Development of Q-band EPR/ENDOR spectrometer and EPR/ENDOR studies of dinitrosyl iron model complexes

A robust yet sensitive Q-band (35 GHz) cavity has been designed for routine variable temperature EPR (electron paramagnetic resonance) and ENDOR (electron nuclear double resonance) measurements down to 2 K. It consists of an aluminum or brass (plain, silver or gold plated) ribbon imbedded in a cylindrical epoxy or epoxy/quartz composite with a tunable piston at the bottom. The cavity has all the advantages of the traditional silver wire-wound cavity often used for Q-band measurements but is much more robust and easier to construct. The cavity suppresses degenerate resonant modes and minimizes wall eddy currents induced by field modulation. With standard Varian Q-band modulation coils, a 100-kHz modulation field of 27 G peak-to-peak is obtained at the sample. The cavity Q\rm\sb{L} ($\approx$2500) and weak pitch signal/noise ($\approx$1000:1) with a Varian/E-110 microwave bridge are comparable to those obtained with either a traditional wire-wound cavity or a cavity constructed with a thin silver wall on an epoxy/quartz substrate. A set of parallel posts along the axis of the cavity (bidirection) form the ENDOR coil. Dinitrosyl iron model complexes with ligands of cysteine, mercaptoethanol, thioglycolic acid, ethanethiol, penicillamine and imidazole were studied by EPR and ENDOR spectroscopy. X-band and Q-band ENDOR measurements have been made at various fields across the EPR envelope at temperatures from 2 K to 100 K. We have assigned most of the \sp1H resonances with reasonable certainty. The data confirm the thiol groups binding in the complexes with mercaptan ligands at room temperatures, and suggest that a structural rearrangement occurs with dinitrosyl iron cysteine and penicillamine upon freezing the sample, in which case coordination of both the thiol and amino group takes place. The assignment of axial EPR spectra to thiol coordination in every instance has also been cast in doubt by our data

ANALYSIS OF THE JOINT ANGULES OF THE THROWING ARM IN JAVELIN THROW

The purpose of this study was to explore the feasibility of using the panning method to analyze the joint angles of the throwing arm during the throwing of javelin. Two cameras (250 Hz) were set on the side and the back of the runway to analyze the athlete’s throwing arm movemen with a panning method. Besides the joint angles of the shoulder (horizontal abduction/ horizontal adduction, abduction/ adduction, internal rotation/external rotation) and the elbow (extension/ flexion), the pronation/supination angles of the forearm, the ulnar/ radial flexion and the palmar flexion/ dorsiflexion of the wrist were also calculated . For each angle of the joints of the same trail of an athlete, the ICC (Intravlass correlation coefficients) of the two results from two different analysisers was bigger than 0.95 (

Fidelity of a Bose-Einstein Condensate

We investigate fidelity, the Loschmidt echo, for a Bose-Einstein Condensate. It is found that the fidelity decays with time in various ways (exponential, Gaussian, and power-law), depending on the choice of initial coherent state as well as the parameters that determine properties of the underlying classical dynamics. Moreover, high fidelity is found for initial states lying in the regular region of a mixed-type phase space. A possible experimental scheme is suggested.Comment: 5 pages and 6 figure

Innovations in bioreactor operational modes – Hybrid semi-continuous processes to push beyond the limits of conventional fed-batch cultures

Due to the limits of feed volume addition and the problem of amino acid counter ion, miscellaneous osmolyte, and cell growth inhibitor accumulation, the fed-batch mode of bioreactor operation for CHO cell production of protein therapeutics is inherently limited with respect to the cell densities and productivities that are achievable. Continuous or perfusion culture with cell retention can overcome some of these limitations, but suffers from the disadvantages of large volume media consumption, long times to reach peak cell densities, and complications with cell retention devices. We will describe hybrid versions of continuous culture that overcome many of these limitations and utilize a unique and simple technology which allows cells to control their own rate of perfusion with continuous feedback. Volumetric productivities of greater than 1 gram/L/day (more than double the optimized fed-batch culture) for several moderate specific productivity cell lines have been achieved with very modest medium volumes, comparatively simple bioreactor operations, and a batch length that fits in a standard fed-batch window. Methods of operation and experimental results obtained at the pilot scale when coordinating these hybrid continuous cultures with a continuous downstream process will also be discussed

Cell-controlled high-intensity perfusion and hybrid fed-batch systems that drastically reduce perfusion rates and harmonize with continuous downstream processing

Peak cell densities in fed-batch cultures of mammalian cells can be limited by the depletion of nutrients or accumulation of inhibitors. Since addition of nutrients is relatively straight forward, inevitably it is growth inhibitor buildup, combined with the practical limits of feed volume addition and the problem of amino acid counter ion and miscellaneous osmolyte accumulation, that serve to limit productivity in the industry standard fed-batch bioreactor. To break these barriers we have begun to investigate mixed modes of bioreactor operation, some using novel methods for cell-controlled perfusion, which can substantially reduce the volumes of perfusion medium required, suppress lactic acid formation, shorten the time to reach peak cell densities, and reduce the complications associated with cell retention devices. Our methods of high-intensity perfusion and mixed mode bioreactor operation are also more compatible with the move to continuous downstream processing as the stream delivered is more concentrated and provides a more continuous daily mass of product to allow for reduced affinity chromatography scale. The techniques we will describe significantly increase viable cell densities and have achieved volumetric productivities of 1.0-1.5 grams/L/day (nearly 4X the optimized fed-batch culture in one case) for several moderate specific productivity cell lines, while using very modest medium volumes, highly concentrated perfusion media, comparatively simple bioreactor operations, and a batch length that fits in a standard fed-batch window. Methods of operation and experimental results obtained at the pilot (100 liter) scale when coordinating these hybrid continuous cultures with a continuous downstream process will also be discussed

Who's Watching Me?: Exploring the Impact of Audience Familiarity on Player Performance, Experience, and Exertion in Virtual Reality Exergames

Familiarity with audiences plays a significant role in shaping individual performance and experience across various activities in everyday life. This study delves into the impact of familiarity with non-playable character (NPC) audiences on player performance and experience in virtual reality (VR) exergames. By manipulating of NPC appearance (face and body shape) and voice familiarity, we explored their effect on game performance, experience, and exertion. The findings reveal that familiar NPC audiences have a positive impact on performance, creating a more enjoyable gaming experience, and leading players to perceive less exertion. Moreover, individuals with higher levels of self-consciousness exhibit heightened sensitivity to the familiarity with NPC audiences. Our results shed light on the role of familiar NPC audiences in enhancing player experiences and provide insights for designing more engaging and personalized VR exergame environments.Comment: 10 pages, 5 figures, IEEE International Symposium on Mixed and Augmented Reality (ISMAR) 202