Application of potassium chloride to a Chernobyl-contaminated lake: modelling the dynamics of radiocaesium in an aquatic ecosystem and decontamination of fish

This study tests a whole-lake experiment to reduce the bioaccumulation of radiocaesium (137Cs) in fish in lakes contaminated by the Chernobyl accident. In many lakes in the Chernobyl contaminated areas, radiocaesium activity concentrations in fish are still significantly higher (up to 100 times in some species) than acceptable limits for human consumption. Estimates of the long-term rate of decline of 137Cs in fish in these regions, in the absence of countermeasures, show that radioactivity in fish in some lakes may remain above acceptable consumption limits for a further 50-100 years from the present date. In February 1998 we applied 15 t of potassium chloride to Lake Svyatoe, Kostiukovichy. The addition of potassium chloride fertilizer to the lake resulted in a decrease in activity concentration of 137Cs to approximately 40% of pre-countermeasure values in a number of different fish species. In contrast to Lake Svyatoe, 137Cs activity concentrations in fish from four control lakes showed no systematic decrease over the study period. Simplified models for transfers of 137Cs in lakes successfully 'blind' predicted the changes in 137Cs in water and fish resulting from this major alteration of the potassium concentration of the lake. The experiment represents the first test of a predictive model for the dynamics of radiocaesium in response to a major perturbation in potassium (its major competitor ion) in a whole lake ecosystem.     

Theory and practice of protection of personal names in the domain space or “renewed” cybersquatting (in terms of the states of Eastern Europe)

With the development of the Internet, more people are creating personal websites and blogs, and they expect to be able to use their own name or surname in the domain name. The aim of this article is to identify and analyse the existing problems in the use and protection of personal names in the domain space, as well as the development of legal approaches that can be used to resolve disputes that arise. In the course of the analysis, the authors conclude that the existing legal regulations at both the international and national levels are not sufficient to protect personal names effectively. Current approaches in this area are scattered and not systematic. The conclusions and suggestions made in this paper can be used to form a specialised procedure to resolve domain name disputes relating to personal names, as well as in the course of organising and updating the national legislations of the states of Eastern Europe.     

Estimating daily gross primary production of maize based only on MODIS WDRVI and shortwave radiation data

Accurate assessment of temporal changes in gross primary production (GPP) is important for carbon budget assessments and evaluating the impact of climate change on crop productivity. The objective of this study was to devise a simple remote sensing-based GPP model to quantify daily GPP of maize. In the model, (1) daily shortwave radiation (SW), derived from the reanalysis data (North American Land Data Assimilation System; NLDAS-2) and (2) smoothed Wide Dynamic Range Vegetation Index (WDRVI) data, derived from Moderate Resolution Imaging Spectroradiometer (MODIS) 250-m observations were used as proxy variables of the incident photosynthetically active radiation (PAR) and the total canopy chlorophyll content, respectively. The model was calibrated and validated by using tower-based CO₂ flux observations over an 8-year period (2001 to 2008) for one rainfed and two irrigated sites planted to maize as part of the Carbon Sequestration Program at the University of Nebraska-Lincoln. The results showed the temporal features of the product SW*WDRVI closely related to the temporal GPP variations in terms of both daily variations and seasonal patterns. The simple GPP model was able to predict the daily GPP values and accumulated GPP values of maize with high accuracy.     

Qualitative detection of Mg content in a leaf of Hedera helix by using X-ray radiation from a laser plasma source

In this article, a method to reveal the presence of Mg content inside the different parts of leaves of Hedera helix is presented. In fact a sample of a Hedera helix's leaf, commonly characterized by a green and a white side, is analyzed under X-ray radiation. The presence of two zones with different colors in the Hedera helix's leaf has not been explained. In this connection, there are presently three hypotheses to explain the characteristic double-color appearance of the leaf. The first hypothesis suggests a different cytoplasmic inheritance of chloroplasts at the cell division, the second a different allelic composition, homozygote and heterozygote, between the two zones, and finally the third the action of a virus which changes the color properties in the Hedera's leaves. The resulting effect is a different content of "something" between the green and the white side. We utilized X-ray radiation, obtained from a plasma source with a Mg target, to image Hedera helix leaves and we found that the green side of the leaf is highlighted. We may suppose that the reason why the X-rays from a Mg plasma source, allow us to pick up the green side is probably due to the greater presence of the amount of Mg (from chlorophyll or other complexes and/or salts) in the two sides, green and white, of the leaf.     

All-Solid-State Electro-Chemo-Mechanical Actuator Operating at Room Temperature

Dimensional change in a solid due to electrochemically driven compositional change is termed electro-chemo-mechanical (ECM) coupling. This effect causes mechanical instability in Li-ion batteries and solid oxide fuel cells. Nevertheless, it can generate considerable force and deformation, making it attractive for mechanical actuation. Here a Si-compatible ECM actuator in the form of a 2 mm diameter membrane is demonstrated. Actuation results from oxygen ion transfer between two 0.1  µ m thick Ti oxide\Ce_0.8Gd_0.2O_1.9 nanocomposite layers separated by a 1.5  µ m thick Ce_0.8Gd_0.2O_1.9 solid electrolyte. The chemical reaction responsible for stress generation is electrochemical oxidation/reduction in the composites. Under ambient conditions, application of 5 V DC produces actuator response within seconds, generating vertical displacement of several µm with calculated stress ≈ 3.5 MPa. The membrane actuator preserves its final mechanical state for more than 1 h following voltage removal. These characteristics uniquely suit ECM actuators for room temperature applications in Si-integrated microelectromechanical systems.     

Intercomparison of satellite and ground-based measurements of ozone,NO2, HF,and HCl near Saint Petersburg,Russia

Regular intercomparison of different observing systems is a part of their testing and validation protocol, which gives the estimates of real measurement errors. The main objective of our study is the comparison of satellite and ground-based measurements of atmospheric composition near Saint Petersburg, Russia. Since early 2009, high-resolution Fourier Transform Infrared (FTIR) solar absorption spectra have been recorded at Peterhof station (59.82° N, 29.88° E), located in the suburbs of Saint Petersburg. We derived column amounts of O₃, HCl, HF, and NO₂ from these spectra using the retrieval codes SFIT2 and PROFFIT. We compared the data retrieved from Bruker 125 HR FTIR measurements with coincident satellite observations of the Microwave Limb Sounding (MLS), Ozone Monitoring Instrument (OMI), Fourier Transform Spectrometer from Atmospheric Chemistry Experiment (ACE-FTS), Global Ozone Monitoring Experiment (GOME and GOME-2), and Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) instruments. The relative differences in ozone columns of FTIR from OMI-TOMS amount within (+3.4 ± 2.9)%, from GOME-2 are (+2.2 ± 3.0)%. The comparison of FTIR and MLS measurements of stratospheric ozone columns gives no mean and 5% of the RMS differences. Measurements of NO₂ columns agree with the mean difference of +9% and the RMS differences within 14–16% for FTIR vs. GOME-2, SCIAMACHY, and OMI. FTIR vs. GOME comparison gives (+6 ± 31)%. HCl columns comparison for FTIR vs. MLS shows ?4.5% in the mean and 12% in the RMS differences. FTIR vs. ACE-FTS comparison (nine cases) gives ?8% and 10% for the mean and the RMS relative differences, respectively. Comparison of HF columns shows (?12 ± 6)% and (?12 ± 11)% for FTIR vs. ACE data v.2.2 and v.3.0, respectively. These figures show that the Peterhof ground-based FTIR measuring system can be used to support the validation of satellite data in the monitoring of stratospheric gases.     

First measurements of formaldehyde integral content in the atmosphere using MAX-DOAS in the Moscow region

We present the first observations of formaldehyde (HCHO) atmospheric column performed for Zvenigorod, Moscow region, Russia. The data were retrieved from UV spectra of the scattered solar radiation measured by the multi-axis differential optical absorption spectroscopy (MAX-DOAS) instrument developed by the Japan Agency for Marine-Earth Science and Technology. We developed an algorithm for the HCHO retrieval from these spectra. For retrieval of the HCHO differential slant column densities, we used the DOAS settings used as baseline in the Cabauw Intercomparison Campaign of Nitrogen Dioxide Measuring Instruments (CINDI). The slant column densities of HCHO were converted to vertical column densities (VCDs) using the air mass factors calculated by a radiative transfer model. The determination of HCHO in the reference spectrum used multi-axis measurements.

The variability of the HCHO vertical column in 2010 is analysed. The HCHO vertical column density is larger during east wind directions than during non-east wind directions. This can be associated with the Moscow Megacity influence on air quality at Zvenigorod. The estimation of the Moscow Megacity influence on HCHO abundance at Zvenigorod is around 2.5 × 10¹⁴ molec cm^?2 per 1 km length of trajectory path inside the Moscow Ring Road.

A temperature effect is noticeable in the HCHO VCD. Our data show a statistically significant positive temperature effect in HCHO for the background condition for temperatures from ?5°C to +33°C. The temperature trend in HCHO data at Zvenigorod Scientific Station is about (8.9 ± 2.3) × 10¹⁴ molec cm^?2 (°C)^?1. The increase of the HCHO VCD during increase of the air temperature can be explained by the HCHO formation from non-methane biogenic volatile organic compounds (e.g. isoprene) for which more emission is expected at higher temperatures, and by growth of areas of forest and turf fires.     

Triple point mutation Asp10 -> His, Asn101 -> Asp, Argl48 -> Ser in T4 phage lysozyme leads to the molten globule

The triple amino acid replacement (Asp10 His, Asn101 Asp,Arg148 Ser) in T4 phage lysozyme was carried out by site-directedmutagenesis. At acid pH (2.7) the mutant is in a confonnationalstate with the properties of the molten globule: (i) the mutantprotein molecule is essentially compact; (ii) its CD spectrumin the near UV region is drastically reduced in intensity ascompared with the wild type protein spectrum; (iii) the CD spectrumin the far UV region indicates the presence of pronounced secondarystructure in the mutant; (iv) unlike the wild type protein themutant protein can bind the hydrophobic fluorescent probe, ANS.