Presented here are the results of research on spatial organisation among hares originating from enclosure-type rearing but released into a natural environment for them. The fates of the 60 animals were traced by radiotelemetry in the course of four successive years of research. The mean annual home range size was found to be 1.68 km 2 in males, significantly greater than that noted for females (0.43 km 2). Similar relationships were observed in the case of seasonal ranges. The mean distance of movements noted for hares between successive radio-locations in the first month after release (at 239 m) was significantly greater than that noted for the second month (103 m) or the third (116 m). The mean distance of movement within individual annual home range for the males hares was 335 m and was significantly greater than that for females (226 m). Similar findings were obtained for seasonal ranges.
Arsenic release and its kinetic in severely contaminated stream sediments of the Kyjov brook and impoundment material (eastern Slovakia) using column and batch experiments was studied. The results of the column experiments showed that As release from the solid samples by water was likely controlled by Fe and Mn oxyhydroxides and pH of the sediments and leachates. It was also observed that extraction time was an important factor influencing the As release. The empirical correlations between the rate constants of As release and oxalate-extractable Fe content or total Mn content imply that diffusion in hydrated micropores of amorphous Fe and Mn oxides might be the rate-limiting mechanism of the As release. Although the fractions of As released in column experiments were generally less than 10 % of its total contents, these low fractions represented high absolute amounts of readily available and water-soluble As with a mean value of 83 mg kg-1. This amount of readily available As is approximately 4-times higher than the guideline value for As according to DEFRA UK, based upon ''bioavailable'' concentration, indicating high As availability for plants and living organisms in the studied region. and V štúdii bolo sledované uvoľňovanie arzénu a jeho rýchlosť vo výrazne kontaminovaných riečnych sedimentoch toku Kyjov na východnom Slovensku a materiáli odkaliska použitím kolónových a nádobkových experimentov. Výsledky kolónových experimentov naznačujú, že pravdepodobne najväčší vplyv na uvoľňovanie As vodou majú oxyhydroxidy Fe a Mn a pH výluhov a použitých sedimetov. Ukázalo sa, že aj čas trvania kontaktu kontaminovaných vzoriek s roztokom je dôležitý faktor uvoľňovania As. Nájdené korelácie medzi rýchlostnými konštantami uvoľňovania As a extrahovateľnými obsahmi Fe šťavelanom amónnym ako aj celkovými obsahmi Mn by mohli poukazovať na fakt, že difúzia v hydratovaných mikropóroch amorfných oxyhydroxidov Fe a Mn je hlavný mechanizmus limitujúci rýchlosť uvoľňovania As. Hoci frakcie uvoľneného As v kolónových experimentoch boli celkovo nižšie ako 10 % z jeho totálnych obsahov v skúmaných vzorkách, tieto nízke frakcie predstavujú vysoké obsahy ľahko dostupného a vo vode rozpustného As s priemernou hodnotou 83 mg kg-1. Uvedený obsah ľahko dostupného As je približne 4-krát vyšší ako smernicová hodnota podľa DEFRA UK založená na ''biodostupnej'' koncentrácii As. Toto porovnanie poukazuje na potenciálne vysokú dostupnosť As pre rastliny a živé organizmy v študovanej oblasti
Dental composite materials often contain monomers with bisphenol A (BPA) structure in their molecules, e.g. bisphenol-A glycidyl dimethacrylate (Bis-GMA). In this study, it was examined whether dental restorative composites could be a low-dose source of BPA or alternative bisphenols, which are known to have endocrine-disrupting effects. Bis-GMA-containing composites Charisma Classic (CC) and Filtek Ultimate Universal Restorative (FU) and “BPA-free” Charisma Diamond (CD) and Admira Fusion (AF) were examined. Specimens (diameter 6 mm, height 2 mm, n=5) were light-cured from one side for 20 s and stored at 37 °C in methanol which was periodically changed over 130 days to determine the kinetics of BPA release. BPA concentrations were measured using a dansyl chloride derivatization method with liquid chromatography - tandem mass spectrometry detection. The amounts of BPA were expressed in nanograms per gram of composite (ng/g). BPA release from Bis-GMA-containing CC and FU was significantly higher compared to “BPA-free” CD and AF. The highest 1-day release was detected with FU (15.4±0.8 ng/g), followed by CC (9.1±1.1 ng/g), AF (2.1±1.3 ng/g), and CD (1.6±0.8 ng/g), and the release gradually decreased over the examined period. Detected values were several orders of magnitude below the tolerable daily intake (4 µg/kg body weight/day). Alternative bisphenols were not detected. BPA was released even from “BPA-free” composites, although in significantly lower amounts than from Bis-GMA-containing composites. Despite incubation in methanol, detected amounts of BPA were substantially lower than current limits suggesting that dental composites should not pose a health risk if adequately polymerized., Markéta Šimková, Antonín Tichý, Michaela Dušková, Pavel Bradna., and Obsahuje bibliografii