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The aggressiveness of prostate cancer, the most common cancer in men worldwide, is primarily assessed based on histopathological data using the Gleason scoring system. While artificial intelligence (AI) has shown promise in accurately predicting Gleason scores, these predictions often lack inherent explainability, potentially leading to distrust in human-machine interactions. To address this issue, we introduce a novel dataset of 1,015 tissue microarray core images, annotated by an international group of 54 pathologists. The annotations provide detailed localized pattern descriptions for Gleason grading in line with international guidelines. Utilizing this dataset, we develop an inherently explainable AI system based on a U-Net architecture that provides predictions leveraging pathologists' terminology. This approach circumvents post-hoc explainability methods while maintaining or exceeding the performance of methods trained directly for Gleason pattern segmentation (Dice score: 0.713 $\pm$ 0.003 trained on explanations vs. 0.691 $\pm$ 0.010 trained on Gleason patterns). By employing soft labels during training, we capture the intrinsic uncertainty in the data, yielding strong results in Gleason pattern segmentation even in the context of high interobserver variability. With the release of this dataset, we aim to encourage further research into segmentation in medical tasks with high levels of subjectivity and to advance the understanding of pathologists' reasoning processes., Comment: 58 pages, 15 figures (incl. supplementary)

Recording and analyzing infrasound signals is essential to study natural phenomena, such as earthquakes, weather, or avalanches, but also has practical importance in aviation industry, optimization of wind turbines, and many more. However, the detection of faint infrasound signals is still a significant challenge as the transducers (e.g., mechanical, optical, and piezoelectric) are either difficult to integrate or do not provide sufficient sensitivity. Here, we propose an alternative principle to detecting infrasound, which is based on a free-standing liquid film covered with a polymeric organic mixed ionic-electronic conductor (OMIEC). This polymer is capable of conducting ions, as well as electrons/holes and serves as a direct electronic infrasound transducer due to the sensitivity of OMIECs to the local ion concentration in the liquid. We specifically address the detection of acoustic excitations within the infrasound regime and the dependency of the networks reaction to these stimuli on its conductive properties, mainly its impedance spectrum. The resulting sensor has a sensitivity of 613 muV Pa-1 and a power consumption of about 340 nW at 100 mHz, which puts these systems well within the range of commercial infrasound detectors, while offering significant advantages in terms of device complexity and integration., Comment: 4 pages, 4 figures

Only 5% of what makes up the Universe is well understood, and it consists of baryonic matter and radiation. Dark matter and energy correspond to the remaining 95% of the Universe, and their origin and evolution have not yet been satisfactorily explained. Dark matter, supposedly present in the galaxies' halo region, appears to be the mechanism that causes the unusual behavior of the stars' tangential velocity, which is higher than that predicted by the interaction with visible matter. With the solutions of the equations of motion for spacetime generated by a spinning cosmic string with an internal structure in Brans-Dicke gravitation, the present work aimed to evaluate whether this type of string can play the role currently defined as that of dark matter, which is to originate the typical rotational curves of galaxies, responsible for maintaining the tangential velocities of the stars that form these galaxies, whose behavior cannot be justified solely by the observed baryonic matter. For this, the model was used to obtain the velocities of the stars of 4 Sc-type galaxies, to be compared with their respective experimentally observed values., Comment: 11 pages, 2 figures, text in Portuguese, work presented at the 23a. Mostra de Ensino, Pesquisa e Extens\~ao, IFRS, C\^ampus Porto Alegre, 2023

In the event of stroke, a catheter-guided procedure (thrombectomy) is used to remove blood clots. Feasibility of machine learning based automatic classifications for thrombus detection on digital substraction angiography (DSA) sequences has been demonstrated. It was however not used live in the clinic, yet. We present an open-source tool for automatic thrombus classification and test it on three selected clinical cases regarding functionality and classification runtime. With our trained model all large vessel occlusions in the M1 segment were correctly classified. One small remaining M3 thrombus was not detected. Runtime was in the range from 1 to 10 seconds depending on the used hardware. We conclude that our open-source software tool enables clinical staff to classify DSA sequences in (close to) realtime and can be used for further studies in clinics., Comment: This is the preprint version of the BVM paper accepted for publication in the conference proceedings of "Bildverarbeitung in der Medizin 2023"

Early adolescence is a time of major social change; a strong sense of belonging and peer connectedness is an essential protective factor in mental health during that period. In this paper we introduce LINA, an augmented reality (AR) smartphone-based serious game played in school by an entire class (age 10+) together with their teacher, which aims to facilitate and improve peer interaction, sense of belonging and class climate, while creating a safe space to reflect on mental health and external stressors related to family circumstance. LINA was developed through an interdisciplinary collaboration involving a playwright, software developers, psychologists, and artists, via an iterative co-development process with young people. A prototype has been evaluated quantitatively for usability and qualitatively for efficacy in a study with 91 early adolescents (agemean=11.41). Results from the Game User Experience Satisfaction Scale (GUESS-18) and data from qualitative focus groups showed high acceptability and preliminary efficacy of the game. Using AR, a shared immersive narrative and collaborative gameplay in a shared physical space offers an opportunity to harness adolescent affinity for digital technology towards improving real-world social connection and sense of belonging., Comment: 21 pages, 10 figures, 2 tables

Percutaneous thermal ablation is a minimally-invasive treatment option for renal cancer. To treat larger tumours, multiple overlapping ablations zones are required. Arrangements with a low number of ablation zones but coverage of the whole tumour volume are challenging to find for physicians. In this work, an open-source software tool with a new planning approach based on the automatic selection from a large number of randomized geometrical arrangements is presented. Two uncertainty parameters are introduced to account for tissue shrinking and tolerance of non-ablated tumour volume. For seven clinical renal T1a, T1b and T2a tumours, ablation plans were proposed by the software. All proposals are comparable to manual plans of an experienced physician with regard to the number of required ablation zones., Comment: Preprint version, accepted for publication in Bildverarbeitung f\"ur die Medizin (BVM) Proceedings 2020

Electromagnetic (EM) tracking enables localization of surgical instruments within the magnetic field emitted by an EM field generator (FG). Usually, the larger a FG is, the larger its tracking volume is. However, the company NDI (Northern Digital Inc., Waterloo, ON, Canada) recently introduced the Planar 10-11 FG, which combines a compact construction (97mm x 112mm x 31mm) with a relatively large, cylindrical tracking volume (diameter: 340mm, height: 340mm). Using the standardized assessment protocol of Hummel et al., the FG was tested with regard to its tracking accuracy and to its robustness with respect to external sources of disturbance. The mean positional error (5cm distance metric according to Hummel protocol) was 0.59mm, with a mean jitter of 0.26mm in the standard setup. The mean orientational error was found to be 0.10{\deg}. The highest positional error (4.82mm) due to metallic sources of disturbance was caused by the steel SST 303. In contrast, steel SST 416 caused the lowest positional error (0.10mm). Overall, the Planar 10-11 FG tends to achieve better tracking accuracy results compared to other NDI FGs. Due to its compact construction and portability, the FG could contribute to increased clinical use of EM tracking systems., Comment: This is the preprint version of the BVM paper already published in the conference proceedings of "Bildverarbeitung in der Medizin 2019". Paper written in German

Observation shows that the velocities of stars grow by approximately 2 to 3 orders of magnitude when the distances from the centers of the galaxies are in the range of $0.5$ kpc to $82.3$ kpc, before they begin to tend to a constant value. Up to know, the reason for this behavior is still a matter for debate. In this work, we propose a model which adequately describes this unusual behavior using a (nearly) cylindrical symmetrical solution in the framework of a scalar-tensor-like (the Brans-Dicke model) theory of gravity., Comment: 24 pages, 4 figures, accepted for publication in Eur. Phys. J. C

It is presented an exact solution of straight spinning cosmic strings in Brans-Dicke theory of gravitation. The possibility of the existence of closed timelike curves around these cosmic strings is analyzed. Furthermore, the stability about the formation of the topological defect discussed here is checked. It is shown the existence of a suitable choice for the integration constants in which closed timelike curves are not allowed. We also verify if it is possible that the obtained spacetime can be the source that describes the observed rotational curves in some galaxies., Comment: 13 pages, 1 figure

A set of multivariate polynomials, over a field of zero or large characteristic, can be tested for algebraic independence by the well-known Jacobian criterion. For fields of other characteristic p>0, there is no analogous characterization known. In this paper we give the first such criterion. Essentially, it boils down to a non-degeneracy condition on a lift of the Jacobian polynomial over (an unramified extension of) the ring of p-adic integers. Our proof builds on the de Rham-Witt complex, which was invented by Illusie (1979) for crystalline cohomology computations, and we deduce a natural generalization of the Jacobian. This new avatar we call the Witt-Jacobian. In essence, we show how to faithfully differentiate polynomials over F_p (i.e. somehow avoid dx^p/dx=0) and thus capture algebraic independence. We apply the new criterion to put the problem of testing algebraic independence in the complexity class NP^#P (previously best was PSPACE). Also, we give a modest application to the problem of identity testing in algebraic complexity theory.

Algebraic independence is an advanced notion in commutative algebra that generalizes independence of linear polynomials to higher degree. Polynomials {f_1, ..., f_m} \subset \F[x_1, ..., x_n] are called algebraically independent if there is no non-zero polynomial F such that F(f_1, ..., f_m) = 0. The transcendence degree, trdeg{f_1, ..., f_m}, is the maximal number r of algebraically independent polynomials in the set. In this paper we design blackbox and efficient linear maps \phi that reduce the number of variables from n to r but maintain trdeg{\phi(f_i)}_i = r, assuming f_i's sparse and small r. We apply these fundamental maps to solve several cases of blackbox identity testing: (1) Given a polynomial-degree circuit C and sparse polynomials f_1, ..., f_m with trdeg r, we can test blackbox D := C(f_1, ..., f_m) for zeroness in poly(size(D))^r time. (2) Define a spsp_\delta(k,s,n) circuit C to be of the form \sum_{i=1}^k \prod_{j=1}^s f_{i,j}, where f_{i,j} are sparse n-variate polynomials of degree at most \delta. For k = 2 we give a poly(sn\delta)^{\delta^2} time blackbox identity test. (3) For a general depth-4 circuit we define a notion of rank. Assuming there is a rank bound R for minimal simple spsp_\delta(k,s,n) identities, we give a poly(snR\delta)^{Rk\delta^2} time blackbox identity test for spsp_\delta(k,s,n) circuits. This partially generalizes the state of the art of depth-3 to depth-4 circuits. The notion of trdeg works best with large or zero characteristic, but we also give versions of our results for arbitrary fields., Comment: 32 pages, preliminary version