289 research outputs found

    Higher education in the field of natural sciences as innovative business success

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    It is suggested in the article qualities that should have any chief to successfully engage in innovative enterpriseВысказываются предположения о том, какими качествами должен быть наделен руководитель, чтобы успешно заниматься инновационным предпринимательство

    Analysis of the goldfish Carassius auratus olfactory epithelium transcriptome reveals the presence of numerous non-olfactory GPCR and putative receptors for progestin pheromones

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    The goldfish (Carassius auratus) uses steroids and prostaglandins as pheromone cues at different stages of the reproductive cycle to facilitate spawning synchronization. Steroid progestin pheromone binding has been detected in goldfish olfactory membranes but the receptors responsible for this specific binding remain unknown. In order to shed some light on the olfactory epithelium transcriptome and search for possible receptor candidates a large set of EST from this tissue were analysed and compared to and combined with a similar zebrafish (Danio rerio) resource

    Economic potential and development prospects of small businesses in rural areas

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    The article examines the role of small business in the development of rural areas by the example of bakery production. Moreover, it demonstrates the need for the interaction of small bakery businesses with large enterprises of the industry and grain processors. The article reveals the development trends of small bakery production in rural areas. The conditions for the participation of small bakery businesses in rural areas in the development of the production of functional and specialized bread are substantiated. The article proposes the directions and mechanisms of support for small bakery production at the level of rural territories. The development of modern methods of redistribution of bakery production in proportion to the living population, measures of state support for small bakery production and expansion of the range of bread products that contribute to improving the health of the population of Russia, is the theme of this study. The object of the research is the development of small bakery production as a condition for improving the quality of life of the population in rural areas. The subject of the research is production and management relations that ensure the development of small bakery production and its impact on the quality of life of the population in rural areas.peer-reviewe

    Experiments on wave turbulence : the evolution and growth of second sound acoustic turbulence in superfluid 4He confirm self-similarity.

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    We report our experiments on the formation of second sound acoustic turbulence in superfluid 4He. The initial growth in spectral amplitude follows power laws that steepen rapidly with increasing harmonic number n, corresponding to a propagating front in frequency space. The lower growth exponents agree well with analytic predictions and numerical modeling. The observed increase in the formation delay with n validates the concept of selfsimilarity in the growth of wave turbulence

    Effect of acute copper sulfate exposure on olfactory responses to amino acids and pheromones in goldfish (Carassius auratus)

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    Exposure of olfactory epithelium to environmentally relevant concentrations of copper disrupts olfaction in fish. To examine the dynamics of recovery at both functional and morphological levels after acute copper exposure, unilateral exposure of goldfish olfactory epithelia to 100 μM CuSO4 (10 min) was followed by electro-olfactogram (EOG) recording and scanning electron microscopy. Sensitivity to amino acids (L-arginine and L-serine), generally considered food-related odorants, recovered most rapidly (three days), followed by that to catecholamines(3-O-methoxytyramine),bileacids(taurolithocholic acid) and the steroid pheromone, 17,20 -dihydroxy-4-pregnen- 3-one 20-sulfate, which took 28 days to reach full recovery. Sensitivity to the postovulatory pheromone prostaglandin F2R had not fully recovered even at 28 days. These changes in sensitivity were correlated with changes in the recovery of ciliated and microvillous receptor cell types. Microvillous cells appeared largely unaffected by CuSO4 treatment. Cilia in ciliated receptor neurones, however, appeared damaged one day post-treatment and were virtually absent after three days but had begun to recover after 14 days. Together, these results support the hypothesis that microvillous receptor neurones detect amino acids whereas ciliated receptor neurones were not functional and are responsible for detection of social stimuli (bile acidsandpheromones).Furthermore, differences in sensitivity to copper may be due to different transduction pathways in the different cell types

    Parametric generation of second sound in superfluid helium: linear stability and nonlinear dynamics

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    We report the experimental studies of a parametric excitation of a second sound (SS) by a first sound (FS) in a superfluid helium in a resonance cavity. The results on several topics in this system are presented: (i) The linear properties of the instability, namely, the threshold, its temperature and geometrical dependencies, and the spectra of SS just above the onset were measured. They were found to be in a good quantitative agreement with the theory. (ii) It was shown that the mechanism of SS amplitude saturation is due to the nonlinear attenuation of SS via three wave interactions between the SS waves. Strong low frequency amplitude fluctuations of SS above the threshold were observed. The spectra of these fluctuations had a universal shape with exponentially decaying tails. Furthermore, the spectral width grew continuously with the FS amplitude. The role of three and four wave interactions are discussed with respect to the nonlinear SS behavior. The first evidence of Gaussian statistics of the wave amplitudes for the parametrically generated wave ensemble was obtained. (iii) The experiments on simultaneous pumping of the FS and independent SS waves revealed new effects. Below the instability threshold, the SS phase conjugation as a result of three-wave interactions between the FS and SS waves was observed. Above the threshold two new effects were found: a giant amplification of the SS wave intensity and strong resonance oscillations of the SS wave amplitude as a function of the FS amplitude. Qualitative explanations of these effects are suggested.Comment: 73 pages, 23 figures. to appear in Phys. Rev. B, July 1 st (2001
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