Heat balance of the Earth

Results of improved calculations of the heat balance components of Earth's surface are reported for yearly average conditions. The technique used to determine the heat-balance components from land- and sea-based actinometric observations as well as from satellite data on the radiation balance of the Earth-atmosphere system is described, with special attention given to short-wavelength solar radiation on the continents, effective radiation from the land surface, the radiation balance of the ocean surface, heat expended by both evaporation from the ocean surface, and turbulent heat transfer between the ocean surface and the atmosphere. World maps of heat-balance components show yearly average values of total radiation, radiation balance, heat expended by evaporation, the turbulent heat flow between Earth's surface and atmosphere, and heat transfer between the ocean surface and underlying waters. The global surface heat balance is estimated along with global values of the various components and the heat-balance components for different latitude zones

Transcriptional Activation of REST by Sp1 in Huntington's Disease Models

In Huntington's disease (HD), mutant huntingtin (mHtt) disrupts the normal transcriptional program of disease neurons by altering the function of several gene expression regulators such as Sp1. REST (Repressor Element-1 Silencing Transcription Factor), a key regulator of neuronal differentiation, is also aberrantly activated in HD by a mechanism that remains unclear. Here, we show that the level of REST mRNA is increased in HD mice and in NG108 cells differentiated into neuronal-like cells and expressing a toxic mHtt fragment. Using luciferase reporter gene assay, we delimited the REST promoter regions essential for mHtt-mediated REST upregulation and found that they contain Sp factor binding sites. We provide evidence that Sp1 and Sp3 bind REST promoter and interplay to fine-tune REST transcription. In undifferentiated NG108 cells, Sp1 and Sp3 have antagonistic effect, Sp1 acting as an activator and Sp3 as a repressor. Upon neuronal differentiation, we show that the amount and ratio of Sp1/Sp3 proteins decline, as does REST expression, and that the transcriptional role of Sp3 shifts toward a weak activator. Therefore, our results provide new molecular information to the transcriptional regulation of REST during neuronal differentiation. Importantly, specific knockdown of Sp1 abolishes REST upregulation in NG108 neuronal-like cells expressing mHtt. Our data together with earlier reports suggest that mHtt triggers a pathogenic cascade involving Sp1 activation, which leads to REST upregulation and repression of neuronal genes

Structural Heterogeneity and Quantitative FRET Efficiency Distributions of Polyprolines through a Hybrid Atomistic Simulation and Monte Carlo Approach

Förster Resonance Energy Transfer (FRET) experiments probe molecular distances via distance dependent energy transfer from an excited donor dye to an acceptor dye. Single molecule experiments not only probe average distances, but also distance distributions or even fluctuations, and thus provide a powerful tool to study biomolecular structure and dynamics. However, the measured energy transfer efficiency depends not only on the distance between the dyes, but also on their mutual orientation, which is typically inaccessible to experiments. Thus, assumptions on the orientation distributions and averages are usually made, limiting the accuracy of the distance distributions extracted from FRET experiments. Here, we demonstrate that by combining single molecule FRET experiments with the mutual dye orientation statistics obtained from Molecular Dynamics (MD) simulations, improved estimates of distances and distributions are obtained. From the simulated time-dependent mutual orientations, FRET efficiencies are calculated and the full statistics of individual photon absorption, energy transfer, and photon emission events is obtained from subsequent Monte Carlo (MC) simulations of the FRET kinetics. All recorded emission events are collected to bursts from which efficiency distributions are calculated in close resemblance to the actual FRET experiment, taking shot noise fully into account. Using polyproline chains with attached Alexa 488 and Alexa 594 dyes as a test system, we demonstrate the feasibility of this approach by direct comparison to experimental data. We identified cis-isomers and different static local environments as sources of the experimentally observed heterogeneity. Reconstructions of distance distributions from experimental data at different levels of theory demonstrate how the respective underlying assumptions and approximations affect the obtained accuracy. Our results show that dye fluctuations obtained from MD simulations, combined with MC single photon kinetics, provide a versatile tool to improve the accuracy of distance distributions that can be extracted from measured single molecule FRET efficiencies

Melanosomes in pigmented epithelia maintain eye lens transparency during zebrafish embryonic development

Altered levels of trace elements are associated with increased oxidative stress that is eventually responsible for pathologic conditions. Oxidative stress has been proposed to be involved in eye diseases, including cataract formation. We visualized the distribution of metals and other trace elements in the eye of zebrafish embryos by micro X-ray fluorescence (mu-XRF) imaging. Many elements showed highest accumulation in the retinal pigment epithelium (RPE) of the zebrafish embryo. Knockdown of the zebrafish brown locus homologues tyrp1a/b eliminated accumulation of these elements in the RPE, indicating that they are bound by mature melanosomes. Furthermore, albino (slc45a2) mutants, which completely lack melanosomes, developed abnormal lens reflections similar to the congenital cataract caused by mutation of the myosin chaperon Unc45b, and an in situ spin trapping assay revealed increased oxidative stress in the lens of albino mutants. Finally transplanting a wildtype lens into an albino mutant background resulted in cataract formation. These data suggest that melanosomes in pigment epithelial cells protect the lens from oxidative stress during embryonic development, likely by buffering trace elements.Peer reviewe

СТАТИСТИЧНИЙ АНАЛІЗ ЧИСЛА РОЗДІЛЕННЯ ВІДЧЕПІВ НА СТРІЛКАХ ПРИ РОЗФОРМУВАННІ СКЛАДІВ

 The procedure of determination of disintegration matrix of the uncoupled parts of a train has been developed. The statistical analysis of a number of disintegrations and its connection with a number of the uncoupled train parts has been also performed.Разработана методика определения матрицы разделений отцепов состава, выполнен статистический анализ числа разделений и его связи с числом отцепов в составе.Розроблена методика визначення матриці розділень відчепів составу, виконано статистичний аналіз числа розділень та його зв’язку з числом відчепів у составі

STATISTICAL ANALYSIS OF THE CUTS DIVISIONS NUMBER ON THE ARROWS AT THE DISSOLUTION OF THE ROLLING STOCKS

The procedure of determination of disintegration matrix of the uncoupled parts of a train has been developed. The statistical analysis of a number of disintegrations and its connection with a number of the uncoupled train parts has been also performed

The peculiarities of hormonal background in boars under correction of reproductive capacity by gadolinium orthovanadate nanoparticles

Determination of the influence of redox nanomaterials on the body of males is of great interest to researchers, because the basis of the pathogenesis of male infertility is oxidative stress. A necessary condition in the development of such drugs is the absence of toxic effects on sexual function. It has been proved that nanomaterials based on oxides of rare earth elements have a positive effect on reproductive capacity and, at the same time, they are not gonadotoxic. A comprehensive approach is of particular importance in order to justify their use as a means of reproductive capacity correction. Taking into account the toxicity parameters the mechanisms of their action need to be studied at the biochemical, morphological and clinical levels. The positive effect of gadolinium orthovanadate nanoparticles on the quality of boar sperm (especially in terms of motility and the number of motile sperm in the ejaculate) with an effective reduction of the oxidative load on the body have been shown. The aim of this study was to determine the effect of these nanoparticles on the hormonal background of males with a decreased reproductive capacity under oxidative stress. Thus, the administration of hydrosol of gadolinium orthovanadate nanoparticles for 14 days revealed a normalization of sex hormones – an increase in total testosterone, in particular, on the 15th day of the study – by 22.6 % (P ˂ 0.01), and on the 30th day – by 77.4 % (P ˂ 0.001) compared with the group of animals before the administration. There was a decrease in the level of 17β-estradiol on the 30th day – by 25.0 % (P ˂ 0.01), which almost reached the values of the control group. A decrease in the content of globulin testosterone-estradiol-binding in boars of the experimental group, in particular, on the 15th day of the experiment – by 13.0 % (P ˂ 0.05), and on the 30th day – by 26.8 % (P ˂ 0.001) was determined, which, in turn, led to an increase in androgen saturation of the animal body – the index of free androgens at the end of the study was 43.2 %. The results are explained by the properties of the nanoparticles. Correcting oxidative stress, they increase the antioxidant potential, thereby normalizing the activity of endocrine glands and ways of regulating the germ-endocrine function of the gonads. The prospect of further research is to elucidate the effect of the correction of decreased reproductive capacity in boars under oxidative stress by nanoparticles of oxides of rare earth elements on the morphological state of the gonads

DURATION OF POSTVACCINAL IMMUNITY AGAINST HEPATITIS B IN HEALTH CARE WORKERS IN ST. PETERSBURG

Immunization against hepatitis В is the most effective method of preventing this disease. Study of quantitative characteristics of postvaccinal immunity against viral hepatitis В in 214 health care workers from different institutions of St. Petersburg has shown that HBV vaccine provides a long term immunity in 80% of cases with the absence of manifest forms of the disease. The duration of circulation of high titers of antibodies depended on the age of people when vaccination was provided. The highest level of immunity was observed in people vaccinated before the age of 30 years (84,0–90,6%). Reduction of immunity level in vaccinated health care workers after 5 years from the date of vaccination requires revaccination against viral hepatitis B after pre-vaccination screening

Evidence of Exciton Self-Trapping in Pseudoisocyanine J‑Aggregates Formed in Layered Polymer Films

At low temperatures in the luminescence spectrum of pseudoisocyanine (PIC) J-aggregates formed in a layered polymer film an unusual broad red-shifted band appears. The analysis of spectral properties of PIC J-aggregates allowed us to ascribe the additional red band to the exciton self-trapped state. In a layered polymer film, PIC J-aggregates are found to possess a 2D island-like structure, which results in a barrier type of the exciton self-trapping with coexisting free and self-trapped excitons. Both the strong topological disorder and exciton–phonon coupling are suggested to be the reason for the exciton self-trapping in J-aggregates. Nonradiative relaxation of self-trapped excitons at room temperature has been proposed to be responsible for a very low luminescence quantum yield and giant nonradiative rate constant for PIC J-aggregates formed in a layered film

Plasmon Controlled Exciton Fluorescence of Molecular Aggregates

In the present work controlled plasmon enhanced fluorescence of thiacyanine dye J-aggregates in water solution has been demonstrated. To control a distance between J-aggregates and silver nanoparticles the latter have been covered by a polymer shell of variable thickness using the layer-by-layer assembly method. The best 2-fold fluorescence enhancement has been observed for the 16 nm thick polymer shell. Transmission electron microscopy (TEM) images have revealed an insufficient contact between J-aggregates and NPs that could be the main reason for the small fluorescence enhancement. Experimental results have been described using a model of two-level system affected by the local plasmon resonances field. According to the model more than 20-fold enhancement of J-aggregates fluorescence could be expected under optimal conditions. Besides, strong fluorescence enhancement dependence on an exciton coherence length has been predicted. According to it, significant fluorescence response should be observed for metal nanoparticles interacting J-aggregates with large exciton coherence length such as pseudoisocyanine J-aggregates and some others