454 research outputs found

    MedGAN: Medical Image Translation using GANs

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    Image-to-image translation is considered a new frontier in the field of medical image analysis, with numerous potential applications. However, a large portion of recent approaches offers individualized solutions based on specialized task-specific architectures or require refinement through non-end-to-end training. In this paper, we propose a new framework, named MedGAN, for medical image-to-image translation which operates on the image level in an end-to-end manner. MedGAN builds upon recent advances in the field of generative adversarial networks (GANs) by merging the adversarial framework with a new combination of non-adversarial losses. We utilize a discriminator network as a trainable feature extractor which penalizes the discrepancy between the translated medical images and the desired modalities. Moreover, style-transfer losses are utilized to match the textures and fine-structures of the desired target images to the translated images. Additionally, we present a new generator architecture, titled CasNet, which enhances the sharpness of the translated medical outputs through progressive refinement via encoder-decoder pairs. Without any application-specific modifications, we apply MedGAN on three different tasks: PET-CT translation, correction of MR motion artefacts and PET image denoising. Perceptual analysis by radiologists and quantitative evaluations illustrate that the MedGAN outperforms other existing translation approaches.Comment: 16 pages, 8 figure

    Overview of Licensing Platforms based on Distributed Ledger Technology

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    The licensing of creative work is of broad and current interest. The European Commission proposes that when uploading a licensed digital work, the uploader should be checked by the system that one has the necessary rights. Technically this law is difficult to implement, as images with different intentions are shared, and even small changes like watermarks make it difficult to reveal similarities. The characteristics of distributed ledger technology could provide excellent support for the licensing and management of the rights of use. In this work, non-technical and technical criteria are defined to achieve an overview of the state-of-the-art solutions in the field of blockchain-based licensing platforms. Based on the criteria, different licensing platforms are reviewed, and the results are presented in a comparison matrix

    Finger Length Ratio (2D:4D) in Adults with Gender Identity Disorder

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    From early childhood, gender identity and the 2nd to 4th finger length ratio (2D:4D) are discriminative characteristics between sexes. Both the human brain and 2D:4D may be influenced by prenatal testosterone levels. This calls for an examination of 2D:4D in patients with gender identity disorder (GID) to study the possible influence of prenatal testosterone on gender identity. Until now, the only study carried out on this issue suggests lower prenatal testosterone levels in right-handed male-to-female GID patients (MtF). We compared 2D:4D of 56 GID patients (39MtF; 17 female-to-male GID patients, FtM) with data from a control sample of 176 men and 190 women. Bivariate group comparisons showed that right hand 2D:4D in MtF was significantly higher (feminized) than in male controls, but similar to female controls. The comparison of 2D:4D ratios of biological women revealed significantly higher (feminized) values for right hands of right handed FtM. Analysis of variance confirmed significant effects for sex and for gender identity on 2D:4D ratios but not for sexual orientation or for the interaction among variables. Our results indirectly point to the possibility of a weak influence of reduced prenatal testosterone as an etiological factor in the multifactorially influenced development of MtF GID. The development of FtM GID seems even more unlikely to be notably influenced by prenatal testosteron

    Electrocardiographic RR Interval Dynamic Analysis to Identify Acute Stroke Patients at High Risk for Atrial Fibrillation Episodes During Stroke Unit Admission

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    Patients at short-term risk of paroxysmal atrial fibrillation (PAF) often exhibit increased RR interval variability during sinus rhythm. We studied if RR dynamic analysis, applied in the first hours after stroke unit (SU) admission, identified acute ischemic stroke patients at higher risk for subsequent PAF episodes detected within the SU hospitalization. Acute ischemic stroke patients underwent continuous cardiac monitoring (CCM) using standard bedside monitors immediately after SU admission. The CCM tracks from the first 48\ua0h were analyzed using a telemedicine service (SRA clinic, Apoplex Medical, Germany). Based on the RR dynamics, the stroke risk analysis (SRA) algorithm stratified the risk for PAF as follows: low risk for PAF, high risk for PAF, presence of manifest AF. The subsequent presence/absence of PAF during the whole SU hospitalization was ruled out using all available CCMs, standard ECGs, or 24-h Holter ECGs. Two hundred patients (40% females, mean age 71\u2009\ub1\u200916\ua0years) were included. According to the initial SRA analysis, 111 patients (56%) were considered as low risk for PAF, 52 (26%) as high risk while 37 patients (18%) had manifest AF. A low-risk level SRA was associated with a reduced probability for subsequent PAF detection (1/111, 0.9%, 95% CI 0-4.3%) while a high-risk level SRA predicted an increased probability (20/52, 38.5% (95% CI 25-52%). RR dynamic analysis performed in the first hours after ischemic stroke may stratify patients into categories at low or high risk for forthcoming paroxysmal AF episodes detected within the SU hospitalization

    Advance Power Technology Experiment for the Starshine 3 Satellite

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    The Starshine 3 satellite will carry several power technology demonstrations. Since Starshine 3 is primarily a passive experiment and does not need electrical power to successfully complete its mission, the requirement for a highly reliable power system is greatly reduced. This creates an excellent opportunity to test new power technologies. Several government and commercial interests have teamed up to provide Starshine 3 with a small power system using state-of-the-art components. Starshine 3 will also fly novel integrated microelectronic power supplies (IMPS) for evaluation

    Probing for Sparse and Fast Variable Selection with Model-Based Boosting

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    We present a new variable selection method based on model-based gradient boosting and randomly permuted variables. Model-based boosting is a tool to fit a statistical model while performing variable selection at the same time. A drawback of the fitting lies in the need of multiple model fits on slightly altered data (e.g., cross-validation or bootstrap) to find the optimal number of boosting iterations and prevent overfitting. In our proposed approach, we augment the data set with randomly permuted versions of the true variables, so-called shadow variables, and stop the stepwise fitting as soon as such a variable would be added to the model. This allows variable selection in a single fit of the model without requiring further parameter tuning. We show that our probing approach can compete with state-of-the-art selection methods like stability selection in a high-dimensional classification benchmark and apply it on three gene expression data sets

    Toxicity Analysis in the ADEBAR Trial: Sequential Anthracycline-Taxane Therapy Compared with FEC120 for the Adjuvant Treatment of High-Risk Breast Cancer

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    Background: Data from meta-analyses have shown taxane-containing therapies to be superior to anthracycline-based treatments for high-risk breast cancer. Patients and Methods: The ADEBAR trial was a multicenter phase Ill trial in which patients with lymph node-positive breast cancer were prospectively randomized for either sequential anthracycline-taxane or FEC120 therapy. Patients received 4x epirubicin (90 mg/m(2)) and cyclophosphamide (600 mg/m(2)) every 3 weeks (q3w), followed by 4x docetaxel (100 mg/m(2)) q3w (EC-Doc arm), or 6x epirubicin (60 mg/m(2)) and 5-fluorouracil (500 mg/m(2)) on days 1 and 8 and cyclophosphamide (75 mg/m(2)) on days 1-14, q4w (FEC arm). We compared both arms with respect to toxicity and feasibility. Results: Hematological toxicity was found significantly more often in the FEC arm. Febrile neutropenia was seen in 11.3% of patients in the FEC arm and in 8.4% of patients in the EC-Doc arm (p = 0.027). Non-hematological side effects of grade 3/4 were rarely seen in either arm. Therapy was terminated due to toxicity in 3.7% of the patients in the EC-Doc arm and in 8.0% of the patients in the FEC arm (p = 0.0009). Conclusion: The sequential anthracycline-taxane regimen is a well-tolerated and feasible alternative to FEC120 therapy

    Derivation of the cubic NLS and Gross-Pitaevskii hierarchy from manybody dynamics in d=3d=3 based on spacetime norms

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    We derive the defocusing cubic Gross-Pitaevskii (GP) hierarchy in dimension d=3d=3, from an NN-body Schr\"{o}dinger equation describing a gas of interacting bosons in the GP scaling, in the limit NN\rightarrow\infty. The main result of this paper is the proof of convergence of the corresponding BBGKY hierarchy to a GP hierarchy in the spaces introduced in our previous work on the well-posedness of the Cauchy problem for GP hierarchies, \cite{chpa2,chpa3,chpa4}, which are inspired by the solutions spaces based on space-time norms introduced by Klainerman and Machedon in \cite{klma}. We note that in d=3d=3, this has been a well-known open problem in the field. While our results do not assume factorization of the solutions, consideration of factorized solutions yields a new derivation of the cubic, defocusing nonlinear Schr\"odinger equation (NLS) in d=3d=3.Comment: 44 pages, AMS Late
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