73 research outputs found
Protocol for robust and efficient preparation of the self-blotting nanowire TEM grids
Functional sample comprises a protocol for preparation of the TEM grids coated with the Cu(OH)2 nanowires. Such TEM grids are specifically suitable for preparation of the macromolecular samples for cryo-electron microscopy using spray of piezo-dispenzing devices.FunkÄŤnĂ vzorek poskytuje protokol pro pĹ™Ăpravu TEM mĹ™ĂĹľek potaĹľenĂ˝ch vrstvou Cu(OH)2 nanovláken. TakovĂ© TEM mĹ™ĂĹľky jsou specificky vhodnĂ© pro pĹ™Ăpravu komplexĹŻ makromolekul pro účely kryo-elektronovĂ© mikroskopie pomocĂ sprejovacĂho zaĹ™ĂzenĂ.Functional sample comprises a protocol for preparation of the TEM grids coated with the Cu(OH)2 nanowires. Such TEM grids are specifically suitable for preparation of the macromolecular samples for cryo-electron microscopy using spray of piezo-dispenzing devices
Unsupervised extraction, labelling and clustering of segments from clinical notes
This work is motivated by the scarcity of tools for accurate, unsupervised
information extraction from unstructured clinical notes in computationally
underrepresented languages, such as Czech. We introduce a stepping stone to a
broad array of downstream tasks such as summarisation or integration of
individual patient records, extraction of structured information for national
cancer registry reporting or building of semi-structured semantic patient
representations for computing patient embeddings. More specifically, we present
a method for unsupervised extraction of semantically-labelled textual segments
from clinical notes and test it out on a dataset of Czech breast cancer
patients, provided by Masaryk Memorial Cancer Institute (the largest Czech
hospital specialising in oncology). Our goal was to extract, classify (i.e.
label) and cluster segments of the free-text notes that correspond to specific
clinical features (e.g., family background, comorbidities or toxicities). The
presented results demonstrate the practical relevance of the proposed approach
for building more sophisticated extraction and analytical pipelines deployed on
Czech clinical notes.Comment: To be published at the IEEE BIBM 2022 conferenc
Biological Applications of Knowledge Graph Embedding Models
Complex biological systems are traditionally modelled as graphs of interconnected biological entities. These graphs, i.e. biological knowledge graphs, are then processed using graph exploratory approaches to perform different types of analytical and predictive tasks. Despite the high predictive accuracy of these approaches, they have limited scalability due to their dependency on time-consuming path exploratory procedures. In recent years, owing to the rapid advances of computational technologies, new approaches for modelling graphs and mining them with high accuracy and scalability have emerged. These approaches, i.e. knowledge graph embedding (KGE) models, operate by learning low-rank vector representations of graph nodes and edges that preserve the graph s inherent structure. These approaches were used to analyse knowledge graphs from different domains where they showed superior performance and accuracy compared to previous graph exploratory approaches. In this work, we study this class of models in the context of biological knowledge graphs and their different applications. We then show how KGE models can be a natural fit for representing complex biological knowledge modelled as graphs. We also discuss their predictive and analytical capabilities in different biology applications. In this regard, we present two example case studies that demonstrate the capabilities of KGE models: prediction of drug target interactions and polypharmacy side effects. Finally, we analyse different practical considerations for KGEs, and we discuss possible opportunities and challenges related to adopting them for modelling biological systems.The work presented in this paper was supported by the CLARIFY project that has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 875160, and by Insight research centre supported by the Science Foundation Ireland (SFI) grant (12/RC/2289_2)peer-reviewed2021-02-1
On scaling of human body models
Abstract
Human body is not an unique being, everyone is another from the point of view of anthropometry and mechanical
characteristics which means that division of the human body population to categories like 5%-tile, 50%-tile
and 95%-tile from the application point of view is not enough. On the other hand, the development of a particular
human body model for all of us is not possible. That is why scaling and morphing algorithms has started to be
developed. The current work describes the development of a tool for scaling of the human models. The idea is to
have one (or couple of) standard model(s) as a base and to create other models based on these basic models. One
has to choose adequate anthropometrical and biomechanical parameters that describe given group of humans to be
scaled and morphed among
Boundary heat diffusion classifier for a semi-supervised learning in a multilayer network embedding
International audienceThe scarcity of high-quality annotations in many application scenarios has recently led to an increasing interest in devising learning techniques that combine unlabeled data with labeled data in a network. In this work, we focus on the label propagation problem in multilayer networks. Our approach is inspired by the heat diffusion model, which shows usefulness in machine learning problems such as classification and dimensionality reduction. We propose a novel boundary-based heat diffusion algorithm that guarantees a closed-form solution with an efficient implementation. We experimentally validated our method on synthetic networks and five real-world multilayer network datasets representing scientific coauthorship, spreading drug adoption among physicians, two bibliographic networks, and a movie network. The results demonstrate the benefits of the proposed algorithm, where our boundary-based heat diffusion dominates the performance of the state-of-the-art methods
On Predicting Recurrence in Early Stage Non-small Cell Lung Cancer
Early detection and mitigation of disease recurrence in non-small cell lung cancer (NSCLC) patients is a nontrivial problem that is typically addressed either by rather generic follow-up screening guidelines, self-reporting, simple nomograms, or by models that predict relapse risk in individual patients using statistical analysis of retrospective data. We posit that machine learning models trained on patient data can provide an alternative approach that allows for more efficient development of many complementary models at once, superior accuracy, less dependency on the data collection protocols and increased support for explainability of the predictions. In this preliminary study, we describe an experimental suite of various machine learning models applied on a patient cohort of 2442 early stage NSCLC patients. We discuss the promising results achieved, as well as the lessons we learned while developing this baseline for further, more advanced studies in this area
Accurate prediction of kinase-substrate networks using knowledge graphs
Phosphorylation of specific substrates by protein kinases is a key control mechanism for vital cell-fate decisions and other cellular processes. However, discovering specific kinase-substrate relationships is time-consuming and often rather serendipitous. Computational predictions alleviate these challenges, but the current approaches suffer from limitations like restricted kinome coverage and inaccuracy. They also typically utilise only local features without reflecting broader interaction context. To address these limitations, we have developed an alternative predictive model. It uses statistical relational learning on top of phosphorylation networks interpreted as knowledge graphs, a simple yet robust model for representing networked knowledge. Compared to a representative selection of six existing systems, our model has the highest kinome coverage and produces biologically valid high-confidence predictions not possible with the other tools. Specifically, we have experimentally validated predictions of previously unknown phosphorylations by the LATS1, AKT1, PKA and MST2 kinases in human. Thus, our tool is useful for focusing phosphoproteomic experiments, and facilitates the discovery of new phosphorylation reactions. Our model can be accessed publicly via an easy-to-use web interface (LinkPhinder).Phosphorylation of specific substrates by protein kinases is a key control mechanism for vital cell-fate decisions and other cellular processes. However, discovering specific kinase-substrate relationships is time-consuming and often rather serendipitous. Computational predictions alleviate these challenges, but the current approaches suffer from limitations like restricted kinome coverage and inaccuracy. They also typically utilise only local features without reflecting broader interaction context. To address these limitations, we have developed an alternative predictive model. It uses statistical relational learning on top of phosphorylation networks interpreted as knowledge graphs, a simple yet robust model for representing networked knowledge. Compared to a representative selection of six existing systems, our model has the highest kinome coverage and produces biologically valid high-confidence predictions not possible with the other tools. Specifically, we have experimentally validated predictions of previously unknown phosphorylations by the LATS1, AKT1, PKA and MST2 kinases in human. Thus, our tool is useful for focusing phosphoproteomic experiments, and facilitates the discovery of new phosphorylation reactions. Our model can be accessed publicly via an easy-to-use web interface (LinkPhinder)
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