Mehanizmi adaptacije strnih žita na kiselost zemljišta

Acid soils limit crop production on 30-40% of the world's arable land and up to 70% of the world's potentially arable land. Over 60% of the total arable lands in Serbia are acid soils. Soil acidity is determined by hydrogen (H+) in soil solution and it is influenced by edaphic, climatic, and biological factors. Major constraints for plant growth on acid mineral soils are toxic concentrations of mineral elements like Al of H+ and/or low mineral nutrient availability due to low solubility (e.g. P and Mo) or low reserves and impaired uptake (e.g. Mg2+) at high H+ concentrations. Aluminum (Al) toxicity is primary factor limiting crop production on acid soils. This review examines our current understanding of mechanisms of Al-toxicity, as well as the physiological and genetic basis for Al-toxicity and tolerance. Inhibition of root growth by Al leads to more shallow root systems, which may affect the capacity for mineral nutrient acquisition and increase the risk of drought stress. Of the two principal strategies (tolerance and avoidance) of plants for adaptation to adverse soil conditions, the strategy of avoidance is more common for adaptation to acid mineral soils. At the same, the short view of the most important genetics tolerance mechanisms, developed and determined in some small grains genotypes, is showed as well.Kisela zemljišta ograničavaju biljnu proizvodnju na 30-40% ukupnih, kao i do 70% potencijalno obradivih svetskih površina. Kisela reakcija ovih zemljišta i nizak sadržaj najvažnijih biljnih hraniva, pre svega R i Sa su ograničavajući faktori postizanja visokih i stabilnih prinosa gajenih biljaka. Pored kisele reakcije, ova zemljišta karakteriše veoma često i povećan sadržaj toksičnih oblika Al, Fe i Mn, kao i nedostatak ili smanjena pristupačnost P, Ca, Mg i nekih mikroelemenata, posebno Mo, Zn i V. Toksičnost Al se smatra najvažnijim faktorom koji ograničava rast biljaka na kiselim zemljištima. Mehanizmi adaptacije strnih žita na kisela zemljišta mogu se podeliti na: spoljašnje, unutrašnje (fiziološke) i genetičke. Dejstvo spoljašnjih mehanizama tolerantnosti zasniva se na imobilizaciji Al u ćelijskom zidu, isticanju Al kroz plazma membranu, uspostavljanju pH barijere u rizosferi i lučenju organskih kiselina, fosfata, helata i drugih liganada korenom u spoljašnju sredinu. Unutrašnji mehanizmi tolerantnosti zasnivaju se na kompleksiranju Al sa proteinima, organskim kiselinama i enzimima, kao i helatiziranju u citoplazmi. Strna žita ispoljavaju različitu tolerantnost prema kiselosti zemljišta i povećanom sadržaju Al u zemljišnom rastvoru. Najosetljiviji je ječam, zatim pšenica, dok veću tolerantnost ispoljavaju ovas, tritikale i raž

Sadržaj i odnos apsorbovanog Ca i Mg u serpentinitskim zemljištima Srbije

The contents of adsorbed Ca and Mg and their ratio (Ca/Mg) were researched in the serpentinite rankers of Serbia. The samples were taken from seven wider locations (Zlatibor, Kopaonik, Miroč, Maljen, Bukovi, Suvobor and Bubanj Potok) in the altitudinal belt between 100 and 1700 m. Altogether 32 soil profiles were opened and 47 soil samples were analyzed. The percentages of adsorbed Ca and Mg were determined by the method of the Atomic Absorption Spectrophotometry, after extraction with NH4-acetate. The study results show that the content of adsorbed Mg-ions in almost all analyzed samples was higher than the percentage of adsorbed Ca-ions, so their ratio (Ca/Mg) is less than 1. This Ca/Mg ratio has an unfavorable impact on the plant development and it was concluded that this is one of the basic reasons of the low productive capacity of the serpentinite rankers in Serbia.U radu su prikazani rezultati istraživanja sadržaja adsorbovanog Ca i Mg kao i njihovog odnosa (Ca/Mg) u serpentinitskim rankerima Srbije. Uzorci su uzeti iz sedam širih lokacija (Zlatibor, Kopaonik, Miroč, Maljen, Bukovi, Suvobor i Bubanj Potok) u visinskom pojasu između 100 i 1700 m nad.visine. Ukupno su otvorena 32 pedološka profila i analizirano je 47 uzoraka zemljišta. Sadržaj apsorbovanog Ča i Mg određen je metodom atomske aprsorpcione spektrofotometrije, posle ekstrakcije sa NH4-acetatom. Rezultati istraživanja su pokazali da je skoro u svim ispitanim uzorcima sadržaj apsorbovanog Mg-jona veći od sadržaja apsorbovanog Ca-jona, te je i njihov odnos (Ca/Mg) manji od jedinice. Ovakav odnos Ca/Mg se nepovoljno odražava na uspevanje biljaka i smatramo da je jedan od osnovnih uzroka niske produktivne sposobnosti serpentinitskih rankera Srbije

Uticaj ekstrakta rizoma i korena kukureka (Helleborus odorus W. et K.) na parametre bele krvne slike i stepen fagocitoze kod wistar pacova

The objective of this research was to study the effects that the extract of rhizome and root of Helleborus odorus W. et K. (Ranunculaceae) can have on modifications in the parameter values of white blood cells count and degree of phagocytosis by peritoneal macrophages and neutrophil granulocytes in Wistar rats. The trial was conducted on 28 rats divided into 4 groups with 7 animals in each group. To the control group of rats sterile physiological solution in the quantity of 0.25 mL/100 g BW was applied intramuscularly. For the purpose of monitoring the effect of the extract of rhizome and root of hellebore (HE) during a time period, the HE was applied intramuscularly to rats in a dose of 10 mg/100 g BW, while the blood samples for analysis were taken after 24h, 48h and 72h. The consequence of intramuscular application of HE was an increased count of total leukocytes in all trial groups, the most expressed leukocytosis being registered 24h after application of HE. Statistically significant higher value in the count and percent of neutrophil granulocytes in the blood was recorded 24h after treatment in relation to the control and two other trial groups (p lt 0.001), among which a statistical significance was not established. The extract of hellebore rhizome and root has led to lymphopenia, resulting in the increase of the neutrophil/limphocyte index in the trial groups 24h and 48h after treatment. The application of HE had no significant effect on the count of monocytes in treated animals. The applied extract has caused a significant increase in the degree of phagocytosis by residing peritoneal macrophages and neutrophil granulocytes in blood.Cilj ovog rada je bio da se ispita uticaj ekstrakta rizoma i korena H. odorus W. et K. na promenu vrednosti parametara bele krvne slike i stepen fagocitoze od strane peritonealnih makrofaga i neutrofilnih granulocita kod pacova soja Wistar. Ogled je izveden na 28 pacova podeljenih u 4 grupe po 7 jedinki. Kontrolnoj grupi pacova je intramuskularno aplikovan sterilan fiziološki rastvor u količini od 0,25 ml/100 g TM. U cilju praćenja efekta ekstrakta rizoma i korena kukureka (EK) u toku vremena, pacovima je intramuskularno aplikovan EK u dozi od 10mg/100g TM, a krv za analizu je uzimana posle 24h, 48h i 72h. Intramuskularna aplikacija EK imala je za posledicu povećanje broja ukupnih leukocita u svim oglednim grupama, pri čemu je najizraženija leukocitoza registrovana 24h nakon aplikovanja EK. Statistički značajno veća vrednost broja i procenta neutrofilnih granulocita u krvi zabeležena je 24h posle tretmana u odnosu na kontrolnu i ostale dve ogledne grupe (p lt 0,001), između kojih nije utvrđena statistička značajnost. Ekstrakt rizoma i korena kukureka doveo je do nastanka limfopenije, što je imalo za posledicu povećanje neutrofilno/limfocitnog indeksa u oglednim grupama 24h i 48h nakon tretmana. Aplikacija EK nije značajno uticala na broj monocita kod tretiranih životinja. Upotrebljeni ekstrakt doveo je do značajnog povećanja stepena fagocitoze od strane rezidentnih peritonealnih makrofaga i neutrofilnih granulocita krvi

Effects of nerve and fibroblast growth factors on the production of nitric oxide in experimental model of Huntington's disease

The role of nitric oxide (NO) in neurological diseases represents one of the most studied, yet controversial subjects in physiology. The aim was to examine the effects of intrastriatal injection neurotrophins (nerve growth factors-NGF, fibroblast growth factors-FGF) in order to investigate the possible involvement of NO in quinolinic acid (QA) induced striatum toxicity in the rat model of Huntington's disease (HD). QA was administered unilaterally into the striatum of adult Wistar rats in a single dose of 150 nM. The other two groups of animals were pretreated immediately before QA application with NGF and FGF, respectively. Control group was treated with 0.9% saline solution in the same manner. Animals were decapitated 7 days after the treatment. Nitrite levels were significantly decreased both in the ipsi- and contra lateral striatum and forebrain cortex of NGF- and FGF-treated animals compared with QA treatment. These results indicated a temporal and spatial propagation of oxidative stress and spread protective effects of NGF and FGF on the forebrain cortex, the distant structure, but tightly connected with striatum, the place of direct neurotoxin damage. Neurotrophins could be the potential neuroprotective agents in HD

Sinteza i koroziono ponašanje polianilina na mekom čeliku, bakru i aluminijumu iz benzoatnih rastvora

The electrochemical synthesis of polyaniline (PANI) on mild steel, aluminum and copper from the sodium benzoate solutions has been investigated. It has been shown that thin, highly adherent, polyaniline films on the investigated metals could be obtained by anodic oxidation with current densities in the range of 0.5 and 1.5 mA cm-2. The corrosion behavior of mild steel, aluminum and copper with polyaniline coating in 0.5 mol dm3 NaCl (pH 3) solutions, has been investigated by polarization technique. The corrosion current densities, porosity and protection efficiency was determined. It has been shown that polyaniline coating provided corrosion protection of all mentioned metals.U radu je ispitivana elektrohemijska sinteza polianilina (PANI) na mekom čeliku, aluminijumu i bakru iz rastvora natrijum-benzoata i monomera anilina. Ustanovljeno je da se tanki, dobro adherentni, filmovi polianilina mogu formirati na svim ispitivanim metalima pri anodnim gustinama struja od 0,5-1,5 mA cm-2. Ispitivano je koroziono ponašanje metala sa prevlakom polianilina u rastvoru 0,5 mol dm-3 NaCl (3%). Ustanovljeno je da ove prevlake pružaju korozionu zaštitu svim ispitivanim metalima u datoj korozionoj sredini

Solution of general and prevention of ecological problems of Stara Planina Mountain as potential obstacles to the development of rural tourism

The development of rural tourism positively affects the economic development of rural communities, but the very pace of its development often results in negative effects on the environment. Uncontrolled rural tourism development, without an adequate planning system, can greatly endanger the entire ecosystem of a destination. The aim of this paper is to determine how much the development of rural tourism on Stara Planina Mountain depends on the solution of general and prevention of ecological problems. A method that allows the cause-effect relationships between these phenomena is a linear regression analysis. This analysis best describes the quantitative dependence between the variations of the observed phenomena in real conditions. It represents the means that enable us to evaluate and predict the values of the dependent variable for the desired values of the explanatory variable. In other words, the main issue is rural tourism on Stara Planina Mountain, which depends on the solution of general and prevention of environmental problems

The effects resulting from the application of the concept of the sustainable development of rural tourism on Stara planina

The development of rural tourism on Stara planina (Old Mountain) has a positive impact on the economic development of the local communities in the area. However, if an adequate program of the sustainable development of tourism on Stara planina were made, that would also have positive effects as an accompanying factor contributing to the development of rural tourism. In particular, the results would show that there is a need for the preservation of the quality of the environment and the development of all resources, especially with respect to the realization of an economic profit. The aim of the paper is to detect the extent to which the effects arising from the development of rural tourism depend on the implementation of the program of the sustainable tourism development of the mountain. The method that makes the realization of a causal connection between these two phenomena possible is the linear regression analysis. The purpose of the regression analysis is to determine the shape of such a connection, i.e. the dependence between the observed phenomenon, by applying a mathematical formula and a range of corresponding assumptions. Therefore, it best describes the quantitative relationship between the variation in the observed phenomenon of reality, as well as the agent that serves to evaluate the predictive value and the dependent variable against the desired value of the explanatory variables or the effects resulting from the development of rural tourism on Stara planina

Enhancing the nuclear security on nuclear research reactors RA and RB

VI International Conference on Radiation in Various Fields of Research : RAD 2018 : book of abstracts; June 18-22, 2018; Ohrid, Macedoni

Pentoxifylline Prevents Autoimmune Mediated Inflammation in Low Dose Streptozotocin Induced Diabetes

Xanthine derivative, pentoxifylline (PTX), has been recently shown to exert a protective effects in certain animal models of autoimmunity, including diabetes in NOD mice. In the present study, the immunomodulatory potential of PTX was investigated in autoimmune diabetes induced by multiple low doses of streptozotocin (MLD-SZ) in genetically susceptible CBA/H mice (tested with 40 mg SZ/kg b.w. for 5 days) and DA rats (tested with 20 mg/kg b.w. for 5 days). In both species, 2 – 3 weeks following the MLD-SZ treatment, sustained hyperglycemia developed, as an outcome of inflammatory reaction with endothelial cell activation and accumulation of mononuclear cells. Although there was no evidence of typical insulitis in early disease development (day 10), in both rats and mice, macrophages, CD4+ and CD8+ cells were present in the islets of Langerhans as diffuse mononuclear infiltrates with the expression of IFN-γ and inducible NO synthase (iNOS). Administration of PTX (200 mg/kg/day for 10 days) in combination with MLD-SZ reduced insulitis and the production of mediators tested, and prevented the development of hyperglycemia. These results suggest that beneficial effects of PTX involve down-regulation of local proinflammatory cytokine-mediated NO synthase pathway. They also demonstrate that in addition to ameliorating spontaneous autoimmunity in NOD mice, PTX may be effective in downregulating an inflammatory autoimmune process triggered in susceptible host by an external agents, such as streptozotocin

Spectral analysis of eeg signal in verbal information processing task

The EEG is a non-invasive method to obtain information about neural activity associated with cognitive processes. Its great temporal resolution can provide data regarding the process itself within milliseconds but EEG has poor spatial resolution. The EEG is based on the voltage difference between two (or more) electrodes and represents the summation of numerous neuron activity. The objective of the study reported was to analyze the EEG signal in verbal information processing task using spectral analysis for frequency band and power spectrum extraction. Also we wanted to determine relation between different frequency bands (Theta – θ, Beta – β and Alpha - α) and their power spectrum in different parts of the task (perception, retention and reproduction) for different stimuli (syllables, words, non-words, sentences, picture situations and picture stories). The sample comprised of 9 subjects, right-handed, native speakers of Serbian language with no history of hearing and speech-language disorders. All subjects were not using any medication that may influence EEG signal. After the standard procedure of EEG electrodes placement, subjects listened to a set of auditory presented verbal stimuli. After each stimulus they had a 2 second retention period time followed by a reproduction period. They were given 5 seconds for viewing picture situations and a 15 second period for the picture story followed by a reproduction period. Differences between EEG frequency bands and power as well as their cortical representation in verbal information processing task will be discussed