Search results for "SWI"
showing 10 items of 1473 documents
Movement dependent position changes of the antennular flagellum ofPalaemon xiphias (Risso)
1977
The angular positions of the outer flagellum ofPalaemon xiphias were obtained by cinematographic measurements during different phases of locomotion. Contrary to the upright resting position the flagella are stretched forward into a distinct starting position preliminary to any forward movement, and then pushed down with acceleration of swimming speed. These phenomena are discussed in context with comparable behaviour in other decapods and in insects.
Mentoring of newly qualified teachers. A bilateral comparison between Germany and Finland
2017
Mentoring stellt in der Begleitung von in den Beruf einsteigenden Lehrpersonen eine international gängige Praxis dar. Ausgehend von theoretischen und empirisch fundierten Annahmen wird in diesem Beitrag der Ansatz der practice architectures genutzt, um Formen des Mentorings in Deutschland und Finnland im Hinblick auf länderspezifische Verständnisse vom Berufseinstieg von Lehrpersonen und deren Professionalisierung zu untersuchen. (DIPF/Orig.) Internationally, mentoring is a well-recognized practice in supporting newly qualified teachers. Based on theoretical and empirical understanding, this paper compares mentoring practices in two countries: Germany and Finland. The theoretical framework …
Two-carbon bridge substituted cocaines: enantioselective synthesis, attribution of the absolute configuration and biological activity of novel 6- and…
1999
In an effort to learn more about the general structure-activity relationships of cocaine with the aim to elucidate those structural features that might confer antagonistic properties to such analogues, we describe herein our synthetic efforts to prepare two-carbon bridge functionalized (methoxylated and hydroxylated) analogues. Our approach makes use of a modification of the classical Willstatter synthesis of cocaine: Mannich type cyclization of acetonedicarboxylic acid monomethyl ester with methylamine hydrochloride and 2-methoxysuccindialdehyde in a citrate buffer solution afforded the 6- and 7-substituted 2-carbomethoxy-3-tropinones 3a,b and 4a,b in approximate yields of 64%. Reduction o…
QUALITATIVE AND QUANTITATIVE BEHAVIORAL TRAITS IN A COMMUNITY OF FURCOCERCARIAE TREMATODES: TOOLS FOR SPECIES SEPARATION?
2008
Many trematode cercariae show distinct behavioral features, which have commonly been used in species identification in combination with morphological characteristics. However, information regarding cercariae behavior has often not been quantified in detail, or it is scattered in the literature, which is why the appropriate level of precision in behavioral identity, particularly in groups of cercariae species showing considerable morphological overlap, has not been properly established. In this study, we investigated one such group, the furcocercariae trematodes, by studying their behavior in a community consisting of 8 species (Diplostomum pseudospathaceum, Ichthyocotylurus variegatus, Coty…
Essential versus accessory aspects of cell death: recommendations of the NCCD 2015
2015
Cells exposed to extreme physicochemical or mechanical stimuli die in an uncontrollable manner, as a result of their immediate structural breakdown. Such an unavoidable variant of cellular demise is generally referred to as ?accidental cell death' (ACD). In most settings, however, cell death is initiated by a genetically encoded apparatus, correlating with the fact that its course can be altered by pharmacologic or genetic interventions. "Regulated cell death" (RCD) can occur as part of physiologic programs or can be activated once adaptive responses to perturbations of the extracellular or intracellular microenvironment fail. The biochemical phenomena that accompany RCD may be harnessed to…
Determination of biogenic amines in meat by combined ion-exchange capillary gas chromatography
1984
Abstract A procedure is described for the determination of putrescine, cadaverine and histamine in meat. Crude perchloric acid extracts were pre-separated on a weakly acidic cation exchanger and the amines quantified by capillary gas chromatography. The diamines were analysed as trifluoroacetyl derivatives and histamine was converted into N α -trifluoroacetyl-N τ -ethoxycarbonylhistamine. The accuracy of the determination of diamines was examined by a precipitation pre-separation method and by mass fragmentometric quantification. The proposed procedure allows the sensitive, sufficiently precise and highly specific determination of putrescine and cadaverine in meat.
A photoswitchable helical peptide with light-controllable interface/transmembrane topology in lipidic membranes
2021
Summary The spontaneous insertion of helical transmembrane (TM) polypeptides into lipid bilayers is driven by three sequential equilibria: solution-to-membrane interface (MI) partition, unstructured-to-helical folding, and MI-to-TM helix insertion. A bottleneck for understanding these three steps is the lack of experimental approaches to perturb membrane-bound hydrophobic polypeptides out of equilibrium rapidly and reversibly. Here, we report on a 24-residues-long hydrophobic α-helical polypeptide, covalently coupled to an azobenzene photoswitch (KCALP-azo), which displays a light-controllable TM/MI equilibrium in hydrated lipid bilayers. FTIR spectroscopy reveals that trans KCALP-azo folds…
Er:Cr:YSGG laser with electrooptic PLZT ceramics Q-switching Fabry-Perot interferometer output mirror
2001
Summary form only given. Q-switching of Er:Cr:YSGG laser with transparent PLZT ceramics electro-optic modulators was reported previously. The extremely large quadratic EO effect in PLZT allows to build small size moderate control voltages. The high induced birefringence in PLZT results from an essential contribution to polarization (and consequently to the birefringence) of processes with longer relaxation times up to seconds, corresponding to the Er:Cr:YSGG laser operating rate. PLZT ceramics have also a high value of the refractive index (n /spl ap/ 2.2-2.3 for /spl lambda/ = 3 /spl mu/m, slightly depending on PLZT composition and temperature) and thus considerable Fresnel reflections R/s…
Spectrofluorimetric Quantification of Malondialdehyde for Evaluation of Cyclooxygenase-1/Thromboxane Synthase Inhibition
1999
The in vitro assay developed by Hartmann and Ledergerber (1995) utilizing the spectrofluorimetric quantification of malondialdehyde after reaction with thiobarbituric acid was modified and used for further investigations. The human whole blood was replaced by a platelet suspension of pig blood, and calcium ionophore A23187 was used instead of collagen for inducing the arachidonic acid cascade. The modified assay represents a simple, time and cost saving method for the evaluation of cyclooxygenase-1/thromboxane synthase inhibition. The reproducibility and comparability of results is given. Additional experiments allow classification of selective phospholipase A2, cyclooxygenase-1, and thromb…
Relationships between host species and morphometric patterns in Fasciola hepatica adults and eggs from the northern Bolivian Altiplano hyperendemic r…
2001
The highest prevalences and intensities of human fasciolosis by Fasciola hepatica are found in the northern Bolivian Altiplano, where sheep and cattle are the main reservoir host species and pigs and donkeys the secondary ones. Morphometric comparisons of many linear measurements, areas and ratios of F. hepatica adults (from sheep, cattle and pigs) and eggs (from sheep, cattle, pigs and donkeys) in natural liver fluke populations of the Bolivian Altiplano, as well as of F. hepatica adults and eggs experimentally obtained in Wistar rats infected with Altiplanic sheep, cattle and pig isolates, were made using computer image analysis and an allometric model. Although morphometric values of adu…