Analysis of argon concentration anomalies in underground water in Kamchatka (Russia)

In this paper we present the results of characterising time series of the argon content of groundwater recorded in the Kamchatka area of Russia. The problems of correlating anomalies in the argon data with seismic activity are explored. A new statistical technique for relating anomalies to geophysical observations based on Markov Chain Monte Carlo modelling methods is outlined

Groundwater Argon content on the occasion of strong earthquakes in a seismogenetic area of Kamchatka (Russia)

Since 1988 the argon content in underground water has been measured at the Morosnaya well, in the Kamchatka peninsula, with a sampling frequency of three days. In the same well other gases and ions dissolved in water are measured, together with flow rate, pH and temperature. The most active seismogenetic area in Kamchatka is that located offshore, along the south-eastern coast of the peninsula. The strongest earthquakes in this area occurred on March 2, 1992 (M47.1), November 13, 1993 (M47.0) and June 21, 1996 (M47.1), within a distance of 200 km from the well. The focal depth of the earthquakes of 1992 and 1993 was 20 and 40 km, respectively. The earthquake which occurred in 1996 was very shallow; a focal depth of few kilometres was estimated. No anomalies in the argon or other dissolved gas concentration were observed on the occasion of 1992 and 1993 earthquakes; on the other hand, a very clear preseismic anomaly appeared in the concentration of argon and nitrogen on the occasion of the 1996 earthquake. The behaviour of the ion content was opposite; no anomaly on the occasion of the last earthquake and clear preseismic anomalies on the occasion of the two former earthquakes appeared. A possible explanation of the quoted behaviour of dissolved gases and ions in groundwater according to the different focal depth of the subsequent earthquakes is presented

Geographical and temporal distribution of SARS-CoV-2 clades in the WHO European Region, January to June 2020

We show the distribution of SARS-CoV-2 genetic clades over time and between countries and outline potential genomic surveillance objectives. We applied three available genomic nomenclature systems for SARS-CoV-2 to all sequence data from the WHO European Region available during the COVID-19 pandemic until 10 July 2020. We highlight the importance of real-time sequencing and data dissemination in a pandemic situation. We provide a comparison of the nomenclatures and lay a foundation for future European genomic surveillance of SARS-CoV-2.Peer reviewe

Whole-genome sequencing reveals host factors underlying critical COVID-19

Critical COVID-19 is caused by immune-mediated inflammatory lung injury. Host genetic variation influences the development of illness requiring critical care1 or hospitalization2,3,4 after infection with SARS-CoV-2. The GenOMICC (Genetics of Mortality in Critical Care) study enables the comparison of genomes from individuals who are critically ill with those of population controls to find underlying disease mechanisms. Here we use whole-genome sequencing in 7,491 critically ill individuals compared with 48,400 controls to discover and replicate 23 independent variants that significantly predispose to critical COVID-19. We identify 16 new independent associations, including variants within genes that are involved in interferon signalling (IL10RB and PLSCR1), leucocyte differentiation (BCL11A) and blood-type antigen secretor status (FUT2). Using transcriptome-wide association and colocalization to infer the effect of gene expression on disease severity, we find evidence that implicates multiple genes—including reduced expression of a membrane flippase (ATP11A), and increased expression of a mucin (MUC1)—in critical disease. Mendelian randomization provides evidence in support of causal roles for myeloid cell adhesion molecules (SELE, ICAM5 and CD209) and the coagulation factor F8, all of which are potentially druggable targets. Our results are broadly consistent with a multi-component model of COVID-19 pathophysiology, in which at least two distinct mechanisms can predispose to life-threatening disease: failure to control viral replication; or an enhanced tendency towards pulmonary inflammation and intravascular coagulation. We show that comparison between cases of critical illness and population controls is highly efficient for the detection of therapeutically relevant mechanisms of disease

Hydrogeochemical Precursors of Strong Earthquakes:A Realistic Possibility in Kamchatka

The Kamchatka peninsula, located in the far East of Russia, is characterised by frequent and strong seismic activity (magnitudes up to 8.6). For many years, samples for hydrogeochemical analyses have been collected with a mean sampling frequency of three days in the form of the pH values and of the most common ions and gases in the groundwater of some deep wells and springs in the south area of the Kamchatka peninsula, where the capital city Petropavlovsk is located. In the last ten years, five earthquakes with M >6.5 have occurred at distances of less than 250 kin from the measurement sites. In order to reveal any possible precursors of these earthquakes, the hydrogeochemical data collected from three wells have been analysed. We have identified 12 anomalies with 8 of them being possible successes and 4 failures as earthquake precursors and we have obtained a probability of 67% that any given hydrogeochemical anomaly is an earthquake precursor. One of the results obtained indicates that the possibility of observing precursors in the hydrogeochemical parameters of a well seems to be related to the location of an earthquake with respect to the well. Recently, this behaviour was confirmed when we observed a clear co-post seismic effect in only one well after an earthquake on December 5, 1997, which was about 400 kin distant and very strong (M=7.7)

An ionospheric sounder for the Mars landers

International audienceThe planet Mars has been visited in the past by orbital probes and landers to study the atmosphere and the ground. But despite these numerous missions, more than 20 years ago, many parameters and phenomena are not known at this time. The large possibilities given by new technologies, in terms of weight and power consumption, allow the realization of new experiments at the surface of Mars. The aim is to propose the installation of a bottomside ionospheric sounder. This instrument will contribute to our scientific understanding of Mars. It will answer one of the main scientific objectives of the IMEWG (International Mars Exploration Working Group) mission scenario: the characterization of the Martian upper atmosphere and its interaction with the solar wind. Ionospheric sounding is a well-known technique at the surface of the Earth which has proven to be very useful for the study of the lower ionosphere. The principle is to transmit a radio pulse vertically and to measure the time which elapses before the echo is received. By varying the frequency of the pulse carrier wave, a plot can be obtained of echo delay versus frequency. It gives information about the propagation medium. The scientific objectives are described which can be achieved with such an experiment and the parameters which can be measured underlining the specificity of the Martian atmosphere are given. The theoretical scientific background of this sounder is briefly described and, finally, its feasibility is discussed

The effect of a foliar disease (rust) on the development of Gastrophysa viridula (Coleoptera: Chrysomelidae).

1. Gastrophysa viridula Degeer (Coleoptera: Chrysomelidae) and the pathogenic rust fungus Uromyces rumicis (Schum.) Wint. both occur on leaves of Rumex crispus L. and R.obtusifolius L. Individual stages of beetle development, and egg laying, were compared on healthy and infected leaves of each plant species in the laboratory. Oviposition choice was investigated in the field and laboratory. 2. Beetles reared on infected leaves of each species had greater larval mortality and slower development than those reared on healthy leaves. Although larvae feeding on infected leaves consumed up to 2.5 times more dry weight than those reared on healthy leaves, they had a lower relative growth rate and pupated at a lower weight. These changes were consistent with the reduced nutritive quality of rust-infected Rumex leaves. 3. Fecundity of beetles reared on infected leaves of both species was considerably reduced. Eggs laid by beetles feeding on infected R.crispus leaves also had a reduced viability. 4. The beetle developed consistently poorer on healthy R.crispus than on healthy R.obtusifolius throughout its life-cycle. Differences in larval performance were greater between host species than between infected and healthy leaves. 5. Oviposition was similar on infected and healthy R.crispus in both the laboratory and field. However, adults consumed less, and laid fewer eggs on infected than on healthy R.obtusifolius. The pattern of egg laying on different aged leaves was affected by rust infection: a greater proportion of eggs was laid on the older, infected leaves, than on the equivalent aged leaves on the healthy plants. Few larvae survived from eggs laid on rusted leaves in the field