Sökning: "geographical origin"

Visar resultat 1 - 5 av 81 avhandlingar innehållade orden geographical origin.

1. 1. Evolution of asexuality in insects : Polyploidy, hybridization and geographical parthenogenesis

   Författare :Magnus Lundmark; Anssi Saura; Anders Nilsson; Davis Parker; Umeå universitet; []
   Nyckelord :Molecular genetics; weevils; geographical parthenogenesis; hybridization; polyploidy; Genetik; Otiorhynchus; Genetics; genetik;

   Sammanfattning : Asexual reproduction and polyploidy are relatively rare in animals with chromosomal sex determination and always represent a derived condition. To accomplish asexual reproduction several changes in gene expression are required in the mechanism of oogenesis. LÄS MER

3. 2. Ethnic heterogeneity of the North-Swedish population : its origin and medical consequences

   Författare :Per-Olof Nylander; Umeå universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Ethnic heterogeneity; Northern Sweden; Population genetics; Finns; Saamis; Genetic markers; Hypercholesterolemia;

   Sammanfattning : Northern Sweden shows a unique population structure with remarkable geographical variations in the distribution of genetic disorders as well as genetic markers like blood groups, serum groups and red cell enzyme types. The present-day population of northern Sweden is a mixture of people of Finnish, Saamish (Lappish) and Central-Swedish origin. LÄS MER

4. 3. Immunoglobulin Gene Analysis in Different B cell Lymphomas : With Focus on Cellular Origin and Antigen Selection

   Författare :Mia Thorsélius; Richard Rosenquist Brandell; Christer Sundström; Anders Rosén; Uppsala universitet; []
   Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Genetics; B cell lymphoma; Immunoglobulin; V gene; somatic hypermutation; antigen selection; quantitative PCR; Genetik; Clinical genetics; Klinisk genetik;

   Sammanfattning : B cell lymphoma (BCL) comprises a biologically and clinically heterogeneous group of tumors deriving from different stages of B cell development. The immunoglobulin (Ig) variable heavy chain (VH) gene rearrangement is unique for each BCL and can be used to reveal cellular origin, to study signs of antigen selection and to quantify tumor cell load. LÄS MER

5. 4. Essays on intergenerational income mobility, geographical mobility, and education

   Författare :Stefanie Heidrich; Thomas Aronsson; David Granlund; Magnus Wikström; Markus Jäntti; Umeå universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; optimal taxation; social norms; intergenerational mobility; regional analysis; multilevel model; child human capital development; moving costs; simulation of income paths; lifetime income; nationalekonomi; Economics;

   Sammanfattning : This thesis consists of an introductory part and the following four self-contained papers:In Paper [I] we analyze the implications of social identity and self-categorization for optimal redistributive income taxation. A two-type model is supplemented by an assumption that individuals select themselves into social categories, in which norms are formed and education effort choices partly depend on these norms. LÄS MER

7. 5. Features and Origin of Electromagnetic Fields Generated by Lightning Flashes

   Författare :Mohd Muzafar Ismail; Vernon Cooray; Farhad Rachidi; Uppsala universitet; []
   Nyckelord :negative cloud-to-ground lightning flashes; HF and VHF radiation; chaotic pulse trains; lightning initiation; zero-crossing time; electromagnetic fields; Engineering Science with specialization in Atmospheric Discharges; Teknisk fysik med inriktning mot atmosfäriska urladdningar;

   Sammanfattning : Negative cloud-to-ground (CG) lightning flashes transport negative charge from cloud to ground. Negative ground flashes typically involve various processes identified as preliminary breakdown, stepped leader, return stroke, dart leader, dart-stepped leader, subsequent return stroke, and cloud activity between strokes, such as regular pulse trains and chaotic pulse trains. LÄS MER