Genotypic variability of morphological characteristics of English oak (Quercus robur L) acorn

This paper deals with the acorn morphology (length, diameter and mass) analyzed in seventeen English oak genotypes (Quercus robur L)from the English Oak Clonal Seed Orchard Banov Brod (Srem,Vojvodina). The highest values of acorn mass and length were measured in genotype 5. The largest diameters were measured in genotypes 6 and 21. Genotype 35 had the lowest acorn mass, length and diameter. The results from this study should serve as guidelines for the selection of trees yielding fruits possessing the desirable morphological characteristics

Uticaj procesa izluživanja i načina korišćenja rendzina na stepen humificiranosti huminskih kiselina

The humification degrees of humic acids extracted from calcareous and decarbonated Rendzinas under different land use were characterized upon their optical properties, to evaluate the influence of carbonate leaching (decarbonation) and different land uses. Decarbonation influenced the humification degree of humic acids positively. Base leaching and acidification of decarbonated Rendzinas led to a decrease in humification degree of humic acids. In calcareous Rendzinas, the humification degree of humic acids was in descending order: grassland>arable land>forest land, and in decarbonated Rendzinas: arable land>grassland>forest land. The humification degree of humic acids was higher in the calcareous forest and grassland Rendzinas compared to decarbonated Rendzinas, analogously in decarbonated arable land compared to calcareous arable land Rendzinas. Differences in the humification degree of humic acids among various land uses that emerged between calcareous and decarbonated Rendzinas indicate the dominant influence of soil chemical characteristics (carbonate content and pH value) compared with the quantity and quality of the organic litter input.Prema domaćoj klasifikaciji, rendzine su zemljišta sa moličnim A horizontom koji postepeno prelazi u rastresiti karbonatni C horizont. Primarno su karbonatna, i njihova evolucija teče u pravcu izluživanja pa zatim posmeđivanja. Najčešće su pod prirodnom šumskom i travnom vegetacijom, manji deo njih se obraduje. U ovom radu su ispitivane optičke osobine huminskih kiselina zemljišta tipa rendzina, a istraživanja su imala za cilj praćenje posledica izluživanja i promene načina korišćenja ovog tipa zemljišta u Srbiji na stepen humificiranosti huminskih kiselina. Priprema rastvora huminskih kiselina za VIS spektroskopiju izvedena je metodom Kononove. Karakterizacija optičkih osobina huminskih kiselina je data preko optičkih indeksa: E4/E6, ΔlogA i RF. Rezultati su obrađeni u programu StatSoft, Inc. Statistica, Version 8. Proces izluživanja je pozitivno uticao na stepen humificiranosti huminskih kiselina u rendzinama (najveći je pri neutralnoj reakciji). Dalja debazifikacija i acidifikacija izluženih rendzina uticala je negativno, odnosno dovela do smanjenja stepena humificiranosti huminskih kiselina. Stepen humificiranosti huminskih kiselina u karbonatnim rendzinama se kretao travnjak>njiva>šuma, a u izluženim rendzinama njiva>travnjak>šuma. Huminske kiseline karbonatnih rendzina pod šumom i travnjakom su imale veći stepen humificiranosti u poredenju sa izluženim rendzinama pod šumom i travnjakom. U izluženim rendzinama pod njivom stepen humificiranosti huminskih kiselina je bio veći nego u karbonatnim rendzinama pod njivom. Razlike u stepenu humificiranosti huminskih kiselina prema načinu korišćenja koje su se pojavile između karbonatnih i izluženih rendzina ukazuju na dominantan uticaj hemijskih karakteristika zemljišta na osobine huminskih kiselina u poredenju sa količinom i kvalitetom organskih ostataka koji dospevaju u zemljište

Microstructure development and electrical properties of NiO doped alpha-Fe2O3

Poster presented at the 4th Serbian Congress for Microscopy, Belgrade, Serbia, 2010, October 11-12, 201

Influence of rhamnolipids, produced by Pseudomonas aeruginosa NCAIM(P), B001380 on Cr(VI) removal capacity in liquid medium

Pseudomonas aeruginosa NCAIM(P), B001380, a propitious bacterial strain isolated from mineral cutting oil was identified to be chromium tolerant and a producer of biosurfactant rhamnolipid (RL) with potential application in heavy metal bioremediation. Culture growth, RL production and Cr(VI) removal capacity of the strain in the presence of 50 mg L-1 (I) and 100 mg L-1 of Cr(VI) (II) were studied. Maximum of RL production were found in the late-stationary phase at 72 h for both Cr(VI)-amended cultures: I (236 mg L-1) and II (160 mg L-1), as well as the maximum of Cr(VI) removal capacity: 70 % (I) and 57 % (II). The amount of Cr in RL preparation II was 22 mg mg-1 determined by flame atomic absorption spectroscopy (FAAS). Appearance of a new band at 914 cm-1 in infrared (IR) spectrum of RL (II) indicated a significant proof for possible coordination of CrO42-ion with RL. The effect of Cr(VI) on monorhamnolipids (RL1) and dirhamnolipids (RL2) distribution and its ratio were studied by electrospray ionization mass spectrometry (ESI-MS). An increase was observed in a RL2/RL1 ratio for II compared to control

Thermal diffusivity of single crystal Bi0.9Sb0.1

A single crystal Bi0.9Sb0.1 ingot was synthesized using the Bridgman technique. Thermal diffusivity and electronic transport properties of single crystal cleaved plates (00l) were determined from PA photoacoustic phase and amplitude spectra obtained using the photoacoustic method with a transmission detection configuration. Both the PA phase and amplitude were measured versus the modulation frequency and numerically analyzed. EDS analyses done to determine chemical composition of the studied samples as well as to check sample homogeneity. Hall effect measurements data were used for the photoacustic measurements

Polymerase chain reaction in the identification of periodontopathogens: A reliable and satisfactory method?

Aggregatibacter actinomycetemcomitans is considered one of the bacterial species of etiological importance in periodontitis. The aim of this study was to evaluate the serotype of A. actinomycetemcomitans in the subgingival biofilm in subjects with periodontal health and disease. Pooled samples of subgingival plaque were taken for culture-based identification of microorganisms. Colonies suspected to be A. actinomycetemcomitans were selected for molecular identification using either multiplex or conventional PCR in serotype-specific genotyping and 16S rRNA gene sequencing. In silico analysis showed that most selected colonies belong to the genus Campylobacter, although positive signals for serotypes of A. actinomycetemcomitans were obtained with these samples. Identification of A. actinomycetemcomitans by conventional PCR for 16S rRNA with one species-specific and one universal primer was inconclusive because an almost identical signal with Campylobacter gracilis was obtained. Although PCR-based methods for the identification of A. actinomycetemcomitans are more rapid, sequencing should not be omitted

Polymerase chain reaction in the identification of periodontopathogens: A reliable and satisfactory method?

Aggregatibacter actinomycetemcomitans is considered one of the bacterial species of etiological importance in periodontitis. The aim of this study was to evaluate the serotype of A. actinomycetemcomitans in the subgingival biofilm in subjects with periodontal health and disease. Pooled samples of subgingival plaque were taken for culture-based identification of microorganisms. Colonies suspected to be A. actinomycetemcomitans were selected for molecular identification using either multiplex or conventional PCR in serotype-specific genotyping and 16S rRNA gene sequencing. In silico analysis showed that most selected colonies belong to the genus Campylobacter, although positive signals for serotypes of A. actinomycetemcomitans were obtained with these samples. Identification of A. actinomycetemcomitans by conventional PCR for 16S rRNA with one species-specific and one universal primer was inconclusive because an almost identical signal with Campylobacter gracilis was obtained. Although PCR-based methods for the identification of A. actinomycetemcomitans are more rapid, sequencing should not be omitted. [Projekat Ministarstva nauke Republike Srbije, br. 41008 and br. 173048

Radioactivity measurements in soils surrounding four coal-fired power plants in Serbia by gamma-ray spectrometry and estimated dose

The study of spatial distribution of activity concentration of U-238, Ra-226, (210)pb, Th-232, K-40 and Cs-237 radionuclides in the surface soil samples (n = 42) collected in the vicinity of four coal-fired power plants in Serbia is presented. Radioactivity measurements in soils performed by gamma-ray spectrometry showed values [Bqkg(-1)] in the range: 15-117 for U-238, 21-115 for Ra-226, 33-65 for (210)pb, 20-69 for Th-232, 324-736 for K-40, and 2-59 for Cs-137. Surface soil radioactivity that could have resulted from deposition of radionuclides from airborne discharges or resuspension of ash from disposal sites showed no enhanced levels. It was found that variation of soil textural properties, pH values, and carbonate content influenced activity levels of natural radionuclides while radiocesium activities were associated with soil organic matter content. Modification of some soil properties was observed in the immediate vicinity ( lt 1 km) of power plants where the soil was more alkaline with coarser particles (0.2-0.05 mm) and carbonates accumulated. Calculated average values of the absorbed gamma dose rate and annual external effective dose originating from the terrestrial radionudides were 69.4 nGy/h and 0.085 mSv, respectively

Adsorption Efficiency of Cadmium (II) by Different Alkali-Activated Materials

The objective of this study was to demonstrate the potential utilization of fly ash (FA), wood ash (WA), and metakaolin (MK) in developing new alkali-activated materials (AAMs) for the removal of cadmium ions from waste water. The synthesis of AAMs involved the dissolution of solid precursors, FA, WA, and MK, by a liquid activator (Na2SiO3 and NaOH). In concentrated solutions of the activator, the formation of an aluminosilicate gel structure occurred. DRIFT spectroscopy of the AAMs indicated main vibration bands between 1036 cm−1 and 996 cm−1, corresponding to Si-O-Si/Si-O-Al bands. Shifting vibration bands were seen at 1028 cm−1 to 1021 cm−1, indicating that the Si-O-Si/Si-O-Al bond is elongating, and the bond angle is decreasing. Based on the X-ray diffraction results, alkali-activated samples consist of an amorphous phase and residual mineral phases. The characteristic “hump” of an amorphous phase in the range from 20 to 40° 2θ was observed in FA and in all AWAFA samples. By the XRD patterns of the AAMs obtained by the activation of a solid three-component system, a new crystalline phase, gehlenite, was identified. The efficiency of AAMs in removing cadmium ions from aqueous solutions was tested under various conditions. The highest values of adsorption capacity, 64.76 mg/g (AWAFA6), 67.02 mg/g (AWAFAMK6), and 72.84 mg/g mg/g (AWAMK6), were obtained for materials activated with a 6 M NaOH solution in the alkali activator. The Langmuir adsorption isotherm and pseudo-second kinetic order provided the best fit for all investigated AAMs

Assessment of possible association between rs378854 and prostate cancer risk in the Serbian population

Prostate cancer (PCa) is the second most commonly diagnosed cancer among men worldwide. Despite its high incidence rate, the molecular basis of PCa onset and its progression remains little understood. Genome-wide association studies (GWAS) have greatly contributed to the identification of single nucleotide polymorphisms (SNP) associated with PCa risk. Several GWAS identified 8q24 as one of the most significant PCa-associated regions. The aim of this study was to evaluate the association of SNP rs378854 at 8q24 with PCa risk in the Serbian population. The study population included 261 individuals diagnosed with PCa, 257 individuals diagnosed with benign prostatic hyperplasia (BPH) and 106 healthy controls. Data quality analysis yielded results showing deviations from Hardy-Weinberg equilibrium in groups of PCa patients and BPH patients as well as in the control group. There was no significant association between alleles and genotypes of the genetic variant rs378854 and PCa risk in the Serbian population. [Projekat Ministarstva nauke Republike Srbije, br. 173016