Academy of Sciences of the Czech Republic

About: Academy of Sciences of the Czech Republic is a government organization based out in Prague, Czechia. It is known for research contribution in the topics: Population & Catalysis. The organization has 27866 authors who have published 71021 publications receiving 1821686 citations.

Moorea producens gen. nov., sp. nov. and Moorea bouillonii comb. nov., tropical marine cyanobacteria rich in bioactive secondary metabolites.

Abstract: The filamentous cyanobacterial genus Moorea gen. nov., described here under the provisions of the International Code of Botanical Nomenclature, is a cosmopolitan pan-tropical group abundant in the marine benthos. Members of the genus Moorea are photosynthetic (containing phycocyanin, phycoerythrin, allophycocyanin and chlorophyll a), but non-diazotrophic (lack heterocysts and nitrogenase reductase genes). The cells (discoid and 25–80 µm wide) are arranged in long filaments (<10 cm in length) and often form extensive mats or blooms in shallow water. The cells are surrounded by thick polysaccharide sheaths covered by a rich diversity of heterotrophic micro-organisms. A distinctive character of this genus is its extraordinarily rich production of bioactive secondary metabolites. This is matched by genomes rich in polyketide synthase and non-ribosomal peptide synthetase biosynthetic genes which are dedicated to secondary metabolism. The encoded natural products are sometimes responsible for harmful algae blooms and, due to morphological resemblance to the genus Lyngbya , this group has often been incorrectly cited in the literature. We here describe two species of the genus Moorea: Moorea producens sp. nov. (type species of the genus) with 3LT as the nomenclature type, and Moorea bouillonii comb. nov. with PNG5-198R as the nomenclature type.

Electronic structure of fcc Th: Spin-orbit calculation with 6 p 1'2 local orbital extension

Abstract: Ab initio electronic structure calculations of actinide compounds have a weak point when the spin-orbit coupling is treated using a scalar-relativistic basis and the second variational method due to the poor description of the $6p$ states. We extend the basis set of the second variational step by including relativistic ${p}_{1/2}$ local orbitals for the description of the $6p$ states. Our results show that the additional ${p}_{1/2}$ local orbitals significantly improve the description of actinides.

Will climate mitigation ambitions lead to carbon neutrality? An analysis of the local-level plans of 327 cities in the EU

Abstract: Cities across the globe recognise their role in climate mitigation and are acting to reduce carbon emissions. Knowing whether cities set ambitious climate and energy targets is critical for determining their contribution towards the global 1.5 °C target, partly because it helps to identify areas where further action is necessary. This paper presents a comparative analysis of the mitigation targets of 327 European cities, as declared in their local climate plans. The sample encompasses over 25% of the EU population and includes cities of all sizes across all Member States, plus the UK. The study analyses whether the type of plan, city size, membership of climate networks, and its regional location are associated with different levels of mitigation ambition. Results reveal that 78% of the cities have a GHG emissions reduction target. However, with an average target of 47%, European cities are not on track to reach the Paris Agreement: they need to roughly double their ambitions and efforts. Some cities are ambitious, e.g. 25% of our sample (81) aim to reach carbon neutrality, with the earliest target date being 2020.90% of these cities are members of the Climate Alliance and 75% of the Covenant of Mayors. City size is the strongest predictor for carbon neutrality, whilst climate network(s) membership, combining adaptation and mitigation into a single strategy, and local motivation also play a role. The methods, data, results and analysis of this study can serve as a reference and baseline for tracking climate mitigation ambitions across European and global cities.

Correlation between cytotoxicity and DNA binding of polypyridyl ruthenium complexes.

Abstract: The cytotoxicity of chloropolypyridyl ruthenium complexes of structural formulas [Ru(terpy)-(bpy)Cl]Cl, cis-[Ru(bpy)2Cl2], and mer-[Ru(terpy)Cl3] (terpy = 2,2':6'2"-terpyridine, bpy = 2,2'-bipyridyl) has been studied in murine and human tumor cell lines. The results show that mer-[Ru(terpy)Cl3] exhibits a remarkably higher cytotoxicity than the other complexes. Moreover, investigations of antitumor activity in a standard tumor screen have revealed the highest efficiency for mer-[Ru(terpy)Cl3]. In a cell-free medium, the ruthenium complexes coordinate to DNA preferentially at guanine residues. The resulting adducts can terminate DNA synthesis by thermostable VentR DNA polymerase. The reactivity of the complexes to DNA, their efficiency to unwind closed, negatively supercoiled DNA, and a sequence preference of their DNA adducts (studied by means of replication mapping) do not show a correlation with biological activity. On the other hand, the cytotoxic mer-[Ru(terpy)Cl3] exhibits a significant DNA interstrand cross-linking, in contrast to the inactive complexes which exhibit no such efficacy. The results point to a potential new class of metal-based antitumor compounds acting by a mechanism involving DNA interstrand cross-linking.

Salmonellae in gulls and other free-living birds in the Czech Republic.

Abstract: Cloacal swabs, collected from 756 wild synanthropic and exoanthropic birds of 57 species in the Czech Republic, yielded 32 strains of Salmonella typhimurium [phage types (PT) 141, 104 and 41], six isolates of S. enteritidis (PT 8, 4 and 6e), and one each of S. panama and S. anatum. Except for one S. enteritidis isolate from a grey-lag goose (Anser anser) and one S. typhimurium isolate from a coot (Fulica atra), all of the other strains were derived from black-headed gulls (Larus ridibundus), of which 24.7% were found to be infected. The black-headed gull might play a role in the dispersal of pathogenic salmonellae.