; Padilla-Vivanco, Alfonso; Kim, Myung K.; Toxqui-Quitl, Carina

    2014-09-01

    An analysis of an optical-digital system based on the architecture of the Mach-Zehnder interferometer for recording holographic filters is presented. The holographic recording system makes use of one microscope objective in each interferometer arm. Moreover, the Gabor Wavelet Transform is implemented for the holographic reconstruction stage. The samples studied of this research are selected in order to test the retrieval algorithm and to characterize the resolution of the holographic recording system. In this last step, some sections of an USAF1951 resolution chart are used. These samples allow us to study the features of lighting in the recorded system. Additionally, some organic samples are used to proven the capabilities of the method because biological samples have much complex morphological composition than others. With this in mind, we can verify the frequencies recovered with each of the settings set in the retrieval method. Experimental results are presented.

  11. 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).

  12. 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.

  13. 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…

  14. A valuable antigen detection method for diagnosis of acute hepatitis E.

    PubMed

    Wen, Gui-Ping; Tang, Zi-Min; Yang, Fan; Zhang, Ke; Ji, Wen-Fang; Cai, Wei; Huang, Shou-Jie; Wu, Ting; Zhang, Jun; Zheng, Zi-Zheng; Xia, Ning-Shao

    2015-03-01

    Hepatitis E virus (HEV) is a serious public health problem. The commonly used tests that are specific for current HEV infection diagnosis include the detection of anti-HEV IgM and HEV RNA. Here, we report an improved enzyme-linked immunosorbent assay (ELISA) method for HEV antigen detection with a linear range equivalent to 6.3 × 10(3) to 9.2 × 10(5) RNA copies per ml. The monoclonal antibody (MAb) 12F12, a high-ability MAb that binds HEV virus, was selected as the capture antibody from a panel of 95 MAbs. The positive period of HEV antigenemia in infected monkeys using this test was, on average, 3 weeks longer than previously reported and covered the majority of the acute phase. The positive detection rates of IgM, RNA, and new antigen from the first serum samples collected from 16 confirmed acute hepatitis E patients were 81% (13/16), 81% (13/16), and 100% (16/16), respectively. In three patients, the initial serum specimens that tested negative for IgM, despite the presence of symptoms of acute hepatitis and elevated alanine aminotransferase (ALT) levels, were positive for HEV antigen and HEV RNA. In contrast, the serum samples of the three RNA-negative patients were antigen positive (and IgM positive), possibly due to the degradation of HEV nucleic acids. Our results suggest that this new antigen detection method has acceptable concordance with RNA detection and could serve as an important tool for diagnosing acute hepatitis E. PMID:25540394

  15. High speed moire based phase retrieval method for quantitative phase imaging of thin objects without phase unwrapping or aberration compensation

    NASA Astrophysics Data System (ADS)

    Wang, Shouyu; Yan, Keding; Xue, Liang

    2016-01-01

    Phase retrieval composed of phase extracting and unwrapping is of great significance in different occasions, such as fringe projection based profilometry, quantitative interferometric microscopy and moire detections. Compared to phase extracting, phase unwrapping occupies most time consuming in phase retrieval, and it becomes an obstacle to realize real time measurements. In order to increase the calculation efficiency of phase retrieval as well as simplify its procedures, here, a high speed moire based phase retrieval method is proposed which is capable of calculating quantitative phase distributions without phase unwrapping or aberration compensation. We demonstrate the capability of the presented phase retrieval method by both theoretical analysis and experiments. It is believed that the proposed method will be useful in real time phase observations and measurements.

  16. 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.

  17. 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…

  18. An Evaluation of Retrieval Effectiveness Using Spelling-Correction and String-Similarity Matching Methods on Malay Texts.

    ERIC Educational Resources Information Center

    Abu Bakar, Zainab; Sembok, Tengku Mohd T.; Yusoff, Mohammed

    2000-01-01

    Evaluates the effectiveness of spelling-correction and string-similarity matching methods in retrieving similar words in a Malay dictionary associated with a set of query words. Describes experiments that showed the best search combination used a stemming algorithm, and calculates retrieval effectiveness and relevant means measures from weighted…

  19. 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.

  20. A linear method for the retrieval of sun-induced chlorophyll fluorescence from GOME-2 and SCIAMACHY data

    NASA Astrophysics Data System (ADS)

    Köhler, P.; Guanter, L.; Joiner, J.

    2014-12-01

    Global retrievals of near-infrared sun-induced chlorophyll fluorescence (SIF) have been achieved in the last years by means of a number of space-borne atmospheric spectrometers. Here, we present a new retrieval method for medium spectral resolution instruments such as the Global Ozone Monitoring Experiment (GOME-2) and the SCanning Imaging Absorption SpectroMeter for Atmospheric ChartographY (SCIAMACHY). Building upon the previous work by Joiner et al. (2013), our approach solves existing issues in the retrieval such as the non-linearity of the forward model and the arbitrary selection of the number of free parameters. In particular, we use a backward elimination algorithm to optimize the number of coefficients to fit, which reduces also the retrieval noise and selects the number of state vector elements automatically. A sensitivity analysis with simulated spectra has been utilized to evaluate the performance of our retrieval approach. The method has also been applied to estimate SIF from real spectra from GOME-2 and for the first time, from SCIAMACHY. We find a good correspondence of the absolute SIF values and the spatial patterns from the two sensors, which suggests the robustness of the proposed retrieval method. In addition, we examine uncertainties and use our GOME-2 retrievals to show empirically the low sensitivity of the SIF retrieval to cloud contamination.

  1. Two methods for the quantitative analysis of surface antigen expression in acute myeloid leukemia (AML).

    PubMed

    Woźniak, Jolanta

    2004-01-01

    The expression of lineage molecules (CD13 and CD33), c-Kit receptor (CD117), CD34, HLA-DR and adhesion molecule CD49d was assessed in acute myeloid leukemia (AML) blast cells from 32 cases, using direct and indirect quantitative cytometric analysis. High correlation (r=0.8) was found between antigen expression intensity values calculated by direct analysis method (ABC) and by indirect analysis method (RFI). Moreover, the differences in expression intensity of CD13, CD117 and CD34 antigens were found between leukemic and normal myeloblasts. This may be helpful in identification of leukemic cells in the diagnostics of minimal residual disease after treatment in AML patients. PMID:15493582

  2. 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.

  3. Physical retrieval of precipitation water contents from Special Sensor Microwave/Imager (SSM/I) data. Part 2: Retrieval method and applications (report version)

    NASA Technical Reports Server (NTRS)

    Olson, William S.

    1990-01-01

    A physical retrieval method for estimating precipitating water distributions and other geophysical parameters based upon measurements from the DMSP-F8 SSM/I is developed. Three unique features of the retrieval method are (1) sensor antenna patterns are explicitly included to accommodate varying channel resolution; (2) precipitation-brightness temperature relationships are quantified using the cloud ensemble/radiative parameterization; and (3) spatial constraints are imposed for certain background parameters, such as humidity, which vary more slowly in the horizontal than the cloud and precipitation water contents. The general framework of the method will facilitate the incorporation of measurements from the SSMJT, SSM/T-2 and geostationary infrared measurements, as well as information from conventional sources (e.g., radiosondes) or numerical forecast model fields.

  4. Highly accurate retrieval method of Japanese document images through a combination of morphological analysis and OCR

    NASA Astrophysics Data System (ADS)

    Katsuyama, Yutaka; Takebe, Hiroaki; Kurokawa, Koji; Saitoh, Takahiro; Naoi, Satoshi

    2001-12-01

    We have developed a method that allows Japanese document images to be retrieved more accurately by using OCR character candidate information and a conventional plain text search engine. In this method, the document image is first recognized by normal OCR to produce text. Keyword areas are then estimated from the normal OCR produced text through morphological analysis. A lattice of candidate- character codes is extracted from these areas, and then character strings are extracted from the lattice using a word-matching method in noun areas and a K-th DP-matching method in undefined word areas. Finally, these extracted character strings are added to the normal OCR produced text to improve document retrieval accuracy when u sing a conventional plain text search engine. Experimental results from searches of 49 OHP sheet images revealed that our method has a high recall rate of 98.2%, compared to 90.3% with a conventional method using only normal OCR produced text, while requiring about the same processing time as normal OCR.

  5. 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.

  6. 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.

  7. 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.

  8. Skill in Retrievals

    NASA Technical Reports Server (NTRS)

    Aumann, Hartmut H.; Manning, Evan

    2008-01-01

    Retrieval Skill quantifies the ability of one retrieval from a sounder to be more accurate than the best forecast relative to another with the same of another sounder. This is summarized using a Retrieval Anomaly Skill Score (RASS) which is the cor (retrieved-background, truth-background) * sqrt(f), Where f is defined as the ratio of accepted to the possible retrievals. Charts show various features and comparisons of RASS to other methods of retrieval.

  9. Investigating Methods for Nighttime Aerosol Optical Depth Retrieval Using the VIIRS Day/Night Band

    NASA Astrophysics Data System (ADS)

    McHardy, T. M.; Zhang, J.; Reid, J. S.; Hyer, E. J.

    2014-12-01

    Most of the existing aerosol sensitive passive sensors focus on detecting day time aerosol properties. The Visible/Infrared Imaging Radiometer Suite (VIIRS) contains a Day/Night Band (DNB) which is capable of remote sensing of aerosol signals at night. This brings an opportunity for studying nighttime aerosol optical properties at a high spatial and temporal resolution. Using VIIRS DNB data, several methods are developed for retrieving aerosol optical depth values over regions with artificial city lights. These methods are based on changes in diffuse scattering of artificial light due to particles in the atmosphere. The first method compares average radiance values of artificial light sources against that of nearby dark pixels. The second method examines the dispersion of radiance values above an artificial light source. The strengths and weaknesses of each method are investigated over selected artificial city light sources that are within close proximity to Aerosol Robotic Network (AERONET) sites. This study suggests that nighttime retrievals of aerosol properties at high spatial and temporal resolution using the VIIRS DNB may be viable in the future.

  10. A linear method for the retrieval of sun-induced chlorophyll fluorescence from GOME-2 and SCIAMACHY data

    NASA Astrophysics Data System (ADS)

    Köhler, P.; Guanter, L.; Joiner, J.

    2015-06-01

    Global retrievals of near-infrared sun-induced chlorophyll fluorescence (SIF) have been achieved in the last few years by means of a number of space-borne atmospheric spectrometers. Here, we present a new retrieval method for medium spectral resolution instruments such as the Global Ozone Monitoring Experiment-2 (GOME-2) and the SCanning Imaging Absorption SpectroMeter for Atmospheric CHartographY (SCIAMACHY). Building upon the previous work by Guanter et al. (2013) and Joiner et al. (2013), our approach provides a solution for the selection of the number of free parameters. In particular, a backward elimination algorithm is applied to optimize the number of coefficients to fit, which reduces also the retrieval noise and selects the number of state vector elements automatically. A sensitivity analysis with simulated spectra has been utilized to evaluate the performance of our retrieval approach. The method has also been applied to estimate SIF at 740 nm from real spectra from GOME-2 and for the first time, from SCIAMACHY. We find a good correspondence of the absolute SIF values and the spatial patterns from the two sensors, which suggests the robustness of the proposed retrieval method. In addition, we compare our results to existing SIF data sets, examine uncertainties and use our GOME-2 retrievals to show empirically the relatively low sensitivity of the SIF retrieval to cloud contamination.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. Management and Design Tools for Document Retrieval Systems: A Method for Predicting Quantity Output.

    ERIC Educational Resources Information Center

    Fiorello, Marco R.

    The existing volume and increasing growth rate of documented information has resulted in numerous efforts to construct operational Document Storage and Retrieval Systems, as a practical solution to the demand for information storage and retrieval. Accompanying the surge to build more and better and bigger Document Retrieval Systems (DRSs), was the…

  16. 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. PMID:24837652

  17. 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.

  18. [Quantitative retrieval of chlorophyll a concentration in Taihu Lake using machine learning methods].

    PubMed

    Zhang, Yu-Chao; Qian, Xin; Qian, Yu; Liu, Jian-Ping; Kong, Fan-Xiang

    2009-05-15

    We evaluated the performance of two machine learning methods, artificial neural net (ANN) and support vector machine (SVM), for estimation of chlorophyll a in Taihu Lake from remote sensing data. The theoretical analysis has been done from basic theory and learning target of these two methods first. Then two empirical algorithms have been developed to relate reflectance of MODIS to in situ concentrations of chlorophyll a. The performance of ANN and SVM is comparatively analyzed in terms of validation, stability and robustness assessment and chlorophyll a distribution of Taihu Lake from two algorithms. The root of mean square deviation (RMSE) and average relative error (ARE) of validation data is only 5.85 and 26.5% of SVM retrieval model, however, RMSE and ARE of ANN model is 13.04 and 46.8%. Stability and robustness assessment suggest that SVM provides the better performance than ANN. And the retrieval results show that the chlorophyll a distribution of the whole lake from two algorithms is similar, however, the chlorophyll a concentration in the eastern region and central region of Taihu Lake is distorted by ANN model because of the limitations, such as learning target setting and over-learning in net construction. PMID:19558096

  19. A method for retrieving vertical ozone profiles from limb scattered measurements

    NASA Astrophysics Data System (ADS)

    Wang, Zijun; Chen, Shengbo; Yang, Chunyan; Jin, Lihua

    2011-10-01

    A two-step method is employed in this study to retrieve vertical ozone profiles using scattered measurements from the limb of the atmosphere. The combination of the Differential Optical Absorption Spectroscopy (DOAS) and the Multiplicative Algebraic Reconstruction Technique (MART) is proposed. First, the limb radiance, measured over a range of tangent heights, is processed using the DOAS technique to recover the effective column densities of atmospheric ozone. Second, these effective column densities along the lines of sight (LOSs) are inverted using the MART coupled with a forward model SCIATRAN (radiative transfer model for SCIAMACHY) to derive the ozone profiles. This method is applied to Optical Spectrograph and Infra Red Imager System (OSIRIS) radiance, using the wavelength windows 571-617 nm. Vertical ozone profiles between 10 and 48 km are derived with a vertical resolution of 1 km. The results illustrate a good agreement with the cloud-free coincident SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) ozone measurements, with deviations less than ±10% (±5% for altitudes from 17 to 47 km). Furthermore, sensitivities of retrieved ozone to aerosol, cloud parameters and NO2 concentration are also investigated.

  20. 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.

  1. A Regularized Total Least Square Method for Snow Profiles Retrievals from Radar Back Scattering of CLOUDSAT Data

    NASA Astrophysics Data System (ADS)

    Koner, P. K.; Battaglia, A.; Simmer, C.

    2008-05-01

    Snowfall represents a key component of the water cycle in high latitude/polar regions. The particle size and shape distribution is the key parameter to understand and retrieve snow properties from remote satellite measurements. A regularized total least squares (RTLS) method is successfully introduced in a retrieval of snow profiling size distribution parameters based only on W-band radar back-scattering profiles. The RTLS method is extensively used in a variety of scientific disciplines (where both the Jacobian and the measurement vectors are contaminated by noise) such as signal processing, automatic control, statistics, economy, biology, medicine and remote sensing trace gases retrievals as well. The forward model uses DDA-based backscattering look-up tables of non-spherical particles with temperature-dependent parameterizations of the size and shape distributions of the snow particles derived from up-to-date in situ measurements of snow events. Synthetic retrievals (with all the retrieval variables known) are presented first to assess the potential of the new technique. Then the retrieval is performed using the measured radar reflectivity factor by the 94 GHz CloudSat Profiling Radar with additional information about the temperature profile. The number density and size distribution width have been solved by minimizing the distance between the measured data and the simulated forward model runs. We have used the RTLS method for an optimum regularization and the Gauss-Newton adjunct with mixed "line search" methods to solve the nonlinearity of the forward model.

  2. Performance of a FieldSpec spectroradiometer for aerosol optical depth retrieval: method and preliminary results.

    PubMed

    Bassani, Cristiana; Estellés, Víctor; Campanelli, Monica; Cavalli, Rosa Maria; Martínez-Lozano, José Antonio

    2009-04-10

    The performance of a FieldSpec spectroradiometer for retrieving aerosol optical depth (AOD) has been assessed after modifying its basic configuration in order to measure direct solar irradiance at ground level. The FieldSpec measurements were obtained during four summertime days in the years 2004 and 2005, over a Spanish agricultural site in Barrax, Albacete (30 degrees 3(') N, 2 degrees 6(') W, 700 m a.s.l.), in the framework of two European Space Agency mission remote sensing field campaigns. From the whole FieldSpec spectral domain (350-2500 nm) the AOD was extracted for channels within atmospheric windows. The instrument was calibrated by means of the standard Langley plot method, performed at a high mountain site in Italy. The AOD retrieved by the FieldSpec has been validated by comparison with the AOD obtained from a colocated CIMEL CE318 Sun photometer. The FieldSpec AOD spectra were convoluted with the CE318 filter transmission functions in order to make both datasets comparable. Our results show that both datasets are very similar (R(2) around 0.9) for all the channels from the CE318, with an average deviation of about 0.02. The temporal evolution of the AOD was accurately monitored by the FieldSpec under different atmospheric conditions, as was the case for a previously reported mineral dust intrusion. As a conclusion, the comparison performed in this study shows that the FieldSpec spectroradiometer is a suitable instrument for retrieving the AOD in different atmospheric situations. PMID:19363533

  3. 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

  4. A similarity retrieval method for functional magnetic resonance imaging (fMRI) statistical maps

    NASA Astrophysics Data System (ADS)

    Tungaraza, R. F.; Guan, J.; Rolfe, S.; Atmosukarto, I.; Poliakov, A.; Kleinhans, N. M.; Aylward, E.; Ojemann, J.; Brinkley, J. F.; Shapiro, L. G.

    2009-02-01

    We propose a method for retrieving similar fMRI statistical images given a query fMRI statistical image. Our method thresholds the voxels within those images and extracts spatially distinct regions from the voxels that remain. Each region is defined by a feature vector that contains the region centroid, the region area, the average activation value for all the voxels within that region, the variance of those activation values, the average distance of each voxel within that region to the region's centroid, and the variance of the voxel's distance to the region's centroid. The similarity between two images is obtained by the summed minimum distance of their constituent feature vectors. Results on a dataset of fMRI statistical images from experiments involving distinct cognitive tasks are shown.

  5. 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.

  6. 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.

  7. Retrieval method for upper-tropospheric water vapor profiles from shuttle-borne microwave measurements

    NASA Astrophysics Data System (ADS)

    Feist, Dietrich G.; Peter, Reto; Kaempfer, Niklaus A.

    1997-01-01

    The small amount of water vapor in the upper troposphere plays an important role in the Earth's climate system, e.g. by determining the occurrence and distribution of cirrus clouds. However, only little is known about the vertical distribution of upper tropospheric humidity (UTH). In this paper we propose a method for the retrieval of UTH from measurements taken by the Millimeter wave Atmospheric Sounder (MAS) onboard the space shuttle. MAS is a microwave limb sounder that was originally built to measure trace gases in the stratosphere and mesosphere. One of its channels around 204 Hz is sensitive to the amount of water vapor near the tangent point down to altitudes of about 7 km. Retrievals performed with simulated data have shown promising results. First comparisons with measured data show large discrepancies between actual measurements and the predictions of the widely used Liebe model. Preliminary results suggest that the Liebe model strongly underestimates the dry air continuum in this frequency range for the limb-sounding geometry.

  8. Improved method for retrieving the aerosol optical properties without the numerical derivative for Raman-Mie lidar

    NASA Astrophysics Data System (ADS)

    Gong, Wei; Wang, Wei; Mao, Feiyue; Zhang, Jinye

    2015-08-01

    Raman-Mie light detection and ranging (lidar) is a very useful tool for research on atmospheric aerosol optical properties with high spatial-temporal resolution. However, many uncertainties still exist in data retrieval because traditional retrieval methods need to calculate the numerical derivative for aerosol extinction coefficient (AEC), which may cause large errors, particularly with low signal-to-noise ratios. Thus, we present an improved method for retrieving aerosol optical properties. We re-formulate the N2-Raman lidar equation to obtain an unknown term which contains the AEC at the Mie wavelength. We replace the unknown term of the equation in traditional method for retrieving aerosol backscatter coefficient (ABC). Then, AEC can be retrieved by the accurate ABC and Mie lidar signal without calculating the numerical derivative. Tests on the simulated and measured signals show that results of our method and those of the traditional method have similar tendencies. However, our method is more accurate and robust, and the significant errors of AEC caused by the numerical derivative can be reduced.

  9. 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

  10. 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. PMID:23808842

  11. 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

  12. 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.

  13. 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

    2015-01-01

    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

  14. 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

  15. 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.

  16. 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.

  17. An automatic Planetary Boundary Layer height retrieval method with compact EZ backscattering Lidar

    NASA Astrophysics Data System (ADS)

    Loaec, S.; Sauvage, L.; Boquet, M.; Lolli, S.; Rouget, V.

    2009-09-01

    Bigger strongly urbanized cities in the world are often exposed to atmospheric pollution events. To understand the chemical and physical processes that are taking place in these areas it is necessary to describe correctly the Planetary Boundary Layer (PBL) dynamics and the PBL height evolution. For these proposals, a compact and rugged eye safe UV Lidar, the EZLIDAR™, was developed together by CEA/LMD and LEOSPHERE (France) to study and investigate structural and optical properties of clouds and aerosols and PBL time evolution. EZLIDAR™ has been validated by different remote and in-situ instruments as MPL Type-4 Lidar manufactured by NASA at ARM/SGP site or the LNA (Lidar Nuage Aerosol) at the Laboratoire de Metereologie Dynamique LMD (France) and during several intercomparison campaigns. EZLIDAR™ algorithm retrieves automatically the PBL height in real-time. The method is based on the detection of the slope of the signal linked to a sharp change in concentration of the aerosols. Once detected, the different layers are filtered on a 15mn sample and classified between nocturnal, convective or residual layer, depending on the time and date. This method has been validated against those retrieved by the algorithm STRAT from data acquired at IPSL, France, showing 95% of correlation. In this paper are presented the results of the intercomparison campaign that took place in Orleans, France and Mace Head, Ireland in the framework of ICOS (Integrated Carbon Observation System) project, where the EZ Lidar™ worked under all weather conditions, clear sky, fog, low clouds, during the whole month of October 2008. Moreover, thanks to its 3D scanning capability, the EZLIDAR was able to provide the variability of the PBL height around the site, enabling the scientists to estimate the flux intensities that play a key role in the radiative transfer budget and in the atmospheric pollutants dispersion.

  18. Retrieval of temperature from a multiple-channel Rayleigh-scatter lidar using an optimal estimation method.

    PubMed

    Sica, R J; Haefele, A

    2015-03-10

    The measurement of temperature in the middle atmosphere with Rayleigh-scatter lidars is an important technique for assessing atmospheric change. Current retrieval schemes for this temperature have several shortcomings, which can be overcome by using an optimal estimation method (OEM). Forward models are presented that completely characterize the measurement and allow the simultaneous retrieval of temperature, dead time, and background. The method 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, 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, which are consistent with previous methods, while requiring minimal computational time. This demonstrated success of lidar temperature retrievals using an OEM opens new possibilities in atmospheric science for measurement integration between active and passive remote sensing instruments. PMID:25968361

  19. 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. PMID:23728136

  20. 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.

  1. 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.

  2. 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

  3. A linear method for the retrieval of sun-induced chlorophyll fluorescence from GOME-2 and SCIAMACHY data

    NASA Astrophysics Data System (ADS)

    Köhler, Philipp; Guanter, Luis; Joiner, Joanna

    2015-04-01

    Global retrievals of near-infrared sun-induced chlorophyll fluorescence (SIF) have been achieved in the last several years by means of space-borne atmospheric spectrometers. SIF is an electromagnetic signal emitted by the chlorophyll-a of photosynthetically active vegetation in the 650-850 nm spectral range. It represents a part of the excess energy during the process of photosynthesis and provides a measure of photosynthetic activity. The key challenge to retrieve SIF from space is to isolate the signal from the about 100 times more intense reflected solar radiation in the measured top of atmosphere (TOA) radiance spectrum. Nevertheless, it has been demonstrated that a number of satellite sensors provide the necessary spectral and radiometric performance to evaluate the in-filling of solar Fraunhofer lines and/or atmospheric absorption features by SIF. We will present recent developments for the retrieval of SIF from medium spectral resolution space-borne spectrometers such as the Global Ozone Monitoring Experiment (GOME-2) and the Scanning Imaging Absorption SpectroMeter for Atmospheric ChartographY (SCIAMACHY). Building upon the previous work by Joiner et al. 2013, our approach solves existing issues in the retrieval such as the non-linearity of the forward model and the arbitrary selection of the number of free parameters. In particular, we use a backward elimination algorithm to optimize the number of coefficients to fit, which reduces also the retrieval noise and selects the number of state vector elements automatically. A sensitivity analysis with simulated spectra has been utilized to evaluate the performance of our retrieval approach. The method has also been applied to estimate SIF from real spectra from GOME-2 and for the first time, from SCIAMACHY. We are able to present a time series of GOME-2 SIF results covering the 2007-2011 time period and SCIAMACHY SIF results between 2003-2011. This represents an almost one decade long record of global SIF. We

  4. 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.

  5. The impact of the choice of radiative transfer model and inversion method on the OSIRIS ozone and nitrogen dioxide retrievals

    NASA Astrophysics Data System (ADS)

    Haley, Craig; McLinden, Chris; Sioris, Christopher; Brohede, Samuel

    Key to the retrieval of stratospheric minor species information from limb-scatter measurements are the selections of a radiative transfer model (RTM) and inversion method (solver). Here we assess the impact of choice of RTM and solver on the retrievals of stratospheric ozone and nitrogen dioxide from the OSIRIS instrument using the ‘Ozone Triplet' and Differential Optical Absorption Spectroscopy (DOAS) techniques that are used in the operational Level 2 processing algorithms. The RTMs assessed are LIMBTRAN, VECTOR, SCIARAYS, and SASKTRAN. The solvers studied include the Maximum A Posteriori (MAP), Maximum Likelihood (ML), Iterative Least Squares (ILS), and Chahine methods.

  6. 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…

  7. 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…

  8. Utility of PCR, Culture, and Antigen Detection Methods for Diagnosis of Legionellosis

    PubMed Central

    Chen, Derrick J.; Procop, Gary W.; Vogel, Sherilynn; Yen-Lieberman, Belinda

    2015-01-01

    The goal of this retrospective study was to evaluate the performance of different diagnostic tests for Legionnaires' disease in a clinical setting where Legionella pneumophila PCR had been introduced. Electronic medical records at the Cleveland Clinic were searched for Legionella urinary antigen (UAG), culture, and PCR tests ordered from March 2010 through December 2013. For cases where two or more test methods were performed and at least one was positive, the medical record was reviewed for relevant clinical and epidemiologic factors. Excluding repeat testing on a given patient, 19,912 tests were ordered (12,569 UAG, 3,747 cultures, and 3,596 PCR) with 378 positive results. The positivity rate for each method was 0.4% for culture, 0.8% for PCR, and 2.7% for UAG. For 37 patients, at least two test methods were performed with at least one positive result: 10 (27%) cases were positive by all three methods, 16 (43%) were positive by two methods, and 11 (30%) were positive by one method only. For the 32 patients with medical records available, clinical presentation was consistent with proven or probable Legionella infection in 84% of the cases. For those cases, the sensitivities of culture, PCR, and UAG were 50%, 92%, and 96%, respectively. The specificities were 100% for culture and 99.9% for PCR and UAG. PMID:26292304

  9. Use of thermal infrared pictures for retrieving intertidal DEM by the waterline method: advantages and limitations

    NASA Astrophysics Data System (ADS)

    Gaudin, D.; Delacourt, C.; Allemand, P.

    2010-12-01

    Digital Elevation Models (DEM) of the intertidal zones have a growing interest for ecological and land development purposes. They are also a fundamental tool for monitoring current sedimentary movements in those low energy environments. Such DEMs have to be constructed with a centimetric resolution as the topographic changes are not predictable and as sediment displacements are weak. Direct construction of DEM by GPS in these muddy environment is difficult: photogrammetric techniques are not efficient on uniform coloured surfaces and terrestrial laser scans are difficult to stabilize on the mud, due to humidity. In this study, we propose to improve and to apply the waterline method to retrieve DEMs in intertidal zones. This technique is based on monitoring accurately the boundary between sand and water during a whole tide rise with thermal infrared images. The DEM is made by stacking all these lines calibrated by an immersed pressure sensor. Using thermal infrared pictures, instead of optical ones, improves the detection of the waterline, since mud and water have very different responses to sun heating and a large emissivity contrast. However, temperature retrieving from thermal infrared data is not trivial, since the luminance of an object is the sum of a radiative part and a reflexive part, whose relative proportions are given by the emissivity. In the following equation, B accounts for the equivalent blackbody luminance, and Linc is the incident luminance : Ltot}=L{rad}+L_{refl=ɛ B+(1-ɛ )Linc The infrared waterline technique has been used for the monitoring of a beach located on the Aber Benoit, 8.5km away from the open sea. The site is mainly constituted of mud, and waves are very small (less than one centimeter high), which are the ideal conditions for using the waterline method. A few measurements have been made to make differential heigh maps of sediments. We reached a mean resolution of 2cm and a vertical accuracy better than one centimeter. The results

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. Application of a modified DOAS method for total ozone retrieval from GOME data at high polar latitudes

    NASA Astrophysics Data System (ADS)

    Coldewey-Egbers, M.; Weber, M.; Buchwitz, M.; Burrows, J. P.

    2004-01-01

    Since 1995, the Global Ozone Monitoring Experiment (GOME) on board the second European Remote Sensing satellite provides information about spatial distribution and temporal variation of total ozone. Current operational data products are generated using the Differential Optical Absorption Spectroscopy (DOAS) technique. Various validation exercises indicate shortcomings in the current retrieval using the standard DOAS approach. Especially under ozone hole conditions at high polar latitudes GOME tends to overestimate total ozone as compared to ground-based measurements. In this study, we introduce a modified DOAS method for ozone retrieval from GOME which fits directly the vertical columns rather than slant columns. We present preliminary results which demonstrate the advantage of the new approach. It will be shown that not only the differences to ground-based data are reduced but also the fit residuals are improved in comparison with the operational retrieval.

  16. 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).

  17. An Improved Method to Retrieve Surface Emissivity in a Canary Pine Forest Using Aster Data

    NASA Astrophysics Data System (ADS)

    Barreto-Velasco, Africa; Hernandez-Leal, Pedro A.; Arbelo, Manuel; Podesta, Guillermo P.

    2012-07-01

    The widely-used Temperature and Emissivity Separation (TES) algorithm has been shown to provide reliable temperature and emissivity estimates from land-leaving thermal data. Nevertheless, TES has some important limitations mainly related to its inability to correct important inaccuracies for gray bodies, such as vegetation. In this study, this problem is addressed through an improvement to the current NEM (Normalized Emissivity Method) module included in the TES algorithm. The proposed method, called Modified NEM (ModNEM), has been specifically designed to retrieve an accurate surface emissivity for bodies with a spectral behavior typical of gray-bodies, i. e., flat and near spectrally invariant. ModNEM selects two different approximations of surface temperature instead of the usual maximum temperature, with the aim of accounting for the peculiar spectral behavior of brightness temperature and emissivity for vegetation. The NEM and TES, as well as the ModNEM, have been used to recover surface emissivity in a pine forest located in Tenerife Island (Canary Islands, Spain) using data from the Advanced Spaceborne Thermal Emission Reflection Radiometer (ASTER). Results have been compared and validated using reference emissivity values obtained from the pines by means of the box method. This validation study showed that high uncertainties are associated with the standard techniques (up to 0.034), whereas ModNEM results in lower uncertainties in emissivity estimates (< 0.005 for all ASTER channels). The results suggest that the current approximations in the existing NEM module are not suitable for surfaces with a spectral behavior similar to a grey body. This work was supported by MICINN under Grant CGL2010-22189-C02.

  18. 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…

  19. 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

  20. A comparison of two methods for indexing and retrieval from a full-text medical database.

    PubMed

    Hersh, W R; Hickam, D H

    1993-01-01

    The objective of this study was to compare how well medical professionals are able to retrieve relevant literature references using two computerized literature searching systems that provide automated (non-human) indexing of content. The first program was SAPHIRE, which features concept-based indexing, free-text input of queries, and ranking of retrieved references for relevance. The second program was SWORD, which provides single-word searching using Boolean operators (AND, OR). Sixteen fourth-year medical students participated in the study. The database for searching was six volumes from the 1989 Yearbook series. The queries were ten questions generated on teaching rounds. All subjects searched half the queries with each program. After the searching, each subject was given a questionnaire about prior experience and preferences about the two programs. Recall (proportion of relevant articles retrieved from the database) and precision (proportion of relevant articles in the retrieved set) were measured for each search done by each participant. Mean recall was 57.6% with SAPHIRE; it was 58.6% with SWORD. Precision was 48.1% with SAPHIRE vs 57.6% with SWORD. Each program was rated easier to use than the other by half of the searchers, and preferences were associated with better searching performance for that program. Both systems achieved recall and precision comparable to existing systems and may represent effective alternatives to MEDLINE and other retrieval systems based on human indexing for searching medical literature. PMID:8412551

  1. 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. PMID:1954783

  2. A method for retrieving the cumulus entrainment rate from ground based observations

    NASA Astrophysics Data System (ADS)

    Wagner, Timothy J.

    2011-12-01

    The entrainment of drier environmental air into cumulus clouds affects the impact that these clouds have on the environment by modifying their radiative, microphysical, and thermodynamic characteristics. Entrainment is a difficult parameter to observe directly, and heretofore has been obtained from occasional aircraft penetrations. To increase the number of cumulus entrainment rate observations under a wide range of atmospheric conditions, an algorithm for retrieving the cumulus entrainment rate from ground-based remote sensing observations has been developed. This algorithm, called the Entrainment Rate In Cumulus Algorithm (ERICA), uses the suite of instruments at the Southern Great Plains (SGP) site of the United States Department of Energy's Atmospheric Radiation Measurement (ARM) Climate Research Facility as inputs into a Gauss-Newton optimal estimation scheme. The forward model in this algorithm is the Explicit Mixing Parcel Model (EMPM), a cloud parcel model that treats entrainment as a series of discrete mixing events. Output from EMPM is used to calculate quantities that can be observed from the surface, including effective radius and liquid water path. The entrainment rate in EMPM is adjusted iteratively until the modeled output converges to the observations. Sensitivity testing and error and information content analysis show that ERICA is a robust method for obtaining accurate estimates of entrainment rate without the drawbacks of aircraft observations. Results from a three-month trial of ERICA show significant variability of the entrainment rate of clouds in a single day and from one day to the next. The mean value from this analysis corresponds well with prior knowledge of the entrainment rate.

  3. An Easy and Efficient Method for Native and Immunoreactive Echinococcus granulosus Antigen 5 Enrichment from Hydatid Cyst Fluid

    PubMed Central

    Pagnozzi, Daniela; Biosa, Grazia; Addis, Maria Filippa; Mastrandrea, Scilla; Masala, Giovanna; Uzzau, Sergio

    2014-01-01

    Background Currently, the serodiagnosis of cystic echinococcosis relies mostly on crude Echinococcus granulosus hydatid cyst fluid as the antigen. Consequently, available immunodiagnostic tests lack standardization of the target antigen and, in turn, this is reflected on poor sensitivity and specificity of the serological diagnosis. Methodology/Principal Findings Here, a chromatographic method enabling the generation of highly enriched Antigen 5 (Ag5) is described. The procedure is very easy, efficient and reproducible, since different hydatid cyst fluid (HCF) sources produced very similar chromatograms, notwithstanding the clearly evident and extreme heterogeneity of the starting material. In addition, the performance of the antigen preparation in immunological assays was preliminarily assessed by western immunoblotting and ELISA on a limited panel of cystic echinococcosis patients and healthy controls. Following western immunoblotting and ELISA experiments, a high reactivity of patient sera was seen, with unambiguous and highly specific results. Conclusions/Significance The methods and results reported open interesting perspectives for the development of sensitive diagnostic tools to enable the timely and unambiguous detection of cystic echinococcosis antibodies in patient sera. PMID:25119821

  4. Retrieval of size and refractive index of spherical particles by multiangle light scattering: neural network method application.

    PubMed

    Berdnik, Vladimir V; Loiko, Valery A

    2009-11-10

    A method to retrieve the radius and the relative refractive index of spherical homogeneous nonabsorbing particles by multiangle scattering is proposed. It is based on the formation of noise-resistant functionals of the scattered intensity, which are invariant with respect to the linear homogeneous transformations of an intensity-based signal and approximation of the retrieved parameters' dependence on the functionals by a feed-forward neural network. The neural network was trained by minimization of the mean squared relative error in the range of particle radii from 0.6 mkm up to 13.6 mkm and relative refractive index from 1.015 up to 1.28. In comparison with training on a minimum of the mean squared error, this method enables one to increase the accuracy of the radius retrieval in the range of radii from 0.6 to 2 microm and refractive index in the range from 1.015 to 1.1. The values of intensity of light scattered in the interval of angles 10 degrees-60 degrees are used as input data. If the measurement error is 20%, the mean errors of the radius and relative refractive index are 0.8% and 7%, respectively. The results obtained by the proposed method and by the trial and error method with published experimental data (measured with a scanning flow cytometer) are compared. The maximal difference in the retrieval results of radius and the relative refractive index of particles obtained by both methods is under 5%. PMID:19904314

  5. 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. PMID:23571919

  6. Applying Information-Retrieval Methods to Software Reuse: A Case Study.

    ERIC Educational Resources Information Center

    Stierna, Eric J.; Rowe, Neil C.

    2003-01-01

    Discusses reuse of existing software for new purposes as a key aspect of efficient software engineering by matching formal written requirements used to define the new and the old software. Explores two matching methodologies that use information retrieval techniques and describes test results from a comparison of two military systems. (Author/LRW)

  7. 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…

  8. Comparing different methods to retrieve cloud top height from Meteosat satellite data

    NASA Astrophysics Data System (ADS)

    Tabone, I.; Briz, S.; Anzalone, A.; De Castro, A. J.; Lopez, F.; Ferrarese, S.; Isgrò, F.; Cassardo, C.; Cremonini, R.; Bertaina, M.

    2015-10-01

    Cloud parameters such as the Cloud Top Height (CTH), Cloud Top Temperature (CTT), emissivity, particle size and optical depth have always been matter of interest for the atmospheric community. Particularly the CTH provides information leading to better understand the cloud radiative effects. Although there are many meteorological satellites providing the CTH, there are other sensors, not devoted to this purpose, that give some information from which this crucial parameter can be estimated. In this contribution we will describe three different methodologies to retrieve the CTH. The first technique is based on stereo-vision algorithms and requires two different views of the same scene and does not need of extra atmospheric information. In the second one, brightness temperatures in two IR spectral bands are converted to real cloud temperature by means of the proposed algorithms. From the CTT, the CTH is estimated using temperature vertical profiles (measured or modeled). The third technique retrieves the CTH from the output parameters of post event simulations performed by a Numerical Weather Prediction (NWP) model that in this work will be the mesoscale model WRF (Weather Research Forecast). This article presents a preliminary work, in which the heights retrieved by the three methodologies applied to the geostationary satellite Meteosat 10 are compared with the heights given by MODIS sensor installed on the polar satellite AQUA. This promising results show that valuable information about CTH can be retrieved from Meteosat which provide high frequency and large scale data useful for weather and climate research.

  9. 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

  10. 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.

  11. 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

  12. 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.

  13. Enzyme-linked immunosorbent assay for rubella immunoglobulin G: new method for attachment of antigens to microtiter plates.

    PubMed Central

    Skurrie, I J; Gilbert, G L

    1983-01-01

    Many of the enzyme-linked immunosorbent assay (ELISA) techniques previously described for detection of rubella-specific antibodies employ complex technology not available in routine diagnostic laboratories. The method described allows the use of commercially available rubella hemagglutination inhibition (HI) antigen. Passive adsorption of these antigens to plastic is variable, but with the use of albumin as a bridge, it is possible to attach the antigen reliably to the plastic wells. Over 1,500 sera were tested by both HI and ELISA techniques to detect the presence of rubella antibodies. These sera were selected with a bias towards those with low levels of rubella-specific antibody, since it has been demonstrated that it is in this range that discrepancies are more likely to occur between HI and ELISA techniques. In 99% of the sera tested, the results of both techniques were in agreement. On the basis of these results, the technique offers a useful alternative to the routine rubella HI test and other ELISA techniques which need sophisticated antigen preparations. PMID:6863497

  14. 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

  15. 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

  16. 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

  17. A Study of Global Cirrus Optical and Microphysical Properties Based on an Efficient Infrared Retrieval Method

    NASA Astrophysics Data System (ADS)

    Li, Y.; Heidinger, A. K.

    2015-12-01

    Current studies of global upper tropospheric cirrus clouds from satellite observations are focused on daytime, primarily due to dependence on solar reflectance in the retrieval technique. Here, utilizing an accurate and efficient infrared based retrieval technique, cirrus cloud optical properties, including cloud optical thickness and effective particle size, are investigated using Aqua MODIS data during both day and night conditions. It is revealed that contrast of averaged day and night properties is small, despite of an apparent distinction in occurrence frequencies. The geographical differences are more pronounced. Seasonal variations, vertical distributions, as well as interrelations with other macrophysical and microphysical properties are also studied. The findings of this study will be useful for developing future cirrus cloud parameterization schemes in climate models.

  18. 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.

  19. 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. PMID:26480164

  20. An oil film information retrieval method overcoming the influence of sun glitter, based on AISA+ airborne hyper-spectral image

    NASA Astrophysics Data System (ADS)

    Zhan, Yuanzeng; Mao, Tianming; Gong, Fang; Wang, Difeng; Chen, Jianyu

    2010-10-01

    As an effective survey tool for oil spill detection, the airborne hyper-spectral sensor affords the potentiality for retrieving the quantitative information of oil slick which is useful for the cleanup of spilled oil. But many airborne hyper-spectral images are affected by sun glitter which distorts radiance values and spectral ratios used for oil slick detection. In 2005, there's an oil spill event leaking at oil drilling platform in The South China Sea, and an AISA+ airborne hyper-spectral image recorded this event will be selected for studying in this paper, which is affected by sun glitter terribly. Through a spectrum analysis of the oil and water samples, two features -- "spectral rotation" and "a pair of fixed points" can be found in spectral curves between crude oil film and water. Base on these features, an oil film information retrieval method which can overcome the influence of sun glitter is presented. Firstly, the radiance of the image is converted to normal apparent reflectance (NormAR). Then, based on the features of "spectral rotation" (used for distinguishing oil film and water) and "a pair of fixed points" (used for overcoming the effect of sun glitter), NormAR894/NormAR516 is selected as an indicator of oil film. Finally, by using a threshold combined with the technologies of image filter and mathematic morphology, the distribution and relative thickness of oil film are retrieved.

  1. 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

  2. Differential uncertainty analysis for evaluating the accuracy of S-parameter retrieval methods for electromagnetic properties of metamaterial slabs.

    PubMed

    Hasar, Ugur Cem; Barroso, Joaquim J; Sabah, Cumali; Kaya, Yunus; Ertugrul, Mehmet

    2012-12-17

    We apply a complete uncertainty analysis, not studied in the literature, to investigate the dependences of retrieved electromagnetic properties of two MM slabs (the first one with only split-ring resonators (SRRs) and the second with SRRs and a continuous wire) with single-band and dual-band resonating properties on the measured/simulated scattering parameters, the slab length, and the operating frequency. Such an analysis is necessary for the selection of a suitable retrieval method together with the correct examination of exotic properties of MM slabs especially in their resonance regions. For this analysis, a differential uncertainty model is developed to monitor minute changes in the dependent variables (electromagnetic properties of MM slabs) in functions of independent variables (scattering (S-) parameters, the slab length, and the operating frequency). Two complementary approaches (the analytical approach and the dispersion model approach) each with different strengths are utilized to retrieve the electromagnetic properties of various MM slabs, which are needed for the application of the uncertainty analysis. We note the following important results from our investigation. First, uncertainties in the retrieved electromagnetic properties of the analyzed MM slabs drastically increase when values of electromagnetic properties shrink to zero or near resonance regions where S-parameters exhibit rapid changes. Second, any low-loss or medium-loss inside the MM slabs due to an imperfect dielectric substrate or a finite conductivity of metals can decrease these uncertainties near resonance regions because these losses hinder abrupt changes in S-parameters. Finally, we note that precise information of especially the slab length and the operating frequency is a prerequisite for accurate analysis of exotic electromagnetic properties of MM slabs (especially multiband MM slabs) near resonance regions. PMID:23263141

  3. 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.

  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. 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.

  6. 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.

  7. 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.

  8. Antigen retrieval, blocking, detection and visualisation systems in immunohistochemistry: a review and practical evaluation of tyramide and rolling circle amplification systems.

    PubMed

    Warford, Anthony; Akbar, Hameed; Riberio, Deise

    2014-11-01

    To achieve specificity and sensitivity using immunohistochemistry it is necessary to combine the application of validated primary antibodies with optimised pre-treatment, detection and visualisation steps. The influence of these surrounding procedures is reviewed. A practical evaluation of tyramide signal amplification and rolling circle amplification detection methods is provided in which formalin fixed paraffin embedded sections of adenocarcinomas of breast, colon and lung together with squamous metaplasia of lung were immunostained with CD20 and CK19 primary antibodies. The results indicate that the detection systems are of comparable sensitivity and specificity. PMID:24631890

  9. Error calculation and analysis for an improved wind retrieval method based on the ground-based Fabry-Perot interferometer measurements

    NASA Astrophysics Data System (ADS)

    Wang, Houmao; Wang, Yongmei

    2015-11-01

    A ground-based Fabry-Perot interferometer (FPI) fabricated by American National Center for Atmospheric Research (A-NCAR) was deployed in Kelan (111.6° E, 38.7° N), in middle of China, to observe OH 892.0 nm, OI 630.0 nm, and OI 557.7 nm airglow emissions for wind retrieval of mesospheric and thermospheric atmosphere using a method based on the convolution of the source profile and instrumental function. Based on the instrument, wind velocities were retrieved using another retrieval method but improved in both noise reduction and choice of interference fringes, which can reduce the disturbance of bad fringes and advance the retrieval precision. The retrieval results were subsequently compared with the FPI wind products, and good agreement was found between them. The averaged deviations of wind velocities between the two retrieval methods depend on airglow intensity with 5.7 m/s for 892.0 nm emission, 6.18 m/s for 630.0 nm emission, and 3.66 m/s for 557.7 nm emission, respectively. Then, a new method was proposed for error calculation by considering the influence of airglow intensity, CCD dark noise, background emissions, and data processing, which can steadily evaluate the precision and reliability of wind retrieval. The relationships between errors derived from the two retrieval methods and airglow intensity were compared and analyzed. It is found that the variation of errors is inversely correlated with the variation of airglow intensity.

  10. 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

  11. Improved temperature retrieval methods for the validation of a hydrodynamic simulation of a partially frozen power plant cooling lake

    NASA Astrophysics Data System (ADS)

    Casterline, May V.; Salvaggio, Carl; Garrett, Alfred J.; Bartlett, Brent D.; Faulring, Jason W.; Salvaggio, Philip S.

    2010-05-01

    The ALGE code is a hydrodynamic model developed by Savannah River National Laboratory (SRNL) to derive the power output levels of an electric generation facility from observing the associated cooling pond with an aerial imaging platform. Over the past two years work has been completed to extend the capabilities of the model to incorporate snow and ice as possible phenomena in the modeled environment. In order to validate the extension of the model, intensive ground truth data as well as high-resolution aerial infrared imagery were collected during the winters of 2008-2009 and 2009-2010, for a combined eight months of data collection. Due to the harsh and extreme environmental conditions automatic data collection instruments were designed and deployed. Based on experience gained during the first collection season and equipment design failures, overhauls in the design and operation of the automated data collection buoys were performed. In addition, a more thorough and robust twofold calibration technique was implemented within the aerial imaging chain to assess the accuracy of the retrieved surface temperatures. By design, the calibration method employed in this application uses ground collected, geolocated water surface temperatures and in-flight blackbody imagery to produce accurate temperature maps of the pond in interest. A sensitivity analysis was implemented within the data reduction technique to produce accurate sensor reaching temperature values using designed equipment and methods for temperature retrieval at the water's surface.

  12. 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.

  13. 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.

  14. A content based video retrieval method for surveillance and forensic applications

    NASA Astrophysics Data System (ADS)

    Vadakkeveedu, Kalyan; Xu, Peng; Fernandes, Ronald; Mayer, Richard J.

    2007-04-01

    The advances in video surveillance technology have lead to the proliferation of surveillance video cameras for the purposes of viewing areas of interest. Counter terrorism and surveillance applications require video forensics capabilities like querying and searching video data for events, people or objects of interest. A human analyst may accurately spot a suspicious activity in a small segment of video. However, due to the large volume of data collected in real-time video surveillance, it is impractical for human analysts to watch or tag the entire video collected as this can lead to human errors, lower throughput and inconsistencies in the level of scrutiny. In this paper, we introduce an ontology-based video retrieval approach, which represents videos with object ontologies and event ontologies, and annotates videos accordingly. We also describe a user-friendly interface for querying surveillance videos using event dictionaries. Our approach leverages the capabilities of ontologies in specifying knowledge at different levels, and, in this way, provides flexibility to a user while forming a query. It is also capable of detecting undefined events such as not previously conceived abnormal events.

  15. 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.

  16. Determining similarity in histological images using graph-theoretic description and matching methods for content-based image retrieval in medical diagnostics

    PubMed Central

    2012-01-01

    Background Computer-based analysis of digitalized histological images has been gaining increasing attention, due to their extensive use in research and routine practice. The article aims to contribute towards the description and retrieval of histological images by employing a structural method using graphs. Due to their expressive ability, graphs are considered as a powerful and versatile representation formalism and have obtained a growing consideration especially by the image processing and computer vision community. Methods The article describes a novel method for determining similarity between histological images through graph-theoretic description and matching, for the purpose of content-based retrieval. A higher order (region-based) graph-based representation of breast biopsy images has been attained and a tree-search based inexact graph matching technique has been employed that facilitates the automatic retrieval of images structurally similar to a given image from large databases. Results The results obtained and evaluation performed demonstrate the effectiveness and superiority of graph-based image retrieval over a common histogram-based technique. The employed graph matching complexity has been reduced compared to the state-of-the-art optimal inexact matching methods by applying a pre-requisite criterion for matching of nodes and a sophisticated design of the estimation function, especially the prognosis function. Conclusion The proposed method is suitable for the retrieval of similar histological images, as suggested by the experimental and evaluation results obtained in the study. It is intended for the use in Content Based Image Retrieval (CBIR)-requiring applications in the areas of medical diagnostics and research, and can also be generalized for retrieval of different types of complex images. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1224798882787923. PMID:23035717

  17. [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

  18. 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.

  19. Expression of chimeric antigen receptors in natural killer cells with a regulatory-compliant non-viral method

    PubMed Central

    Li, Linhong; Liu, Linda N; Feller, Stephanie; Allen, Cornell; Shivakumar, Rama; Fratantoni, Joseph; Wolfraim, Lawrence A.; Fujisaki, Hiroyuki; Campana, Dario; Chopas, Nicholas; Dzekunov, Sergey; Peshwa, Madhusudan

    2009-01-01

    Natural killer1 cells hold promise for cancer therapy. NK cytotoxicity can be enhanced by expression of chimeric antigen receptors that re-direct specificity toward target cells by engaging cell surface molecules expressed on target cells. We developed a regulatory-compliant, scalable non-viral approach to engineer NK cells to be target-specific based on transfection of mRNA encoding chimeric receptors. Transfection of eGFP mRNA into ex vivo expanded NK cells (N=5) or purified unstimulated NK cells from peripheral blood (N=4) resulted in good cell viability with eGFP expression in 85% ± 6% and 86% ± 4%, 24 hours after transfection, respectively. An mRNA encoding a receptor directed against CD19 (anti-CD19-BB-z) was also transfected into NK cells efficiently. Ex vivo expanded and purified unstimulated NK cells expressing anti-CD19-BB-z exhibited enhanced cytotoxicity against CD19+ target cells resulting in ≥80% lysis of acute lymphoblastic leukemia and B-lineage chronic lymphocytic leukemia cells at effector target ratios lower than 10:1. The target-specific cytotoxicity for anti-CD19-BB-z mRNA-transfected NK cells was observed as early as 3 hours after transfection and persisted for up to 3 days. The method described here should facilitate the clinical development of NK-based antigen-targeted immunotherapy for cancer. PMID:19745843

  20. Immunonucleochemistry: a new method for in situ detection of antigens in the nucleus of cells in culture

    PubMed Central

    Lee, HyunSook; Park, Sung Dong; Seog, Dae-Hyun

    2010-01-01

    The advancement of immunocytochemistry (ICC) allows one to observe detailed spatial distribution of cellular antigens, but, with some limitations. Using conventional ICC, it is difficult to distinguish the nuclear localization from cytoplasm, as two large subcellular compartments overlap on the z-axis. In this study, we have investigated whether in situ immunostaining of ‘naked’ nuclei could provide an unambiguous method for detection of nuclear antigens. We have designed a protocol that efficiently lyses plasmalemma, while keeping the nuclear envelope intact. The optimal condition for lysing the plasmalemma was 0.5% Nonidet P-40 for 5 min in both neuronal and non-neuronal cultured cells. Using this protocol, we could unambiguously isolate nuclear from cytoplasmic ICC signals. Since the present protocol has been designed for immunostaining of ‘naked’ nuclei from cultured or isolated cells, we have coined a new term to refer to this procedure as ‘immunonucleochemistry’ (‘INC’ for abbreviation). PMID:20383580

  1. New Method To Generate Enzymatically Deficient Clostridium difficile Toxin B as an Antigen for Immunization

    PubMed Central

    Genth, Harald; Selzer, Jörg; Busch, Christian; Dumbach, Jürgen; Hofmann, Fred; Aktories, Klaus; Just, Ingo

    2000-01-01

    The family of the large clostridial cytotoxins, encompassing Clostridium difficile toxins A and B as well as the lethal and hemorrhagic toxins from Clostridium sordellii, monoglucosylate the Rho GTPases by transferring a glucose moiety from the cosubstrate UDP-glucose. Here we present a new detoxification procedure to block the enzyme activity by treatment with the reactive UDP-2′,3′-dialdehyde to result in alkylation of toxin A and B. Alkylation is likely to occur in the catalytic domain, because the native cosubstrate UDP-glucose completely protected the toxins from inactivation and the alkylated toxin competes with the native toxin at the cell receptor. Alkylated toxins are good antigens resulting in antibodies recognizing only the C-terminally located receptor binding domain, whereas formaldehyde treatment resulted in antibodies recognizing both the receptor binding domain and the catalytic domain, indicating that the catalytic domain is concealed under native conditions. Antibodies against the native catalytic domain (amino acids 1 through 546) and those holotoxin antibodies recognizing the catalytic domain inhibited enzyme activity. However, only antibodies against the receptor binding domain protected intact cells from the cytotoxic activity of toxin B, whereas antibodies against the catalytic domain were protective only when inside the cell. PMID:10678912

  2. An automatic Planetary Boundary Layer height retrieval method with compact EZ backscattering Lidar in the frame of ICOS campaign

    NASA Astrophysics Data System (ADS)

    Loaec, S.; Lolli, S.; Sauvage, L.; Boquet, M.; Xueref-Remy, I.

    2009-12-01

    Bigger strongly urbanized cities in the world are often exposed to atmospheric pollution events. To understand the chemical and physical processes that are taking place in these areas it is necessary to describe correctly the Planetary Boundary Layer (PBL) dynamics and the PBL height evolution. For these proposals, a compact and rugged eye safe UV Lidar, the EZLIDAR™, was developed together by CEA/LMD and LEOSPHERE (France) to study and investigate structural and optical properties of clouds and aerosols and PBL time evolution. EZLIDAR™ has been validated by different remote and in-situ instruments as MPL Type-4 Lidar manufactured by NASA at ARM/SGP site or the LNA (Lidar Nuage Aerosol) at the Laboratoire de Metereologie Dynamique LMD (France) and during several intercomparison campaigns. EZLIDAR™ algorithm retrieves automatically the PBL height in real-time. The method is based on the detection of the slope of the signal linked to a sharp change in concentration of the aerosols. Once detected, the different layers are filtered on a 15mn sample and classified between nocturnal, convective or residual layer, depending on the time and date. This method has been validated against those retrieved by the algorithm STRAT from data acquired at IPSL, France, showing 95% of correlation. In this paper are presented the results of the intercomparison campaign that took place in Orleans, France and Mace Head, Ireland in the framework of ICOS (Integrated Carbon Observation System) project, where the EZ Lidar™ worked under all weather conditions, clear sky, fog, low clouds, during the whole month of October 2008. Moreover, thanks to its 3D scanning capability, the EZLIDAR was able to provide the variability of the PBL height around the site, enabling the scientists to estimate the flux intensities that play a key role in the radiative transfer budget and in the atmospheric pollutants dispersion.

  3. Localization of hepatitis B surface antigen in conventional paraffin sections of the liver. Comparison of immunofluorescence, immunoperoxidase, and orcein staining methods with regard to their specificity and reliability as antigen marker.

    PubMed Central

    Nayak, N. C.; Sachdeva, R.

    1975-01-01

    Hepatitis B antigen (HBAg) has been demonstrated in conventional formalin-fixed paraffin-embedded liver tissue by peroxidase and fluorescent immunostaining as well as by orcein. Complete locational and morphologic identity is seen between material stained by specific immunologic methods and by orcein. The antigen is restricted to the cytoplasm and is generally observed in the hepatocyte; it is present in three morphologic forms. Certain morphologic forms can even be identified in hematoxylin and eosin-stained tissue. Results of immunostaining procedures indicate that the antigen demonstrated in this study consists entirely of surface coat of hepatitis B virus (HBsAg). This seems to be the only component revealed by orcein staining. The latter is considered to be a good marker of the surface antigen and to have certain advantages over immunostaining. It is suggested that suitability of conventional paraffin sections for the detection of HBAg has wide and important implications. Images Figures 1-5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 PMID:55076

  4. 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.

  5. A neural network method for land surface temperature retrieval from AMSR-E passive microwave data over the Tibetan Plateau

    NASA Astrophysics Data System (ADS)

    Gao, C. X.; Qiu, S.; Wu, H.; Jiang, X. G.; Li, Z. L.; Huo, H. Y.

    2012-04-01

    The Tibetan Plateau is well known both for its high altitude and unique geographical features, and has been identified to be critical in regulating the Asia monsoon climate and hydrological cycle. The presence of permafrost and seasonal frozen ground play an important role in determining the nature of Tibetan land and atmosphere interactions. Land surface temperature (LST) is the link between soil-vegetation-atmosphere fluxes and soil water content through the energy water balance, and can be used as an indicator of soil moisture dynamics and for partitioning between sensible and latent heat. In this study, the LSTs over the Tibetan Plateau are retrieved from advanced microwave scanning radiometer-earth (AMSR-E) passive microwave data combined with infrared LST measurements (MODIS LST) onboard the same platform, Aqua satellite, using a generalized regression neural network method. Because of the difficulties in obtaining representative in-situ LST measurements at AMSR-E pixel scale, the MODIS LST is taken as actual ground measurements. To make the method suitable for more situations, clear-sky and cloudy brightness temperatures in AMSR-E channels are simulated under various atmospheric and surface conditions with the aid of the monochromatic radiative transfer model and the advances integral equation model, and are integrated with the measured AMSR-E brightness temperatures and MODIS LSTs to learn the neural network. The results show that the retrieved LST from AMSR-E data in channels 23.8V, 36.5H, 36.5V, 89.0V and 89.0H GHz (V: vertical polarization and H: horizontal polarization) gives the minimal root mean square error (RMSE), approximately 4.5 K, and that more than 73% of errors are within 4 K. In addition, a new group of LST (denoted as AMSR-E LST1) is derived with a single channel method from the same AMSR-E data in channel 37 GHz using a linear relation and is evaluated with MODIS LST. It is noted that there are significant differences between AMSR-E LST1

  6. 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.

  7. An Efficient Method for the Retrieval of Objects by Topological Relations in Spatial Database Systems.

    ERIC Educational Resources Information Center

    Lin, P. L.; Tan, W. H.

    2003-01-01

    Presents a new method to improve the performance of query processing in a spatial database. Experiments demonstrated that performance of database systems can be improved because both the number of objects accessed and number of objects requiring detailed inspection are much less than those in the previous approach. (AEF)

  8. Potential of a spectroscopic measurement method using adding-doubling to retrieve the bulk optical properties of dense microalgal media.

    PubMed

    Bellini, Sarah; Bendoula, Ryad; Latrille, Eric; Roger, Jean-Michel

    2014-01-01

    In the context of algal mass cultivation, current techniques used for the characterization of algal cells require time-consuming sample preparation and a large amount of costly, standard instrumentation. As the physical and chemical properties of the algal cells strongly affect their optical properties, the optical characterization is seen as a promising method to provide an early diagnosis in the context of mass cultivation monitoring. This article explores the potential of a spectroscopic measurement method coupled with the inversion of the radiative transfer theory for the retrieval of the bulk optical properties of dense algal samples. Total transmittance and total reflectance measurements were performed over the 380-1020 nm range on dense algal samples with a double integrating sphere setup. The bulk absorption and scattering coefficients were thus extracted over the 380-1020 nm range by inverting the radiative transfer theory using inverse-adding-doubling computations. The experimental results are presented and discussed; the configuration of the optical setup remains a critical point. The absorption coefficients obtained for the four samples of this study appear not to be more informative about pigment composition than would be classical methods in analytical spectroscopy; however, there is a real added value in measuring the reduced scattering coefficient, as it appears to be strongly correlated to the size distribution of the algal cells. PMID:25198389

  9. 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.

  10. 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. PMID:25604799

  11. A simple and novel method for retrieval of Pasteurellaceae from swab samples collected in the field.

    PubMed

    Hansen, Mie J; Bertelsen, Mads F; Dietz, Rune; Sonne, Christian; Bojesen, Anders M

    2013-10-01

    Traditionally it has been difficult or impossible to collect and preserve bacterial samples of especially fastidious bacteria in mixed primary cultures, unless the samples could be transported to a laboratory within approximately 24 h. Therefore, a simple novel method for preserving swab samples until bacterial isolation can be completed in the laboratory was developed and evaluated. Pasteurellaceae bacteria were used as a representative for fastidious bacteria. A 7.5% glucose serum medium was used as freeze medium. Swab samples were soaked in the medium a maximum of 2 h after collection and stored at -20°C. As a control study, 15 samples were collected from the oral cavity of a captive brown bear. One was immediately plated, while the remaining 12 swabs were stored at -20°C for 7 days and multiples of 30 days up to 330 days prior to plating. Two samples were stored without the medium for 7 and 30 days prior to plating. From a field setting in Greenland, eight polar bear samples were collected and subsequently stored for 240 to 259 days at -20°C before incubation. Pasteurellaceae bacteria were isolated and genotyped from all samples stored in the freeze medium, indicating that the medium enabled the bacteria to survive for at least 330 days at -20°C. The 100% recovery of target organisms in the polar bear samples even following lengthy storage and transport demonstrates that the method is very useful under remote field conditions. PMID:23897719

  12. 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.

  13. 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.

  14. Fast method of retrieving the asymmetry factor and scattering albedo from the maximum time-resolved reflectance of participating media.

    PubMed

    Qi, Hong; Ren, Ya-Tao; Chen, Qin; Ruan, Li-Ming

    2015-06-01

    This research presents a parametric study of the time-resolved hemispherical reflectance of a semi-infinite plane-parallel slab of homogeneous, nonemitting, absorbing, and anisotropic scattering medium exposed to a collimated Gaussian pulse. The one-dimensional transient radiative transfer equation was solved by using the finite volume method. The internal reflection at the medium-air interface caused by the mismatch of the refractive indices was considered. In particular, this work focused on the maximum diffuse hemispherical reflectance. Three different optical regions were identified according to the dimensionless pulsewidth βctp. The correlation between the normalized maximum hemispherical reflectance and βctp was conformed to the Boltzmann function. The coefficients in the correlating functions of the match and mismatch refractive index cases were fitted as polynomial fitting functions of the single scattering albedo ω and Henyey-Greenstein asymmetric factor g. Thus, ω and g can be simultaneously reconstructed by the semi-empirical correlations without solving the forward model. In conclusion, the proposed method can potentially retrieve the asymmetry factor and single scattering albedo of participating media accurately and efficiently. PMID:26192689

  15. 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)

  16. 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.

  17. The influence of sterilization method on articular surface damage of retrieved cruciate-retaining tibial inserts.

    PubMed

    Greulich, Matthew T; Roy, Marcel E; Whiteside, Leo A

    2012-06-01

    This observational study was designed to determine the importance of sterilization method and insert thickness as predictors of articular damage of cruciate-retaining polyethylene components used in total knee arthroplasty. Ninety-nine explanted tibial inserts were evaluated for surface damage. Severe damage modes were observed in 36 of 52 of γ-irradiated inserts but none of those sterilized by ethylene oxide. Articular damage significantly correlated to time in vivo but not to insert thickness. Inserts sterilized by ethylene oxide gas in gas-permeable packaging exhibited a significantly lower damage accumulation rate compared with inserts sterilized by γ radiation and stored in air or an inert environment. γ irradiation and storage in argon instead of air reduced the frequency of severe damage such as delamination but not the overall damage rate. PMID:22177798

  18. 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

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

    PubMed

    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

  20. Human factors analysis and design methods for nuclear waste retrieval systems. Volume IV. Computerized Event-Tree Analysis Technique

    SciTech Connect

    Deretsky, Z.; Casey, S.M.

    1980-08-01

    This document contains a program listing and brief description of CETAT, the Computerized Event-Tree Analysis Technique. CETAT was developed to serve as a tool for developing, organizing, and analyzing operator-initiated event probabilities associated with the tasks required during the retrieval of spent fuel canisters. 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.

  1. Markov Chain Method for Radiative Transfer Modeling: A Case Study of Aerosol/Surface Retrieval using AirMSPI Measurements

    NASA Astrophysics Data System (ADS)

    Xu, F.; Diner, D. J.; Davis, A. B.; Latyshev, S.; Garay, M. J.; Kalashnikova, O.; Ge, C.; Wang, J.

    2013-12-01

    A vector Markov chain (MarCh) radiative transfer (RT) code developed at JPL that includes forward modeling of radiance and polarization fields and linearization (analytical estimation of Jacobians) was incorporated into an aerosol and surface retrieval package for a plane-parallel atmosphere/surface system. The RT computation by MarCh is based on matrix operations. To improve the code's computational efficiency, the forward model is currently undergoing acceleration through the exploration of different strategies for matrix operation and inversion, including numerical optimization, multi-threading/multi-processing techniques on a CPU. Implementation on a graphics processing unit (GPU) is also planned. Following a benchmarking study of the forward model, the performance of MarCh in aerosol and surface retrieval is being tested. With an optimized algorithm, we started from aerosol optical depth and surface retrieval using imagery acquired by Airborne Multiangle SpectroPolarimetric Imager (AirMSPI) over Fresno, CA. Aerosol properties including concentration and size distribution of different species provided by the Weather Research and Forecasting (WRF)-Chem model were used to constrain the retrieval and reduce the parameter space. The assumptions of spectral invariance in the angular shape of surface bidirectional reflectance factors (BRFs) and the magnitude of polarized surface BRFs were tested. The aerosol and surface properties are then relaxed in a stepwise way to refine the aerosol retrieval results and enable comparison with independent retrievals obtained from a collocated AErosol RObotic NETwork (AERONET) station.

  2. 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.

  3. 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.

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

    PubMed

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

    2014-03-21

    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. PMID:24584079

  5. Comparison of diffuse sky irradiance calculation methods and effect on surface reflectance retrieval from an automated radiometric calibration test site

    NASA Astrophysics Data System (ADS)

    Leisso, Nathan; Czapla-Myers, Jeffrey

    2011-10-01

    The Remote Sensing Group (RSG) at the University of Arizona is currently refining an automated system for the absolute radiometric calibration of earth-observing sensors. The Radiometric Calibration Test Site (RadCaTS) relies on semi-permanent instrumentation at the Railroad Valley (RRV) test site to collect data from which surface reflectance and an atmospheric characterization is determined. Multispectral surface reflectance is determined from calibrated ground viewing radiometers and assimilated to determine the hyperspectral reflectance used in radiative transfer calculations. The reflectance retrieval algorithm relies on an accurate determination of the diffuse sky irradiance for the time of interest. Currently, diffuse sky irradiance is modeled using the atmospheric characterization as input into MODTRAN5. This work investigates the accuracy of the diffuse sky modeling by comparing modeled results to measurements made at the test site. Diffuse sky irradiance from several alternative methods are also presented. Surface reflectance is computed and compared to in-situ measurements taken with a portable spectoradiometer.

  6. [Detection of antigen-antibody interaction of human adenovirus by the method of surface plasmon resonance].

    PubMed

    Nosach, L M; Boltovets', P M; Povnytsia, O Iu; Zhovnovata, V L; Zakharenko, O M; Snopok, B A; Shyrshov, Iu M; Diachenko, N S

    2005-01-01

    A possibility to detect adenoviral protein--hexon, using specific antibodies by surface plasmon resonance (SPR) was demonstrated. The hexon of the human adenovirus 2 (Ad2) binds to antibodies immobilized on the sensor surface treated by KNCS and protein A Staphylococcus aureus. The specificity of antihexon antibodies was demonstrated by indirect method of fluorescent antibodies (MFA) and cellular variant of the immunoassay (cELISA). PMID:16250237

  7. 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

  8. 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.

  9. 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.

  10. Retrievable Inferior Vena Cava Filters: Factors that Affect Retrieval Success

    SciTech Connect

    Geisbuesch, Philipp Benenati, James F.; Pena, Constantino S.; Couvillon, Joseph; Powell, Alex; Gandhi, Ripal; Samuels, Shaun; Uthoff, Heiko

    2012-10-15

    Purpose: To report and analyze the indications, procedural success, and complications of retrievable inferior vena cava filters (rIVCF) placement and to identify parameters that influence retrieval attempt and failure. Methods: Between January 2005 and December 2010, a total of 200 patients (80 men, median age 67 years, range 11-95 years) received a rIVCF with the clinical possibility that it could be removed. All patients with rIVCF were prospectively entered into a database and followed until retrieval or a decision not to retrieve the filter was made. A retrospective analysis of this database was performed. Results: Sixty-one percent of patients had an accepted indication for filter placement; 39% of patients had a relative indication. There was a tendency toward a higher retrieval rate in patients with relative indications (40% vs. 55%, P = 0.076). Filter placement was technically successful in all patients, with no procedure-related mortality. The retrieval rate was 53%. Patient age of >80 years (odds ratio [OR] 0.056, P > 0.0001) and presence of malignancy (OR 0.303, P = 0.003) was associated with a significantly reduced probability for attempted retrieval. Retrieval failure occurred in 7% (6 of 91) of all retrieval attempts. A time interval of > 90 days between implantation and attempted retrieval was associated with retrieval failure (OR 19.8, P = 0.009). Conclusions: Patient age >80 years and a history of malignancy are predictors of a reduced probability for retrieval attempt. The rate of retrieval failure is low and seems to be associated with a time interval of >90 days between filter placement and retrieval.

  11. Approach for selecting boundary value to retrieve Mie-scattering lidar data based on segmentation and two-component fitting methods.

    PubMed

    Mao, Feiyue; Wang, Wei; Min, Qilong; Gong, Wei

    2015-06-01

    Fernald method is regarded as the standard method for retrieving lidar data, but the retrieval can be performed only when a boundary value is given. Generally, we can select clear atmosphere above the tropopause as a reference to determine the boundary value, but we need to use the slope method to fit the boundary value when the detecting range is lower than the tropopause. The slope method involves significant uncertainty because this algorithm is based on two hypotheses: one is that aerosol vertical distribution is homogeneous, and the other is that either molecule or aerosol components exist in the atmosphere. To reduce the uncertainty, we proposed a new approach, which segments a signal into "uniform" sub-signals to avoid the first hypothesis, and then uses nonlinear two-component fitting to avoid the second one. Compared with the approach based on the slope method, the new approach obtained more accurate boundary values and retrieving results for both of the simulated and real signals. Thus the automatic segmentation algorithm and the two-component fitting method are useful for determining the reference bin and boundary values when the effective detecting range of lidar is lower than the tropopause. PMID:26072885

  12. 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

  13. Comparing the Precision of Information Retrieval of MeSH-Controlled Vocabulary Search Method and a Visual Method in the Medline Medical Database

    PubMed Central

    Hariri, Nadjla; Ravandi, Somayyeh Nadi

    2014-01-01

    Background: Medline is one of the most important databases in the biomedical field. One of the most important hosts for Medline is Elton B. Stephens CO. (EBSCO), which has presented different search methods that can be used based on the needs of the users. Visual search and MeSH-controlled search methods are among the most common methods. The goal of this research was to compare the precision of the retrieved sources in the EBSCO Medline base using MeSH-controlled and visual search methods. Methods: This research was a semi-empirical study. By holding training workshops, 70 students of higher education in different educational departments of Kashan University of Medical Sciences were taught MeSH-Controlled and visual search methods in 2012. Then, the precision of 300 searches made by these students was calculated based on Best Precision, Useful Precision, and Objective Precision formulas and analyzed in SPSS software using the independent sample T Test, and three precisions obtained with the three precision formulas were studied for the two search methods. Results: The mean precision of the visual method was greater than that of the MeSH-Controlled search for all three types of precision, i.e. Best Precision, Useful Precision, and Objective Precision, and their mean precisions were significantly different (P <0.001). Sixty-five percent of the researchers indicated that, although the visual method was better than the controlled method, the control of keywords in the controlled method resulted in finding more proper keywords for the searches. Fifty-three percent of the participants in the research also mentioned that the use of the combination of the two methods produced better results. Conclusion: For users, it is more appropriate to use a natural, language-based method, such as the visual method, in the EBSCO Medline host than to use the controlled method, which requires users to use special keywords. The potential reason for their preference was that the visual

  14. Osteosarcoma Microenvironment: Whole-Slide Imaging and Optimized Antigen Detection Overcome Major Limitations in Immunohistochemical Quantification

    PubMed Central

    Kunz, Pierre; Fellenberg, Jörg; Moskovszky, Linda; Sápi, Zoltan; Krenacs, Tibor; Poeschl, Johannes; Lehner, Burkhard; Szendrõi, Miklos; Ewerbeck, Volker; Kinscherf, Ralf; Fritzsching, Benedikt

    2014-01-01

    Background In osteosarcoma survival rates could not be improved over the last 30 years. Novel biomarkers are warranted to allow risk stratification of patients for more individual treatment following initial diagnosis. Although previous studies of the tumor microenvironment have identified promising candidates, novel biomarkers have not been translated into routine histopathology. Substantial difficulties regarding immunohistochemical detection and quantification of antigens in decalcified and heterogeneous osteosarcoma might largely explain this translational short-coming. Furthermore, we hypothesized that conventional hot spot analysis is often not representative for the whole section when applied to heterogeneous tissues like osteosarcoma. We aimed to overcome these difficulties for major biomarkers of the immunovascular microenvironment. Methods Immunohistochemistry was systematically optimized for cell surface (CD31, CD8) and intracellular antigens (FOXP3) including evaluation of 200 different antigen retrieval conditions. Distribution patterns of these antigens were analyzed in formalin-fixed and paraffin-embedded samples from 120 high-grade central osteosarcoma biopsies and computer-assisted whole-slide analysis was compared with conventional quantification methods including hot spot analysis. Results More than 96% of osteosarcoma samples were positive for all antigens after optimization of immunohistochemistry. In contrast, standard immunohistochemistry retrieved false negative results in 35–65% of decalcified osteosarcoma specimens. Standard hot spot analysis was applicable for homogeneous distributed FOXP3+ and CD8+ cells. However, heterogeneous distribution of vascular CD31 did not allow reliable quantification with hot spot analysis in 85% of all samples. Computer-assisted whole-slide analysis of total CD31- immunoreactive area proved as the most appropriate quantification method. Conclusion Standard staining and quantification procedures are not

  15. 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.

  16. Golden Retrievers.

    ERIC Educational Resources Information Center

    Christensen, Deborah

    1999-01-01

    Provides a basic definition of metadata, including the usefulness of metatags for online information retrieval and documentation. Defines the elements of the Dublin Core, the next level of metadata. Discusses how librarians can take advantage of metadata. Describes the Gateway to Educational Materials (GEM) Project whose goal is to use metadata to…

  17. Demonstration of retrieval methods for Westinghouse Hanford Corporation by EPW Industrial Services Incorporated, trial number 2, April 30, 1996

    SciTech Connect

    1996-10-01

    Westinghouse Hanford Company 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. Previous trials run by MPW for Westinghouse Hanford Company (report dated October 20, 1995) resulted in difficulty breaking up the simulant using three approaches, with pressures to I 0,000 psi and flow rates to 56 gpm. The saltcake sirnulant was extremely hard, with a tensile strength similar to concrete. Westinghouse Hanford proposed a second set of trials utilizing a range of four sirnulants to attempt to bracket the capability of the I 0,000 psi waterblast stream. This set of trials had one simulant similar to the soft sludge previously trialed, two similar to the hard saltcake but with a lower strength, and one with a coarse rock-salt in a saltcake matrix, which is quite low in strength. Under this proposal, MPW would attempt to dislodge the four different simulants us@@ng two methods, for a total of eight pans. Each pan would be 4-foot square x I- 1/2-foot deep. The approaches would be as follows: A. Rotary tooling approaching straight down, with two triangle nozzles, each at a nominal 12.5 gpm at I 0,000 psi, at a 45-degree angle. B. Straight in to the exposed edge of the material with an articulated ``water cannon`` -with a triangle nozzle rated at approximately 25 gpm.

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

    NASA Astrophysics Data System (ADS)

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

    2012-07-01

    A new Rapid Retrieval of upwelling fluxes 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. Two shortwave retrievals are presented and discussed: the first one based on a multilinear parameterisation and the second one based on a neural network. The neural network method is shown to be slightly more accurate and simpler to apply for the desired purpose. 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.

  19. 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

  20. A partial least square regression method to quantitatively retrieve soil salinity using hyper-spectral reflectance data

    NASA Astrophysics Data System (ADS)

    Qu, Yonghua; Jiao, Siong; Lin, Xudong

    2008-10-01

    Hetao Irrigation District located in Inner Mongolia, is one of the three largest irrigated area in China. In the irrigational agriculture region, for the reasons that many efforts have been put on irrigation rather than on drainage, as a result much sedimentary salt that usually is solved in water has been deposited in surface soil. So there has arisen a problem in such irrigation district that soil salinity has become a chief fact which causes land degrading. Remote sensing technology is an efficiency way to map the salinity in regional scale. In the principle of remote sensing, soil spectrum is one of the most important indications which can be used to reflect the status of soil salinity. In the past decades, many efforts have been made to reveal the spectrum characteristics of the salinized soil, such as the traditional statistic regression method. But it also has been found that when the hyper-spectral reflectance data are considered, the traditional regression method can't be treat the large dimension data, because the hyper-spectral data usually have too higher spectral band number. In this paper, a partial least squares regression (PLSR) model was established based on the statistical analysis on the soil salinity and the reflectance of hyper-spectral. Dataset were collect through the field soil samples were collected in the region of Hetao irrigation from the end of July to the beginning of August. The independent validation using data which are not included in the calibration model reveals that the proposed model can predicate the main soil components such as the content of total ions(S%), PH with higher determination coefficients(R2) of 0.728 and 0.715 respectively. And the rate of prediction to deviation(RPD) of the above predicted value are larger than 1.6, which indicates that the calibrated PLSR model can be used as a tool to retrieve soil salinity with accurate results. When the PLSR model's regression coefficients were aggregated according to the

  1. 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.

  2. 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

  3. 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. PMID:12396180

  4. A New Method to Retrieve the Data Requirements of the Remote Sensing Community – Exemplarily Demonstrated for Hyperspectral User Needs

    PubMed Central

    Nieke, Jens; Reusen, Ils

    2007-01-01

    User-driven requirements for remote sensing data are difficult to define, especially details on geometric, spectral and radiometric parameters. Even more difficult is a decent assessment of the required degrees of processing and corresponding data quality. It is therefore a real challenge to appropriately assess data costs and services to be provided. In 2006, the HYRESSA project was initiated within the framework 6 programme of the European Commission to analyze the user needs of the hyperspectral remote sensing community. Special focus was given to finding an answer to the key question, “What are the individual user requirements for hyperspectral imagery and its related data products?”. A Value-Benefit Analysis (VBA) was performed to retrieve user needs and address open items accordingly. The VBA is an established tool for systematic problem solving by supporting the possibility of comparing competing projects or solutions. It enables evaluation on the basis of a multidimensional objective model and can be augmented with expert's preferences. After undergoing a VBA, the scaling method (e.g., Law of Comparative Judgment) was applied for achieving the desired ranking judgments. The result, which is the relative value of projects with respect to a well-defined main objective, can therefore be produced analytically using a VBA. A multidimensional objective model adhering to VBA methodology was established. Thereafter, end users and experts were requested to fill out a Questionnaire of User Needs (QUN) at the highest level of detail - the value indicator level. The end user was additionally requested to report personal preferences for his particular research field. In the end, results from the experts' evaluation and results from a sensor data survey can be compared in order to understand user needs and the drawbacks of existing data products. The investigation – focusing on the needs of the hyperspectral user community in Europe – showed that a VBA is a

  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. Isolation of potentially useful antigens from cyathostomin third-stage larvae by using a fast protein liquid chromatography one-step method.

    PubMed

    Paz-Silva, A; Francisco, R; Rodríguez, I; Francisco, I; Cazapal-Monteiro, C F; Arias, M S; Suárez, J L; Sánchez-Andrade, R

    2011-09-01

    Three major protein complexes (51, 29, and 15 kDa, named P1 to P3, respectively) were resolved by gel filtration of the excretory/secretory antigens collected from a mixture of horse cyathostomin third-stage larvae (L3s). The potential application for the detection of infected horses was assessed with an enzyme-linked immunosorbent assay (ELISA) by the comparison of the serological and copromicroscopical results. The value of the area under the receiver operating characteristic (ROC) curve was higher than 0.9 when the three peaks were used. Elevated values (>90%) for the sensitivity, specificity, and the positive-likelihood ratio were also observed for all the antigen complexes. A significant increment in the IgG antibody levels 4 weeks prior to the observation of eggs in the feces of weanlings naturally infected was recorded. Our results indicate that the evaluation of chemotherapy is possible by using immunoenzymatic probes and fast protein liquid chromatography (FPLC)-purified antigens. Data collected in the present investigation indicate that FPLC isolation offers a very helpful one-step method for collecting antigens with diagnostic potential to be employed in immunoenzymatic probes. PMID:21775518

  7. Error rate for HLA-B antigen assignment by serology: implications for proficiency testing and utilization of DNA-based typing methods.

    PubMed

    Bozón, M V; Delgado, J C; Selvakumar, A; Clavijo, O P; Salazar, M; Ohashi, M; Alosco, S M; Russell, J; Yu, N; Dupont, B; Yunis, E J

    1997-10-01

    Until recently, the majority of HLA class I typing has been performed by serology. Expensive commercial typing trays are frequently used for testing non-Caucasian subjects and new strategies using DNA-based methods have been adopted for improving clinical histocompatibility testing results and adapted as supplements in proficiency testing. A double-blind comparison of the typing of HLA-B specificities in 40 samples was carried out between serology and two polymerase chain reaction (PCR) methods, PCR amplification with sequence-specific primers (PCR-SSP) and PCR amplification and subsequent hybridization with sequence-specific oligonucleotide probes (PCR-SSOP). The results demonstrated 22.5% misassignments of HLA-B antigens by serology. There was complete concordance between the results obtained with the two PCR based typing methods. A second panel of 20 donor samples with incomplete or ambiguous serologic results was analyzed by PCR-SSP and SSOP Both PCR methods identified correctly the HLA-B antigens. Our results suggest that more accurate typing results can be achieved by complementing serologic testing with DNA-based typing techniques. The level of resolution for HLA-B antigen assignment can be obtained by this combination of serology and limited DNA-based typing is equivalent to the HLA-B specificities defined by the WHO-HLA Committee. This level of resolution cannot routinely be achieved in clinical histocompatibility testing or in proficiency testing using serologic reagents only. PMID:9349624

  8. 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.

  9. 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.

  10. Adaptive MGS Phase Retrieval

    NASA Technical Reports Server (NTRS)

    Basinger, Scott A.; Bikkannavar, Siddarayappa; Cohen, David; Green, Joseph J.; Lou, John; Ohara, Catherine; Redding, David; Shi, Fang

    2008-01-01

    Adaptive MGS Phase Retrieval software uses the Modified Gerchberg-Saxton (MGS) algorithm, an image-based sensing method that can turn any focal plane science instrument into a wavefront sensor, avoiding the need to use external metrology equipment. Knowledge of the wavefront enables intelligent control of active optical systems.

  11. Dropout Retrieval Programs.

    ERIC Educational Resources Information Center

    Salerno, Anne; Fink, Mary

    This paper describes 15 dropout retrieval programs that have components with potential for helping migrant dropout youth return to an educational program. Each profile contains information on eligibility, identification or recruitment method, funding, services, and contacts. In addition, each program is categorized as to type of sponsoring…

  12. Comparison of Fecal Antigen Detection Using Enzyme Linked Immunosorbent Assay With the Auramine Phenol Staining Method for Diagnosis of Human Cryptosporidiosis

    PubMed Central

    Jafari, Rasool; Maghsood, Amir Hossein; Safari, Marzieh; Latifi, Milad; Fallah, Mohammad

    2015-01-01

    Background: Fecal antigen detection using the enzyme linked immunosorbent assay (ELISA) and oocyst detection using auramine phenol (AP) staining methods, are told to be more sensitive compared to other conventional methods, for diagnosis of cryptosporidiosis. Objectives: The aim of the present study was to evaluate the antigen-detection capacity in the stool specimens using ELISA and oocyst detection by AP staining methods, for the diagnosis of human cryptosporidiosis. Materials and Methods: A total of 228 fecal samples were collected from residents of rural areas of Hamadan, West of Iran. Each fecal sample was divided into two parts, one kept frozen at -20˚C for Ag-capture ELISA and the other in 10% formalin for the AP staining method. Cryptosporidium Ag-detection ELISA procedure was performed according to the manual of the manufacturer. The preserved samples concentrated using the formalin-ether concentration technique were stained with AP and then investigated under florescent microscopy. Results: Eight (3.5%) and three (1.3%) out of 228 fecal samples were positive for Cryptosporidium infection by ELISA and AP staining methods, respectively. Cryptosporidium Ag-detection using ELISA showed an increased frequency of the infection, compared to the AP staining method (P = 0.062). Conclusions: For epidemiological studies and diagnostic purposes of the Cryptosporidium infection, especially in asymptomatic individuals, Ag-detection ELISA is an easy to perform and accurate method, compared to other conventional microscopic methods. PMID:25825642

  13. Epidemiological survey of anti-flea IgE in dogs in Japan by using an antigen-specific IgE quantitative measurement method

    PubMed Central

    Ichikawa, Y.; Beugnet, F.

    2012-01-01

    In Japan, an epidemiological survey was performed in dogs from October to December 2008 by using a quantitative measurement method for antigen-specific IgE towards specific Ctenocephalides felis antigens. 214 dogs from 22 veterinary clinics were included. These clinics were located as follows, from North to South: Hokkaido, Aomori, Fukushima, Tochigi, Saitama, Chiba, Tokyo (Tama-City and Ota-ku), Kanagawa, Gifu, Niigata, Kyoto, Nara, Osaka, Hyogo, Kagawa, Ehime, Hiroshima, Yamaguchi, Fukuoka, Kumamoto and Kagoshima. 110 dogs (51.4%) were seropositive for flea-specific IgE. No differences were associated with gender or breed. This survey confirms that flea infestation in dogs is a common problem in Japan. It especially shows that the infestation also occurs in Northern Japan where fleas are considered uncommon by the vet. PMID:22550629

  14. Transfer of proteins from gels to diazobenzyloxymethyl-paper and detection with antisera: a method for studying antibody specificity and antigen structure.

    PubMed Central

    Renart, J; Reiser, J; Stark, G R

    1979-01-01

    We describe a rapid and very sensitive method for detecting proteins as antigens after their separation in polyacrylamide/agarose composite gels, with or without sodium dodecyl sulfate. The polyacrylamide matrix is crosslinked with a reagent that can be cleaved with periodate or alkali to facilitate transfer of the protein bands to diazobenzyloxymethyl-paper, where they are coupled covalently. Specific proteins are detected by autoradiography after sequential incubation with unfractionated, unlabeled specific antiserum and 125I-labeled protein A from Staphylococcus aureus. Antibody and protein A can be removed with urea and 2-mercaptoethanol, and the same paper can be probed again with a different antiserum. An antiserum specific for the simian virus 40 virion proteins VP3 and VP2 has been prepared; it does not crossreact with VP1, as demonstrated by this method. An antiserum raised in rabbits against simian virus 40-transformed rabbit kidney cells is shown to be directed primarily against a periodate-sensitive moiety present in tumor (T) antigen from infected or transformed cells, whereas an antiserum raised in rabbits against large T antigen purified from lytically infected monkey kidney cells by electrophoresis in the presence of sodium dodecyl sulfate [Lane, D.P. & Robbins, A.K. (1978) Virology 87, 182-193] is directed primarily against determinants that are not sensitive to periodate. Images PMID:91164

  15. Comparative analysis of land surface emissivity retrieval methods and the impact on the land surface temperature based on Landsat-8 thermal infrared data

    NASA Astrophysics Data System (ADS)

    Kan, Zenghui; Liu, Chaoshun; Zhou, Cong; Li, Zhijun

    2015-09-01

    With the increasingly prevalent and far-reaching application of remote sensing, several algorithms have been put forward for land surface temperature retrieval. However, there is still no consensus on the calculation of land surface emissivity (LSE), which is one of the significant parameters in land surface temperature (LST) retrieval. In this paper, two methods of estimating LSE based on thematic mapper data were introduced: Van's empirical formula method and the mixed pixels method. Based on the detailed introduction to Van's empirical formula and the mixed pixels decomposing method in computing surface emissivity, Landsat-8 thermal infrared data and the radiative transfer equation method were used to obtain the land surface temperature in Taihu region. In this paper, atmospheric parameters are based on real-time atmospheric profile to reduce the LST error brought by the atmospheric profile. Two figures were acquired, which represented the LST of Van's empirical formula and the mixed pixels decomposing method respectively. The relationship between land surface temperature and land cover was also studied.

  16. Development of a DNA Microarray Method for Detection and Identification of All 15 Distinct O-Antigen Forms of Legionella pneumophila

    PubMed Central

    Cao, Boyang; Yao, Fangfang; Liu, Xiangqian; Feng, Lu

    2013-01-01

    Legionella is ubiquitous in many environments. At least 50 species and 70 serogroups of the Gram-negative bacterium have been identified. Of the 50 species, 20 are pathogenic, and Legionella pneumophila is responsible for the great majority (approximately 90%) of the Legionnaires' disease cases that occur. Furthermore, of the 15 L. pneumophila serogroups identified, O1 alone causes more than 84% of the Legionnaires' disease cases that occur worldwide. Rapid and reliable assays for the detection and identification of L. pneumophila in water, environmental, and clinical samples are in great demand. L. pneumophila bacteria are traditionally identified by their O antigens by immunological methods. We have recently developed an O serogroup-specific DNA microarray for the detection of all 15 distinct O-antigen forms of L. pneumophila, including serogroups O1 to O15. A total of 35 strains were used to verify the specificity of the microarray, including 15 L. pneumophila O-antigen standard reference strains and seven L. pneumophila clinical isolates as target strains, seven reference strains of other non-pneumophila Legionella species as closely related strains, and six non-Legionella bacterial species as nonrelated strains. The detection sensitivity was 1 ng of genomic DNA or 0.4 CFU/ml in water samples with filter enrichment and plate culturing. This study demonstrated that the microarray allows specific, sensitive, and reproducible detection of L. pneumophila serogroups. To the best of our knowledge, this is the first report of a microarray serotyping method for all 15 distinct O-antigen forms of L. pneumophila. PMID:23974134

  17. Combined megaplex TCR isolation and SMART-based real-time quantitation methods for quantitating antigen-specific T cell clones in mycobacterial infection

    PubMed Central

    Du, George; Qiu, Liyou; Shen, Ling; Sehgal, Probhat; Shen, Yun; Huang, Dan; Letvin, Norman L.; Chen, Zheng W.

    2010-01-01

    Despite recent advances in measuring cellular immune responses, the quantitation of antigen-specific T cell clones in infections or diseases remains challenging. Here, we employed combined megaplex TCR isolation and SMART-based real-time quantitation methods to quantitate numerous antigen-specific T cell clones using limited amounts of specimens. The megaplex TCR isolation covered the repertoire comprised of recombinants from 24 Vβ families and 13 Jβ segments, and allowed us to isolate TCR VDJ clonotypic sequences from one or many PPD-specific IFNγ-producing T cells that were purified by flow cytometry sorting. The SMART amplification technique was then validated for its capacity to proportionally enrich cellular TCR mRNA/cDNA for real-time quantitation of large numbers of T cell clones. SMART amplified cDNA was shown to maintain relative expression levels of TCR genes when compared to unamplified cDNA. While the SMART-based real-time quantitative PCR conferred a detection limit of 10−5 to 10−6 antigen-specific T cells, the clonotypic primers specifically amplified and quantitated the target clone TCR but discriminated other clones that differed by ≥2 bases in the DJ regions. Furthermore, the combined megaplex TCR isolation and SMART-based real-time quantiation methods allowed us to quantitate large numbers of PPD-specific IFNγ-producing T cell clones using as few as 2×106 PBMC collected weekly after mycobacterial infection. This assay system may be useful for studies of antigen-specific T cell clones in tumors, autoimmune and infectious diseases. PMID:16403511

  18. 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

  19. Application of the angular position of the visible horizon for atmospheric trace gases retrieval by MAX-DOAS method

    NASA Astrophysics Data System (ADS)

    Bruchkouski, Ilya; Krasovsky, Alexander; Demin, Victor

    2015-04-01

    Significant impact on the retrieval process of atmospheric trace gases by MAX-DOAS has accuracy of the elevation angle adjustment of the telescope unit. Additional information about the magnitude of the true elevation angles in MAX-DOAS system is very important because a slight change in elevation at angles 0 ° - 5 ° leads to a change in the geometry of the observation that has a strong influence on the measured value (slant column density). For monitoring the state of the atmosphere automated device based on the spectrograph ORIEL MS257 with a cooled CCD Andor Technology, spectral range 411-493 nm, FWHM = 0.5 nm has been constructed. This instrument records the spectrum of scattered sunlight in the range of elevation angles 0 ° - 90 ° within an aperture of 1.3 °. The number of registered spectra per day amounts to 4000. This device passed MAX-DOAS intercomparison campaign in the Max-Planck-Institute for Chemistry (Mainz) for the period 20.06.2013 - 10.09.2013. Procedures of the retrieval of nitrogen dioxide parallel measurements has been performed, the results of comparisons will be presented. Series of data about the angular position of the visible horizon line for two months of observation has been obtained. Using this pattern, corrections can be made in determining the elevation angle of the telescope unit, during the processing of the experimental data by MAX-DOAS.

  20. 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…

  1. Interactive Exploration for Image Retrieval

    NASA Astrophysics Data System (ADS)

    Cord, Matthieu; Philipp-Foliguet, Sylvie; Gosselin, Philippe-Henri; Fournier, Jérôme

    2005-12-01

    We present a new version of our content-based image retrieval system RETIN. It is based on adaptive quantization of the color space, together with new features aiming at representing the spatial relationship between colors. Color analysis is also extended to texture. Using these powerful indexes, an original interactive retrieval strategy is introduced. The process is based on two steps for handling the retrieval of very large image categories. First, a controlled exploration method of the database is presented. Second, a relevance feedback method based on statistical learning is proposed. All the steps are evaluated by experiments on a generalist database.

  2. A new storage and retrieval method to support editing operations in a multi-disk-based video server

    SciTech Connect

    Chien-I Lee; Wei-Pang Yang; Ye-In Chang

    1996-12-31

    Since the storage ordering is assumed the same as the retrieval ordering in all the previous storage placement strategies, there is a requirement of a large amount of file copying or merging operations when users insert/delete some data into/from the media data. The observation is also important for video applications because features, like video editing, require the support of random access on individual video frames. In this paper, we propose a new strategy for the insert/delete operations on continuous media that are striped into multidisks without reorganization of the whole data. From our performance analysis and simulation, the proposed algorithms for insertion/deletion may require only some additional movement cost.

  3. 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.

  4. 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.

    2015-06-01

    The 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 modifications 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, 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 artifacts 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.

  5. 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.

  6. Retrieving aerosol optical depth and type in the boundary layer over land and ocean from simultaneous GOME spectrometer and ATSR-2 radiometer measurements, 1, Method description

    NASA Astrophysics Data System (ADS)

    Holzer-Popp, T.; Schroedter, M.; Gesell, G.

    2002-11-01

    A new aerosol retrieval method called Synergetic Aerosol Retrieval (SYNAER), using simultaneous measurements of the radiometer Along Track Scanning Radiometer (ATSR-2) and the spectrometer Global Ozone Monitoring Experiment (GOME) in the visible and near-infrared spectra, was developed. Both instruments are flown onboard the European Remote Sensing (ERS-2) satellite. SYNAER delivers boundary layer aerosol optical thickness (BLAOT) and aerosol type both over land and over ocean, the latter as BLAOT percentage of six representative components from the Optical Parameters of Aerosols and Clouds (OPAC) data set. The high spatial resolution of ATSR-2 permits accurate cloud detection. It allows BLAOT calculation over automatically selected dark pixels and surface albedo correction for a set of boundary layer aerosol mixtures. After spatial integration and colocation to GOME pixels, these parameters are used to simulate GOME spectra for the same set of aerosol mixtures. A least squares fit of these spectra to the measured and cloud-corrected GOME spectrum chooses the aerosol mixture. First validation studies are presented in part 2 of this paper [, 2002]. The method will be used for the future sensor pairs Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY)/Advanced ATSR (AATSR) on Envisat and GOME-2/Advanced Very High Resolution Radiometer (AVHRR) on METOP. Thus, SYNAER holds the potential to extract a long-term climatological data set.

  7. 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.

  8. A method for eliciting indurated DTH reactions to soluble protein antigens in the flank skin of mice: correlation of visual measurements with 125I-UdR uptake indices.

    PubMed

    Brummer, E; Bhardwaj, N; Lawrence, H S

    1981-01-01

    A new technique for eliciting specific indurated delayed type hypersensitivity (DTH) reactions to soluble protein antigens in the flank skin of mice is reported here. We show that immunization with soluble antigens emulsified in complete Freund's adjuvant emulsion allows elicitation of indurated reactions upon intracutaneous test of sensitized mice with antigen on alum precipitates. With this method it is possible to measure simultaneously the gross induration of the cutaneous DTH reactions and correlate it with the degree of mononuclear cell infiltration as quantitated by the cPM of 125I-UdR uptake in mononuclear cells at biopsied reaction sites and confirmed by histological examination. PMID:7216506

  9. 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 Astrophysics Data System (ADS)

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

    2016-06-01

    The bispectral method retrieves cloud optical thickness (τ) 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 τ and re. In the literature, the retrievals of τ 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 τ 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 τ 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 τ 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

  10. 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

  11. Antigenic sites in carcinoembryonic antigen.

    PubMed

    Hammarstrom, S; Shively, J E; Paxton, R J; Beatty, B G; Larsson, A; Ghosh, R; Bormer, O; Buchegger, F; Mach, J P; Burtin, P

    1989-09-01

    The epitope reactivities of 52 well-characterized monoclonal antibodies (Mabs) against carcinoembryonic antigen from 11 different research groups were studied using competitive solid-phase immunoassays. About 60% of all possible combinations of Mabs as inhibitors and as the primary binding antibody were investigated. The inhibition data were analyzed by a specially developed computer program "EPITOPES" which measures concordance and discordance in inhibition patterns between Mabs. The analysis showed that 43 of the 52 Mabs (83%) could be classified into one of five essentially noninteracting epitope groups (GOLD 1-5) containing between four and 15 Mabs each. The epitopes recognized by the Mabs belonging to groups 1 to 5 were peptide in nature. With one or two possible exceptions non-classifiable Mabs were either directed against carbohydrate epitopes (4 Mabs) or were inactive in the tests used. Within epitope groups GOLD 1, 4, and 5 two partially overlapping subgroups were distinguished. Mabs with a high degree of carcinoembryonic antigen specificity generally belonged to epitope groups GOLD 1 and 3. PMID:2474375

  12. 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

  13. Evaluation of a simple blood culture amplification and antigen detection method for diagnosis of Salmonella enterica serovar typhi bacteremia.

    PubMed

    Castonguay-Vanier, Josée; Davong, Viengmon; Bouthasavong, Latsanyphone; Sengdetka, Davanh; Simmalavong, Manivone; Seupsavith, Amphayvanh; Dance, David A B; Baker, Stephen; Le Thi Phuong, Tu; Vongsouvath, Manivanh; Newton, Paul N

    2013-01-01

    In most areas where typhoid is endemic, laboratory diagnosis is not possible due to the lack of appropriate facilities. We investigated whether the combination of blood culture amplification of Salmonella enterica serovar Typhi with an S. Typhi antigen rapid diagnostic test (RDT) could be an accurate and inexpensive tool for the accelerated diagnosis of patients with acute typhoid in Laos. For a panel of 23 Gram-negative reference pathogens, the Standard Diagnostics (catalog no. 15FK20; Kyonggi-do, South Korea) RDT gave positive results for S. Typhi NCTC 8385, S. Typhi NCTC 786 (Vi negative), Salmonella enterica serovar Enteritidis (ATCC 13076), and Salmonella enterica serovar Ndolo NCTC 8700 (all group D). In a prospective study of 6,456 blood culture bottles from 3,028 patients over 15 months, 392 blood culture bottles (6.1%) from 221 (7.3%) patients had Gram-negative rods (GNRs) seen in the blood culture fluid. The sensitivity, negative predictive value, specificity, and positive predictive value were 96.7%, 99.5%, 97.9%, and 87.9%, respectively, for patients with proven S. Typhi bacteremia and 91.2%, 98.4%, 98.9%, and 93.9% for patients with group D Salmonella. The median (range) number of days between diagnosis by RDT and reference assays was 1 (-1 to +2) day for those with confirmed S. Typhi. The use of antigen-based pathogen detection in blood culture fluid may be a useful, relatively rapid, inexpensive, and accurate technique for the identification of important causes of bacteremia in the tropics. PMID:23100346

  14. 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

  15. Co-Localization of Multiple Antigens and Specific DNA

    PubMed Central

    Mueller, Marcus; Wacker, Karin; Hickey, William F.; Ringelstein, Erich B.; Kiefer, Reinhard

    2000-01-01

    Co-localization of proteins and nucleic acid sequences by in situ hybridization and immunohistochemistry is frequently difficult as the process necessary to detect the target structure of one technique may negatively affect the target of the other. Morphological impairment may also limit the application of the two techniques on sensitive tissue. To overcome these problems we developed a method to perform in situ hybridization and immunohistochemistry on semithin sections of methyl methacrylate-embedded tissue. Microwave-stimulated antigen retrieval, signal amplification by catalyzed reporter deposition, and fluorescent dyes were used for both techniques, yielding high sensitivity and excellent morphological preservation compared to conventional paraffin sections. Co-localization of in situ hybridization and immunohistochemistry signals with high morphological resolution was achieved on single sections as well as on adjacent multiple serial sections, using computerized image processing. The latter allowed for the co-localization of multiple antigens and a specific DNA sequence at the same tissue level. The method was successfully applied to radiation bone marrow chimeric rats created by transplanting wild-type Lewis rat bone marrow into TK-tsa transgenic Lewis rats, in an attempt to trace and characterize TK-tsa transgenic cells. It also proved useful in the co-localization of multiple antigens in peripheral nerve biopsies. PMID:11106556

  16. 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.

  17. 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.

  18. 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

  19. 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.

  20. 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

  1. 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

  2. Improved antigenic methods for differential diagnosis of bovine, caprine, and cervine alphaherpesviruses related to bovine herpesvirus 1.

    PubMed

    Keuser, Véronique; Schynts, Frédéric; Detry, Bruno; Collard, Alfred; Robert, Béatrice; Vanderplasschen, Alain; Pastoret, Paul-Pierre; Thiry, Etienne

    2004-03-01

    The control of infectious bovine rhinotracheitis induced by bovine herpesvirus 1 (BoHV-1) requires sensitive and specific diagnostic assays. As BoHV-1 is antigenically and genetically related to four other alphaherpesviruses of ruminants-namely, BoHV-5, caprine herpesvirus 1 (CpHV-1), cervine herpesvirus 1 (CvHV-1) and CvHV-2-diagnostic tests able to discriminate BoHV-1 from these related viruses are needed to avoid misdiagnosis, especially because some of these viruses are able to cross the species barrier. In this study, murine monoclonal antibodies (MAbs) specific for BoHV-1, BoHV-5, CpHV-1, CvHV-1, and CvHV-2 were produced with the aim of setting up an immunofluorescence assay able to discriminate between these related herpesviruses. Produced MAbs were selected for their viral specificity by enzyme-linked immunosorbent assay and indirect immunofluorescence staining of virus-infected cells. Radioimmunoprecipitation characterization of the selected MAbs revealed that four of them are directed against glycoprotein C (gC) and one of them is directed against gD of these related viruses. The obtained results demonstrate that the antibodies produced allow an unambiguous discrimination of each of the four alphaherpesviruses related to BoHV-1. PMID:15004081

  3. Energy fluxes retrieval on an Alaskan Arctic and Sub-Arctic vegetation by means MODIS imagery and the DTD method

    NASA Astrophysics Data System (ADS)

    Cristobal, J.; Prakash, A.; Starkenburg, D. P.; Fochesatto, G. J.; Anderson, M. C.; Gens, R.; Kane, D. L.; Kustas, W.; Alfieri, J. G.

    2012-12-01

    Evapotranspiration (ET) plays a significant role in the hydrologic cycle of Arctic and Sub-Arctic basins. Surface-atmosphere exchanges due to ET are estimated from water balance computations to be about 74% of summer precipitation or 50% of annual precipitation. Even though ET is a significant component of the hydrologic cycle in this region, the bulk estimates don't accurately account for spatial and temporal variability due to vegetation type, topography, etc. (Kane and Yang, 2004). Nowadays, remote sensing is the only technology capable of providing the necessary radiometric measurements for the calculation of the ET at global scales and in a feasible economic way, especially in Arctic and Sub-Arctic Alaskan basins with a very sparse network of both meteorological and flux towers. In this work we present the implementation and validation of the Dual-Time-Difference model (Kustas et al., 2001) to retrieve energy fluxes (ET, sensible heat flux, net radiation and soil heat flux) in tundra vegetation in Arctic conditions and in a black spruce (Picea mariana) forest in Sub-Arctic conditions. In order to validate the model in tundra vegetation we used a flux tower from the Imnavait Creek sites of the Arctic Observatory Network (Euskirchen et al. 2012). In the case of the black spruce forest, on September 2011 we installed a flux tower in the University of Alaska Fairbanks north campus that includes an eddy-covariance system as well a net radiometer, air temperature probes, soil heat flux plates, soil moisture sensors and thermistors to fully estimate energy fluxes in the field (see http://www.et.alaska.edu/ for further details). Additionally, in order to upscale energy fluxes into MODIS spatial resolution, a scintillometer was also installed covering 1.2 km across the flux tower. DTD model mainly requires meteorological inputs as well as land surface temperature (LST) and leaf area index (LAI) data, both coming from satellite imagery, at two different times: after

  4. Hemangiosarcoma in a geriatric Labrador retriever.

    PubMed

    Sharma, Diya

    2012-08-01

    A geriatric Labrador retriever dog was presented for acute collapse. The dog was conscious but lethargic, tachypneic, tachycardic with weak femoral pulses, occasional pulse deficits, and pale mucous membranes. Radiography, ultrasonography, quick assessment tests, and a complete blood (cell) count (CBC)/biochemistry panel indicated internal hemorrhage and potential problems with hemostasis. The dog was euthanized. A necropsy, histopathology, and immunohistochemistry for CD31 and Factor VIII-related antigen cell markers supported a diagnosis of splenic hemangiosarcoma. PMID:23372199

  5. 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

  6. Image retrieval for information systems

    NASA Astrophysics Data System (ADS)

    Hermes, Thorsten; Klauck, Christoph; Kreyss, Jutta; Zhang, J.

    1995-03-01

    In order to retrieve a set of intended images from a huge image archive, human beings think of special contents with respect to the searched scene, like a countryside or a technical drawing. Therefore, in general it is harder to retrieve images by using a syntactical feature- based language than a language which offers the selection of examples concerning color, texture, and contour in combination with natural language concepts. This motivation leads to a content-based image analysis and goes on to a content-based storage and retrieval of images. Furthermore, it is unreasonable for any human being to make the content description for thousands of images manually. From this point of view, the project IRIS (image retrieval for information systems) combines well-known methods and techniques in computer vision and AI in a new way to generate content descriptions of images in a textual form automatically. IRIS retrieves the images by means of text retrieval realized by the SearchManager/6000. The textual description is generated by four sub-steps: feature extraction like colors, textures, and contours, segmentation, and interpretation of part-whole relations. The system is implemented on IBM RS/6000 using AIX. It has already been tested with 350 images.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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)

  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. Gradient Correlation Method for the Stabilization of Inversion Results of Aerosol Microphysical Properties Retrieved from Profiles of Optical Data

    NASA Astrophysics Data System (ADS)

    Kolgotin, Alexei; Müller, Detlef; Romanov, Anton; Chemyakin, Eduard

    2016-06-01

    Correlation relationships between aerosol microphysical parameters and optical data are investigated. The results show that surface-area concentrations and extinction coefficients are linearly correlated with a correlation coefficient above 0.99 for arbitrary particle size distribution. The correlation relationships that we obtained can be used as constraints in our inversion of optical lidar data. Simulation studies demonstrate a significant stabilization of aerosol microphysical data products if we apply the gradient correlation method in our traditional regularization technique.

  14. Analysis of two independent methods for retrieving liquid water profiles in spring and summer Arctic boundary clouds

    NASA Astrophysics Data System (ADS)

    LöHnert, U.; Feingold, G.; Uttal, T.; Frisch, A. S.; Shupe, M. D.

    2003-04-01

    A large number of all-liquid, nondrizzling stratus clouds (163 hours of measurements) were observed with a dual-channel microwave radiometer and a colocated 35-GHz cloud radar during the spring and summer months of the Surface Heat Budget of the Arctic Ocean (SHEBA) project. An algorithm developed by [1995, 1998] to derive the liquid water content (LWC) is applied to these measurements assuming constant cloud drop number density and cloud drop size distribution breadth with height. A second algorithm developed by [2001] is specifically adapted for SHEBA clouds using a priori information from a large eddy simulation (LES) model initialized with summertime SHEBA radiosondes; about 50 soundings during nondrizzling, low-level, all-liquid water clouds are used. Using model-derived drop size distributions, a relationship between simulated radar reflectivity (Z) and model LWC is derived as well as an a priori LWC profile. Once the theoretical error covariance matrix of the Z-LWC relation is derived and the covariance matrix of the LWC profile is calculated, an optimal estimation method is applied to the SHEBA data. The Frisch et al. and Löhnert et al. methods are also applied to the LES model output, resulting in overall root-mean-square differences on the order of 30 to 60%. Both methods are sensitive to the assumed accuracies of the microwave-radiometer-derived LWP. When applied to LES model output, the Frisch et al. method shows a LWC overestimation in the lower parts of the cloud. These systematic errors are induced by the assumption of constant cloud number concentration with height.

  15. 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.

  16. 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.

  17. 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).

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Scalable ranked retrieval using document images

    NASA Astrophysics Data System (ADS)

    Jain, Rajiv; Oard, Douglas W.; Doermann, David

    2013-12-01

    Despite the explosion of text on the Internet, hard copy documents that have been scanned as images still play a significant role for some tasks. The best method to perform ranked retrieval on a large corpus of document images, however, remains an open research question. The most common approach has been to perform text retrieval using terms generated by optical character recognition. This paper, by contrast, examines whether a scalable segmentation-free image retrieval algorithm, which matches sub-images containing text or graphical objects, can provide additional benefit in satisfying a user's information needs on a large, real world dataset. Results on 7 million scanned pages from the CDIP v1.0 test collection show that content based image retrieval finds a substantial number of documents that text retrieval misses, and that when used as a basis for relevance feedback can yield improvements in retrieval effectiveness.

  4. 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.

  5. 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

  6. Rotavirus antigen test

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003349.htm Rotavirus antigen test To use the sharing features on this page, please enable JavaScript. The rotavirus antigen test detects rotavirus in the feces. This ...

  7. Temporal structure in associative retrieval

    PubMed Central

    Kurth-Nelson, Zeb; Barnes, Gareth; Sejdinovic, Dino; Dolan, Ray; Dayan, Peter

    2015-01-01

    Electrophysiological data disclose rich dynamics in patterns of neural activity evoked by sensory objects. Retrieving objects from memory reinstates components of this activity. In humans, the temporal structure of this retrieved activity remains largely unexplored, and here we address this gap using the spatiotemporal precision of magnetoencephalography (MEG). In a sensory preconditioning paradigm, 'indirect' objects were paired with 'direct' objects to form associative links, and the latter were then paired with rewards. Using multivariate analysis methods we examined the short-time evolution of neural representations of indirect objects retrieved during reward-learning about direct objects. We found two components of the evoked representation of the indirect stimulus, 200 ms apart. The strength of retrieval of one, but not the other, representational component correlated with generalization of reward learning from direct to indirect stimuli. We suggest the temporal structure within retrieved neural representations may be key to their function. DOI: http://dx.doi.org/10.7554/eLife.04919.001 PMID:25615722

  8. 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.

  9. 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)

  10. An Introduction to Information Retrieval.

    ERIC Educational Resources Information Center

    International Business Machines Corp., White Plains, NY. Data Processing Div.

    The ways in which digital computers can be used in information storage and retrieval are presented in the language of the nonspecialist. Indexing methods, file organization, and search strategies are discussed and a brief bibliography containing 30 IBM publications is given. The manual is intended as a first reader for those interested in the…

  11. 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…

  12. 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

  13. Wellhead bowl protector and retrieving tool

    SciTech Connect

    Young, J.A.

    1991-09-03

    This patent describes improvement in a wellhead protection system including a wear bushing and a retrieving tool. The improvement comprises a wear bushing supported within the wellhead, wherein the wear bushing includes an enlarged upper end having an external support shoulder for engagement with an internal support shoulder formed in the wellhead; wherein the wear bushing further includes an internal circumferential slot intersected by at least one vertically extending slot, the vertical slot extending from the circumferential slot to the upper end of the wear bushing; a retrieving tool having at least one outwardly biased, retractable lug member mounted thereon; and wherein the retrieving tool includes an enlarged portion adapted to be received within the enlarged upper end of the wear bushing. This patent also describes a method of retrieving a wear bushing from a wellhead comprising the steps of: lowering a retrieving tool into the wellhead for locking engagement with the wear bushing; aligning the retrieving tool with the wear bushing for automatically forcing lug members carried by the retrieving tool outwardly into locking engagement with the wear bushing; monitoring drill string weight for determining engagement of the retrieving tool with the wear bushing, wherein a substantial decrease in drill string weight is an indication that the retrieving tool is engaged with the wear bushing; and removing the wear bushing from the wellhead.

  14. Adjuvant Effect of Cationic Liposomes for Subunit Influenza Vaccine: Influence of Antigen Loading Method, Cholesterol and Immune Modulators

    PubMed Central

    Barnier-Quer, Christophe; Elsharkawy, Abdelrahman; Romeijn, Stefan; Kros, Alexander; Jiskoot, Wim

    2013-01-01

    Cationic liposomes are potential adjuvants for influenza vaccines. In a previous study we reported that among a panel of cationic liposomes loaded with influenza hemagglutinin (HA), DC-Chol:DPPC (1:1 molar ratio) liposomes induced the strongest immune response. However, it is not clear whether the cholesterol (Chol) backbone or the tertiary amine head group of DC-Chol was responsible for this. Therefore, in the present work we studied the influence of Chol in the lipid bilayer of cationic liposomes. Moreover, we investigated the effect of the HA loading method (adsorption versus encapsulation) and the encapsulation of immune modulators in DC-Chol liposomes on the immunogenicity of HA. Liposomes consisting of a neutral lipid (DPPC or Chol) and a cationic compound (DC-Chol, DDA, or eDPPC) were produced by film hydration-extrusion with/without an encapsulated immune modulator (CpG or imiquimod). The liposomes generally showed comparable size distribution, zeta potential and HA loading. In vitro studies with monocyte-derived human dendritic cells and immunization studies in C57Bl/6 mice showed that: (1) liposome-adsorbed HA is more immunogenic than encapsulated HA; (2) the incorporation of Chol in the bilayer of cationic liposomes enhances their adjuvant effect; and (3) CpG loaded liposomes are more efficient at enhancing HA-specific humoral responses than plain liposomes or Alhydrogel. PMID:24300513

  15. Rapid Mycobacterial Liquid Culture-Screening Method for Mycobacterium avium Complex Based on Secreted Antigen-Capture Enzyme-Linked Immunosorbent Assay▿

    PubMed Central

    Shin, Sung Jae; Anklam, Kelly; Manning, Elizabeth J. B.; Collins, Michael T.

    2009-01-01

    Sensors in automated liquid culture systems for mycobacteria, such as MGIT, BacT/Alert 3D, and Trek ESP II, flag growth of any type of bacteria; a positive signal does not mean that the target mycobacteria are present. All signal-positive cultures thus require additional and often laborious testing. An immunoassay was developed to screen liquid mycobacterial cultures for evidence of Mycobacterium avium complex (MAC). The method, called the MAC-enzyme-linked immunosorbent assay (ELISA), relies on detection of MAC-specific secreted antigens in liquid culture. Secreted MAC antigens were captured by the MAC-ELISA with polyclonal anti- Mycobacterium avium subsp. paratuberculosis chicken immunoglobulin Y (IgY), detected using rabbit anti-MAC IgG, and then revealed using horseradish peroxidase-conjugated goat anti-rabbit IgG. When the MAC-ELISA was evaluated using pure cultures of known mycobacterial (n = 75) and nonmycobacterial (n = 17) organisms, no false-positive or false-negative MAC-ELISA results were found. By receiver operator characteristic (ROC) analysis of 1,275 previously identified clinical isolates, at the assay optimal cutoff the diagnostic sensitivity and specificity of the MAC-ELISA were 92.6% (95% confidence interval [95% CI], 90.3 to 94.5) and 99.9% (95% CI, 99.2 to 100), respectively, with an area under the ROC curve of 0.992. Prospective evaluation of the MAC-ELISA with an additional 652 clinical samples inoculated into MGIT ParaTB medium and signaling positive per the manufacturer's instructions found that the MAC-ELISA was effective in determining those cultures that actually contained MAC species and warranting the resources required to identify the organism by PCR. Of these 652 MGIT-positive cultures, the MAC-ELISA correctly identified 96.8% (of 219 MAC-ELISA-positive cultures) as truly containing MAC mycobacteria, based on PCR or high-performance liquid chromatography (HPLC) as reference tests. Only 6 of 433 MGIT signal-positive cultures (1

  16. Multilingual information retrieval system

    NASA Astrophysics Data System (ADS)

    Zhou, Hong; Chan, Syin; Lai, Kok-Fung

    1996-11-01

    In this paper, we present an approach in implementing intelligent information retrieval systems. We have constructed a multilingual information system which combines both image and text retrieval. We have developed an English/Chinese text retrieval tool on the WWW, and later incorporated an image retrieval tool based on associated multilingual captions. The system allows the general public to locate and keep abreast of information about Singapore. It has a novel user interface which accepts queries that are expressed in English, Chinese and mixed text into its database. The titles, summaries, URLs and the matching scores of retrieved documents will then be returned, and a thumbnail will be displayed as well if an image document is retrieved.

  17. 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

  18. Feasibility of asymmetrical flow field-flow fractionation as a method for detecting protective antigen by direct recognition of size-increased target-captured nanoprobes.

    PubMed

    Shin, Kayeong; Choi, Jaeyeong; Cho, Jun-Haeng; Yoon, Moon-Young; Lee, Seungho; Chung, Hoeil

    2015-11-27

    Asymmetrical flow field-flow fractionation (AF4) was evaluated as a potential analytical method for detection of a protective antigen (PA), an Anthrax biomarker. The scheme was based on the recognition of altered AF4 retention through the generation of the size-increased Au nanoparticle probes as a result of PA binding, in which a PA-selective peptide was conjugated on the probe surface. In the visible absorption-based AF4 fractograms, the band position shifted to a longer retention time as the PA concentration increased due to the presence of probe bound with PAs. The shift was insignificant when the concentration was relatively low at 84.3pM. To improve sensitivity, two separate probes conjugated with two different peptides able to bind on different PA epitopes were used together. The band shift then became distinguishable even at 84.3pM of PA sample. The formation of larger PA-probe inter-connected species using the dual-probe system was responsible for the enhanced band shift. In parallel, the feasibility of surface-enhanced Raman scattering (SERS) as a potential AF4 detection method was also evaluated. In the off-line SERS fractogram constructed using fractions collected during AF4 separation, a band shift was also observed for the 84.3pM PA sample, and the band intensity was higher when using the dual-probe system. The combination of AF4 and SERS is promising for the detection of PA and will become a potential tool if the reproducibility of SERS measurement is improved. PMID:26482872

  19. 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

  20. 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.)…

  1. 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.

  2. Information Retrieval System.

    ERIC Educational Resources Information Center

    Mahle, Jack D., Jr.

    The Fort Detrick Information Retrieval System is a system of computer programs written in COBOL for a CDC 3150 to store and retrieve information about the scientific and technical reports and documents of the Fort Detrick Technical Library. The documents and reports have been abstracted and indexed. This abstract, the subject matter descriptors,…

  3. 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.

  4. 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,…

  5. Evaluation of multi-layer cloud property retrievals from optimal estimation and Bayesian retrieval algorithms

    NASA Astrophysics Data System (ADS)

    Ding, Y.; Yang, P.

    2015-12-01

    Three physical and radiative cloud properties, namely, optical thickness (tau), effective diameter (De), and cloud top height(h) can be simultaneously inferred from IR radiances for multi-layer cloud cases. The retrieval algorithm implementation is based on a computationally efficient radiative transfer model and spaceborne measurements of narrowband infrared (IR) radiances at the top of the atmosphere. This study focuses on the evaluation of the retrieval results derived from two different algorithms, optimal estimation (OE) algorithm and Bayesian retrieval algorithm. Both of the two methods are able to offer comprehensive error analysis and quality flags. The evaluation results can potentially useful for retrieving the multi-layer clouds properties, a research subject that receives little attention. This presentation will discuss the pros and cons of retrieving cloud properties from the aforesaid retrieval algorithms.

  6. 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.

  7. Novel solid-phase refolding method for preparation of scFv-immobilized polystyrene plates with high-antigen-binding activity.

    PubMed

    Kumada, Yoichi; Shiritani, Yuki; Hamasaki, Kyoko; Nakagawa, Aya; Sasaki, Eiju; Kishimoto, Michimasa

    2010-10-01

    In the present study, we demonstrated site-specific immobilization and solid-phase refolding of single-chain Fv antibodies on hydrophilic polystyrene (phi-PS) plates that was mediated by novel polystyrene binding peptides (PS-tags: RIIIRRIRR), which were originally isolated and optimized in previous studies. Three PS-tag-fused scFvs, namely scFv-PS, scFv-(PS), and scFv-PSII, which were over-expressed in the insoluble fraction of Escherichia coli cells were denatured and site-specifically immobilized onto hydrophilic PS plates in the presence of 0.5-4 M urea and 0.1% Tween 20. The antigen-binding activity of the scFvs was efficiently recovered by washing the surface of the plate with PBS that contained 0.1% Tween 20 (PBST). The solid-phase refolding mediated by PS-tag was successfully applied to several scFvs such as mouse anti-CRP antibodies and an anti-RNase antibody, although further investigation of the versatility of scFv-PSII is needed. The maximal density of PS-tag-fused scFvs was increased more than 15-fold compared with a whole monoclonal antibody (mAb) immobilized on Maxisorp and, consequently, the sensitivity of PS-tag-fused scFvs for CRP in a sandwich ELISA was increased 25-fold. Thus, the novel, solid-phase, refolding method mediated by a PS-tag will be very useful for preparation of solid supports coated with recombinant antibody fragments, which can be used in immunoassays and immuno-separation. PMID:20661728

  8. 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)

  9. 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)

  10. An historical empirical line method for the retrieval of surface reflectance factor from multi-temporal SPOT HRV, HRVIR and HRG multispectral satellite imagery

    NASA Astrophysics Data System (ADS)

    Clark, Barnaby; Suomalainen, Juha; Pellikka, Petri

    2011-04-01

    SPOT satellites have been imaging Earth's surface since SPOT 1 was launched in 1986. It is argued that absolute atmospheric correction is a prerequisite for quantitative remote sensing. Areas where land cover changes are occurring rapidly are also often areas most lacking in situ data which would allow full use of radiative transfer models for reflectance factor retrieval (RFR). Consequently, this study details the proposed historical empirical line method (HELM) for RFR from multi-temporal SPOT imagery. HELM is designed for use in landscape level studies in circumstances where no detailed overpass concurrent atmospheric or meteorological data are available, but where there is field access to the research site(s) and a goniometer or spectrometer is available. SPOT data are complicated by the ±27° off-nadir cross track viewing. Calibration to nadir only surface reflectance factor ( ρs) is denoted as HELM-1, whilst calibration to ρs modelling imagery illumination and view geometries is termed HELM-2. Comparisons of field measured ρs with those derived from HELM corrected SPOT imagery, covering Helsinki, Finland, and Taita Hills, Kenya, indicated HELM-1 RFR absolute accuracy was ±0.02 ρs in the visible and near infrared (VIS/NIR) bands and ±0.03 ρs in the shortwave infrared (SWIR), whilst HELM-2 performance was ±0.03 ρs in the VIS/NIR and ±0.04 ρs in the SWIR. This represented band specific relative errors of 10-15%. HELM-1 and HELM-2 RFR were significantly better than at-satellite reflectance ( ρSAT), indicating HELM was effective in reducing atmospheric effects. However, neither HELM approach reduced variability in mean ρs between multi-temporal images, compared to ρSAT. HELM-1 calibration error is dependent on surface characteristics and scene illumination and view geometry. Based on multiangular ρs measurements of vegetation-free ground targets, calibration error was negligible in the forward scattering direction, even at maximum off-nadir view

  11. 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).

  12. Satellite Retrieval of Aerosol Properties

    NASA Astrophysics Data System (ADS)

    de Leeuw, G.; Robles Gonzalez, C.; Kusmierczyk-Michulec, J.; Decae, R.

    SATELLITE RETRIEVAL of AEROSOL PROPERTIES G. de Leeuw, C. Robles Gonzalez, J. Kusmierczyk-Michulec and R. Decae TNO Physics and Electronics Laboratory, The Hague, The Netherlands; deleeuw@fel.tno.nl Methods to retrieve aerosol properties over land and over sea were explored. The dual view offered by the ATSR-2 aboard ERS-2 was used by Veefkind et al., 1998. The retrieved AOD (aerosol optical depth) values compare favourably with collocated sun photometer measurements, with an accuracy of 0.06 +/- 0.05 in AOD. An algorithm developed for GOME on ERS-2 takes advantage of the low surface reflection in the UV (Veefkind et al., 2000). AOD values retrieved from ATSR-2 and GOME data over western Europe are consistent. The results were used to produce a map of mean AOD values over Europe for one month (Robles-Gonzalez et al., 2000). The ATSR-2 is al- gorithm is now extended with other aerosol types with the aim to apply it over the In- dian Ocean. A new algorithm is being developed for the Ozone Monitoring Instrument (OMI) to be launched in 2003 on the NASA EOS-AURA satellite. It is expected that, based on the different scattering and absorption properties of various aerosol types, five major aerosol classes can be distinguished. The experience with the retrieval of aerosol properties by using several wavelength bands is used to develop an algorithm for Sciamachy to retrieve aerosol properties both over land and over the ocean which takes advantage of the wavelengths from the UV to the IR. The variation of the AOD with wavelength is described by the Angstrom parameter. The AOD and the Angstrom parameter together yield information on the aerosol size distribution, integrated over the column. Analysis of sunphotometer data indicates a relation between the Angstrom parameter and the mass ratio of certain aerosols (black carbon, organic carbon and sea salt) to the total particulate matter. This relation has been further explored and was applied to satellite data over land to

  13. A novel, rapid and efficient method of cloning functional antigen-specific T-cell receptors from single human and mouse T-cells.

    PubMed

    Hamana, Hiroshi; Shitaoka, Kiyomi; Kishi, Hiroyuki; Ozawa, Tatsuhiko; Muraguchi, Atsushi

    2016-06-10

    T-cell receptor (TCR) gene therapy is a promising approach for the treatment of infectious diseases and cancers. However, the paired cloning and functional assays of antigen-specific TCRα and TCRβ is time-consuming and laborious. In this study, we developed a novel, rapid and efficient antigen-specific TCR-cloning system by combining three technologies: multiplex one-step RT-PCR, transcriptionally active PCR (TAP) and luciferase reporter assays. Multiplex one-step RT-PCR with leader primers designed from leader peptide sequences of TCRs enabled us to amplify cDNAs of TCRα and β pairs from single T-cells with remarkably high efficiency. The combination of TAP fragments and HEK293T-based NFAT-luciferase reporter cells allowed for a rapid functional assay without the need to construct expression vectors. Using this system, we cloned human TCRs specific for Epstein-Barr virus BRLF-1-derived peptide as well as mouse TCRs specific for melanoma-associated antigen tyrosinase-related protein 2 (TRP-2) within four days. These results suggest that our system provides rapid and efficient cloning of functional antigen-specific human and mouse TCRs and contributes to TCR-based immunotherapy for cancers and infectious diseases. PMID:27155153

  14. 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

  15. Quantitative evaluation of a single-distance phase-retrieval method applied on in-line phase-contrast images of a mouse lung.

    PubMed

    Mohammadi, Sara; Larsson, Emanuel; Alves, Frauke; Dal Monego, Simeone; Biffi, Stefania; Garrovo, Chiara; Lorenzon, Andrea; Tromba, Giuliana; Dullin, Christian

    2014-07-01

    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

  16. 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.

  17. Isolation and In vivo Transfer of Antigen Presenting Cells

    PubMed Central

    Arora, Pooja; Kharkwal, Shalu Sharma; Porcelli, Steven A.

    2016-01-01

    Transfer of antigen presenting cells in vivo is a method used by immunologists to examine the potency of antigen presentation by a selected population of cells. This method is most commonly used to analyze presentation of protein antigens to MHC class I or II restricted T cells, but it can also be used for studies of nonconventional antigens such as CD1-presented lipids. In a recent study focusing on CD1d-restricted glycolipid antigen presentation to Natural Killer T cells, we compared antigen presenting properties of splenic B cells, CD8αPos dendritc cells (DCs) and CD8αNeg DCs (Arora et al., 2014). This protocol describes the detailed method used for isolation of these cell populations, and their transfer into recipient mice to analyze their antigen presenting properties. PMID:27390759

  18. 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.

  19. 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

  20. RETRIEVAL EQUIPMENT DESCRIPTIONS

    SciTech Connect

    J. Steinhoff

    1997-08-25

    The objective and the scope of this document are to list and briefly describe the major mobile equipment necessary for waste package (WP) retrieval from the proposed subsurface nuclear waste repository at Yucca Mountain. Primary performance characteristics and some specialized design features of the equipment are explained and summarized in the individual subsections of this document. There are no quality assurance requirements or QA controls in this document. Retrieval under normal conditions is accomplished with the same fleet of equipment as is used for emplacement. Descriptions of equipment used for retrieval under normal conditions is found in Emplacement Equipment Descriptions, DI: BCAF00000-01717-5705-00002 (a document in progress). Equipment used for retrieval under abnormal conditions is addressed in this document and consists of the following: (1) Inclined Plane Hauler; (2) Bottom Lift Transporter; (3) Load Haul Dump (LHD) Loader; (4) Heavy Duty Forklift for Emplacement Drifts; (5) Covered Shuttle Car; (6) Multipurpose Vehicle; and (7) Scaler.

  1. 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)

  2. 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.

  3. 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

  4. Content-Based Medical Image Retrieval

    NASA Astrophysics Data System (ADS)

    Müller, Henning; Deserno, Thomas M.

    This chapter details the necessity for alternative access concepts to the currently mainly text-based methods in medical information retrieval. This need is partly due to the large amount of visual data produced, the increasing variety of medical imaging data and changing user patterns. The stored visual data contain large amounts of unused information that, if well exploited, can help diagnosis, teaching and research. The chapter briefly reviews the history of image retrieval and its general methods before technologies that have been developed in the medical domain are focussed. We also discuss evaluation of medical content-based image retrieval (CBIR) systems and conclude with pointing out their strengths, gaps, and further developments. As examples, the MedGIFT project and the Image Retrieval in Medical Applications (IRMA) framework are presented.

  5. 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.

  6. 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

  7. Neural systems behind word and concept retrieval.

    PubMed

    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 higher-order cortices of the left temporal lobe; and (B) that the retrieval of conceptual knowledge pertaining to the same concrete entities also depends on partially segregated regions; however, those regions will be different from those postulated in hypothesis A, and located predominantly in the right hemisphere (the second hypothesis tested only with the lesion method). The analyses provide support for hypothesis A in that several regions outside the classical Broca and Wernicke language areas are involved in name retrieval of concrete entities, and that there is a partial segregation in the temporal lobe with respect to the conceptual category to which the entities belong, and partial support for hypothesis B in that retrieval of conceptual knowledge is partially segregated from name retrieval in the lesion study. Those regions identified here are seen as parts of flexible, multi-component systems serving concept and word retrieval for concrete entities belonging to different conceptual categories. By comparing different approaches the article also addresses a number of method issues that have surfaced in recent studies in this field. PMID:15037130

  8. Comment on ‘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; Kottler, Christian

    2015-01-01

    In a recent paper (Scholkamm et al 2014 Phys. Med. Biol. 59 1425-40) we presented a new image denoising, fusion and enhancement framework for combining and optimal visualization of x-ray attenuation contrast, differential phase contrast and dark-field contrast images retrieved from x-ray Talbot-Lau grating interferometry. In this comment we give additional information and report about the application of our framework to breast cancer tissue which we presented in our paper as an example. The applied procedure is suitable for a qualitative comparison of different algorithms. For a quantitative juxtaposition original data would however be needed as an input.

  9. 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

  10. 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.

  11. Research on similarity measurement for texture image retrieval.

    PubMed

    Zhu, Zhengli; Zhao, Chunxia; Hou, Yingkun

    2012-01-01

    A complete texture image retrieval system includes two techniques: texture feature extraction and similarity measurement. Specifically, similarity measurement is a key problem for texture image retrieval study. In this paper, we present an effective similarity measurement formula. The MIT vision texture database, the Brodatz texture database, and the Outex texture database were used to verify the retrieval performance of the proposed similarity measurement method. Dual-tree complex wavelet transform and nonsubsampled contourlet transform were used to extract texture features. Experimental results show that the proposed similarity measurement method achieves better retrieval performance than some existing similarity measurement methods. PMID:23049785

  12. 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.

  13. The non-palindromic adaptor-PCR method for the identification of the T-cell receptor genes of an interferon-gamma-secreting T-cell hybridomaspecific for trans-sialidase, an immunodominant Trypanosoma cruzi antigen.

    PubMed

    Hiyane, M I; Boscardin, S B; Rodrigues, M M

    2006-03-01

    Cloning of the T-cell receptor genes is a critical step when generating T-cell receptor transgenic mice. Because T-cell receptor molecules are clonotypical, isolation of their genes requires reverse transcriptase-assisted PCR using primers specific for each different Valpha or Vbeta genes or by the screening of cDNA libraries generated from RNA obtained from each individual T-cell clone. Although feasible, these approaches are laborious and costly. The aim of the present study was to test the application of the non-palindromic adaptor-PCR method as an alternative to isolate the genes encoding the T-cell receptor of an antigen-specific T-cell hybridoma. For this purpose, we established hybridomas specific for trans-sialidase, an immunodominant Trypanosoma cruzi antigen. These T-cell hybridomas were characterized with regard to their ability to secrete interferon-gamma, IL-4, and IL-10 after stimulation with the antigen. A CD3+, CD4+, CD8- interferon-gamma-producing hybridoma was selected for the identification of the variable regions of the T-cell receptor by the non-palindromic adaptor-PCR method. Using this methodology, we were able to rapidly and efficiently determine the variable regions of both T-cell receptor chains. The results obtained by the non-palindromic adaptor-PCR method were confirmed by the isolation and sequencing of the complete cDNA genes and by the recognition with a specific antibody against the T-cell receptor variable beta chain. We conclude that the non-palindromic adaptor-PCR method can be a valuable tool for the identification of the T-cell receptor transcripts of T-cell hybridomas and may facilitate the generation of T-cell receptor transgenic mice. PMID:16501814

  14. Video indexing and retrieval using MPEG-7

    NASA Astrophysics Data System (ADS)

    Smith, John R.

    2002-12-01

    The ongoing growth in digital video content is increasing the need for efficient and effective systems for video indexing and retrieval. Progress is gated by developments along a number of fronts including development of tools for content annotation, invention of methods for automatic labeling and computer-assisted annotation, investigation of new techniques for indexing and retrieval, and development of standards for interoperation of video indexing and retrieval systems. MPEG-7 addresses the interoperability requirements by providing a metadata system for describing multimedia content using XML. In general, MPEG-7 allows interoperable indexing, searching, and retrieval of video, images, audio, and other forms of multimedia data. More specifically for video, MPEG-7 standardizes a number of content description tools that allow effective indexing and retrieval of video content. These tools include video segment description tools, textual annotation and transcription description tools, feature description tools, and semantics and model description tools. In this paper, we investigate the application of MPEG-7 for indexing and retrieval of video content and give examples of MPEG-7 video descriptions.

  15. 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.

  16. Proof of concept: A bioinformatic and serological screening method for identifying new peptide antigens for Chlamydia trachomatis related sequelae in women☆

    PubMed Central

    Stansfield, Scott H.; Patel, Pooja; Debattista, Joseph; Armitage, Charles W.; Cunningham, Kelly; Timms, Peter; Allan, John; Mittal, Aruna; Huston, Wilhelmina M.

    2013-01-01

    This study aimed to identify new peptide antigens from Chlamydia (C.) trachomatis in a proof of concept approach which could be used to develop an epitope-based serological diagnostic for C. trachomatis related infertility in women. A bioinformatics analysis was conducted examining several immunodominant proteins from C. trachomatis to identify predicted immunoglobulin epitopes unique to C. trachomatis. A peptide array of these epitopes was screened against participant sera. The participants (all female) were categorized into the following cohorts based on their infection and gynecological history; acute (single treated infection with C. trachomatis), multiple (more than one C. trachomatis infection, all treated), sequelae (PID or tubal infertility with a history of C. trachomatis infection), and infertile (no history of C. trachomatis infection and no detected tubal damage). The bioinformatics strategy identified several promising epitopes. Participants who reacted positively in the peptide 11 ELISA were found to have an increased likelihood of being in the sequelae cohort compared to the infertile cohort with an odds ratio of 16.3 (95% c.i. 1.65–160), with 95% specificity and 46% sensitivity (0.19–0.74). The peptide 11 ELISA has the potential to be further developed as a screening tool for use during the early IVF work up and provides proof of concept that there may be further peptide antigens which could be identified using bioinformatics and screening approaches. PMID:24600556

  17. Proof of concept: A bioinformatic and serological screening method for identifying new peptide antigens for Chlamydia trachomatis related sequelae in women.

    PubMed

    Stansfield, Scott H; Patel, Pooja; Debattista, Joseph; Armitage, Charles W; Cunningham, Kelly; Timms, Peter; Allan, John; Mittal, Aruna; Huston, Wilhelmina M

    2013-01-01

    This study aimed to identify new peptide antigens from Chlamydia (C.) trachomatis in a proof of concept approach which could be used to develop an epitope-based serological diagnostic for C. trachomatis related infertility in women. A bioinformatics analysis was conducted examining several immunodominant proteins from C. trachomatis to identify predicted immunoglobulin epitopes unique to C. trachomatis. A peptide array of these epitopes was screened against participant sera. The participants (all female) were categorized into the following cohorts based on their infection and gynecological history; acute (single treated infection with C. trachomatis), multiple (more than one C. trachomatis infection, all treated), sequelae (PID or tubal infertility with a history of C. trachomatis infection), and infertile (no history of C. trachomatis infection and no detected tubal damage). The bioinformatics strategy identified several promising epitopes. Participants who reacted positively in the peptide 11 ELISA were found to have an increased likelihood of being in the sequelae cohort compared to the infertile cohort with an odds ratio of 16.3 (95% c.i. 1.65-160), with 95% specificity and 46% sensitivity (0.19-0.74). The peptide 11 ELISA has the potential to be further developed as a screening tool for use during the early IVF work up and provides proof of concept that there may be further peptide antigens which could be identified using bioinformatics and screening approaches. PMID:24600556

  18. 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…

  19. 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…

  20. 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…

  1. 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'…

  2. OPAC Missing Record Retrieval.

    ERIC Educational Resources Information Center

    Johnson, Karl E.

    1996-01-01

    When the Higher Education Library Information Network of Rhode Island transferred members' bibliographic data into a shared online public access catalog (OPAC), 10% of the University of Rhode Island's monograph records were missing. This article describes the consortium's attempts to retrieve records from the database and the effectiveness of…

  3. Information Retrieval Systems.

    ERIC Educational Resources Information Center

    National Archives and Records Service (GSA), Washington, DC. Office of Records Management.

    Descriptions of representative nonconventional information systems in use today are given in order to provide managers, management analysts, supervisors, and others with ideas as to how they might improve the dissemination, storage, and retrieval of information in their offices. No attempt was made to evaluate the relative merits of the systems…

  4. 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.…

  5. 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…

  6. 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

  7. 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…

  8. 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.

  9. 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%.

  10. 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

  11. Alcohol and Memory: Retrieval Processes

    ERIC Educational Resources Information Center

    Birnbaum, Isabel M.; And Others

    1978-01-01

    The influence of alcohol intoxication on the retrieval of information from memory was investigated in nonalcoholic subjects Intoxicated subjects recalled fewer categories and words within categories. The retrieval stage of memory did not appear to be affected by alcohol. (SW)

  12. A new therapeutic antibody removal method using antigen-positive red cells. II. Application to a P-incompatible pregnant woman.

    PubMed

    Yoshida, H; Ito, K; Emi, N; Kanzaki, H; Matsuura, S

    1984-01-01

    Therapeutic antibody removal using antigen-positive red cells was applied to a pregnant woman who has high titered IgG anti-P and had lost all of 4 previous fetuses in P-incompatible pregnancy. The treatment was commenced at the 6th week of gestation and was intensively performed 93 times up to the 35th week. The volume of plasma treated was 2.3 1 per procedure on the average and totalled 215 1. The antibody titer was kept at a low level. At the end of the 35th week of gestation a female infant was delivered by cesarean section. The baby did not require an exchange transfusion and encountered no complications. PMID:6464420

  13. Lipid antigens in immunity

    PubMed Central

    Dowds, C. Marie; Kornell, Sabin-Christin

    2014-01-01

    Lipids are not only a central part of human metabolism but also play diverse and critical roles in the immune system. As such, they can act as ligands of lipid-activated nuclear receptors, control inflammatory signaling through bioactive lipids such as prostaglandins, leukotrienes, lipoxins, resolvins, and protectins, and modulate immunity as intracellular phospholipid- or sphingolipid-derived signaling mediators. In addition, lipids can serve as antigens and regulate immunity through the activation of lipid-reactive T cells, which is the topic of this review. We will provide an overview of the mechanisms of lipid antigen presentation, the biology of lipid-reactive T cells, and their contribution to immunity. PMID:23999493

  14. Mobile medical image retrieval

    NASA Astrophysics Data System (ADS)

    Duc, Samuel; Depeursinge, Adrien; Eggel, Ivan; Müller, Henning

    2011-03-01

    Images are an integral part of medical practice for diagnosis, treatment planning and teaching. Image retrieval has gained in importance mainly as a research domain over the past 20 years. Both textual and visual retrieval of images are essential. In the process of mobile devices becoming reliable and having a functionality equaling that of formerly desktop clients, mobile computing has gained ground and many applications have been explored. This creates a new field of mobile information search & access and in this context images can play an important role as they often allow understanding complex scenarios much quicker and easier than free text. Mobile information retrieval in general has skyrocketed over the past year with many new applications and tools being developed and all sorts of interfaces being adapted to mobile clients. This article describes constraints of an information retrieval system including visual and textual information retrieval from the medical literature of BioMedCentral and of the RSNA journals Radiology and Radiographics. Solutions for mobile data access with an example on an iPhone in a web-based environment are presented as iPhones are frequently used and the operating system is bound to become the most frequent smartphone operating system in 2011. A web-based scenario was chosen to allow for a use by other smart phone platforms such as Android as well. Constraints of small screens and navigation with touch screens are taken into account in the development of the application. A hybrid choice had to be taken to allow for taking pictures with the cell phone camera and upload them for visual similarity search as most producers of smart phones block this functionality to web applications. Mobile information access and in particular access to images can be surprisingly efficient and effective on smaller screens. Images can be read on screen much faster and relevance of documents can be identified quickly through the use of images contained in

  15. Satellite services and orbital retrieval

    NASA Technical Reports Server (NTRS)

    Adornato, R. J.

    1985-01-01

    Within the capabilities of the Space Shuttle Orbiter, a broad range of services which can be made available to the satellite user community as summarized. Payload deployment, close proximity retrieval, and a number of other mission related functions are discussed. The focus here is on close proximity retrieval and retrieval of payloads in higher energy low Earth orbits.

  16. 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…

  17. 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…

  18. 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

  19. 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.

  20. Satellite retrieval system

    NASA Technical Reports Server (NTRS)

    Pruett, E. C.; Robertson, K. B.; Loughead, T. E. (Inventor)

    1983-01-01

    A satellite retrieval system with first and second pairs of coacting parallel bars are separately mounted in spaced parallel planes on the front of a spacecraft. The bars of one pair are at right angles to bars of the other pair, and together the two pairs of bars effect a variable aperture adapted to close around a rod extending from a second spacecraft to effect the capture of the latter.

  1. 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.

  2. 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 tissue 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 methodology is chosen ...

  3. Antigen smuggling in tuberculosis.

    PubMed

    Hudrisier, Denis; Neyrolles, Olivier

    2014-06-11

    The importance of CD4 T lymphocytes in immunity to M. tuberculosis is well established; however, how dendritic cells activate T cells in vivo remains obscure. In this issue of Cell Host & Microbe, Srivastava and Ernst (2014) report a mechanism of antigen transfer for efficient activation of antimycobacterial T cells. PMID:24922567

  4. 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...

  5. Multisensor Retrieval of Atmospheric Properties.

    NASA Astrophysics Data System (ADS)

    Boba Stankov, B.

    1998-09-01

    A new method, Multisensor Retrieval of Atmospheric Properties (MRAP), is presented for deriving vertical profiles of atmospheric parameters throughout the troposphere. MRAP integrates measurements from multiple, diverse, remote sensing, and in situ instruments, the combination of which provides better capabilities than any instrument alone. Since remote sensors can deliver measurements automatically and continuously with high time resolution, MRAP provides better coverage than traditional rawinsondes. MRAP's design is flexible, being capable of incorporating measurements from different instruments in order to take advantage of new or developing advanced sensor technology. Furthermore, new or alternative atmospheric parameters for a variety of applications may be easily added as products of MRAP.A combination of passive radiometric, active radar, and in situ observations provide the best temperature and humidity profile measurements. Therefore, MRAP starts with a traditional, radiometer-based, physical retrieval algorithm provided by the International TOVS (TIROS-N Operational Vertical Sounder) Processing Package (ITPP) that constrains the retrieved profiles to agree with brightness temperature measurements. The first-guess profiles required by the ITPP's iterative retrieval algorithm are obtained by using a statistical inversion technique and ground-based remote sensing measurements. Because the individual ground-based remote sensing measurements are usually of sufficiently high quality, the first-guess profiles by themselves provide a satisfactory solution to establish the atmospheric water vapor and temperature state, and the TOVS data are included to provide profiles with better accuracy at higher levels, MRAP provides a physically consistent mechanism for combining the ground- and space-based humidity and temperature profiles.Data that have been used successfully to retrieve humidity and temperature profiles with MRAP are the following: temperature profiles in

  6. Aspergillus antigen skin test (image)

    MedlinePlus

    The aspergillus antigen skin test determines whether or not a person has been exposed to the mold aspergillus. It is performed by injecting an aspergillus antigen under the skin with a needle. After 48 ...

  7. Monetary rewards influence retrieval orientations.

    PubMed

    Halsband, Teresa M; Ferdinand, Nicola K; Bridger, Emma K; Mecklinger, Axel

    2012-09-01

    Reward anticipation during learning is known to support memory formation, but its role in retrieval processes is so far unclear. Retrieval orientations, as a reflection of controlled retrieval processing, are one aspect of retrieval that might be modulated by reward. These processes can be measured using the event-related potentials (ERPs) elicited by retrieval cues from tasks with different retrieval requirements, such as via changes in the class of targeted memory information. To determine whether retrieval orientations of this kind are modulated by reward during learning, we investigated the effects of high and low reward expectancy on the ERP correlates of retrieval orientation in two separate experiments. The reward manipulation at study in Experiment 1 was associated with later memory performance, whereas in Experiment 2, reward was directly linked to accuracy in the study task. In both studies, the participants encoded mixed lists of pictures and words preceded by high- or low-reward cues. After 24 h, they performed a recognition memory exclusion task, with words as the test items. In addition to a previously reported material-specific effect of retrieval orientation, a frontally distributed, reward-associated retrieval orientation effect was found in both experiments. These findings suggest that reward motivation during learning leads to the adoption of a reward-associated retrieval orientation to support the retrieval of highly motivational information. Thus, ERP retrieval orientation effects not only reflect retrieval processes related to the sought-for materials, but also relate to the reward conditions with which items were combined during encoding. PMID:22547161

  8. Biomedical information retrieval across languages.

    PubMed

    Daumke, Philipp; Markü, Kornél; Poprat, Michael; Schulz, Stefan; Klar, Rüdiger

    2007-06-01

    This work presents a new dictionary-based approach to biomedical cross-language information retrieval (CLIR) that addresses many of the general and domain-specific challenges in current CLIR research. Our method is based on a multilingual lexicon that was generated partly manually and partly automatically, and currently covers six European languages. It contains morphologically meaningful word fragments, termed subwords. Using subwords instead of entire words significantly reduces the number of lexical entries necessary to sufficiently cover a specific language and domain. Mediation between queries and documents is based on these subwords as well as on lists of word-n-grams that are generated from large monolingual corpora and constitute possible translation units. The translations are then sent to a standard Internet search engine. This process makes our approach an effective tool for searching the biomedical content of the World Wide Web in different languages. We evaluate this approach using the OHSUMED corpus, a large medical document collection, within a cross-language retrieval setting. PMID:17541863

  9. 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.

  10. Problems and Approaches to Cross Language Information Retrieval.

    ERIC Educational Resources Information Center

    Grefenstette, Gregory

    1998-01-01

    Discusses the problems and current research techniques being explored in the area of Cross Language Information Retrieval (CLIR) for finding documents in languages other than the original query. Discusses language identification methods, techniques for automatically generating queries in other languages, and retrieving and merging query results.…

  11. 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.…

  12. 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)

  13. PAPERS: A Simple Object-Oriented Text Retrieval System.

    ERIC Educational Resources Information Center

    Wade, Stephen

    1993-01-01

    Describes how an interactive text retrieval system with natural language queries is used in information studies education. The benefits of programing methods involving encapsulation and inheritance are explained in terms of reusability and extendibility, and future plans to produce a library of reusable objects for information retrieval are…

  14. 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;…

  15. 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…

  16. 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…

  17. 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…

  18. Is Retrieval Mediated after Repeated Testing?

    ERIC Educational Resources Information Center

    Kole, James A.; Healy, Alice F.

    2013-01-01

    In 2 main experiments, the mediated priming effect was used to determine whether retrieval continues to be mediated after repeated testing. In each experiment, participants used the keyword method to learn French vocabulary, then completed a modified lexical decision task in which they first translated a French word, and then made a lexical…

  19. A Developmental Study of Intelligent Retrieval.

    ERIC Educational Resources Information Center

    Keniston, Allen H.; Flavell, John H.

    1979-01-01

    Among elementary, junior high, and college students, intelligent retrieval methods for recalling 20 letters of the alphabet consisted either of mentally proceeding through the alphabet from the onset and writing down each previously written letter as encountered and recognized, or else first rote recalling some letters and then switching to the…

  20. Quantum image with high retrieval performance

    NASA Astrophysics Data System (ADS)

    Ruan, Yue; Chen, Hanwu; Liu, Zhihao; Tan, Jianing

    2016-02-01

    Quantum image retrieval is an exhaustive work due to exponential measurements. Casting aside the background of image processing, quantum image is a pure many-body state, and the retrieval task is a physical process named as quantum state tomography. Tomography of a special class of states, permutationally symmetric states, just needs quadratic measurement scales with the number of qubits. In order to take advantage of this result, we propose a method to map the main energy of the image to these states. First, we deduce that n+1 permutationally symmetric states can be constructed as bases of 2^n Hilbert space ( n qubits) at least. Second, we execute Schmidt decomposition by continually bipartite splitting of the quantum image (state). At last, we select n+1 maximum coefficients, do base transformation to map these coefficients to new bases (permutationally symmetric states). By these means, the quantum image with high retrieval performance can be gotten.

  1. 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.

  2. 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

  3. Antigens provide immunity against Ich in channel catfish trials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies were conducted to determine effects of 1) types of Ich antigens and routes of immunization, 2) methods of inactivated trophonts, and 3) antigen doses on fish immune protection against Ichthyophthirius multifiliis Fouquet (Ich). All catfish immunized with live theronts by immersion, live the...

  4. 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.

  5. Autonomous Phase Retrieval Calibration

    NASA Technical Reports Server (NTRS)

    Estlin, Tara A.; Chien, Steve A.; Castano, Rebecca; Gaines, Daniel M.; Doubleday, Joshua R.; Schoolcraft, Josua B.; Oyake, Amalaye; Vaughs, Ashton G.; Torgerson, Jordan L.

    2011-01-01

    The Palomar Adaptive Optics System actively corrects for changing aberrations in light due to atmospheric turbulence. However, the underlying internal static error is unknown and uncorrected by this process. The dedicated wavefront sensor device necessarily lies along a different path than the science camera, and, therefore, doesn't measure the true errors along the path leading to the final detected imagery. This is a standard problem in adaptive optics (AO) called "non-common path error." The Autonomous Phase Retrieval Calibration (APRC) software suite performs automated sensing and correction iterations to calibrate the Palomar AO system to levels that were previously unreachable.

  6. 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

  7. Cancer testis antigen and immunotherapy

    PubMed Central

    Krishnadas, Deepa Kolaseri; Bai, Fanqi; Lucas, Kenneth G

    2013-01-01

    The identification of cancer testis (CT) antigens has been an important advance in determining potential targets for cancer immunotherapy. Multiple previous studies have shown that CT antigen vaccines, using both peptides and dendritic cell vaccines, can elicit clinical and immunologic responses in several different tumors. This review details the expression of melanoma antigen family A, 1 (MAGE-A1), melanoma antigen family A, 3 (MAGE-A3), and New York esophageal squamous cell carcinoma-1 (NY-ESO-1) in various malignancies, and presents our current understanding of CT antigen based immunotherapy.

  8. 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.

  9. Automatic Evidence Retrieval for Systematic Reviews

    PubMed Central

    Choong, Miew Keen; Galgani, Filippo; Dunn, Adam G

    2014-01-01

    Background Snowballing involves recursively pursuing relevant references cited in the retrieved literature and adding them to the search results. Snowballing is an alternative approach to discover additional evidence that was not retrieved through conventional search. Snowballing’s effectiveness makes it best practice in systematic reviews despite being time-consuming and tedious. Objective Our goal was to evaluate an automatic method for citation snowballing’s capacity to identify and retrieve the full text and/or abstracts of cited articles. Methods Using 20 review articles that contained 949 citations to journal or conference articles, we manually searched Microsoft Academic Search (MAS) and identified 78.0% (740/949) of the cited articles that were present in the database. We compared the performance of the automatic citation snowballing method against the results of this manual search, measuring precision, recall, and F1 score. Results The automatic method was able to correctly identify 633 (as proportion of included citations: recall=66.7%, F1 score=79.3%; as proportion of citations in MAS: recall=85.5%, F1 score=91.2%) of citations with high precision (97.7%), and retrieved the full text or abstract for 490 (recall=82.9%, precision=92.1%, F1 score=87.3%) of the 633 correctly retrieved citations. Conclusions The proposed method for automatic citation snowballing is accurate and is capable of obtaining the full texts or abstracts for a substantial proportion of the scholarly citations in review articles. By automating the process of citation snowballing, it may be possible to reduce the time and effort of common evidence surveillance tasks such as keeping trial registries up to date and conducting systematic reviews. PMID:25274020

  10. Retrievable Inferior Vena Cava Filters in Patients with Cancer: Complications and Retrieval Success Rate

    PubMed Central

    Casanegra, Ana I.; Landrum, Lisa M.; Tafur, Alfonso J.

    2016-01-01

    Active cancer (ACa) is strongly associated with venous thromboembolism and bleeding. Retrievable inferior vena cava filters (RIVCF) are frequently placed in these patients when anticoagulation cannot be continued. Objectives. To describe the complications and retrieval rate of inferior vena cava filters in patients with ACa. Methods. Retrospective review of 251 consecutive patients with RIVCF in a single institution. Results. We included 251 patients with RIVCF with a mean age of 58.1 years and a median follow-up of 5.4 months (164 days, IQR: 34–385). Of these patients 32% had ACa. There were no differences in recurrence rate of DVT between patients with ACa and those without ACa (13% versus 17%, p = ns). Also, there were no differences in major filter complications (11% ACa versus 7% no ACa, p = ns). The filter retrieval was not different between groups (log-rank = 0.16). Retrieval rate at 6 months was 49% in ACa patients versus 64% in patients without ACa (p = ns). Filter retrieval was less frequent in ACa patients with metastatic disease (p < 0.01) or a nonsurgical indication for filter placement (p = 0.04). Conclusions. No differences were noted in retrieval rate, recurrent DVT, or filter complications between the two groups. ACa should not preclude the use of RIVCF. PMID:26904290

  11. 3D object retrieval using salient views.

    PubMed

    Atmosukarto, Indriyati; Shapiro, Linda G

    2013-06-01

    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

  12. 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

  13. 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.

  14. Mapping epitopes and antigenicity by site-directed masking

    PubMed Central

    Paus, Didrik; Winter, Greg

    2006-01-01

    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 (β-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 β-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 β-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. PMID:16754878

  15. Enhanced Information Retrieval Using AJAX

    NASA Astrophysics Data System (ADS)

    Kachhwaha, Rajendra; Rajvanshi, Nitin

    2010-11-01

    Information Retrieval deals with the representation, storage, organization of, and access to information items. The representation and organization of information items should provide the user with easy access to the information with the rapid development of Internet, large amounts of digitally stored information is readily available on the World Wide Web. This information is so huge that it becomes increasingly difficult and time consuming for the users to find the information relevant to their needs. The explosive growth of information on the Internet has greatly increased the need for information retrieval systems. However, most of the search engines are using conventional information retrieval systems. An information system needs to implement sophisticated pattern matching tools to determine contents at a faster rate. AJAX has recently emerged as the new tool such the of information retrieval process of information retrieval can become fast and information reaches the use at a faster pace as compared to conventional retrieval systems.

  16. Ranking Refinement via Relevance Feedback in Geographic Information Retrieval

    NASA Astrophysics Data System (ADS)

    Villatoro-Tello, Esaú; Villaseñor-Pineda, Luis; Montes-Y-Gómez, Manuel

    Recent evaluation results from Geographic Information Retrieval (GIR) indicate that current information retrieval methods are effective to retrieve relevant documents for geographic queries, but they have severe difficulties to generate a pertinent ranking of them. Motivated by these results in this paper we present a novel re-ranking method, which employs information obtained through a relevance feedback process to perform a ranking refinement. Performed experiments show that the proposed method allows to improve the generated ranking from a traditional IR machine, as well as results from traditional re-ranking strategies such as query expansion via relevance feedback.

  17. 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.

  18. 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.

  19. 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.

  20. Nonsurgical retrieval of embolized coronary stents.

    PubMed

    Eggebrecht, H; Haude, M; von Birgelen, C; Oldenburg, O; Baumgart, D; Herrmann, J; Welge, D; Bartel, T; Dagres, N; Erbel, R

    2000-12-01

    Embolization of coronary stents before deployment is a rare but challenging complication of coronary stenting. Different methods for nonsurgical stent retrieval have been suggested. There were 20 cases (0.90%) of intracoronary stent embolization among 2,211 patients who underwent implantation of 4,066 stents. Twelve of 1,147 manually crimped stents (1.04%) and eight of 2,919 premounted stents were lost (0.27%, P < 0.01) during retraction of the delivery system, because the target lesion could not be either reached or crossed. Percutaneous retrieval was successfully carried out in 10 of 14 patients (71%) in whom retrieval was attempted. In 10 patients, stent retrieval was tried with 1.5-mm low-profile angioplasty balloon catheters (success in 7/10) and in seven cases with myocardial biopsy forceps or a gooseneck snare (success in 3/7). Three patients (15%) underwent urgent coronary artery bypass surgery after failed percutaneous retrieval, but their outcomes were fatal. In two patients, stents were compressed against the vessel wall by another stent, without compromising coronary blood flow. In two patients, a stent was lost to the periphery without clinical side effects; treatment was conservative in these cases. Embolization of stents before deployment is a rare but serious complication of coronary stenting, with hazardous potential for the patient. Manual mounting of stents is associated with a significantly higher risk of stent embolization. Stent retrieval from the coronary circulation with low-profile angioplasty balloon catheters is a readily available and technically familiar approach that has a relatively high success rate. PMID:11108675

  1. 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

  2. Isolation and antigenicity of a 45-kilodalton Paracoccidioides brasiliensis immunodominant antigen.

    PubMed Central

    Ferreira-da-Cruz, M F; Galvão-Castro, B; Daniel-Ribeiro, C

    1992-01-01

    In the present study, we analyzed human antibody responses to Paracoccidioides brasiliensis cellular antigens by the immunoblot technique to identify specific cellular components and to investigate the existence of antigen profile differences among serological responses of paracoccidioidomycosis (PCM) patients. Among the 64 PCM serum samples analyzed, a relatively homogeneous immunoglobulin G response to P. brasiliensis antigens was observed. The polypeptide with a mass of 45 kDa was the most clinically important, since antibody to this antigen was detectable in 90.6% of PCM patients studied and the six individuals who did not produce antibody were either at the end of treatment or in the posttherapy period and had shown clinical recovery. These facts suggested that the presence of this antibody may be an indicator of active disease. The 45-kDa antigen was also the most specific antigen of the PCM humoral immune response, since it reacted with only 2 of 79 (2.5%) heterologous serum samples tested: 1 histoplasmosis case and 1 tuberculosis case. This polypeptide was isolated from gels by electroelution and, when tested by an immunoradiometric assay and immunoblotting, maintained its reactivity with PCM sera and also with anti-P. brasiliensis polyclonal antibodies raised in rabbits at the same sensitivity levels as those obtained in immunoblotting with a crude antigen. Since in our assays the 45-kDa polypeptide was the major P. brasiliensis antigen and seemed to be specific for PCM, its use in alternative diagnostic methods is promising, especially in patients suspected of having the juvenile clinical form of PCM often associated with negative double-immunodiffusion results. Images PMID:1612736

  3. [Identification of serological antigens in excretory-secretory antigens of Trichinella spiralis muscle larvae].

    PubMed

    Huang, Xuegui; He, Lifang; Yuan, Shishan; Liu, Hui; Wang, Xin

    2016-05-01

    Objective To isolate and identify serological antigens in the excretory-secretory antigens of Trichinella spiralis muscle larvae by the combination of co-immunoprecipitation and mass spectrometric technology. Methods The serum IgG of New Zealand rabbits infected with Trichinella spiralis was isolated by ammonium sulfate precipitation. Muscle larvaes were isolated from the infected muscle, and then purified and cultured to collect excretory-secretory antigens. Serological antigens in excretory-secretory antigens were isolated by co-immunoprecipitation and SDS-PAGE, and analyzed by Western blotting. Moreover, the protein bands in New Zealand rabbit sera infected with Trichinella spiralis were identified by mass spectrometric technology. Results Indirect ELISA showed that the titer of serum antibody of New Zealand rabbits infected with Trichinella spiralis was 1:6400. The rabbit serum IgG was effectively isolated by ammonium sulfate precipitation. A total of four clear protein bands of the excretory-secretory antigens of Trichinella spiralis were obtained by electrophoresis. Among them, three clear protein bands with relative molecular mass (Mr) being 40 kDa, 50 kDa and 83 kDa were recognized by the rabbit sera infected with Trichinella spiralis but not recognized by the normal rabbit sera. The obtained four protein molecules were confirmed as serine protease, specific serine protease of muscle larvae, 43 kDa secreted glycoprotein and 53 kDa excretory-secretory antigen. Conclusion Four proteins were obtained from the excretory-secretory antigens of Trichinella spiralis muscle larvae by combination of co-immunoprecipitation and mass spectrometric technique analysis, which provided new sources and insights for the diagnosis and vaccine candidates of Trichinellosis. PMID:27126943

  4. Robust retrieval from compressed medical image archives

    NASA Astrophysics Data System (ADS)

    Sidorov, Denis N.; Lerallut, Jean F.; Cocquerez, Jean-Pierre; Azpiroz, Joaquin

    2005-04-01

    Paper addresses the computational aspects of extracting important features directly from compressed images for the purpose of aiding biomedical image retrieval based on content. The proposed method for treatment of compressed medical archives follows the JPEG compression standard and exploits algorithm based on spacial analysis of the image cosine spectrum coefficients amplitude and location. The experiments on modality-specific archive of osteoarticular images show robustness of the method based on measured spectral spatial statistics. The features, which were based on the cosine spectrum coefficients' values, could satisfy different types of queries' modalities (MRI, US, etc), which emphasized texture and edge properties. In particular, it has been shown that there is wealth of information in the AC coefficients of the DCT transform, which can be utilized to support fast content-based image retrieval. The computational cost of proposed signature generation algorithm is low. Influence of conventional and the state-of-the-art compression techniques based on cosine and wavelet integral transforms on the performance of content-based medical image retrieval has been also studied. We found no significant differences in retrieval efficiencies for non-compressed and JPEG2000-compressed images even at the lowest bit rate tested.

  5. 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.

  6. Retrieval of Aerosol Height with TROPOMI

    NASA Astrophysics Data System (ADS)

    Sanders, A. F. J.; de Haan, J. F.; Veefkind, J. P.

    2012-04-01

    The Tropospheric Monitoring Instrument (TROPOMI), to be launched in 2015, will feature a new aerosol product providing the height of aerosol layers. Aerosol Layer Height will be one of two aerosol products, the other one being the Absorbing Aerosol Index. TROPOMI is a UV-VIS-NIR imaging spectrometer with daily global coverage. It will be part of ESA's Sentinel-5 Precursor mission. Algorithm development for the aerosol height product is currently underway at KNMI. In this presentation we will introduce the algorithm, highlight some of the development issues and discuss possible applications and example aerosol cases. Aerosol height observations from the near-infrared wavelength range will improve retrieval of other aerosol properties, particularly retrieval of absorption optical thickness. An increase in absorption in the ultraviolet wavelength range can be due to a higher imaginary part of the refractive index or to the aerosol layer being at a higher altitude. Independent height observations will therefore further constrain retrieval of the single scattering albedo. Furthermore, aerosol profile information is an important parameter when estimating radiative forcings and climate impacts of aerosol, it is a significant source of uncertainty in trace gas retrieval and it helps in understanding atmospheric transport mechanisms. Finally, timely available, global observations of aerosol height will be of interest to aviation safety agencies. The retrieval algorithm for aerosol height will be based on absorption by oxygen in the A-band (759-770 nm). Aerosols are assumed to be contained in a single layer. A spectral fit of reflectance (resolution 0.5 nm) across the absorption band provides layer height. The retrieval method will be optimal estimation to ensure a proper error analysis. Sensitivity studies have indicated that accuracy and precision of retrieved height for cloud-free scenes will be well below the TROPOMI science requirements (1 km). They have also shown that

  7. 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.

  8. 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.

  9. 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...

  10. Snippet Generation for Geographic Information Retrieval

    NASA Astrophysics Data System (ADS)

    Toda, Hiroyuki; Yasuda, Norihito; Okumura, Manabu; Matsuura, Yumiko; Kataoka, Ryoji

    Geographic information retrieval (GIR) aims at the retrieval of geographic-related documents based through the use of not only on keyword relevance but also on geographic relationships between the query and the geographic information in the texts. However, how to show search results in GIR has not been studied well, especially with regard to generating snippets that reflect the geographic part of the query. This paper proposes a novel snippet generation method. Our method first converts geographic phrases in the target text into geographic coordinates, then scores each of them according to their distance from the query using the coordinates. Next, it extracts fragments of the target text based on the distribution of the query keyword and geographic scores, and presents the combined fragments as a snippet. Evaluations are conducted with regard to two different aspects. Both attributes confirm the effectiveness of our method.

  11. An evaluation of unmediated versus mediated retrieval services.

    PubMed Central

    Buntrock, James D.; Chute, Christopher G.

    2002-01-01

    To understand if unmediated services could serve the data retrieval needs for the Mayo research investigator, a study was conducted to determine researcher interest, ability, and outcome of using a clinical data retrieval system. The results indicate about 25% of the research investigators would use a self-service retrieval tool. However, there is clear evidence a majority of the research investigators are satisfied with and prefer the mediated service because of convenience, retrieval specialist knowledge, and lack of time to perform the search themselves. Approximately 61% of the non-participants indicated they would be willing to pay a fee for continued use of the mediated service. This study confirms the interest in self-service retrieval tools, but the actual interest is lower than anticipated. The recommendation is to continue the use of mediated services and to offer self-service methods as needed, allowing the most options to the research investigator. PMID:12463791

  12. Combining approaches to on-line handwriting information retrieval

    NASA Astrophysics Data System (ADS)

    Peña Saldarriaga, Sebastián; Viard-Gaudin, Christian; Morin, Emmanuel

    2010-01-01

    In this work, we propose to combine two quite different approaches for retrieving handwritten documents. Our hypothesis is that different retrieval algorithms should retrieve different sets of documents for the same query. Therefore, significant improvements in retrieval performances can be expected. The first approach is based on information retrieval techniques carried out on the noisy texts obtained through handwriting recognition, while the second approach is recognition-free using a word spotting algorithm. Results shows that for texts having a word error rate (WER) lower than 23%, the performances obtained with the combined system are close to the performances obtained on clean digital texts. In addition, for poorly recognized texts (WER > 52%), an improvement of nearly 17% can be observed with respect to the best available baseline method.

  13. Information Retrieval Systems and Learning.

    ERIC Educational Resources Information Center

    Locatis, Craig

    1989-01-01

    Discusses instructional systems and information retrieval systems and highlights the growing role of retrieval systems in learning. Topics discussed include cognitive psychology; degree of learner control; interaction with the systems; technological trends, including storage capacity, integrated media, and interlinked systems; hypermedia; and…

  14. A Computerized Reference Retrieval System.

    ERIC Educational Resources Information Center

    Harline, N. La Var

    An automated retrieval system for reference works was constructed as a prototype in order to illustrate the capabilities and potentialities of future retrieval systems. More than 170 biographical works were indexed and stored in a computer disk to form a biographical data base, and a computer program was written to match patron queries. Consistent…

  15. 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)

  16. NASA develops teleoperator retrieval system

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The teleoperator retrieval system vehicle was designed to reboost and/or deorbit the Skylab; however, usefulness in survey, stabilization, retrieval and delivery was examined. Thrusters, designed for cold gas propulsion, were adapted to hydrazine propulsion. Design specifications and cost analysis are given.

  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. 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…

  19. Retrieval Effectiveness on the Web.

    ERIC Educational Resources Information Center

    Savoy, Jacques; Picard, Justin

    2001-01-01

    Discusses the role of search engines in Web usability and analyzes and evaluates the retrieval effectiveness of various indexing and searching strategies on a new Web text collection. Highlights include preprocessing techniques that might improve retrieval effectiveness; and hyperlinks as useful sources of evidence in improving retrieval…

  20. 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.

  1. 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. PMID:20521635

  2. Human leucocyte antigens in tympanosclerosis.

    PubMed

    Dursun, G; Acar, A; Turgay, M; Calgüner, M

    1997-02-01

    This study was designed to evaluate the association between certain HLA antigens and tympanosclerosis. The serum concentrations of HLA antigens were measured by a microlymphocytotoxicity technique in patients with tympanosclerosis and compared with a healthy control group. The serum levels of HLA-B35 and -DR3 were significantly higher in the patients with tympanosclerosis. This result suggests that certain types of HLA antigens may play an important role as an indicator or mediator in the pathogenesis of tympanosclerosis. PMID:9088683

  3. Foundations of Advanced Information Visualization for Visual Information (Retrieval) Systems.

    ERIC Educational Resources Information Center

    Rorvig, Mark; Hemmje, Matthias

    1999-01-01

    Reports on a conference workshop that addressed Visual Information Retrieval Interfaces (VIRIs). Topics include evaluation methods; task dimension for evaluating VIRIs; efforts to fund European development of VIRIs; metrics, including cosine vector; navigation among documents; and interactions with users. (LRW)

  4. Test plan for the retrieval demonstration

    SciTech Connect

    Valentich, D.J.

    1993-05-01

    This test plan describes a simulated buried waste retrieval demonstration that will be performed at the Caterpillar, Inc., Edwards Training Center located near Peoria, Illinois. The purpose of the demonstration is to determine the effectiveness of using readily available excavation equipment to retrieve, size, and handle various simulated waste forms that are similar in size, structure, and composition to those expected to be found in US Department of Energy contaminated waste pits and trenches. The objectives of this demonstration are to: meet and maintain daily production goals of 80 yd{sup 3}/day; minimize spillage and dust generation through careful and deliberate operations; document and evaluate methods for manipulating, sizing, and/or working around large objects; and document and evaluate requirements for operator augmentation and remote operation for hot test pit excavation operations. Four conditions comprising the range of environments to be evaluated include excavation of random material from below grade; stacked boxes and barrels from below grade; random materials from at grade; and stacked boxes and barrels from at grade. Results of the retrieval demonstration will reduce unknowns in the body of knowledge about retrieval equipment and procedural options for removal of buried transuranic (TRU) waste at the Idaho National Engineering Laboratory. It is anticipated that DOE will factor this information into a remedial investigation/feasibility plan leading to a final record of decision for disposition of buried TRU waste.

  5. 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.

  6. 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.

  7. Novel antigen delivery systems.

    PubMed

    Trovato, Maria; De Berardinis, Piergiuseppe

    2015-08-12

    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

  8. 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

  9. Quantum dot based fluorometric detection of cancer TF-antigen.

    PubMed

    Li, Nan; Chow, Ari M; Ganesh, Hashwin V S; Brown, Ian R; Kerman, Kagan

    2013-10-15

    Cancer is a major global health challenge that would benefit from advances in screening methods for early detection that are rapid and low cost. TF-antigen is a tumor-associated antigen displayed on cell surface proteins of a high percentage of human carcinomas. Here we present a fluorometric bioassay for TF-antigen (galactose-β-(1→3)-N-acetyl-d-galactosamine) that utilizes quantum dot (QD) technology coupled with magnetic beads for rapid detection of TF-antigen at high sensitivity (10(-7) M range). In the competitive bioassay, 4-aminophenyl β-d-galactopyranoside (4-APG) conjugated to QDs competes with TF-antigen for binding sites on peanut agglutinin (PNA) that is immobilized on magnetic beads. The bioassay is specific and ultrasensitive in the environment of complex protein mixtures, demonstrating its potential applicability for the screening of clinical samples. PMID:23980999

  10. 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

  11. The impact of cloud vertical profile on liquid water path retrieval based on the bispectral method: A theoretical study based on large-eddy simulations of shallow marine boundary layer clouds

    NASA Astrophysics Data System (ADS)

    Miller, Daniel J.; Zhang, Zhibo; Ackerman, Andrew S.; Platnick, Steven; Baum, Bryan A.

    2016-04-01

    Passive optical retrievals of cloud liquid water path (LWP), like those implemented for Moderate Resolution Imaging Spectroradiometer (MODIS), rely on cloud vertical profile assumptions to relate optical thickness (τ) and effective radius (re) retrievals to LWP. These techniques typically assume that shallow clouds are vertically homogeneous; however, an adiabatic cloud model is plausibly more realistic for shallow marine boundary layer cloud regimes. In this study a satellite retrieval simulator is used to perform MODIS-like satellite retrievals, which in turn are compared directly to the large-eddy simulation (LES) output. This satellite simulator creates a framework for rigorous quantification of the impact that vertical profile features have on LWP retrievals, and it accomplishes this while also avoiding sources of bias present in previous observational studies. The cloud vertical profiles from the LES are often more complex than either of the two standard assumptions, and the favored assumption was found to be sensitive to cloud regime (cumuliform/stratiform). Confirming previous studies, drizzle and cloud top entrainment of dry air are identified as physical features that bias LWP retrievals away from adiabatic and toward homogeneous assumptions. The mean bias induced by drizzle-influenced profiles was shown to be on the order of 5-10 g/m2. In contrast, the influence of cloud top entrainment was found to be smaller by about a factor of 2. A theoretical framework is developed to explain variability in LWP retrievals by introducing modifications to the adiabatic re profile. In addition to analyzing bispectral retrievals, we also compare results with the vertical profile sensitivity of passive polarimetric retrieval techniques.

  12. 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)

  13. 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 ...

  14. Automatic information retrieval of Chinese business card

    NASA Astrophysics Data System (ADS)

    Shi, GuangShun; Pan, Wumo; Jin, Jianming

    2003-01-01

    Document image understanding techniques have been widely used in many application domains. Various kinds of documents have been researched and different methods are developed for information retrieval purpose. In this paper we present a practical method to extract information items from Chinese business card. Before retrieval information in business card, the image of business card had been segmented into little text regions and each text region had been recognized. Because the typeset of business card is variable, and both English and Chinese characters are used, so there are errors in segmentation and recognition result. We focus on building a robust model that can tolerate errors and extract syntax pattern of each text lines in business card, which using both layout information and logical information. By this model, many errors will be identified and adjusted. Finally, correct property will be assigned to each text region in business card, and recognition errors will be corrected.

  15. 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.

  16. 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.

  17. Retrievable IVC Square Stent Filter: Experimental Study

    SciTech Connect

    Pavcnik, Dusan; Uchida, Barry T.; Keller, Frederick S.; Corless, Christopher L.; Roesch, Josef

    1999-05-15

    Purpose: In vitro and in vivo evaluation of a new retrievable, home-made, inferior vena cava (IVC) Square stent filter (SSF) with two trapping levels. Methods: In vitro, the SSF was compared in a flow model with the stainless steel Greenfield filter (SGF) for emboli- trapping efficiency by serially passing 300 emboli of 3 and 6 mm in diameter and 15-30 mm in length in each type of filter. Nine swine were used for the in vivo testing of the SSF for deployment and retrievability, emboli-trapping efficiency, stability, and self-centering ability and two were used (total of 11 swine) for testing repositioning and retrievability of the SSF at 2 weeks and for gross and histologic IVC changes at 2 months. Results: In vitro, the SSF and SGF had similar efficiency in trapping large emboli but the SSF had significantly better efficiency than the SGF for trapping all sizes of emboli (91.7% vs 81%), medium size emboli (93% vs 80%), and small emboli (86% vs 69%). Efficiency decreased in both filters from the first to the fifth embolus in each series but was still significantly better for the SSF. With the SSF, 89% of emboli were caught at the primary and 11% at the secondary filtration level. In the nine animals used for acute studies, the SSF was easily placed in all 27 attempts, assumed a central position 26 times, and was easily retrieved in 21 of 22 attempts. One tilted filter needed additional manipulation for retrieval. During emboli injection in five swine, the SSF had 97.2% emboli-trapping efficiency and demonstrated good stability. In the two animals used for longer-term evaluation, the filters were easily retrieved 2 weeks after implantation. Histologic evaluation at 2 months showed neointimal proliferation around the SSF wires in contact with the IVC wall, which was otherwise normal. Conclusion: The SSF is a promising filter. It is easy to place and retrieve, is stable after placement, and has high efficiency for trapping emboli. Promising results justify further

  18. 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 ) ...

  19. Information retrieval at the millenium.

    PubMed Central

    Hersh, W.

    1998-01-01

    Information retrieval systems were among the first medical informatics applications, yet their use has changed substantially in this decade with the growth of end-user computers and the Internet. While early challenges revolved around how to increase the amount of information available in electronic form, more recent challenges center on how to manage the growing volume. Traditional information retrieval issues--such as how to organize and index information to make it more retrievable as well as how to evaluate the effectiveness of systems--are still as pertinent as ever. PMID:9929180

  20. 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.

  1. 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

  2. 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.

  3. Hierarchical and binary spatial descriptors for lung nodule image retrieval.

    PubMed

    Ng, Gillian; Song, Yang; Cai, Weidong; Zhou, Yun; Liu, Sidong; Feng, David Dagan

    2014-01-01

    With the increasing amount of image data available for cancer staging and diagnosis, it is clear that content-based image retrieval techniques are becoming more important to assist physicians in making diagnoses and tracking disease. Domain-specific feature descriptors have been previously shown to be effective in the retrieval of lung tumors. This work proposes a method to improve the rotation invariance of the hierarchical spatial descriptor, as well as presents a new binary descriptor for the retrieval of lung nodule images. The descriptors were evaluated on the ELCAP public access database, exhibiting good performance overall. PMID:25571476

  4. Diversification of visual media retrieval results using saliency detection

    NASA Astrophysics Data System (ADS)

    Muratov, Oleg; Boato, Giulia; De Natale, Franesco G. B.

    2013-03-01

    Diversification of retrieval results allows for better and faster search. Recently there has been proposed different methods for diversification of image retrieval results mainly utilizing text information and techniques imported from natural language processing domain. However, images contain visual information that is impossible to describe in text and the use of visual features is inevitable. Visual saliency is information about the main object of an image implicitly included by humans while creating visual content. For this reason it is naturally to exploit this information for the task of diversification of the content. In this work we study whether visual saliency can be used for the task of diversification and propose a method for re-ranking image retrieval results using saliency. The evaluation has shown that the use of saliency information results in higher diversity of retrieval results.

  5. 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

  6. 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

  7. [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

  8. 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

  9. 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

  10. 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

  11. Altering the antigenicity of proteins.

    PubMed Central

    Alexander, H; Alexander, S; Getzoff, E D; Tainer, J A; Geysen, H M; Lerner, R A

    1992-01-01

    To better understand the binding interaction between antigen and antibody we need to distinguish protein residues critical to the binding energy and mechanism from residues merely localized in the interface. By analyzing the binding of monoclonal antibodies to recombinant wild-type and mutant myohemerythrin (MHr) proteins, we were able to test the role of individual critical residues at the highly antigenic site MHr-(79-84), within the context of the folded protein. The results directly show the existence of antigenically critical residues, whose mutations significantly reduce antibody binding to the folded protein, thus verifying peptide-based assignments of these critical residues and demonstrating the ability of buried side chains to influence antigenicity. Taken together, these results (i) distinguish the antigenic surface from the solvent-exposed protein surface before binding, (ii) support a two-stage interaction mechanism allowing inducible changes in protein antigens by antibody binding, and (iii) show that protein antigenicity can be significantly reduced by alteration of single critical residues without destroying biological activity. Images PMID:1373498

  12. 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.

  13. 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

  14. Downscaling Thermal Infrared Radiance for Subpixel Land Surface Temperature Retrieval

    PubMed Central

    Liu, Desheng; Pu, Ruiliang

    2008-01-01

    Land surface temperature (LST) retrieved from satellite thermal sensors often consists of mixed temperature components. Retrieving subpixel LST is therefore needed in various environmental and ecological studies. In this paper, we developed two methods for downscaling coarse resolution thermal infrared (TIR) radiance for the purpose of subpixel temperature retrieval. The first method was developed on the basis of a scale-invariant physical model on TIR radiance. The second method was based on a statistical relationship between TIR radiance and land cover fraction at high spatial resolution. The two methods were applied to downscale simulated 990-m ASTER TIR data to 90-m resolution. When validated against the original 90-m ASTER TIR data, the results revealed that both downscaling methods were successful in capturing the general patterns of the original data and resolving considerable spatial details. Further quantitative assessments indicated a strong agreement between the true values and the estimated values by both methods.

  15. Cloud Property Retrieval Products for Graciosa Island, Azores

    SciTech Connect

    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. Quantitative Assessment of Image Retrieval Effectiveness.

    ERIC Educational Resources Information Center

    Smith, John R.

    2001-01-01

    Examines the problems of developing a framework and testbed for quantitative assessment of image retrieval effectiveness. To better harness the extensive research on content-based retrieval and improve capabilities of image retrieval systems, this article advocates the establishment of common image retrieval testbeds consisting of standardized…

  17. Comparison of texture models for efficient ultrasound image retrieval

    NASA Astrophysics Data System (ADS)

    Bansal, Maggi; Sharma, Vipul; Singh, Sukhwinder

    2013-02-01

    Due to availability of inexpensive and easily available image capturing devices, the size of digital image collection is increasing rapidly. Thus, there is need to create efficient access methods or retrieval tools to search, browse and retrieve images from large multimedia repositories. More specifically, researchers have been engaged on different ways of retrieving images based on their actual content. In particular, Content Based Image Retrieval (CBIR) systems have attracted considerable research and commercial interest in the recent years. In CBIR, visual features characterizing the image content are color, shape and texture. Currently, texture is used to quantify the image content of medical images as it is the most prominent feature that contains information about the spatial distribution of gray levels and variations in brightness. Various texture models like Haralick's Spatial Gray Level Co-occurence Matrix (SGLCM), Gray Level Difference Statistics (GLDS), First-order Statistics (FoS), Statistical Feature Matrix (SFM), Law's Texture Energy Measures (TEM), Fractal features and Fourier Power Spectrum (FPS) features exists in literature. Each of these models visualizes texture in a different way. Retrieval performance depends upon the choice of texture algorithm. Unfortunately, there is no texture model known to work best for encoding texture properties of liver ultrasound images or retrieving most similar images. An experimental comparison of different texture models for Content Based Medical Image Retrieval (CBMIR) is presented in this paper. For the experiments, liver ultrasound image database is used and the retrieval performance of the various texture models is analyzed in detail. The paper concludes with recommendations which texture model performs better for liver ultrasound images. Interestingly, FPS and SGLCM based Haralick's features perform well for liver ultrasound retrieval and thus can be recommended as a simple baseline for such images.

  18. Identification and characterization of specific hydatid antigen fraction(s).

    PubMed

    Maher, K M; Kaddah, M A; Hassanein, H I; Shaker, Z A; Khalafallah, A M

    1992-08-01

    A specific hydatid antigen was prepared in this study from Echinococcus granulosus cyst in livers and lungs of camels. Elimination of host "camel" protein from crude hydatid fluid was achieved by two methods: Salting out using ammonium sulfate precipitation method and immunoaffinity purification using coupled anticamel antibody to cyanogenbromide activated sepharose 4B gel. Testing the prepared hydatid antigen against anticamel serum, using immunodiffusion method, indicated that the affinity purified hydatid antigen was almost completely purified from camel protein. Characterization of the affinity purified hydatid antigen, using immunoelectrophoresis, showed positive arc 5 precipitation when tested against known positive antihydatid sera. Further characterization with gradient gel electrophoresis, showed with silver stain that the dominant and most consistently demonstrable proteins occurred as a complex in the 52/62 KDa region. Strong reaction with the 52/62 KDa complex was consistently observed when the affinity purified hydatid antigen was probed with known positive reference antihydatid sera. The identified hydatid antigen fraction(s) with 52/62 KDa complex can provide promising non-invasive parameter for diagnosis of Hydatidosis. PMID:1500792

  19. The Application of ElasticSearch in the Massive Astronomical Data Retrieval

    NASA Astrophysics Data System (ADS)

    Chen, Y. J.; Wang, F.; Deng, H.; Liu, Y. B.

    2016-03-01

    Astronomical observational data are the fundamental element for modern astronomical researches. However, with the rapid increase of astronomical data, the traditional centralized retrieval methods are hard to meet the requirements of high- performance data retrieval. In the study, we present a novel method which is based on the ElasticSearch distributed retrieval engine and River mechanism to create data indexes, and provide high performance data retrieval for massive FITS (Flexible Image Transport System) data. We discuss the key technologies of the nearly real-time retrieval and query. The experimental results show that the method is capable of obtaining high retrieval performance especially for the cases in which the number of the FITS data exceeds millions or even tens of millions. Meanwhile, the method can be easily integrated into the current astronomical data archiving systems, and completely meet the archive requirements of all kinds of astronomical telescope systems.

  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

  1. An update on sperm retrieval techniques for azoospermic males

    PubMed Central

    Esteves, Sandro C; Miyaoka, Ricardo; Orosz, José Eduardo; Agarwal, Ashok

    2013-01-01

    The use of non-ejaculated sperm coupled with intracytoplasmic sperm injection has become a globally established procedure for couples with azoospermic male partners who wish to have biological offspring. Surgical methods have been developed to retrieve spermatozoa from the epididymides and the testes of such patients. This article reviews the methods currently available for sperm acquisition in azoospermia, with a particular focus on the perioperative, anesthetic and technical aspects of these procedures. A critical analysis of the advantages and disadvantages of these sperm retrieval methods is provided, including the authors' methods of choice and anesthesia preferences. PMID:23503959

  2. 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.

  3. Natural Selection Promotes Antigenic Evolvability

    PubMed Central

    Graves, Christopher J.; Ros, Vera I. D.; Stevenson, Brian; Sniegowski, Paul D.; Brisson, Dustin

    2013-01-01

    The hypothesis that evolvability - the capacity to evolve by natural selection - is itself the object of natural selection is highly intriguing but remains controversial due in large part to a paucity of direct experimental evidence. The antigenic variation mechanisms of microbial pathogens provide an experimentally tractable system to test whether natural selection has favored mechanisms that increase evolvability. Many antigenic variation systems consist of paralogous unexpressed ‘cassettes’ that recombine into an expression site to rapidly alter the expressed protein. Importantly, the magnitude of antigenic change is a function of the genetic diversity among the unexpressed cassettes. Thus, evidence that selection favors among-cassette diversity is direct evidence that natural selection promotes antigenic evolvability. We used the Lyme disease bacterium, Borrelia burgdorferi, as a model to test the prediction that natural selection favors amino acid diversity among unexpressed vls cassettes and thereby promotes evolvability in a primary surface antigen, VlsE. The hypothesis that diversity among vls cassettes is favored by natural selection was supported in each B. burgdorferi strain analyzed using both classical (dN/dS ratios) and Bayesian population genetic analyses of genetic sequence data. This hypothesis was also supported by the conservation of highly mutable tandem-repeat structures across B. burgdorferi strains despite a near complete absence of sequence conservation. Diversification among vls cassettes due to natural selection and mutable repeat structures promotes long-term antigenic evolvability of VlsE. These findings provide a direct demonstration that molecular mechanisms that enhance evolvability of surface antigens are an evolutionary adaptation. The molecular evolutionary processes identified here can serve as a model for the evolution of antigenic evolvability in many pathogens which utilize similar strategies to establish chronic infections

  4. Prognostic factors for sperm retrieval in non-obstructive azoospermia.

    PubMed

    Glina, Sidney; Vieira, Marcelo

    2013-01-01

    Testicular sperm retrieval techniques associated with intracytoplasmic sperm injection have changed the field of male infertility treatment and given many azoospermic men the chance to become biological fathers. Despite the current use of testicular sperm extraction, reliable clinical and laboratory prognostic factors of sperm recovery are still absent. The objective of this article was to review the prognostic factors and clinical use of sperm retrieval for men with non-obstructive azoospermia. The PubMed database was searched for the Medical Subject Headings (MeSH) terms azoospermia, sperm retrieval, and prognosis. Papers on obstructive azoospermia were excluded. The authors selected articles that reported successful sperm retrieval techniques involving clinical, laboratory, or parenchyma processing methods. The selected papers were reviewed, and the prognostic factors were discussed. No reliable positive prognostic factors guarantee sperm recovery for patients with non-obstructive azoospermia. The only negative prognostic factor is the presence of AZFa and AZFb microdeletions. PMID:23503961

  5. Pareto-depth for multiple-query image retrieval.

    PubMed

    Hsiao, Ko-Jen; Calder, Jeff; Hero, Alfred O

    2015-02-01

    Most content-based image retrieval systems consider either one single query, or multiple queries that include the same object or represent the same semantic information. In this paper, we consider the content-based image retrieval problem for multiple query images corresponding to different image semantics. We propose a novel multiple-query information retrieval algorithm that combines the Pareto front method with efficient manifold ranking. We show that our proposed algorithm outperforms state of the art multiple-query retrieval algorithms on real-world image databases. We attribute this performance improvement to concavity properties of the Pareto fronts, and prove a theoretical result that characterizes the asymptotic concavity of the fronts. PMID:25494509

  6. 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.

    2014-12-01

    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 were 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, a fitting window and a polynomial degree are determined. Two different approaches to reduce the interference of liquid water absorption over oceanic regions are evaluated, achieving significant reduction of the number of negative columns over clear water regions. The impact of using different absorption cross-sections for water vapour is evaluated and only small differences are found. Finally, a high-temperature (boundary layer ambient: 294 K) 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 GOME-2 and SCIAMACHY measurements over continental regions is performed, showing overall good consistency. However, SCIAMACHY CHOCHO columns are systematically higher than those obtained from the other instruments. 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 Russia between mid-July and mid-August 2010. In both cases, enhanced CHOCHO levels are found in close spatial and temporal proximity to elevated levels of MODIS fire radiative power, demonstrating that pyrogenic emissions can be clearly identified in the new OMI CHOCHO product.

  7. Aerosol property retrieval from geostationary observations

    NASA Astrophysics Data System (ADS)

    Govaerts, Yves

    The Meteosat satellites play an important role for the generation of consistent long time series of aerosol properties. This importance relies on (i) the long duration of past (Meteosat First Generation, MFG) starting in 1982, present (Meteosat Second Generation, MSG) and future (Meteosat Third Generation, MTG) missions and (ii) their frequent cycle of acquisition that can be used to document the anisotropy of the surface and therefore the lower boundary condition for aerosol retrieval over land surfaces. Hence, a similar approach is used for the processing of each Meteosat generation based on a joint retrieval of surface reflectance and aerosol properties using an Optimal Estimation approach. Daily accumulation of the frequent Meteosat observations is used to discriminate the radiative effects that result from the surface anisotropy, from those caused by the aerosol scattering. The inverted forward model explicitly accounts for the surface anisotropy and the multiple scattering for the coupled surface-atmosphere system. Pinty et al. (2000) pioneered with the development of an original method to characterise simultaneously surface anisotropy and atmospheric scattering properties for the processing of MFG. Although these observations are limited to one single large VIS band poorly characterised, the main advantage of MFG relies in the duration of the archive (1982 - 2006), knowing that prior to 2000 space observations were very scarce. Despite these radiometric limitations, it is possible to detect major aerosol events like dust storms, fire plumes or pollution events, even over land surfaces. SEVIRI, on-board MSG, offers additional capabilities with its three solar channels and 15 min repeat cycle. AOD retrieval is much more accurate than with MFG and it is possible to discriminate among various aerosol classes. The additional FCI solar channels on-board MTG will offer improved capabilities with respect to MSG/SEVIRI for the retrieval of aerosol concentration and

  8. Aptamer-targeted Antigen Delivery

    PubMed Central

    Wengerter, Brian C; Katakowski, Joseph A; Rosenberg, Jacob M; Park, Chae Gyu; Almo, Steven C; Palliser, Deborah; Levy, Matthew

    2014-01-01

    Effective therapeutic vaccines often require activation of T cell-mediated immunity. Robust T cell activation, including CD8 T cell responses, can be achieved using antibodies or antibody fragments to direct antigens of interest to professional antigen presenting cells. This approach represents an important advance in enhancing vaccine efficacy. Nucleic acid aptamers present a promising alternative to protein-based targeting approaches. We have selected aptamers that specifically bind the murine receptor, DEC205, a C-type lectin expressed predominantly on the surface of CD8α+ dendritic cells (DCs) that has been shown to be efficient at facilitating antigen crosspresentation and subsequent CD8+ T cell activation. Using a minimized aptamer conjugated to the model antigen ovalbumin (OVA), DEC205-targeted antigen crosspresentation was verified in vitro and in vivo by proliferation and cytokine production by primary murine CD8+ T cells expressing a T cell receptor specific for the major histocompatibility complex (MHC) I-restricted OVA257–264 peptide SIINFEKL. Compared with a nonspecific ribonucleic acid (RNA) of similar length, DEC205 aptamer-OVA-mediated antigen delivery stimulated strong proliferation and production of interferon (IFN)-γ and interleukin (IL)-2. The immune responses elicited by aptamer-OVA conjugates were sufficient to inhibit the growth of established OVA-expressing B16 tumor cells. Our results demonstrate a new application of aptamer technology for the development of effective T cell-mediated vaccines. PMID:24682172

  9. Using radiance of cloud shadow for retrieve Investigation of AOD retrieval with Himawari-8 satellite data

    NASA Astrophysics Data System (ADS)

    Sun, Ta-Min; Chang, Yuan-Hsiang; Chang, Kuo-En; Lin, Tang-Huang

    2016-04-01

    As we know, the emission of pollutants, such as dust storm, biomass burning and anthropogenic pollution are serious issues related to the environmental change and human health topics in Asia. With the high temporal observation over a broad area, the new generated geostationary satellite, Himawari-8 (H-8) seems to be a good choice for atmospheric pollution monitor. It can provide the observation over Asia with 16 bands in visible and thermal infrared spectral every 10 minutes. For the atmospheric pollutant monitor by means of remote sensing, the retrieval of aerosol optical depth (AOD) is the most important index. In this study, the long method is employed for AOD retrieval which depends on the path radiance significantly. Apparent radiance of the suitable cloud shadow is selected as the path radiance. In order to let the atmospheric pollution monitor is used efficiently, so the distribution of the path radiance is using the objective analysis to expand it. The results of AOD retrieval from H-8 visible data are well consistent with MODIS (Moderate Resolution Imaging Spectroradiometer) AOD products and ground measurements AERONET (Aerosol Robotic Networks), indicating the practical of proposed approach for the AOD retrieval with H-8 data.

  10. The 183-WSL fast rain rate retrieval algorithm: Part I: Retrieval design

    NASA Astrophysics Data System (ADS)

    Laviola, Sante; Levizzani, Vincenzo

    2011-03-01

    The Water vapour Strong Lines at 183 GHz (183-WSL) fast retrieval method retrieves rain rates and classifies precipitation types for applications in nowcasting and weather monitoring. The retrieval scheme consists of two fast algorithms, over land and over ocean, that use the water vapour absorption lines at 183.31 GHz corresponding to the channels 3 (183.31 ± 1 GHz), 4 (183.31 ± 3 GHz) and 5 (183.31 ± 7 GHz) of the Advanced Microwave Sounding Unit module B (AMSU-B) and of the Microwave Humidity Sounder (MHS) flying on NOAA-15-18 and Metop-A satellite series, respectively. The method retrieves rain rates by exploiting the extinction of radiation due to rain drops following four subsequent steps. After ingesting the satellite data stream, the window channels at 89 and 150 GHz are used to compute scattering-based thresholds and the 183-WSLW module for rainfall area discrimination and precipitation type classification as stratiform or convective on the basis of the thresholds calculated for land/mixed and sea surfaces. The thresholds are based on the brightness temperature difference Δwin = TB89 - TB150 and are different over land (L) and over sea (S): cloud droplets and water vapour (Δwin < 3 K L; Δwin < 0 K S), stratiform rain (3 K < Δwin < 10 K L; 0 K < Δwin < 10 K S), and convective rain (Δwin > 10 K L and S). The thresholds, initially empirically derived from observations, are corroborated by the simulations of the RTTOV radiative transfer model applied to 20000 ECMWF atmospheric profiles at midlatitudes and the use of data from the Nimrod radar network. A snow cover mask and a digital elevation model are used to eliminate false rain area attribution, especially over elevated terrain. A probability of detection logistic function is also applied in the transition region from no-rain to rain adjacent to the clouds to ensure continuity of the rainfall field. Finally, the last step is dedicated to the rain rate retrieval with the modules 183-WSLS (stratiform

  11. Texture image retrieval using new rotated complex wavelet filters.

    PubMed

    Kokare, Manesh; Biswas, P K; Chatterji, B N

    2005-12-01

    A new set of two-dimensional (2-D) rotated complex wavelet filters (RCWFs) are designed with complex wavelet filter coefficients, which gives texture information strongly oriented in six different directions (45 degrees apart from complex wavelet transform). The 2-D RCWFs are nonseparable and oriented, which improves characterization of oriented textures. Most texture image retrieval systems are still incapable of providing retrieval result with high retrieval accuracy and less computational complexity. To address this problem, we propose a novel approach for texture image retrieval by using a set of dual-tree rotated complex wavelet filter (DT-RCWF) and dual-tree-complex wavelet transform (DT-CWT) jointly, which obtains texture features in 12 different directions. The information provided by DT-RCWF complements the information generated by DT-CWT. Features are obtained by computing the energy and standard deviation on each subband of the decomposed image. To check the retrieval performance, texture database D1 of 1856 textures from Brodatz album and database D2 of 640 texture images from VisTex image database is created. Experimental results indicates that the proposed method improves retrieval rate from 69.61% to 77.75% on database D1, and from 64.83% to 82.81% on database D2, in comparing with traditional discrete wavelet transform based approach. The proposed method also retains comparable levels of computational complexity. PMID:16366243

  12. A Probabilistic Analysis of Sparse Coded Feature Pooling and Its Application for Image Retrieval

    PubMed Central

    Zhang, Yunchao; Chen, Jing; Huang, Xiujie; Wang, Yongtian

    2015-01-01

    Feature coding and pooling as a key component of image retrieval have been widely studied over the past several years. Recently sparse coding with max-pooling is regarded as the state-of-the-art for image classification. However there is no comprehensive study concerning the application of sparse coding for image retrieval. In this paper, we first analyze the effects of different sampling strategies for image retrieval, then we discuss feature pooling strategies on image retrieval performance with a probabilistic explanation in the context of sparse coding framework, and propose a modified sum pooling procedure which can improve the retrieval accuracy significantly. Further we apply sparse coding method to aggregate multiple types of features for large-scale image retrieval. Extensive experiments on commonly-used evaluation datasets demonstrate that our final compact image representation improves the retrieval accuracy significantly. PMID:26132080

  13. Retrieval of a Dislodged Catheter Using Combined Fluoroscopy and Intracardiac Echocardiography

    PubMed Central

    Mitsopoulos, Gus; Hanna, Robert F.; Brejt, Sidney Z.; Goldstein, Greg E.; Sheynzon, Vladimir; Weintraub, Joshua L.; Gray, William A.

    2015-01-01

    This report details a method of percutaneous, transluminal retrieval of an intracardiac foreign body using fluoroscopy in combination with intracardiac echocardiography. During retrieval, intracardiac echocardiography (ICE) provided real-time anatomic localization of a constantly moving, almost radiolucent micropuncture coaxial dilator fragment with respect to the tricuspid and pulmonary valves. This method may serve as a crucial aid in retrieval of intracardiac foreign bodies that are difficult to see with fluoroscopy and which may be adjacent to cardiac valves. PMID:26075131

  14. Retrieval of atmospheric methane from high spectral resolution satellite measurements: a correction for cirrus cloud effects.

    PubMed

    Bril, Andrey; Oshchepkov, Sergey; Yokota, Tatsuya

    2009-04-10

    We assessed the accuracy of methane (CH(4)) retrievals from synthetic radiance spectra particular to Greenhouse Gases Observing Satellite observations. We focused on estimating the CH(4) vertical column amount from an atmosphere that includes thin cirrus clouds, taking into account uncertain meteorological conditions. A photon path-length probability density function (PPDF)-based method was adapted to correct for atmospheric scattering effects in CH(4) retrievals. This method was shown to provide similar retrieval accuracy as compared to a carbon dioxide (CO(2))-proxy-based correction approach. It infers some advantages of PPDF-based method for methane retrievals under high variability of CO(2) abundance. PMID:19363553

  15. Retrieval for color artistry concepts.

    PubMed

    Lay, Jose A; Guan, Ling

    2004-03-01

    This paper presents a work on the retrieval of artworks for color artistry concepts. First we affirm the view that the Query-by-Example paradigm fundamental to the current content-based retrieval systems is able to extend only limited usefulness. We then propose a concept-based retrieval engine based on the generative grammar of elemental concepts methodology. In the latter, the language by which color artistry concepts are communicated in artworks is used to operate semantic searches. The color artistry language is explicated into elemental concepts and the associated generative grammar. The elemental concepts are used to index the artworks, while the generative grammar is used to facilitate post-coordinate expression of color artistry concept queries by using the elemental concepts. PMID:15376925

  16. Comparisons of Upper Tropospheric Humidity Retrievals from TOVS and METEOSAT

    NASA Technical Reports Server (NTRS)

    Escoffier, C.; Bates, J.; Chedin, A.; Rossow, W. B.; Schmetz, J.

    1999-01-01

    Two different methods for retrieving Upper Tropospheric Humidities (UTH) from the TOVS (TIROS Operational Vertical Sounder) instruments aboard NOAA polar orbiting satellites are presented and compared. The first one, from the Environmental Technology Laboratory, computed by J. Bates and D. Jackson (hereafter BJ method), estimates UTH from a simplified radiative transfer analysis of the upper tropospheric infrared water vapor channel at wavelength measured by HIRS (6.3 micrometer). The second one results from a neural network analysis of the TOVS (HIRS and MSU) data developed at, the Laboratoire de Meteorologie Dynamique (hereafter the 3I (Improved Initialization Inversion) method). Although the two methods give very similar retrievals in temperate regions (30-60 N and S), an absolute bias up to 16% appears in the convective zone of the tropics. The two datasets have also been compared with UTH retrievals from infrared radiance measurements in the 6.3 micrometer channel from the geostationary satellite METEOSAT (hereafter MET method). The METEOSAT retrievals are systematically drier than the TOVS-based results by an absolute bias between 5 and 25%. Despite the biases, the spatial and temporal correlations are very good. The purpose of this study is to explain the deviations observed between the three datasets. The sensitivity of UTH to air temperature and humidity profiles is analysed as are the clouds effects. Overall, the comparison of the three retrievals gives an assessment of the current uncertainties in water vapor amounts in the upper troposphere as determined from NOAA and METEOSAT satellites.

  17. Accelerated Adaptive MGS Phase Retrieval

    NASA Technical Reports Server (NTRS)

    Lam, Raymond K.; Ohara, Catherine M.; Green, Joseph J.; Bikkannavar, Siddarayappa A.; Basinger, Scott A.; Redding, David C.; Shi, Fang

    2011-01-01

    The Modified Gerchberg-Saxton (MGS) algorithm is an image-based wavefront-sensing method that can turn any science instrument focal plane into a wavefront sensor. MGS characterizes optical systems by estimating the wavefront errors in the exit pupil using only intensity images of a star or other point source of light. This innovative implementation of MGS significantly accelerates the MGS phase retrieval algorithm by using stream-processing hardware on conventional graphics cards. Stream processing is a relatively new, yet powerful, paradigm to allow parallel processing of certain applications that apply single instructions to multiple data (SIMD). These stream processors are designed specifically to support large-scale parallel computing on a single graphics chip. Computationally intensive algorithms, such as the Fast Fourier Transform (FFT), are particularly well suited for this computing environment. This high-speed version of MGS exploits commercially available hardware to accomplish the same objective in a fraction of the original time. The exploit involves performing matrix calculations in nVidia graphic cards. The graphical processor unit (GPU) is hardware that is specialized for computationally intensive, highly parallel computation. From the software perspective, a parallel programming model is used, called CUDA, to transparently scale multicore parallelism in hardware. This technology gives computationally intensive applications access to the processing power of the nVidia GPUs through a C/C++ programming interface. The AAMGS (Accelerated Adaptive MGS) software takes advantage of these advanced technologies, to accelerate the optical phase error characterization. With a single PC that contains four nVidia GTX-280 graphic cards, the new implementation can process four images simultaneously to produce a JWST (James Webb Space Telescope) wavefront measurement 60 times faster than the previous code.

  18. Multimedia Information Retrieval Literature Review

    SciTech Connect

    Wong, Pak C.; Bohn, Shawn J.; Payne, Deborah A.

    2010-10-12

    This survey paper highlights some of the recent, influential work in multimedia information retrieval (MIR). MIR is a branch area of multimedia (MM). The young and fast-growing area has received strong industrial and academic support in the United States and around the world (see Section 7 for a list of major conferences and journals of the community). The term "information retrieval" may be misleading to those with different computer science or information technology backgrounds. As shown in our discussion later, it indeed includes topics from user interaction, data analytics, machine learning, feature extraction, information visualization, and more.

  19. Information retrieval for patient care.

    PubMed Central

    Gardner, M.

    1997-01-01

    Doctors need clinical information during most consultations with patients, and much of this need could be satisfied by material from online sources. Advances in data communication technologies mean that multimedia information can be transported rapidly to various clinical care locations. However, selecting the few items of information likely to be useful in a particular clinical situation from the mass of information available is a major problem. Current information retrieval systems are designed primarily for use in research rather than clinical care. The design, implementation, and critical evaluation of new information retrieval systems for clinical care should be guided by knowledgeable clinical users. PMID:9099122

  20. Publication search and retrieval system

    USGS Publications Warehouse

    Winget, Elizabeth A.

    1981-01-01

    The publication search and retrieval system of the Branch of Atlantic-Gulf of Mexico Geology, U.S. Geological Survey, Woods Hole, Mass., is a procedure for listing and describing branch-sponsored publications. It is designed for maintenance and retrieval by those having limited knowledge of computer languages and programs. Because this branch currently utilizes the Hewlett-Packard HP-1000 computer with RTE-IVB operating system, database entry and maintenance is performed in accordance with the TE-IVB Terminal User’s Reference Manual (Hewlett-Packard Company, 1980) and within the constraints of GRASP (Bowen and Botbol, 1975) and WOLF (Evenden, 1978).