George R Welch

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2 SUMMARY We provide a critical survey of some of the major limitations of the principles and applications of metabolic control analysis, with special reference to the enhancement of fluxes of biotechnological interest. Experimental methods of single-cell analysis such as flow cytometry show that the implicit assumption that we study and model ensembles of(More)
Flow cytometric assays of viable boar sperm were developed to measure reactive oxygen species (ROS) formation (oxidization of hydroethidine to ethidium), membrane lipid peroxidation (oxidation of lipophilic probe C(11)-BODIPY(581/591)), and mitochondrial inner transmembrane potential (DeltaPsi(m); aggregation of mitochondrial probe JC-1) during hypothermic(More)
Nanoscale real-time molecular sensing requires large signal enhancement, small background, short detection time and high spectral resolution. We demonstrate a new vibrational spectroscopic technique which satisfies all of these conditions. This time-resolved surface-enhanced coherent anti-Stokes Raman scattering (tr-SECARS) spectroscopy is used to detect(More)
We show that the effective decay rate of Zeeman coherence, generated in a 87 Rb vapor by linearly polarized laser light, increases significantly with the atomic density. We explain this phenomenon as the result of radiation trapping. Our study shows that radiation trapping must be taken into account to fully understand many electromagnetically induced(More)
Effects of hypothermic storage on intracellular calcium, reactive oxygen species formation, mitochondrial function, motility, and plasma membrane integrity in striped bass (Morone saxatilis) sperm Abstract Experiments were conducted to determine the effect of hypothermic 24 h storage on striped bass sperm cell plasma membrane integrity, free intracellular(More)
A highly excited hydrogen atom in a strong magnetic field, the so-called "diamagnetic hydrogen atom," is among the simplest nonseparable systems in quantum mechanics. Understanding it can provide a key to the more general aspects of nonseparable systems. The problem is also attracting attention in the context of nonlinear dynamics because its classical(More)
Cavity quantum electrodynamics-the study of interactions of individual atoms with quantum fields in cavities-has grown into an active area of quantum optics. 2 A seminal experiment in this area was the inhibition of spontaneous emission of an excited atom, first demonstrated in our laboratory some years ago. 3 During this past year, we have completed a(More)
The objective was to determine the effects of osmolality on the energy status of testicular spermatozoa of striped bass incubated in a TRIS free base-NaCl medium (pH 8) adjusted to either 300 (T300) or 600 mOsm/kg (T600) with NaCl. High mitochondrial inner transmembrane potential (DeltaPsim) was assessed (flow cytometry) with the mitochondrial probe 5, 5',(More)
We report the observation of small group velocities of order 90 meters per second, and large group delays of greater than 0.26 ms, in an optically dense hot rubidium gas (≈ 360 K). Media of this kind yield strong nonlinear interactions between very weak optical fields, and very sharp spectral features. The result is in agreement with previous studies on(More)
Enhancing the spectral sensitivity of interferometers using slow-light media " , Opt. How to play with the spectral sensitivity of interferometers using slow light concepts and how to do it practically " , Third European Workshop on Ultraslow group velocity and enhanced nonlinear optical effects in a coherently driven hot atomic gas, " Phys. ABSTRACT: A(More)