Смещение уровня значимости и мощности критерия при конечной крутизне переходной характеристики

Исследованы смещения уровня значимости и мощности критерия, когда при проверке статистических гипотез с использованием правила Неймана – Пирсона в качестве модели переходной характеристики логической схемы используется простая функция ошибок. Смещения рассчитаны для рэлеевских функций распределения. В качестве одного из варьируемых параметров используется обобщенное отношение сигнал-помеха. Нахмансон Г. С., Костенников В. С., Ницак Д. А. Смещение уровня значимости и мощности критерия при конечной крутизне переходной характеристики. Ural Radio Engineering Journal. 2022;6(4):378–389. DOI: 10.15826/urej.2022.6.4.002

Significance Level and the Strength of Test Shift Through the Finite Rate of the Transient Response

Поступила: 12.10.2022. Принята в печать: 14.11.2022.Received: 12.10.2022. Accepted: 14.11.2022.Исследованы смещения уровня значимости и мощности критерия, когда при проверке статистических гипотез с использованием правила Неймана – Пирсона в качестве модели переходной характеристики логической схемы используется простая функция ошибок. Смещения рассчитаны для рэлеевских функций распределения. В качестве одного из варьируемых параметров используется обобщенное отношение сигнал-помеха.A significance level and the strength of test shifts are studied then the error function as a transient response model of logical gate is used for testing of statistical hypothesis with Neumann-Pearson criterion. Shifts are rated for Rayleigh accumulated distributions. The generalized signalto-noise ratio is used as one of the variable parameters. The paper reveals that the finite slope of the transient response curve of logical gate results in a type I error increase. The significance level lock leads to bottom of critical region increase and the strength of test decrease in return. The twofold increase of the slope of the transient response curve leads to both the type I error and the bottom of critical region and the strength of test shifts decrease about 12 dB. The twofold increase of generalized signal-to-noise ratio causes the rise of the maximum displacement of a test power functions more than 3 dB up. As this takes place the extremum abscissa is diminished

Blood serum cytokines in patients with subacute spinal cord injury: A pilot study to search for biomarkers of injury severity

Background. Despite considerable interest in the search for a spinal cord injury (SCI) therapy, there is a critical need to develop a panel of diagnostic biomarkers to determine injury severity. In this regard, there is a requirement for continuing research into the fundamental processes of neuroinflammatory and autoimmune reactions in SCI, identifying changes in the expression of cytokines. Methods. In this pilot study, an extended multiplex analysis of the cytokine profiles in the serum of patients at 2 weeks post-SCI (n = 28) was carried out, together with an additional assessment of neuron-specific enolase (NSE) and vascular endothelial growth factor (VEGF) levels by enzyme-linked immunosorbent assay. A total of 16 uninjured subjects were enrolled as controls. Results. The data obtained showed a large elevation of IFNγ (>52 fold), CCL27 (>13 fold), and CCL26 (>8 fold) 2 weeks after SCI. The levels of cytokines CXCL5, CCL11, CXCL11, IL10, TNFα, and MIF were different between patients with baseline American Spinal Injury Association Impairment Scale (AIS) grades of A or B, whilst IL2 (>2 fold) and MIP-3a (>6 fold) were significantly expressed in the cervical and thoracic regions. There was a trend towards increasing levels of NSE. However, the difference in NSE was lost when the patient set was segregated based on AIS group. Conclusions. Our pilot research demonstrates that serum concentrations of cytokines can be used as an affordable and rapid detection tool to accurately stratify SCI severity in patients

Mesenchymal stem cell therapy for spinal cord contusion: A comparative study on small and large animal models

© 2019 by the authors. Licensee MDPI, Basel, Switzerland. Here, we provide a first comparative study of the therapeutic potential of allogeneic mesenchymal stem cells derived from bone marrow (BM-MSCs), adipose tissue (AD-MSCs), and dental pulp (DP-MSCs) embedded in fibrin matrix, in small (rat) and large (pig) spinal cord injury (SCI) models during subacute period of spinal contusion. Results of behavioral, electrophysiological, and histological assessment as well as immunohistochemistry and real-time polymerase chain reaction analysis suggest that application of AD-MSCs combined with a fibrin matrix within the subacute period in rats (2 weeks after injury), provides significantly higher post-traumatic regeneration compared to a similar application of BM-MSCs or DP-MSCs. Within the rat model, use of AD-MSCs resulted in a marked change in: (1) restoration of locomotor activity and conduction along spinal axons; (2) reduction of post-traumatic cavitation and enhancing tissue retention; and (3) modulation of microglial and astroglial activation. The effect of an autologous application of AD-MSCs during the subacute period after spinal contusion was also confirmed in pigs (6 weeks after injury). Effects included: (1) partial restoration of the somatosensory spinal pathways; (2) reduction of post-traumatic cavitation and enhancing tissue retention; and (3) modulation of astroglial activation in dorsal root entry zone. However, pigs only partially replicated the findings observed in rats. Together, these results indicate application of AD-MSCs embedded in fibrin matrix at the site of SCI during the subacute period can facilitate regeneration of nervous tissue in rats and pigs. These results, for the first time, provide robust support for the use of AD-MSC to treat subacute SCI