Search for dissertations about: "Per Erik Ahlberg"

Showing result 1 - 5 of 6 swedish dissertations containing the words Per Erik Ahlberg.

2. 1. The Origin of Tetrapod Limbs and Girdles: Fossil and Developmental Evidence

   Author : Catherine Anne Boisvert; Per Erik Ahlberg; Rolf Ohlsson; Johan Ledin; Lennart Olsson; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Organism biology; Organismbiologi;

   Abstract : Around 375 million years ago, the first tetrapods appeared, marking one of the most important events in vertebrate evolutionary history. The fin to limb transition saw the appearance of fingers and a weight bearing pelvic girdle. READ MORE

4. 2. Glycosaminoglycan Biosynthesis and Function in Zebrafish Development : Sugars Shaping Skeletons

   Author : Judith Habicher; Johan Ledin; Per Erik Ahlberg; Marion Kusche-Gullberg; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : Heparan sulfate (HS) and chondroitin/dermatan sulfate (CS/DS) proteoglycans are glycosylated proteins with important roles in animal development and homeostasis. HS and CS/DS are long, linear glycosaminoglycan (GAG) polysaccharides and attached to a core protein they form proteoglycans. READ MORE

5. 3. The role of the extracellular matrix in zebrafish cartilage development

   Author : Judith Habicher; Per Erik Ahlberg; Johan Ledin; Lwaki Ebarasi; Uppsala universitet; []
   Keywords : Biologi med inriktning mot zoologisk utvecklingsbiologi; Biology with specialization in Animal Development;

   Abstract : .... READ MORE

6. 4. Development and three-dimensional histology of vertebrate dermal fin spines

   Author : Anna Jerve; Per Erik Ahlberg; Martin Brazeau; Tatjana Haitina; Philippe Janvier; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; fin spine; paleontology; early vertebrate; histology; development; Biology with specialization in Evolutionary Organismal Biology; Biologi med inriktning mot evolutionär organismbiologi;

   Abstract : Jawed vertebrates (gnathostomes) consist of two clades with living representatives, the chondricthyans (cartilaginous fish including sharks, rays, and chimaeras) and the osteichthyans (bony fish and tetrapods), and two fossil groups, the "placoderms" and "acanthodians". These extinct forms were thought to be monophyletic, but are now considered to be paraphyletic partly due to the discovery of early chondrichthyans and osteichthyans with characters that had been previously used to define them. READ MORE

7. 5. Morphology, Taxonomy and Interrelationships of Tristichopterid Fishes (Sarcopterygii, Tetrapodomorpha)

   Author : Daniel Snitting; Per Erik Ahlberg; Graham Budd; Henning Blom; Zerina Johanson; Uppsala universitet; []
   Keywords : Organismic biology; Sarcopterygii; Tetrapodomorpha; Tristichopteridae; biogeography; phylogeny; Computed Tomography; Devonian; Organismbiologi;

   Abstract : Tristichopterids (Sarcopterygii, Tetrapodomorpha) form a monophyletic group of exclusively Devonian fishes. This thesis consists of descriptions of new material of tristichopterids and closely related taxa, as well as new interpretations and descriptions of previously figured material. READ MORE