Sökning: "gradient"

Visar resultat 6 - 10 av 1260 avhandlingar innehållade ordet gradient.

1. 6. The Many Facets of bicoid Gradient Formation in Drosophila

   Författare :Xiaoli Cai; Stefan Baumgartners grupp Utvecklingsbiologi i invertebrater; []
   Nyckelord :Drosophila; bicoid; gradient formation; ARTS model; cortical microtubule; drug;

   Sammanfattning : In Drosophila, the Bicoid protein servers as paradigm as the first identified morphogen, whose concentration gradient provides the initial positional information in the anterior half of the embryo. There, it differentially activates segmentation genes, in particular the gap genes. LÄS MER

3. 7. Computational Diffusion MRI: Optimal Gradient Encoding Schemes

   Författare :Mohammad Alipoor; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Gradient Encoding Scheme; ADC imaging; Diffusion MRI; D-optimal experiment design; Diffusion Tensor Imaging; Optimal Image acquisition; Second and Fourth Order Tensors.; Diffusion Kurtosis Imaging;

   Sammanfattning : Diffusion-weighted magnetic resonance imaging (dMRI) is a non-invasivestructural imaging technique that provides information about tissue microstructures.Quantitative measures derived from dMRI reflect pathologicaland developmental changes in living tissues such as human brain. LÄS MER

4. 8. Capacitive Mixing for Extracting Concentration Gradient Energy

   Författare :Zhi Zou; Longcheng Liu; Chia-Hung Hou; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; capacitive mixing; salinity gradient energy; salt difference energy; electric double layer; flow electrode CapMix; kapacitiv blandning; salthaltsgradientenergi; saltskillnadsenergi; elektriskt dubbelskikt; flödeselektrod CapMix.; Chemical Engineering; Kemiteknik;

   Sammanfattning : Capacitive mixing (CapMix) is a renewable method of extracting energy from the salinity gradient energy (SGE) between seawater and freshwater. The classical CapMix systems using solid electrodes generate electricity by periodically circulating seawater and freshwater into the CapMix system. LÄS MER

5. 9. Ecological and Evolutionary Consequences of Herbivory in the Perennial Herb Lythrum salicaria

   Författare :Lina Lehndal; Jon Ågren; Peter Hambäck; Marc Johnson; Uppsala universitet; []
   Nyckelord :Disturbance gradient; Female reproductive success; Galerucella calmariensis; Galerucella pusilla; Herbivore removal; Latitudinal gradient; Local adaptation; Nanophyes marmoratus; Plant-herbivore interactions; Plant size; Resistance to herbivory; Tolerance to damage; Biology with specialization in Ecological Botany; Biologi med inriktning mot ekologisk botanik;

   Sammanfattning : In this thesis, I combined field, common-garden and greenhouse experiments to examine the ecological and evolutionary consequences of plant-herbivore interactions in the perennial herb Lythrum salicaria. More specifically I examined (1) whether resistance and tolerance to damage from herbivores vary with latitude and are positively related to the intensity of herbivory in natural populations, (2) whether effects of herbivory on plant fitness vary with latitude, (3) whether populations are locally adapted and whether herbivory influences the relative fitness of populations, and (4) whether the intensity and effects of insect herbivory on reproductive output vary locally along a disturbance gradient and are associated with differences in plant resistance. LÄS MER

7. 10. Formations and Obstacle Avoidance in Mobile Robot Control

   Författare :Petter Ögren; KTH; []
   Nyckelord :Mobile Robots; Robot Control; Obstacle Avoidance; Multi-robot system; Formation Control; Navigation Function; Lyapunov Function; Model Predictive Control; Receding Horizon Control; Gradient Climbing; Gradient Estimation.;

   Sammanfattning : This thesis consists of four independent papers concerningthe control of mobile robots in the context of obstacleavoidance and formation keeping. The first paper describes a new theoreticallyv erifiableapproach to obstacle avoidance. LÄS MER