Understanding the impacts of climate change on the future growth of tree species is particularly important for conserving endemic species with limited geographic distributions,such as Serbian spruce(Picea omorika(Panc...Understanding the impacts of climate change on the future growth of tree species is particularly important for conserving endemic species with limited geographic distributions,such as Serbian spruce(Picea omorika(Pancic)Purk.).This study describes an approach to assessing the effects of future climate conditions on the growth and the implications for future management to conserve this endangered species on the IUCN Red List.To investigate the climate-growth relationship,age structure and diameter growth trends,we have sampled 231 trees across 11 locations at National Park"Tara"in western Serbia.The existence of heterogeneous age structures suggests that Serbian spruce poses considerable potential for continual regeneration in stands with open canopy.Conducted dendroclimatological analysis exhibits exceptional coherence in growth patterns within populations(Rxy 0.67–0.78),allowing the established climate-sensitive mixed-effect model to achieve conditional R^(c)^(2)=0.683.It is revealed that the radial increment of Serbian spruce is dominantly regulated by water deficit in the summer season.The rainfall amount during the spring is another meaningful climatic factor for growth trends,while minimal winter temperatures and previous autumn water balance show varying influences.Finally,the growth projections under climate change scenarios RCP4.5 and RCP8.5 foreseen reductions of up to one-third and almost half from the historical mean growth rate.The given estimations should be seen as a critical warning signal calling for immediate conversion from passive to active protection to preserve this unique species.展开更多
AIM:To translate the Glaucoma Quality of Life-15(GQL-15)to Serbian language and asses its validity and reliability in the population of Serbian patients.METHODS:The study included 177 glaucoma patients.Clinical parame...AIM:To translate the Glaucoma Quality of Life-15(GQL-15)to Serbian language and asses its validity and reliability in the population of Serbian patients.METHODS:The study included 177 glaucoma patients.Clinical parameters(visual acuity,mean defect and square root of loss variance of visual field)and socio-demographic data were collected.Patients were stratified according to the Nelson’s glaucoma staging system as mild,moderate and advanced glaucoma.All patients filled out the GQL-15 and National Eye Institute Visual Function Questionnaire(NEI-VFQ 25).The GQL-15 was translated following the internationally-accepted methodology,and its psychometric properties were assessed by using classical test theory and Rasch analysis.RESULTS:The mean total score for the GQL-15 was 20.68±7.31.The Cronbach’s alpha coefficient for the whole scale was 0.89(central and near vision,α=0.24;peripheral vision,α=0.85;glare and dark adaptation,α=0.83).Factor analysis established 4 factors(70.3%of variance):two corresponding to the original factors and two new factors specific for the Serbian population.The GQL-15 score correlated positively with almost all clinical parameters and NEI-VFQ 25 proving good criterion validity.Correlation of the GQL-15 total score on test-retest confirmed appropriate scale reproducibility(ρ=0.96,P〈0.001).The GQL-15 discriminated well advanced from mild and moderate glaucoma.In Rasch analysis we obtained adequate item(0.95)reliability index.Almost all items had infit and outfit mean squares in the accepted range.CONCLUSION:Serbian version of the GQL-15 demonstrates adequate reliability and validity.This version of the GQL-15is a valid instrument for evaluation of quality of life among Serbian speaking patients with glaucoma and can be applied in daily clinical work.展开更多
Since Serbia disposes with significant natural potentials, it could have been among the most attractive countries in Europe only if the historical circumstances had been different. Existing natural resources and possi...Since Serbia disposes with significant natural potentials, it could have been among the most attractive countries in Europe only if the historical circumstances had been different. Existing natural resources and possibilities for their improvement demand planned strategy to make them efficient. Tourism, as a significant instrument of development, can and should take an active part in the strategy of sustainable development. Special attention in the paper is paid to the development of Vrnjacka Banja Spa as it is one of the main tourist destinations in Serbia. The strengths, weaknesses, opportunities, and threats of a business venture （SWOT） analysis offers the basic elements for defining the strategic direction and program priorities, measures and targets for improving the overall development of spas in Serbia. To identify the SWOT factors, we used materials from a number of studies on Serbian tourism, surveys on tourists in Vrnjcka Banja Spa and analysis of the market and competition. The SWOT analysis proves that the priority in development of spas in Serbia is attractiveness of the destination which involves the spa-health tourism with great potential in complementary forms of tourism, such as sport-recreational, cultural, transit and hunting tourism. It means that the future strategy should be based on improving and involving modern spa products. It means improving and maximizing marketing so as to make the tourist destination attractive. It further implies maximum investment in modern tourist products.展开更多
In the paper,the Matlab-Simulink model of simulation of operation of theŽS 413/417 series EMU(electric multiple unit)in traction and braking mode is exposed where changes are observed:stator currents of three-phase tr...In the paper,the Matlab-Simulink model of simulation of operation of theŽS 413/417 series EMU(electric multiple unit)in traction and braking mode is exposed where changes are observed:stator currents of three-phase traction motors,traction electric motor speeds and EMU,electromagnetic torque on the rotor shaft of the traction electric motor and DC(direct current)bus voltage.The model allowed review of the listed parameters for:different allowed values of contact network voltage and total voltage distortion at the place of connection of the EMU to the contact network,different mechanical loads of EMU and traction electric motor and different train speeds and rotation of traction electric motors.Appropriate conclusions were made through the analysis of the simulation results obtained.展开更多
基金supported by the perennial project activities financed by National Park“Tara”(grants no.1159&1344)The research engagement of M.K.and B.S.was supported by the Ministry of Education,Science and Technological Development of the Republic of Serbia within the framework of the program technological development(grant no.200169)+1 种基金The work of M.K.was also supported by the Science Fond of the Republic of Serbia,grant no.6686EO and in situ based information framework to support generating Carbon Credits in forestry-ForestCO2。
文摘Understanding the impacts of climate change on the future growth of tree species is particularly important for conserving endemic species with limited geographic distributions,such as Serbian spruce(Picea omorika(Pancic)Purk.).This study describes an approach to assessing the effects of future climate conditions on the growth and the implications for future management to conserve this endangered species on the IUCN Red List.To investigate the climate-growth relationship,age structure and diameter growth trends,we have sampled 231 trees across 11 locations at National Park"Tara"in western Serbia.The existence of heterogeneous age structures suggests that Serbian spruce poses considerable potential for continual regeneration in stands with open canopy.Conducted dendroclimatological analysis exhibits exceptional coherence in growth patterns within populations(Rxy 0.67–0.78),allowing the established climate-sensitive mixed-effect model to achieve conditional R^(c)^(2)=0.683.It is revealed that the radial increment of Serbian spruce is dominantly regulated by water deficit in the summer season.The rainfall amount during the spring is another meaningful climatic factor for growth trends,while minimal winter temperatures and previous autumn water balance show varying influences.Finally,the growth projections under climate change scenarios RCP4.5 and RCP8.5 foreseen reductions of up to one-third and almost half from the historical mean growth rate.The given estimations should be seen as a critical warning signal calling for immediate conversion from passive to active protection to preserve this unique species.
文摘AIM:To translate the Glaucoma Quality of Life-15(GQL-15)to Serbian language and asses its validity and reliability in the population of Serbian patients.METHODS:The study included 177 glaucoma patients.Clinical parameters(visual acuity,mean defect and square root of loss variance of visual field)and socio-demographic data were collected.Patients were stratified according to the Nelson’s glaucoma staging system as mild,moderate and advanced glaucoma.All patients filled out the GQL-15 and National Eye Institute Visual Function Questionnaire(NEI-VFQ 25).The GQL-15 was translated following the internationally-accepted methodology,and its psychometric properties were assessed by using classical test theory and Rasch analysis.RESULTS:The mean total score for the GQL-15 was 20.68±7.31.The Cronbach’s alpha coefficient for the whole scale was 0.89(central and near vision,α=0.24;peripheral vision,α=0.85;glare and dark adaptation,α=0.83).Factor analysis established 4 factors(70.3%of variance):two corresponding to the original factors and two new factors specific for the Serbian population.The GQL-15 score correlated positively with almost all clinical parameters and NEI-VFQ 25 proving good criterion validity.Correlation of the GQL-15 total score on test-retest confirmed appropriate scale reproducibility(ρ=0.96,P〈0.001).The GQL-15 discriminated well advanced from mild and moderate glaucoma.In Rasch analysis we obtained adequate item(0.95)reliability index.Almost all items had infit and outfit mean squares in the accepted range.CONCLUSION:Serbian version of the GQL-15 demonstrates adequate reliability and validity.This version of the GQL-15is a valid instrument for evaluation of quality of life among Serbian speaking patients with glaucoma and can be applied in daily clinical work.
文摘Since Serbia disposes with significant natural potentials, it could have been among the most attractive countries in Europe only if the historical circumstances had been different. Existing natural resources and possibilities for their improvement demand planned strategy to make them efficient. Tourism, as a significant instrument of development, can and should take an active part in the strategy of sustainable development. Special attention in the paper is paid to the development of Vrnjacka Banja Spa as it is one of the main tourist destinations in Serbia. The strengths, weaknesses, opportunities, and threats of a business venture （SWOT） analysis offers the basic elements for defining the strategic direction and program priorities, measures and targets for improving the overall development of spas in Serbia. To identify the SWOT factors, we used materials from a number of studies on Serbian tourism, surveys on tourists in Vrnjcka Banja Spa and analysis of the market and competition. The SWOT analysis proves that the priority in development of spas in Serbia is attractiveness of the destination which involves the spa-health tourism with great potential in complementary forms of tourism, such as sport-recreational, cultural, transit and hunting tourism. It means that the future strategy should be based on improving and involving modern spa products. It means improving and maximizing marketing so as to make the tourist destination attractive. It further implies maximum investment in modern tourist products.
文摘In the paper,the Matlab-Simulink model of simulation of operation of theŽS 413/417 series EMU(electric multiple unit)in traction and braking mode is exposed where changes are observed:stator currents of three-phase traction motors,traction electric motor speeds and EMU,electromagnetic torque on the rotor shaft of the traction electric motor and DC(direct current)bus voltage.The model allowed review of the listed parameters for:different allowed values of contact network voltage and total voltage distortion at the place of connection of the EMU to the contact network,different mechanical loads of EMU and traction electric motor and different train speeds and rotation of traction electric motors.Appropriate conclusions were made through the analysis of the simulation results obtained.
