Impact of moisture content on dynamic mechanical properties and transition temperatures of wood

The dynamic shear modulus and the loss modulus of Betula alba, Ulmus parvifolia, Quercus robur, Acer platanoides, Tilia cordata, Fraxinus excelsior and Pinus sylvestris wood were measured using an inverted torsion pendulum within a wide temperature range. The glass transition temperature of the lignin–carbohydrate complex and the decomposition temperature of the wood cellulose were estimated. The temperature band from 170°C to 240°С shows the transition of the lignin–cellulose complex from the glassy to the rubbery state. Mechanical properties of different types of wood are affected by moisture and anatomical differences, but glass transition and decomposition temperatures are the same. More than 5% of moisture in the wood stored at normal conditions were found. After drying, the increase of dynamic shear modulus of wood over the entire region of the glassy state was observed. The intensity of maximum peak of dynamic loss modulus is also increased due to activation of the segmental motion of macromolecules of the ligno-carbon complex. The decomposition temperature of the cellulose crystallites was unchanged for specimens containing moisture and for dried specimens.     

Analysis of oil composition in cultivars and wild species of oat (Avena sp.)

Oil quality and content were analyzed in 33 accessions from 13 wild species and 10 accessions of cultivated oat. Wild oat species tended to have higher oil and 18:1 fatty acid (FA) contents and lower amounts of 18:2 and 18:3 FAs as compared to cultivated oats. In addition to common FAs, minor amounts of several hydroxy and epoxy FAs were also present in the oat oil and mainly confined to specific lipid classes. These unusual FAs included the previously reported 15-hydroxy 18:2 (Delta9,12) (avenoleic acid) mostly found among polar lipids and a novel 7-hydroxyhexadecanoic acid located to 1,2-diacylglycerol. The present study highlights the potential of making use of the existing germplasm, consisting of wild oat species, in breeding programs for achieving new oat varieties that produce a range of oils with different FA compositions as well as having high oil contents. However, in one matter, oats apparently lack genetic diversity and that is for oil qualities that are highly enriched in the omega 3 (omega-3) FA 18:3. Consequently, developing oat cultivars with highly unsaturated oils will need involvement of other techniques such as biotechnology.     

Nikolay I. Makkaveev and the development of Fluvial Geomorphology in Russia and the former Soviet Union

2008 marks the centenary of the birth of Professor Nikolay Ivanovich Makkaveev (1908–1983), a former Professor in the Faculty of Geography at Moscow State University and the founder of the Laboratory of Soil Erosion and Fluvial Processes in the Faculty of Geography.     

Cadmium Affects the Interaction Between Peas and Root Nodule Bacteria

This study investigated the ability of Rhizobium soil inoculants isolated from cadmium (Cd)-contaminated soils to form effective symbioses with peas in the presence of Cd. With Cd present, certain isolates induced high pea dry matter production; an isolate, G, from 399-ppm Cd soil induced high nitrogen uptake and one from 33-ppm Cd, C, soil accelerated Cd uptake. Promising isolates regarding Cd response were used to inoculate various pea selects. Transmission electron microscope analyses showed differences in Cd tolerance between bacterial isolates and pea selects.     

Sensitivity and specificity improvement of an ion sensitive field effect transistors-based biosensor for potato glycoalkaloids detection

Butyryl cholinesterase of different origin along with variations of the time of enzyme immobilization on the potentiometric transducer surface is offered to control the ion sensitive field effect transistor (ISFET)-based biosensor sensitivity. Because butyryl cholinesterase has been already used to develop the sensors for heavy metals, organophosphorus/carbamate pesticides, and steroidal glycoalkaloids analysis, the present study has been focused on the investigation and adjustment of the ISFET-based biosensor specificity exclusively to the glycoalkaloids. Utilization of ethylendiaminetetracetate (a complexon of heavy metal ions) and phosphotriesterase (a highly efficient catalyst for the hydrolysis of organophosphorus compounds) enabled the highly specific determination of glycoalkaloids at the background of lead and mercury (up to 500 microM of ions concentration) and paraoxon (up to 100 microM of pesticide concentration). The developed biosensor has been validated for glycoalkaloids detection in potato varieties cultivated in Ukraine, and the results obtained are compared to those measured by the methods of HPLC and TLC.     

Anthropogenic Ammonia Emissions in the Former USSR in 1990

Ammonia emissions originate from different and widely distributed sources. The bulk of anthropogenic NH₃ emissions are connected with agriculture and a smaller part with industry. The default emission factors recommended by the Economical Commission for Europe are applied to evaluate NH₃ emissions from the former USSR. The following categories of agricultural activities are considered: cattle, pigs, poultry, horses, sheep, goats, fur animals, rabbits, reindeers and fertiliser application. Human and home pet metabolism as a source of NH₃ is also considered. Industrial sources include combustion processes and production of fertilisers, ammonia, coke. Emissions from landfills are also considered. Uncertainties of emission values for each category of sources are estimated. Ammonia emissions are calculated separately for all former republics for the year 1990. The total emissions for Russia are spatially distributed over the territory with 1° × 1° resolution. The data on NH₃ emissions can be used in model calculations of long-range (transboundary) transport of acidifying compounds.     

A Multi-Omics Characterization of the Natural Product Potential of Tropical Filamentous Marine Cyanobacteria

Microbial natural products are important for the understanding of microbial interactions, chemical defense and communication, and have also served as an inspirational source for numerous pharmaceutical drugs. Tropical marine cyanobacteria have been highlighted as a great source of new natural products, however, few reports have appeared wherein a multi-omics approach has been used to study their natural products potential (i.e., reports are often focused on an individual natural product and its biosynthesis). This study focuses on describing the natural product genetic potential as well as the expressed natural product molecules in benthic tropical cyanobacteria. We collected from several sites around the world and sequenced the genomes of 24 tropical filamentous marine cyanobacteria. The informatics program antiSMASH was used to annotate the major classes of gene clusters. BiG-SCAPE phylum-wide analysis revealed the most promising strains for natural product discovery among these cyanobacteria. LCMS/MS-based metabolomics highlighted the most abundant molecules and molecular classes among 10 of these marine cyanobacterial samples. We observed that despite many genes encoding for peptidic natural products, peptides were not as abundant as lipids and lipopeptides in the chemical extracts. Our results highlight a number of highly interesting biosynthetic gene clusters for genome mining among these cyanobacterial samples.     

Influence of climate change,fire and harvest on the carbon dynamics of black spruce in Central Canada

The results of EFIMOD simulations for black spruce (Picea mariana [Miller]) forests in Central Canada show that climate warming, fire, harvesting and insects significantly influence net primary productivity (NPP), soil respiration (Rs), net ecosystem production (NEP) and pools of tree biomass and soil organic matter (SOM). The effects of six climate change scenarios demonstrated similar increasing trends of NPP and stand productivity. The disturbances led to a strong decrease in NPP, stand productivity, soil organic matter (SOM) and nitrogen (N) pools with an increase in CO₂ emission to the atmosphere. However the accumulated NEP for 150 years under harvest and fire fluctuated around zero. It becames negative only at a more frequent disturbance regime with four forest fires during the period of simulation. The results from this study show that changes in climate and disturbance regimes might substantially change the NPP as well as the C and N balance, resulting in major changes in the C pools of the vegetation and soil under black spruce forests.