Windthrows in forests of Kostroma oblast and neighboring lands in 1984–2011

A retrospective analysis of windthrows in southern taiga forests (Kostroma oblast and neighboring lands) is performed. The main traits of massive windthrows are calculated. The dominant spatial forms of windthrows are identified. The average annual rates of the forest-cover damage from clearcuts, forest fires, and windblows are compared. The topographical effect on the spatial distribution of fragments of massive windthrows is analyzed.     

Role of 5-aminolevulinic acid in the formation of winter rape resistance to sulfonylurea herbicides

Growing of winter rape (Brassica napus L.) plants for 7–8 days in the presence of a sulfonylurea herbicide Magnum (methsulfuron methyl; 200 and 500 mg/L) exerted an organ-specific influence on the seedlings: suppressed hypocotyl and root growth and increased the accumulation of fresh weight of cotyledonary leaves. Exogenous 5-aminolevulinic acid (ALA; 0.1, 1.0, and 10 mg/L) partially negated the adverse effect of Magnum on the length and fresh weight of roots and hypocotyls and stimulated the development of cotyledons. The herbicide suppressed the activity of ascorbate peroxidase (APX). The addition of ALA to the 200 mg/L herbicide solution caused a steady activation of APX as compared with the effect of herbicide alone. In plants grown on Magnum solutions, the activity of glutathione reductase (GR) rose. Positive effect of exogenous ALA was only observed when 500 mg/L herbicide was used (Magnum-500 type of treatment). In plants grown on the Magnum solution, the content of reduced and oxidized forms of glutathione rose. In contrasty, exogenous ALA reduced the total content of glutathione but in this case the ratio between its reduced and oxidized forms rose. In the presence of the herbicide, the content of anthocyans considerably decreased and upon the addition of exogenous ALA their levels rose. In rape plants treated with Magnum, the ability to generate superoxide anion radical was essentially the same as in control plants; however, the content of hydrogen peroxide (H₂O₂) therein rose. The addition of ALA to the herbicide reduced the ability to generate superoxide anion radical and the level of H₂O₂. The activity of acetolactate synthase remained on the control level when 200 mg/L Magnum was used, decreased in the plants of Magnum-500 treatment, and rose upon the addition of exogenous ALA to this type of treatment. It was concluded that ALA had a positive effect on the development of winter rape resistance to Magnum via stimulation of growth processes, activation of APX and GR, predominant elevation of the content of reduced glutathione and anthocyans, and partial recovery of acetolactate synthase activity, which on the whole caused a decrease in the H₂O₂ level and in the ability of plants to generate superoxide anion radical.     

Structural Insight of a Trimodular Halophilic Cellulase with a Family 46 Carbohydrate-Binding Module

Cellulases are the key enzymes used in the biofuel industry. A typical cellulase contains a catalytic domain connected to a carbohydrate-binding module (CBM) through a flexible linker. Here we report the structure of an atypical trimodular cellulase which harbors a catalytic domain, a CBM46 domain and a rigid CBM_X domain between them. The catalytic domain shows the features of GH5 family, while the CBM46 domain has a sandwich-like structure. The catalytic domain and the CBM46 domain form an extended substrate binding cleft, within which several tryptophan residues are well exposed. Mutagenesis assays indicate that these residues are essential for the enzymatic activities. Gel affinity electrophoresis shows that these tryptophan residues are involved in the polysaccharide substrate binding. Also, electrostatic potential analysis indicates that almost the entire solvent accessible surface of CelB is negatively charged, which is consistent with the halophilic nature of this enzyme.     

Using a Lethality Index to Assess Susceptibility of Tribolium confusum and Oryzaephilus surinamensis to Insecticides

We evaluated knockdown caused by four insecticides: alpha-cypermethrin, chlorfenapyr, pirimiphos-methyl and fipronil against adults of Tribolium confusum Jacquelin Duval, the confused flour beetle and Oryzaephilus surinamensis (L.), the sawtoothed grain beetle. Bioassays were conducted on concrete and metal surfaces. Adults of the tested species were exposed on both surfaces treated with the above insecticides at two doses (low and high). Knockdown assessment was done after 15, 30 and 60 min of adult exposure in the treated surfaces. Also, after 1, 3, 5, 7 and 14 d of exposure, a lethality index was calculated with an equation resulting to values from 0 to 100, where 100 indicated complete mortality and 0 complete survival. We also developed a lethality index by ranking each adult on each surface from 0 to 4, 0: adults moved normally, 1: adults were knocked down, but were able to walk for short intervals, 2: adults were knocked down and unable to walk, but with visible movement of antennae etc., 3: adults were knocked down, with very minimal movement of the tarsi and the antennae and 4: adults were dead (no movement). Knockdown of adults immediately after exposure (15–60 min) was higher for pirimiphos-methyl followed by alpha-cypermethrin, for both dose rates tested and species, but only on the metal surface. The lethality index was nearly 100 for all insecticides after 5d of exposure for O. surinamensis, while for T. confusum the adult lethality index was considerably lower for alpha-cypermethrin, suggesting that that recovery from knockdown occurred. Chlorfenapyr was the only insecticide that was more effective on concrete than on metal, while the reverse was noted for the other three insecticides. These results show that knockdown has different levels, which can be used as indicators of insect mortality or recovery.     

Genome‐wide analysis of Italian sheep diversity reveals a strong geographic pattern and cryptic relationships between breeds

Italy counts several sheep breeds, arisen over centuries as a consequence of ancient and recent genetic and demographic events. To finely reconstruct genetic structure and relationships between Italian sheep, 496 subjects from 19 breeds were typed at 50K single nucleotide polymorphism loci. A subset of foreign breeds from the Sheep HapMap dataset was also included in the analyses. Genetic distances (as visualized either in a network or in a multidimensional scaling analysis of identical by state distances) closely reflected geographic proximity between breeds, with a clear north–south gradient, likely because of high levels of past gene flow and admixture all along the peninsula. Sardinian breeds diverged more from other breeds, a probable consequence of the combined effect of ancient sporadic introgression of feral mouflon and long‐lasting genetic isolation from continental sheep populations. The study allowed the detection of previously undocumented episodes of recent introgression (Delle Langhe into the endangered Altamurana breed) as well as signatures of known, or claimed, historical introgression (Merino into Sopravissana and Gentile di Puglia; Bergamasca into Fabrianese, Appenninica and, to a lesser extent, Leccese). Arguments that would question, from a genomic point of view, the current breed classification of Bergamasca and Biellese into two separate breeds are presented. Finally, a role for traditional transhumance practices in shaping the genetic makeup of Alpine sheep breeds is proposed. The study represents the first exhaustive analysis of Italian sheep diversity in an European context, and it bridges the gap in the previous HapMap panel between Western Mediterranean and Swiss breeds.     

Iron-sulfur centers in the Staphylococcus aureus respiratory chain]

Using low temperature EPR spectroscopy, signals of iron-sulfur centers with g-factors of 2.02 and 1.94 were detected in the respiratory chain of St. aureus membranes. According to their relaxation parameters and redox properties, these iron-sulfur centers are similar to iron-sulfur centers S-1 and S-3 corresponding to succinate dehydrogenases of mitochondria and bacterial membranes.     

Structural similarity and distribution of small cryptic plasmids of Lactobacillus curvatus and L. sake

Plasmid profiles of strains of Lactobacillus curvatus and L. sake isolated from meat or sauerkraut were analysed to investigate plasmid homology and distribution in relation to the ecology of these organisms in fermenting foods. A hybridisation probe was constructed by cloning of pLc2, a cryptic, 2.6-kbp plasmid from L. curvatus LTH683, into the Escherichia coli plasmid pRV50. In Southern hybridisations with the digoxygenine labeled pLc2 probe, pLc2-related small plasmids were frequently detected in meat-borne strains of L. casei subsp. pseudoplantarum, L. curvatus, L. sake, L. alimentarius, L. farciminis and L. halotolerans and in L. curvatus and L. sake isolated from sauerkraut. Among 27 Lactobacillus type strains originally isolated from habitats other than meat this type of homology was detected only with plasmids of L. buchneri and L. mali. Restriction-enzyme mapping of six small cryptic plasmids from L. curvatus and L. sake revealed strong structural homology but no similarity to previously characterized plasmids of lactobacilli. The presence of a variable region in addition to a conserved one and the occurrence of deletions during cloning of pLc2 suggest that vectors derived from these plasmids are likely to be structurally unstable.     

An early Holocene reef in the western Atlantic: submersible investigations of a deep relict reef off the west coast of Barbados,W.I.

Submersible observations and collections reveal that a probable relict reef off the west coast of Barbados has a rich cover of sponges, along with algae and scattered corals, on a substrate of algal nodules in a muddy-sand matrix. The collections provide new data on the distributions of these fauna. This relict reef is about 20 km long, has a relief of up to 10 m, and is established at a depth of 80 m. Relict shallow-water features in other areas at similar depths along with data from core holes drilled off the south coast of Barbados suggest that this reef was probably established about 12,000 years ago and existed for no more than 2,000 years, during the Holocene sea-level transgression.