Electrical conductivity of plasmas of DB white dwarf atmospheres

The static electrical conductivity of non-ideal, dense, partially ionized helium plasma was calculated over a wide range of plasma parameters: temperatures $1\cdot 10^{4}\textrm{K} \lesssim T \lesssim 1\cdot 10^{5}\textrm{K}$ and mass density $1 \times 10^{-6} \textrm{g}/\textrm{cm}^{3} \lesssim \rho \lesssim 2 \textrm{g}/\textrm{cm}^{3}$. Calculations of electrical conductivity of plasma for the considered range of plasma parameters are of interest for DB white dwarf atmospheres with effective temperatures $1\cdot 10^{4}\textrm{K} \lesssim T_{eff} \lesssim 3\cdot 10^{4}\textrm{K}$. Electrical conductivity of plasma was calculated by using the modified random phase approximation and semiclassical method, adapted for the case of dense, partially ionized plasma. The results were compared with the unique existing experimental data, including the results related to the region of dense plasmas. In spite of low accuracy of the experimental data, the existing agreement with them indicates that results obtained in this paper are correct

Path Integral Monte Carlo and Density Functional Molecular Dynamics Simulations of Hot, Dense Helium

Two first-principles simulation techniques, path integral Monte Carlo (PIMC) and density functional molecular dynamics (DFT-MD), are applied to study hot, dense helium in the density-temperature range of 0.387 - 5.35 g/cc and 500 K - 1.28x10^8 K. One coherent equation of state (EOS) is derived by combining DFT-MD data at lower temperatures with PIMC results at higher temperatures. Good agreement between both techniques is found in an intermediate temperature range. For the highest temperatures, the PIMC results converge to the Debye-Hueckel limiting law. In order derive the entropy, a thermodynamically consistent free energy fit is introduced that reproduces the internal energies and pressure derived from the first-principles simulations. The equation of state is presented in form of a table as well as a fit and is compared with chemical models. In addition, the structure of the fluid is analyzed using pair correlation functions. Shock Hugoniot curves are compared with recent laser shock wave experiments.Comment: 16 pages, 15 figure

Diversitatea agenţilor cauzali ai bolilor infecţioase identificată în populaţia căpuşelor colectate în Republica Moldova

Summary. The diversity of causative agents of infectious diseases identified in ticks collected in the Republic of Moldova. Arthropod ticks (family Ixodidae) are vectors for pathogens that cause infectious diseases in humans. Species collected in the Republic of Moldova and identified as: Ixodes ricinus, Dermacentor reticulatus, D. marginatus and Haemophysalis punctata were subjected of laboratory research methods: enzyme-linked immunoassay (ELISA) and polymerase chain reaction (PCR). The results showed that in the ixodidae tick populations were identified genomes of causative agents of the next transmissible diseases: Tick-born encephalitis, West Nile, Lyme disease, Ehrlihioses, and Babesiosis.Pезюме. Разновидность возбудителей инфекционных заболеваний в популяции клещей, собранных на территории Республики Молдова. Иксодовые клещи являются переносчиками ряда инфекционных заболеваний у людей. Виды, собранные на территории Республики Молдова и идентифицированные как: Ixodes ricinus, Dermacentor reticulatus, D. marginatus и Haemophysalis punctata были исследованы используя следующие лабораторные методы: иммуноферментный анализ (ИФА) и полимеразная цепная реакция (ПЦР). Результаты показали, что в клещах были определены геномы возбудителей следующих инфекционных болезней: клещевого энцефалита, лихорадки Западного Нила, Лайм-боррелиоза, эрлихиоза и бабезиоза

Experimental infection of H5N1 HPAI in BALB/c mice

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Dense plasmas in astrophysics: from giant planets to neutron stars

We briefly examine the properties of dense plasmas characteristic of the interior of giant planets and the atmospheres of neutron stars. Special attention is devoted to the equation of state of hydrogen and helium at high density and to the effect of magnetic fields on the properties of dense matter.Comment: Invited Review, Strongly Coupled Coulomb Systems, Moscow June 2005; to appear in Journal of Physics

Phase Transition in Strongly Degenerate Hydrogen Plasma

Direct fermionic path-integral Monte-Carlo simulations of strongly coupled hydrogen are presented. Our results show evidence for the hypothetical plasma phase transition. Its most remarkable manifestation is the appearance of metallic droplets which are predicted to be crucial for the electrical conductivity allowing to explain the rapid increase observed in recent shock compression measurments.Comment: 1 LaTeX file using jetpl.cls (included), 5 ps figures. Manuscript submitted to JETP Letter

Peculiarities of directions and causal agents’ distribution of tick-borne encephalitis in the Republic of Moldova

The aim of the study is to determine the circulation of tick-borne encephalitis (TBE) causal agents in the Ixodidae ticks population and the evaluation of the TBE threat to public health. The species of ticks Ixodes ricinus, Dermacentor reticulatus, D. marginatus and Haemaphysalis punctata can be often met in the ecosystems of the Republic of Moldova. The species I. ricinus is the most numerous and widespread one, the fact that shows its high epidemiological significance. At the same time the species D. reticulatus, D. marginatus and H. punctata are the potential directions of TBE maintaining the TBE viruses in the environment. The laboratory results got by the enzyme-linked immunosorbent assay (ELISA) have indicated the TBE virus antigen in of 25.2% of the ticks, collected in the period of 2009-2012. Using the polymerase chain reaction method it has been established that on average the RNA of TBE virus has been 8.1% of all tested tick samples. The specific antibodies to tick-borne encephalitis virus have been identified in 9 (4%) tested human specimens. The rationalization of the system of epidemiological surveillance and control of tick-born encephalitis consists in developing and implementing a definition of the case for report on the basis of clinical and laboratory criteria, as well as the communication with epidemiological station, and studying to obtain standardized and comparable data

Dual Programmed Cell Death Pathways Induced by p53 Transactivation Overcome Resistance to Oncolytic Adenovirus in Human Osteosarcoma Cells

Tumor suppressor p53 is a multifunctional transcription factor that regulates diverse cell fates, including apoptosis and autophagy in tumor biology. p53 overexpression enhances the antitumor activity of oncolytic adenoviruses; however, the molecular mechanism of this occurrence remains unclear. We previously developed a tumor-specific replication-competent oncolytic adenovirus, OBP-301, that kills human osteosarcoma cells, but some human osteosarcoma cells were OBP-301-resistant. In this study, we investigated the antitumor activity of a p53-expressing oncolytic adenovirus, OBP-702, and the molecular mechanism of the p53-mediated cell death pathway in OBP-301-resistant human osteosarcoma cells. The cytopathic activity of OBP-702 was examined in OBP-301-sensitive (U2OS and HOS) and OBP-301-resistant (SaOS-2 and MNNG/HOS) human osteosarcoma cells. The molecular mechanism in the OBP-702-mediated induction of two cell death pathways, apoptosis and autophagy, was investigated in OBP-301-resistant osteosarcoma cells. The antitumor effect of OBP-702 was further assessed using an orthotopic OBP-301-resistant MNNG/HOS osteosarcoma xenograft tumor model. OBP-702 suppressed the viability of OBP-301-sensitive and -resistant osteosarcoma cells more efficiently than OBP-301 or a replication-deficient p53-expressing adenovirus (Ad-p53). OBP-702 induced more profound apoptosis and autophagy when compared with OBP-301 or Ad-p53. E1A-mediated miR-93/106b upregulation induced p21 suppression, leading to p53-mediated apoptosis and autophagy in OBP-702-infected cells. p53 overexpression enhanced adenovirus-mediated autophagy through activation of damage-regulated autophagy modulator (DRAM). Moreover, OBP-702 suppressed tumor growth in an orthotopic OBP-301-resistant MNNG/HOS xenograft tumor model. These results suggest that OBP-702-mediated p53 transactivation is a promising antitumor strategy to induce dual apoptotic and autophagic cell death pathways via regulation of miRNA and DRAM in human osteosarcoma cells. Mol Cancer Ther; 12(3); 314-25