A regime shift in the Sun-Climate connection with the end of the Medieval Climate Anomaly.

Understanding the influence of changes in solar activity on Earth's climate and distinguishing it from other forcings, such as volcanic activity, remains a major challenge for palaeoclimatology. This problem is best approached by investigating how these variables influenced past climate conditions as recorded in high precision paleoclimate archives. In particular, determining if the climate system response to these forcings changes through time is critical. Here we use the Wiener-Granger causality approach along with well-established cross-correlation analysis to investigate the causal relationship between solar activity, volcanic forcing, and climate as reflected in well-established Intertropical Convergence Zone (ITCZ) rainfall proxy records from Yok Balum Cave, southern Belize. Our analysis reveals a consistent influence of volcanic activity on regional Central American climate over the last two millennia. However, the coupling between solar variability and local climate varied with time, with a regime shift around 1000-1300 CE after which the solar-climate coupling weakened considerably.

[The results of patients questioning regarding dental implantation procedures].

Dental implantation is a widespread method of oral rehabilitation by teeth loss. The purpose of the study was to evaluate patients need and awareness of dental implantation. 486 respondents were included in survey. The low level of knowledge about dental implantation was identified among patients in Saratov.

[Application of physical therapeutic techniques for the improvement of the efficacy of dental implantation].

This study included 230 patients presenting with defects of tooth alignments. It has demonstrated that the physiotherapeutic treatment before and after dental implantation using a KAP-Parodontolog stomatological system markedly improved the outcome of implantation.

A generalization of the van-der-Pol oscillator underlies active signal amplification in Drosophila hearing.

The antennal hearing organs of the fruit fly Drosophila melanogaster boost their sensitivity by an active mechanical process that, analogous to the cochlear amplifier of vertebrates, resides in the motility of mechanosensory cells. This process nonlinearly improves the sensitivity of hearing and occasionally gives rise to self-sustained oscillations in the absence of sound. Time series analysis of self-sustained oscillations now unveils that the underlying dynamical system is well described by a generalization of the van-der-Pol oscillator. From the dynamic equations, the underlying amplification dynamics can explicitly be derived. According to the model, oscillations emerge from a combination of negative damping, which reflects active amplification, and a nonlinear restoring force that dictates the amplitude of the oscillations. Hence, active amplification in fly hearing seems to rely on the negative damping mechanism initially proposed for the cochlear amplifier of vertebrates.

Estimation of coupling between oscillators from short time series via phase dynamics modeling: limitations and application to EEG data.

We demonstrate in numerical experiments that estimators of strength and directionality of coupling between oscillators based on modeling of their phase dynamics [D. A. Smirnov and B. P. Bezruchko, Phys. Rev. E 68, 046209 (2003)] are widely applicable. Namely, although the expressions for the estimators and their confidence bands are derived for linear uncoupled oscillators under the influence of independent sources of Gaussian white noise, they turn out to allow reliable characterization of coupling from relatively short time series for different properties of noise, significant phase nonlinearity of the oscillators, and nonvanishing coupling between them. We apply the estimators to analyze a two-channel human intracranial epileptic electroencephalogram (EEG) recording with the purpose of epileptic focus localization.

[Polysaccharides of Ganoderma lucidum: factors affecting their production].

The conditions of polysaccharide production by the fungus Ganoderma lucidum were optimized. The maximal yield of endopolysaccharides and exopolysaccharides was observed at 25-30 degrees C, initial pH of culture medium 4.0-6.0, and at a C : N ratio of approximately 18 : 1 and 25 : 1, respectively. The greatest yield of mycelium was reached at a more intensive aeration, and the maximal yield of polysaccharides was observed at a less intensive aeration. The optimal ratio between fungus growth and polysaccharide production was observed at 100 rpm and an aeration of 1.0-1.5 1/1 medium min.

Preconditioning of the small intestine to ischemia in rats.

Measures reflecting the state of the small intestine were studied in rats after ischemia lasting 90 min produced by clamping the superior mesenteric artery and reperfusion for 30 min. Preconditioning of the intestine to ischemia was induced by producing intestinal ischemia for 10 min followed by 10 min of reperfusion (ischemic preconditioning), 30-min limb ischemia with 15-min reperfusion (distant ischemic preconditioning), and i.v. L-arginine. The smallest amount of damage to the intestine after 90 min of ischemia and 30 min of reperfusion was seen in the group of rats subjected to ischemic preconditioning. The protective effect of ischemic preconditioning was partially blocked by administration of N-omega-nitro-L-arginine (a blocker of NO synthesis). Doses of L-arginine also had protective effects, though these were smaller than those of ischemic preconditioning. Preliminary ischemia-reperfusion of the limb had no effect on the state of the intestine. Thus: 1) ischemic preconditioning of the intestine is partially associated with activation of nitric oxide synthesis, and 2) distant ischemic preconditioning did not protect the intestine.

Role of transient processes for reconstruction of model equations from time series.

We perform a global reconstruction of differential and difference equations, which model an object in a wide domain of a phase space, from a time series. The efficiency of using time realizations of transient processes for this purpose is demonstrated. Time series of transients are shown to have some advantages for the realization of a procedure of model structure optimization.

Coup-TFII is up-regulated in adenovirus type 12 tumorigenic cells and is a repressor of MHC class I transcription.

Down-regulation of the MHC class I enhancer in tumorigenic Ad12 cells is associated with strong binding of COUP-TF and negligible binding of activator NF-kappaB. By comparison, in nontumorigenic Ad5 cells, class I expression is high due to negligible binding of COUP-TF and strong binding of NF-kappaB. Here, we show that COUP-TFII, but not COUP-TFI, is expressed in Ad12-transformed cells. The dramatically stronger DNA binding of COUP-TFII to the class I enhancer in Ad12- compared to Ad5-transformed cells correlates with higher COUP-TFII promoter activity and higher levels of COUP-TFII mRNA and protein. Significantly, NF-kappaB p50/p52 double-knockout cells enabled us to demonstrate directly that COUP-TFII can completely repress both nonactivated and NF-kappaB-activated MHC class I transcription.

Constructing nonautonomous differential equations from experimental time series.

An approach to constructing model differential equations of harmonically driven systems is proposed. It is a modification of the standard global reconstruction technique: an algebraic polynomial which coefficients depend on time is used for approximation. Efficiency and details of the approach are demonstrated by various numerical and natural examples.

[Adaptation of the rat small intestine to ischemia]. / Adaptatsiia tonkoi kishki krys k ishemii.

Pre-conditioned rats underwent one cycle of intestinal ischemia/reperfusion with subsequent assessment of the heart remote ischemic pre-conditioning (IPC). A local IPC exerted an obvious protective action whereas a remote IPC was ineffective. The local IPC depended partially on the nitric oxide (NO) synthesis. L-arginine administration reduced the intestinal injury. The findings suggest that the ischemic pre-conditioning of intestine depends partially on the NO synthesis and that the remote IPC in intestine does not exist.

Association of histone deacetylase with COUP-TF in tumorigenic Ad12-transformed cells and its potential role in shut-off of MHC class I transcription.

Chicken ovalbumin upstream promoter-transcription factor (COUP-TF) is an orphan nuclear receptor that represses transcription of many genes. In adenovirus type 12 (Ad12) transformed cells, a high level of binding activity of COUP-TF to the major histocompatibility complex (MHC) class I enhancer correlates with the down-regulation of class I transcription, which, in turn, contributes to tumorigenesis. The mechanism by which COUP-TF represses transcription has yet to be elucidated. Here we show that COUP-TF represses transcription through its association with histone deacetylase. This was demonstrated using reciprocal binding assays that determined that the interaction between COUP-TF and histone deacetylase requires the COUP-TF C-terminal repression domain. Moreover, a histone deacetylase enzymatic activity was found to be associated with COUP-TF in Ad12-transformed cells. Transfection experiments further revealed that exogenous histone deacetylase facilitates transcriptional repression by COUP-TF. Also, supershift assays suggest that the transcriptional corepressor N-CoR, which is known to associate with histone deacetylases, is a part of the COUP-TF complex bound to the MHC class I enhancer R2 site. Finally, we provide evidence that inhibition of histone deacetylases relieves the repression of MHC class I expression in Ad12-transformed cells. Taken together these results support the notion that deacetylation of histones, mediated through COUP-TF, serves to down-regulate MHC class I transcription in Ad12-transformed cells.

[Acute pancreatitis and biological antioxidants]. / Ostryi pankreatit i bioantioksidanty.

The values of lipid free--radical oxidation and the effect of various methods of treatment on these processes were studied in 164 patients with acute pancreatitis. Combined use of oil emulsions with agents possessing antioxidation activity (unithiol, tocopherol) produced the best values. Combined therapy promoted normalization of the main parameters characterizing the activity of lipid peroxidation reactions which was attended with reduced concentrations of pancreatic enzymes and increased concentration of beta-lipoproteins in the blood. This was indicative of stabilization of the pancreatic cell membrane systems.

[Diagnosis and treatment of acute pancreatitis]. / Diagnostika i lechenie ostrogo pankreatita.

From study of 549 patients with various forms of acute pancreatitis (AP) the authors conclude that membrane disorders occur in these patients, in which case membrane modulators, products of lipid peroxidation (PLO) among others, play an inducing role. In addition to the routine clinical data, of great significance for the diagnosis of AP are laboratory findings on lactate dehydrogenase, alanine aminotransferase, aspartate aminotransferase, endogenous enzymes, transamidinase, concentrations of free kinins, blood coagulative system, study of free radical oxidation of lipids, beta-lipoprotein levels, etc. The authors recommend a wider use of fatty emulsions with heparin and intraarterial infusion of agents in the generally accepted complex of therapeutic measures. Operative treatment is usually indicated in approximately 20% of cases.

[Retrosternal novocaine blockade in the treatment of severe forms of bronchial asthma and status asthmaticus]. / Zagrudinnaia novokainovaia blokada v lechenii tiazhelykh form bronkhial'noi astmy i asmaticheskogo statusa.

Retrosternal procaine blockade with a 0.25% procaine solution, using a bent needle, 15-18 cm long, at the moment of bronchial asthma attack made it possible to arrest the attack in 25 patients, in 6 cases a considerable improvement of the patients' conditions was observed and in 4 patients there was no therapeutic effect. Retrosternal administration of 80-120 ml of a 0.25% procaine solution promotes to the improvement of respiration parameters, hemodynamics, blood gas composition. The procedure is simple and low traumatic.

[Diagnosis of membrane disorders in acute pancreatitis]. / Diagnostika membrannykh narushenii pri ostrom pankreatite.

In 110 patients with acute pancreatitis the authors studied the activity of intracellular enzymes in the blood (LDH, CPC, ALaT, ASaT, transamidinase) in a complex with indices characterizing the condition of the membrane cell systems, in particular: activity of acid phosphatase, content of 17-ketosteroids, activity of plasma chemiluminescence, concentration of beta-lipoproteins in blood. Complex study of these indices makes it possible to make a sufficiently objective judgement of the severity of the membrane disorders in acute pancreatitis and verity the form and control the treatment of the disease.

[A clinical case of botulism]. / Klinicheskoe nabliudenie botulizma.

A patient with botulism (type E) has been subject to complex therapy, which involved specific serotherapy, infusion therapy, and controlled lung ventilation with the following assisted lung ventilation.