Tervise enesehinnangu sotsiaal- majanduslikud erinevused Eestis: Euroopa sotsiaaluuring 2004

Eesmärgiga kirjeldada tervise enesehinnangu sotsiaal-majanduslikke erinevusi Eestis analüüsiti 35–54aastaste täiskasvanute andmeid Euroopa sotsiaaluuringus 2004. Oma tervist hindasid vastajad 5astmelisel skaalal: väga hea, hea, rahuldav, halb ja väga halb. Uuringutulemused näitasid, et umbes pooled vastanutest hindasid oma tervist vähemalt heaks ja pooled rahuldavaks või halvemaks. Meeste ja naiste tervise enesehinnangus olulist erinevust ei leitud. Oma tervist rahuldavaks või halvemaks hinnanuid esines rohkem madalama haridustasemega, mittetöötavate, majanduslikult halvasti toime tulevate ja vanema vanuserühma meeste ning naiste hulgas. Ei leitud tervise enesehinnangu seost rahvuse, elukoha ega perekonnaseisuga. Eesti Arst 2008; 87(1):13−1

The life history of the toxic marine dinoflagellate Protoceratium reticulatum (Gonyaulacales) in culture

Asexual and sexual life cycle events were studied in cultures of the toxic marine dinoflagellate Protoceratium reticulatum. Asexual division by desmoschisis was characterized morphologically and changes in DNA content were analyzed by flow cytometry. The results indicated that haploid cells with a C DNA content occurred only during the light period whereas a shift from a C to a 2C DNA content (indicative of S phase) took place only during darkness. The sexual life cycle was documented by examining the mating type as well as the morphology of the sexual stages and nuclei. Gamete fusion resulted in a planozygote with two longitudinal flagella, but longitudinally biflagellated cells arising from planozygote division were also observed, so one of the daughter cells retained two longitudinal flagella while the other daughter cell lacked them. Presumed planozygotes (identified by their longitudinally biflagellated form) followed two life-cycle routes: division and encystment (resting cyst formation). Both the division of longitudinally biflagellated cells and resting cyst formation are morphologically described herein. Resting cyst formation through sexual reproduction was observed in 6.1% of crosses and followed a complex heterothallic pattern. Clonal strains underwent sexuality (homothallism for planozygote formation and division) but without the production of resting cysts. Ornamental processes of resting cysts formed from the cyst wall under an outer balloon-shaped membrane and were fully developed in <1 h. Obligatory dormancy period was of ∼4 months. Excystment resulted in a large, rounded, pigmented, longitudinally biflagellated but motionless, thecate germling that divided by desmoschisis. Like the planozygote, the first division of the germling yielded one longitudinally biflagellated daughter cell and another without longitudinal flagella. The longitudinal biflagellation state of both sexual stages and of the first division products of these cells is discussed.Postprin

Plankton biodiversity and species co-occurrence based on environmental DNA – a multiple marker study

Metabarcoding in combination with high-throughput sequencing (HTS) allows simultaneous detection of multiple taxa by targeting single or several taxonomically informative gene regions from environmental DNA samples. In this study, a multiple-marker HTS approach was applied to investigate the plankton diversity and seasonal succession in the Baltic Sea from winter to autumn. Four different markers targeting the 16S, 18S, and 28S ribosomal RNA genes were employed, including a marker for more efficient dinoflagellate detection. Typical seasonal changes were observed in phyto- and bacterioplankton communities. In phytoplankton, the appearance patterns of selected common, dominant, or harmful species followed the patterns also confirmed based on 20 years of phytoplankton monitoring data. In the case of zooplankton, both macro- and microzooplankton species were detected. However, no seasonal patterns were detected in their appearance. In total, 15 and 2 new zoo- and phytoplankton species were detected from the Baltic Sea. HTS approach was especially useful for detecting microzooplankton species as well as for investigating the co-occurrence and potential interactions of different taxa. The results of this study further exemplify the efficiency of metabarcoding for biodiversity monitoring and the advantage of employing multiple markers through the detection of species not identifiable based on a single marker survey and/or by traditional morphology-based methods

Comparing PCR-generated artifacts of different polymerases for improved accuracy of DNA metabarcoding

Accuracy of PCR amplification is vital for obtaining reliable amplicon-sequencing results by metabarcoding. Here, we performed a comparative analysis of error profiles in the PCR products by 14 different PCR kits using a mock eukaryotic community DNA sample mimicking metabarcoding analysis. To prepare a mock eukaryotic community from the marine environment, equal amounts of plasmid DNA from 40 microalgal species were mixed and used for amplicon-sequencing by a high-throughput sequencing approach. To compare the differences in PCR kits used for this experiment, we focused on the following seven parameters: 1) Quality, 2) Chimera, 3) Blast top hit accuracy, 4) Deletion, 5) Insertion, 6) Base substitution and 7) Amplification bias amongst species. The results showed statistically significant differences (p < 0.05) for all of the seven parameters depending on the PCR kits used. These differences may result from the different DNA polymerases included in each kit, although the result can also be influenced by PCR reaction conditions. Simultaneous analysis of several parameters suggested that kits containing KOD plus Neo (TOYOBO) and HotStart Taq DNA polymerase (BiONEER, CA, US) at the annealing temperature of 65 °C displayed better results in terms of parameters associated with chimeras, top hit similarity and deletions