Sökning: "photoperiod"

Visar resultat 1 - 5 av 20 avhandlingar innehållade ordet photoperiod.

  1. 1. Effects of abiotic and biotic factors on hatching, emergence and survival in Baltic salmon (Salmo salar L.)

    Författare :Eva Brännäs; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Baltic salmon; salmo salar; eggs; egg colour; alevins; fry; photoperiod; temperature; hatching; emergence pattern; synchronization; survival;

    Sammanfattning : This thesis deals with important factors that affect the temporal organization of emergence and early survival of Baltic salmon (Salmo salar L.). The study population was obtained from the Norrfors hatchery (63°50'N,20°05'E), Umeälven (Ume river) in Northern Sweden. LÄS MER

  2. 2. Seasonal variations in general activity, behaviour and cutaneous glandular structures in reindeer (Rangifer tarandus L.)

    Författare :Torgny Mossing; Umeå universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Androgen; Cervidae; dermal glands; locomotor activity olfactory communicatiorL pheromones; photoperiod; rein deer; rut; seasonal variations;

    Sammanfattning : The locomotor activity of the reindeer is separated into a diurnal and a nocturnal phase which, in turn, consists of a  number of short-term activity bursts. The onset and termination  of diurnal and nocturnal activity are largely in synchrony  with sunrise and sunset. LÄS MER

  3. 3. From growth cessation to bud burst : conifer seedling development in response to nursery culture and environmental stimuli

    Författare :Elisabeth Wallin; Högskolan Dalarna; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; Picea abies; Pinus sylvestris; Pseudotsuga menziesii; seedling status; gene activity; photoperiod; storability; vitality; transplants; shoot electrolyte leakage; Picea abies; Pinus sylvestris; Pseudotsuga menziesii; plantstatus; genaktivitet; fotoperiod; lagringsbarhet; vitalitet; omskolningsplantor; elektrolytiskt läckage; Energy; Forests and Built Environments; Energi; skog och byggd miljö;

    Sammanfattning : In Sweden, 350-400 million seedlings are produced annually for forest regeneration. About one third of these are overwintered in frozen storage, necessitating accurate methods to assess storability. Young transplants of Norway spruce (Picea abies (L.) Karst. LÄS MER

  4. 4. Genetic and experimental studies of seasonal affective disorder and related phenotypes

    Författare :Carolina Johansson; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP;

    Sammanfattning : Seasonal affective disorder (SAD) is a subtype of recurrent depressive or bipolar disorder, in which episodes reoccur and remit during a particular season each year. A genetic component in vulnerability to winter SAD has been suggested, and the goal of this thesis was to increase the understanding of SAD and seasonal variations in mood, by obtaining self-report assessments of related traits, examining genetic variations in genes hypothesised to influence the phenotypes in question, and to investigate effects of different photoperiods and stress in an animal model. LÄS MER

  5. 5. Adaptive Evolution and Demographic History of Norway Spruce (Picea Abies)

    Författare :Thomas Källman; Peter Tiffin; Uppsala universitet; []
    Nyckelord :;

    Sammanfattning : One of the major challenges in evolutionary biology is to determine the genetic basis of adaptive variation. In Norway spruce (Picea abies) the timing of bud set shows a very strong latitudinal cline despite a very low genetic differentiation between populations. LÄS MER