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Akademgorodok, Russia

Cyplik P.,University of Life Sciences in Poznan | Schmidt M.,University of Life Sciences in Poznan | Szulc A.,Poznan University of Technology | Marecik R.,University of Life Sciences in Poznan | And 5 more authors.
Bioresource Technology | Year: 2011

The degradation of diesel fuel, B20 blend and biodiesel in liquid cultures by a seven-member bacterial consortium was compared under conditions with full aeration or with limited aeration with nitrate added as main electron acceptor. Community dynamics was assessed employing real-time PCR and the ddCt method for relative quantification. Biodegradation rates increased with increasing biodiesel content, but were significantly reduced under conditions with nitrate. Despite large variations in biodegradation rates, magnitude changes in population numbers were typically observed only from zero to one order, regardless the type of fuel and electron acceptor. Only Comamonadaceae and Variovorax sp. distinctly preferred aerobic conditions, and during aerobic growth showed suppression as fuel contained more biodiesel. Thus, the consortium is relatively stable and most of the degraders can shift their metabolism from hydrocarbons to biodiesel. The stability of the consortium is of interest in the context of biodiesel-mediated biodegradation of petroleum hydrocarbons. © 2010 Elsevier Ltd. Source

Bailey M.A.,University of Edinburgh | Craigie E.,University of Edinburgh | Livingstone D.E.W.,University of Edinburgh | Kotelevtsev Y.V.,University of Edinburgh | And 4 more authors.
Hypertension | Year: 2011

Salt sensitivity of blood pressure is an independent risk factor for cardiovascular morbidity. Mechanistically, abnormal mineralocorticoid action and subclinical renal impairment may blunt the natriuretic response to high sodium intake, causing blood pressure to rise. 11β-Hydroxysteroid dehydrogenase type 2 (11βHSD2) controls ligand access to the mineralocorticoid receptor, and ablation of the enzyme causes severe hypertension. Polymorphisms in HSD11B2 are associated with salt sensitivity of blood pressure in normotensives. In this study, we used mice heterozygote for a null mutation in Hsd11b2 (Hsd11b2) to define the mechanisms linking reduced enzyme activity to salt sensitivity of blood pressure. A high-sodium diet caused a rapid and sustained increase in blood pressure in Hsd11b2 mice but not in wild-type littermates. During the adaptation to high-sodium diet, heterozygotes displayed impaired sodium excretion, a transient positive sodium balance, and hypokalemia. After 21 days of high-sodium feeding, Hsd11b2 mice had an increased heart weight. Mineralocorticoid receptor antagonism partially prevented the increase in heart weight but not the increase in blood pressure. Glucocorticoid receptor antagonism prevented the rise in blood pressure. In Hsd11b2 mice, high-sodium feeding caused suppression of aldosterone and a moderate but sustained increase in corticosterone. This study demonstrates an inverse relationship among 11βHSD2 activity, heart weight, and blood pressure in a clinically important context. Reduced activity causes salt sensitivity of blood pressure, but this does not reflect illicit activation of mineralocorticoid receptors by glucocorticoids. Instead, we have identified a novel interaction among 11βHSD2, dietary salt, and circulating glucocorticoids. © 2011 American Heart Association, Inc. Source

Malov I.F.,RAS Lebedev Physical Institute | Nikitina E.B.,Pushchino State University
Astronomy Reports | Year: 2011

Data on the pulse structure and variations of the linear polarization angle at frequencies near 1 GHz have been used to estimate the angles β between the rotational axis and magnetic moment of the neutron stars assocaited with 80 pulsars. The calculations applied several methods. The minimum values of β were estimated from the observed pulse width W10 at the 10% level for the entire sample. Maximum estimates of β were obtained for six sources with small polarization position angle derivatives. Equations for the angle β were derived for various forms of the observed profile, and solutions obtained for 34 pulsars. The β values calculated using different methods are compared. For three pulsars with known interpulses, the obtained values of β demonstrate that two (PSR B1055-52 and PSR 1822-09) are aligned rotators, whereas the other (PSR B1702-19) is an orthogonal rotator. A search for interpulses and interpulse emission in PSRB1641-45, PSR1642-03, and PSR 1944+17 is necessary, and a search for an interpulse at 180° from the main pulse is required in PSR B2321-61. © 2011 Pleiades Publishing, Ltd. Source

Malov I.F.,RAS Lebedev Physical Institute | Nikitina E.B.,Pushchino State University
Astronomy Reports | Year: 2011

Data on the profiles and polarization of the 10- and 20-cm emission of radio pulsars are used to calculate the angle β between the rotational axis of the neutron star and its magnetic moment. It is shown that, for these calculations, it is sufficient to use catalog values of the pulse width at the 10% level W10, since the broadening of the observed pulses due to the transition to the full width W0 and narrowing of the pulses associated with the emission of radiation along tangents to the field lines approximately cancel each other out. The angles β1 are calculated for 283 pulsars at 20 cm and 132 pulsars at 10 cm, assuming that the line of sight passes through the center of the emission cone. The mean values of these angles are small and similar for the two wavelengths (〈β1〉=18° at λ=10 cm and 〈β1〉=14° at λ=20cm). The angle β2 is estimated for several dozen pulsars for the case when the orientation of the angle to the line of sight is arbitrary. The mean value of β2 at 10 cm is found to be 〈β2〉 = 33.9° if the maximum derivative of the polarization position angle C is positive and 〈β2〉 = 52.1° if C < 0. We find at 20 cm 〈β2〉=33.9° if C > 0 and 〈β2〉=54.1° if C < 0. The values at the two wavelengths are equal within the errors, and close to the β2 value obtained earlier at 30 cm (〈β2〉=36.4° if C > 0 and 〈β2〉=49.1° if C < 0). The mean 〈β2〉 for the entire set of data can be taken to be 43.5°. The period dependence of the pulse width W(P) ∝ P-0.25 differs from the relation that is usually used in the polar-cap model, W(P) ∝ P-0.5. This difference could be associated with the rate of development of plasma instabilities near the surface of the neutron star (in the region where high-frequency radiation is generated). The role of the quadrupole component of the magnetic field is not important here. There is no dependence of the angle β on the pulsar age (z distance, luminosity L, or characteristic age τ=P/(2dP/dt)) for the studied sample. © 2011 Pleiades Publishing, Ltd. Source

Lathe R.,RAS Shemyakin Ovchinnikov Institute of Bioorganic Chemistry | Sapronova A.,Pushchino State University | Kotelevtsev Y.,Queens Medical Research Institute
BMC Geriatrics | Year: 2014

Background: Aging is accompanied by increasing vulnerability to pathologies such as atherosclerosis (ATH) and Alzheimer disease (AD). Are these different pathologies, or different presentations with a similar underlying pathoetiology?. Discussion. Both ATH and AD involve inflammation, macrophage infiltration, and occlusion of the vasculature. Allelic variants in common genes including APOE predispose to both diseases. In both there is strong evidence of disease association with viral and bacterial pathogens including herpes simplex and Chlamydophila. Furthermore, ablation of components of the immune system (or of bone marrow-derived macrophages alone) in animal models restricts disease development in both cases, arguing that both are accentuated by inflammatory/immune pathways. We discuss that amyloid β, a distinguishing feature of AD, also plays a key role in ATH. Several drugs, at least in mouse models, are effective in preventing the development of both ATH and AD. Given similar age-dependence, genetic underpinnings, involvement of the vasculature, association with infection, Aβ involvement, the central role of macrophages, and drug overlap, we conclude that the two conditions reflect different manifestations of a common pathoetiology. Mechanism. Infection and inflammation selectively induce the expression of cholesterol 25-hydroxylase (CH25H). Acutely, the production of 'immunosterol' 25-hydroxycholesterol (25OHC) defends against enveloped viruses. We present evidence that chronic macrophage CH25H upregulation leads to catalyzed esterification of sterols via 25OHC-driven allosteric activation of ACAT (acyl-CoA cholesterol acyltransferase/SOAT), intracellular accumulation of cholesteryl esters and lipid droplets, vascular occlusion, and overt disease. Summary. We postulate that AD and ATH are both caused by chronic immunologic challenge that induces CH25H expression and protection against particular infectious agents, but at the expense of longer-term pathology. © 2014 Lathe et al.; licensee BioMed Central Ltd. Source

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