Investigation of the angular distribution and energy spectrum of fast ions produced during irradiation of targets by short laser pulses in the SOKOL-P facility

Results are presented from experimental investigations of the angular distributions and energy spectra of fast ions produced in deuterium polyethylene targets under irradiation by picosecond laser pulses with intensities of up to 2 × 10¹⁸ W/cm² in the SOKOL-P facility. The parameters of ion fluxes were measured by time-of-flight spectrometers based on semiconductor detectors.     

Selection of strains of Streptomyces griseus Kr., the producer of a streptothricin antibiotic grisin, using the method of protoplast fusion

The effect of protoplasting on antibiotic activity of the grisin-producing organism was shown. High frequency of Grn- mutants after strain VG307f protoplasting and no capacity in these mutants for reversion to the initial Grn+ phenotype were shown. The reversion frequency was less than 10(-8). Moreover, it was shown that all the Grn- mutants lost their stability (GrnR) to the effect of their own antibiotic. With respect to strain VG212 there was noted a significant increase in the number of both the minus and the plus variants after the protoplast formation and regeneration. Fusing of protoplasts of strains VG307f and VG212 belonging to the divergent lines in selection of S. griseus Kr. yielded the phage stable strain VG7849 with high levels of the antibiotic production and improved technological properties.     

Efficiency of dolphin auditory perception in relation to time characteristics of the signal]

Experimental data are presented on evaluating the efficiency of auditory perception of the dolphin Tursiops truncatus of tonal signals of different duration and of the fixed energy on the background of Gauss obstacle. The dependence of percepting properties on time characteristics of the signal are stated. A comparative analysis of the efficiency of dolphin auditory system with that of the coordinated filter is carried out. Biological receiving systems are shown to be adaptive. The self-tuning linits of the dolphin auditory system at a given level of the possibility of correct detection are determined.     

Reaction of vessels of the microcirculatory bed of subcutaneous tissue to exposure to an argon laser beam

The effect of argon laser irradiation on the microvessels of the subcutaneous fat tissue of rabbit's ear placed into Clark's transparent chamber was studied. Capillaries and venules were found to be sensitive to argon laser irradiation; functional disturbances of microcirculation were most distinct. Following laser irradiation an active reconstruction of the microcirculatory bed with the redistribution of the blood stream took place along with destruction of the vascular wall and perivascular inflammation.     

Characteristics of tumors that have developed in mice injected with syngenic irradiated mesenchymal stem cells of bone marrow

Mesenchymal stem cells (MSCs) are found in virtually all organs and tissues. These cells can presumably be transformed into tumor stem cells by genotoxic factors and, subsequently, initiate tumor growth. The aim of the present work consisted in analysis of the possibility of malignant transformation of cultured MSCs from the bone marrow (BM) of mice after in vitro exposure to γ-radiation and in the characterization of biochemical and histological features of tumors that developed after the transplantation of BM MSCs to syngenic mice. Two of five mice developed tumors 3 to 4 months after the subcutaneous injection of BM MSCs irradiated at a dose of 1 Gy, five of five animals developed tumors after the administration of BM MSCs irradiated at a dose of 6 Gy, and only one of five mice injected with nonirradiated BM MSCs developed a tumor 6 months after cell transplantation. Telomerase activity in a tumor that developed from BM MSCs irradiated at a dose of 6 Gy was twice as high as that in the tumor that developed from BM MSCs irradiated at a dose of 1 Gy. The histological structure of the neoplasms corresponded to that of multicomponent mesenchymoma, a malignant tumor also termed “a mix of sarcomas.” The tumors consisted of tissue fragments of different histological types. Thus, BM MSCs exposed to 1 or 6 Gy of radiation can be transformed into tumor cells and give rise to multicomponent mesenchymomas, whereas malignant transformation of control BM MSCs occurs much less often.     

Review of water bugs of the genus Micronecta Kirk. (Heteroptera,Corixidae) of the fauna of the Northwestern Caucasus

A review of the species of the genus Micronecta from the Northwestern Caucasus with a key is provided. The regional distribution of Micronecta griseola Horváth, M. poweri (Douglas et Scott), and M. pusilla (Horváth) is clarified. Micronecta anatolica anatolica Lindberg is recorded from Russia for the first time.     

Characteristics of enterobacteria isolated from patients with urogenital pathology

Species composition and a number of persistence characteristics enterobacteria isolated from urine of 42 pregnant and 22 nonpregnant women with pyelonephritis (relapse, remission), from prostatic fluid of 225 males and secretions of cervical canal of 124 women with urogenital pathology (prostatitis, salpingo-oophoritis) were studied. The study revealed that enterobacteria, including Escherichia coli, prevailed in the structure of uromicroflora (66.7-83.3%) and constituted a relatively small proportion among "genital" isolates of microorganisms (19.9-22.2%). Male and female sterility and the presence of enterobacteria in the reproductive tract of patients were found to be directly correlated. Clinical isolates of enterobacteria were shown to possess pronounced seroresistance and the complex of persistence characteristics, including antilysozyme, anti-intercidal and anticomplementary activity.     

Genomic divergence of zebu and taurine cattle identified through high-density SNP genotyping

Background

Natural selection has molded evolution across all taxa. At an arguable date of around 330,000 years ago there were already at least two different types of cattle that became ancestors of nearly all modern cattle, the Bos taurus taurus more adapted to temperate climates and the tropically adapted Bos taurus indicus. After domestication, human selection exponentially intensified these differences. To better understand the genetic differences between these subspecies and detect genomic regions potentially under divergent selection, animals from the International Bovine HapMap Experiment were genotyped for over 770,000 SNP across the genome and compared using smoothed F_ST. The taurine sample was represented by ten breeds and the contrasting zebu cohort by three breeds.

Results

Each cattle group evidenced similar numbers of polymorphic markers well distributed across the genome. Principal components analyses and unsupervised clustering confirmed the well-characterized main division of domestic cattle. The top 1% smoothed F_ST, potentially associated to positive selection, contained 48 genomic regions across 17 chromosomes. Nearly half of the top F_ST signals (n = 22) were previously detected using a lower density SNP assay. Amongst the strongest signals were the BTA7:~50 Mb and BTA14:~25 Mb; both regions harboring candidate genes and different patterns of linkage disequilibrium that potentially represent intrinsic differences between cattle types. The bottom 1% of the smoothed F_ST values, potentially associated to balancing selection, included 24 regions across 13 chromosomes. These regions often overlap with copy number variants, including the highly variable region at BTA23:~24 Mb that harbors a large number of MHC genes. Under these regions, 318 unique Ensembl genes are annotated with a significant overrepresentation of immune related pathways.

Conclusions

Genomic regions that are potentially linked to purifying or balancing selection processes in domestic cattle were identified. These regions are of particular interest to understand the natural and human selective pressures to which these subspecies were exposed to and how the genetic background of these populations evolved in response to environmental challenges and human manipulation.

Electronic supplementary material

The online version of this article (doi:10.1186/1471-2164-14-876) contains supplementary material, which is available to authorized users.     

Assessing signatures of selection through variation in linkage disequilibrium between taurine and indicine cattle

Background

Signatures of selection are regions in the genome that have been preferentially increased in frequency and fixed in a population because of their functional importance in specific processes. These regions can be detected because of their lower genetic variability and specific regional linkage disequilibrium (LD) patterns.

Methods

By comparing the differences in regional LD variation between dairy and beef cattle types, and between indicine and taurine subspecies, we aim at finding signatures of selection for production and adaptation in cattle breeds. The VarLD method was applied to compare the LD variation in the autosomal genome between breeds, including Angus and Brown Swiss, representing taurine breeds, and Nelore and Gir, representing indicine breeds. Genomic regions containing the top 0.01 and 0.1 percentile of signals were characterized using the UMD3.1 Bos taurus genome assembly to identify genes in those regions and compared with previously reported selection signatures and regions with copy number variation.

Results

For all comparisons, the top 0.01 and 0.1 percentile included 26 and 165 signals and 17 and 125 genes, respectively, including TECRL, BT.23182 or FPPS, CAST, MYOM1, UVRAG and DNAJA1.

Conclusions

The VarLD method is a powerful tool to identify differences in linkage disequilibrium between cattle populations and putative signatures of selection with potential adaptive and productive importance.     

The effect of biologically active substances from coniferous plants on the L-phenylalanine ammonia lyase and peroxidase activities in wheat leaves

The effect of the preparations produced from needles and wood of various coniferous species on the activities of L-phenylalanine ammonia lyase (PAL; EC 4.3.1.5) and peroxidase (PO; EC 1.11.1.7), the enzymes involved in the development of plant defense response, was studied. It was demonstrated that treatment of soft wheat (Triticum aestivum L.) primary leaves with biological preparations produced from coniferous plants caused a transient increase in PAL and PO activities. The induction of these enzyme activities depends on the concentration of preparations and plant immune status. The results obtained suggest that coniferous metabolites are of interest as a source of plant extracts with the elicitor effect, increasing the resistance of plants to phytopathogens and adverse environmental factors.