Assessing the potential spread and maintenance of foot-and-mouth disease virus infection in wild ungulates: general principles and application to a specific scenario in Thrace.

Foot-and-mouth disease (FMD), due to infection with serotype O virus, occurred in wild boar and within eleven outbreaks in domestic livestock in the south-east of Bulgaria, Thrace region, in 2011. Hence, the issue of the potential for the spread and maintenance of FMD virus (FMDV) infection in a population of wild ungulates became important. This assessment focused on the spread and maintenance of FMDV infection within a hypothetical wild boar and deer population in an environment, which is characterized by a climate transitional between Mediterranean and continental and variable wildlife population densities. The assessment was based on three aspects: (i) a systematic review of the literature focusing on experimental infection studies to identify the parameters describing the duration of FMDV infection in deer and wild boar, as well as observational studies assessing the occurrence of FMDV infection in wild deer and wild boar populations, (ii) prevalence survey data of wild boar and deer in Bulgaria and Turkey and (iii) an epidemiological model, simulating the host-to-host spread of FMDV infections. It is concluded, based on all three aspects, that the wildlife population in Thrace, and so wildlife populations in similar ecological settings, are probably not able to maintain FMD in the long term in the absence of FMDV infection in the domestic host population. However, limited spread of FMDV infection in time and space in the wildlife populations can occur. If there is a continued cross-over of FMDV between domestic and wildlife populations or a higher population density, virus circulation may be prolonged.

[Heart rhythm in humans with different processing levels of acoustic information].

The peculiarities of the heart rhythm regulation were investigated in humans during the processing of acoustic information. Statistically significant differences were found in individuals with different levels of auditory-motor reactions according to the heart rhythm characteristics. Individuals with the high level of reactions were characterized by significantly lower total power spectrum (TP=1276.2 ms2), by the power spectrum of high (HL=280.1 ms12) and very low frequencies (VLF-469.8 ms2), as well as by low indexes of standard deviation of R-R intervals (SDNN=37.4 ms), when compared with the persons with the low level of reactions (5248.8; 866.7; 1937.0; 69.8 ms2). The correlation analysis confirmed the dif- ferences between the groups ol persons with adtierent number of processed information and variable (r=0.41, P<0.05) and spectral characteristics of heart rate (r=-0.49--0.56, P<0.05). Different strategies of activation of non-specific brain systems in formation of psycho-physiological reactions and participation of heart rhythm regulatory mechanisms in vegetative support of auditory information processing are discussed.

The cold European winter of 2005-2006 assisted the spread and persistence of H5N1 influenza virus in wild birds.

In January 2006, a major cold spell affected Europe, coinciding with an increase of H5N1 influenza virus detected in wild birds, mostly dead mute swans, starting along the River Danube and the Mediterranean coast line. Subsequently H5N1 detections in wild birds were concentrated in central and western parts of Europe, reaching a peak in mid February. We tested the hypothesis that the geographic distribution of these H5N1 infections was modulated by the long-term wintering line, the 0 °C isotherm marking the limit beyond which areas are largely unsuitable for wintering waterfowl. Given the particularly cold 2005-2006 European winter, we also considered the satellite-derived contemporary frost conditions. This brought us to select the long-term maximum rather than the mean January 0 °C isotherm as the best approximation for the 2005-2006 wintering line. Our analysis shows that H5N1 detection sites were closer to the wintering line than would be expected by chance, even when the geographic distribution of water bird wintering sites was accounted for. We argue that partial frost conditions in water bodies are conducive to bird congregation, and this may have enhanced H5N1 transmission and local spread. Because the environmental virus load also would build up in these hot spots, H5N1 virus may have readily persisted during the spring, at least in cooler areas. We conclude that H5N1 introduction, spread, and persistence in Europe may have been enhanced by the cold 2005-2006 winter.

[Mutation variability and marker trait inheritance in hybrid-mutant populations F2M2 of winter wheat]. / Mutatsiina minlyvist' ta uspadkuvannia markernykh oznak u hibrydno-mutantnykh populiatsii F2M2 ozymoï m'iakoï pshenytsi.

Influence of hybrid seed treatment with mutagenes on genetic variability in hybrid populations of the second generation of winter wheat has been investigated. Treatment with mutagenes in moderate doses results in deviation of segregation of marker traits as compared to control towards either increase or decrease of the ratio of recessive allels. It was shown that in crossing combinations with red-ear form as one of the parental components, treatment with gamma rays at the dose of 100 Gy leads to significantly larger deviations of disintegration comparing to control.

[Autonomic support for mental activities of different degrees of complexity in younger school-age children]. / Vehetstyvne zabezpechennia rozumovoï diial'nosti riznoho stupenia slakdnosti u ditei molodshoho shkil'noho viku.

We have been studying peculiarities of vegetative provision of mental activity with different level of difficulty. It was revealed that efficiency of mental activity of children from junior school depends on the difficulty of the given visual information and vegetative provision. It was proved that children from junior school had the highest level of mental activity with easiest tasks, but vegetative provision was minimal. When the task became more difficult earning capacity of the brain was down but we saw more expressed change in vegetative provision. In case of the highest level of visual information presentations we saw the lowest level capability of the brain but reducing of vegetative provision. We discussed mechanisms of the links between working ability of the brain and vegetative provision of mental activity of different difficulty level.

[The functional dynamics of attention and its relation to the individual typological properties of the nervous system in middle-aged and elderly persons]. / Dynamika funktsiï uvahy ta ïï zv'iazok z indyvidual'no-typolohichnymy vlastyvostiamy nervovoi systemy u liudei zriloho ta pokhyloho viku.

The age dynamics of attention's function and its correlation with functional mobility of nervous processes at adults in age from 21 to 74 years old were studied. It was determined that this period of ontogenesis characterized gradual and irregular determination this function. It was revealed that mean exponents of attention's qualities and peculiarities its age dynamics depended from individual-typological properties of nervous system et adults and old men. The adults with high exponents of function mobility of nervous processes at all age groups have high level of development of attention's function and slower changing and delay of beginning of involution this mental function. The adults with low exponents of function mobility of nervous processes characterized earlier beginning and intensive deterioration of attention's function.

[Effect of bivalent copper ions on conformation of polyriboadenylic acid]. / Issledovanie vliianiia ionov dvukhvalentnoi medi na konformatsiiu poliriboadenilovoi kisloty.

Ultraviolet differential spectra (UDS) and CD-spectra of poly (A) in the presence of Cu2+ ions are studied at different degrees of phosphate groups screening. The binding of cu2+ ions with bases of phosphates is shown to lead to disordering or to ordering respectively, of the mutual orientation of nucleotides. The UDS components due to conformation variations in poly (A) and association between Cu2+ ions and its bases are calculated. Comparison of the latter UDS-component with the differential spectrum of a protonated adenosine-monophosphate permits to assume that Cu2+ ions are in a coordination bond with N (1) adenine. The calculation of the concentration dependence of the binding constants indicates binding cooperativity and weak dependence on the screening degree of poly (A) phosphate groups.

[Effect of magnesium ions on heat denaturation of DNA]. / Issledovanie deistviia ionov magniia na teplovuiu denaturatsiiu DNK.

The dependence of animal DNA denaturation on magnesium ion concentration has been studied in the range (10(-6)--10(-1) M with sodium ion content of 10(-3) and 10(-2) M. Special attention has been given to the effect of multivalent metallic impurities bound to DNA. An increase of DNA thermal stability has been shown to occur in the magnesium concentration rage of 10(-6)--10(-4) M. At concentrations exceeding 10(-3) M the T M begins to decrease. The dependence of the DNA melting range on magnesium ion concentration has a maximum at approximately 10(-5) M Mg2+. At low magnesium and sodium ion concentrations a strong asymmetry of the melting curves has been observed. This effect can be described in terms of the melting theory for DNA complexed with small molecules and is explained by magnesium ion redistribution from the denatured portions of DNA to native ones. The method for calculation of melting curves in the DNA-ligand system has been proposed. Studies of thermal denaturation parameters have been shown to be an effective method for the estimation of binding constants of ligands to native and denatured DNA.

[Melting of DNA-total histone complexes in the presence of noradrenaline]. / Plavlenie kompleksov DNK-summarnyi giston v prisutstvii noradrenalina.

Study is presented of the effect of noradrenaline on thermic denaturation of DNA-total histone complexes within the range of protein concentrations which corresponds to c1/c2 0-1.7 in solutions of 10(-3) M Na+ ionic strength (c1 and c2 being the weight concentrations of protein and nucleic acid, respectively). Denaturation of these systems has been found to be strongly affected by bivalent metals contained in DNA samples. Their presence accounts for the high temperature and wide melting range of DNA and diminution of the latter with an increase of the protein concentration in DNA-histone complexes. The denaturation parametres obtained for the studied systems are in fair agreement with predictions from the clip thermodynamic theory. Noradrenaline is shown to be capable of destabilizing DNA-total histon complexes. This is due to the inactivation of bivalent metals bound with DNA by noradrenaline. It is also suggested that noradrenaline does not weaken the histone binding with a nucleic acid.