Linking Cellular and Mechanical Processes in Articular Cartilage Lesion Formation: A Mathematical Model

A severe application of stress on articular cartilage can initiate a cascade of biochemical reactions that can lead to the development of osteoarthritis. We constructed a multiscale mathematical model of the process with three components: cellular, chemical, and mechanical. The cellular component describes the different chondrocyte states according to the chemicals these cells release. The chemical component models the change in concentrations of those chemicals. The mechanical component contains a simulation of pressure application onto a cartilage explant and the resulting strains that initiate the biochemical processes. The model creates a framework for incorporating explicit mechanics, simulated by finite element analysis, into a theoretical biology framework

EasyPortrait - Face Parsing and Portrait Segmentation Dataset

Recently, due to COVID-19 and the growing demand for remote work, video conferencing apps have become especially widespread. The most valuable features of video chats are real-time background removal and face beautification. While solving these tasks, computer vision researchers face the problem of having relevant data for the training stage. There is no large dataset with high-quality labeled and diverse images of people in front of a laptop or smartphone camera to train a lightweight model without additional approaches. To boost the progress in this area, we provide a new image dataset, EasyPortrait, for portrait segmentation and face parsing tasks. It contains 20,000 primarily indoor photos of 8,377 unique users, and fine-grained segmentation masks separated into 9 classes. Images are collected and labeled from crowdsourcing platforms. Unlike most face parsing datasets, in EasyPortrait, the beard is not considered part of the skin mask, and the inside area of the mouth is separated from the teeth. These features allow using EasyPortrait for skin enhancement and teeth whitening tasks. This paper describes the pipeline for creating a large-scale and clean image segmentation dataset using crowdsourcing platforms without additional synthetic data. Moreover, we trained several models on EasyPortrait and showed experimental results. Proposed dataset and trained models are publicly available.Comment: portrait segmentation, face parsing, image segmentation datase

Slovo: Russian Sign Language Dataset

One of the main challenges of the sign language recognition task is the difficulty of collecting a suitable dataset due to the gap between hard-of-hearing and hearing societies. In addition, the sign language in each country differs significantly, which obliges the creation of new data for each of them. This paper presents the Russian Sign Language (RSL) video dataset Slovo, produced using crowdsourcing platforms. The dataset contains 20,000 FullHD recordings, divided into 1,000 classes of isolated RSL gestures received by 194 signers. We also provide the entire dataset creation pipeline, from data collection to video annotation, with the following demo application. Several neural networks are trained and evaluated on the Slovo to demonstrate its teaching ability. Proposed data and pre-trained models are publicly available.Comment: russian sign language recognition dataset, open-source, 11 page

A Mathematical Model of Cancer Stem Cell Lineage Population Dynamics with Mutation Accumulation and Telomere Length Hierarchies

There is evidence that cancer develops when cells acquire a sequence of mutations that alter normal cell characteristics. This sequence determines a hierarchy among the cells, based on how many more mutations they need to accumulate in order to become cancerous. When cells divide, they exhibit telomere loss and differentiate, which defines another cell hierarchy, on top of which is the stem cell. We propose a mutation-generation model, which combines the mutation-accumulation hierarchy with the differentiation hierarchy of the cells, allowing us to take a step further in examining cancer development and growth. The results of the model support the hypothesis of the cancer stem cell’s role in cancer pathogenesis: a very small fraction of the cancer cell population is responsible for the cancer growth and development. Also, according to the model, the nature of mutation accumulation is sufficient to explain the faster growth of the cancer cell population. However, numerical results show that in order for a cancer to develop within a reasonable time frame, cancer cells need to exhibit a higher proliferation rate than normal cells

Management of costs for the quality of insurance services

У каждой компании существует статья расходов на страхование, и абсолютно каждая компания, имея статьи расходов, стремится максимально их оптимизировать и сократить свои затраты. Порой такие оптимизации особенно в части страхования приводят к очень плачевным последствиям в части финансовых потерь, связанных с невыплатой страхового возмещения страховщиком. Такие ситуации происходят, как правило, из-за погони менеджеров компании максимально сократить расходы на страховую защиту, при этом значительно снизив ее качество.Each company has an item of insurance costs, and absolutely every company, having items of expenditure, seeks to optimize them as much as possible and reduce their costs. Sometimes such optimizations, especially in terms of insurance, lead to very disastrous consequences in terms of financial losses associated with nonpayment of insurance compensation by the insurer. Such situations occur, as a rule, because of the pursuit of managers of the company to minimize the cost of insurance coverage for the sake of its quality or simply because of ignorance of managers of price policy in the insurance of various types of property and choosing the cheapest options, which in most cases leads to the choice of less quality services

Calculation of Traffic Capacity of Signaled Intersections

In order to calculate traffic capacity of signaled intersections, it was suggested to apply an approach based on the concept of congestions. The paper states examples of traffic capacity calculation

Spatial distribution of atmospheric methane over Lake Baikal surface

Methane is the most important of organic substance in the atmosphere, and its concentration significantly exceeds the concentration of other organic compounds. The contribution from methane to the greenhouse effect is about 30 % of that from carbon dioxide. On the global scale, natural sources of methane are wetlands, rice fields, cattle, biomass burning, as well as gas-hydrates.The discovery of natural methane gas-hydrates sparked the increased interest in gashydrates and was followed by a series of investigations, by which enormous fuel reserves were discovered in the form of gas-hydrates stored in the bottom of the world ocean. Gas-hydrates attract a lot of scientific attention, not only because they can be used as fuel and chemical raw material, but also in the context of possible emissions of the methane into the atmosphere. Gas-hydrate crystals in Lake Baikal have been found quite recently. Lake Baikal is a convenient object for the investigation of gas hydrates and of gas vents at the lake floor. The aim of this work was to find anomalies in the methane distribution in the atmosphere over Lake Baikal surface using a high-sensitivity laser methane detector.The methane detector employs a GaInPAs diode laser as a source of radiation. The diode laser operates in the range from 6000 to 6080 cm-1 (1.645-1.666 µm), which includes rather strong absorption lines of methane. The detector was calibrated by a nitrogen-methane mixture with a methane concentration of 2.0 ppm. The detection limit (standard deviation) was 0.037 ppm, and time constant of the methane detector on the whole (with the allowance for the pump productivity and cell volume) was 99 s (spatial resolution of 450 m).The measurements of the methane content in the atmosphere over Lake Baikal were conducted by means of continuous air sampling from a height of 2-10 m above the water level from aboard R/V Vereshchagin in the periods of 10-16 August 2003 and of 16-24 June 2004. The coordinates of the measurement points were determined by the shipboard GPS system.Analysis of the data obtained in the course of the August 2003 expedition has shown that the methane concentration in near-surface air all along Lake Baikal averaged 2.001(0.16) ppm ; the standard deviation did not exceed 0.2 ppm. A distinctive and considerable (5.5 ppm) anomaly was observed near a shallow-water seep near the Selenga River inflow. Methane concentration distribution in near-surface air along the vessel’s track of 15 August 2003 showed a sharp peak that was limited in space and time.The average methane concentration in near-surface air over the South and Central Baikal Basins during the June 2004 expedition was 1.91(0.07) ppm and distinctive and considerable (more than 2.4 ppm) anomalies were observed at six areas in the Central Baikal Basin. Methane concentration distribution in near-surface air along the vessel’s tracks of 16-24 June 2004 was similar to the one obtained in 2003, with sharp peaks that were limited in space and time. Maximum air methane concentration (30 ppm) was detected near the Selenga shallow-water seep. In contrast to data obtained in August 2003 in the areas of visible methane escapes (Selenga River inflow and Babushkin village) groups of closely set methane escapes were observed. The distinctive and considerable (4 ppm) peak of the near-surface air methane concentration was observed near Mishicha, at a water depth of about 1000 m.The direct measurements of methane fluxes are very important for assessment of global fluxes of methane from water surface to the atmosphere. These measurements were carried out on vessel board for the first time. The most intensive fluxes (maximum methane flux was 2.12 E-9 kg/s m2) were observed near Babushkin village, where also maximum values of methane concentrations in near-surface water were detected. The typical magnitude of methane flux in most areas was within the limits of 1-3 E-12 kg/s m2. We also observed small inverse metha

Multifrequency dial sensing of the atmospheric gaseous constituents using the first and second harmonics of a tunable CO2 laser radiation

The results of field measurements of concentration of some gaseous components of the atmosphere along the paths, in Sofia, Bulgaria, using a gas analyzer based on the use of a CO2 laser radiation frequency-doubled with ZnGeP2 monocrystals are presented. The gas analyzer is a traditional long path absorption meter. Radiation from the tunable CO2 laser of low pressure and from an additional He-Ne laser is directed to a colliminating hundredfold Gregori telescope with a 300 mm diameter of the principal mirror. The dimensions of the mirrors of a retroreflector 500 x 500 mm and a receiving telescope allow one to totally intercept the beam passed through the atmospheric layer under study and back