The variation of tree-ring widths of Scots pine (Pinus sylvestris L.) affected by air pollution

Using eight populations of Scots pine growing in foothills of the Sudetes (southern Poland) as an example, the character and causes of annual ring variation in 1900–1999 were studied. The climate had a short-term effect on radial growth during the whole period investigated. A long-term decrease of radial growth occurred after 1960, but only in some localities. It was probably caused by non-climatic factors, most likely by industrial pollution. The decline of trees during that period is mainly evidenced by a high variation of width of annual rings, a small similarity of chronologies of annual ring widths, and a lack of signal years. After 1990, the tree recovery process was evident. It was most intensive in localities where the earlier stress was the most severe. Then, trees started to produce wide annual rings, homogeneity of the growth reaction increased, and the signal years began to occur.     

High-speed steel tool wear during wood cutting in the presence of high-temperature corrosion and mineral contamination

Dulling of high-speed steel (HSS) cutting tools after milling five wood species has been analyzed. The wood investigated varied in mineral contamination, high-temperature corrosivity (HTC) and density (D). Experiments performed proved that up to date methods for evaluation of mineral contamination in wood should be improved. A new pipe-like form of mineral contamination particles was evidenced. The correlation between the presence of 3D aggregates of silica in wood and high content of K and Ca in the ash was established. Employing multivariable theoretical simulation method, the combined effect of mineral contamination, HTC and wood density on the tool dullness appeared to be a reasonable explanation of the results obtained.     

Co‐expression of PACAP with VIP,SP and CGRP in the Porcine Nodose Ganglion Sensory Neurons

Our previous study revealed the expression of substance P (SP) and calcitonin gene‐related peptide (CGRP) in sensory distal ganglion of the vagus (nodose ganglion) neurons in the pig. As these neuropeptides may be involved in nociception, the goal of these investigations was to determine possible expression of vasoactive intestinal polypeptide (VIP), SP and CGRP in the pituitary adenylate cyclase‐activating polypeptide‐immunoreactive (PACAP‐IR) porcine nodose perikarya. Co‐expression of these substances was examined using a double‐labelling immunofluorescence technique. To reveal the ganglionic cell bodies, the pan‐neuronal marker protein gene product 9.5 (PGP 9.5) was used. Quantitative analysis of the neurons revealed that 67.25% of the PGP 9.5+ somata in the right‐side ganglion and 66.5% in the left side, respectively, co‐expressed PACAP‐IR. Moreover, 60.6% of the PACAP‐IR cells in the right‐side ganglion and 62.1% in the left, respectively, co‐expressed VIP. SP‐IR was observed in 52.2 and 39.9% of the right and left ganglia, respectively. CGRP was found in 27.7 and 34.1% of the right and left distal ganglion of the vagus, respectively. High level of co‐expression of PACAP with VIP, SP and CGRP in the distal ganglia of the vagus sensory perikarya directly implicates studied peptides in their functional interaction during nociceptive vagal transduction.     

Synthesis and phytotoxicity of new ionic liquids incorporating chiral cations and/or chiral anions

The aim of this work was to synthesize chiral ionic liquids as chiral solvents for organic synthesis and to evaluate the phyto(eco)toxicity of the new products and starting N-alkylimidazoles and their potential environmental influence on soil and plants. Chiral ionic liquids containing anions such as Cl-, Br-, TsO-, PF6(-), NO3(-), CF3SO3(-), and (+)- and (-)-C6H5CH(OH)C(O)O- were synthesized using (-)-(1R)-6,6-dimethylbicyclo[3.1.1]hept-2-ene-2-ethyl [(-)-(1R)-nopyl] halides (X = Cl, Br) and tosylate in 62-100% yields. The chloride 7 and the nitrate 13 ionic liquids possessed a toxicity dependent on the applied concentration. The lowest concentration causing a distinct reduction in plant germination/growth was 100 mg/kg. Spring barley better tolerated the ionic liquids (200 mg/kg) than common radish (100 mg/kg). The nitrate liquid did not exhibit an inhibiting effect on the germination ability of seeds. The starting N-methylimidazole used in lower concentrations (1 and 10 mg/kg of soil dry weight) was not phytotoxic, in contrast to higher doses (>1000 mg/kg).     

Plant P5C reductase as a new target for aminomethylenebisphosphonates

A series of N-substituted derivatives of aminomethylenebisphosphonic acid were evaluated as potential inhibitors of delta1-pyrroline-5-carboxylate reductase (EC 1.5.1.2), the enzyme that catalyzes the last step in proline biosynthesis, partially purified from Arabidopsis thaliana suspension cultured cells. At millimolar concentrations, three compounds out of 26 were found to interfere with the catalytic mechanism. One of them, namely, 3,5-dichloropyridyl-aminomethylenebisphosphonic acid, retained such inhibitory activity in the micromolar range. Kinetic analyses ruled out the possibility that the inhibition could simply rely upon the chelating properties of bisphosphonates and showed mechanisms of a noncompetitive type against NADH and an uncompetitive type against delta1-pyrroline-5-carboxylic acid, with KI values of 199 +/- 6 and 10.3 +/- 1.5 microM, respectively. A computer-aided docking analysis, performed on the basis of the crystal structure of the enzyme from Streptococcus pyogenes, suggested that this phosphonate may interact with amino acid residues near the binding site of delta1-pyrroline-5-carboxylic acid, thus blocking the substrate in a pocket and preventing its interaction with NADH. Because in higher plants the step catalyzed by delta1-pyrroline-5-carboxylate reductase is shared by all pathways leading to proline synthesis, such a compound may represent a lead structure to be exploited for the design of new substances endowed with herbicidal activity.     

Survival,growth and photochemical efficiency of silver fir seedlings produced with different technologies

New Forests - Forest tree seedling production technologies impact reforestation success determined with survival and quality of seedlings. Five Abies alba seedling production technologies were...     

Rates of oxygen consumption and ammonia excretion of juvenile Eurasian perch Perca fluviatilis L.

The impact of feeding, fish size (body weight from 18.5 to 56.5 g) and water temperature (20 and 23 °C) on oxygen consumption (OC, mg O₂ kg^–1 h^–1) and ammonia excretion (AE, mg TAN kg^–1 h^–1) was studied in Eurasian perch held in recirculation systems. OC for both fed and feed-deprived (3 days) fish was higher at 23 °C (278.5 and 150.1 mg O₂ kg^–1 h^–1) than at 20 °C (249.3 and 135.0 mg O₂ kg^–1 h^–1; P < 0.01). AEs for both fed and feed-deprived fish were also significantly higher at 23 °C than at 20 °C (P < 0.001). Water temperature and fish size had a significant impact on the oxygen:feed ratio (OFR, kg O₂ kg^–1 feed fed day^–1) and ammonia:feed ratio (AFR, kg TAN kg^–1 feed fed day^–1; P < 0.001). Their average values at temperatures of 20 and 23 °C were 0.17 and 0.19 kg O₂ kg^–1 feed fed day^–1 and 0.009 and 0.011 kg TAN kg^–1 feed fed day^–1, respectively.