Relationship between the type of atrial fibrillation and thromboembolic events

Background/Aim. Atrial fibrillation (AF) increases the risk for ischemic stroke and other thromboembolic (TE) events. Aim of the study was to examine the relationship between clinical types of atrial fibrillation (AF) and (TE) events. Methods. This longitudinal, observational study included patients with nonvalvular AF as main indication for in-hospital and/or outpatient treatment in the Cardiology Clinic, Clinical Center of Serbia during a period 1992-2007. The treatment of AF was based on the International Guidelines for diagnosis and treatment of AF, correspondent to given study period. Clinical types of AF were defined according to the latest ACC/AHA/ESC Guidelines for AF, from 2006. Diagnosis of central and systemic TE events during a follow-up was made exclusively by the neurologist and vascular surgeon. Results. During a follow-up of 9.9 ± 6 years, TE events were documented in 88/1 100 patients (8%). In the time of TE event 46/88 patients (52.3%) had permanent AF. The patients with permanent AF were at baseline significantly older and more frequently had underlying heart disease and diabetes mellitus. Cumulative TE risk during follow-up was similar for patients with paroxysmal and permanent AF, and significantly higher as compared to TE risk in patients with persistent AF. However, multivariate Cox proportional hazard regression analysis with independent variables clinical types of AF at baseline and in the time of TE event, clinical and echocardiographic characteristics and therapy for prevention of TE complications at baseline and at the time of TE event, did not reveal independent predictive value of clinical type of AF for the occurrence of TE events during a follow-up. Conclusion. TE risk in patients with AF does not depend on clinical type of AF. Treatment for prevention of TE events should be based on the presence of well recognized risk factors, and not on the clinical type of AF

Ecological and Economic Effects of Applying the Future Agricultural Production Structure Model (FAPSMS): The Case Study of the Barička River Basin Sustainability

It is necessary to harmonize the needs of society in terms of agricultural production and land protection from various forms of degradation throughout sustainable land management. Assessing the justification of investment in sustainable management of land resources is an important step in this process. Consequently, an analysis of soil erosion risk was carried out in the suburban area of the morphological unit of the Barička river watershed, using the Revised Universal Soil Loss Equation (RUSLE) method, with the existing and projected structure of agricultural production according to the Future Agricultural Production Structure Model from the Aspect of Preserving Land Resources for Mountain Catchment Areas of Serbia (FAPSMS). The value of the existing and projected production structure from an economic aspect was also examined using dynamic economic methods. In order to assess the risk and uncertainty of investments, a sensitive analysis of dynamic methods was carried out. The results show that soil erosion losses are already below tolerance values with the existing production structure and that they could be reduced even more by applying the designed structure. Economic indicators show that the investment is justified and that it is more sensitive to changes in income

Ecological and economic effects of applying the Future Agricultural Production Structure Model (FAPSMS): The case of Barička river basin

It is necessary to harmonize the needs of society in terms of agricultural production and land protection from various forms of degradation. Assessing the justifi cation of investment in sustainable management of land resources is an important step in that process. Consequently, in the suburban area of the morphological unit of the Barička river basin, an analysis of soil erosion risk was carried out using the Revised Universal Soil Loss Equation (RUSLE) method, with the existing and projected structure of agricultural production according to the Future Agricultural Production Structure Model from the Aspect of Preserving Land Resources for Mountain Catchment Areas of Serbia (FAPSMS). The value of the existing and projected production structure from the economic aspect was also examined, using dynamic economic methods. In order to assess the risk and uncertainty of investments, a sensitive analysis of dynamic methods was carried out. The results of the research showed that soil erosion losses are already below tolerance values with the existing production structure and that they could be reduced even more by applying the designed structure. Economic indicators have shown that the investment is justified and that it is more sensitive to changes in income

Model for the selection of the optimal location of a thermal power unit according to the external coal conveyance criterion

Aggravated working conditions in Serbian underground coal mines, and increasingly worse natural conditions (increased depthsof deposits, expressed tectonics, large inflows of underground waters etc.) resulted in higher exploitation costs which areat the threshold of profitability. This inevitably leads to the conclusion that it is necessary to link mines to thermal power plantsand facilities. The Soko and Lubnica mines can operate cost-effectively if they ground their production on the needs of a thermal powerheatingplant (TETO) which would supply the towns of Bor and Zaječar with the power. This paper deals with finding an optimallocation of a TETO using model for the optimal external coal conveyance from a mine to a thermal power unit

Researching the possibilities of using low-temperature heat sources for sustainable energy development of cities

Одрживост је континуиран процес балансирања између животне средине, економске и социјалне димензије, који се односи на системска побољшања животног окружења. Енергија се налази међу покретачима одрживог развоја везано за потребу за повећање социјалног благостања, његову кључну улогу у економском развоју и утицај на животну средину. Урбане зоне, као центри потреба за енергијом и емисија угљеника, пружају значајне могућности за промоцију одрживости енергетског система заједнице. Планирање нових енергетских капацитета, у складу са принципима одрживог развоја, обухвата спровођење политике повећања енергетске ефикасности и увођења обновљивих извора енергије. Дисертација ставља акценат на коришћење потенцијала дела обновљивих извора, односно нискотемпературних извора топлоте, тј. на првом месту геотермалне енергије подземних вода, стена, земље, затим ваздуха, воде и Сунца за добијање топлотне енергије. Ови извори обезбеђују нижу температуру него што се добија сагоревањем фосилних горива. Међутим, њиховом употребом могу се добити значајне количине енергије и у многим системима задовољити и комплетне потребе за топлотном енергијом. При томе, коришћењем нискотемпературних извора смањује се потрошња других облика енергије, трошкови горива, уз значајно смањен негативан утицај на животну средину...Balancing of environmental, economic and social issues is the essence of sustainability. That is continuous process, related to our living environment and their systematic improvements. For sustainable development, energy is one of the most important drivers. Improving the social welfare, economic development, but also environmental impacts are closely related to energy development. Urban areas are the centers of energy demand and carbon emissions. For that reason, cities are the places where the actions for promoting the sustainability of energy systems should be initiated. Planning new facilities, in accordance with the principles of sustainable development, involves a wide range of energy efficiency measures and the introduction of renewable energy sources. The thesis emphasizes the use of renewable resources, primarily low-temperature heat sources, i.e. first geothermal ground water, rocks, soil, air, water and sun to generate heat. These sources provide a lower temperature than is obtained by burning fossil fuels. However, their use can provide significant amounts of energy and satisfy the complete heat demands in many systems. In addition, using low temperature sources reduces the consumption of other forms of energy, fuel costs, and significantly reduced the negative impact on the environment..

Researching the possibilities of using low-temperature heat sources for sustainable energy development of cities

Одрживост је континуиран процес балансирања између животне средине, економске и социјалне димензије, који се односи на системска побољшања животног окружења. Енергија се налази међу покретачима одрживог развоја везано за потребу за повећање социјалног благостања, његову кључну улогу у економском развоју и утицај на животну средину. Урбане зоне, као центри потреба за енергијом и емисија угљеника, пружају значајне могућности за промоцију одрживости енергетског система заједнице. Планирање нових енергетских капацитета, у складу са принципима одрживог развоја, обухвата спровођење политике повећања енергетске ефикасности и увођења обновљивих извора енергије. Дисертација ставља акценат на коришћење потенцијала дела обновљивих извора, односно нискотемпературних извора топлоте, тј. на првом месту геотермалне енергије подземних вода, стена, земље, затим ваздуха, воде и Сунца за добијање топлотне енергије. Ови извори обезбеђују нижу температуру него што се добија сагоревањем фосилних горива. Међутим, њиховом употребом могу се добити значајне количине енергије и у многим системима задовољити и комплетне потребе за топлотном енергијом. При томе, коришћењем нискотемпературних извора смањује се потрошња других облика енергије, трошкови горива, уз значајно смањен негативан утицај на животну средину...Balancing of environmental, economic and social issues is the essence of sustainability. That is continuous process, related to our living environment and their systematic improvements. For sustainable development, energy is one of the most important drivers. Improving the social welfare, economic development, but also environmental impacts are closely related to energy development. Urban areas are the centers of energy demand and carbon emissions. For that reason, cities are the places where the actions for promoting the sustainability of energy systems should be initiated. Planning new facilities, in accordance with the principles of sustainable development, involves a wide range of energy efficiency measures and the introduction of renewable energy sources. The thesis emphasizes the use of renewable resources, primarily low-temperature heat sources, i.e. first geothermal ground water, rocks, soil, air, water and sun to generate heat. These sources provide a lower temperature than is obtained by burning fossil fuels. However, their use can provide significant amounts of energy and satisfy the complete heat demands in many systems. In addition, using low temperature sources reduces the consumption of other forms of energy, fuel costs, and significantly reduced the negative impact on the environment..

The occurrence of new arrhythmias after catheter-ablation of accessory pathway: Delayed arrhythmic side-effect of curative radiofrequency lesion?

Introduction. New arrhythmias (NA) may appear late after accessory pathway (AP) ablation, but their relation to curative radiofrequency (RF) lesion is unknown. Objective. The aim of this study was to determine the prevalence and predictors for NA occurrence after AP ablation and to investigate pro-arrhythmic effect of RF. Methods. Total of 124 patients (88 males, mean age 43±14 years) with Wolff-Parkinson-White syndrome and single AP have been followed after successful RF ablation. Post-ablation finding of arrhythmia, not recorded before the procedure, was considered a NA. The origin of NA was assessed by analysis of P-wave and/or QRS-complex morphology, and, thereafter, it was compared with locations of previously ablated APs. Results. Over the follow-up of 4.3±3.9 years, NA was registered in 20 patients (16%). The prevalence of specific NAs was as follows: atrioventricular (AV) block 0.8%, atrial premature beats 1.6%, atrial fibrillation 5.4%, atrial flutter 0.8%, sinus tachycardia 4.8%, ventricular premature beats (VPBs) 7.3%. Multivariate Cox-regression analysis identified (1) pre-ablation history of pathway-mediated tachyarrhythmias >10 years (HR=3.54, p=0.016) and (2) septal AP location (HR=4.25, p=0.003), as the independent predictors for NA occurrence. In four NA cases (two cases of septal VPBs, one of typical AFL and one of AV-block) presumed NA origin was identified in the vicinity of previous ablation target. Conclusion. NAs were found in 16% of patients after AP elimination. In few of these cases, late on-site arrhythmic effect of initially curative RF lesion might be possible. While earlier intervention could prevent NA occurrence, closer follow-up is advised after ablation of septal AP

Parameters of anaerobic physiological profile of elite athletes

Introduction. Anaerobic capacity is much less evaluated in literature compared to aerobic component. Anaerobic performance of athletes can be measured using different motoric tests, lasting 20 to 30 seconds, one of them being the Wingate anaerobic test (WAnT). Objective. The aim of this study was to determine the work performed and power generated by athletes and non-athletes during a 30-second high intensity exercise, as well as to compare explosive characteristics of subjects using a new parameter of WAnT, named explosive power, or slope of power. Methods. All parameters of anaerobic power were investigated in 152 subjects classed into different groups depending on their physical fitness and sport specialties as follows: non-athletes (n=31), rowers (n=26), volleyball players (n=37), handball players (n=34) and judo players (n=24). The WAnT, as well as basic anthropometric measurements, was administrated to all participants. Results. Values of anaerobic parameters were higher in the group of athletes compared to physically inactive subjects. The highest values of the WAnT parameters were registered in the group of volleyball players (AP=1006 W; relative AP=11.4 W/ kg, AC=19.8 kJ), compared to athletes of other sport disciplines (volleyball, rowing and judo). The new parameter of the WAnT, explosive power, also showed highest values in volleyball players (EP=154 W/s; relative EP=1.74 W/s/kg). These differences were statistically significant (p<0.05). Conclusion. The results of laboratory tests can provide useful information on improvements in training processes. The new parameter of the WAnT could be implemented in further analyses of explosive characteristics of muscle contraction

Comparative analysis of two different methods of anaerobic capacity assessment in sedentary young men

Background/Aim. The Wingate anaerobic test is a valid and reliable method of measuring anaerobic capacity. The aim of this study was to determine whether other modified test can be used instead of the Wingate test. Methods. A group of 30 sedentary young men were first tested with a cycle ergometer (classic Wingate test), and then with a dynamometer during 30 s of 'all out' leg extension exercise (modified Wingate test; WAnTe) in order to test anaerobic capacity. Subsequent correlations between these tests were made. Results. Peak power, mean power on cycling ergometer in absolute and relative values were 463 ± 105 W, 316.7 ± 63.8 W, 5.68 ± 1.17 W/kg, 3.68 ± 0.78 W/kg, respectively. On a dynamometer absolute and relative values of maximal and mean load in kg and power in Watts were 136.54 ± 21.3 kg, 1.67 ± 0.26; 128.65 ± 19.93 kg, 1.57 ± 0.24 kg, 657 ± 125.87 W, and 8 ± 1.54 W/kg, respectively. There was no correlation between 5 s intervals of the classic Wingate test and WAnTe during the first, fourth and fifth intervals, but in the second (r = 0.49, p &lt; 0.05), third (r = 0.38, p &lt; 0.05) and last 5 s intervals (r = 0.39, p &lt; 0.05), and also in peak power and mean power (r = 0.42, p &lt; 0.05 and r = 0.45, p &lt; 0.05 respectively), a significant positive correlation was detected. Conclusion. A modified Wingate test of leg extension on a dynamometer in sedentary young men shows a correlation with the classic Wingate test only in parameters of peak power, and mean power and the second, the third and the last 5 s intervals. Because of that it should only be used for orientation, whereas for precise measurements of anaerobic capacity the classic Wingate test should be used