Sökning: "phototaxis"

Visar resultat 1 - 5 av 6 avhandlingar innehållade ordet phototaxis.

  1. 1. The surface complex of Euglena gracilis. Involvement in cellular movements and biochemical and molecular analyses of the components

    Författare :Silja K Petersen-Mahrt; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; UV-B radiation; tubulin; surface complex; plasma membrane; phylogeny; phototaxis; nitrogen deficiency; membrane skeleton; Euglena gracilis; actin; cell shape; Physiological biophysics; Växtfysiologi;

    Sammanfattning : The flagellate Euglena gracilis shows rhythms in phototaxis and cell shape changes between oblong and round. Artificial UV-B radiation of 0.5 W m-2 caused a loss in phototaxis, but the peak of activity occurred at the same time as for control cells. LÄS MER

  3. 2. Neural mechanisms for the visual control of spatial orientation and locomotion : electrophysiological and behavioural studies of the supraspinal control of posture and steering in the lamprey central nervous system, with reference to visuo-motor mechanisms

    Författare :Fredrik Ullén; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : Neural mechanisms for the supraspinal control of posture and steering, in particular visuo-motor control and visuo-vestibular interaction in postural control, were investigated, using the lamprey as a model system. Behavioural experiments on intact and chronically lesioned animals, intra- and extracellular recordings in vitro and retrograde staining of neurons with horseradish peroxidase were utilized. LÄS MER

  4. 3. Getting to know Trioza apicalis (Homoptera: Psylloidea) – a Specialist Host-Alternating Insect with a Tiny Olfactory System

    Författare :Lina Kristoffersen; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physiology of invertebrates; Djurs anatomi och morfologi; Entomologi; plant parasitology; Entomology; Ekologi; Ecology; glomeruli; antennal lobe; olfactory receptor neurons electrophysiology; antennae; behaviour; olfaction; Sternorrhyncha; psyllid; Ryggradslösa djurs fysiologi; animal morphology; Animal anatomy; växtparasitologi;

    Sammanfattning : This thesis comprises ecological, morphological and physiological studies of the carrot psyllid Trioza apicalis (Homoptera: Psylloidea) with particular focus on olfaction. Data from inventories of winter habitats suggest that T. apicalis prefer Picea abies over Pinus sylvestris and Juniperus communis as winter hosts. LÄS MER

  5. 4. Energy Transduction and Sensory Signalling in Haloarchaea Structural Characterisation of the Photocycles of Bacteriorhodopsin and Sensory Rhodopsin II

    Författare :Karl Edman; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; kinetic crystallography; proton pumping; Haloarchaea; structural mechanism; bacteriorhodopsin; sensory signalling; sensory rhodopsinII; retinal proteins;

    Sammanfattning : Archaeal rhodopsins belong a subfamily of heptahelical transmembrane proteins. All contain a buried retinal chromophore covalently bound to a conserved lysine residue in helix G via a protonated Schiff base. LÄS MER

  7. 5. Spatial vision in diverse invertebrates

    Författare :John Kirwan; Funktionell zoologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; vision; visual ecology; invertebrates; spatial resolution; behaviour;

    Sammanfattning : Light-detection provides incomparabaly rapid information at a range of time scales and, consequently, directional photoreception is found in almost every major metazoan clade. Conversely, a much smaller cohort have evolved sophisticated high resolution vision, which facillitates complex tasks via the detection of fast or small objects,. LÄS MER