43 research outputs found
The first metazoa living in permanently anoxic conditions
Get PDFAbstract Background Several unicellular organisms (prokaryotes and protozoa) can live under permanently anoxic conditions. Although a few metazoans can survive temporarily in the absence of oxygen, it is believed that multi-cellular organisms cannot spend their entire life cycle without free oxygen. Deep seas include some of the most extreme ecosystems on Earth, such as the deep hypersaline anoxic basins of the Mediterranean Sea. These are permanently anoxic systems inhabited by a huge and partly unexplored microbial biodiversity. Results During the last ten years three oceanographic expeditions were conducted to search for the presence of living fauna in the sediments of the deep anoxic hypersaline L'Atalante basin (Mediterranean Sea). We report here that the sediments of the L'Atalante basin are inhabited by three species of the animal phylum Loricifera (Spinoloricus nov. sp., Rugiloricus nov. sp. and Pliciloricus nov. sp.) new to science. Using radioactive tracers, biochemical analyses, quantitative X-ray microanalysis and infrared spectroscopy, scanning and transmission electron microscopy observations on ultra-sections, we provide evidence that these organisms are metabolically active and show specific adaptations to the extreme conditions of the deep basin, such as the lack of mitochondria, and a large number of hydrogenosome-like organelles, associated with endosymbiotic prokaryotes. Conclusions This is the first evidence of a metazoan life cycle that is spent entirely in permanently anoxic sediments. Our findings allow us also to conclude that these metazoans live under anoxic conditions through an obligate anaerobic metabolism that is similar to that demonstrated so far only for unicellular eukaryotes. The discovery of these life forms opens new perspectives for the study of metazoan life in habitats lacking molecular oxygen.</p
Transformation of JHP KABA form determiners into Descriptors of the National Library of Poland
No full textThe article contains reflections on the transformation of JHP KABA determiners into Descriptors of the National Library of Poland (DBN). The author presents the results of research on comparing lexical units in JHP KABA and DBN. She draws conclusions from her own work which consists in mapping form determiners in JHP KABA with DBNs. The author chooses examples that are representative for particular groups of determiners and presents possible solutions provided that there may be more than one. The transformation of elements expressed in JHP KABA form determiners is a complex process, and not all of the determiners can be included in DBNs. In order to prevent information loss, solutions need to be used that improve the searching process without causing information chaos. After the transformation, some of the information carried by form determiners, will appear in the bibliographic record fields that are used for other categories. Consequently, not everything that was coded as form in JHP KABA will remain so after the transformation
Hydrogenosomes of chytridiomycete fungi: further evidence for a peroxisomal ancestry
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CURSES AS A UKRAINIAN CULTURAL TRADITION
Get PDFCurses constitute a significant part of cultural life of the Ukrainian people. This study aims to analyze curses as a Ukrainian cultural tradition and trace their roots. The author suggests that all curses can be divided at least in three groups: curses which are closely associated with the country’s culture, traditions, customs, history, mythology, superstitions and religion; curses that have no specific cultural root; «tricky» curses used for playful purposes. Almost all curses are context-dependent. The article argues that the major sociocultural functions of curses are pedagogical or didactic, therapeutic and regulative. It is also shown that nowadays curses continue to be used in all spheres of life.ORCID: http://orcid.org/0000-0003-2206-016
