Occurrence of secretory structures in underground systems of seven Asteraceae species

In contrast with the abundance of anatomical studies of secretory structures on aerial vegetative organs of Asteraceae species, the information about secretory structures on thickened subterranean organs is sparse. The aim of this study was to investigate the occurrence of secretory structures on thickened and nonthickened subterranean organs of seven Asteraceae species from three tribes: Eupatorieae (Chromolaena squalida and Gyptis lanigera), Vernonieae (Chresta sphaerocephala, Lessingianthus bardanoides, L. glabratus and Orthopappus angustifolius), and Plucheeae (Pterocaulon angustifolium). The specimens were collected in areas of cerrado from the State of São Paulo, Brazil. All species of the tribe Vernonieae studied exhibited endodermic cells, other than the epithelial cells of the canal, with secretory activity in the roots. In C. sphaerocephala roots, two types of endodermic cell were found, but only one had secretory activity. Secretory canals were found in the tuberous and nontuberous roots of all studied species. These data agree with the results from the literature for Asteraceae species. Here, we describe for the first time in Asteraceae the presence of secretory idioblasts in C. sphaerocephala. Secretory trichomes are present in the Orthopappus angustifolius rhizophore. Histochemical tests have shown that all types of secretory structure possess substances containing lipids. © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society, 2008, 157 , 789–796.     

An early Miocene deep‐water decapod crustacean faunule from the Vienna Basin (Western Carpathians,Slovakia)

Abstract: A decapod crustacean faunule from the lower Miocene (upper Burdigalian, ‘Karpatian’) of the Slovakian part of the Vienna Basin comprise five new species: Callianopsis marianae (Ctenochelidae), Crosniera schweitzerae (Thomassiniidae), Agononida cerovensis and Munidopsis lieskovensis (both Galatheidae) plus Mursia harnicari (Calappidae). The new species of Callianopsis is the first undoubted member of the genus to be recorded from Europe; it is based on sexually dimorphic major and minor chelae as well as on portions of carapace and abdomen. Crosniera schweitzerae sp. nov. and Agononida cerovensis sp. nov. constitute the first fossil members of these genera. Additional material of an enigmatic crab, Styrioplax exiguus, and a re‐examination of the type material, confirms assignment of that genus to the subfamily Rhizopinae (family Pilumnidae). Palaeoecological data suggest that deposition of the levels (Lak?árska Nová Ves Formation) from which these taxa were collected took place under generally low‐energy, deep‐water conditions that were conducive to the preservation of delicate structures. Palaeobiogeographical affinities of the described taxa suggest a trans‐Atlantic migration during the early Miocene.     

Cost-effectiveness of a structured progressive task-oriented circuit class training programme to enhance walking competency after stroke: The protocol of the FIT-Stroke trial

Background  

Most patients who suffer a stroke experience reduced walking competency and health-related quality of life (HRQoL). A key factor in effective stroke rehabilitation is intensive, task-specific training. Recent studies suggest that intensive, patient-tailored training can be organized as a circuit with a series of task-oriented workstations.     

The Full Schedule of Macronuclear DNA Synthesis is Not Required for Cell Division in Paramecium tetraurelia1 1

Macronuclear DNA synthesis normally continues until late in the cell cycle in Paramecium; however, blockage of macronuclear DNA synthesis after 0.72 in the cell cycle does not alter the occurrence or timing of the subsequent cell division. When DNA synthesis is blocked after cells have reached the transition point, macronuclear DNA content at the following division is reduced to about 75% of the normal level. The point at which macronuclear DNA synthesis is no longer required for division corresponds to the beginning of micronuclear mitosis and the early stages of oral morphogenesis.     

Changes in Trypanosoma cruzi Kinetoplast DNA Minicircles Induced by Environmental Conditions and Subcloning

ABSTRACT. Reversible changes in kinetoplast DNA (kDNA) minicircles sequences were observed in clones of Trypanosoma cruzi strain Y, following a number of passages during exponential growth phase or after subcloning in blood-free medium. kDNA restriction patterns of clones were similar to those of the original uncloned strain, while subclones presented distinct kDNA restriction patterns. Homology experiments demonstrated strong hybridization between kDNA with the same electrophoretic mobility patterns while only weak signals were observed with kDNA of different patterns. The changes observed, which are unprecedented in T. cruzi clones, characterize transkinetoplastidy, and seem to be associated with similarly reversible changes both in zymodeme and in infectivity.