A myxosporean producing actinospores of the tetractinomyxon type in Hydroides norvegicus Gunnerus (Serpulidae) in Denmark was identified as a member of the family Parvicapsulidae based on small-subunit ribosomal DNA (SSU rDNA) sequences. Myxosporean samples from various Danish and Norwegian marine fishes were examined with primers that detect the novel myxosporean. Sprattus sprattus (Linnaeus) and Clupea harengus Linnaeus (Teleostei, Clupeidae) were found to be infected. The sequences of this parvicapsulid from these hosts were consistently slightly different (0.8% divergence), but both these genotypes were found in H. norvegicus. Disporic trophozoites and minute spores of a novel myxosporean type were observed in the renal tubules of some of the hosts found infected through PCR. The spores appear most similar to those of species of Gadimyxa Køie, Karlsbakk et Nylund, 2007, but are much smaller. The actinospores of the tetractinomyxon type from H. norvegicus have been described previously. In GenBank, the SSU rDNA sequences of Parvicapsulidae gen. sp. show highest identity (82%) with Parvicapsula minibicornis Kent, Whitaker et Dawe, 1997 infecting salmonids (Oncorhynchus spp.) in fresh water in the western North America. A phylogenetic analysis places P. minibicornis and Parvicapsulidae gen. sp. in a sister clade to the other parvicapsulids (Parvicapsula spp. and Gadimyxa spp.).
Na podzim roku 2018 odvysílala Česká televize na ČT2 unikátní desetidílný seriál Génius: Einstein, věnovaný životu a dílu asi nejslavnějšího fyzika všech dob. Každý pátek od září do listopadu mezi 20. a 21. hodinou tak měl každý možnost chronologicky sledovat celý Einsteinův pozoruhodný osud, často dramatický v osobní, vědecké i celospolečenské rovině.1 Na jeho pozadí tvořil své objevy, z nichž mnohé byly hodny Nobelových cen a doslova změnily historii (vzpomeňme jeho podíl na vzniku kvantové teorie, formulování speciální i obecné relativity či pozemský i kosmický dosah jeho rovnice E = mc2). To vše bylo nyní bravurně zachyceno v HD kvalitě, precizní dobové výpravě, s hvězdným hereckým obsazením postav. Co více si může přát fyzik, jemuž není lhostejná historie ani obraz, jaký má jeho obor mezi ostatními lidmi! Seriálem Génius dostal možnost sdílet "to nejlepší z dějin fyziky" se svými rodinami, přáteli nefyziky, se všemi ostatními. Nám, autorům tohoto článku, však bylo řízením osudu dopřáno více. Dostali jsme šanci aktivně se podílet na tvorbě takového výjimečného díla., Between summer 2016 and spring 2017, a unique project Genius: Einstein, devoted to the fascinating and dramatic life of the most famous physicist, was filmed in Prague and other Czech locations. The authors of this article actively contributed to this film saga by becoming its "on stage" science advisors. They designed the content of almost 100 blackboards and papers with physical and mathematical formulas, texts and schemes, which appeared throughout all ten episodes of the series. The article describes how the materials were created and explains the relevant historical background of 20th-century physics. Some stories "behind the scenes" are also narrated from the author's personal perspective., and Jiří Podolský, Pavel Cejnar.
The effect of various environmental factors on net photosynthesis rates (P^) of the differentially depth distributed Mozambican seagrasses, Cymodocea serrulata (R.Br.) Aschers and Magnus (Zannich), and Thalassodendron ciliatum (Forsk.) den Hartog, was examined. At saturating irradiances the deeper water species, T. ciliatum, showed a maximum (as measured by short term O2 evolution) of 12.67 ± 3.33 mmol(02) kg-i(Chl) s ' with added 40 mM NaHCOj (0.89 mM dissolved CO2 at pH 8); the shallower species, C. serrulata, showed maximum rates of 21.67 ± 4.17 (10 mM NaHC03; 0.26 mM dissolved CO2). Saturating irradiances were similar for both species. PN estimated by the lacunal gas discharge technique was 16.00 ± 5.00 mmol(02) kg-'(Chl) s"’ for C. serrulata and 11.67 ±6.67 for T. ciliatum. Pn of both species was reduced by increased water depth, and the pattem of the effect of depth was similar.
The effects of foliar spraying of the dithiocarbamate zineb on two cultivars of tomato grown in the field in a site with high ozone concentrations were studied by means of biomass assessment, antioxidant enzyme assays, lipid peroxidation, and chlorophyll fluorescence measurements. Zineb prevented the peroxidation of membrane lipids and decreased the activity of scavenging enzymes, which suggests that plants sprayed with zineb are subjected to lower oxidative stress than controls. The beneficial effects of zineb protection is the utilization of a larger fraction of absorbed radiant energy in photosynthesis and a larger fruit yield in plants of both cultivars. and Á. Calatayud, E. Barreno.
Tento příspěvek je hrstkou poznámek a otázek, vztahujícících se k nekonečnu v matematice. Není v něm řeč o nekonečnech, jak je potkává fyzik (nekonečnost vesmíru, singularity, obecné teorie relativity, divergence v kvantové teorii polí atd.), ale o nekonečnech zaváděných v matematice. Množné číslo je na místě, matematika totiž zná nekonečen mnoho; na vkus fyzika asi až příliš mnoho. Příspěvek není matematickým textem, neusiluje o exaktní matematické formulace, je toliko pohledem uživatele matematiky., Josef Jelen., and Obsahuje seznam literatury