469 research outputs found

    Locally Adaptive Frames in the Roto-Translation Group and their Applications in Medical Imaging

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    Locally adaptive differential frames (gauge frames) are a well-known effective tool in image analysis, used in differential invariants and PDE-flows. However, at complex structures such as crossings or junctions, these frames are not well-defined. Therefore, we generalize the notion of gauge frames on images to gauge frames on data representations U:Rd⋊Sd−1→RU:\mathbb{R}^{d} \rtimes S^{d-1} \to \mathbb{R} defined on the extended space of positions and orientations, which we relate to data on the roto-translation group SE(d)SE(d), d=2,3d=2,3. This allows to define multiple frames per position, one per orientation. We compute these frames via exponential curve fits in the extended data representations in SE(d)SE(d). These curve fits minimize first or second order variational problems which are solved by spectral decomposition of, respectively, a structure tensor or Hessian of data on SE(d)SE(d). We include these gauge frames in differential invariants and crossing preserving PDE-flows acting on extended data representation UU and we show their advantage compared to the standard left-invariant frame on SE(d)SE(d). Applications include crossing-preserving filtering and improved segmentations of the vascular tree in retinal images, and new 3D extensions of coherence-enhancing diffusion via invertible orientation scores

    Measures to reduce fine dust emission from poultry houses: reduction from broiler houses by ionization

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    In this study the effect was determined of a commercially available air ionization system on the reduction of airborne dust in a broiler house. Results showed a reduction, based on particle mass, of 36% and 10% for PM10 and PM2.5, respectivel

    Vesselness via multiple scale orientation scores

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    The multi-scale Frangi vesselness filter is an established tool in (retinal) vascular imaging. However, it cannot cope with crossings or bifurcations, since it only looks for elongated structures. Therefore, we disentangle crossing structures in the image via (multiple scale) invertible orientation scores. The described vesselness filter via scale-orientation scores performs considerably better at enhancing vessels throughout crossings and bifurcations than the Frangi version. Both methods are evaluated on a public dataset. Performance is measured by comparing ground truth data to the segmentation results obtained by basic thresholding and morphological component analysis of the filtered images

    Lysine residue 121 in the proposed ATP-binding site of the v-mos protein is required for transformation.

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    Dihydro-CDDO-Trifluoroethyl Amide (dh404), a Novel Nrf2 Activator, Suppresses Oxidative Stress in Cardiomyocytes

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    Targeting Nrf2 signaling appears to be an attractive approach for the treatment of maladaptive cardiac remodeling and dysfunction; however, pharmacological modulation of the Nrf2 pathway in the cardiovascular system remains to be established. Herein, we report that a novel synthetic triterpenoid derivative, dihydro-CDDO-trifluoroethyl amide (dh404), activates Nrf2 and suppresses oxidative stress in cardiomyocytes. Dh404 interrupted the Keap1-Cul3-Rbx1 E3 ligase complex-mediated Nrf2 ubiquitination and subsequent degradation saturating the binding capacity of Keap1 to Nrf2, thereby rendering more Nrf2 to be translocated into the nuclei to activate Nrf2-driven gene transcription. A mutant Keap1 protein containing a single cysteine-to-serine substitution at residue 151 within the BTB domain of Keap1 was resistant to dh404-induced stabilization of Nrf2 protein. In addition, dh404 did not dissociate the interaction of Nrf2 with the Keap1-Cul3-Rbx1 E3 ligase complex. Thus, it is likely that dh404 inhibits the ability of Keap1-Cul3-Rbx1 E3 ligase complex to target Nrf2 for ubiquitination and degradation via modifying Cys-151 of Keap1 to change the conformation of the complex. Moreover, dh404 was able to stabilize Nrf2 protein, to enhance Nrf2 nuclear translocation, to activate Nrf2-driven transcription, and to suppress angiotensin II (Ang II)-induced oxidative stress in cardiomyocytes. Knockdown of Nrf2 almost blocked the anti-oxidative effect of dh404. Dh404 activated Nrf2 signaling in the heart. Taken together, dh404 appears to be a novel Nrf2 activator with a therapeutic potential for cardiac diseases via suppressing oxidative stress

    A healing journey with chronic pain – a meta-ethnography synthesising 195 qualitative studies

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    Objective There is a large body of research exploring what it means for a person to live with chronic pain. However, existing research does not help us understand what it means to recover. We aimed to identify qualitative research that explored the experience of living with chronic pain published since 2012 and to understand the process of recovery. Design A synthesis of qualitative research using meta-ethnography. Methods We used the seven stages of meta-ethnography. We systematically searched for qualitative research, published since 2012, that explored adults’ experiences of living with, and being treated for, chronic pain. We used constant comparison to distill the essence of ideas into themes and developed a conceptual model. Results We screened 1,328 titles and included 195 studies. Our conceptual model indicates that validation and reconnection can empower a person with chronic pain to embark on a journey of healing. To embark on this journey requires commitment, energy, and support. Conclusions The innovation of our study is to conceptualize healing as an ongoing and iterating journey rather than a destination. Health interventions for chronic pain would usefully focus on validating pain through meaningful and acceptable explanations; validating patients by listening to and valuing their stories; encouraging patients to connect with a meaningful sense of self, to be kind to themselves, and to explore new possibilities for the future; and facilitating safe reconnection with the social world. This could make a real difference to people living with chronic pain who are on their own healing journeys
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