Sökning: "sperm morphology"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden sperm morphology.

1. 1. Gonad and ejaculate allocation in alternative reproductive tactics of salmon and trout with reference to sperm competition

   Författare :Tomislav Vladić; Michael Taborsky; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; alternative reproductive tactics; sperm competition; brown trout; Atlantic salmon; ATP; ejaculate expenditure; motility; sperm morphology; trade-off; loaded raffle; zoologi; Zoology;

   Sammanfattning : Atlantic salmon, Salmo salar L., and brown trout, Salmo trutta L., exhibit alternative male maturation phenotypes, anadromous and precociously mature parr, which commonly endure in sperm competition at the spawning grounds. LÄS MER

3. 2. Choice, competition, and interactions between episodes of sexual selection

   Författare :Charel Reuland; John Fitzpatrick; Ingo Schlupp; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; contest competition; sperm competition; mate choice; cryptic choice; sperm quality; reproductive status; social dominance; etologi; Ethology;

   Sammanfattning : Choice and competition are essential parts of evolutionary biology. In an effort to pass their genes from one generation to the next, animals may carefully choose their mating partners, and/or compete for access to mates. LÄS MER

4. 3. Phylogeny and Taxonomy of Childia (Acoela) : New characters for unraveling acoel phylogenies from molecules, ultrastructure, immunocytochemistry and confocal microscopy

   Författare :Yonas Isaak Tekle; Ulf Jondelius; Mikael Thollesson; Isabel Sanmartin; Kennet Lundin; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Biology; Childiidae; Childia; Paraphanostoma; Acoela; phylogeny; taxonomy; morphology; 18S rRNA; 28S rRNA; Histone H3; ultrastructure; confocal; phalloidin; immunocytochemistry; Biologi; Biology; Biologi;

   Sammanfattning : This thesis presents a comprehensive phylogenetic and taxonomic study of an acoel subgroup, the Childiidae. Members of this taxon are characterized by well-developed male copulatory organs with conical/cylindrical stylets. LÄS MER

5. 4. 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

7. 5. Studies on genetic aberrations as possible predictors of the outcome of assisted reproduction

   Författare :Mona Bungum; Malmö Reproduktionsmedicin; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; assisted reproduction; IUI; Sperm chromatin; ICSI; intra-individual variation; fertilisation failure genetic aberration; Protein C inhibitor gene; sperm DNA damage SCSA; IVF;

   Sammanfattning : Traditionally, diagnosis of male infertility has relied upon microscopic assessment of semen. The normality criteria set by the World Health Organization (WHO) in regard to sperm concentration, motility and morphology are, however, poor predictors of fertility. LÄS MER