Sökning: "sperm"

Visar resultat 1 - 5 av 144 avhandlingar innehållade ordet sperm.

1. 1. Selection in sperm and its consequences : Exploring haploid selection, ageing and epigenetic effects in sperm

   Författare :Cosima Hermans Née Hotzy; Simone Immler; Göran Arnqvist; Mariana Wolfner; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; sperm; evolution; selection; haploid selection; epigenetics; sperm-mediated effects; trans-generational effects; sperm ageing; sperm senescence;

   Sammanfattning : Sexually reproducing eukaryotes are typically going through a biphasic life cycle with a diploid and a haploid phase. Unlike in plants where selection on haploid pollen genotypes is well established, the possibility of selection occurring in animal sperm is currently not known. LÄS MER

3. 2. Sperm Whales : Social Organization and Global Genetic Structure

   Författare :Thomas Lyrholm; Mark Stoneking; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; zoologi; Zoology;

   Sammanfattning : The social organization of most mammals is characterised by female philopatry and male dispersal. This thesis examines the social organization of sperm whales, Physeter macrocephalus, using a combination of field observations and molecular genetic techniques. LÄS MER

4. 3. Sex, Sperm and Speciation : On sexual selection and fertility in hybridizing flycatchers

   Författare :Murielle Ålund née Podevin; Anna Qvarnström; Simone Immler; Leonie Moyle; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; sperm biology; sexual selection; speciation; hybridization; cryptic female choice; fertility; Ficedula flycatchers; Biologi med inriktning mot zooekologi; Biology with specialization in Animal Ecology;

   Sammanfattning : Sexual reproduction entails complex co-evolution between the sexes, necessary for successful fertilization, ensuring individual and population-level fitness. Interfertility is the main criterion for species definition and understanding speciation requires detailed studies of reproductive barriers. LÄS MER

5. 4. EXPOSURE TO PERSISTENT ORGANOCHLORINE POLLUTANTS AND MALE SEMEN FUNCTION

   Författare :Anna Rignell-Hydbom; Avdelningen för arbets- och miljömedicin; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Miljömedicin; Environmental health; epididymal and accessory sex gland function; Y:X sperm chromosome ratio; sperm chromation integrity; sperm concentration; sperm motility; persistent organochlorine poluutants;

   Sammanfattning : Persistent organochlorine pollutants (POPs), such as polychlorinated biphenyls (PCB) and the insecticide dichloro-diphenyl-dichloro-ethylene (DDT) have been released into the environment mainly since the second World War. POPs accumulate especially in highly ranked predators of the aquatic food chain. LÄS MER

7. 5. Same, same but different : lesbian couples undergoing sperm donation

   Författare :Catrin Borneskog; Agneta Skoog Svanberg; Gunilla Sydsjö; Claudia Lampic; Johanne Sundby; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Lesbian couples; sperm donation; assisted reproduction; relationship quality; symptoms of anxiety and depression; parenting stress; Obstetrik och gynekologi; Obstetrics and Gynaecology;

   Sammanfattning : Introduction: The desire to have children and form a family is for many people central for life fulfilment and the desire does not differ by sexual orientation. Due a series of societal changes during the last decade, today we see a lesbian baby boom. LÄS MER