SOIL EROSION EVALUATION IN THE RASTOCKI POTOK WATERSHED OF MONTENEGRO USING THE EROSION POTENTIAL METHOD

Soil erosion is the most important factor of land degradation worldwide, causing significant environmental problems in the region of South East Europe also. We studied soil erosion processes in the RastockiPotok Watershed of Montenegro using the Erosion Potential Method (EPM) of Gavrilovic, which is created in Yugoslavia and is the most suitable on catchment level for the watershed management needs in this Region. The peak discharge (Qmax) is calculated on 150 m3s-1 and there is a possibility for large flood waves to appear in the studied basin. According to our analysis, the coefficient fs, (portion under forest) is 0.45; ft (grass) is 0.41 and fg (bare land) is 0.14 and the coefficient of the river basin planning, Xa, is 0.52. Real soil losses, Gyr, were calculated on 1472m3yr-1, specific 250m3km-2yr-1. The value of the Z coefficient of 0.488 indicates that the studied watershed belongs in the Destruction Category III: the erosion process is medium. This study confirmed the findings of the other Balkan researchers that the EPM method of Professor Gavrilovic is a useful tool for calculating sediment yield in the South East Europe

Age-Related Declines in Lower Limb Muscle Function are Similar in Power and Endurance Athletes of Both Sexes: A Longitudinal Study of Master Athletes

The age-related decline in muscle function, particularly muscle power, is associated with increased risk of important clinical outcomes. Physical activity is an important determinant of muscle function, and different types of physical activity e.g. power-based versus endurance-based exercise appear to have differential effects on muscle power. Cross-sectional studies suggest that participation in power-based exercise is associated with greater muscle power across adulthood but this has not been investigated longitudinally. We recruited eighty-nine male and female power and endurance master athletes (sprint and distance runners respectively, baseline age 35–90y). Using jumping mechanography, we measured lower limb muscle function during a vertical jump including at least two testing sessions longitudinally over 4.5 ± 2.4y. We examined effects of time, discipline (power/endurance) and sex in addition to two- and three-way interactions using linear mixed-effects models. Peak relative power, relative force and jump height, but not Esslingen Fitness Index (indicating peak power relative to sex and age-matched reference data) declined with time. Peak power, force, height and EFI were greater in power than endurance athletes. There were no sex, discipline or sex*discipline interactions with time for any variable, suggesting that changes were similar over time for athletes of both sexes and disciplines. Advantages in lower limb muscle function in power athletes were maintained with time, in line with previous cross-sectional studies. These results suggest that improvements in lower limb function in less active older individuals following power-based training persist with continued adherence, although this requires further investigation in interventional studies

Greater maintenance of bone mineral content in male than female athletes, and in sprinting and jumping than endurance athletes: a longitudinal study of bone strength in elite masters athletes

Summary: We investigated longitudinal changes in tibia bone strength in master power (jumping and sprinting) and endurance (distance) athletes of both sexes. Bone mass but not cross‐sectional moment of inertia was better maintained in power than endurance athletes over time, particularly in men and independent of changes in performance. Objective: Assessment of effects of sex and athletic discipline (lower limb power events e.g. sprint running and jumping versus endurance running events) on longitudinal changes in bone strength in masters athletes. Methods: We examined tibia and fibula bone properties at distal (4% distal‐proximal tibia length) and proximal (66% length) sites using peripheral quantitative computed tomography (pQCT) in seventy‐one track and field masters athletes (30 male, 41 female, age at baseline 57.0±12.2y) in a longitudinal cohort study that included at least two testing sessions over a mean period of 4.2±3.1y. Effects of time, as well as time*sex and time*discipline interactions on bone parameters and calf muscle cross‐sectional area (CSA) were examined. Results: Effects of time were sex and discipline‐dependent, even following adjustment for enrolment age, sex, and changes in muscle CSA and athletic performance. Male sex and participation in power events was associated with better maintenance of tibia bone mineral content (BMC, an indicator of bone compressive strength) at 4% and 66% sites. In contrast, there was no strong evidence of sex or discipline effects on cross‐sectional moment of inertia (CSMI, an indicator of bone bending and torsional strength – P > 0.3 for interactions). Similar sex and discipline‐specific changes were also observed in the fibula. Conclusions: Results suggest that male athletes and those participating in lower limb power‐based rather than endurance‐based disciplines have better maintenance of bone compressive but not bending and torsional strength

Soil tillage as influenced by climate change

A long-term field trial was set up in order to define the effects of autumn or spring primary tillage upon the physical characteristics and yields of spring row crops – maize and soybean. The objectives were to assess and recommend the most effective tillage method. In the first trial year, the year factor had a stronger influence on maize yields compared to the tillage factor. In the second trial year, however, the situation was quite contrasted. The tillage factor had a stronger impact on soybean yields compared to the year factor. The twoyear investigation period was only allowed to draw some preliminary conclusions. For this reason the research will be continued

Influence of drainpipe spacing on nitrate leaching and maize yield

The objectives of the study were to determine the extent of nitrate leaching and maize yields in four drainpipe spacing variants (15 m, 20 m, 25 m and 30 m). The study was carried out at an experimental reclamation field during a period of five years (growing seasons). Maize was grown as the trial crop and the same agricultural practices were applied in all drainpipe spacing variants in all trial years. Nitrogen fertilization rates varied in different trial years (from 145 kg/ha/year to 175 kg/ha/year). The results indicate that nitrate concentrations in drainage water exceeded the allowable values in a larger part of the year (four to seven months) in all drainpipe spacing variants and maximum values were from 18.15 mg.dm−3 (drainpipe spacing of 15 m in 1999/00) up to 34.71 mg.dm−3 (drainpipe spacing of 25 m in 2002/03). Quantity of nitrogen leached differed from year to year and corresponded to the total nitrogen added with fertilization and annual precipitation. Statistically significant higher maize yields were achieved in most years with the drainpipe spacing of 15 m compared to other drainpipe spacing variants

Skeletal muscle Oxidative function in vivo and ex vivo in athletes with marked hypertrophy from resistance training

Oxidative function during exercise was evaluated in 11 young athletes with marked skeletal muscle hypertrophy induced by long-term resistance training (RTA; body mass 102.6 ± 7.3 kg, mean ± SD) and 11 controls (CTRL; body mass 77.8 ± 6.0 kg). Pulmonary O2 uptake (V̇o 2) and vastus lateralis muscle fractional O2extraction (by near-infrared spectroscopy) were determined during an incremental cycle ergometer (CE) and one-leg knee-extension (KE) exercise. Mitochondrial respiration was evaluated ex vivo by high-resolution respirometry in permeabilized vastus lateralis fibers obtained by biopsy. Quadriceps femoris muscle cross-sectional area, volume (determined by magnetic resonance imaging), and strength were greater in RTA vs. CTRL (by ∼40%, ∼33%, and ∼20%, respectively). V̇o2peak during CE was higher in RTA vs. CTRL (4.05 ± 0.64 vs. 3.56 ± 0.30 l/min); no difference between groups was observed during KE. The O2 cost of CE exercise was not different between groups. When divided per muscle mass (for CE) or quadriceps muscle mass (for KE), V̇o2 peak was lower (by 15-20%) in RTA vs. CTRL. Vastus lateralis fractional O2 extraction was lower in RTA vs. CTRL at all work rates, during both CE and KE. RTA had higher ADP-stimulated mitochondrial respiration (56.7 ± 23.7 pmol O2·s-1·mg -1 ww) vs. CTRL (35.7 ± 10.2 pmol O2·s -1mg-1 ww) and a tighter coupling of oxidative phosphorylation. In RTA, the greater muscle mass and maximal force and the enhanced mitochondrial respiration seem to compensate for the hypertrophy-induced impaired peripheral O2 diffusion. The net results are an enhanced whole body oxidative function at peak exercise and unchanged efficiency and O2 cost at submaximal exercise, despite a much greater body mass. Copyright © 2013 the American Physiological Society