Crossbreeding of cattle: effects on milk production

International audienc

Biological and chemical diversity of Angelica archangelica L. — case study of essential oil and its biological activity

Garden angelica (Angelica archangelica L.), native to the northern temperate region, is widespread in Europe and Asia. Since the middle ages, it has been used for healing and as a vegetable in traditional dishes. In the modern era, it has been proven that A. archangelica has a complex chemical composition. The main derivatives that contribute to the plant’s biological activities are essential oil and coumarins. In this review, the focus is on the cross-analysis of the taxonomy of A. archangelica, and its distribution in different regions, with the presentation of the richness of its biochemical composition, which overall contributes to the widespread use of the roots of this plant in folk medicine. It belongs to the plants that were introduced to the wider area of Central, Eastern, and Southern Europe; as a medicinal plant, it represents a significant part of the medical flora of many areas. Cluster analysis of pooled data indicates a clear differentiation of chemotypes

Analysis of thick plates by a finite space element

U radu su prikazane mogućnosti prostornog konačnog elementa velike točnosti u linearnoj analizi ploča proizvoljne ali konstantne debljine. Primijenjen je pravokutni trikubični Lagrangeov element s 192 kinematička stupnja slobode. Opisano je analitičko rješenje bisinusoidalnog savijanja zglobno oslonjene ploče i pripadni numerički model. Rezultati usporedbe analitičkog i numeričkog rješenja pokazuju visoki stupanj točnosti pomaka i naprezanja dobivenih numeričkim proračunom.Possibilities of using a highly accurate finite space element in the linear analysis of plates of arbitrary but constant thickness are presented in the paper. The rectangular three cubical Lagrange element with 192 kinematic degrees of freedom is applied in the analysis. The analytical solution for bisinusoidal bending of a hinged plate, as well as an appropriate numerical model, are described. The comparison of analytical and numerical solutions shows a high level of accuracy as to displacement and stress values obtained by numerical analysis

Distribution of macrolide-resistant genes among isolates of macrolideresistant Streptococcus pyogenes and Streptococcus pneumoniae in Serbia

Macrolide resistance in Streptococcus pneumoniae and in group A streptococci (GAS) is a significant problem worldwide. In Serbia, data on the mechanisms of resistance and the corresponding resistance genes in streptococci are largely lacking. Therefore, we analyzed the distribution of macrolide resistance phenotypes and genotypes in 44 macrolideresistant GAS (MRGAS) and 50 macrolide-resistant S. pneumoniae (MRSP) isolates collected in the same period. The double disk diffusion test and PCR were used to analyze resistance phenotypes and resistance genes, respectively. Among MRSP, the MLSB phenotype dominated, whereas the M phenotype was the most prevalent among MRGAS isolates. Consequently, in MRSP, the ermB gene was the most common (n=40, 80%), followed by the mefA gene (n=7,14%). In MRGAS strains, mefA dominated (n=27,61%), followed by ermA (n=15, 33%) and ermB (n=3, 7%). In 3 MRSP isolates no resistance genes were detected, while one MRGAS strain with iMLSB phenotype harbored both ermA and mefA genes

Managing rail service life

The service life of rails depends especially on the operational loads and speeds on the railway lines, as well as on the rail maintenance policy. There are multiple aspects of rail maintenance optimization. The following article considers optimisation of rail maintenance activities relating to rail head surface condition in order to reduce corrective work on track geometry, as well as to minimize the overall costs for track maintenance. The objects of this research are issues and challenges related to rail and track maintenance in curves on modern conventional railway lines for mixed traffic

Toxicological analysis of the risk of lead exposure in metal processing

Purpose: To evaluate toxicological risks for workers who are exposed to lead in their work environment. Methods: Since it is an important indicator of toxicological risk, a statistical analysis of lead concentration and biological lead toxicity markers in blood and urine were performed for both exposed and control groups. Both experimental groups consisted of employees from "NISSAL" JSC factory. Analytical epidemiological method in the form of a retrospective cohort study was applied, and covered the period from 2001 to 2010. The concentration of lead, δ-aminolevulinic acid, and coproporphyrin in biological samples were determined by spectrophotometric methods. Results: The results showed a high positive correlation between lead concentrations in blood and urine and the length of exposure of the participants (p < 0.01). Also, increase of lead concentration in the biological material significantly increased δ-aminolevulinic acid (p < 0.01) and slightly increased the concentration of coproporphyrin, both of which are important indicators of toxicological risk. Conclusion: The control group of employees belonged to the normal risk category, while the exposed group belonged to a moderate risk category. Correlation between the monitored parameters is statistically significant at p < 0.01 and p < 0.05. Keywords: Lead, δ-Aminolevulinic acid, Coproporphyrin, Chronic exposure, Toxicity, Correlatio

Rail inspection of RCF defects

Rail defects due to rolling contact fatigue (RCF) threaten the traffic safety around the world. That hazard is more distinct on railways without adequate maintenance strategy. Realization of interoperability of European railway network demands from every infrastructure manager to have a maintenance plan for the infrastructure subsystem. Besides that, this plan includes rail inspection and strategy against RCF defects. This paper emphasizes the importance of rail inspection and early detection of RCF because the most of RCF crack should be removed in rail grinding campaigns (preventive, cyclical and corrective activities) during the whole rail service life

Evolution of lattice, spin, and charge properties across the phase diagram of FeSe1-x Sx

A Raman scattering study covering the entire substitution range of the FeSe1-xSx solid solution is presented. Data were taken as a function of sulfur concentration x for 0≤x≤1, of temperature and of scattering symmetry. All types of excitations including phonons, spins, and charges are analyzed in detail. It is observed that the energy and width of the iron-related B1g phonon mode vary continuously across the entire range of sulfur substitution. The A1g chalcogenide mode disappears above x=0.23 and reappears at a much higher energy for x=0.69. In a similar way the spectral features appearing at finite doping in A1g symmetry vary discontinuously. The magnetic excitation centered at approximately 500 cm-1 disappears above x=0.23 where the A1g lattice excitations exhibit a discontinuous change in energy. The low-energy mode associated with fluctuations displays maximal intensity at the nematostructural transition and thus tracks the phase boundary

Yttrium Orthoferrite Powder Obtained by the Mechanochemical Synthesis

Yttrium orthoferrite (YFeO3) powder was prepared by a mechanochemical synthesis from a mixture of Y2O3 and alpha-Fe2O3 powders in a planetary ball mill for 2.5 h. The obtained YFeO3 powder sample was characterized by X-ray diffraction (XRD), Raman and infrared spectroscopy. The average crystallite size calculated by the Scherrer equation was 12 nm. The Mossbauer spectroscopy at room temperature confirms the superparamagnetic character of YFeO3 orthoferrite sample

Influence of Radiation Dose in Computed Tomography on Antioxidant Enzyme Activity in Rabbit Erythrocytes

The objective of this study was to assess the radiation dose in computed tomography examinations of rabbits using different examination protocols and to correlate these values with the activity of antioxidant enzymes in their red blood cells following irradiation. The presented results revealed that a single, routine computed tomography scan exposure led to a different response of the activity of antioxidant enzymes in red blood cells regarding both dose and time. The results indicate that there is a dose threshold that is about 25 mGy. Doses below that level do not produce any significant changes in the level of antioxidant enzymes activity. On the other hand, the level just above that threshold had a significant impact on the antioxidant defence, but in a relatively short time period (2 hours after exposure), compared to the higher dose that requires a longer adaptive period