175 research outputs found

    Distortion Estimation in Compressed Music Using Only Audio Fingerprints

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    Effects of grazing management on biodiversity across trophic levels–The importance of livestock species and stocking density in salt marshes

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    European coastal salt marshes are important for the conservation of numerous species of specialist plants, invertebrates, breeding and migratory birds. When these marshes are managed for nature conservation purposes, livestock grazing is often used to counter the dominance of the tall grass Elytrigia atherica, and the subsequent decline in plant species richness. However, it remains unclear what is the optimal choice of livestock species and stocking density to benefit biodiversity of various trophic levels. To fill this knowledge gap, we set up a triplicate, full factorial grazing experiment with cattle and horse grazing at low and high stocking densities (0.5 or 1 animal ha−1) at the mainland coast of the Dutch Wadden Sea. Here, we present the results after 4 years and integrate these with previously published results from the same experiment to assess effects of livestock grazing on various trophic groups. Stocking density affected almost all measured variables: high stocking densities favoured plant species richness and suppression of E. atherica, whereas low stocking densities favoured abundances of voles, pollinators and flowers. Densities of different functional groups of birds showed no significant response to the regimes, but tended to be somewhat higher under 0.5 horse and 1 cattle ha−1. Choice of livestock species had fewer and smaller effects than stocking density. Horse grazing was detrimental to vole density, and showed an interactive effect with stocking density for Asteraceae flower abundance. Multidiversity, a synthetic whole-ecosystem biodiversity measure, did not differ among regimes. These results are discussed in the light of other results from the same experiment. Because of these contrasting effects on different trophic groups, we advise concurrent application of different grazing regimes within a spatial mosaic, with the inclusion of long-term abandonment. High density horse grazing, however, is detrimental to biodiversity

    Brain and Head-and-Neck MRI in Immobilization Mask: A Practical Solution for MR-Only Radiotherapy

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    In brain/head-and-neck radiotherapy (RT), thermoplastic immobilization masks guarantee reproducible patient positioning in treatment position between MRI, CT, and irradiation. Since immobilization masks do not fit in the diagnostic MR head/head-and-neck coils, flexible surface coils are used for MRI imaging in clinical practice. These coils are placed around the head/neck, in contact with the immobilization masks. However, the positioning of these flexible coils is technician dependent, thus leading to poor image reproducibility. Additionally, flexible surface coils have an inferior signal-to-noise-ratio (SNR) compared to diagnostic coils. The aim of this work was to create a new immobilization setup which fits into the diagnostic MR coils in order to enhance MR image quality and reproducibility. For this purpose, a practical immobilization setup was constructed. The performances of the standard clinical and the proposed setups were compared with four tests: SNR, image quality, motion restriction, and reproducibility of inter-fraction subject positioning. The new immobilization setup resulted in 3.4 times higher SNR values on average than the standard setup, except directly below the flexible surface coils where similar SNR was observed. Overall, the image quality was superior for brain/head-and-neck images acquired with the proposed RT setup. Comparable motion restriction in feet-head/left-right directions (maximum motion ≈1 mm) and comparable inter-fraction repositioning accuracy (mean inter-fraction movement 1 ± 0.5 mm) were observed for the standard and the new setup

    Supine MRI for regional breast radiotherapy: Imaging axillary lymph nodes before and after sentinel-node biopsy

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    Regional radiotherapy (RT) is increasingly used in breast cancer treatment. Conventionally, computed tomography (CT) is performed for RT planning. Lymph node (LN) target levels are delineated according to anatomical boundaries. Magnetic resonance imaging (MRI) could enable individual LN delineation. The purpose was to evaluate the applicability of MRI for LN detection in supine treatment position, before and after sentinel-node biopsy (SNB). Twenty-three female breast cancer patients (cTis-3N0M0) underwent 1.5 T MRI, before and after SNB, in addition to CT. Endurance for MRI was monitored. Axillary levels were delineated. LNs were identified and delineated on MRI from before and after SNB, and on CT, and compared by Wilcoxon signed-rank tests. LN locations and LN-based volumes were related to axillary delineations and associated volumes. Although postoperative effects were visible, LN numbers on postoperative MRI (median 26 LNs) were highly reproducible compared to preoperative MRI when adding excised sentinel nodes, and higher than on CT (median 11, p < 0.001). LN-based volumes were considerably smaller than respective axillary levels. Supine MRI of LNs is feasible and reproducible before and after SNB. This may lead to more accurate RT target definition compared to CT, with potentially lower toxicity. With the MRI techniques described here, initiation of novel MRI-guided RT strategies aiming at individual LNs could be possible

    Deep learning-based image reconstruction and motion estimation from undersampled radial k-space for real-time MRI-guided radiotherapy.

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    To enable magnetic resonance imaging (MRI)-guided radiotherapy with real-time adaptation, motion must be quickly estimated with low latency. The motion estimate is used to adapt the radiation beam to the current anatomy, yielding a more conformal dose distribution. As the MR acquisition is the largest component of latency, deep learning (DL) may reduce the total latency by enabling much higher undersampling factors compared to conventional reconstruction and motion estimation methods. The benefit of DL on image reconstruction and motion estimation was investigated for obtaining accurate deformation vector fields (DVFs) with high temporal resolution and minimal latency. 2D cine MRI acquired at 1.5 T from 135 abdominal cancer patients were retrospectively included in this study. Undersampled radial golden angle acquisitions were retrospectively simulated. DVFs were computed using different combinations of conventional- and DL-based methods for image reconstruction and motion estimation, allowing a comparison of four approaches to achieve real-time motion estimation. The four approaches were evaluated based on the end-point-error and root-mean-square error compared to a ground-truth optical flow estimate on fully-sampled images, the structural similarity (SSIM) after registration and time necessary to acquire k-space, reconstruct an image and estimate motion. The lowest DVF error and highest SSIM were obtained using conventional methods up to [Formula: see text]. For undersampling factors [Formula: see text], the lowest DVF error and highest SSIM were obtained using conventional image reconstruction and DL-based motion estimation. We have found that, with this combination, accurate DVFs can be obtained up to [Formula: see text] with an average root-mean-square error up to 1 millimeter and an SSIM greater than 0.8 after registration, taking 60 milliseconds. High-quality 2D DVFs from highly undersampled k-space can be obtained with a high temporal resolution with conventional image reconstruction and a deep learning-based motion estimation approach for real-time adaptive MRI-guided radiotherapy

    Patient-Reported Outcome Measures May Add Value in Breast Cancer Surgery

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    Purpose: Considering the comparable prognosis in early-stage breast cancer after breast-conserving therapy (BCT) and mastectomy, quality of life should be a focus in treatment decision(s). We retrospectively collected PROs and analyzed differences per type of surgery delivered. We aimed to obtain reference values helpful in shared decision-making. Patients and Methods: pTis-T3N0-3M0 patients operated between January 2005 and September 2016 were eligible if: (1) no chemotherapy was administered < 6 months prior to enrolment, and (2) identical surgeries were performed in case of bilateral surgery. After consent, EQ-5D-5L, EORTC-QLQ-C30/BR23, and BREAST-Q were administered. PROs were evaluated per baseline characteristics using multivariable linear regression models. Outcomes were compared for different surgeries as well as for primary (PBC) and second primary or recurrent (SBC) breast cancer patients using analyses of variance (ANOVAs). Results: The response rate was 68%. PROs in 612 PBC patients were comparable to those in 152 SBC patients. Multivariable analyses showed increasing age to be associated with lower “physical functioning” [β − 0.259, p < 0.001] and “sexual functioning” [β − 0.427, p < 0.001], and increasing time since surgery with less “fatigue” [β − 1.083, p < 0.001]. Mastectomy [β − 13.596, p = 0.003] and implant reconstruction [β − 13.040, p = 0.007] were associated with lower “satisfaction with breast” scores than BCT. Radiation therapy was associated with lower satisfaction scores than absence of radiotherapy. Discussion: PRO scores were associated with age, time since surgery, type of surgery, and radiation therapy in breast cancer patients. The scores serve as a reference value for different types of surgery in the study population and enable prospective use of PROs in shared decision-making

    Travels among Europe's Muslim Neighbours - The Quest for Democracy. CEPS Paperbacks. May 2008

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    In Travels among Europe’s Muslim Neighbours – The Quest for Democracy, two Dutch Members of the European Parliament, Joost Lagendijk and Jan Marinus Wiersma, report on their talks with leading politicians of democratic and moderate Islamist convictions in the Balkans, Turkey, Egypt and Morocco. Their accounts have a vivid quality that gives the reader the sense of having been part of their missions. The underlying theme is the search for ways in which Europe’s Muslim neighbourhood might eventually become more democratic, rather than remain – at least in the case of the Arab Mediterranean states – ruled by largely authoritarian regimes. The role of democratic Turkey as an important reference throughout the region is highlighted. The authors also argue the case for EU policy to engage in dialogue with all democratic parties in the region, including in particular the Muslim democrats, which is not the case at the moment. The book complements two other related works recently published by CEPS: European Islam – Challenges for Society and Public Policy and Political Islam and European Foreign Policy
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