There are not enough studies that describe the isokinetic strength of professional soccer players at high angular velocities. The purpose of this study was to evaluate the seasonal changes in isokinetic strength of Turkish professional soccer players (n=14) over the course of a 24-week soccer season. The isokinetic strength of players who underwent usual soccer training and weekly competition throughout the soccer season was assessed by means of the Biodex System 3 dynamometer with the knee attachment. The peak torque of knee extensor and flexor muscles were measured at angular velocities of 60°/s, 300°/s and 500°/s. Players were tested at the beginning and end of the competitive season. While the first- and second-test measurements did not show significant changes at 60°/s and 300°/s angular velocities, at the end of the training period, players' knee strength changed significantly at 500°/s angular velocities. In addition, the H/Q ratio improved significantly for the dominant as well as non-dominant leg at 500°/s. Significant bilateral strength improvements for knee flexors were also observed at 500°/s. The findings of this study suggest that usual daily soccer training (technical, tactical, power, strength, endurance, flexibility, etc.) and weekly competition might produce changes in knee strength at high angular velocities.
In the present paper we show results of our research on the contents of selected heavy metals in the surface and subsurface water layers of the estuarine lake Gardno. Obtained results show that there are substantial differences between concentrations of lead, copper and zinc in surface microlayer and subsurface waters. We observed that the surface microlayer is capable of accumulating much higher amounts of these metals than the subsurface waters. Analysis of seasonal changes in heavy metal concentrations in surface microlayers and subsurface waters shows some periodicity of these changes.
PL
W prezentowanej pracy są przedstawione wyniki analizy stężenia metali ciężkich w powierzchniowej i podpowierzchniowej warstwie wody estuariowego jeziora Gardno. Uzyskane wyniki wskazują, że są znaczące różnice między stężeniem ołowiu, miedzi i cynku w mikrowarstwie powierzchniowej wody a ich stężeniem w warstwie wody podpowierzchniowej. Zaobserwowano, że mikrowarstwa powierzchniowa ma zdolność do akumulowania znacznie wyższych ilości tych metali niż woda podpowierzchniowa. Analiza zmian sezonowych fluktuacji koncentracji metali ciężkich w mikrowarstwie powierzchniowej i podpowierzchniowej wody wskazuje na periodyczny charakter tych zmian.
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Taxonomic composition, spatial distribution and seasonal changes in abundance of ciliates were investigated in hygroarenal (the zone of the beach adjacent to lake littoral and affected by wave action) of the eutrophic Lake Mikołajskie (area 498 ha, max. depth 26 m, Masurian Lake District, Poland). The choosen beach amounted 10.8 x 1.5 m in size and 30 sampling points were distributed according to regular network 60 x 30 cm. Three sampling points were located in each of 10 sampling stations parallel to water line and at an increasing 0, 30, 60 cm distance from it). The small-scale distribution of ciliates was recognized from the set of 30 samples taken once in June 2003 from all stations and sampling points. The seasonal changes of ciliate density were analysed on the set of 41 samples taken from March to November 2004 from the middle sampling points (about 30 cm from water line) in 3 sampling stations. Ciliate community was characterised by relatively high taxonomic richness (56 ciliate taxa) and numbers (up to 2750 ind. cm[^-3] of sand). The numbers of ciliates varied seasonally from 4.6 to 1630 ind. per 1 cm[^3] of sand, showed three distinct peaks (maximum in summer) and were markedly differentiated among the sampling stations distributed along the 10 m of homogenous beach. Significant correlations between ciliates and the share of largest grain size fraction suggest that grain size of sand may be responsible for the observed spatial heterogeneity of ciliates. Hymenostomes, particularly the omnivorous Pleuronema coronatum Kent, dominated the ciliate assemblages. The statistical analysis showed a significant correlation between ciliate numbers and total phosphorus and total nitrogen concentrations in interstitial water, but there was no correlation with chlorophyll a.
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In order to investigate the effect of salinity level on the concentration of cadmium and manganese in the surface microlayer, several samples were collected from an estuarine lake Gardno in a quarterly cycle over the period of four years. Three testing stations were established in locations typical of this lake. In the estuarine lake Gardno, one can distinguish three areas with various levels of salinity, with a sampling site for each of these areas. The volume of water taken as samples varied, depending on the techniques used. During the experiment, surface microlayer samples of ca 0.1 and 0.25 mm were obtained. The subsurface water was obtained at the depth of 15 cm. The collected samples were analysed with an atomic absorption spectrometer in order to determine the concentration of cadmium and manganese. Cadmium accumulation in microlayers of surface waters in Lake Gardno was dependent on the concentration of this metal in the deep waters and varied with water salinity. In turn, counts of heterotrophic bacteria had a significant effect on the concentration of manganese. Concentrations of both metals in analyzed surface water microlayers were higher than in the subsurface layer.
PL
Badając wpływ zasolenia na koncentrację kadmu i manganu w mikrowarstwie powierzchniowej wody, próbki tej mikrowarstwy pobierano z estuariowego jeziora Gardno w cyklu kwartalnym przez okres 4 lat. Na jeziorze usytuowano trzy stanowiska badawcze w jego reprezentatywnych punktach. Jezioro Gardno jest zbiornikiem estuariowym i można w nim wyróżnić trzy zasadnicze strefy o różnym zasoleniu. W zależności od stosowanej techniki pobierania próbek wody zbierano mikrowarstwę powierzchniową wody o grubości około 0,1 mm i około 0,25 mm. Wodę podpowierzchniową pobierano na głębokości 15 cm od lustra wody. W pozyskanych próbkach wyznaczono stężenie kadmu i manganu metodami spektrometrii atomowej. Kumulacja kadmu w mikowarstwach powierzchniowej wody jeziora Gardno była zależna od stężenia tego metalu w toni wodnej i zmieniała się wraz z zasoleniem wody. Natomiast na koncentrację manganu duży wpływ miała liczebność bakterii heterotroficznych. Stężenia obydwu metali w badanych mikrowarstwach powierzchniowych wody były większe niż w warstwie podpowierzchniowej.