Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 20 of 22 for “"Chemical signal"”.
-
Development of light actuated chemical delivery platform on a 2-D array of micropore structure
<p>Localized chemical delivery plays an essential role in the fundamental information transfers within biological systems. Thus, the ability to mimic the natural chemical signal modulation would provide significant contributions to understand the functional signaling pathway of biological cells and …
-
Microwave chemical sensing using overmoded T-line designs and impact of real-time digitizer in the system
… resolution features that are specific to a given chemical. Very sharp lines which correspond to quantum states of the chemical allow for unique identification of the chemical. Recent advances have shown the possibility of room temperature microwave spectroscopy analysis in which the data is …
-
Studying the Competence Regulon Quorum Sensing Circuity in Streptococcus mitis
… communication. QS bacteria generate and release chemical signal molecules known as autoinducers, which increase in concentration as cell density increases. To determine the cell density and initiate the group behaviors such as virulence factor production, biofilm formation, and competence …
-
Study of cell-cell communication using 3D living cell microarrays
… by the emission and detection of a small chemical signal, an acyl-homoserine lactone. Through synthetic biology, I have engineered plasmids which express "sending" and "receiving" genes. Bacteria containing these plasmids were formed into complex 3D patterns, designed to assay signaling …
-
Approaches Towards the Synthesis of Bradyoxetin
Quorum sensing bacteria produce and release chemical signal molecules (like N-acyl homoserine lactones, AHL) that increase in concentration as a function of cell density. The responses cover a large spectrum of process such as the virulence in Staphylococcus aureus, competence for DNA-uptake in …
-
Waterhole Dynamics and Chemical Signals of African Elephants (<i> Loxodonta Africana </i>)
… communication in elephants, often via chemical signals. This study also determined behaviorally via biological assays (June 2006-June 2007) whether four known insect pheromones identified in the ovulatory urine of African elephants serve as sex-specific pheromones. When tested singly, …
-
Electrochemical and Magnetochemical Approaches for Neuronal Modulation
The development of tools to deliver chemical signals to specific neurons can enhance our understanding of chemical signaling in the nervous system and enable chemical therapies for neurological disorders. Existing technologies for chemical neuromodulation, including intracranial injection of …
-
Gene switches and their applications in eukaryotic systems
… way to regulate target genes using an external signal. By combining DNA binding domain, ligand binding domain, and activation domain, chimeric gene switches can be engineered to turn on or off a user-defined target gene or set of genes, in response to a user-defined chemical signal. In this …
-
Investigating Rhizobium Leguminosarum Metabolism and Rhizosphere Colonization Using High-Throughput Genomics and Erythritol Enrichments
… The results suggest that erythritol may act as a chemical signal that triggers a specialized response in R. leguminosarum 3841 to out-compete other soil bacteria in colonizing the rhizosphere, thereby nodulating legume roots. Overall, these results provide direction for developing inoculant …
-
Calcium dynamics in dendrites and spines of spiny neurons in the somatosensory ‘barrel’ cortex of the rat
… tested, representing a global intracellular chemical signal about the activity of the cell. In contrast, synaptically evoked excitatory postsynaptic potentials (EPSPs) resulted in a synapse specific, local increase in Ca2+. Pairing both stimuli at different inter-stimulus intervals revealed a …
-
Activation processes in biology
… including (but not limited to) the rates of chemical reactions, the unfolding of proteins, the nucleation of bubbles, and the condensation of gases. To understand the kinetics of these processes, we have to be able to calculate the rate of escape. In this thesis, I solve several of such of …
-
Molecular and biochemical characterization of steroid sulfotransferases from Brassica napus and Arabidopsis thaliana
… BNST genes are inducible by salicylic acid, a signal molecule in the defense response, suggesting that plants respond to pathogen infection by modulating steroid-dependent growth and developmental processes. BNST genes along with alcohol dehydrogenase ( ADH ) and xyloglucan …
-
Making Scents of Butterfly Pheromone Evolution
Insect chemical profiles are diverse and complex, reflecting the wide range of functions they serve. Volatile compounds are used in foraging, defence, and mating, and pheromones are particularly important to the lives of insects. These are chemical signals that mediate the behaviour of …
-
Taphonomy of pigmentary colours in fossil insects
… are overprinted by a strong pigment-specific signal. The trace element chemistry in fossil insects is controlled by both taxonomy and depositional context, indicating some diagenetic overprinting. Regions of the fossilized cuticles displaying different tones contain distinct suites of …
-
Inhibition of Monocyte Chemotaxis and Chemokine Macrophage Inflammatory Protein-1 Alpha, and Interleukin-8 Secretion by Lipopolysaccharide Isolated from Periodontal Pathogens
… system by secreting products that interfere with signals that promote chemotaxis of leukocytes enabling the pathogens to go unrestricted. When LPS binds to the Toll‑like receptor it promotes the secretion of proinflammatory cytokines in cells such as the macrophage, monocyte, and endothelial …
-
A Multi-level Mechanical Study of Hypocotyl Growth in the Dark
… The model also implied that a quantitative ‘chemical signal’ may exist and can be involved in the initiation of cell growth and thus the acropetal wave. For the next aim, an empirical model of hypocotyl cell growth was built based on data of cell sizes up to 72 hours post germination. Using …
-
Amino Acid Residues in LuxR Critical for its Mechanism of Transcriptional Activation during Quorum Sensing
… in <I>V. fischeri</I>, an acylated homoserine chemical signal (autoinducer) is synthesized by the bacteria and used to sense their own species in a given environment. As the autoinducer levels rise, complexes form between the autoinducer and the N-terminal domain of a regulatory protein, LuxR. …
-
Portable electrochemical and plasmonic biosensors for biomedical application
… smartwatchs or even headsets, can achieve signal generating and receiving by using interfaces like camera, flashlight, audio-jack, micro-USB and wireless module. On the other side, development in the micro-fluid system enables the integration of different diagnosis techniques like …
-
Age Effects on Social and Investigative Behaviors in a Closed Population of African Elephants
… male and female elephants during the entry to a signal-rich waterhole and in female African elephants across seasons. Chemosensory and social behaviors were recorded in Addo Elephant National Park between May 2004 and June 2005 using focal animal sampling. During the approach to a waterhole, …
Page 1 of 2