Sökning: "Compound Eyes"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden Compound Eyes.

  1. 1. The visual ecology of bees - Tales of diverse eyes and behaviours

    Författare :Pierre Tichit; Funktionell zoologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Animal behaviour; Arthropods; Bumblebees; Compound Eyes; Crystalline cones; Flight control; Image analysis; Landing; Sensory ecology; Stingless bees; Vision; X-ray microtomography;

    Sammanfattning : The buzzing flight of bees is a popular summer hit. Yet, outside of a few familiar species of honeybees and bumblebees, these fantastic little creatures are still mostly unknown. With about twenty-five thousand species, bees are a very diverse group. They can be found in drastically different habitats. LÄS MER

  2. 2. Visual ecology of insect superposition eyes

    Författare :Pär A Brännström; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Animal physiology; tiger beetle; hawkmoth; mayfly; insect; visual ecology; eye design; vision; compound eye; Djurfysiologi;

    Sammanfattning : In the superposition compound eye each rhabdom (light sensitive unit) receives light through many ommatidial facets, while in the apposition compound eye every rhabdom receives light from a single facet. The superposition design increases photon capture, which is an advantage in dark environments. LÄS MER

  3. 3. Adaptations for nocturnal vision in insect apposition eyes

    Författare :Birgit Greiner; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; temporal and spatial summation; optical and neural adaptations; theoretical modelling.; Djurs anatomi och morfologi; Zoologi; dim light; vision; landmark navigation; nocturnal bees and wasps; Zoology; Animal anatomy; animal morphology;

    Sammanfattning : Due to our own preference for bright light, we tend to forget that many insects are active in very dim light. The reasons for nocturnal activity are most easily seen in tropical areas of the world, where animals face severe competition for food and nocturnal insects are able to forage in a climate of reduced competition and predation. LÄS MER

  4. 4. 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

  5. 5. Virtual histology by laboratory x-ray phase-contrast tomography

    Författare :Jenny Romell; Hans Hertz; Anna Burvall; Julia Herzen; KTH; []
    Nyckelord :MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Biological and Biomedical Physics; Biologisk och biomedicinsk fysik;

    Sammanfattning : Detailed imaging of biological samples is central to different fields of research, as well as for clinical pathology. Classical histology, using light- orelectron microscopy, can generate high-resolution images but is destructive and only gives two-dimensional information. LÄS MER