47 research outputs found

    Association-based image retrieval

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    With advances in the computer technology and the World Wide Web there has been an explosion in the amount and complexity of multimedia data that are generated, stored, transmitted, analyzed, and accessed. In order to extract useful information from this huge amount of data, many content-based image retrieval (CBIR) systems have been developed in the last decade. A typical CBIR system captures image features that represent image properties such as color, texture, or shape of objects in the query image and try to retrieve images from the database with similar features. Recent advances in CBIR systems include relevance feedback based interactive systems. The main advantage of CBIR systems with relevance feedback is that these systems take into account the gap between the high-level concepts and low-level features and subjectivity of human perception of visual content. In this paper, we propose a new approach for image storage and retrieval called association-based image retrieval (ABIR). We try to mimic human memory. The human brain stores and retrieves images by association. We use a generalized bi-directional associative memory (GBAM) to store associations between feature vectors. The results of our simulation are presented in the paper

    Association-based image retrieval for automatic target recognition.

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    Model-based automatic target recognition (ATR)systems deal with recognizing three dimensional objects from two dimensional images. In order to recognizeand identify objects the ATRsystem must have one or more stored models. Multiple two dimensional views of each three dimensional objectthat may appear in the universe it deals withare stored in the database. During recognition, two dimensional view of atarget object is used a query image and the search is carried out to identify the corresponding three dimensional object. Stages of a model-based ATR system include preprocessing, segmentation, feature extraction, and searching thedatabase. One of the most important problems in a model-based ATR system is to access themost likely candidate model rapidly from a large database. In this paper we propose new architecture for a model-based ATR systemthat is based on association-based image retrieval. We try to mimic human memory. The human brain retrieves images by association. We use generalized bi-directional associative memories to retrieve associated images from the database. We use the ATR system to identify military vehicles from their two dimensional views

    Prevalence of HLA-B*5701 in a Kenyan population with HIV infection

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    We read with interest the article published in your Journal entitled “Real-world persistence with antiretroviral therapy for HIV in the United Kingdom: a multicentre retrospective cohort study”1 which concluded that treatment discontinuation attributable to toxicity profile is not an uncommon event. They also acknowledged lack of data collection on HLA-B*5701 status, which would heavily influence initial ART regimen and the choice to discontinue medication. Of the 25.6 million living with Human Immunodeficiency Virus (HIV) in Africa, an estimated 1.6 million people live in Kenya.2 With an HIV prevalence of 5.6%, Kenya has upscaled HIV treatment and care in the past 10 years to cover 80% of those requiring therapy.2 The current Kenyan guidelines, as in the case of many developing countries, rely on WHO guidelines.3,4 Abacavir is a nucleoside reverse transcriptase inhibitor (NRTI) used for treating HIV infection and is recommended as both first and second line drug options. A barrier to prescribing of abacavir in Kenya is the fear of Abacavir Hypersensitivity Reaction, and this has been compounded by the lack of availability of testing for HLA-B*5701 testing. The Kenyan population is heterogeneous, consisting of 42 tribes with the main ethnic groups being Bantu, Nilotes and Cushites. In our study, we have determined the prevalence of HLAB* 5701 in the black HIV positive population in Kenya using a cross sectional epidemiological survey. We recruited 1004 patients from three HIV centers: the Aga Khan University Hospital Nairobi, Mbagathi Hospital and Machakos Hospital in Kenya after ethics approval was sought from the Research Ethics Committee in Aga Khan University and from the ethics boards of Mbagathi and Machakos hospitals

    NiF2 nanorod arrays for supercapattery applications

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    A electrode for energy storage cells is possible directly on Ni foam, using a simple reduction process to form NiF2 nanorod arrays (NA). We demonstrate NiF2@Ni NA for a symmetric electrochemical supercapattery electrode. With an areal specific capacitance of 51 F cm–2 at 0.25 mA cm–2 current density and 94% cycling stability, a NiF2@Ni electrode can exhibit supercapattery behavior, a combination of supercapacitor and battery-like redox. The symmetric electrochemical supercapattery delivers 31 W h m–2 energy density and 797 W m–2 power density with 83% retention in a 1 M KOH electrolyte, constituting a step toward manufacturing a laboratory-scale energy storage device based on metal halides. Producing self-grown hierarchically porous nanostructured electrodes on three-dimensional metal foams by displacement reactions may be useful for other metal halides as electrodes for supercapacitors, supercapatteries, and lithium-ion batteries

    Relationship between Antibody Susceptibility and Lipopolysaccharide O-Antigen Characteristics of Invasive and Gastrointestinal Nontyphoidal Salmonellae Isolates from Kenya

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    Background: Nontyphoidal Salmonellae (NTS) cause a large burden of invasive and gastrointestinal disease among young children in sub-Saharan Africa. No vaccine is currently available. Previous reports indicate the importance of the O-antigen of Salmonella lipopolysaccharide for virulence and resistance to antibody-mediated killing. We hypothesised that isolates with more O-antigen have increased resistance to antibody-mediated killing and are more likely to be invasive than gastrointestinal. Methodology/Principal findings: We studied 192 NTS isolates (114 Typhimurium, 78 Enteritidis) from blood and stools, mostly from paediatric admissions in Kenya 2000-2011. Isolates were tested for susceptibility to antibody-mediated killing, using whole adult serum. O-antigen structural characteristics, including O-acetylation and glucosylation, were investigated. Overall, isolates were susceptible to antibody-mediated killing, but S. Enteritidis were less susceptible and expressed more O-antigen than Typhimurium (p\u3c0.0001 for both comparisons). For S. Typhimurium, but not Enteritidis, O-antigen expression correlated with reduced sensitivity to killing (r = 0.29, 95% CI = 0.10-0.45, p = 0.002). Both serovars expressed O-antigen populations ranging 21-33 kDa average molecular weight. O-antigen from most Typhimurium were O-acetylated on rhamnose and abequose residues, while Enteritidis O-antigen had low or no O-acetylation. Both Typhimurium and Enteritidis O-antigen were approximately 20%-50% glucosylated. Amount of S. Typhimurium O-antigen and O-antigen glucosylation level were inversely related. There was no clear association between clinical presentation and antibody susceptibility, O-antigen level or other O-antigen features. Conclusion/Significance: Kenyan S. Typhimurium and Enteritidis clinical isolates are susceptible to antibody-mediated killing, with degree of susceptibility varying with level of O-antigen for S. Typhimurium. This supports the development of an antibody-inducing vaccine against NTS for Africa. No clear differences were found in the phenotype of isolates from blood and stool, suggesting that the same isolates can cause invasive disease and gastroenteritis. Genome studies are required to understand whether invasive and gastrointestinal isolates differ at the genotypic level

    Neoadjuvant treatment of pancreatic adenocarcinoma: a systematic review and meta-analysis of 5520 patients

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