Sökning: "biological vision"

Visar resultat 1 - 5 av 82 avhandlingar innehållade orden biological vision.

  1. 1. Ommatidial adaptations for vision in nocturnal insects

    Författare :Rikard Frederiksen; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Gain of transduction; Information rate; Signal-to-noise ratio; Apposition eye; Optical sensitivity; Nocturnal insects; Superposition eye; Vision;

    Sammanfattning : Nocturnal vision is a demanding task for insects with small eyes. As it gets dimmer the noise imposed by the stochastic nature of photon arrival makes vision unreliable. Despite this, there are quite a number of animal species that are active at night and apparently see well. LÄS MER

  3. 2. Evolution of Vertebrate Vision by Means of Whole Genome Duplications : Zebrafish as a Model for Gene Specialisation

    Författare :David Lagman; Dan Larhammar; Xesús M Abalo; Finn Hallböök; Stephan Neuhauss; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; phylogenetics; evolution; vision; visual opsin; transducin; PDE6; genome duplications; subfunctionalisation; Medicinsk vetenskap; Medical Science;

    Sammanfattning : The signalling cascade of rods and cones use different but related protein components. Rods and cones, emerged in the common ancestor of vertebrates around 500 million years ago around when two whole genome duplications took place, named 1R and 2R. LÄS MER

  4. 3. Superior Underwater Vision in Humans

    Författare :Anna Gislén; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; taxonomy; zoogeography; Zoologisk systematik; djurgeografi; Systematic zoology; contrast sensitivity; spatial vision; Accommodation; pupil;

    Sammanfattning : Amphibious vision is accomplished in many animals by special optical and physiological adaptations in the eyes. However, human eyes are considered to be adapted to a life in air since our curved outer cornea – which is used to refract more than two-thirds of the incoming light on land – becomes useless underwater. LÄS MER

  5. 4. Bird Vision: Spatial acuity and colour discrimination in bright and dim light

    Författare :Olle Lind; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Animal vision; Visual ecology; Colour vision; Spatial acuity; Spatial contrast sensitivity; Dim light; Visual modelling; Behavioural experiments; Birds; Psittaciformes;

    Sammanfattning : Birds use vision to guide navigation, foraging and mate choice, and studies of the limitations in bird visual perception are most helpful for the understanding of bird ecology. Here, I present four studies of bird vision in bright and dim light. 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