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Visar resultat 1 - 5 av 18 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Opioid-induced cholecystokinin release in the CNS-neurochemical mechanisms and effects of sciatic nerve lesion

    Författare :Henrik Gustafsson; Karolinska Institutet; Karolinska Institutet; []
    Nyckelord :;

    Sammanfattning : Cholecystokinin (CCK) and opioid peptides have a similar distribution in the nervous system and CCK has been demonstrated to counteract opioid-induced analgesia at spinal and supraspinal level. An increased spinal release of CCK has been suggested to be a mechanism for the relative resistance to opioid analgesic drug in certain pain conditions following nerve lesions (i. LÄS MER

  3. 2. Automorphic forms and string theory: Small automorphic representations and non-perturbative effects

    Författare :Henrik Gustafsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; instantons; automorphic forms; automorphic representations; Eisenstein series; U-duality; non-perturbative effects; string theory;

    Sammanfattning : This compilation thesis stems from a project with the purpose of determining non-perturbative contributions to scattering amplitudes in string theory carrying important information about instantons, black hole quantum states and M-theory. The scattering amplitudes are functions on the moduli space invariant under the discrete U-duality group and this invariance is one of the defining properties of an automorphic form. LÄS MER

  4. 3. Automorphic string amplitudes

    Författare :Henrik Gustafsson; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Eisenstein series; string theory; automorphic forms; U-duality; non-perturbative effects; Whittaker vectors; instantons;

    Sammanfattning : This thesis explores the non-perturbative properties of higher derivative interactions appearing in the low-energy expansion of four-graviton scattering amplitudes in toroidal compactifications of type IIB string theory. We summarise the arguments for finding such higher derivative corrections in terms of automorphic forms using U-duality, supersymmetry and string perturbation theory. LÄS MER

  5. 4. Burnout in competitive and elite athletes

    Författare :Henrik Gustafsson; Peter Hassmén; Göran Kenttä; Thomas Raedeke; Örebro universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; athlete identity; burnout; case-study; elite athletes; overtraining; self-esteem; stress; Sports; Idrott; Idrottsvetenskap; Sports Science; Idrottsvetenskap;

    Sammanfattning : Intensified training regimes and increasing competitive pressure make some athletes leave sports with shattered hopes and dreams. A number of these athletes drop out of sports due to burnout, which is characterized by an enduring experience of emotional and physical exhaustion, reduced sense of accomplishment and devaluation of sport participation as a consequence of prolonged chronic stress. LÄS MER

  7. 5. Degenerate Geometries, Supersymmetry and Duality

    Författare :Henrik Gustafsson; Marcus Grisary; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; fysik;

    Sammanfattning : String theory is a theory attempting to unify gravity with the electro-weak and strong interactions so successfully described by Quantum Field Theory. The implications of String Theory is not fully understood since it is still not a complete theory. LÄS MER