The purpose of this study was to evaluate the impact sediment has on the survival of
bacteria in a typical rangeland stream. This information is an important component in
determining a time integrated prediction of bacterial numbers in the stream sediment and
overlying water. Bacterial survival in stream is a...
In this dissertation, my research work on excited state dynamics of small organic molecules in solutions is presented. Using femtosecond stimulated Raman spectroscopy (FSRS) as the main experimental tool, the excited state hydrogen-bonding dynamics (ESHBD) of Coumarin 102, a common laser dye molecule, in ethanol solution is examined with <150...
Intracellular pH (pH(i)) imaging is of paramount importance for life sciences. In this work, we implement the ultrafast electronic and stimulated Raman spectroscopies to unravel the fluorescence mechanism of an excitation-ratiometric pH(i) indicator in basic aqueous solution. After photoexcitation of the pH(i) indicator HPTS, a hidden charge-transfer (CT) state following...
This biological assessment (BA) documents the potential effects of existing Forest Service (FS) Land and Resource Management Plans (LRMPs), or 'Forest Plans' and Bureau of Land Management (BLM) Land Use Plans (LUPs) on the Canada Lynx (Lynx canadensis), hereafter referred to as the lynx. LRMPs and LUPs are collectively referred...
Ultrafast spectroscopy has recently gained momentum as a powerful, noninvasive characterization toolset capable of studying a diverse array of samples with applications in chemistry, physics, biology, engineering, and more. Two popular ultrafast spectroscopic techniques include femtosecond transient absorption (fs-TA) and femtosecond stimulated Raman spectroscopy (FSRS). The latter of these techniques...
In the past decades, femtosecond stimulated Raman spectroscopy (FSRS) has been gaining tremendous popularity in fundamental sciences stemming from chemistry to biology. It is capable of capturing both equilibrium and non-equilibrium structural information across a broad range of timescales with simultaneously high temporal and spectral resolutions. Femtosecond transient absorption spectroscopy...
Imaging Ca²⁺ dynamics in living systems holds great
potential to advance neuroscience and cellular biology. G-GECO1.1
is an intensiometric fluorescent protein Ca²⁺-biosensor with a Thr-Tyr-Gly chromophore. The protonated chromophore emits green
upon photoexcitation via excited-state proton transfer (ESPT). Upon
Ca²⁺ binding, a significant population of the chromophores becomes
deprotonated. It...
Lago Rupanco is located in the central plain of Chile
(Borgel, 1964) at 40° 50' S; 72° 30' W. It lies at 117 m
above sea level, and corresponds to type 28c of Hutchinson's
(1967) classification. Lago Rupanco is a warm, monomictic
lake, with winter circulation and summer stratification.
Physical,...
Ultrafast spectroscopy can exploit the structure-function relationship of chemical- and biological-based systems. More specifically, femtosecond stimulated Raman spectroscopy (FSRS) provides ground- and excited-state vibrational information with simultaneously high spectral (spatial) and temporal resolutions. The electronic counterpart, femtosecond transient absorption (fs-TA), complements FSRS data analysis as part of a comprehensive approach...
Fluorescent proteins (FPs) are luminescent biomolecules that emit characteristic hues upon irradiation. A group of calmodulin (CaM)-green FP (GFP) chimeras have been previously engineered to enable the optical detection of calcium ions (Ca²⁺). We investigate one of these genetically encoded Ca²⁺ biosensors for optical imaging (GECOs), GEM-GECO1, which fluoresces green...