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The article presents a vision system for detecting elements of railway track. Four types of fasteners, wooden and concrete sleepers, rails, and turnouts can be recognized by our system. In addition, it is possible to determine the degree of sleeper ballast coverage. Our system is also able to work when the track is moderately covered by snow. We used a Fully Convolutional Neural Network with 8 times upsampling (FCN-8) to detect railway track elements. In order to speed up training and improve performance of the model, a pre-trained deep convolutional neural network developed by Oxford’s Visual Geometry Group (VGG16) was used as a framework for our system. We also verified the invariance of our system to changes in brightness. To do this, we artificially varied the brightness of images. We performed two types of tests. In the first test, we changed the brightness by a constant value for the whole analyzed image. In the second test, we changed the brightness according to a predefined distribution corresponding to Gaussian function.

A particularly important activity carried out by railway infrastructure managers to maintain railway devices in full working order is the diagnostic process. It increases the level of railway safety. The diagnostic process involves collecting information about the equipment through inspections, tests, functional trials, parameter measurements, and analysis of the working environment, followed by comparing the obtained information with the required parameters or permissible conditions. This activity also enables the formulation of a technical diagnosis regarding the current ability of the devices to perform its intended functions, taking into account the impact of its technical condition on railway traffic safety. This is especially important in the case of railway traffic control devices, as these devices are largely responsible for ensuring railway traffic safety. The collection of data on the condition of railway traffic control devices in the form of Big Data sets and diagnostic inference is an effective factor in making operational decisions for such devices. It enables the acquisition of complete information about the actual course of the exploitation process and allows for obtaining reliable information necessary to manage this process, particularly in the areas of diagnostics forecasting of devices conditions, renewal, and organization of maintenance and repair facilities. To support this, a service data acquisition and analysis system for railway traffic control devices (SADEK) was developed. This system can serve as a software platform for maintenance needs in the railway sector.

The amount of freight transported by rail and the number of passengers are increasing year by year. Any disruption to the passenger or freight transport stream can generate both financial and human losses. Such a disruption can be caused by the rail infrastructure being in poor condition. For this reason, the state of the infrastructure should be monitored periodically. One of the important elements of railroad infrastructure is the ballast. Its condition has a significant impact on the safety of rail traffic. The unevenness of the ballast surface is one of the indicators of its condition. For this reason, a regulation was introduced by Polish railway lines specifying the maximum threshold of ballast unevenness. This article presents an algorithm that allows for the detection of irregularities in the ballast. These irregularities are determined relative to the surface of the sleepers. The images used by the algorithm were captured by a laser triangulation system placed on a rail inspection vehicle managed by the Polish railway lines. The proposed solution has the following elements of novelty: (a) it presents a simple criterion for evaluating the condition of the ballast based on the measurement of its unevenness in relation to the level of the sleeper; (b) it treats ballast irregularity detection as an instance segmentation process and it compares two segmentation algorithms, Mask R-CNN and YOLACT, in terms of their application to ballast irregularity detection; and (c) it uses segmentation-related metrics—mAP (Mean Average Precision), IoU (Intersection over Union) and Pixel Accuracy—to evaluate the quality of the detection of ballast irregularity.

Railway signalling devices are used to ensure the safety of trains running on the railroad network. With the passage of time, the technical state of railway signalling devices deteriorates. During the exploitation of these devices, processes dependent on changes in technical states and changes in exploitation states occur. Achieving the maximum efficiency in the operation of a railway signalling system requires a shift from traditional corrective servicing to preventive service based on ongoing diagnosis of the technical state of the devices involved in train movements. An even greater opportunity is provided by the introduction of mathematical modelling methods into the exploitation testing of railway signalling devices and the prediction of their basic reliability indices well in advance. The proposed method allows the exploitation strategies for the signalling systems to be changed from a service-life-based strategy to a current-technical-state-based strategy while ensuring the required safety level.

Urban and suburban public transport constitute basics of functioning of modern, urbanized metropolises. It is a comfortable, economic and ecological means of transportation. Thus, a stable and fast growth of this solution. One of its components is the power supply system. It should allow functioning of the whole transportation system, maintaining the following criteria: energy efficiency and modernity. These criteria have contributed to creation and modernization of power supply systems. Where it comes to DC systems, such an investment includes: replacing 6-pulse rectifiers with 12-pulse rectifiers and raising rated supply voltage. In this article, the authors have presented research results, based on measurements of electrical energy parameters before and after a modernization of a suburban transportation traction system. These parameters have been divided into two groups. The first consists of parameters mentioned in the EN50160 norm. Another group consists of parameters not mentioned in the norm. What has been presented are waveforms and graphs showing these parameters. In the final part of the article a discussion on reasonability of introducing new, modernized traction power supply system for suburban transportation has been performed.

Bird feeding is one of the most widespread direct interactions between man and nature, and this has important social and environmental consequences. However, this activity can differ between rural and urban habitats, due to inter alia habitat structure, human behaviour and the composition of wintering bird communities. We counted birds in 156 squares (0.25 km 2 each) in December 2012 and again in January 2013 in locations in and around 26 towns and cities across Poland (in each urban area, we surveyed 3 squares and also 3 squares in nearby rural areas). At each count, we noted the number of bird feeders, the number of bird feeders with food, the type of feeders, additional food supplies potentially available for birds (bread offered by people, bins) and finally the birds themselves. In winter, urban and rural areas differ in the availability of food offered intentionally and unintentionally to birds by humans. Both types of food availability are higher in urban areas. Our findings suggest that different types of bird feeder support only those species specialized for that particular food type and this relationship is similar in urban and rural areas.

Urban environments cover vast areas with a high density of humans and their dogs and cats causing problems for exploitation of new resources by wild animals. Such resources facilitate colonization by individuals with a high level of neophilia predicting that urban animals should show more neophilia than rural conspecifics. We provided bird-feeders across urban environments in 14 Polish cities and matched nearby rural habitats, testing whether the presence of a novel item (a brightly coloured green object made out of gum with a tuft of hair) differentially delayed arrival at feeders in rural compared to urban habitats. The presence of a novel object reduced the number of great tits Parus major , but also the total number of all species of birds although differentially so in urban compared to rural areas. That was the case independent of the potentially confounding effects of temperature, population density of birds and the abundance of cats, dogs and pedestrians. The number of great tits and the total number of birds attending feeders increased in urban compared to rural areas independent of local population density of birds. This implies that urban birds have high levels of neophilia allowing them to readily exploit unpredictable resources in urban environments.

Background and objectives: The shared pathogenesis of psoriasis and atherosclerosis may be determined by assaying the levels of endothelial activation molecules. This study aimed at evaluating vascular cell adhesion molecule 1 (VCAM-1) and E-selectin serum concentrations, and atherosclerosis severity in patients with plaque psoriasis. It also aimed to determine the effects of methotrexate/adalimumab treatment for 12 weeks on the plasma levels of the aforementioned molecules. Materials and Methods: The study included 34 psoriasis patients (17 treated with methotrexate and 17 treated with adalimumab) and eight controls. The 10-year risk of a fatal cardiovascular disease, body mass index, Psoriasis Area and Severity Index, and body surface area were calculated for each subject. VCAM-1 and E-selectin levels were determined via an enzyme-linked immunosorbent assay at baseline and after 12 weeks. Results: Baseline E-selectin and VCAM-1 levels were higher in the adalimumab group than in the methotrexate and control groups. VCAM-1 levels decreased in the adalimumab (p = 0.02) and methotrexate groups (p = 0.008), while E-selectin levels decreased in the methotrexate group (p = 0.004). Conclusions: The results indicate a correlation between systemic psoriasis treatment and E-selectin and VCAM-1 plasma concentrations, which may be associated with the risk of cardiovascular disease development.

It is now more than a year since the first case of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) disease (COVID-19) was diagnosed in China. Current data suggest that pregnancy may not only be a risk factor for the development of severe forms of COVID-19, but that the SARS-CoV-2 infection may impact on common pregnancy complications as well. Healthy pregnant women are likely to be more susceptible to viral infection and therefore are at higher risk of developing severe COVID-19 because of adaptive changes in their immune and respiratory systems, their altered endothelial cell functions, and modified coagulation responses. However, studies show that most pregnant women diagnosed with COVID-19 developed mild-to-moderate symptoms and only a few of them have required critical care facilities. In contrast with preeclampsia, preeclampsia-like syndrome can resolve spontaneously following recovery from severe pneumonia and may not be an obstetric indication for delivery. Preeclampsia-like syndrome is one symptom of COVID-19, but its cause is different from obstetric preeclampsia and therefore not connected with placental failure. Vertical transmission of SARS-CoV-2 infection is rare but can probably occur. No evidence has been found that COVID-19 developed during pregnancy leads to unfavourable outcomes in the fetus. Most health authorities indicate that standard procedures should be used when managing pregnancy complications in asymptomatic women with confirmed SARS-CoV-2. Vaccines should not be withheld from pregnant and lactating individuals who otherwise meet the vaccination criteria.