Visar resultat 1 - 5 av 446 avhandlingar innehållade ordet oscillations.
Sammanfattning : Oscillations in the concentration of yeast glycolytic intermediates have been intensively studied since the 1950s, but these studies have so far been limited to observations of average oscillatory behavior in synchronized cultures. Hence, it has remained unknown whether the onset of oscillations is a collective property of the population which requires a high cell density, or if individual cells can oscillate also in isolation. LÄS MER
Sammanfattning : In this thesis I present different types of manipulations of microwave fields using tunable superconducting resonators. A resonator is made tunable by adding one or more superconducting quantum interference devices, SQUIDs. The SQUID consists of a superconducting loop with two Josephson junctions and acts as a tunable nonlinear inductor. LÄS MER
Sammanfattning : The complex set of reactions in metabolism has been extensively studied in populations with millions of cells, but much information can still be gained by studying the heterogeneous metabolic behaviour in individual cells. The first part of energy metabolism is called glycolysis and is very similar in mammalian cells, such as human cells, and in yeast cells. LÄS MER
4. On the Generation of cAMP Oscillations and Regulation of the Ca2+ Store-operated Pathway in Pancreatic Islet α- and β-cells
Sammanfattning : Insulin and glucagon are released in pulses from pancreatic β- and α-cells, respectively. Both cell types are electrically excitable, and elevation of the cytoplasmic Ca2+ concentration ([Ca2+]i) due to depolarization with voltage-dependent entry of the cation is the main trigger of hormone secretion. LÄS MER
Sammanfattning : Theta activity is one of the most prominent rhythms in the brain and appears to be conserved among mammals. These 4-12 Hz oscillations have been predominantly studied in the dorsal hippocampus where they are correlated with a broad range of voluntary and exploratory behaviors. LÄS MER