Search results for "Digitalis"

Digitalis purpurea P5 beta R2, encoding steroid 5 beta-reductase, is a novel defense-related gene involved in cardenolide biosynthesis.

2009

The stereospecific 5 beta-reduction of progesterone is a required step for cardiac glycoside biosynthesis in foxglove plants. Recently, we have isolated the gene P5 beta R, and here we investigate the function and regulation of P5 beta R2, a new progesterone 5 beta-reductase gene from Digitalis purpurea. P5 beta R2 cDNA was isolated from a D. purpurea cDNA library and further characterized at the biochemical, structural and physiological levels. Like P5 beta R, P5 beta R2 catalyzes the 5 beta-reduction of the Delta(4) double bond of several steroids and is present in all plant organs. Under stress conditions or on treatment with chemical elicitors, P5 beta R expression does not vary, wherea…

Understanding the influence of context in technology integration from teacher educators’ perspective

2021

The perspective of teachers is important for advancing the use of technology in classrooms. A considerable number of research studies have explained context in ways that have narrowed the understanding of its impact on successful technology integration. This study employs the Technological Pedagogical and Content Knowledge (TPACK) model as a lens in understanding factors influencing teachers’ integration of technology in classrooms. Data were collected using focused interviews of 19 teacher educators of three colleges of education from the southern part of Nigeria. The results reveal that among the level contexts, the meso level presented the most challenges to teachers’ efforts at integrat…

The CDIO Syllabus 3.0 - An Updated Statement of Goals

2022

The CDIO Initiative is going through a process of reconsidering and updating the CDIO approach for engineering education development. Previous work resulted in substantial updates of the twelve CDIO standards and the introduction of “optional” CDIO standards. This paper reports on a similar review and update of the CDIO Syllabus to version 3.0. It has been developed by a working group consisting of four sub-groups and iterated and refined guided by feedback from the whole CDIO community. There are mainly three external drivers that 18 Proceedings of the 18th International CDIO Conference, hosted by Reykjavik University, Reykjavik Iceland, June 13-15, 2022. motivate the changes: sustainabili…

�ber den Einflu� von Digitoxigenin auf das Aktionspotential des Vorhofs euthyreoter und hyperthyreoter Meerschweinchen bei experimentellen Insuffizie…

1961

An isolierten Herzohren von Meerschweinchen wurden intracellulare Aktionspotentiale unter gleichzeitiger Registrierung der Kontraktionen abgeleitet. Untersucht wurde der Einflus des Digitoxigenins nach Barbituratschadigung und unter Calciummangel bei euthyreoten und hyperthyreoten Tieren.

�ber die Wirkung von Digitoxigenin auf den cellul�ren Calcium-Umsatz im Herzmuskelgewebe

1962

Vergleichende Untersuchungen �ber die Wirkung verschiedener Digitoxigeninderivate auf die Kontraktionskraft und den Ca-Austausch isolierter Meerschwe…

1963

An isolierten, elektrisch gereizten Meerschweinchenvorhofen wurde das Verhalten der Kontraktionskraft und des cellularen Ca-Haushaltesunter dem Einflus von Digitoxigenin, Dihydrodigitoxigenin und 3α-Digitoxigenin uber einen weiten Dosierungsbereich vergleichend untersucht. Diese Substanzen zeigten betrachtliche Unterschiede in der Intensitat ihrer positiv inotropen und kontrakturerzeugenden Wirkung. Im positiv inotropen Dosierungsbereich verhielten sich die aquieffektiven Konzentrationen von Digitoxigenin, Dihydrodigitoxigenin und 3α-Digitoxigenin etwa wie 1:20:70. Bei der Messung des transmembranen Ca-Austausches mit 47Ca ergab sich unter Kontrollbedingungen eine nur partielle Markierbarke…

Quantitative Untersuchungen am Meerschweinchenvorhof �ber die Abh�ngigkeit der Digitoxigenin wirkung von der extracellul�ren Calciumkonzentration

1963

Es wurde uber einen weiten Bereich die Calciumkonzentration der Tyrodelosung verandert (0,9–9,0 mAq/l) und unter diesen Bedingungen die Konzentrationswirkungsbeziehungen fur verschiedene Digitoxigenindosen (1 × 10−7, 3 × 10−7, 5 × 10−7, 7 × 10−7 und 1 × 10−6 g/ml) am Meerschweinchenvorhof untersucht. Aus den Befunden geht hervor, das uber den gesamten untersuchten Bereich unter therapeutischen und toxischen Bedingungen ein eindeutiger Wirkungszusammenhang zwischen Digitoxigenin und Calcium besteht.

Morphogenesis and Cardenolide Formation in Digitalis obscura Cultures

1991

Summary Cardenolide formation was investigated in hypocotyl cultures of Digitalis obscura L. established on MS medium with growth regulators selected to promote either callus formation, caulogenesis, embryogenesis or rhizogenesis. Examination of the cardenolide composition of leaves from mature plants was also performed. Several compounds of series A and C were identified by HPLC in in vitro and in vivo grown tissues, no marked differences being found between their cardenolide patterns. RIA determinations showed that shoot- or embryo-forming calli accumulated significantly higher amounts of digoxigenin derivatives than undifferentiated or rhizogenic cultures. In any case, field plants prese…

SOIL CHARACTERISTICS, MINERAL NUTRIENTS, BIOMASS, AND CARDENOLIDE PRODUCTION INDIGITALIS OBSCURAWILD POPULATIONS

2002

Mature leaves of wild-growing Digitalis obscura plants and soil samples were collected in four different regions. Soil and leaf mineral nutrient contents as well as biomass and cardenolide productions were determined. The soils in the four collection sites, basic and highly calcareous, showed significant interpopulation differences in phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), manganese (Mn), copper (Cu), and zinc (Zn). Foliar mineral nutrients and cardenolides also varied among populations. Highest cardenolide yield was found in those Digitalis populations presenting a better development. The cardenolide content exhibited significant negative correlations with the levels …

Human-technology relations in an age of surveillance capitalism. Towards an anthropological theory of the dialectic between analogue and digital huma…

2021

What can anthropology contribute to the current debates about the negative effects of social media on people? Starting from a critique of anthropological work that sees human subjectivity and culture as ontologically unaffected by social media use, I propose that human engagement with these digital technologies produces significant ontological transformations that deserve more attention. I develop my analysis in dialogue with Boellstorff’s ontology of the digital, Nardi’s theorisation of virtuality and affordances, and Zuboff’s formulation of surveillance capitalism, and I use empirical illustrations from the Cambridge Analytica data scandal to highlight key theoretical junctures. My main c…