Line-of-Sight Winds and Doppler Effect Smearing in ACE-FTS Solar Occultation Measurements

Line-of-sight wind profiles are derived from Doppler shifts in infrared solar occultation measurements from the Atmospheric Chemistry Experiment Fourier transform spectrometers (ACE-FTS), the primary instrument on SCISAT, a satellite-based mission for monitoring the Earth’s atmosphere. Comparisons suggest a possible eastward bias from 20 m/s to 30 m/s in ACE-FTS results above 80 km relative to some datasets but no persistent bias relative to other datasets. For instruments operating in a limb geometry, looking through a wide range of altitudes, smearing of the Doppler effect along the line of sight can impact the measured signal, particularly for saturated absorption lines. Implications of Doppler effect smearing are investigated for forward model calculations and volume mixing ratio retrievals. Effects are generally small enough to be safely ignored, except for molecules having a large overhang in their volume mixing ratio profile, such as carbon monoxide

A parallelized molecular collision cross section package with optimized accuracy and efficiency

Ion mobility-based separation prior to mass spectrometry has become an invaluable tool in the structural elucidation of gas-phase ions and in the characterization of complex mixtures. Application of ion mobility to structural studies requires an accurate methodology to bridge theoretical modelling of chemical structure with experimental determination of an ion's collision cross section (CCS). Herein, we present a refined methodology for calculating ion CCS using parallel computing architectures that makes use of atom specific parameters, which we have called MobCal-MPI. Tuning of ion-nitrogen van der Waals potentials on a diverse calibration set of 162 molecules returned a RMSE of 2.60% in CCS calculations of molecules containing the elements C, H, O, N, F, P, S, Cl, Br, and I. External validation of the ion-nitrogen potential was performed on an additional 50 compounds not present in the validation set, returning a RMSE of 2.31% for the CCSs of these compounds. Owing to the use of parameters from the MMFF94 forcefield, the calibration of the van der Waals potential can be extended to additional atoms defined in the MMFF94 forcefield (i.e., Li, Na, K, Si, Mg, Ca, Fe, Cu, Zn). We expect that the work presented here will serve as a foundation for facile determination of molecular CCSs, as MobCal-MPI boasts up to 64-fold speedups over traditional calculation packages.The authors would like to acknowledge the financial support provided by the Natural Sciences and Engineering Research Council (NSERC) of Canada

Ligand Specificity and Affinity in the Sulforhodamine B Binding RNA Aptamer

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.bbrc.2020.06.056. © 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Binding affinity and selectivity are critical properties of aptamers that must be optimized for any application. The sulforhodamine B binding RNA aptamer (SRB‐2) is a somewhat promiscuous aptamer that can bind ligands that vary markedly in shape, size and charge. Here we categorize potential ligands based on their binding mode and structural characteristics required for high affinity and selectivity. Several known and potential ligands of SRB‐2 were screened for binding affinity using LSPR, ITC and NMR spectroscopy. The study shows that rhodamine B has the ideal structural and electrostatic properties for selective and high‐affinity binding of the SRB‐2 aptamer.NSERC Discovery Grant 30345

Effect of Castration on Skeletal Muscle Protein Turnover and Muscle Enzyme Activities in Cattle

It is well established that proteins are continually synthesized and degraded in skeletal muscle, but the proteolytic enzymes involved in muscle protein degradation remain unknown. It is hypothesized that the calpain proteolytic system, which is known to be important in postmortem protein degradation and thus in meat tenderization, could also be involved in or even possibly initiate muscle protein degradation in the living animal. It is well documented that intact males grow more rapidly (15 to 17%), utilize feed more efficiently (10 to 13%) and produce higher yielding carcasses with less fat and more lean meat than castrates. However, the underlying mechanisms for these advantages have not been determined. The objective of this study was to determine the effect of gender (bull vs steer) on the relationship between muscle enzyme activity and muscle protein turnover in growing cattle

Meat Tenderness and the Calpain Enzyme System in Young Bulls and Steers

Comparisons of meat palatability between bulls and steers have indicated that meat from young bulls is more variable in tenderness. In addition, meat from bulls is usually numerically less tender, although the difference is frequently not statistically significant. This indicates that meat from bulls is only slightly, but consistently less tender than meat from steers. Numerous studies have attempted to link bull meat toughness to higher amounts and decreased solubility of connective tissue. However, it has been reported that this change in bull meat does not occur until 12 to 16 mo of age. It has been shown conclusively, using different species and a variety of conditions, that the calpain enzyme system (which occurs naturally in muscle) is responsible for a majority of the tenderization that occurs during aging of meat. The possible contribution of the calpain system to differences in postmortem tenderization of muscle from bulls and steers has not been reported. This study was conducted to examine the effect of castration on palatability traits and 24-hr postmortem activities of μ-calpain, m-calpain and calpastatin in loin muscle of cattle

Bridging Academia, Industry, and Culture

Alumni panel discussion at Georgia Tech's Digital Media Program - Yesterday and Today, a full day symposium, Monday, April 16, 2012, Technology Square Research Building (TSRB) AuditoriumRuntime: 40:18 minute

Line-of-Sight Winds and Doppler Effect Smearing in ACE-FTS Solar Occultation Measurements

Line-of-sight wind profiles are derived from Doppler shifts in infrared solar occultation measurements from the Atmospheric Chemistry Experiment Fourier transform spectrometers (ACE-FTS), the primary instrument on SCISAT, a satellite-based mission for monitoring the Earth’s atmosphere. Comparisons suggest a possible eastward bias from 20 m/s to 30 m/s in ACE-FTS results above 80 km relative to some datasets but no persistent bias relative to other datasets. For instruments operating in a limb geometry, looking through a wide range of altitudes, smearing of the Doppler effect along the line of sight can impact the measured signal, particularly for saturated absorption lines. Implications of Doppler effect smearing are investigated for forward model calculations and volume mixing ratio retrievals. Effects are generally small enough to be safely ignored, except for molecules having a large overhang in their volume mixing ratio profile, such as carbon monoxide

Stratospheric Aerosol Composition Observed by the Atmospheric Chemistry Experiment Following the 2019 Raikoke Eruption

Infrared aerosol spectra derived from Atmospheric Chemistry Experiment measurements following the June 2019 Raikoke volcanic eruption are used to evaluate the composition of stratospheric aerosols in the Arctic. A blanket of aerosols, spanning an altitude range from the tropopause (8–11 km) to 20 km, persisted in the stratosphere over northern latitudes for many months. The aerosols within this blanket were almost exclusively sulfates. The percentage of sulfuric acid in the aerosols decreased over time, dropping below 50% H2SO4 concentration at some altitudes by March 2020. Contrary to previous reports, the aerosol blanket was not comprised of smoke particles

Veritas & Vanitas: A Journal of Creative Nonfiction

A journal of creative nonfiction produced by students at the Marion campus of The Ohio State University with contributions from the students and faculty at the Marion campus of The Ohio State University and Marion Technical College