Absence of promoting potential of bracken fern (Pteridium aquilinum) in rat urinary bladder carcinogenesis induced by N-butyl-N-(4-hydroxybutyl)-nitrosamine and uracil

Conventional studies on bracken fern (Pteridium aquilinum; PA) carcinogenicity have used high dietary concentrations (around 30%) and long-term exposure (up to 52-70 weeks) without consideration of the multistep character of the chemical carcinogenesis process. The present study evaluated specifically the promoting potential of 3-5% dietary crude PA in the rat urinary bladder mucosa in a 32-week-long initiation-promotion assay for chemical carcinogenesis. Initiation of urothelial carcinogenesis was accomplished with N-butyl-N-(4-hydroxybutyl)-nitrosamine (BBN). Uracil (U) was provided through the diet in order to expand the population of initiated cells. Seven groups (C) of male Wistar rats were submitted to the following treatments: G1 = BBN (n = 8); G2 = U (n = 10); G3 = BBN-U (n = 9); G4 = BBN-PA-U-PA (n = 16); G5 = PA (n = 8); G6 = BBN-PA (n = 10); G7 = PA-U-PA (n = 12). At the end of the experiment rats presenting epithelial papillary or nodular hyperplasia (PNH), papillomas (PAP), or simultaneous PNH plus PAP numbered, respectively G1: 2-0-1; G2: 0-0-0; G3: 3-0-2; G4: 4-3-2; G5: 1-0-1; G6: 8-0-0; and G7: 0-0-0, with no significant differences in the incidence of lesions among the groups. More frequent and more severe lesions occurred in BBN-initiated animals, predominantly in those also exposed to uracil (G3 and G4). Low-dose crude bracken fern in the diet does not promote rat urinary bladder carcinogenesis after a 32-week period of exposure, even when the initiated urothelial cell population has been expanded through a mechanical stimulus. (C) 1995 Wiley-Liss, Inc.

Influence of light, plant density and disinfection in spore germination of fern blechnum brasiliense desv. blechnaceae

The present assay had as objective evaluating spore germination of Blechnum brasiliense in relation to light, plant density and disinfection. The assay was carried out at Jaboticabal, Sào Paulo State, Brazil, from February, 22 to June, 30, 1996. The experimental design was randomized blocks on a factorial scheme (3x2x2), consisting of 12 treatments, three environments (shade-house, dark-house and germination camera), 2 densities (0.005 grs and 0.010 grs of spores/treatment) and presence or absence of disinfection. The leaf coverage area (130 days) and the number of days necessary to germinate were evaluated. The germination camera data were not analysed because they were insignificant; consequently, the remining data were analysed on a 2×2×2 scheme. The shade-house provided larger green covering area and a faster germination. The density of 0.0 lOg of spore/treatments presented the largest green covering area. The supply of partial light was necessary for good germination. The interaction between the environment and the density had significant effect on the green covering area.

Ernest Meissonier und der Blick durch die Lupe - Fern- und Nahsicht im französischen Salon

Während angesichts der Gemälde der Impressionisten immer wieder geäußert wurde, dass diese sich nur aus großem Abstand betrachten ließen, meinten viele Besucher des französischen Salons, den kleinformatigen Gemälden Ernest Meissoniers nur durch einen Blick durch die Lupe gerecht werden zu können. Der vorliegende Essay geht der rezeptionsästhetischen Frage nach, inwieweit die besondere Betrachtungsweise der Gemälde Meissoniers durch die Bilder selbst konditioniert wurde. Zunächst wird dabei auf die Regeln einzugehen sein, welche die zeitgenössische Kunsttheorie hinsichtlich des richtigen Betrachterabstands aufgestellt hatte, um sodann eine exemplarische Auswahl der Gemälde des Künstlers näher ins Visier zu nehmen. Schließlich sollen die Ergebnisse im Kontext der zeitgenössischen Rezeptionsbedingungen, wie sie der französische Salon vorgab, diskutiert werden.

Ernest Meissonier und der Blick durch die Lupe - Fern- und Nahsicht im französischen Salon

Während angesichts der Gemälde der Impressionisten immer wieder geäußert wurde, dass diese sich nur aus großem Abstand betrachten ließen, meinten viele Besucher des französischen Salons, den kleinformatigen Gemälden Ernest Meissoniers nur durch einen Blick durch die Lupe gerecht werden zu können. Der vorliegende Essay geht der rezeptionsästhetischen Frage nach, inwieweit die besondere Betrachtungsweise der Gemälde Meissoniers durch die Bilder selbst konditioniert wurde. Zunächst wird dabei auf die Regeln einzugehen sein, welche die zeitgenössische Kunsttheorie hinsichtlich des richtigen Betrachterabstands aufgestellt hatte, um sodann eine exemplarische Auswahl der Gemälde des Künstlers näher ins Visier zu nehmen. Schließlich sollen die Ergebnisse im Kontext der zeitgenössischen Rezeptionsbedingungen, wie sie der französische Salon vorgab, diskutiert werden.

Verordnung in wie fern den zweiten Juden-Söhnen der Landesherrliche Schutz ...

Wilhelm, L. z. H.

An die Herren Urwähler zur ersten Kammer in der 42. bis 45. und 48. Wahlabtheilung: Die Wahl der Wahlmänner für die erste Kammer ist nicht mehr fern ...

Welsch (Projektbearbeiter): Einladung an die Wahlglieder der Berliner Wahlbezirke 42 bis 45 und 48 zur Vorberatung über die Ausübung des Urwählerrechts für die erste Kammer

Is fern endozoochory widespread among fern-eating herbivores?

Endozoochory is an important dispersal mechanism for seed plants and has recently been demonstrated to occur also in spore plants, such as ferns, which are commonly consumed by herbivores. However, it is not known whether fern species from particular habitats are differentially preferred by herbivores and whether their spores differ in their ability to survive the gut passage of herbivores. Such differences would suggest adaptation to endozoochorous dispersal, as it is known for seed plants. Moreover, it is unclear whether herbivore species differ in their efficiency to disperse fern spores. In a factorial experiment, we fed fertile leaflets of 13 fern species from different forest and open habitats to three polyphagous herbivore species and recorded the germination of spores from feces after 46 and 81 days. Fern spores germinated in 66 % of all samples after 46 days. At this stage, germination success differed among fern and herbivore species, but was independent of the ferns’ habitat. Interestingly, after 81 days fern spores germinated in 85 % of all samples and earlier significant differences in germination success among fern and herbivore species were not sustained. The overall high germination success and the absence of differences among fern species from different habitats together with the consistency across three tested herbivores strongly imply endozoochorous dispersal to be a taxonomically widespread phenomenon among fern-eating herbivores, which all might act as potential dispersal vectors. © 2015, Springer Science+Business Media Dordrecht.

Ein schön news Geystliches Lied : Ach Gott was sol ich singen, mein frewd die ist mir fern, [etc.]

In Fraktur

The Fern-like seed-plants of the carboniferous flora

By D. H. Scott

Fern Andra, Ganzfigurbildnis

Signatur des Originals: S 36/F02583

Characterization of MADS homeotic genes in the fern Ceratopteris richardii

The MADS genes encode a family of transcription factors, some of which control the identities of floral organs in flowering plants. To understand the role of MADS genes in the evolution of floral organs, five MADS genes (CMADS1, 2, 3, 4, and 6) were cloned from the fern Ceratopteris richardii, a nonflowering plant. A gene tree of partial amino acid sequences of seed plant and fern MADS genes showed that the fern genes form three subfamilies. All members of one of the fern MADS subfamilies have additional amino-terminal amino acids, which is a synapomorphic character of the AGAMOUS subfamily of the flowering plant MADS genes. Their structural similarity indicates a sister relationship between the two subfamilies. The temporal and spatial patterns of expression of the five fern MADS genes were assessed by Northern blot analyses and in situ hybridizations. CMADS1, 2, 3, and 4 are expressed similarly in the meristematic regions and primordia of sporophyte shoots and roots, as well as in reproductive structures, including sporophylls and sporangial initials, although the amount of expression in each tissue is different in each gene. CMADS6 is expressed in gametophytic tissues but not in sporophytic tissues. The lack of organ-specific expression of MADS genes in the reproductive structures of the fern sporophyte may indicate that the restriction of MADS gene expression to specific reproductive organs and the specialization of MADS gene functions as homeotic selector genes in the flowering plant lineage were important in floral organ evolution.