The giants that were born swiftly -- Implications of the top-heavy stellar initial mass function on the birth conditions of globular clusters

Recent results suggest that the initial mass function (IMF) of globular clusters (GCs) is metallicity and density dependent. Here it is studied how this variation affects the initial masses and the numbers of core collapse supernovae (CCSNe) required to reproduce the observed iron spreads in GCs. The IMFs of all of the investigated GCs were top-heavy implying larger initial masses compared to previous results computed assuming an invariant canonical IMF. This leads to more CCSNe being required to explain the observed iron abundance spreads. The results imply that the more massive GCs formed at smaller Galactocentric radii, possibly suggesting in-situ formation of the population II halo. The time until star formation (SF) ended within a proto-GC is computed to be 3.5 - 4 Myr, being slightly shorter than the 4 Myr obtained using the canonical IMF. Therefore, the impact of the IMF on the time for which SF lasts is small.Comment: published in MNRAS, 13 pages, 12 figure

Stanovení zásad funkční obnovy městských a historických parků‚ zahrad a hřbitovů

Práce na základě analýzy venkovských a židovských hřbitovů v literatuře, archivních pramenech, ale také rozsáhlých průzkumů v terénu, charakterizuje jejich vývoj a současnou funkci jako prvku zeleně v obci. Kromě jejich urbanistické a krajinářské funkce byly hledány i formy užívání vegetačních prvků a jejich druhová skladba. Je zdůrazněna nutnost ochrany nejvýznačnějších děl minulosti. Obsahuje popis venkovských hřbitovů a židovských hřbitovů jako významných prvků zeleně v obci a jako významných krajinných prvk

Comparative Transcriptome Analysis of Two Cucumber Cultivars with Different Sensitivity to Cucumber Mosaic Virus Infection

Cucumber mosaic virus (CMV), with extremely broad host range including both monocots and dicots around the world, belongs to most important viral crop threats. Either natural or genetically constructed sources of resistance are being intensively investigated; for this purpose, exhaustive knowledge of molecular virus-host interaction during compatible and incompatible infection is required. New technologies and computer-based “omics” on various levels contribute markedly to this topic. In this work, two cucumber cultivars with different response to CMV challenge were tested, i.e., sensitive cv. Vanda and resistant cv. Heliana. The transcriptomes were prepared from both cultivars at 18 days after CMV or mock inoculation. Subsequently, four independent comparative analyses of obtained data were performed, viz. mock- and CMV-inoculated samples within each cultivar, samples from mock-inoculated cultivars to each other and samples from virus-inoculated cultivars to each other. A detailed picture of CMV-influenced genes, as well as constitutive differences in cultivar-specific gene expression was obtained. The compatible CMV infection of cv. Vanda caused downregulation of genes involved in photosynthesis, and induction of genes connected with protein production and modification, as well as components of signaling pathways. CMV challenge caused practically no change in the transcription profile of the cv. Heliana. The main differences between constitutive transcription activity of the two cultivars relied in the expression of genes responsible for methylation, phosphorylation, cell wall organization and carbohydrate metabolism (prevailing in cv. Heliana), or chromosome condensation and glucan biosynthesis (prevailing in cv. Vanda). Involvement of several genes in the resistant cucumber phenotype was predicted; this can be after biological confirmation potentially applied in breeding programs for virus-resistant crops

Stanovení zásad funkční obnovy městských a historických parků‚ zahrad a hřbitovů

Metodika architektonicko-památkového průzkumu památek zahradní architektury. Metodika byla zpracována na základě syntézy všech dostupných metodik stavebně-historických průzkumů stavebních památek a jejich urbanistických souborů a na základě syntézy obdobných průzkumů. Zahrnuje nástin historického vývoje památkové péče v ČR, provedené stavebně historické průzkumy, stavebně historický průzkum památek zahradní architektury (SHP), SHP Zámeckého parku v Telči, standardní nedestruktivní stavebně-historický průzkum, památkový rozbor území a vlastní metodiku

Asymmetrical tidal tails of open star clusters: stars crossing their cluster's prah challenge Newtonian gravitation

International audienceAfter their birth a significant fraction of all stars pass through the tidal threshold (prah) of their cluster of origin into the classical tidal tails. The asymmetry between the number of stars in the leading and trailing tails tests gravitational theory. All five open clusters with tail data (Hyades, Praesepe, Coma Berenices, COIN-Gaia 13, NGC 752) have visibly more stars within dcl = 50 pc of their centre in their leading than their trailing tail. Using the Jerabkova-compact-convergent-point (CCP) method, the extended tails have been mapped out for four nearby 600-2000 Myr old open clusters to dcl>50 pc. These are on near-circular Galactocentric orbits, a formula for estimating the orbital eccentricity of an open cluster being derived. Applying the Phantom of Ramses code to this problem, in Newtonian gravitation the tails are near-symmetrical. In Milgromian dynamics (MOND) the asymmetry reaches the observed values for 50 < dcl/pc < 200, being maximal near peri-galacticon, and can slightly invert near apo-galacticon, and the Küpper epicyclic overdensities are asymmetrically spaced. Clusters on circular orbits develop orbital eccentricity due to the asymmetrical spill-out, therewith spinning up opposite to their orbital angular momentum. This positive dynamical feedback suggests Milgromian open clusters to demise rapidly as their orbital eccentricity keeps increasing. Future work is necessary to better delineate the tidal tails around open clusters of different ages and to develop a Milgromian direct n-body code