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Search Results: 1 - 10 of 5869 matches for " Igor Ponomarev "
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Chronic self-administration of alcohol results in elevated ΔFosB: comparison of hybrid mice with distinct drinking patterns
Ozburn Angela R,Mayfield R D,Ponomarev Igor,Jones Theresa A
BMC Neuroscience , 2012, DOI: 10.1186/1471-2202-13-130
Abstract: Background The inability to reduce or regulate alcohol intake is a hallmark symptom for alcohol use disorders. Research on novel behavioral and genetic models of experience-induced changes in drinking will further our knowledge on alcohol use disorders. Distinct alcohol self-administration behaviors were previously observed when comparing two F1 hybrid strains of mice: C57BL/6J x NZB/B1NJ (BxN) show reduced alcohol preference after experience with high concentrations of alcohol and periods of abstinence while C57BL/6J x FVB/NJ (BxF) show sustained alcohol preference. These phenotypes are interesting because these hybrids demonstrate the occurrence of genetic additivity (BxN) and overdominance (BxF) in ethanol intake in an experience dependent manner. Specifically, BxF exhibit sustained alcohol preference and BxN exhibit reduced alcohol preference after experience with high ethanol concentrations; however, experience with low ethanol concentrations produce sustained alcohol preference for both hybrids. In the present study, we tested the hypothesis that these phenotypes are represented by differential production of the inducible transcription factor, ΔFosB, in reward, aversion, and stress related brain regions. Results Changes in neuronal plasticity (as measured by ΔFosB levels) were experience dependent, as well as brain region and genotype specific, further supporting that neuronal circuitry underlies motivational aspects of ethanol consumption. BxN mice exhibiting reduced alcohol preference had lower ΔFosB levels in the Edinger-Westphal nucleus than mice exhibiting sustained alcohol preference, and increased ΔFosB levels in central medial amygdala as compared with control mice. BxN mice showing sustained alcohol preference exhibited higher ΔFosB levels in the ventral tegmental area, Edinger-Westphal nucleus, and amygdala (central and lateral divisions). Moreover, in BxN mice ΔFosB levels in the Edinger-Westphal nucleus and ventral tegmental regions significantly positively correlated with ethanol preference and intake. Additionally, hierarchical clustering analysis revealed that many ethanol-na ve mice with overall low ΔFosB levels are in a cluster, whereas many mice displaying sustained alcohol preference with overall high ΔFosB levels are in a cluster together. Conclusions By comparing and contrasting two alcohol phenotypes, this study demonstrates that the reward- and stress-related circuits (including the Edinger-Westphal nucleus, ventral tegmental area, amygdala) undergo significant plasticity that manifests as reduced alcohol preference
Gene Expression in Brain and Liver Produced by Three Different Regimens of Alcohol Consumption in Mice: Comparison with Immune Activation
Elizabeth Osterndorff-Kahanek, Igor Ponomarev, Yuri A. Blednov, R. Adron Harris
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0059870
Abstract: Chronically available alcohol escalates drinking in mice and a single injection of the immune activator lipopolysaccharide can mimic this effect and result in a persistent increase in alcohol consumption. We hypothesized that chronic alcohol drinking and lipopolysaccharide injections will produce some similar molecular changes that play a role in regulation of alcohol intake. We investigated the molecular mechanisms of chronic alcohol consumption or lipopolysaccharide insult by gene expression profiling in prefrontal cortex and liver of C57BL/6J mice. We identified similar patterns of transcriptional changes among four groups of animals, three consuming alcohol (vs water) in different consumption tests and one injected with lipopolysaccharide (vs. vehicle). The three tests of alcohol consumption are the continuous chronic two bottle choice (Chronic), two bottle choice available every other day (Chronic Intermittent) and limited access to one bottle of ethanol (Drinking in the Dark). Gene expression changes were more numerous and marked in liver than in prefrontal cortex for the alcohol treatments and similar in the two tissues for lipopolysaccharide. Many of the changes were unique to each treatment, but there was significant overlap in prefrontal cortex for Chronic-Chronic Intermittent and for Chronic Intermittent-lipopolysaccharide and in liver all pairs showed overlap. In silico cell-type analysis indicated that lipopolysaccharide had strongest effects on brain microglia and liver Kupffer cells. Pathway analysis detected a prefrontal cortex-based dopamine-related (PPP1R1B, DRD1, DRD2, FOSB, PDNY) network that was highly over-represented in the Chronic Intermittent group, with several genes from the network being also regulated in the Chronic and lipopolysaccharide (but not Drinking in the Dark) groups. Liver showed a CYP and GST centered metabolic network shared in part by all four treatments. We demonstrate common consequences of chronic alcohol consumption and immune activation in both liver and brain and show distinct genomic consequences of different types of alcohol consumption.
Reduction-Based Robustness Analysis of Linear Predictor Feedback for Distributed Input Delays
Anton Ponomarev
Mathematics , 2015, DOI: 10.1109/TAC.2015.2437520
Abstract: Lyapunov-Krasovskii approach is applied to parameter- and delay-robustness analysis of the feedback suggested by Manitius and Olbrot for a linear time-invariant system with distributed input delay. A functional is designed based on Artstein's system reduction technique. It depends on the norms of the reduction-transformed plant state and original actuator state. The functional is used to prove that the feedback is stabilizing when there is a slight mismatch in the system matrices and delay values between the plant and controller.
Neuroadaptations in Human Chronic Alcoholics: Dysregulation of the NF-κB System
Anna ?kvist, Sofia Johansson, Alexander Kuzmin, Igor Bazov, Roxana Merino-Martinez, Igor Ponomarev, R. Dayne Mayfield, R. Adron Harris, Donna Sheedy, Therese Garrick, Clive Harper, Yasmin L. Hurd, Lars Terenius, Tomas J. Ekstr?m, Georgy Bakalkin, Tatjana Yakovleva
PLOS ONE , 2007, DOI: 10.1371/journal.pone.0000930
Abstract: Background Alcohol dependence and associated cognitive impairments apparently result from neuroadaptations to chronic alcohol consumption involving changes in expression of multiple genes. Here we investigated whether transcription factors of Nuclear Factor-kappaB (NF-κB) family, controlling neuronal plasticity and neurodegeneration, are involved in these adaptations in human chronic alcoholics. Methods and Findings Analysis of DNA-binding of NF-κB (p65/p50 heterodimer) and the p50 homodimer as well as NF-κB proteins and mRNAs was performed in postmortem human brain samples from 15 chronic alcoholics and 15 control subjects. The prefrontal cortex involved in alcohol dependence and cognition was analyzed and the motor cortex was studied for comparison. The p50 homodimer was identified as dominant κB binding factor in analyzed tissues. NF-κB and p50 homodimer DNA-binding was downregulated, levels of p65 (RELA) mRNA were attenuated, and the stoichiometry of p65/p50 proteins and respective mRNAs was altered in the prefrontal cortex of alcoholics. Comparison of a number of p50 homodimer/NF-κB target DNA sites, κB elements in 479 genes, down- or upregulated in alcoholics demonstrated that genes with κB elements were generally upregulated in alcoholics. No significant differences between alcoholics and controls were observed in the motor cortex. Conclusions We suggest that cycles of alcohol intoxication/withdrawal, which may initially activate NF-κB, when repeated over years downregulate RELA expression and NF-κB and p50 homodimer DNA-binding. Downregulation of the dominant p50 homodimer, a potent inhibitor of gene transcription apparently resulted in derepression of κB regulated genes. Alterations in expression of p50 homodimer/NF-κB regulated genes may contribute to neuroplastic adaptation underlying alcoholism.
Microscopic analysis of a correlation between dipole transitions $1^-_1 \to 0^+_{g.s.}$ and $3^-_1 \to 2^+_{1}$ in spherical nuclei
V. Yu. Ponomarev
Physics , 1999,
Abstract: Correlation between B($E1, 1^-_1 \to 0^+_{g.s.}$) and B($E1, 3^-_1 \to 2^+_{1}$) values are considered within microscopic QRPA approach. General arguments for a dependence of a ratio between these values on a collectivity of the $2^+_1$ and $3^-_1$ phonons and ground state correlations are provided.
On "the authentic damping mechanism" of the phonon damping model
V. Yu. Ponomarev
Physics , 2002, DOI: 10.1103/PhysRevC.67.029801
Abstract: Some general features of the phonon damping model are presented. It is concluded that the fits performed within this model have no physical content.
On "the authentic damping mechanism" of the phonon damping model. II
V. Yu. Ponomarev
Physics , 2002,
Abstract: This article continues a discussion raised in previous publications (LANL preprint server, nucl-th/0202006 and nucl-th/0202020). I try to convince my opponents that general arguments are not "my case" and may be applied to their model.
Magnetic and Magnetoelectric Properties of Rare Earth Molybdates
B. K. Ponomarev,A. Zhukov
Physics Research International , 2012, DOI: 10.1155/2012/276348
Abstract: We present results on ferroelectric, magnetic, magneto-optical properties and magnetoelectric effect of rare earth molybdates (gadolinium molybdate, GMO, and terbium molybdate, TMO, and samarium molybdate, SMO), belonging to a new type of ferroelectrics predicted by Levanyuk and Sannikov. While cooling the tetragonal β-phase becomes unstable with respect to two degenerate modes of lattice vibrations. The β-β′ transition is induced by this instability. The spontaneous polarization appears as a by-product of the lattice transformation. The electric order in TMO is of antiferroelectric type. Ferroelectric and ferroelastic GMO and TMO at room temperature are paramagnets. At low temperatures GMO and TMO are antiferromagnetic with the Neel temperatures N=0.3 K (GMO) and N=0.45 K (TMO). TMO shows the spontaneous destruction at 40 kOe magnetic field. Temperature and field dependences of the magnetization in TMO are well described by the magnetism theory of singlets at 4.2 K ≤ T ≤ 30 K. The magnetoelectric effect in SMO, GMO and TMO, the anisotropy of magnetoelectric effect in TMO at T = (1.8–4.2) K, the Zeeman effect in TMO, the inversion of the electric polarization induced by the laser beam are discussed. The correlation between the magnetic moment of rare earth ion and the magnetoelectric effect value is predicted. The giant fluctuations of the acoustic resonance peak intensity near the Curie point are observed.
Functional status assessment of adolescents with different forms of influence for performed offences
Polovnikova А.А.,Ponomarev S.B.
Saratov Journal of Medical Scientific Research , 2010,
Abstract: The purpose of the study was to compare the functional status of adolescents, depending on the measure of impact of the offense. The data received indicated lower functional status of convicted adolescents, especially those with para-suicide behavior. Adolescents who were used humane methods of punishment for committed offenses demonstrated changes in the cardiovascular and respiratory systems only in the form of significant increase of stress index, while other parameters remained normal. The role of physical exercise in the correction of violations was under the study
Magnetic and Magnetoelectric Properties of Rare Earth Molybdates
B. K. Ponomarev,A. Zhukov
Physics Research International , 2012, DOI: 10.1155/2012/276348
Abstract: We present results on ferroelectric, magnetic, magneto-optical properties and magnetoelectric effect of rare earth molybdates (gadolinium molybdate, GMO, and terbium molybdate, TMO, and samarium molybdate, SMO), belonging to a new type of ferroelectrics predicted by Levanyuk and Sannikov. While cooling the tetragonal β-phase becomes unstable with respect to two degenerate modes of lattice vibrations. The β-β′ transition is induced by this instability. The spontaneous polarization appears as a by-product of the lattice transformation. The electric order in TMO is of antiferroelectric type. Ferroelectric and ferroelastic GMO and TMO at room temperature are paramagnets. At low temperatures GMO and TMO are antiferromagnetic with the Neel temperatures ?K (GMO) and ?K (TMO). TMO shows the spontaneous destruction at 40?kOe magnetic field. Temperature and field dependences of the magnetization in TMO are well described by the magnetism theory of singlets at 4.2?K ≤ T ≤ 30?K. The magnetoelectric effect in SMO, GMO and TMO, the anisotropy of magnetoelectric effect in TMO at T = (1.8–4.2)?K, the Zeeman effect in TMO, the inversion of the electric polarization induced by the laser beam are discussed. The correlation between the magnetic moment of rare earth ion and the magnetoelectric effect value is predicted. The giant fluctuations of the acoustic resonance peak intensity near the Curie point are observed. 1. Introduction At the end of 1960s, there was a great interest in the rare earth molybdates family (RMO) ( and ) because these compounds exhibited the phenomena of ferroelectricity and ferroelasticity [1]. RMO from (PMO) to TMO crystallizes to the tetragonal -structure with a space group P (point symmetry group is ). Their melting points are 1045°C for PMO and 1172°C for TMO. (DMO) crystallizes to cubic γ-phase at 1222°C and transforms to -structure at 1030°C. While cooling the family undergoes a transformation from the tetragonal -phase to the monoclinic -Phase. The temperatures of the - transformation are 987°C for PMO and 805°C for DMO. However, the transformation is sluggish and, therefore, the high-temperature phase can be quenched in. If the thermodynamically metastable -phases of RMO are further cooled, they undergo the second transformation leading to the lower symmetry ferroelastic-ferroelectric orthorhombic Pba2?? -structures (point symmetry group mm2). They are also thermodynamically metastable. The temperatures of - phase transitions are 235°C for PMO and 145°C for DMO. The single crystal samples of RMO are transparent in the visible light. Both
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