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Visar resultat 1 - 5 av 357 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Optimal thinning : a theoretical investigation on individual-tree level

    Författare :Peter Fransson; Åke Brännström; Ola Lindroos; Oskar Franklin; Per Lundberg; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; Forest management; Simulation; Optimization; Spatially explicit model; Individual-based model;

    Sammanfattning : Paper I: In paper I, we asked how a tree should optimally allocate its resources to maximize its fitness. We let a subject tree grow in an environment shaded by nearby competing trees. The competitors were assumed to have reached maturity and had stopped growing, thus creating a static light environment for the subject tree to grow in. LÄS MER

  3. 2. Early life environmental exposures and children's growth : A longitudinal study evaluating prenatal exposure for endocrine disrupting chemicals and nutrition in relation to children's growth up to seven years of age

    Författare :Katherine Svensson; Carl-Gustaf Bornehag; Sverre Wikström; Chris Gennings; Alicja Wolk; Marie Löf; Karlstads universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Endocrine disrupting chemicals; EDC; Nutrition; Pregnancy; Children; Growth; Birthweight; Body composition; Body Fat; BMI; Overweight; Public Health Science; Folkhälsovetenskap;

    Sammanfattning : Endocrine disrupting chemicals (EDCs) have the potential to disrupt the endocrine system in humans and animals with importance for health and development. Additionally, optimal nutrition during pregnancy is critical for fetal growth and pregnancy outcomes. LÄS MER

  4. 3. Test Design for Mean Ability Growth and Optimal Item Calibration for Achievement Tests

    Författare :Jonas Bjermo; Frank Miller; Marie Wiberg; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; test design; item response theory; optimal experimental design; SweSAT; item calibration; vertical scaling; ability growth; computerized adaptive tests; Statistics; statistik;

    Sammanfattning : In this thesis, we examine two topics in the area of educational measurement. The first topic studies how to best design two achievement tests with common items such that a population mean-ability growth is measured as precisely as possible. The second examines how to calibrate newly developed test items optimally. LÄS MER

  5. 4. On the binding of growth-promoting polyamines to proteoglycans: Implications for growth-regulation and polycation-mediated gene transfer

    Författare :Mattias Belting; Institutionen för experimentell medicinsk vetenskap; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Genetics; cationic lipid.; gene transfer; gene therapy; cell growth; polyamine transport; spermine; polyamine; growth-inhibition; heparan sulphate; dermatan sulphate; Proteoglycan; glycosaminoglycan; cytogenetics; Genetik; cytogenetik;

    Sammanfattning : Initial investigations were directed at studying the interaction between polyamines and various glycosaminoglycans (GAGs). The polyamine spermine displayed binding to dermatan sulphate (DS) and heparan sulphate (HS) with similar (Kd, 3.9 x 10-4 M) and higher (Kd, 0.37 x 10-6 M) affinity, respectively, than to DNA. LÄS MER

  7. 5. Pre-, peri- and postnatal influences on ophthalmologic outcome - a study on children born after intracytoplasmic sperm injection (ICSI) and children born preterm

    Författare :Margareta Hök Wikstrand; Göteborgs universitet; []
    Nyckelord :visual function; intracytoplasmic sperm injection; preterm birth; growth; insulin-like growth factor 1; postnatal development; ocular fundus morphology;

    Sammanfattning : The aims of the present study were to investigate the effects of prenatal factors in children born after intracytoplasmic sperm injection (ICSI) and peri- and postnatal factors in children born preterm on visual function and ocular fundus morphology at school age. In the children born preterm the ophthalmologic outcomes, including optic nerve morphology were analysed in relation to gestational age (GA), birth weight (BW) standard deviation score (SDS), serum levels of insulin-like growth factor I (IGF-I), weight at week 32 (SDS), and weight, length and head circumference (SDS) at school age. LÄS MER