Nanotubes connecting B lymphocytes: High impact of differentiation-dependent lipid composition on their growth and mechanics

Nanotubes (NTs) are thin, long membranous structures forming novel, yet poorly known communication pathways between various cell types. Key mechanisms controlling their growth still remained poorly understood. Since NT-forming capacity of immature and mature B cells was found largely different, we investigated how lipid composition and molecular order of the membrane affect NT-formation. Screening B cell lines with various differentiation stages revealed that NT-growth linearly correlates with membrane ganglioside levels, while it shows maximum as a function of cholesterol level. NT-growth of B lymphocytes is promoted by raftophilic phosphatidylcholine and sphingomyelin species, various glycosphingolipids, and docosahexaenoic acid-containing inner leaflet lipids, through supporting membrane curvature, as demonstrated by comparative lipidomic analysis of mature versus immature B cell membranes. Targeted modification of membrane cholesterol and sphingolipid levels altered NT-forming capacity confirming these findings, and also highlighted that the actual lipid raft number may control NT-growth via defining the number of membrane-F-actin coupling sites. Atomic force microscopic mechano-manipulation experiments further proved that mechanical properties (elasticity or bending stiffness) of B cell NTs also depend on the actual membrane lipid composition. Data presented here highlight importance of the lipid side in controlling intercellular, nanotubular, regulatory communications in the immune system

GIS ANALYSIS OF POPULATION EVACUATION FROM FLASH FLOODS – CASE STUDY, ȚÂȘLA DRAINAGE BASIN, ROMANIA

Țâșla watershed, composing sub-basin of the larger Vișeu basin, is a highly anthropic area, with an extremely packed residential and transportation infrastructure, mainly along the Țâșla watercourse. Mining and tourist activities have always been and still are the outcome of a great natural potential, this fact leading to the area always getting ranked as one of the top economic centers in Maramureș County. The high frequency of flash flooding is jeopardizing the socio-economic progress of the area, causing substantial damage. This paper’s goal is the adaptation of a GIS tool, proposed by researchers from the U.S. Geological Survey – USGS (Jeanne M. Jones, Peter Ng, Nathan J. Wood, 2014), used in the flash flooding population evacuation analysis, etc. This method is based upon the digital elevation model, land cover, hazard zones and safe zones analysis. The results (evacuation time, evacuation corridors, etc) can be a relevant contribution to the decision making management of the emergency situations

Invertebrate fossils from cave sediments: a new proxy for pre-Quaternary paleoenvironments

Five samples of clastic sediments from interior cave facies taken in three Slovenian relic caves (Trhlovca, Račiška pečina, and a cave in Črnotiče Quarry, Classical Karst, SW Slovenia) provided invertebrate fossil remains. Most of them belong to Oribatida but sparse individuals of Cladocera and insects were also identified. They represent the first pre-Quaternary invertebrate fossils found in sediments of continental temperate climate. The Pliocene/Pleistocene age of the sediments was determined by paleomagnetic dating chronologically calibrated by micromammal biostratigraphy. Invertebrate fossils could be validated as new proxy for the study of cave sediments due to their suitability for ecological and paleogeographic correlations in caves and outside the caves. They also bring additional information about cave formation and karst hydraulic regime in the area. Although the number of remains was very low, it is evidence that climatic conditions in caves allow a better preservation of fossil remains of some groups as compared to most of the surface habitats. This may open a new direction in the study of cave sediments