Sökning: "spike"

Visar resultat 1 - 5 av 106 avhandlingar innehållade ordet spike.

1. 1. Speciation analysis of butyl- and phenyltin compounds in environmental samples by GC separation and atomic spectrometric detection

   Författare :Dong Nguyen Van; Wolfgang Frech; Anders Cedergren; Erwin Rosenberg; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Organotin speciation analysis; species-specific isotope dilution; inductively coupled plasma mass spectrometry; single isotope spike; multi-isotope spike; redistribution; species transformation; preparative liquid chromatography; gas chromatography; line source atomic absorption spectrometry; continuum source atomic absorption spectrometry; Analytical chemistry; Analytisk kemi;

   Sammanfattning : The main goal of the work presented in this thesis is to improve the reliability of existing methods for speciation analysis of organotin compounds Species-specific isotope dilution (SSID) calibration in combination with gas chromatography – inductively coupled plasma mass spectrometry was used to investigate the transformation of phenyltin species during sample preparation. Isotope-enriched phenyltin species were synthesized from corresponding isotope-enriched tin metals. LÄS MER

3. 2. Oscillations and spike statistics in biophysical attractor networks

   Författare :Mikael Lundqvist; Anders Lansner; Arvind Kumar; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Attractor networks; computational neuroscience; cortex; datalogi; Computer Science;

   Sammanfattning : The work of this thesis concerns how cortical memories are stored and retrieved. In particular, large-scale simulations are used to investigate the extent to which associative attractor theory is compliant with known physiology and in vivo dynamics. LÄS MER

4. 3. Activation of the spike proteins of alpha- and retroviruses

   Författare :Shang-Rung Wu; Karolinska Institutet; Karolinska Institutet; []
   Nyckelord :Alphavirus; Retrovirus; Fusion protein; electron cryomicroscopy; intermediate structure;

   Sammanfattning : Enveloped viruses like human immunodeficiency virus type 1 (HIV-1) enter cells by fusing their membrane with that of the cell plasma membrane, while others, like influenzavirus and alphavirus enter via uptake into endosomes and fusion with the endosomal membrane. For this they carry spike proteins. LÄS MER

5. 4. Spike-Based Bayesian-Hebbian Learning in Cortical and Subcortical Microcircuits

   Författare :Philip Tully; Anders Lansner; Matthias Hennig; Gordon Pipa; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Bayes rule; synaptic plasticity and memory modeling; intrinsic excitability; naïve Bayes classifier; spiking neural networks; Hebbian learning; neuromorphic engineering; reinforcement learning; temporal sequence learning; attractor network; Computer Science; Datalogi;

   Sammanfattning : Cortical and subcortical microcircuits are continuously modified throughout life. Despite ongoing changes these networks stubbornly maintain their functions, which persist although destabilizing synaptic and nonsynaptic mechanisms should ostensibly propel them towards runaway excitation or quiescence. LÄS MER

7. 5. In silico protein design for the enhancement of protein stability and function

   Författare :David A. Hueting; Per-Olof Syrén; Hjalmar Brismar; Zbynek Prokop; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Protein Engineering; Ancestral sequence reconstruction; terpene cyclases; SARS-CoV-2; Spike protein; PET; PETase; rational engineering; Proteinteknik; Förfäders sekvensrekonstruktion; Terpencyklas; SARS-CoV-2; Spike protein; PET; PETas; rationell proteinteknik; Kemi; Chemistry;

   Sammanfattning : Enzymes are natures catalysts that increase the rate of a chemical reaction. The increased rate of a reaction is required to be able to sustain life. Despite the huge impact of enzymes, they are not perfect catalysts. LÄS MER