Generating detailed saliency maps using model-agnostic methods

The emerging field of Explainable Artificial Intelligence focuses on researching methods of explaining the decision making processes of complex machine learning models. In the field of explainability for Computer Vision, explanations are provided as saliency maps, which visualize the importance of individual pixels of the input w.r.t. the model's prediction. In this work we focus on a perturbation-based, model-agnostic explainability method called RISE, elaborate on observed shortcomings of its grid-based approach and propose two modifications: replacement of square occlusions with convex polygonal occlusions based on cells of a Voronoi mesh and addition of an informativeness guarantee to the occlusion mask generator. These modifications, collectively called VRISE (Voronoi-RISE), are meant to, respectively, improve the accuracy of maps generated using large occlusions and accelerate convergence of saliency maps in cases where sampling density is either very low or very high. We perform a quantitative comparison of accuracy of saliency maps produced by VRISE and RISE on the validation split of ILSVRC2012, using a saliency-guided content insertion/deletion metric and a localization metric based on bounding boxes. Additionally, we explore the space of configurable occlusion pattern parameters to better understand their influence on saliency maps produced by RISE and VRISE. We also describe and demonstrate two effects observed over the course of experimentation, arising from the random sampling approach of RISE: "feature slicing" and "saliency misattribution". Our results show that convex polygonal occlusions yield more accurate maps for coarse occlusion meshes and multi-object images, but improvement is not guaranteed in other cases. The informativeness guarantee is shown to increase the convergence rate without incurring a significant computational overhead.Comment: 85 pages, 70 figures, Master's thesis, defended on 2021-12-23 (Gdansk University of Technology

Charge separation by photoexcitation in semicrystalline polymeric semiconductors: An intrinsic or extrinsic mechanism?

We probe charge photogeneration and subsequent recombination dynamics in neat regioregular poly(3-hexylthiophene) films over six decades in time by means of time-resolved photoluminescence spectroscopy. Exciton dissociation at 10K occurs extrinsically at interfaces between molecularly ordered and disordered domains. Polaron pairs thus produced recombine by tunnelling with distributed rates governed by the distribution of electron-hole radii. Quantum-chemical calculations suggest that hot-exciton dissociation at such interfaces results from a high charge-transfer character.Comment: 10 pages, 3 figure

Implementation of the Polish version of the 11th revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-11): importance for oncology

Member States of the World Health Organization (WHO), after several years of joint review, approved and implemented the update of the International Statistical Classification of Diseases and Related Health Problems (ICD) in May 2019. Usually, the abbreviated name ICD-11 (International Classification of Diseases, 11th Revision) is used. The new version was created in fully digital form with a search easy-to-use search engine available to every user. Many changes were introduced, and the most important is the redesign of the coding system to adapt it for digital use. ICD-11 codes are divided into main and supplementary codes. Main codes are at least 4 characters long, and 2 levels of extensions, up to 7 characters, are possible. In Poland, the entire process of implementing the ICD-11 is carried out as part of a project coordinated by the Medical Center for Postgraduate Education in cooperation with the Department of Healthcare of the Ministry of Health and the e-Health Centre. The implementation of the new version and the official introduction of ICD-11 in Poland must be preceded primarily by the amendment of legal acts (laws and regulations) and orders of the President of the National Health Fund, such as those regarding the reimbursement for refunded services and the keeping of medical records. An important element is the change in the cluster codes in oncology. Selected oncology groups were based on analyses of international reports on morbidity, mortality, cancer registries, and clinical reports. Cluster 02, which deals with cancer, contains 8 subsections detailing disease states associated with abnormal or uncontrolled cell proliferation. This article summarizes and discusses the most important changes in ICD-11, along with providing an introduction to the classification rules in the coding system and individual subsections on cancer

Field Effect Transistors for Terahertz Detection: Physics and First Imaging Applications

Resonant frequencies of the two-dimensional plasma in FETs increase with the reduction of the channel dimensions and can reach the THz range for sub-micron gate lengths. Nonlinear properties of the electron plasma in the transistor channel can be used for the detection and mixing of THz frequencies. At cryogenic temperatures resonant and gate voltage tunable detection related to plasma waves resonances, is observed. At room temperature, when plasma oscillations are overdamped, the FET can operate as an efficient broadband THz detector. We present the main theoretical and experimental results on THz detection by FETs in the context of their possible application for THz imaging.Comment: 22 pages, 12 figures, review pape

Molecular diagnostics of cancers – practical approach

Wprowadzenie do leczenia chorób nowotworowych terapii celowanych opartych na przeciwciałach monoklonalnych lub drobnocząsteczkowych inhibitorach kinaz doprowadziło, u wybranych chorych, do istotnej poprawy efektów leczenia. Uzyskanie wydłużenia czasu przeżycia bez progresji choroby czy przeżycia całkowitego wiąże się jednak z koniecznością wykonania na etapie diagnostyki szeregu oznaczeń molekularnych. Ich mnogość narzucana zapisami programów lekowych stwarza ogromne problemy we właściwym doborze poszczególnych oznaczeń oraz stanowi istotne wyzwanie w procesie rozliczenia wykonanych badań. W niniejszym opracowaniu podsumowano najważniejsze aspekty diagnostyki molekularnej nowotworów zalecanej i dostępnej w praktyce klinicznej w Polsce.Wprowadzenie do leczenia chorób nowotworowych terapii celowanych opartych na przeciwciałach monoklonalnych lub drobnocząsteczkowych inhibitorach kinaz doprowadziło, u wybranych chorych, do istotnej poprawy efektów leczenia. Uzyskanie wydłużenia czasu przeżycia bez progresji choroby czy przeżycia całkowitego wiąże się jednak z koniecznością wykonania na etapie diagnostyki szeregu oznaczeń molekularnych. Ich mnogość narzucana zapisami programów lekowych stwarza ogromne problemy we właściwym doborze poszczególnych oznaczeń oraz stanowi istotne wyzwanie w procesie rozliczenia wykonanych badań. W niniejszym opracowaniu podsumowano najważniejsze aspekty diagnostyki molekularnej nowotworów zalecanej i dostępnej w praktyce klinicznej w Polsce

Diagnostyka molekularna nowotworów – podejście praktyczne

Wprowadzenie do leczenia chorób nowotworowych terapii celowanych opartych na przeciwciałach monoklonalnych lub drobnocząsteczkowych inhibitorach kinaz doprowadziło, u wybranych chorych, do istotnej poprawy efektów leczenia. Uzyskanie wydłużenia czasu przeżycia bez progresji choroby czy przeżycia całkowitego wiąże się jednak z koniecznością wykonania na etapie diagnostyki szeregu oznaczeń molekularnych. Ich mnogość narzucana zapisami programów lekowych stwarza ogromne problemy we właściwym doborze poszczególnych oznaczeń oraz stanowi istotne wyzwanie w procesie rozliczenia wykonanych badań. W niniejszym opracowaniu podsumowano najważniejsze aspekty diagnostyki molekularnej nowotworów zalecanej i dostępnej w praktyce klinicznej w Polsce.Wprowadzenie terapii celowanych opartych na przeciwciałach monoklonalnych lub drobnocząsteczkowych inhibitorach kinaz do leczenia chorob nowotworowych doprowadziło do istotnej poprawy wynikow leczenia wybranych chorych. Wydłużenie czasu przeżycia bez progresji choroby czy przeżycia całkowitego wiąże się jednak z koniecznością wykonania na etapie diagnostyki szeregu oznaczeń molekularnych. Ich mnogość – narzucana zapisami programow lekowych – stwarza ogromne problemy we właściwym doborze poszczegolnych oznaczeń oraz stanowi istotne wyzwanie w procesie rozliczania wykonanych badań. W tym opracowaniu podsumowano najważniejsze aspekty diagnostyki molekularnej nowotworow zalecanej i dostępnej w praktyce klinicznej w Polsce

Diagnostic Usefulness of Spiroergometry and Risk Factors of Long COVID in Patients with Normal Left Ventricular Ejection Fraction

The emergence of the Coronavirus Disease 2019 (COVID-19) pandemic has brought forth various clinical manifestations and long-term complications, including a condition known as long COVID. Long COVID refers to a persistent set of symptoms that continue beyond the acute phase of the disease. This study investigated the risk factors and the utility of spiroergometry parameters for diagnosing patients with long COVID symptoms. The 146 patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection with normal left ventricular ejection fraction and without respiratory diseases were included and divided into two groups: the group demonstrating long COVID symptoms [n = 44] and the group without long COVID symptoms [n = 102]. The clinical examinations, laboratory test results, echocardiography, non-invasive body mass analysis, and spiroergometry were evaluated. ClinicalTrials.gov Identifier: NCT04828629. Patients with long COVID symptoms had significantly higher age [58 (vs.) 44 years; p p = 0.02)], left atrial diameter (LA) [37 vs. 35 mm; p = 0.04], left ventricular mass index (LVMI) [83 vs. 74 g/m2, p = 0.04], left diastolic filling velocity (A) [69 vs. 64 cm/s, p = 0.01], the ratio of peak velocity of early diastolic transmitral flow to peak velocity of early diastolic mitral annular motion (E/E’) [7.35 vs. 6.05; p = 0.01], and a lower ratio of early to late diastolic transmitral flow velocity (E/A) [1.05 vs. 1.31; p = 0.01] compared to the control group. In cardiopulmonary exercise testing (CPET), long COVID patients presented lower forced vital capacity (FVC) [3.6 vs. 4.3 L; p 2max) [21 vs. 23 mL/min/kg; p = 0.04], respiratory exchange ratio (RER) [1.0 vs. 1.1; p = 0.04], forced expiratory volume in one second (FEV1) [2.90 vs. 3.25 L; p = 0.04], and a higher ratio of forced expiratory volume in one second to forced vital capacity (FEV1/FVC%) [106 vs. 100%; p = 0.0002]. The laboratory results pointed out that patients with long COVID symptoms also had a lower rate of red blood cells (RBC) [4.4 vs. 4.6 × 106/uL; p = 0.01]; a higher level of glucose [92 vs. 90 mg/dL; p = 0.03]; a lower glomerular filtration rate (GFR) estimate by Modification of Diet in Renal Disease (MDRD) [88 vs. 95; p = 0.03]; and a higher level of hypersensitive cardiac Troponin T (hs-cTnT) [6.1 vs. 3.9 pg/mL; p = 0.04]. On the multivariate model, only FEV1/FVC% (OR 6.27, 95% CI: 2.64–14.86; p p < 0.001) in predicting the symptoms of long COVID. Spiroergometry parameters are useful in diagnosing long COVID and differentiating it from cardiovascular disease