Sökning: "djur historia"

Visar resultat 21 - 25 av 26 avhandlingar innehållade orden djur historia.

1. 21. On the Regulation of Ornithine Decarboxylase

   Författare :Eva Lövkvist Wallström; Institutionen för experimentell medicinsk vetenskap; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fysiologi; Physiology; Crithidia fasciculata.; polyamines; Ornithine decarboxylase; translational control; osmolarity; untranslated region; COS cells; CHO cells; transfection; protein turnover; PEST region;

   Sammanfattning : The polyamines putrescine, spermidine and spermine have been shown to be involved in cell growth and differentiation, and are considered to be crucial components of the living cell. The synthesis of polyamines in the cell is strictly regulated. LÄS MER

3. 22. Potential for B-physics measurements with a fixed-target proton-collision experiment

   Författare :Jenny Ivarsson; Partikel- och kärnfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Elementary particle physics; CP Violation; quantum field theory; Elementarpartikelfysik; HERA-B; Fixed Target; kvantfältteori; B Physics; Monte Carlo Simulations; Fysicumarkivet A:1999:Ivarsson;

   Sammanfattning : HERA-B is a high-energy physics experiment at HERA. It is a fixed-target experiment with a forward spectrometer to benefit from the strong boost of beauty hadrons. The main goal of HERA-B is to detect and measure the degree of CP violation in exclusive B-decays, with emphasis on the {em golden} decay, $golden$. LÄS MER

4. 23. Upper middle Cambrian through Furongian of Scandinavia with focus on trilobites, paleoenvironments and correlations

   Författare :Fredrik Terfelt; Berggrundsgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Paleontologi; Palaeontology; Scandinavia; Paleoenvironments; Biostratigraphy; Trilobites; Cambrian; Furongian;

   Sammanfattning : This thesis is based on studies of upper middle Cambrian through Furongian strata in Scandinavia with focus on trilobite biostratigraphy, taxonomy, paleoecology, and intercontinental correlation. The material studied derives mainly from Västergötland and Scania, southern Sweden. LÄS MER

5. 24. Plant colonization of oak plantations - the interactive effects of local environment and land-use history

   Författare :Karin Valtinat; Biologiska institutionen; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nitrogen mineralization; Phosphorus; Plant ecology; Växtekologi; Soil acidity; Seed sowing; Dispersal limitation; Species diversity; Indicator species analysis; Functional groups; Succession; Understory vegetation; Land-use history; Temperate forest;

   Sammanfattning : In Europe, only small fragments of deciduous woodlands remain intact and species dependent on this ecosystem have declined. In southern Sweden, a shifting trend during the 20th century, with more afforestations on former arable land, resulted in new oak stands. These new stand are either on former arable fields or on continuously forested land. LÄS MER

7. 25. Conodont biostratigraphy, taxonomy and palaeoecology in the Darriwilian (Middle Ordovician) of Baltoscandia - with focus on meteorite and extraterrestrial chromite-rich strata

   Författare :Johanna Mellgren; Berggrundsgeologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Conodonts; biostratigraphy; taxonomy; palaeoecology; morphometrics; extraterrestrial chromite; meteorites; Darriwilian; Middle Ordovician; Baltoscandia;

   Sammanfattning : This thesis deals with conodont biostratigraphy and palaeoecology in the Darriwilian (Middle Ordovician) of Baltoscandia, with focus on limestone strata showing traces of the ~ 470 Ma L-chondrite parent body break-up. The evidence for this cosmic event includes abundant centimeter to decimeter-sized fossil meteorites and elevated levels of sediment-dispersed extraterrestrial L-type chromite found in a stratigraphical interval corresponding to the uppermost Lenodus antivariabilis, the L. LÄS MER