228 research outputs found
Unusual decrease of the cosmic ray intensity in May 2019 on the background of the minima solar activity
In May 2019 there was a long and sloping decreasing of cosmic rayâs intensity (up to ~4%), which was observed
on neutron monitors. Despite this was a small decreasing compared to quasi-eleven-period variation, it stands
out well in 24th cycle of solar activity.
According to LASCO/SOHO and STEREO-A data from spectrometer in different UHF bands and from coronograph,
there was a series of CMEs which affected on modulation of cosmic rays by creating a series of Forbush decrea -
sing, which didnât restore. This series was connected to two active regions on sun and began on April 30 from
âreversed haloâ CME. This CME didnât reach the earth, but led to significant additional modulation of cosmic rays,
mostly on east side. Later there was a series of smaller CMEs on May 1-6, which also didnât reach the earth, but
were gradually approaching to Earth. Recent CMEs on 8-9 and 12-13 created a normal Forbush decreasing.
In May 2019, cosmic rays shown again, that they can collect information about distant objects of geliosphere and
transmit it to Earth. The ground-level detectors sometimes can observe an interaction of interplanetary distur-
bances, which didnât reach the earth. East CMEs are especially effective, because they closing magnetic field
lines beyond the orbit of earth and can interfere the restoring of cosmic rayâs intensity
Differentiation between <I>Yersinia pestis</I> Strains of Altaic-Hissar Group of Non-Main Subspecies by Means of PCR
On the basis of comparison between the genome-wide sequences of Altaic and Hissar strains of non-main subspecies and strains from Talas high-mountain plague focus, identified have been two novel DNA-targets, the usage of which provides for easy rapid subdivision of these closely-related strains of non-main subspecies that fall into separate phylogenetic brunches of plague agent evolution, applying PCR assay. One of the targets is allocated to intergenic region between YPO3333 and YPO3332 genes. In strains of altaica ssp. it contains 122 bps deletion. The other target is YPO2412 gene region which contains 72 bps deletion in Talas strains. Special primers for DNA-targets have been designed. Established have also been test specifications. Efficacy of the method for differentiation between the strains of Altaic-Hissar group of non-main subspecies is validated on 97 Y. pestis strains of various ssp
Relationship of the characteristics of large Forbush decreases and the heliolongitude of their sources
In this investigation the different features and characteristics of Forbush decreases, with emphasis on large For-
bush decreases (â„4%) and their association to solar sources, are being examined. According to the heliolongitude
of the solar source, the events under study were separated into three subcategories: western (21Âș †heliolongitude
†60Âș), eastern (-60Âș †heliolongitude †-21Âș) and central (-20Âș †heliolongitude †20Âș). The selected events cover
the time period 1967 - 2017. The âGlobal Survey Methodâ was used for analyzing the Forbush decreases, along with
data on solar flares, solar wind speed, geomagnetic indices (Kp and Dst), and interplanetary magnetic field. In ad -
dition, the superimposed epoch method was applied in order to plot the time profiles for the aforementioned group
of events. This detailed analysis reveals interesting results concerning the features of cosmic ray decreases in re-
gard to the heliolongitude of the solar sources. Moreover, it is also shown that large Forbush decreases, regardless
of the heliolongitude of the solar source, are accompanied by increased geomagnetic activity and increased aniso-
tropy, including anisotropy before the events, which can serve as a typical precursor of Forbush decreases
Snow effect on the neutron monitor network for 2018-2019
In this article, the influence of the surrounding snow cover on the neutron monitors count rate of the world network of neutron monitors was estimated using the method of reference stations. The applied technique also makes it possible to estimate the snow cover thickness at the observation point, which was done for more than two dozen stations. A comparison of the data correction results for snow is carried out for the case of automatic correction, based on the developed algorithm, and for manual one, with an error estimate
Gravitational Wave Bursts from Collisions of Primordial Black Holes in Clusters
The rate of gravitational wave bursts from the mergers of massive primordial
black holes in clusters is calculated. Such clusters of black holes can be
formed through phase transitions in the early Universe. The central black holes
in clusters can serve as the seeds of supermassive black holes in galactic
nuclei. The expected burst detection rate by the LISA gravitational wave
detector is estimated.Comment: 10 pages, 2 figure
The new Athens center on data processing from the neutron monitor network in real time
International audienceThe ground-based neutron monitors (NMs) record galactic and solar relativistic cosmic rays which can play a useful key role in space weather forecasting, as a result of their interaction with interplanetary disturbances. The Earth's-based neutron monitor network has been used in order to produce a real-time prediction of space weather phenomena. Therefore, the Athens Neutron Monitor Data Processing Center (ANMODAP) takes advantage of this unique multi-directional device to solve problems concerning the diagnosis and forecasting of space weather. At this moment there has been a multi-sided use of neutron monitors. On the one hand, a preliminary alert for ground level enhancements (GLEs) may be provided due to relativistic solar particles and can be registered around 20 to 30 min before the arrival of the main part of lower energy particles responsible for radiation hazard. To make a more reliable prognosis of these events, real time data from channels of lower energy particles and X-ray intensity from the GOES satellite are involved in the analysis. The other possibility is to search in real time for predictors of geomagnetic storms when they occur simultaneously with Forbush effects, using hourly, on-line accessible neutron monitor data from the worldwide network and applying a special method of processing. This chance of prognosis is only being elaborated and considered here as one of the possible uses of the Neutron Monitor Network for forecasting the arrival of interplanetary disturbance to the Earth. The achievements, the processes and the future results, are discussed in this work
Historical and Modern Classifications of the Plague Agent
The review presents the data on domestic and foreign phenotypic classifications of Yersinia pestis strains developed in the XX century; genetic classifications of the XXI century; as well as on the genealogy of ancient strains of the plague microbe, reconstructed using paleogenomic technologies. Since the discovery of the plague agent in 1894, many classifications were created that corresponded to the level of development of microbiology at that time. The intraspecific classification schemes of the XX century were based on three principles: phenotypic differences between strains, features of the species composition of carriers, and geographical affiliation. With the development of molecular microbiology early on in the XXI century, a genetic nomenclature of the branches of the pathogen evolution was developed and a number of classifications based on the analysis of the population structure of Y. pestis were created. Through the prism of the genetic diversity of Y. pestis strains from natural plague foci in Russia, near and far abroad countries, an improved classification with a division into seven subspecies has been developed: pestis, tibetica, caucasica, qinghaica, angolica, central asiatica, ulegeica, which allocates the subspecies according to the phylogenetic principle and epidemic significance. With the advancements in paleomicrobiology, prehistoric lineages of evolution have been included in the genealogy of Y. pestis, which expand the data on the intraspecific diversity of the plague microbe
Paleogenomics of the Plague Agent and Prospects for Paleogenomic Studies in Russia
The review contains information on paleogenomic studies of the plague pathogen, Yersinia pestis, covering the prehistoric epoch, the periods of the first and second plague pandemics, epidemics and outbreaks of plague of the late XIXâXX centuries. We have summarized the data on the reconstruction of ancient Y. pestis genomes of the Late Neolithic, Bronze and Iron Ages, the Justinian Plague epidemic of the first plague pandemic, the Black Death epidemic and the subsequent epidemics of the second plague pandemic of the XIVâXVIII centuries, as well as on tracing the pathways of plague propagation waves in Eurasia and the course of plague agent evolution with the formation of a vector-borne transmission route with the help of arthropods. We present the results of our own research of Y. pestis genomes from the key sites of formation of etiological agents of the first and second plague pandemics in the Tien Shan Mountains, historical outbreaks in the Northern and North-Western Caspian sea region and other regions of Russia and adjoining countries in the late XIXâXX centuries. The paper discusses the areas of the Caucasus, Crimea, Northern Caspian, Siberia, and Tien Shan in the territory of Russia and neighboring states that are promising for national paleogenomic studies of plague
Correlation effects during liquid infiltration into hydrophobic nanoporous mediums
Correlation effects arising during liquid infiltration into hydrophobic
porous medium are considered. On the basis of these effects a mechanism of
energy absorption at filling porous medium by nonwetting liquid is suggested.
In accordance with this mechanism, the absorption of mechanical energy is a
result expenditure of energy for the formation of menisci in the pores on the
shell of the infinite cluster and expenditure of energy for the formation of
liquid-porous medium interface in the pores belonging to the infinite cluster
of filled pores. It was found that in dependences on the porosity and,
consequently, in dependences on the number of filled pores neighbors, the
thermal effect of filling can be either positive or negative and the cycle of
infiltration-defiltration can be closed with full outflow of liquid. It can
occur under certain relation between percolation properties of porous medium
and the energy characteristics of the liquid-porous medium interface and the
liquid-gas interface. It is shown that a consecutive account of these
correlation effects and percolation properties of the pores space during
infiltration allow to describe all experimental data under discussion
Identification of Genovariants of Yersinia pestis Strains Belonging to Main Subspecies Using PCR with Hybridization-Fluorescent Registration of Results
For the first time ever developed has been the method of identification of genovariants in Yersinia pestis strains belonging to the main subspecies using PCR with hybridization-fluorescent registration of results. A complex of DNA-targets, the most of which are newly detected ones, have been utilized to differentiate between genovariants of antique (0.ANT, 1.ANT, 2.ANT, 4.ANT), medievalis (2.MED, 2.MED0), and orientalis (1.ORI) biovars. Application of these targets in PCR with hybridization-fluorescent registration of results provides for a rapid, effective and reliable classifying of the strains of the genovariants, circulating in various geographical regions. Efficacy of the method has been validated via analysis of 110 Y. pestis strains, isolated in the territory of the Russian Federation, neighboring countries and beyond, including 37 strains of antique, 53 strains of medievalis, and 20 strains of orientalis biovars
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