Quality of service at the computer networks based on internet

А framework for the emerging computer networks quality of Internet service is presented. Two important components of the framework are considered: integrated service and differentiated service. They are described and problems related to their implementation are discussed. Two broadly classified algorithms are investigated: scheduling and queue management algorithms. The model of the average time delay for the type packet is presented.Запропоновано структуру забезпечення якості надання послуг Internet. Розглянуто два важливі компоненти цієї структури: інтегроване та диференційоване обслуговування, їх реалізацію та пов’язані з нею проблеми. Досліджено два алгоритма: планування і управління чергою. Запропоновано модель даних, яка базується на теорії масового обслуговування.Предложена структура обеспечения качества предоставления услуг Internet. Рассмотрены два важных компонента этой структуры: интегрированное и дифференцированное обслуживание, их реализация и связанные с ней проблемы. Исследованы два алгоритма: планирования и управления очередью. Предложена модель данных, базирующаяся на теории массового обслуживания

Permissive expansion and homing of adoptively transferred T cells in tumor-bearing hosts

Activated T cells expressing endogenous or transduced TCRs are two cell types currently used in clinical adoptive T-cell therapy. The ability of these cells to recognize their antigen, expand, and traffic to the tumor site are the initial steps necessary for successful therapy. In this study, we used in vivo bioluminescent imaging (BLI) of Renilla luciferase (RLuc) expressing T cells to evaluate the ability of adoptively transferred T cells to survive, expand and home to tumor site in vivo. Using this method, termed RT-Rack (Rluc T cell tracking), we followed T-cell response against tumors in vivo. Expansion and homing of adoptively transferred T cells were antigen dependent, but independent of the host immune status. Moreover, we successfully detected T-cell response to small and large tumors, including autochthonous liver tumors. The adoptively transferred T cells were not ignorant or excluded in a partially tolerant host, which expressed low level of the target in the periphery. Using T cell receptor-engineered T cells, we showed the ability of these cells to respond in tumor-bearing hosts by expanding and homing to the tumor site. In all these models, the host immune status, the nature of the tumor or of the antigen, the tumor size, and the presence of the targeted antigen in the periphery did not prevent the adoptively transferred T cells from responding by expanding and homing to the tumor. However, T cells had higher expression of the inhibitory receptor PD1 and reduced functional activity when a self-antigen was targeted

Fas expression by tumor stroma is required for cancer eradication

The contribution of molecules such as perforin, IFN-{gamma} (IFN{gamma}), and particularly Fas ligand (FasL) by transferred CD8(+) effector T (T(E)) cells to rejection of large, established tumors is incompletely understood. Efficient attack against large tumors carrying a surrogate tumor antigen (mimicking a "passenger" mutation) by T(E) cells requires action of IFN{gamma} on tumor stroma cells to avoid selection of antigen-loss variants. Because "cancer-driving" antigens (CDAs) are rarely counterselected, IFN{gamma} may be expected to be dispensable in elimination of cancers by targeting a CDA. Here, initial regression of large, established tumors required neither IFNγ, FasL, nor perforin by transferred CD8(+) T(E) cells targeting Simian Virus (SV) 40 large T as CDA. However, cytotoxic T(E) cells lacking IFN{gamma} or FasL could not prevent relapse despite retention of the rejection antigen by the cancer cells. Complete tumor rejection required IFN{gamma}-regulated Fas by the tumor stroma. Therefore, T(E) cells lacking IFNγ or FasL cannot prevent progression of antigenic cancer because the tumor stroma escapes destruction if its Fas expression is down-regulated