Screening of drought oxidative stress tolerance in Serbian melliferous plant species

This study was designed to examine and compare antioxidant and free-radical scavenging activities of leaves of six different melliferous plant species (Populus alba, Robinia pseudoacacia, Sophora japonica, Euodia hupehensis, Tilia sp., Fraxinus sp.) from Serbia in order to evaluate their drought oxidative stress tolerance. Experiment was conducted during June, July and August. In this study, we reported the results concerning proline accumulation, soluble protein content, quantities of malonyldialdehyde,total antioxidant capacity determined by FRAP method and scavenger activity determined by DPPH method. According to our results, all melliferous plant species were subjected to drought oxidative stress during July when soil humidity decreased. During July, proline content and MDA quantity increased and soluble proteins decreased in all investigated species. High and permanent antioxidant activity during the whole investigated period was observed in P. alba, but insufficient to protect itsleaves from oxidative injury during the period of drought in July. The highest ability to accumulate proline and highest protein content under severe drought stress in July was observed in Fraxinus sp. Other investigated antioxidant parameters (total antioxidant and DPPH radical scavenger capacities) were high and accumulation of MDA was low which indicate high drought oxidative stress tolerance. Therefore, highest ability to adapt under severe drought stress and highest drought oxidative stresstolerance were observed in Fraxinus sp.Key words: Melliferous trees, lipid peroxidation, DPPH, FRAP, proline accumulation

Tending operation models for white poplar (Populus alba L.) stands growing under sandy soil conditions

Integrated research aimed to intensify the practices of afforestation especially of white poplar and grey poplar woods. A new, simplified tending procedure has been developed to substitute earlier models considering the target diameter by right spacing as a tool to achieve adequat quality of logs. The practice-oriented model may help the qualitative improvement of white poplar growing technology in Hungary as well as in Serbia

Tending operation models for white poplar (Populus alba L.) stands growing under sandy soil conditions

Integrated research aimed to intensify the practices of afforestation especially of white poplar and grey poplar woods. A new,simplified tending procedure has been developed to substitute earlier models considering the target diameter by right spacing as a tool toachieve adequat quality of logs. The practice-oriented model may help the qualitative improvement of white poplar growing technology inHungary as well as in Serbia

Deposit Formation in the Holes of Diesel Injector Nozzles: A Critical Review

Current developments in fuels and emissions regulations are resulting in increasingly severe operating environment for the injection system. Formation of deposits within the holes of the injector nozzle or on the outside of the injector tip may have an adverse effect on overall system performance. This paper provides a critical review of the current understanding of the main factors affecting deposit formation. Two main types of engine test cycles, which attempt to simulate field conditions, are described in the literature. The first type involves cycling between high and low load. The second involves steady state operation at constant speed either at medium or high load. A number of influences on the creation of deposits are identified. This includes fouling through thermal condensation and cracking reactions at nozzle temperatures of around 300°C. Also the design of the injector holes is an influence, because it can influence cavitation. The implosion of cavitation bubbles is believed to limit nozzle deposits. Field and laboratory tests showed that small amounts (around 1ppm) of zinc tend to increase the formation of deposits and are therefore another influence. But it is not clear whether zinc acts catalytically to accelerate deposit formation or if it becomes part of the solid deposits. Bio-diesel has been observed to lead to higher deposit formation in the injector nozzle. The chemical and physical processes that lead to deposit formation are not known or well understood, due to their complexity. A physical mechanism put forward focuses on the role of the residual fuel that remains in the nozzle holes after the end of the injection process. © 2008 SAE International

The Role of Transformation in Learning and Education for Sustainability

Education research has acknowledged the value of transformation, which offers an opportunity for researching and rethinking how appropriate and successful educational practices may be. However, despite the role of transformation in higher education and particularly in sustainability learning, there is a paucity of studies which examine the extent to which transformation and learning on matters related to sustainable development may be integrated. Based on this perceived research need, the purpose of this article is to present how transformation in learning in education for sustainability requires the commitment of Faculty and the engament of students. To do this, a set of qualitative case studies were used in higher education institutions across seven countries (Brazil, Serbia, Latvia, South Africa, Spain, Syria, UK). The findings revealed that the concept of education for sustainable development has not been sufficiently integrated into the concept of transformation in higher education institutions. It also found that to enhance sustainability in the curricula, academics should develop collaborative approaches, and discuss how to redesign their own disciplines, and how to appreciate the epistemology and multicultural vision of sustainability, both as a topic, and as a field of education research. It was further found that reflections of the academics on their own values are crucial for developing the transformative potential of students as agents of a sustainable future. It is necessary that universities should transform to serve as models of social justice and environmental stewardship, and to foster sustainability learning

Characterization of two poplar homologs of the GRAS/SCL gene, which encodes a transcription factor putatively associated with salt tolerance

To cope with soil salinity, which is one of the most severe forms of abiotic stress, efforts are being undertaken to enhance the salt tolerance of economically important poplar clones in the Vojvodina region of Serbia. One approach is to screen nucleotide diversity in candidate genes (CG) in several poplar clones of high economic importance to Serbia to search for associations with salt stress tolerance. As plant-specific GRAS/SCL transcription factors (TFs) play diverse roles in abiotic stress resistance, two poplar homologs of GRAS/SCL TFs were chosen to differentiate the species background with respect to salt tolerance. A BLAST search of the Populus trichocarpa genome using the P. euphratica gene GRAS/SCL TF_GH611858 sequence identified two putative orthologs, Scaf_5 and Scaf_7, with identities of 100% and 94%, respectively. Primers were designed in identical sequences of Scaf_5 and Scaf_7 to amplify fragments of GRAS/SCL TF orthologs in four poplar clones that are economically important to Serbia. The primers spanned regions where, at least in P. trichocarpa, single nucleotide polymorphisms (SNPs) are present, thereby increasing the probability of distinguishing Scaf_5 and Scaf_7 orthologs in the four clones. Alignments and analyses of the gene fragments revealed that both orthologs were representative of the genetic diversity between different poplar clones, and the identified SNP markers differentiated the four poplar clones with respect to salt tolerance

Looking for a healthy breath - the importance and potential of urban green spaces in the city: Case study of Novi Sad, Vojvodina, Province, Serbia

info:eu-repo/semantics/publishe

Plastic Growth response of European beech provenances to dry site conditions

Due to projected global warming, there is a great concern about the ability of European beech to adapt to future climate conditions. Provenance trials provide an excellent basis to assess the potential of various provenances to adjust to given climate conditions. In this study we compared the performance of four European beech (Fagus sylvatica L.) provenances growing in a provenance trial at the Fruška Gora Mountain, Serbia. Three of the investigated provenances (Höllerbach and Hasbruch from Germany and Vrani Kamen from Croatia) originate from moist sites, with annual precipitation sums being twice as high as at the provenance trial in Serbia. The performance of these provenances are compared to the growth of the local provenance Fruška Gora which is well adapted to dry site conditions. We analysed tree-ring width, mean vessel area, vessel density and water-conductive area for the period from 2006 to 2012. In spite of differences in climate conditions at their place of origin all beech provenances showed a similar pattern in radial increment. Also the wood- anatomical variables showed similar inter-annual patterns for all provenances and no significant differences between the provenances. This indicates that beech provenances from moist environments can adjust to the relatively dry temperate climate in Serbia