Resource retrial queue with two orbits and negative customers

In this paper, a multi-server retrial queue with two orbits is considered. There are two arrival processes of positive customers (with two types of customers) and one process of negative customers. Every positive customer requires some amount of resource whose total capacity is limited in the system. The service time does not depend on the customer’s resource requirement and is exponentially distributed with parameters depending on the customer’s type. If there is not enough amount of resource for the arriving customer, the customer goes to one of the two orbits, according to his type. The duration of the customer delay in the orbit is exponentially distributed. A negative customer removes all the customers that are served during his arrival and leaves the system. The objects of the study are the number of customers in each orbit and the number of customers of each type being served in the stationary regime. The method of asymptotic analysis under the long delay of the customers in the orbits is applied for the study. Numerical analysis of the obtained results is performed to show the influence of the system parameters on its performance measure

Communication of COVID-19 consequences in the Baltic States inforsphere

This article seeks to describe the dynamics of COVID-19 in the Baltic States and to analyse the ways of communicating the threat and its consequences. Particular attention is paid to the media strategies pursued in the study area. The research is based on Russian and English texts from the Baltic media, WHO official documents and datasets, as well as initiatives of the Baltic Sea region organisations (2020) counteracting COVID-19. A combination of these sources builds up an objective view of the situation and demonstrates how the pandemic and its consequences are represented in public consciousness given a certain pragmatic goal. The pandemic is a new type of threat; its consequences demonstrate a tendency towards negative synergy and a category shift from soft threats to hard ones. The research shows that several key strategies - counter-active, projective, conservative, mobilising, resilient, and reflective - are used to communicate the threat and its consequences in the media

Multi-service resource queue with the multy-component Poisson arrivals

In many papers devoted to telecommunication systems, multiservice queueing models with heterogeneous customer arrivals are given. As a rule, there is streaming traffic, corresponding to the audio and video conference, and elastic traffic, corresponding to the data and file transmission. Different types of traffic require different quality of service, therefore the multi-service systems are also differentiated service systems. Such papers are aimed at developing a framework for estimating the quality of service indicators in new generation multi-service networks. This paper considers a multiservice resource queueing system with three Poisson arrivals, one of which is splitting. The equation for the probabilities distribution of the total resource amounts on the system blocks is compiling by the dynamic screening method, and using the characteristic function of the stationary distribution, the solution is obtaining. The numerical characteristics of the system performance are obtained by the method of moments using characteristic function. A numerical example shows that arrivals intensity growing increases optimal total resource amounts on system blocks in the system with limited resources, and the splitting arrivals affect the correlation between total resource amounts

Local therapy of cancer with free IL-2

This is a position paper about the therapeutic effects of locally applied free IL-2 in the treatment of cancer. Local therapy: IL-2 therapy of cancer was originally introduced as a systemic therapy. This therapy led to about 20% objective responses. Systemic therapy however was very toxic due to the vascular leakage syndrome. Nevertheless, this treatment was a break-through in cancer immunotherapy and stimulated some interesting questions: Supposing that the mechanism of IL-2 treatment is both proliferation and tumoricidal activity of the tumor infiltrating cells, then locally applied IL-2 should result in a much higher local IL-2 concentration than systemic IL-2 application. Consequently a greater beneficial effect could be expected after local IL-2 application (peritumoral = juxtatumoral, intratumoral, intra-arterial, intracavitary, or intratracheal = inhalation). Free IL-2: Many groups have tried to prepare a more effective IL-2 formulation than free IL-2. Examples are slow release systems, insertion of the IL-2 gene into a tumor cell causing prolonged IL-2 release. However, logistically free IL-2 is much easier to apply; hence we concentrated in this review and in most of our experiments on the use of free IL-2. Local therapy with free IL-2 may be effective against transplanted tumors in experimental animals, and against various spontaneous carcinomas, sarcomas, and melanoma in veterinary and human cancer patients. It may induce rejection of very large, metastasized tumor loads, for instance advanced clinical tumors. The effects of even a single IL-2 application may be impressive. Not each tumor or tumor type is sensitive to local IL-2 application. For instance transplanted EL4 lymphoma or TLX9 lymphoma were not sensitive in our hands. Also the extent of sensitivity differs: In Bovine Ocular Squamous Cell Carcinoma (BOSCC) often a complete regression is obtained, whereas with the Bovine Vulval Papilloma and Carcinoma Complex (BVPCC) mainly stable disease is attained. Analysis of the results of local IL-2 therapy in 288 cases of cancer in human patients shows that there were 27% Complete Regressions (CR), 23% Partial Regressions (PR), 18% Stable Disease (SD), and 32% Progressive Disease (PD). In all tumors analyzed, local IL-2 therapy was more effective than systemic IL-2 treatment. Intratumoral IL-2 applications are more effective than peritumoral application or application at a distant site. Tumor regression induced by intratumoral IL-2 application may be a fast process (requiring about a week) in the case of a highly vascular tumor since IL-2 induces vascular leakage/edema and consequently massive tumor necrosis. The latter then stimulates an immune response. In less vascular tumors or less vascular tumor sites, regression may require 9–20 months; this regression is mainly caused by a cytotoxic leukocyte reaction. Hence the disadvantageous vascular leakage syndrome complicating systemic treatment is however advantageous in local treatment, since local edema may initiate tumor necrosis. Thus the therapeutic effect of local IL-2 treatment is not primarily based on tumor immunity, but tumor immunity seems to be useful as a secondary component of the IL-2 induced local processes. If local IL-2 is combined with surgery, radiotherapy or local chemotherapy the therapeutic effect is usually greater than with either therapy alone. Hence local free IL-2 application can be recommended as an addition to standard treatment protocols. Local treatment with free IL-2 is straightforward and can readily be applied even during surgical interventions. Local IL-2 treatment is usually without serious side effects and besides minor complaints it is generally well supported. Only small quantities of IL-2 are required. Hence the therapy is relatively cheap. A single IL-2 application of 4.5 million U IL-2 costs about 70 Euros. Thus combined local treatment may offer an alternative in those circumstances when more expensive forms of treatment are not available, for instance in resource poor countries

Asymptotic stationary probability distribution of total amount of physics experimental data

A mathematical model has been constructed for processing of physics experimental data in the form of a twophas

On a total amount of occupied resource in the system with parallel service and renewal arrival process

Resource queueing systems has emerged as a powerful tool to calculate the capacity of a base station that serves customers using video services. In this scenario, two types of resources are used: uplink and downlink bandwidth. This means that if there is not enough bandwidth to meet the requirements, the client will not be able to connect. Network designers set the task of determining the optimal value of the cell capacity in order to minimize the loss of connection and downtime of radio resources due to which the operator may suffer losses. To address such issues, this paper carries out an analytical study of a resource queue with random resource requirements. In more detail, the paper deals with a renewal arrival process and the parallel service of each customer in two infinite-server blocks. Balance equations are solved under the asymptotic condition of the high intensity of the arrival process and it is obtained that the two-dimensional stationary probability distribution of the amount of occupied resources in both server blocks is approximately two-dimensional Gaussian. Parameters of the distribution are also derived

Resource QS with the requests duplication at the second phase and renewal arrival process

In this paper, a resource queueing system with renewal arrival process, arbitrary service time distribution and requests duplication at the second phase is considered. In more detail, we apply the dynamic screening method to obtain the asymptotic expression for the stationary probability distribution of the total amount of occupied resource in the system. Finally, we verify the goodness of the obtained Gaussian approximation by means of discrete event simulation

Using infinite‑server resource queue with splitting of requests for modeling two‑channel data transmission

New Radio Access Technology 3GPP New Radio has become the fundamental wireless technology in the fifth-generation networks, which allows us to achieve high data rates due to the ability to work in the millimeter-wave band. But the key feature and the main problem of 5G New Radio networks is that people themselves, cars, buildings, etc. are signal blockers, while the base stations of the fourth generation networks have widescreen broadcasting and such small obstacles do not cause loss of connection. Service providers and mobile operators are already testing the proposed technology. In this connection, the scientific community has the task of analyzing the performance of these systems and increasing it in the future. Currently, there are known studies of “basic” mathematical models of such networks. By this term, we mean models built in the simplest possible assumptions. However, due to the justified necessity of introducing new technology into the daily lives of subscribers, service providers pose the scientific community with the task of analyzing the effectiveness of the most appropriate mathematical models. For example, a technology of splitting transmitted data into two streams using as 5G and both 4G transmission technologies is considered now by 3GPP Project Coordination Group. The paper is devoted to such a problem. We consider a mathematical model of the message transmitting with the implementation of the splitting function in the communication networks of New Radio technology in the form of a resource queueing system with a renewal arrival process and non-exponential service. For this problem, an approximation of a stationary two-dimensional probability distribution of the number of occupied resources in parallel service units is obtained. It is shown that this approximation coincides with the Gaussian distribution, and its area of applicability is shown

Genetic and Clinical Features of Shwachman-Diamond Syndrome in Russian Population: Prospective Study

Background. Shwachman-Diamond syndrome (SDS) is the rare genetic autosomal recessive disorder with pathogenic variants in SBDS gene. The spectrum of SBDS gene variants in patients with SDS and features of disease course have not been studied before in Russian population.Objective. The aim of the study was to describe all the variants of SBDS gene and clinical and laboratory abnormalities in children with SDS. Methods. In this prospective study exocrine pancreatic function was estimated by amylase and lipase activity in blood, steatorrhea presence and stool elastase levels during the initial hospitalization. Haematological disorders were analysed by complete blood count. Bone abnormalities were diagnosed via X-ray imaging. Growth delay was established due to anthropometry indicators and percentile curves. Molecular genetic testing was performed with using next generation sequencing and Senger sequencing.Results. Pathogenic variants in SBDS gene (8 in general) were revealed in 25 (89%) out of 28 children with SDS. The most common variant (in 23 patients, 82%) was с.258+2T>C, and in 18 cases it was in compound heterozygous state with c.183_184delTAinsCT. Two patients had с.653G>A (p.Arg218Gln) variant and for one patient for every of the following variants: c.258+1G>A, c.107delT, с.356G>A, c.297_300delAAGA, c.338C>T. All children with SDS had growth delay, in 11 (39%) cases we revealed bone abnormalities. In blood samples of 24 (86%) children we revealed neutropenia and less frequently anemia and thrombocytopenia. The stool elastase I decreased activity (< 200 pg/g) was revealed in 26 (92%) patients. 21 (75%) children had cytolysis syndrome.Conclusion. Pathogenic variants of SBDS gene were revealed in majority of Russian children with SDS. The most frequent are c.258+2T>C and c.183_184delTAinsCT variants. Clinical signs of Shwachman-Diamond syndrome manifest since birth with growth delay, steatorrhea and haematological disorders

Soft Tissue Sarcoma Study: Association of Genetic Alterations in the Apoptosis Pathways with Chemoresistance to Doxorubicin

Soft tissue sarcomas (STS) are heterogeneous cancers with more than 100 histological subtypes, different in molecular alterations, which make its personalized therapy very complex. Gold standard of chemotherapy for advanced STS includes combinations of Doxorubicin and Ifosfamide or Gemcitabine and Docetaxel. Chemotherapy is efficient for less than 50% of patients and it is followed by a fast development of drug resistance. Our study was directed to the search of genetic alterations in cancer cells associated with chemoresistance of undifferentiated pleomorphic and synovial sarcomas to the abovementioned genotoxic drugs. We analyzed chemoresistance of cancer cells in vitro using primary STS cultures and performed genetic analysis for the components of apoptotic signaling. In 27% of tumors, we revealed alterations in TP53, ATM, PIK3CB, PIK3R1, NTRK1, and CSF2RB. Cells from STS specimens with found genetic alterations were resistant to Dox, excluding the only one case when TP53 mutation resulted in the substitution Leu344Arg associated with partial oligomerization loss and did not cause total loss of TP53 function. Significant association between alterations in the components of apoptosis signaling and chemoresistance to Dox was found. Our data are important to elaborate further the therapeutic strategy for STS patients with alterations in apoptotic signaling