Comparison of eigenanalysis and Ritz vector approaches for response spectrum analysis of soil-pile-bridge systems

Frequency-based analysis techniques such as response spectrum analysis (RSA) are widely used for designing bridges in seismically active regions. Two well-known analysis procedures that underlie RSA are the solution of the eigenproblem and the approximation of the solution to the eigenproblem (i.e., approximation of eigenvectors and eigenvalues) through use of force-dependent Ritz vectors. While frequency-based methods have achieved widespread adoption in practice, certain simplifications remain common, such as neglecting soil-structure interaction (SSI) due to a fixed-base assumption. In the present study, frequency-based techniques packaged within a research version of a design-oriented computational tool are employed to analyze, assess, and compare results obtained from RSA with use of the eigenanalysis, and separately, Ritz vector approaches. Importantly, for the bridge configurations analyzed, SSI is taken into account. As outcomes, the potential benefits of the Ritz vector approach (as well as modeling strategies) are demonstrated. The study outcomes are intended to aid practicing engineers when the need to account for SSI is recognized as pertinent to a given bridge seismic design application.

Improving the E-Commerce Business Model in a Sustainable Environment

The purpose of this study is to develop a comprehensive methodological approach to assess the sustainability of the e-commerce business model based on the integration of key performance indicators into a single vector of business model sustainability. The proposed vector approach allows for predicting and evaluating the effects of different kinds of measures, identifying and implementing the most effective tools for sustainable e-commerce business development. The methodology of this study is based on correlation, cluster and regression analysis. The scientific contribution of this study is the proposed methodological approach, which not only allows one to analyze business model sustainability, but also to compare companies in a competitive environment to determine the priorities of their functioning to achieve leadership positions on the background of sustainable development. The correlation analysis proved that in modern conditions, both economic and environmental components are significant for business model effectiveness in e-commerce. The clustering of the studied e-commerce companies provided an opportunity to take into account the peculiarities of the studied companies, to group them by similar performance indicators. This made it possible to develop more accurate regression models for each cluster. In this case, there is a correlation between the sustainability vector of the business model of a company and its assignment to a particular cluster. The conducted modeling and determination of the level of business model sustainability allowed for determining a relationship between it and the performance of e-commerce companies in the context of economic, environmental and social dimensions. At the same time, the results show that increasing the sustainability vector brings a company closer to the business sustainability benchmark.

Eurasianism and Foreign Policy of Russia

In order to determine the possibilities of wider application of the ideas of Eurasianism in the foreign policy of Russia, including the EAEU, but not limited to it, an analysis of various methods and approaches used for integration processes is carried out. At the same time, the current geopolitical situation and the factors of multi-vector approach in international relations are taken into account. It is also proposed to take in attention the role of identity in a broad sense as a political attraction. At the same time, various problems at the organizational, social, humanitarian and economic levels are also considered. The broad security factors that also play a role in the Eurasian integration are also taken into account. The relevance of this study is due not only to the implementation of strategic directions within the EAEU, but also to the general course towards multipolarity that Russia is pursuing. In addition, the crisis of liberal democracy in the West provides an additional opportunity for Russia to implement its own ideas and doctrines at the international level. The author believes that Eurasianism, including its classical version, can become one of the imperatives of Russia’s foreign policy.

CD8 T Cell Vaccines and a Cytomegalovirus-Based Vector Approach

The twentieth century witnessed a huge expansion in the number of vaccines used with great success in combating diseases, especially the ones caused by viral and bacterial pathogens. Despite this, several major public health threats, such as HIV, tuberculosis, malaria, and cancer, still pose an enormous humanitarian and economic burden. As vaccines based on the induction of protective, neutralizing antibodies have not managed to effectively combat these diseases, in recent decades, the focus has increasingly shifted towards the cellular immune response. There is substantial evidence demonstrating CD8 T cells as key players in the protection not only against many viral and bacterial pathogens, but also in the fight against neoplastic cells. Here, we present arguments for CD8 T cells to be considered as promising candidates for vaccine targeting. We discuss the heterogeneity of CD8 T cell populations and their contribution in the protection of the host. We also outline several strategies of using a common human pathogen, cytomegalovirus, as a vaccine vector since accumulated data strongly suggest it represents a promising approach to the development of novel vaccines against both pathogens and tumors.

Typical features of the etiology, pathogenesis and pathological morphology of chronic obstructive pulmonary disease in women and men

Chronic obstructive pulmonary disease (COPD) is a highly debilitating disease that poses a significant and increasing burden on women’s health. There is an increasing amount of information about gender-related differences in risk factors and the progression of COPD. However, very little attention is paid in scientific research and practice to COPD as a significant issue of women’s health. The challenges of COPD prevention in women can be overcome by a multi-vector approach, including increasing patient awareness of the disease, reducing the risk of its occurrence and further research on gender aspects (biological and cultural) that affect the risk of development and the rate of progression of COPD. The article reviews the current literature on this issue.

Chemogenetic Inhibition of Corticostriatal Circuits Reduces Cued Reinstatement of Methamphetamine Seeking

Methamphetamine (meth) causes enduring changes within the medial prefrontal cortex (mPFC) and the nucleus accumbens (NA). Projections from the mPFC to the NA have a distinct dorsal-ventral distribution, with the prelimbic (PL) mPFC projecting to the NAcore, and the infralimbic (IL) mPFC projecting to the NAshell. Inhibition of these circuits has opposing effects on cocaine relapse. Inhibition of PL-NAcore reduces cued reinstatement of cocaine seeking and IL-NAshell inhibition reinstates cocaine seeking. Meth, however, exhibits a different profile, as pharmacological inhibition of either the PL or IL decrease cued reinstatement of meth-seeking. The potentially opposing roles of the PL-NAcore and IL-NAshell projections remain to be explored in the context of cued meth seeking. Here we used an intersectional viral vector approach that employs a retrograde delivery of Cre from the NA and Cre-dependent expression of DREADD in the mPFC, in both male and female rats to inhibit or activate these parallel pathways. Inhibition of the PL-NAcore circuit reduced cued reinstatement of meth seeking under short and long-access meth self-administration and after withdrawal with and without extinction. Inhibition of the IL-NAshell also decreased meth cued reinstatement. Activation of the parallel circuits was without an effect. These studies show that inhibition of the PL-NAcore or the IL-NAshell circuits can inhibit reinstated meth seeking. Thus, the neural circuitry mediating cued reinstatement of meth seeking is similar to cocaine in the dorsal, but not ventral, mPFC-NA circuit.

Bearing Fault Detection in Induction Motors Using Line Currents

This paper focuses on the development of a bearing fault detection model for induction motors using line currents. The graphical and numerical analysis of the model has been developed using the park's vector approach and envelope based on the Hilbert transform. The proposed model has been evaluated on currents measured from eight different types of induction motors. The graphical results from the Concordia pattern between d- and q-components of stator currents show that healthy bearing behaviour is circular compared to the faulty bearing's elliptical. The numerical results show that the minimum and maximum envelope of d- and q-components of stator currents is more significant than one. The sum of Kurtosis for the envelope of d- and q-components of stator currents is less than 5.0.