Universal profile of the vortex condensate in two-dimensional turbulence

An inverse turbulent cascade in a restricted two-dimensional periodic domain creates a condensate—a pair of coherent system-size vortices. We perform extensive numerical simulations of this system and carry out theoretical analysis based on momentum and energy exchanges between the turbulence and the vortices. We show that the vortices have a universal internal structure independent of the type of small-scale dissipation, small-scale forcing, and boundary conditions. The theory predicts not only the vortex inner region profile, but also the amplitude, which both perfectly agree with the numerical data

Effect of electric field on the photoluminescence of polymer-inorganic nanoparticles composites

We report on the effect of electric field on the photoluminescence, PL, from a composite consisting of a conjugated polymer mixed with zinc oxide nanoparticles. We have found that in the absence of electric field PL emission from the composite film has two maxima in the blue and green-yellow regions. Application of a voltage bias to planar gold electrodes suppresses the green-yellow emission and shifts the only PL emission maximum towards the blue region. Current-voltage characteristics of the polymer-nanoparticles composite exhibit the non-linear behavior typical of non-homogeneous polymer-inorganic structures. Generation of excited states in the composite structure implies the presence of several radiative recombination mechanisms including formation of polymer-nanoparticle complexes including exciplex states and charge transfer between the polymer and nanoparticle that can be controlled by an electric field.Comment: 5 pages, 5 figures. accepted for publication in Solid State Communication

A glycoprotein subunit vaccine elicits a strong Rift Valley fever virus neutralizing antibody response in sheep

Rift Valley fever virus (RVFV), a member of the Bunyaviridae family, is a mosquito-borne zoonotic pathogen that causes serious morbidity and mortality in livestock and humans. The recent spread of the virus beyond its traditional endemic boundaries in Africa to the Arabian Peninsula coupled with the presence of susceptible vectors in non-endemic countries has created increased interest in RVF vaccines. Subunit vaccines composed of specific virus proteins expressed in eukaryotic or prokaryotic expression systems are shown to elicit neutralizing antibodies in susceptible hosts. RVFV structural proteins, N-terminus glycoprotein (Gn) and C-terminus glycoprotein (Gc), were expressed using a recombinant baculovirus expression system. The recombinant proteins were reconstituted as GnGc subunit vaccine formulation and evaluated for immunogenicity in a target species, sheep. Six sheep were each immunized with a primary dose of 50 μg of each vaccine immunogen adjuvanted with montanide ISA25, and at day 21 post-vaccination, each animal received a second dose of the same vaccine. The vaccine induced strong antibody response in all animals as determined by indirect enzyme-linked immunosorbent assay (ELISA). Plaque reduction neutralization test (PRNT80) showed the primary dose of the vaccine was sufficient to elicit potentially protective virus neutralizing antibody titers ranging from 40 to 160, and the second vaccine dose boosted the titer to more than 1,280. Further, all animals tested positive for neutralizing antibodies at day 328 pv. ELISA analysis using the recombinant nucleocapsid protein as a negative marker antigen indicated that the vaccine candidate is DIVA (differentiating infected from vaccinated animals) compatible, and represents a promising vaccine platform for RVFV infection in susceptible species

Krupnomasshtabnye izmeneniya atlanticheskikh vod v Arkticheskom Basseine (Large-scale and interannual variability of the Atlantic water in the Arctic Ocean, in Russian)

The long-term variability of the intermediate Atlantic Water (AW) layer in the Arctic Ocean is analyzed. We reveal a positive temperature and negative salinity linear trends for the entire Arctic Ocean. Warming and cooling tendencies in the Canada Basin lags those for the Eurasian Basin by 9-10 years with similar duration for the warming and cooling periods for both basins. In contrast, salinity tendency in the Canada Basin lags those in the Eurasian Basins by 8-16 years salinity, and durationof saltier and fresher anomalies is different. The interannual variability for the depth of AW upper boundary and AW core temperature is studiedusing two first modes of the Empirical Orthogonal Function (EOF) decomposition exhibit unique patterns that have been never observed over the entire period of instrumental observations. For 2009, our analysis reveals the AW recovery to already observed patterns. our examination also shows that the AW warming and cooling is also accompanied by changes in depthsof the AW upper boundary and the AW core that provides evidence for the different volume and properties of the AW during warmer and cooler phases. In this respect, the AW warming in 1950s, 1990s differs from those in during the International Polar Year 2007/200

Novel long-chain neurotoxins from Bungarus candidus distinguish the two binding sites in muscle-type nicotinic acetylcholine receptors

αδ-Bungarotoxins, a novel group of long-chain α-neurotoxins, manifest different affinity to two agonist/competitive antagonist binding sites of muscle-type nicotinic acetylcholine receptors (nAChRs), being more active at the interface of α–δ subunits. Three isoforms (αδ-BgTx-1–3) were identified in Malayan Krait (Bungarus candidus) from Thailand by genomic DNA analysis; two of them (αδ-BgTx-1 and 2) were isolated from its venom. The toxins comprise 73 amino acid residues and 5 disulfide bridges, being homologous to α-bungarotoxin (α-BgTx), a classical blocker of muscle-type and neuronal α7, α8, and α9α10 nAChRs. The toxicity of αδ-BgTx-1 (LD50 = 0.17–0.28 µg/g mouse, i.p. injection) is essentially as high as that of α-BgTx. In the chick biventer cervicis nerve–muscle preparation, αδ-BgTx-1 completely abolished acetylcholine response, but in contrast with the block by α-BgTx, acetylcholine response was fully reversible by washing. αδ-BgTxs, similar to α-BgTx, bind with high affinity to α7 and muscle-type nAChRs. However, the major difference of αδ-BgTxs from α-BgTx and other naturally occurring α-neurotoxins is that αδ-BgTxs discriminate the two binding sites in the Torpedo californica and mouse muscle nAChRs showing up to two orders of magnitude higher affinity for the α–δ site as compared with α–ε or α–γ binding site interfaces. Molecular modeling and analysis of the literature provided possible explanations for these differences in binding mode; one of the probable reasons being the lower content of positively charged residues in αδ-BgTxs. Thus, αδ-BgTxs are new tools for studies on nAChRs

Clinically relevant morphological structures in breast cancer represent transcriptionally distinct tumor cell populations with varied degrees of epithelial-mesenchymal transition and CD44+CD24- stemness

Intratumor morphological heterogeneity in breast cancer is represented by different morphological structures (tubular, alveolar, solid, trabecular, and discrete) and contributes to poor prognosis; however, the mechanisms involved remain unclear. In this study, we performed 3D imaging, laser microdissection-assisted array comparative genomic hybridization and gene expression microarray analysis of different morphological structures and examined their association with the standard immunohistochemistry scorings and CD44+CD24- cancer stem cells. We found that the intratumor morphological heterogeneity is not associated with chromosomal aberrations. By contrast, morphological structures were characterized by specific gene expression profiles and signaling pathways and significantly differed in progesterone receptor and Ki-67 expression. Most importantly, we observed significant differences between structures in the number of expressed genes of the epithelial and mesenchymal phenotypes and the association with cancer invasion pathways. Tubular (tube-shaped) and alveolar (spheroid-shaped) structures were transcriptionally similar and demonstrated co-expression of epithelial and mesenchymal markers. Solid (large shapeless) structures retained epithelial features but demonstrated an increase in mesenchymal traits and collective cell migration hallmarks. Mesenchymal genes and cancer invasion pathways, as well as Ki-67 expression, were enriched in trabecular (one/two rows of tumor cells) and discrete groups (single cells and/or arrangements of 2-5 cells). Surprisingly, the number of CD44+CD24- cells was found to be the lowest in discrete groups and the highest in alveolar and solid structures. Overall, our findings indicate the association of intratumor morphological heterogeneity in breast cancer with the epithelial-mesenchymal transition and CD44+CD24- stemness and the appeal of this heterogeneity as a model for the study of cancer invasion

Collection and processing of environmental information in oil and gas production areas and solving other applied problems using active search methods (Review article)

The methods of monitoring the environmental situation as well as the problems of solving related applied environmental and resource problems in hard-to-reach areas of oil and gas production and also in other sectors of the national economy using unmanned aerial vehicles, are investigated. The methods of studying the types and thicknesses of the layers of the underlying surface by probing them with electromagnetic pulses of the radiofrequency range and gamma radiation are considered. Based on the existing theoretical dependencies of the interaction of electromagnetic radiation with the Earth’s surface, diagrams of the passage of electromagnetic waves in the decimeter and centimeter ranges through various landscape structures (snow-ice-water-frozen soil) are presented. It is shown that the use of gamma radiation makes it possible to solve the problem of determining the effective altitude of an aircraft during environmental monitoring due to the high energy of photon radiation and albedo from various surfaces including snow cover. A method for calculating the pollutant content on the underlying surface with a given probability of its reliable detection is presented. It is noted that the reliability of the readings of measuring instruments is significantly influenced by their geometric location on the transport platform. It is shown that the proposed solution is advisable to implement using two unmanned aerial vehicles or as mall-sized unmanned airship. Based on the review, the composition of the technical means of the complex for recognizing the types and thicknesses of layers of contamination of the underlying surface is proposed. A possible methodology for assessing the environmental situation is presented. The results of the work can be used in conducting environmental exploration of infrastructure used for transporting oil and gas resources in conditions of difficult access to it as well as for solving similar military-applied and engineering-construction tasks. At the same time, for the first time, the joint use of the radio frequency range of electromagnetic waves and gamma radiation was proposed. The radio frequency range makes it possible to study the structure of the landscape, and gamma radiation from backscattered ionizing radiation is a type of pollutant, as well as to ensure high accuracy in measuring the distance from the module to the upper layer of the underlying surface

Karyotype of the blastocoel fluid demonstrates low concordance with both trophectoderm and inner cell mass

Objective To compare the genomic profiles of blastocoel fluid (BF), inner cell mass (ICM), and trophectoderm (TE) cells derived from the same blastocyst. Design Prospective study. Setting Academic and in vitro fertilization units. Patient(s) Sixteen donated cryopreserved embryos at blastocyst stage. Intervention(s) BF, TE, and ICM cells were retrieved from each blastocyst for chromosome analysis by means of next-generation sequencing (NGS). Main Outcome Measure(s) Aneuploidy screening and assessment of mosaicism in BF, TE and ICM samples with subsequent comparison of genomic profiles between the three blastocyst compartments. Result(s) Out of 16 blastocysts, 10 BF samples and 14 TE and ICM samples provided reliable NGS data for comprehensive chromosome analysis. Only 40.0% of BF-DNA karyotypes were fully concordant with TE or ICM, compared with 85.7% concordance between TE and ICM. In addition, BF-DNA was burdened with mosaic aneuploidies and the total number of affected chromosomes in BF was significantly higher compared with the TE and ICM. Conclusion(s) BF-DNA can be successfully amplified and subjected to NGS, but owing to increased discordance with ICM and TE, BF does not adequately represent the status of the rest of the embryo. To overcome biologic and technical challenges associated with BF sampling and processing, blastocentesis would require improvement in both laboratory protocols and aneuploidy calling algorithms. Therefore, TE biopsy remains the most effective way to predict embryonic karyotype, and the use of BF as a single source of DNA for preimplantation genetic screening is not yet advised

Nonmonotonic Decay of Nonequilibrium Polariton Condensate in Direct-Gap Semiconductors

Time evolution of a nonequilibrium polariton condensate has been studied in the framework of a microscopic approach. It has been shown that due to polariton-polariton scattering a significant condensate depletion takes place in a comparatively short time interval. The condensate decay occurs in the form of multiple echo signals. Distribution-function dynamics of noncondensate polaritons have been investigated. It has been shown that at the initial stage of evolution the distribution function has the form of a bell. Then oscillations arise in the contour of the distribution function, which further transform into small chaotic ripples. The appearance of a short-wavelength wing of the distribution function has been demonstrated. We have pointed out the enhancement and then partial extinction of the sharp extra peak arising within the time interval characterized by small values of polariton condensate density and its relatively slow changes.Comment: 20 pages, LaTeX 2.09; in press in PR