73 research outputs found

    A Joint Intensity and Depth Co-Sparse Analysis Model for Depth Map Super-Resolution

    Full text link
    High-resolution depth maps can be inferred from low-resolution depth measurements and an additional high-resolution intensity image of the same scene. To that end, we introduce a bimodal co-sparse analysis model, which is able to capture the interdependency of registered intensity and depth information. This model is based on the assumption that the co-supports of corresponding bimodal image structures are aligned when computed by a suitable pair of analysis operators. No analytic form of such operators exist and we propose a method for learning them from a set of registered training signals. This learning process is done offline and returns a bimodal analysis operator that is universally applicable to natural scenes. We use this to exploit the bimodal co-sparse analysis model as a prior for solving inverse problems, which leads to an efficient algorithm for depth map super-resolution.Comment: 13 pages, 4 figure

    Model-based learning of local image features for unsupervised texture segmentation

    Full text link
    Features that capture well the textural patterns of a certain class of images are crucial for the performance of texture segmentation methods. The manual selection of features or designing new ones can be a tedious task. Therefore, it is desirable to automatically adapt the features to a certain image or class of images. Typically, this requires a large set of training images with similar textures and ground truth segmentation. In this work, we propose a framework to learn features for texture segmentation when no such training data is available. The cost function for our learning process is constructed to match a commonly used segmentation model, the piecewise constant Mumford-Shah model. This means that the features are learned such that they provide an approximately piecewise constant feature image with a small jump set. Based on this idea, we develop a two-stage algorithm which first learns suitable convolutional features and then performs a segmentation. We note that the features can be learned from a small set of images, from a single image, or even from image patches. The proposed method achieves a competitive rank in the Prague texture segmentation benchmark, and it is effective for segmenting histological images

    Validation of the German version of the Mediterranean Diet Adherence Screener (MEDAS) questionnaire

    Get PDF
    Background: Health benefits of the Mediterranean Diet (MD) have been shown in different at-risk populations. A German translation of the Mediterranean Diet Adherence Screener (MEDAS) from the PREvencion con DIeta MEDiterranea (PREDIMED) consortium was used in the LIBRE study, investigating effects of lifestyle-intervention on women with BRCA1/2 mutations. The purpose of the present study is to validate the MEDAS German version. Methods: LIBRE is a multicentre (three university hospitals during this pilot phase), unblinded, randomized, controlled clinical trial. Women with a BRCA1/2 mutation of age 18 or over who provided written consent were eligible for the trial. As part of the assessment, all were given a full-length Food Frequency Questionnaire (FFQ) and MEDAS at baseline and after 3 months. Data derived from FFQ was compared to MEDAS in order to evaluate agreement or concordance between the two questionnaires. Additionally, the association of dietary intake biomarkers in the blood (beta-carotene, omega-3, omega-6 and omega-9 fatty acids and high-sensitivity C-reactive protein (hsCRP)) with some MEDAS items was analyzed using t-Tests and a multivariate regression. Results: The participants of the LIBRE pilot study were 68 in total (33 Intervention, 35 Control). Only participants who completed both questionnaires were included in this analysis (baseline: 66, month three: 54). The concordance between these two questionnaires varied between the items (Intraclass correlation coefficient of 0.91 for pulses at the highest and -0.33 for sugar-sweetened drinks). Mean MEDAS scores (sum of all items) were 9% higher than their FFQ counter-parts at baseline and 15% after 3 months. Higher fish consumption (at least 3 portions) was associated with lower omega-6 fatty acid levels (p = 0.026) and higher omega-3 fatty acid levels (p = 0.037), both results being statistically significant. Conclusions: We conclude that the German MEDAS in its current version could be a useful tool in clinical trials and in practice to assess adherence to MD

    Nucleic acid binding agents exert local toxic effects on neurites via a non-nuclear mechanism

    Full text link
    The mechanism by which drugs that target nucleic acids cause neurotoxicity is not well described. We characterized the neurotoxicity of Hoechst 33342 (bis-benzimide), a common cell permeable nuclear dye, in primary neuronal cultures. The mechanism of cell death was not apoptotic, as death is rapid, not accompanied by typical nuclear morphological changes, and is insensitive to inhibitors of transcription, translation and caspase activity. In addition, free-radical scavenging agents failed to attenuate cell death, and damage was not accompanied by mitochondrial dysfunction. Neuronal processes of cells exposed to Hoechst 33342 display dramatic fragmentation prior to cell death. When this compound was applied selectively to the distal axons of sympathetic neurons grown in compartmented cultures, the distal axons were destroyed. However, the proximal processes present in the cell body compartment were spared, demonstrating direct axonal toxicity rather than a remote effect of nuclear dysfunction. Other cell-permeable nucleic acid binding dyes similarly caused rapid dendritic and axonal toxicity. The hypothesis that these nucleic acid binding dyes target RNA localized to dendrites and axons is supported by observations that RNase V1 induced similar, rapid neurite fragmentation. We conclude that the neurotoxic effects of nucleic acid binding compounds are mediated, at least in part, by direct neurite injury, which does not require involvement of the cell body and nucleus.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66220/1/j.1471-4159.2006.03653.x.pd

    The noise-lovers: cultures of speech and sound in second-century Rome

    Full text link
    This chapter provides an examination of an ideal of the ‘deliberate speaker’, who aims to reflect time, thought, and study in his speech. In the Roman Empire, words became a vital tool for creating and defending in-groups, and orators and authors in both Latin and Greek alleged, by contrast, that their enemies produced babbling noise rather than articulate speech. In this chapter, the ideal of the deliberate speaker is explored through the works of two very different contemporaries: the African-born Roman orator Fronto and the Syrian Christian apologist Tatian. Despite moving in very different circles, Fronto and Tatian both express their identity and authority through an expertise in words, in strikingly similar ways. The chapter ends with a call for scholars of the Roman Empire to create categories of analysis that move across different cultural and linguistic groups. If we do not, we risk merely replicating the parochialism and insularity of our sources.Accepted manuscrip

    Model-Based Learning of Local Image Features for Unsupervised Texture Segmentation

    No full text
    • …
    corecore