ABSTRACT
The study of the preparation phase of large earthquakes is essential to understand the physical processes involved, and potentially useful also to develop a future reliable short-term warning system. Here we analyse electron density and magnetic field data measured by Swarm three-satellite constellation for 4.7 years, to look for possible in-situ ionospheric precursors of large earthquakes to study the interactions between the lithosphere and the above atmosphere and ionosphere, in what is called the Lithosphere-Atmosphere-Ionosphere Coupling (LAIC). We define these anomalies statistically in the whole space-time interval of interest and use a Worldwide Statistical Correlation (WSC) analysis through a superposed epoch approach to study the possible relation with the earthquakes. We find some clear concentrations of electron density and magnetic anomalies from more than two months to some days before the earthquake occurrences. Such anomaly clustering is, in general, statistically significant with respect to homogeneous random simulations, supporting a LAIC during the preparation phase of earthquakes. By investigating different earthquake magnitude ranges, not only do we confirm the well-known Rikitake empirical law between ionospheric anomaly precursor time and earthquake magnitude, but we also give more reliability to the seismic source origin for many of the identified anomalies.
ABSTRACT
In the present study we have investigated the biological effects on thymus lymphocytes resulting from Escherichia coli lipopolysaccharide (LPS) treatment in young adult mice. It has been established that LPS induces the following effects: (a) a dose-dependent reduction of thymus weight contemporaneous with a rise in the anti-LPS antibody response; (b) an increase of killer activity of thymus cells; (c) an enhancement of thymocytes helper activity; (d) a reduction of theta-positive cells in the thymus; (e) a cellular depletion in the thymus cortex. These data, indicating that LPS selects in the thymus a population of cells more efficient in expressing both killer and helper functions, are interpreted as caused by an increased rate of cortisol secretion induced by the LPS treatment.
Subject(s)
Lipopolysaccharides/immunology , Polysaccharides, Bacterial/immunology , Animals , Antibody Formation , Antibody-Producing Cells , Antigens, Bacterial , Bone Marrow Cells , Bone Marrow Transplantation , Cytotoxicity Tests, Immunologic , Escherichia coli/immunology , Graft vs Host Reaction , Male , Mice , Organ Size , Thymus Gland/anatomy & histology , Thymus Gland/immunology , Transplantation, HomologousABSTRACT
The effect of LPS injection on mouse thymocytes was examined by in vitro stimulation with PHA and Con A. Thymocytes from LPS treated mice were found more responsive than normal thymocytes to PHA and Con A. The increase of responsiveness was different for PHA and Con A, and dependent on the dose of LPS injected. This dose dependency suggests that LPS in vivo modifies the thymocyte population by progressively eliminating T1 cells and selecting T2 cells. These effects seem to be mediated by corticosteroids because they were prevented by adrenalectomy, a finding in agreement with the notion that the injection of cortisone induces similar cell changes in the thymus.
