118 research outputs found
Європейські правові стандарти становлення інформаційного суспільства
Ромащенко В. А. Європейські правові стандарти становлення інформаційного суспільства / В. А. Ромащенко // Правові та інституційні механізми забезпечення розвитку держави та права в умовах євроінтеграції : матеріали Міжнародної науково-практичної конференції (20 травня 2016 р., м. Одеса) : у 2 т. Т. 1 / відп. ред. М. В. Афанасьєва. - Одеса : Юридична література, 2016. - С. 370-372
Algorithmic statistics revisited
The mission of statistics is to provide adequate statistical hypotheses
(models) for observed data. But what is an "adequate" model? To answer this
question, one needs to use the notions of algorithmic information theory. It
turns out that for every data string one can naturally define
"stochasticity profile", a curve that represents a trade-off between complexity
of a model and its adequacy. This curve has four different equivalent
definitions in terms of (1)~randomness deficiency, (2)~minimal description
length, (3)~position in the lists of simple strings and (4)~Kolmogorov
complexity with decompression time bounded by busy beaver function. We present
a survey of the corresponding definitions and results relating them to each
other
Behavioral and neuronal responses of two mouse species, Mus musculus and Mus spicilegus, to con- and heterospecific olfactory signals
The behavioral and neuronal responses of the males of two closely related species of mice (Mus musculus wagneri, M. spicilegus) to the urine odors of estrus con- and heterospecific females were studied. In two-choice odor tests males significantly longer investigated odor of conspecific females in comparison with heterospecific ones. To investigate neuronal activation in the main and accessory olfactory bulbs (MOB and AOB), one of the methods of functional tomography – manganese-enhanced MRI ( ME-MRI) – was used. There was a significant increase in Mn2+ accumulation in the dorsal section of the posterior part of the MOB in male M. m. wagneri and M. spicilegus exposed to odor of conspecific females compared with the control group males (odor not exposed). There was a local significant increase in manganese accumulation in the dorsal region of the anterior part of the MOB in the case of the exposure of odor of a heterospecific female. The exposure of heptanone-2 to mice resulted not only in an increase in Mn2+ accumulation in certain zones, but also in a significant decrease in the accumulation of Mn2+ in the rest of the olfactory bulbs. A significant increase in the accumulation of MRI contrast in AOB was observed in males only in the case of female urine-conspecific odor exposure. The results support the previously stated assumption of a significant difference in chemical communication systems in two species of mice. A comparison of these results and results obtained previously demonstrated the absence of any differences in behavioral and neuronal responses to con- and heterospecific odors of the house mouse subspecies allopatric (M. m. wagneri) and sympatric (M. m. musculus) to M. spicilegus. This fact does not allow us to assume the effect of the mechanism of “reinforcement” in the process of evolution in the formation of precopulatory reproductive isolation between the sympatric species M. spicilegus and M. musculus
Ethnicity-specific distribution of <em>TRPM8</em> gene variants in Eurasian populations: signs of selection
The TRPM8 gene encodes the ion channel, which is a cold receptor in afferent neurons of the mammalian somatosensory system. We studied the frequency of haplotype distribution from six SNPs in the TRPM8 gene in Eurasian human populations, including Russians, Kazakhs and Chukchi. Four of the six SNPs are located in exon 7 (rs13004520, rs28901637, rs11562975, rs17868387), rs7593557 is in exon 11. These exons encode parts of the N-terminus, which is necessary for channel functioning in the plasma membrane of neurons. The rs11563071 is in exon 23 encoding part of the C-terminus. The primary difference in population distribution of haplotypes determines the SNP from exon 11 which leads to Ser419Asn substitution in protein. The most pronounced differences in the patterns of diversity and frequencies of haplotypes were observed between Chukchi and Russians. The frequency of major H1 haplotype encompassing the 419Ser gene variant differs in examined populations; 0.738 (Russians), 0.507 (Kazakhs) and 0.337 (Chukchi), p < 0.001. The TRPM8 gene variants encoding 419Asn and carrying the minor alleles of rs28901637 (P249P) and rs11562975 (L250L) in exon 7 are characteristic of Asian populations. The frequency of all 419Asn variants in Chukchi is comparable to that in Africans, however, the minor allele frequencies of rs28901637, rs11562975 in Africans is low. Apparently in the process of human colonization of Eurasia, minor alleles of these SNPs diverged depending on rs7593557 structure in exon 11. We analyzed sequences of five TRPM8 mRNA isoforms extracted by researchers from different tissues. Sequence analysis demonstrates that they are transcribed from major H1 variant of the TRPM8 gene but contain different translation start codons, which are generated by alternative splicing from pro-mRNA
Effect of physical activity on structural asymmetry of mouse hippocampus
The relevance of studies of adult neurogenesis is evident in connection with the potential use of these new neurons to replace neurons lost in the process of life. Despite considerable efforts, little is known about the fnal fate of these cells, the functional signifcance of their connections and the regulation of their development. It is known that physical activity signifcantly increases the number of fssile progenitors, the precursors of new neurons in the dentate gyrus of the hippocampus. The existing immunohistochemical methods for labeling new neurons do not allow tracing the temporal dynamics of changes in the volume of brain structures in the same animal, induced by external impacts, such as voluntary exercise. This makes it an urgent task to develop and improve methods for longterm control of changes that occur in the adult hippocampus due to the induction of neurogenesis. The main purpose of this work was to noninvasively track, by using magnetic resonance imaging (MRI), the temporal dynamics of changes in the volume of the hippocampus in the same animals that had voluntary physical activity. It was found that voluntary exercise did not change the total volume of the mouse hippocampus. However, the difference in the volume ratio between the right and left parts of the hippocampus was signifcantly lower compared with the control group. The reconstruction and analysis of proteinprotein interactions that ensure the survival of a large number of new neurons and their integration into existing neural networks in the hippocampus have been carried out. The proposed approach allows the noninvasive registration of changes in the ratio of the volumes of these paired brain structures
In vivo MRI visualization of growth and morphology in the orthotopic xenotrasplantation U87 glioblastoma mouse SCID model
Glioblastoma multiforme (GBM) is the most common and lethal type of brain cancer with the average lifespan of patients about 9–12 months. The study of tumor formation and the evaluation of new therapies for GBM require accurate and reproducible experimental brain tumor animal models. In this study we used MRI for investigation of tumor morphology and growth dynamic in an orthopic xenotransplantation immunodeficient mouse model (SCID mouse line). Comparison of T1- and T2-weighed MRI scans preformed with a high-field MRI scanner (Bruker, BioSpec, 11,7 T) revealed insufficient tumor/normal tissue T1-contrast because of high longitudinal magnetization of the magnetic field in our scanner. Intravenous injection of paramagnetic manganese oxide (MnO) nanoparticles dramatically increased the tumor/normal tissue contrast in T1-weigthed MRI scans. The study of glioblastoma growth with T2-weighed images showed that a significant tumor development began not earlier than 3 weeks after cell culture intracranial injection and then the tumor grew exponentially. Thus, we developed a protocol of the characterization of glioblastoma U87 growth and morphology by T1- and T2-weighed and MnO-enhanced MRI in the orthopic xenotransplantation mouse model. The results demonstrate that this SCID model may be used as an in vivo preclinical model to test the efficacy and putative side effects of novel anticancer therapies
DEVELOPMENT OF A METHODOLOGY FOR THE IMPACT OF ELECTROMAGNETIC INTERFERENCE ON THE FUNCTIONING OF ELECTRONIC DEVICES
The article describes a methodology for assessing the influence of electromagnetic inter-ference on the functioning of electronic devices. A block diagram of an algorithm for testing and processing the obtained experimental data is presented
Between-strain differences in hypothermic response in mice after intranasal administration of PtO nanoparticles
Air pollution by particulate matter (PM) has been associated with cardiopulmonary morbidity and mortality in many recent epidemiological studies. It has been shown that transition metal compounds, well- known toxic components of PM, are able to induce hypothermia following whole-body inhalation exposure. Low temperature appears to protect tissue against toxic effects of PM metal compounds in vivo and in vitro. To study the role of soluble and insoluble irritants in the induction of the hypothermic response, we analyzed the decrease in mouse body temperature (Δtbody) after intranasal administration of PtO nanoparticles or a K2[PtCl 4] solution. Between-strain differences in Δtbody after intranasal administration of the irritants were evaluated using 6 inbred (BALB/cJ, C57BL/6J, AKR/OlaHsd, DBA/2JRccHsd, C3H/HeNHsd, and SJL/J) and 2 outbred mouse strains (SCID and CD1). BALB/cJ and SCID mice showed the most pronounced effect of intranasal administration of the xenobiotic on tbody. Thus, tbody was significantly lower after nasal administration the PtO nanoparticles than after administration of the K2[PtCl 4] solution. To study the mechanism of this decrease, we compared the respective values for Δtbody following intranasal, intravenous and peroral administration of PtO nanoparticles in Balb/c mice. Neither intravenous nor peroral administration had any effect on mouse body temperature. This fact together with data on the dynamics of the decrease in mouse body temperature following intranasal administration of PtO nanoparticles (max Δtbody ~ 80–100 min) allowed us to assume that this process is under nervous regulation. The correlation found between our data and some well-known phenotypic characteristics (phenome.jax.org) of the mouse strains used confirms this hypothesis
Olfactory transport efficiency of the manganese oxide nanoparticles (II) after their single or multiple intranasal administrations
In experiments with reusable inhalation of nano-sized metal oxide particles, it has been shown that there is no significant relationship between the number of presentations and the metal concentration in the olfactory bulb. This fact raises the question of a possible decrease in the efficiency of particulate capturing by the olfactory epithelium after their repeated application into the nasal cavity. In this study, we compared the effectiveness of nasal transport of paramagnetic nanoparticles after their single and multiple intranasal administration and evaluated their effects on the morphological and functional characteristics of the olfactory system. Based on the data, the accumulation of MnO-NPs in the olfactory bulb of mice was reduced after repeated intranasal application. In addition, the decrease in the efficiency of olfactory transport observed after repeated administration of MnO-NPs was partially restored by intranasal application of mucolytic (0.01 M N-acetyl-L-cysteine). In this case, the concentration of particles in the olfactory bulb was proportional to the volume of the structure, which in particular depends on the number of synaptic contacts between the mitral cell of the olfactory bulb (OB) and olfactory epithelium (OE). It should be noted that multiple intranasal injections of MnO-NPs reduce mouse OE thickness. Thus, repeated intranasal introduction of MnO-NPs reduces the efficiency of nanoparticle olfactory transport from the nasal cavity to the brain, which is combined with the increase in the viscosity of the mucosal layer and the reduction in the number of synaptic contacts between OB and OE. These results indicate the presence of the natural mechanisms of protection against the penetration of pathogens and xenobiotics into the olfactory epithelium; they also allow us to formulate practical recommendations on intranasal drugs delivery
Learning-induced sensory plasticity of mouse olfactory epithelium
Traditionally, studies of the neurobiology of learning and memory focus on the circuitry that interfaces between sensory inputs and behavioral outputs, such as the amygdala and cerebellum. However, evidence is accumulating that some forms of learning can in fact drive stimulusspecifc changes very early in sensory systems, including not only primary sensory cortices but also precortical structures and even the peripheral sensory organs themselves. In this study, we investigated the effect of olfactory associative training on the functional activity of olfactory epithelium neurons in response to an indifferent stimulus (orange oil). It was found that such a peripheral structure of the olfactory system of adult mice as the olfactory epithelium (OE) demonstrates experiencedependent plasticity. In our experiment, associative learning led to changes in the patterns of OE cell activation in response to orange oil in comparison with the control group and animals that were given odor without reinforcement. To interpret the results obtained, we compared the distribution of MRI contrast across the zones of OE in response to a conditioned odor in trained animals and in control animals that were given orange oil at three concentrations: original (used for conditioning), 4fold higher and 4fold lower. Since the OE activation patterns obtained coincided in the group of trained animals and controls, which were stimulated with orange oil at the 4fold higher concentration, it can be concluded that associative conditioning increased the sensitivity of the OE to the conditioned stimulus. The observed increase in OE response to orange oil may be the result of neurogenesis, i. e. the maturation of new olfactory neurons responsive to this stimulus, or the consequence of an increase in individual sensitivity of each OE neuron. Based on data of MRI contrast accumulation in mouse OE, the sensory plasticity way in learninginduced increase in sensitivity of OE to conditioned stimulus is more possible. Thus, the sensory plasticity of the OE plays a signifcant role in the formation of the neuronal response to the provision of an initially indifferent odor and is part of the adaptive responses to the environmental changing
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