The impact of geological substrate on the metal content in plants

Geološka podloga i na njoj nastala zemljišta, kao skup ekoloških faktora utiču na divergenciju biljnih oblika i vegetacijskih jedinica. Pored hemijskog sastava geološke podloge, na vegetaciju koja se na njoj razvija, značajan uticaj imaju fizička struktura i kvantitativan odnos pojedinih elemenata i njihovih soli u podlozi, što se naročito lepo može videti pri komparaciji vegetacija nastalim na različitim geološkim podlogama i zemljištima, kao i komparativnim upoređivanjem hemijskog sadržaja njihovih predstavnika. Biološki monitoring podrazumeva primenu živih organizama kao bioindikatora promena u životnoj sredini u prostoru i vremenu. Biljke su dobri indikatori, obzirom da su prilagođene na specifična svojstva zemljišta i geološke podloge svojim morfo-fiziološkom adaptacijama, i mogu da posluže za utvrđivanje hemijskog statusa određenog mesta ili oblasti. Ova doktorska disertacija se bavi problematikom uticaja geološke podloge i zemljišta koja su se formirala na određenom tipu podloge na sadržaj metala u biljkama. Ciljevi ove disertacije fokusirani su na pitanja sadržaja ispitivanih elemenata u zemljištu i biljkama koje rastu na različitim geološkim podlogama, kao i na ukazivanje koje biljne vrste, rodove i familije možemo koristiti kao dobre indikatore i hiperakumulatore prisustva određenih metala, kao i mogućnosti bioremedijacije zemljišta opterećenih povećanim koncentracijama određenih, naročito teških metala, što doprinosi praktičnoj primeni dobijenih naučnih rezultata. Istraživano područje obuhvata lokalitete koji se nalaze na različitim geološkim podlogama serpentinitu, krečnjaku, andezitu i pesku, i to pet lokaliteta sa serpentinskom geološkom podlogom (jedan od lokaliteta je na jalovištu azbesta), i po jedan sa krečnjačkom, andezitnom i peskom kao geološkom podlogom. Nastanak i formiranje zemljišta na ovim geološkim podlogama je različito i specifično, tako da uslovljava pojavu osobene flore i vegetacije. Prikupljeno je 40 različitih biljnih vrsta u okviru 100 uzoraka biljaka, obzirom da su neke vrste uzorkovane sa više od jednog lokaliteta. Određivane su koncentracije jedanaest metala (kalcijum, magnezijum, gvožđe, mangan, bakar, cink, nikl, olovo, kadmijum, kobalt i hrom) u zemljištu i uzorcima pripremljenim od celih biljaka. Sadržaji ispitivanih metala u zemljištu varirali su u zavisnosti od vrste metala i prirode geološke podloge na kome je zemljište nastalo, a srednje vrednosti sadržaja ispitivanih elemenata u zemljištu imale su poredak: Mg>Fe>Ca>Ni>Mn>Cr>Co>Zn>Pb>Cu>Cd. Serpentinska zemljišta, kao i zemljište nastalo na krečnjačkoj geološkoj podlozi sadržala su Ni i Cr iznad granične vrednosti, vrednosti koju propisuje Evropska unija i maksimalno dozvoljenih koncentracija propisanih za zemljišta. Zemljišta nastala na serpentinskoj geološkoj podlozi sadrže Ni i Cr iznad remedijacione vrednosti. Takođe, na svim serpentinskim lokalitetima, kao i na krečnjačkom lokalitetu utvrđene su koncentracije Co i Cd u zemljištu više od propisane granične vrednosti, a koncentracije Co su više i od njegove srednje vrednosti utvrđene za zemljišta širom sveta. Sadržaj ispitivanih elemenata u biljkama bio je promenljiv, i zavisio je od biljne vrste, vrste metala i prirode geološke podloge sa koje su biljke uzorkovane, a srednja vrednost sadržaja ispitivanih elemenata u biljkama imala je poredak: Ca>Mg>Fe>Ni>Mn>Cr>Zn>Cu>Co>Pb>Cd. Hemijska analiza i utvrđivanje hemijskog statusa biljaka jedna je od metoda kojom se analiziraju hemijska svojstva i promene u biosferi. Reakcija biljaka na hemijski stres koji uzrokuje disbalans elemenata (bilo nedostatak ili suvišak elementa), ne može se jasno definisati zato što biljke razvijaju tokom njihove evolucije, ontogenetskog i filogenetskog života nekoliko biohemijskih mehanizama koji rezultiraju u adaptaciji i toleranciji biljaka na potpuno novu ili životnu sredinu u kojoj postoji hemijski disbalans. Biljke pokazuju promenljivost i nekada specifičnu sposobnost da absorbuju elemente iz zemljišta, a mera usvajanja elemenata od strane biljaka zavisi od njihove pojedinačne sposobnosti, tako da su utvrđene velike razlike u sposobnosti usvajanja metala između različitih vrsta i genotipova biljaka. Od 40 biljnih vrsta koje su bile uključene u istraživanje, kod 32 vrste su utvrđeni biološki apsorpcioni koeficijenti veći od jedinice za 7 različitih elemenata. Biološki apsorpcioni koeficijent veći od jedinice za Cu pokazale su 22 biljne vrste; 21 vrsta za Zn; 7 za Ni; 5 za Mn; 2 za Cr i po jedna za Pb i Mg. Vrste Alyssum markgrafii i Alyssum murale su hiperakumulatori Ni (na serpentinskom lokalitetu selo Kamenica vrsta Alyssum murale je akumulirala skoro 4 puta više Ni, a endemična hiperakumulatorska vrsta Alyssum markgrafii na serpentinskom lokalitetu Kamenjar je akumulirala 3 puta više Ni od referentne hiperakumulatorske vrednosti). Istraživanja ove disertacije su pokušala sa razjasne pitanja uticaja geološke podloge na sadržaj nekih elemenata u biljkama, ulogu i značaj biljaka u njihovoj akumulaciji, kao i da sugeriše koje su biljne vrste dobri indikatori, hiperakumulatori i test vrste koje se mogu koristiti u bioremedijaciji, sve u cilju praćenja, zaštite i restauracije proučavanih ekosistema.Geological background and lands that it generated, as a set of environmental factors affect the divergence of plant forms and vegetation units. In addition to the chemical composition of the geological substrate, physical structures and quantitative relationship of individual elements and their salts in the substrate have a significant impact on vegetations that develop on that substrate, which is particularly well be seen when comparing the vegetation generated on different bedrocks and soils, as well as by comparative comparison of the chemical content of their representatives. Biological monitoring involves the use of living organisms as bio-indicators of environmental change, in space and time. Plants are good indicators, as they are adapted to the specific characteristics of soil and geological substrate by their morpho-physiological adaptations, and can be used to determine the chemical status of a particular place or region. This dissertation deals with issues of the impact of geological substrates and soils, which are formed on a specific type of substrate to the metal content in plants. The aims of this dissertation focused on the question of the content of analyzed elements in soil and plants that grow on different geological substrates, as well as to highlight which plant species, genera and families can be used as good indicators and hyperaccumulators of the presence of certain metals, as well as the possibility of bioremediation of land burdened by increased concentrations of certain, particularly heavy metals, which contributes to the practical application of the scientific results obtained. The studied area includes sites that are located on different geological substrates, serpentinite, limestone, andesite and sand, where five sites was with serpentine geological substrate (one of the sites is on the asbestos tailings), and other ones with limestone (1), andesite (1) and sand (1) as the geological background. The genesis and soil formation on these geological substrates is different and specific, so that it leads to appearance of distinctive flora and vegetation. It was collected 40 different plant species in the scope of 100 samples of plants, with the respect that some species were sampled on more than one site. The concentrations of eleven metals (calcium, magnesium, iron, manganese, copper, zinc, nickel, lead, cadmium, cobalt and chromium) in the soil samples and samples prepared from whole plants were determined. In the soil, concentrations of metals analyzed varied depending on the type of metal mean values of element content in the soil had the next order: Mg>Fe>Ca>Ni>Mn>Cr>Co>Zn>Pb>Cu>Cd. Serpentine soils, as well as the soil developed on limestone bedrock contained Ni and Cr above the limit value, the value set by the European Community, and the maximum allowed levels prescribed for the land. Soils formed on serpentine substrate contain Ni and Cr above remediation value. Also, at all serpentine sites, as well as at limestone location, the concentrations of Co and Cd in the soil were more than the prescribed limits, and Co concentrations were higher than its mean value determined for the land around the World. Content of elements investigated in plants was variable and depended on the plant species, type of metal and the nature of the geological substrate from which plants were sampled, and the mean value of the element content in plants had the order: Ca>Mg>Fe>Ni>Mn>Cr>Zn>Cu>Co>Pb>Cd. Chemical analysis and determination of the chemical status of plants is one of the methods used to analyze the chemical properties and changes in the biosphere. The reaction of plants on the chemical stress, which imbalance of elements causes (either deficiency or excess of elements) can not be clearly defined because the plants develop several biochemical mechanisms during their evolution, ontogenetic and phylogenetic lives that result in adaptation and tolerance of plants to a whole new environment or environment where a chemical imbalance exists. Plants show variability and sometimes specific ability to absorb elements from the soil, and measure of that adoption of the elements depends on their individual ability, so the great differences in the ability of metal assimilation among different species and genotypes of plants were determined. Of the 40 plant species that were included in the study, at 32 species biological absorption coefficient were greater than one for 7 different elements. Biological absorption coefficient greater than one for Cu 22 species showed; 21 species for Zn, 7 for Ni, 5 for Mn, 2 for Cr and one for Pb and Mg, too. Species Alyssum markgrafii and Alyssum murale are hyperaccumulators of Ni (at the serpentine locality Kamenica village species Alyssum murale accumulated Ni nearly 4 times more, and endemic hyperaccumulator species Alyssum markgrafii on the serpentine locality accumulated Ni 3 times more than the reference hyperaccumulator value). The researches included in this dissertation attempted to clarify the influence of geologic substrate on the content of some elements in plants, the role and importance of plants in their accumulation, as well as to recommend the plants, which are good indicators, hyperaccumulators and test species that can be used in bioremediation for the purpose of monitoring, protection and restoration of ecosystems examined

Značaj oksidativnog stresa i poremećaja metabolizma arginina kao markera metastaziranja tumora debelog creva

Colorectal cancer is one of the most frequent human malignant diseases and one of the most common causes of malignant diseases death. Oxidative and nitrosative stress have an important role in cancer initiation and propagation. That is why this study is focused on the determination of oxidative and nitrosative stress markers in tumor, adjacent and health tissue, which are important for estimation of tumor proliferative and angiogenic potential and assessment of their validity in identification of patients’s risk for tumor process promotion and distant metastasis development. The study encompassed 50 patients who underwent surgery due to colorectal cancer. In the tissue samples from resected preparation (tumor, adjacent and healthy tissue, at least 10 cm distant from tumor), oxidative and nitrosative stress markers, malondyaldehyde and nitric oxide (NO), as well as superoxide dismutase activity, were determined. Also, arginase activity and asymmetric (ADMA) and symmetric (SDMA) dimethylarginines, as potent modulators of NO synthesis, were determined. The biochemical parameters were correlated with the tumor recurrence, metastasis and three year- and five year survival. The results of this multidsiciplinary study prove the presence of oxidative stress in tumor tissue. Lower NO concentrations in tumor tissue compared to the adjacent tissue point out high angiogenic potential, which could have clinical importance in the assessment of the probability of local recurrence. Increased ADMA and SDMA concentrations in tumor tissue associated with low NO levels, make the basis for the new therapeutic strategies directed to the use of inhibitors of their synthesis as ideal candidates for molecular threrapy of colorectal cancer. ADMA concentration in adjacent tissue was proved to be an independent predictor of distant metastasis. The obtained results point out that determination of examined biomarkers in colorectal cancer tissue samples, after surgery, could give useful informations about tumor proliferative and angiogenic potential in patients, which could enable individualization of therapy and the choice of adequate adjuvant therapy

Phytoaccumulation of metals in three plants species of the Asteraceae family sampled along a highway

The aim of this study was to determine the ability of roots and above-ground parts of three plant species of the Asteraceae family (Matricaria inodora L., Achillea millefolium L., Crepis setosa Haller fill.) for bioaccumulation and translocation of eight metals (Ca, Mg, Fe, Mn, Cu, Zn, Pb, Cr). Those plants were sampled directly along the lanes of the highway at the entrance into the City of Kragujevac, Republic of Serbia. The investigated metals are emitted into the air from road traffic and are deposited in the surrounding soil. Many of them are toxic to the living organism, and it is, therefore, necessary to apply effective, economical, sustainable methods for their removal from the environment. An example of such a method is as phytoremediation, based on the use of metal hyperaccumulator plants. The results of this research showed the species studied differ in the absorption, translocation and accumulation of investigated metals. They also showed that species M. inodora and A. millefolium (leaves) can be used for the phytoextraction of Ca, Mg, Fe, Mn, Cu, Zn and Cr, species C. setosa (leaves) for Ca, Mg and Cu species M. inodora (stem) for Cr. The results further indicate that all three species absorb Zn from the soil and translocate it to the stems and leaves. All three of the studied species are suitable for phytostabilization of soils loaded with Zn, but only the species M. inodora and C. setosa can be applied in phytoremediation of this metal.&nbsp

Immortelle (Xeranthemum annum L.) as a natural source of biologically active substances

Antioxidant and antimicrobial effects, total phenolic content and flavonoid concentrations of methanolic, acetone and ethyl acetate extracts from Xeranthemum annuum L. were investigated in this study. The total phenolic content was determined using Folin-Ciocalteu reagent and ranged between 101.33 to 159.48 mg GA/g. The concentration of flavonoids in various X. annuum extracts was determined using spectrophotometric method with aluminum chloride and the results varied from 22.25 to 62.42 mg RU/g. Antioxidant activity was monitored spectrophotometrically using DPPH reagent and expressed in terms of IC50 (μg/ml), and it ranged from 59.25 to 956.81 μg/ml. The highest phenolic content and capacity to neutralize DPPH radicals were found in the acetone extract. In vitro antimicrobial activity was determined by microdilution method. Minimum inhibitory concentration (MIC) and minimum microbicidal concentration (MMC) have been determined. Testing was conducted against 24 microorganisms, including 15 strains of bacteria (standard and clinical strains) and 9 species of fungi. Statistically significant difference in activity between the extracts of X. annuum L. was observed and the acetone extract was found most active. The activity of acetone extract was in accordance with total phenol content and flavonoid concentration measured in this extract. The tested extracts showed significant antibacterial activity against G+ bacteria and weak to moderate activity against other microorganisms. Based on the obtained results, X. annuum can be considered as a rich natural source of polyphenolic compounds with very good antioxidant and antimicrobial activity

Molecular characterization of red clover genotypes utilizing microsatellite markers

Genetic resources of red clover (Trifolium pratense L.) are the basis for the improvement of this important forage legume. The objective of this study was microsatellite characterization of the accessions from the collection of the Institute of Field and Vegetable Crops in Novi Sad, Serbia. Molecular evaluation of 46 red clover genotypes was performed by applying the set of 14 primer pairs of microsatellite markers. These primer pairs amplified a total of 187 alleles, with an average of 13.36 alleles per locus and average polymorphism information content (PIC) value was 0.306. The minimum values of Dice genetic distances based on polymorphism of microsatellite markers were found among genotypes NCPGRU2 and NCPGRU5 (0.311) and the highest values of genetic distances were determined for a couple of genotypes Violeta and BGR2 (0.933). The average genetic distance between all pairs of genotypes amounted 0.587. The results of the principal coordinate analysis (PCoA) were consistent with the results obtained on the basis of cluster analysis, except that the PCoA allocated another four genotypes. There was no relationship between groups of genotypes formed by the use of cluster analyses and PCoA with their geographical origin. Analysis of molecular variance of 46 red clover genotypes by the status and ploidy level was significant, but it also suggested a weak genetic differentiation of groups formed on the basis of those characteristics. Observed groups of genotypes, according to the cluster analyses and PCoA of microsatellite data, could be used in future breeding programs for the selection of germplasm

Genetic diversity of alfalfa domesticated varietal populations from Libyan genbank revealed by RAPD markers

Alfalfa (Medicago sativa L.) is an important forage legume in Libya. The genetic diversity of nine alfalfa domesticated varietal populations was studied using thirteen RAPD primer combinations. The number of polymorphic fragments detected per primer combination ranged from 8 to 46 bands with an average of 24 bands. The number of polymorphic bands detected was from 6 (Atalia population) to 37 (Gabsia population). The lowest genetic distance was 0.058 and the highest was 0.655. The average genetic distance was (0.356). The dendrogram based on Ward's minimum variance clustering method grouped the nine populations into the two main clusters. The first group included Fazania, Atalia, Masratia, Zawia, Denamo Ferade and Arezona. The second group was composed of Tagoria, Gabsia and Wade Alrabeh. The simplicity of RAPD assays for detection of genetic polymorphisms is confirmed in our study, and results can be utilized in breeding practice

A hybrid wim implementation strategy

Road authorities often have limited or no reliable information on the actual traffic loading on their road network. When starting to implement WIM systems on a national road network – and assuming limited financial means – one of the key questions is: “Where to start? This presentation will describe a new approach for the implementation of Weigh-InMotion (WIM) systems on a road network using a combination of different WIM technologies. First a series of short term (2 weeks) Bridge-WIM measurements will be used to identify actual overloading hot-spots on the road network prior to investing in the installation of more costly, permanent In-Road WIM systems. This hybrid approach is especially suited for countries where no or limited reliable information is available on the actual distribution of traffic (over-)loading. The approach has been used as part of the implementation strategy for WIM implementation in the republics of Serbia and Georgia in Europe.Papers presented at the 40th International Southern African Transport Conference on 04 -08 July 202

Sinteza vlakana magnezijum-oksida i magnezijum-hidroksida korišćenjem paukove mreže kao matrice

Spider silk fibers, collected from Pholcus Phalangioides spider were used as a template for obtaining magnesium oxide (MgO, periclase) as well as magnesium hydroxide (Mg(OH)2, brucite) fibers. Magnesium oxide fibers were obtained in a simple manner by heat induced decomposition of magnesium salt (MgCl2) in the presence of the spider silk fibers, while magnesium hydroxidefibers were synthesized by hydration of MgO fibers at 50 °C, 70°C and 90 °C, for 48 and 96 h. According to Scanning electron microscopy (SEM), dimensions of spider silk fibers determined the dimension of synthesized MgO fibers, while for Mg(OH)2 fibers, the average diameter was increased with prolonging the hydration period. The surface of Mg(OH)2 fibers was noticed to be covered with brucite in a form of plates. X-ray diffraction (XRD) analysis showed that MgO fibers were single-phased (the pure magnesium oxide fibers were obtained), while Mg(OH)2 fibers were two- or single-phased brucite depending on incubation period, and/or incubation temperature.Vlakna paukove mreže sakupljena od Pholcus phalangioides pauka korišćena su kao matrica za dobijanje vlakana magnezijum oksida (MgO, periklas) i magnezijum-hidroksida (Mg(OH)2, brucit). Vlakna magnezijum oksida jednostavno su dobijena termičkim razlaganjem soli magnezijuma (MgCl2) u prisustvu vlakana paukove mreže, dok su vlakna magnezijum hidroksida sintetisana hidratacijom MgO vlakana na temperaturama: 50, 70 i 90 °C u trajanju od 48 i 96 h. Na osnovu rezultata skenirajuće elektronske mikroskopije (SEM), veličina sintetisanih MgO vlakana bila je određena dimenzijama vlakana pauka, dok je za Mg(OH)2 vlakna prosečan dijametar rastao sa produženjem perioda hidratacije. Na površini Mg(OH)2 vlakana uočeni su tabličasti kristali brucita. Difrakcija X zraka (XRD) pokazala je da su vlakna periklasa jednofazna (dobijen je čist magnezijum-oksid), dok su brucitna vlakna bila dvofazna ili jednofazna, u zavisnosti od inkubacionog perioda i/ili teperature na kojoj je vršena inkubacija

A fluorescent nanoprobe for single bacterium tracking: functionalization of silver nanoparticles with tryptophan to probe the nanoparticle accumulation with single cell resolution

The investigation of the interaction of silver nanoparticles and live bacteria cells is of particular importance for understanding and controlling their bactericidal properties. In this study, the process of internalization of silver nanoparticles in Escherichia coli cells was followed by means of synchrotron excitation deep ultraviolet (DUV) fluorescence imaging. Antimicrobial nanostructures that can absorb and emit light in the UV region were prepared by functionalization of silver nanoparticles with tryptophan amino acid and used as environmentally sensitive fluorescent probes. The nanostructures were characterized by morphological (TEM) and spectroscopic methods (UV-vis, FTIR, XPS, and photoluminescence). The TEM images and the analyses of the UV-vis spectra suggested that the addition of tryptophan led to the formation of hybrid nanostructures with pronounced eccentricity and larger sizes with respect to that of the initial silver nanoparticles. The DUV imaging showed that it was possible to distinguish the fluorescent signal pertaining to silver-tryptophan nanostructures from the autofluorescence of the bacteria. The spatial resolution of the fluorescence images was 154 nm which was sufficient to perform analyses of the accumulation of the nanostructures within a single bacterium. The DUV imaging results imply that the tryptophan-functionalized silver nanoparticles interact with cell membranes via insertion of the amino acid into the phospholipid bilayer and enter the cells

A large-scale test of the link between intergroup contact and support for social change

Guided by the early findings of social scientists, practitioners have long advocated for greater contact between groups to reduce prejudice and increase social cohesion. Recent work, however, suggests that intergroup contact can undermine support for social change towards greater equality, especially among disadvantaged group members. Using a large and heterogeneous dataset (12,997 individuals from 69 countries), we demonstrate that intergroup contact and support for social change towards greater equality are positively associated among members of advantaged groups (ethnic majorities and cis-heterosexuals) but negatively associated among disadvantaged groups (ethnic minorities and sexual and gender minorities). Specification-curve analysis revealed important variation in the size—and at times, direction—of correlations, depending on how contact and support for social change were measured. This allowed us to identify one type of support for change—willingness to work in solidarity— that is positively associated with intergroup contact among both advantaged and disadvantaged group members