Photosynthetic characteristics of phytoplankton in eutrophic waters

Photosynthesis and primary production were estimated in fishpond phytoplankton during period 2008-2010 in Třeboň fishpond region, Czech Republic. Photosynthesis was measured by the oxygen method in computer-assisted light pipetting system Illuminova. Altogether 64 samples of fishpond phytoplankton and 11 cyanobacterial cultures were analysed. Cyanobacteria and chlorococcal algae formed the most important part of phytoplankton biomass and their photosynthesis-irradiance (P-I) curves showed shade-adapted type of P-I curves with the high photosynthetic efficiency. No significant differences in the main parameters of P-I curves were obtained between different types of phytoplankton (chlorococcal-dominated, cyanobacteria- dominated). The results are consistent with the high turbid conditions in eutrophic or hypetrophic fishponds. On the contrary photosynthesis in cyanobacterial cultures differs from "wild" phytoplankton and therefore they can not be taken in primary production models. Primary production was estimated according Talling's model (1957), based on daily measurement of radiation, extinction coefficient of water and seasonal courses of chlorophyll concentration. Photosynthetic capacity and onset of light saturation determined in P-I curves were used as physiological parameters of Talling's model. The..

Photosynthetic activity of phytoplankton in eutrophic waters

Photosynthesis was measured in several natural populations and cultivated strains of cyanobacteria. In the natural fishpond phytoplankton species of the Microcystis genus and small {$\mu$}-cyanobakteria were dominated. Anabaena mendotae and Anabaena lemmermannii, different cultivated strains were selected for photosynthesis measurements. Photosynthesis was estimated as an oxygen evolution in Illuminova (Sweden AB) light pippeting system. During the experiment the oxygen concentration, temperature and photon flux density were detected automatically and registered in computer. Results were evaluated as Photosynthesis-Irradiance (P-I) response curves. Altogether 13 experiments were performed. In the natural cyanobacterial populations as well as in the cultivated strains the results confirmed high efficiency of photosynthesis in low irradiances. In some natural waterbloom-forming populations of Microcystis the results demonstrated also the high photosynthetic performace in high irradiances. It is evident that these cyanobacteria are able to avoid damage to the photosynthetic apparatus in photooxidative conditions. These findings probably reflect the mechanism by which cyanobacteria outcompete chlorococcal algae in the shallow eutrophic water bodies

Women´s Attitudes towards Alternative Birhting

The bachelor's research work "Women´s Attitudes towards Alternative Birhting" is focusing on the topic of alternative birthing, especially birthing outwith the medical facilities, that are currently quite often discussed issues. Alternative birthing is the matter of historical, legislagive and personal aspect. The objective of the research is to find out more about the women´s attitude towards the alternative birthing and reasons that lead to this choice, or, on the contrary, the reasons that discourage them from it. The historical development of obstetrics and birth assistance in the Czech Republic and abroad is described in the theoretical part as well as gradual transition of childbirths from homes to medical facilities, where the main objective is to secure the accessible medical care and to reduce the risk of birth in injuries for mothers and children. Appropriate attention is also paid to current situation and legislation in the Czech Republic, as the alternative birthing issues are not satisfying in this matter. Contemporary pressure of some experts as well as non-professionals on the freedom of making decisions about the births and place of births is mentioned here. The summary of opinions of supportes and opponents of this possibility is presented . Positives, negatives, complications and health hazards of deliveries, not only outwith the medical facilities, are described briefly. The post of midwifes and their qualifications embodied in legislature is also mentioned. Practical part of the dissertation is the qualitative research of the sample of four women who were asked about their attitude towards the alternative birthing issue through the designed indepth interview. These talks are processed and analysed. The result is the attitude of the presented sample of women towards this issue, which, however, does not respond to neither supporters´or opponents´ view. All the interviewed women appreciate the intimacy of alternative birthing, its course, familiar and informal atmosphere and a certain possibility of motion during the birth itself. On the other hand, they also realize possible complications related to the delivery and they are aware of the fact that if the medical help is late or not possible, there is an enhanced risk for mother and child. From the survey with this presented sample of respondents it can be concluded that all these women would welcome the posibility to deliver at the maternal hospital with the immediate medical care, in case of complications, but they would appreciate the stay with more privacy,comfort, possibility to move and certain freedom to cooperate on the procedures. Some of the women would appreciate delivery with the help of midwife who would be appointed in advance, if the physiological delivery is without problems. That means that there would be only the midwife during the delivery but the doctor would not be present

Insight into Unprecedented Diversity of Cyanopeptides in Eutrophic Ponds Using an MS/MS Networking Approach

Man-made shallow fishponds in the Czech Republic have been facing high eutrophication since the 1950s. Anthropogenic eutrophication and feeding of fish have strongly affected the physicochemical properties of water and its aquatic community composition, leading to harmful algal bloom formation. In our current study, we characterized the phytoplankton community across three eutrophic ponds to assess the phytoplankton dynamics during the vegetation season. We microscopically identified and quantified 29 cyanobacterial taxa comprising non-toxigenic and toxigenic species. Further, a detailed cyanopeptides (CNPs) profiling was performed using molecular networking analysis of liquid chromatography-tandem mass spectrometry (LC-MS/MS) data coupled with a dereplication strategy. This MS networking approach, coupled with dereplication, on the online global natural product social networking (GNPS) web platform led us to putatively identify forty CNPs: fourteen anabaenopeptins, ten microcystins, five cyanopeptolins, six microginins, two cyanobactins, a dipeptide radiosumin, a cyclooctapeptide planktocyclin, and epidolastatin 12. We applied the binary logistic regression to estimate the CNPs producers by correlating the GNPS data with the species abundance. The usage of the GNPS web platform proved a valuable approach for the rapid and simultaneous detection of a large number of peptides and rapid risk assessments for harmful blooms