277 research outputs found

    Registration and Fusion of Multi-Spectral Images Using a Novel Edge Descriptor

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    In this paper we introduce a fully end-to-end approach for multi-spectral image registration and fusion. Our method for fusion combines images from different spectral channels into a single fused image by different approaches for low and high frequency signals. A prerequisite of fusion is a stage of geometric alignment between the spectral bands, commonly referred to as registration. Unfortunately, common methods for image registration of a single spectral channel do not yield reasonable results on images from different modalities. For that end, we introduce a new algorithm for multi-spectral image registration, based on a novel edge descriptor of feature points. Our method achieves an accurate alignment of a level that allows us to further fuse the images. As our experiments show, we produce a high quality of multi-spectral image registration and fusion under many challenging scenarios

    Visual Recognition and Categorization on the Basis of Similarities to Multiple Class Prototypes

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    To recognize a previously seen object, the visual system must overcome the variability in the object's appearance caused by factors such as illumination and pose. Developments in computer vision suggest that it may be possible to counter the influence of these factors, by learning to interpolate between stored views of the target object, taken under representative combinations of viewing conditions. Daily life situations, however, typically require categorization, rather than recognition, of objects. Due to the open-ended character both of natural kinds and of artificial categories, categorization cannot rely on interpolation between stored examples. Nonetheless, knowledge of several representative members, or prototypes, of each of the categories of interest can still provide the necessary computational substrate for the categorization of new instances. The resulting representational scheme based on similarities to prototypes appears to be computationally viable, and is readily mapped onto the mechanisms of biological vision revealed by recent psychophysical and physiological studies

    Clobetasol 17-Propionate Cream as an Effective Preventive Treatment for Drug Induced Superficial Thrombophlebitis

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    Commonly used therapies for thrombophlebitis have a high failure rate. There are scant data on the application  of topical corticosteroids to treat thrombophlebitis. The present study investigated if the potent topical  corticosteroid clobetasol 17-propionate cream (Dermovate, Glaxo Wellcome) can be an effective treatment  for drug-induced thrombophlebitis. DP-b99, a neuroprotective agent currently undergoing development for acute stroke, can cause injectionsite  phlebitis. DP-b99 was administered at doses of 1 and 2 mg/kg by a 1 hour intravenous infusion into the  lateral ear vein of groups of 6 and 5 rabbits, respectively. Each rabbit served as its own control by injecting  both ears with DP-b99, while treating only one ear with clobetasol cream immediately after treatment, with  subsequent applications twice daily for 3 days. Phlebitis was evaluated 1, 3, 5, 24, 32, 48, 56 and 72 hours  after DP-b99 treatment using a clinical score ranging from 0 (no reaction) to 4. After 3 days the rabbits were  sacrificed for histological analysis of the ears. The phlebitis score was highest at 24 hours. Clobetasol treatment reduced the clinical scores at all time points and shortened the course of phlebitis. Maximal effect was observed 24-48 hours after the first application  of clobetasol cream. Histologically, there were fewer cases of thrombophlebitis in the clobetasoltreated  ears, and those seen were milder and more focal. To the best of the authors’ knowledge this appears  to be the only study to report a phlebitis-ameliorating effect of a topical corticosteroid.

    Deep Multi-Spectral Registration Using Invariant Descriptor Learning

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    In this paper, we introduce a novel deep-learning method to align cross-spectral images. Our approach relies on a learned descriptor which is invariant to different spectra. Multi-modal images of the same scene capture different signals and therefore their registration is challenging and it is not solved by classic approaches. To that end, we developed a feature-based approach that solves the visible (VIS) to Near-Infra-Red (NIR) registration problem. Our algorithm detects corners by Harris and matches them by a patch-metric learned on top of CIFAR-10 network descriptor. As our experiments demonstrate we achieve a high-quality alignment of cross-spectral images with a sub-pixel accuracy. Comparing to other existing methods, our approach is more accurate in the task of VIS to NIR registration

    The natural history of secondary muscle-invasive bladder cancer

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    BACKGROUND: The management of patients with high-grade non muscle invasive bladder cancer (NMIBC) brings diagnostic and therapeutic challenges. In the current study, we sought to study the natural history of progression to "secondary" muscle-invasive bladder cancer (MIBC)-cancer that developed during follow up of patients presenting with non-muscle invasive bladder cancer (NMIBC). METHODS: Between 1998 and 2008, 760 patients were treated for bladder cancer. Primary MIBC (>=T2) tumors (present upon presentation) were diagnosed in 114 patients. All patients with high-grade NMIBC were treated with intravesical BCG. Mean follow-up was 44 months. RESULTS: Forty patients (6.1%) developed secondary MIBC after a mean period of 21 months from initial diagnosis of bladder cancer. The 2- and 5-year disease-specific survival rates were better for patients with secondary MIBC (90% and 56% compared to 69% and 42% for patients with primary disease, p=0.03). The Kaplan-Meier curves of the two groups were parallel but displaced by approximately 2 years. CONCLUSION: In the current series, MIBC progression occurred among initially presenting patients with NMIBC in 6.1%. In most patients, the initial diagnosis of NMIBC is correct and muscle invasion occurs after a mean period of about 2 years. This supports a non-radical approach in patients with high-grade T1, Ta or Tis. Meticulous follow-up with liberal biopsy of any suspicious lesion may provide early diagnosis of invasive disease

    A novel PTFE-based proton-conductive membrane

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    Abstract The demand for a solid polymer electrolyte membrane (SPEM) for fuel-cell systems, capable of withstanding temperatures above 130 • C, decreasing the electrode-catalyst loadings and reducing poisoning by carbon monoxide, has prompted this study. A novel, low-cost, highly conductive, nanoporous proton-conducting membrane (NP-PCM) based on a polytetrafluoroethylene (PTFE) backbone has been developed. It comprises non-conductive nano-size ceramic powder, PTFE binder and an aqueous acid. The preparation procedures were studied and the membrane was characterized with the use of: SEM, EDS, pore-size-distribution measurements (PSD), TGA-DTA and electrochemical methods. The ionic conductivity of a membrane doped with 3 M sulfuric acid increases with the ceramic powder content and reaches 0.22 S cm −1 at 50% (v/v) silica. A non-optimized direct-methanol fuel cell (DMFC) with a 250 m thick membrane has been assembled. It demonstrated 50 and 130 mW cm −2 at 80 and 130 • C, respectively. Future study will be directed to improving the membrane-preparation process, getting thinner membranes and using this membrane in a hydrogen-fed fuel cell

    Is radical cystectomy mandatory in every patient with variant histology of bladder cancer

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    Urothelial carcinomas have an established propensity for divergent differentiation. Most of these variant tumors are muscle invasive but not all. The response of non muscle invasive variant tumors to intravesical immunotherapy with BCG is not established in the literature, and is reported here. Between June 1995 and December 2007, 760 patients (mean age of 67.5 years) underwent transurethral resection of first time bladder tumors in our institution. Histologically variant tumors were found in 79 patients (10.4%). Of these 57 patients (72%) of them had muscle-invasive disease or extensive non-muscle invasive tumors and remaining 22 patients (28%) were treated with BCG immunotherapy. These included 7 patients with squamous differentiation, 4 with glandular, 6 with nested, 4 with micropapillary and 1 patient with sarcomatoid variant. The response of these patients to immunotherapy was compared with that of 144 patients having high-grade conventional urothelial carcinomas. Median follow-up was 46 months. The 2 and 5-year progression (muscle-invasion) free survival rates were 92% and 84.24% for patients with conventional carcinoma compared to 81.06% and 63.16% for patients with variant disease (P=0.02). The 2 and 5-year disease specific survival rates were 97% and 91.43% for patients with conventional carcinoma compared to 94.74 % and 82% for patients with variant disease (P=0.33). 5 patients (22.7%) of variant group and 13 patients (9.03%) of conventional group underwent cystectomy during follow-up (P=0.068)

    Out of Sight but Not out of Mind: Alternative Means of Communication in Plants

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    Current knowledge suggests that the mechanisms by which plants communicate information take numerous forms. Previous studies have focussed their attention on communication via chemicals, contact and light; other methods of interaction between plants have remained speculative. In this study we tested the ability of young chilli plants to sense their neighbours and identify their relatives using alternative mechanism(s) to recognised plant communication pathways. We found that the presence of a neighbouring plant had a significant influence on seed germination even when all known sources of communication signals were blocked. Furthermore, despite the signalling restriction, seedlings allocated energy to their stem and root systems differently depending on the identity of the neighbour. These results provide clear experimental evidence for the existence of communication channels between plants beyond those that have been recognized and studied thus far
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