Pneumonia Due to Mycoplasma in Gnotobiotic Mice I. Pathogenicity of \u3cem\u3eMycoplasma pneumoniae\u3c/em\u3e, \u3cem\u3eMycoplasma salivarium\u3c/em\u3e, and \u3cem\u3eMycoplasma pulmonis\u3c/em\u3e for the Lungs of Conventional and Gnotobiotic Mice

Pneumonia due to mycoplasma in gnotobiotic mice. I. Pathogenicity of Mycoplasma pneumoniae, Mycoplasma salivarium, and Mycoplasma pulmonis for the lungs of conventional and gnotobiotic mice. J. Bacteriol. 92:1154–1163. 1966.—Two species of mycoplasma of human origin, Mycoplasma pneumoniae and M. salivarium, were tested for their ability to produce respiratory disease in the Ha/ICR mouse when inoculated by the intranasal route. The mouse pathogen M. pulmonis was studied as a positive control. Conventional and gnotobiotic Ha/ICR mice were employed, the latter to provide a system free from indigenous mycoplasma and bacteria. Pneumonia from which mycoplasma were isolated was produced in all groups of the conventional Ha/ICR mice, including those inoculated with sterile broth. Only M. pulmonis produced disease when inoculated intranasally into the gnotobiotic mice, and the gross and microscopic lesions resembled those described in conventional mice. The gnotobiotic mouse provided a tool to study the pathogenicity of different mycoplasma species, and indicated marked differences in host specificity that could not be clearly seen when conventional mice were used

Интенсивная технология при сооружении земляного полотна в криолитозоне

[For the English abstract and full text of the article please see the attached PDF-File (English version follows Russian version)].ABSTRACT An intensive technological regime for increasing the stability of weak soils is proposed to ensure safety of the roadbed on the site with the eternally frozen base of the Northern latitudinal railway Salekhard-Nadym. It is shown that it is necessary to take into account talik zones at the design stage, which can cause various deformations. On the basis of the fundamental principles of the mechanics of frozen soils, technological regularities are established f o r increasing the strength characteristics which include the angle of internal friction and cohesion of soil with decreasing humidity and draining water from the active layer and talik beyond the construction site. The application of intensive technology for reinforcing the roadbed during the construction of routes in the permafrost zone is substantiated. Keywords: railway, safety, stability, eternally frozen soils, roadbed, intensive technologyТекст аннотации на англ. языке и полный текст статьи на англ. языке находится в прилагаемом файле ПДФ (англ. версия следует после русской версии).Предложен интенсивный технологический режим повышения стабильности слабых грунтов при сооружении земляного полотна на участке с многолетнемёрзлым основанием. На примере Северного широтного хода показана эффективность применения фундаментальных положений механики мёрзлых грунтов, установлены технологические закономерности повышения прочностных характеристик - угла внутреннего трения и сцепления грунта при уменьшении влажности и отводе воды из деятельного слоя и талика за пределы строительной площадки. Обосновано применение интенсивной технологии для упрочнения земляного полотна при строительстве путей сообщения в криолитозоне

Pneumonia due to Mycoplasma in Gnotobiotic Mice II. Localization of Mycoplasma pulmonis in the Lungs of Infected Gnotobiotic Mice by Electron Microscopy

Organick, Avrum B. (Marquette University School of Medicine, Milwaukee, Wis.), Kenneth A. Siegesmund, and Irving I. Lutsky. Pneumonia due to mycoplasma in gnotobiotic mice. II. Localization of Mycoplasma pulmonis in the lungs of infected gnotobiotic mice by electron microscopy. J. Bacteriol. 92:1164–1176. 1966.—Lesions in lungs of gnotobiotic mice inoculated intranasally with Mycoplasma pulmonis were examined by electron microscopy after osmic acid fixation. At 1 week after infection, mycoplasma cells were found in large numbers in the bronchi at the surface of bronchial epithelial cells and, in smaller numbers, in the alveoli where active phagocytosis by polymorphonuclear leukocytes (PMN) occurred. Cytopathic changes in underlying bronchial epithelial cells, not apparent by light microscopy, were observed. At 3 weeks after infection, mycoplasma cells were rarely seen in the bronchi, and were no longer seen free in the alveolar spaces or within PMN. Lungs examined after glutaraldehyde fixation 1 week after infection confirmed the presence of mycoplasma cells in the alveolar spaces and within phagocytic vacuoles of PMN, but also revealed numerous ring forms within granular pneumocytes. These forms seemed to represent intracytoplasmic developmental stages of M. pulmonis, in which elementary bodies appeared in large numbers

Technological Features of Construction and Reconstruction of Geotechnical Structures in the Arctic Zone

Production engineering methods and geotechnical instrumentation for the construction and reconstruction of railway beds in high temperatures in the Arctic zone are proposed. High-technology construction facilitates the development of transport infrastructure of the energy-producing industries in the Arctic. The example of the Northern Latitudinal Railway (NLR) highlights the probability of dangerous cryogenic processes and phenomena during works, such as waterlogging and the structural decline of the active soil layer, the development of taliks, and frost cracking, which lead to a decrease in bearing capacity of soil. The features of the construction and production plans used at the sites of railway embankment reconstruction with heavy-duty equipment are outlined. New process control methods have been developed based on the selection of and systematic changes in the parameters of maximum permissible construction loads depending on the results of geotechnical structure monitoring. The structural diagram of high technology for strengthening the weak subgrade soil under the conditions of talik development is substantiated. In order to regulate intensive process parameters, the vehicle fleet needs to be equipped with positioning devices and automation process control systems. The effectiveness of process control in terms of improving the reliability and accelerating roadbed consolidation is substantiated