Adaptive mechanisms of mitochondria in response to exercise

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ASCORBIC ACID MODULATES SPONTANEOUS THYMOCYTE APOPTOSIS

The aim of the paper was to analyze the effect of various concentrations of ascorbic acid on spontaneous apoptosis of lymphocytes.About 58% of all thymocytes are subjected to a spontaneous apoptosis, after 24-hour cultivation in the complete medium. The number of apoptotic thymocytes was much lower in the culture with different concentrations of ascorbic acid. The most dramatic effect was detected in the culture with the highest concentration of ascorbic acid (10000 μg/ml). In this culture, the number of apoptotic thymocytes was about 32%. These results, compared with the results of spontaneous apoptosis, show that the most significant inhibition of apoptosis was detected in the culture with 10000 μg/ml of ascorbic acid. High concentration of ascorbic acid can inhibit spontaneous apoptosis of thymocytes. Such inhibition of T cell apoptosis, as the effector cells in immune system, can represent one of the major factors by which ascorbic acid influence the immune system

Aerobic Capacity as An Indicator in Different Kinds of Sports

Physical capacity of athletes is an important element of success in sports achievements. Aerobic capacity has been accepted as its major component. Maximal oxygen uptake (VO2max) has been regarded by majority of authors as the best indicator of aerobic capacity of an organism, and at the same time, the best indicator of an athlete’s physical capacity. The aim of the investigation was to analyze the aerobic capacity as an indicator of physical capacity of athletes, differences in their aerobic capacity with regard to the kind of sport they are practicing, as well as the differences obtained when compared to physically inactive subjects. The investigation included the determination of absolute and relative VO2max in the total of 66 male examinees. The examinees were divided into two groups of active athletes (football players (n=22) and volleyball players (n=18) of different profiles, while the third group of non-athletes served as control group. Maximal oxygen uptake was determined by performing the Astrand 6 minute cycle test. Peak values of VO2 max were recorded in the group of football players (4,25±0,27 l/min), and they were statistically significantly higher (p<0,001) compared to other examined groups. In the group of volleyball players the oxygen uptake was 3,95±0,18 l/min, while statistically significantly lower values were reported in the group of non-athletes compared to the groups of athletes (p<0,01). A similar ratio of VO2 max values was also shown by the analysis of values expressed in relative units. Our results showed that peak values of VO2 max were obtained in football players, and that football as a sport requires higher degree of endurance compared to volleyball. Having considered the morphological and functional changes which are the consequence of the training process, it can be concluded that VO2 max values are statistically significantly higher in the groups of athletes compared to the group of non-athletes

Mehanizmi financiranja sustava upravljanja zaštićenim područjima u Srbiji

The financing of protected area (PA) management includes the interaction of different actors that are involved in the process of management and financing, i.e., from the management framework to the mechanisms of financing. The management framework sets the basic preconditions for PA management, while the mechanisms of financing represent the ways of financing PAs based on the long-term and sustainable conditions. The management of PAs in Serbia has mostly been done by public enterprises (PE). It was given to non-governmental organizations (NGO) for the first time in the late 1990s. Today, the management is carried out by different managers from the public sector (PS) to the private sector (PrS). This research deals with different financing mechanisms present in PAs in Serbia. Additionally, it deals with the differences in the financing between different management actors (MA) in order to establish the best financing practices in the PA management system in Serbia. The results indicate that public enterprise “Srbijašume” (PES) has the lowest average number of financial sources, unlike public enterprise “Vojvodinašume” (PEV). Regarding the average amount of financing, other managers from the public sector (OPS) have the largest amount of financing, while other public enterprises (OPE) record the smallest amount of their own financing. In order to improve the use of mechanisms for the PA management system financing, additional training for the use of funds is proposed at national and international level, as well as external, i.e., additional engagement of agencies that would prepare projects at international level. It is also proposed to establish a specific mechanism – a fund intended for nature protection.Financiranje upravljanja zaštićenim područjima (ZP) uključuje interakciju različitih dionika koji su uključeni u proces upravljanja i financiranja, tj. od okvira upravljanja do mehanizama financiranja. Upravljački okvir postavlja osnovne preduvjete za upravljanje ZP, dok mehanizmi financiranja predstavljaju načine financiranja ZP na temelju dugoročnih i održivih uvjeta. Upravljanje ZP može se delegirati organizaciji, pojedincu ili zajednici, koja funkcionira u skladu s nizom zakona, pravila i / ili tradicijom. Isto tako, upravitelji ZP mogu se podijeliti na temelju toga tko donosi odluke i može se smatrati odgovornim. Jedna od važnih komponenti upravljanja ZP predstavlja održivo financiranje, što predstavlja temelj za ostvarivanje zaštite prirode. Održivo financiranje definira se kao sposobnost pružanja dovoljnih, stabilnih i dugoročnih financijskih izvora. Upravljanje ZP u Srbiji uglavnom provode javna poduzeća, dok je krajem devedesetih godina u Srbiji upravljanje ZP po prvi put dodijeljeno nevladinim organizacijama. Danas upravljanje provode različiti upravitelji iz javnog sektora i privatnog sektora. Planirano povećanje ZP u Srbiji uključuje skoro dvostruko veću površinu od sadašnje pokrivenosti i ta će činjenica stvoriti dodatnu obavezu za postojeće i nove upravitelje u budućem razdoblju, jer je održivo upravljanje ZP postalo izazov, kako sa upravljačkog, tako i sa financijskog gledišta. Ovo istraživanje bavi se različitim mehanizmima financiranja koji su prisutni u ZP u Srbiji. Također, bavi se razlikama u financiranju između različitih grupa upravitelja, kako bi se uspostavile najbolje prakse financiranja u sustavu upravljanja ZP u Srbiji. U fazi prikupljanja podataka korištena je anketa od vrata do vrata. Istraživanje se provodilo u dvije faze. U prvoj fazi, populacija za istraživanje definirana je na temelju registra ZP, od čega su izdvojena 63 ZP. U drugoj fazi, uzorak za istraživanje definiran je na temelju primjera „dobre prakse“ upravitelja ZP i predstavnika javne uprave i službi, kao i organizacija u sustavu upravljanja ZP. Za obradu podataka korištena je deskriptivna statistika, frekvencijska analiza, Kruskal-Wallis-ov test i Mann-Whitney-jev U test. Kruskal-Wallis-ov test korišten je za određivanje razlika između svih grupa upravitelja, dok je Mann-Whitney-jev U test korišten za određivanje razlika između pojedinih grupa upravitelja. Rezultati pokazuju da javno poduzeće “Srbijašume” ima najmanji prosječan broj izvora financiranja, za razliku od javnog poduzeća “Vojvodinašume” (tablica 1). Što se tiče prosječnih iznosa financiranja, najveći dio financiranja imaju ostali upravitelji iz javnog sektora, dok ostala javna poduzeća bilježe najmanji iznos vlastitog financiranja (tablica 2). Na temelju rezultata prve faze istraživanja predloženi su elementi unaprjeđenja sustava upravljanja ZP za mehanizme financiranja (tablica 3). Predstavnici upravitelja ZP, javne uprave i službi, kao i organizacija, smatraju da politička volja donositelja odluka, kao i nepostojanje razumijevanja države za potrebe financiranja ZP, ima velik utjecaj na unaprjeđenje postojećih mehanizama financiranja. Također, predstavnici sve tri skupine vjeruju da lokalne vlasti nisu ni uključene u financiranje ZP-a i da postoji nedovoljna zainteresiranost drugih institucija. Kao problem u unaprjeđenju korištenja domaćih i međunarodnih izvora financiranja, predstavnici upravitelja ZP vide potrebu za dodatnim istraživanjima i problemom nedovoljne izobrazbe upravitelja, za podnošenje projektnih ideja, koje su vezane uz nedovoljnu informatičku pismenost

Direct and Joint Effects of Genotype, Defoliation and Crop Density on the Yield of Three Inbred Maize Lines

The aim of this study was to observe direct and joint effects of three factors (genotypes, ecological environmental conditions and the applied crop density) on the level of defoliation intensity and yield. Three inbred lines (G) of maize (G1–L217RfC, G2–L335/99 and G3–L76B004) were used in the study. The trials were performed in two years (Y) (Y1 = 2016 and Y2 = 2017) and in two locations (L) (L1 and L2) under four ecological conditions of the year–location interaction (E1–E4) and in two densities (D1 and D2) (50,000 and 65,000 plants ha−1 ). Prior to tasselling, the following five treatments of detasseling and defoliation (T) were applied: T1—control, no leaf removal only detasseling, T2–T5—removal of tassels and top leaves (from one to four top leaves). The defoliation treatments had the most pronounced effect on the yield reduction in G1 (T1–Tn+1 . . . T5), p < 0.05. The ecological conditions on yield variability were expressed under poor weather conditions (E3 and E4), while lower densities were less favorable for the application of defoliation treatments. The result of joint effects of factors was the lowest grain yield (896 kg/ha) in G3 in the variant E3D1 for T2 and the highest grain yield (11,389 kg/ha) in G3 in the variant E2D2 for T1. The smallest effect of the defoliation treatment was on the kernel row number (KRN

Direct and Joint Effects of Genotype, Defoliation and Crop Density on the Yield of Three Inbred Maize Lines

The aim of this study was to observe direct and joint effects of three factors (genotypes, ecological environmental conditions and the applied crop density) on the level of defoliation intensity and yield. Three inbred lines (G) of maize (G1-L217RfC, G2-L335/99 and G3-L76B004) were used in the study. The trials were performed in two years (Y) (Y1 = 2016 and Y2 = 2017) and in two locations (L) (L1 and L2) under four ecological conditions of the year-location interaction (E1-E4) and in two densities (D1 and D2) (50,000 and 65,000 plants ha−1). Prior to tasselling, the following five treatments of detasseling and defoliation (T) were applied: T1-control, no leaf removal only detasseling, T2-T5-removal of tassels and top leaves (from one to four top leaves). The defoliation treatments had the most pronounced effect on the yield reduction in G1 (T1-Tn+1… T5), p < 0.05. The ecological conditions on yield variability were expressed under poor weather conditions (E3 and E4), while lower densities were less favorable for the application of defoliation treatments. The result of joint effects of factors was the lowest grain yield (896 kg/ha) in G3 in the variant E3D1 for T2 and the highest grain yield (11,389 kg/ha) in G3 in the variant E2D2 for T1. The smallest effect of the defoliation treatment was on the kernel row number (KRN)

Walnut Consumption Induces Tissue-Specific Omega-6/Omega-3 Decrease in High-Fructose-Fed Wistar Rats

Increased dietary, blood, and tissue n-6/n-3 fatty acid ratios are associated with obesity and metabolic syndrome. Due to Westernized dietary patterns, the increasing n-6/n-3 ratio is of growing concern worldwide, and dietary strategies aimed at its lowering are of public health importance. Walnuts are rich in dietary fats, and their consumption promotes cardiometabolic health. This study aimed to examine the effect of 6-week walnut consumption on tissue-specific n-6/n-3 ratio and fatty acid metabolic conversion in fructose-fed rats with a cluster of metabolic disorders. Male Wistar rats were fed a standard diet with or without 10% fructose in drinking water for 9 weeks. Diets of half of the animals were then supplemented with walnuts (2.4 g/day) for 6 weeks, upon which fatty acid profiles were determined in plasma, liver, adipose tissue, and kidney total lipids. Results showed that walnuts induced significant decreases in the n-6/n-3 content of total lipid pool in plasma and examined tissues, irrespective of metabolic burden. Walnut intervention decreased plasma and liver palmitoleic/palmitic, arachidonic/linoleic, and docosahexaenoic/alpha-linolenic acid ratios. It also modulated individual fatty acid levels by reducing arachidonic and palmitic acid and increasing alpha-linolenic, eicosapentaenoic, and docosapentaenoic acid in plasma and most tissues. Our study demonstrated that 6-week consumption of walnuts favorably modulated n-6/n-3 plasma and tissue ratio in male Wistar rats regardless of high-fructose feeding, underscoring the promising potential of walnuts in both prevention and treatment of the metabolic syndrome

OXIDATIVE STRESS, STRESS PROTEINSAND ANTIOXIDANTS IN EXERCISE

Exercise appears to increase reactive oxygen species (ROS), which can result in damage to cells. Potential sources of ROS in skeletal muscle fibers during exercise include the mitochondrial respiratory chain, xantine oxidase production of superoxide, enzymatic arachidonic acid oxygenation, nitric oxide synthesis, catecholamine oxidation, and neutrophil-induced oxidative burts. Stress proteins (SPs) represent one of the general molecular protective mechanisms that enable cell and whole organisms to survive stress. The exact relationship between exercise, ROS and SPs remains unclear. Antioxidant supplements have been touted by manufacturers as a means for athletes to perform better, recover more quickly and fully from endurance exercise, or allow them to train more strenuously. At present, data are insufficient to recommend antioxidant supplements for athletes or other persons who exercise regularly. However, no one questions the importance of ingesting a diet rich in antioxidants for all who exercise and train regularly

Physiological aspects of altitude training and the use of altitude simulators

Altitude training in various forms is widely practiced by athletes and coaches in an attempt to improve sea level endurance. Training at high altitude may improve performance at sea level through altitude acclimatization, which improves oxygen transport and/or utilization, or through hypoxia, which intensifies the training stimulus. This basic physiological aspect allows three training modalities: live high and train high (classic high-altitude training), live low and train high (training through hypoxia), and live high and train low (the new trend). In an effort to reduce the financial and logistical challenges of traveling to high-altitude training sites, scientists and manufactures have developed artificial high-altitude environments, which simulate the hypoxic conditions of moderate altitude (2000-3000 meters). Endurance athletes from many sports have recently started using nitrogen environments, or hypoxic rooms and tents as part of their altitude training programmes. The results of controlled studies on these modalities of high-altitude training, their practical approach, and ethics are summarized