Search results for "ABUNDANCE"

2015

Chemical ligation has been used to alter motions in specific regions of dihydrofolate reductase from E. coli and to investigate the effects of localized motional changes on enzyme catalysis. Two isotopic hybrids were prepared; one with the mobile N-terminal segment containing heavy isotopes (2H, 13C, 15N) and the remainder of the protein with natural isotopic abundance, and the other one with only the C-terminal segment isotopically labeled. Kinetic investigations indicated that isotopic substitution of the N-terminal segment affected only a physical step of catalysis, whereas the enzyme chemistry was affected by protein motions from the C-terminal segment. QM/MM studies support the idea th…

The effect of Shallow Tillage on soil erosion in a semi-arid vineyard

2019

Soil erosion has been considered a threat for semi-arid lands due to the removal of solid materials by water and wind. Although water erosion is currently considered the most important process of soil degradation, a growing interest has been drawn to the impact of soil tillage. Although numerous studies on tillage erosion have been carried out on arable land using a moldboard plow, a chisel, and a tandem disc for different crops, there are no studies on the effect of shallow tillage on soil redistribution in vineyards. The aim of this work was to evaluate the soil tillage erosion rate in a vineyard using a 13C natural abundance tracer. A strip of soil (C3-C soil) was removed, mixed with C4-…

Investigating the impact of anthropogenic land use on a hemiboreal lake ecosystem using carbon/nitrogen ratios and coupled-optical emission spectrosc…

2019

Anthropogenic impacts on lake ecosystems have increased substantially towards the present. However, the strength and timing in most cases are not evaluated in detail, missing valuable information on the response and recovery of an aquatic system. In this study, we use the sediment total organic carbon/total nitrogen ratio (C/N) and inductively coupled-optical emission spectroscopy (ICP-OES) elements and the available information about the biological processes to explore anthropogenic land use impact on the lake ecosystem. As a case study we selected a hemiboreal lake Trikātas (Latvia, NE Europe). The Pearson correlation was used to statistically test the correlations of all variables. Our r…

Complexation of C-methyl pyrogallarene with small quaternary and tertiary alkyl ammonium cations

2007

Complexation properties of pyrogallarene 1 towards small quaternary and tertiary alkyl ammonium cations were studied in gas phase, solution and in solid state. In gas phase both dimeric capsules and monomeric 1 : 1 complexes of all cations 2a+–d+ are detected but only in the case of 2a+ is the abundance of the capsule form higher than the monomeric 1 : 1 complex. A similar trend is observed in NMR experiments, which reveal a favourable dimeric complex for 2a+ and a weaker dimeric complex for 2b+ but only monomeric complexes for 2c+ and 2d+. Also in solid state, 2a+ and 2b+ form capsules when crystallized from MeOH while 2c+ and 2d+ form dimeric 1 : 1 complexes. As a reference, hetero-confor…

Detection of RNA modifications

2010

RNA nucleotide modifications are typically of low abundance and frequently go unnoticed by standard detection methods of molecular biology and cell biology. With a burst of knowledge intruding from such diverse areas as genomics, structural biology, regulation of gene expression and immunology, it becomes increasingly clear that many exciting functions of nucleotide modifications remain to be explored. It follows in turn that the biology of nucleotide modification and editing is a field poised to rapidly gain importance in a variety of fields. The detection and analysis of nucleotide modifications present a clear limitation in this respect. Here, various methods for detection of nucleotide …

The fouling community as an indicator of fish farming impact in Mediterranean

2007

Fouling species richness, abundance and composition and biomass were chosen as the descriptors of effect of fish farm organic enrichment. The study was carried out in September 2004 in the Gulf of Castellammare (South Tyrrhenian, Mediterranean). The fouling species were sampled from plastic buoys spaced throughout the study area both up- [UP] and down-stream [DOWN]. The results showed that fouling community responded to the chronic input of allochthonous organic matter experiencing local changes more or less significantly with regard to abundance, species composition and general community diversity. Upper fouling would work as a first filter naturally opposed by environment resistance assim…

Temporal fatty acid profiles of human decomposition fluid in soil

2017

Abstract We studied the changes in concentration and relative abundance of human-derived fatty acids (FAs) in soil over a period of one year. The study is based on analysis of soil underneath a human body that lay on the soil surface for 18 days before it was discovered. Soil samples were taken when the body was removed, and also 358 days later. Large amounts of the total FA concentration at the start of the measurement period were still present one year after the removal of the body. The FA profile suggested that extensive saturated FA reduction occurred during the first 18 days after deposition. 10-Hydroxystearic acid and FA salts, which are characteristic of adipocere, were abundant in a…

Abundance and activity of nitrate reducers in an arable soil are more affected by temporal variation and soil depth than by elevated atmospheric [CO2]

2011

Elevated atmospheric carbon dioxide concentrations ([CO2]) might change the abundance and the function of soil microorganisms in the depth profile of agricultural soils by plant-mediated reactions. The seasonal pattern of abundance and activity of nitrate-reducing bacteria was studied in a Mini-FACE experiment planted with oilseed rape (Brassica napus). Three depths (0–10, 10–20 and 20–30 cm) were sampled. Analyses of the abundances of total (16S rRNA gene) and nitrate-reducing bacteria (narG, napA) revealed strong influences of sampling date and depth, but no [CO2] effects. Abundance and activity of nitrate reducers were higher in the top soil layer and decreased with depth but were not re…

A STUDY ON THE POSSIBLE EFFECT OF TWO CRAYFISH SPECIES ON EPILITHIC ALGAE IN A MOUNTAIN STREAM FROM CENTRAL SPAIN

2006

The effects on epilithic algae of increasing densities of two crayfish species, Austropotamobius italicus and Pacifastacus leniusculus, the latter recently introduced in Spain, have been monitored using riverine enclosures, within a large experimental study on crayfish-macrobenthos interactions in a mountain stream. A 3-month test was carried out for each species using crayfish densities comprising between 0-5 individuals/m2 kept in 1-m2 enclosures. Epilithon was sampled periodically within the enclosures and chlorophyll a, b and c were measured by spectrophotometry. Neither statistically significant positive nor negative effects were observed on algal abundance (Chl concentrations) during …

ON THE ONSET OF POST-COMMUNIST INDUSTRIAL DEVELOPMENT IN CENTRAL AND EAST EUROPEAN ECONOMIES

2013

In the course of the last twenty odd years, Central and East-European economies have been striving to reform an inherited flawed trade structure, in an attempt to increase their industrial competitiveness and improve their position within the international division of labor. The respective countries have gone through an industrial metamorphosis that swept away the legacy of socialist autarky, making them better-equipped to deal with globalization challenges. The dismantling of the COMECON forced CEEs to institute severe constraints on public budgets; as a consequence, the price of physical capital edged up relative to the price of labor thereby making the respective economies relative abund…