Springs in South-Central Poland : changes and threats

Springs are an attractive and dynamic element of natural environment, as well as an important part of cultural landscape. Numerous studies have been undertaken in the Krakowsko-Wielunska and Miechowska Uplands for over 40 years. As many as 246 springs were mapped in the 1970’s and investigations have continued to the present. These have considered the type of spring, discharges, chemical composition of water, and spring surroundings including the species composition of habitats. The long period of observations has revealed changes of spring properties due to natural and anthropogenic factors. Only 38% of investigated springs maintained their natural character. The majority were completely devastated and overwhelmed. Waste was found in more than 20 springs. Also a decrease in spring discharge of about 10-30% compared to the 1970’s and 1990’s was noticed. But there was no clear common tendency of improvement or degradation of water quality in the whole area. However the problem of spring water pollution still persists mostly due to agriculture activity and long distance air pollution transport. Interdisciplinary research and collaboration of scientists with local authorities seems to be the only way to solve the problem of spring water quality and adequate management of their surroundings. Results of the studies have provided knowledge and a basis for concrete management application

Linking soils and streams during events : response of stream water K+K^{+} concentration to soil exchangeable K+K^{+} concentration in small catchments with fragipan soils (Carpathian Foothills, Poland)

The study aimed to determine the linkage between soil exchangeable potassium ($K^{+}$) concentration and stream water $K^{+}$ concentration during rainfall and snowmelt events in small catchments with different land use (Carpathian Foothills, Poland). The complementary geochemical and hydrochemical approach used in the study produced new information on the role of particular soil horizons and contributing areas such as hillslope or riparian areas in $K^{+}$ delivery to stream channels during events. Horizons lying above the nearly impermeable fragipan (Btx) play the most important role in the process of $K^{+}$ influx to streams during most event types except snowmelts with frozen soils, in all the studied catchments. In the woodland catchment, rapid flushing of $K^{+}$ from the topsoil Ah horizon with higher hydraulic conductivity ($K_{sat}$) and higher exchangeable K+ concentrations than in the lying lower E horizon resulted in a clockwise hysteresis of $K^{+}$ in stream water during most events. In agricultural catchments, changes in stream water $K^{+}$ concentration during events were determined by distinct differences between soil exchangeable $K^{+}$ concentrations on hillslopes and in riparian areas

Crystal structure and mechanism of action of the N6-methyladenine-dependent type IIM restriction endonuclease R.DpnI.

DNA methylation-dependent restriction enzymes have many applications in genetic engineering and in the analysis of the epigenetic state of eukaryotic genomes. Nevertheless, high-resolution structures have not yet been reported, and therefore mechanisms of DNA methylation-dependent cleavage are not understood. Here, we present a biochemical analysis and high-resolution DNA co-crystal structure of the N(6)-methyladenine (m6A)-dependent restriction enzyme R.DpnI. Our data show that R.DpnI consists of an N-terminal catalytic PD-(D/E)XK domain and a C-terminal winged helix (wH) domain. Surprisingly, both domains bind DNA in a sequence- and methylation-sensitive manner. The crystal contains R.DpnI with fully methylated target DNA bound to the wH domain, but distant from the catalytic domain. Independent readout of DNA sequence and methylation by the two domains might contribute to R.DpnI specificity or could help the monomeric enzyme to cut the second strand after introducing a nick

Temperature of spring water in Polonina Wetlinska massif

The temperature of spring water reflects recharge condition, depth, and circulation time of supplying with ground water. The aim of the study was to characterize spring water temperature in Polonina Wetlinska massif and to determine the factors controlling its spatial diversity and seasonal changes. The data from field mapping in 2010 and 2011 were used along with data collected in 2012-14 by automatic data logger. Neither regularity in spatial diversity of spring water temperature was identified nor was relation with elevation and slope exposition. On the other hand a dependency between spring water temperature and type of outflow (rheocrene/bog springs) was observed, which was controlled by the heating process of groundwater in spring niche. The same mechanism controlled the higher temperature of water in springs of low discharge than observed in the most abundant ones. The temperature of monitored spring were stable throughout the year - the annual amplitude did not exceed 2^{\circ}C. Two types of thermal regime were identified