Determination of molecular spectroscopic parameters and energy-transfer rates by double-resonance spectroscopy

The spectroscopy of small to medium-size polyatomic molecules can be extremely complex, especially in higher-lying overtone and combination vibrational levels. The high density of levels also complicates the understanding of inelastic collision processes, which is required to model energy transfer and collision broadening of spectral lines. Both of these problems can be addressed by double-resonance spectroscopy, i.e., time-resolved pump-probe measurements using microwave, infrared, near-infrared, and visible-wavelength sources. Information on excited-state spectroscopy, transition moments, inelastic energy transfer rates and propensity rules, and pressure-broadening parameters may be obtained from such experiments. Examples are given for several species of importance in planetary atmospheres, including ozone, silane, ethane, and ammonia

Comparison of conventional Lagrangian stochastic footprint models against LES driven footprint estimates

In this study we introduce a comparison method for footprint model results by evaluating the performance of conventional Lagrangian stochastic (LS) footprint models that use parameterised flow field characteristics with results of a Lagrangian trajectory model embedded in a large eddy simulation (LES) framework. The two conventional models follow the particles backward and forward in time while the trajectories in LES only evolve forward in time. We assess their performance in two unstably stratified boundary layers at observation levels covering the whole depth of the atmospheric boundary layer. We present a concept for footprint model comparison that can be applied for 2-D footprints and demonstrate that comparison of only cross wind integrated footprints is not sufficient for purposes facilitating two dimensional footprint information. Because the flow field description among the three models is most realistic in LES we use those results as the reference in the comparison. We found that the agreement of the two conventional models against the LES is generally better for intermediate measurement heights and for the more unstable case, whereas the two conventional flux footprint models agree best under less unstable conditions. The model comparison in 2-D was found quite sensitive to the grid resolution

Anti-microbial Use in Animals: How to Assess the Trade-offs

Antimicrobials are widely used in preventive and curative medicine in animals. Benefits from curative use are clear – it allows sick animals to be healthy with a gain in human welfare. The case for preventive use of antimicrobials is less clear cut with debates on the value of antimicrobials as growth promoters in the intensive livestock industries. The possible benefits from the use of antimicrobials need to be balanced against their cost and the increased risk of emergence of resistance due to their use in animals. The study examines the importance of animals in society and how the role and management of animals is changing including the use of antimicrobials. It proposes an economic framework to assess the trade-offs of anti-microbial use and examines the current level of data collection and analysis of these trade-offs. An exploratory review identifies a number of weaknesses. Rarely are we consistent in the frameworks applied to the economic assessment anti-microbial use in animals, which may well be due to gaps in data or the prejudices of the analysts. There is a need for more careful data collection that would allow information on (i) which species and production systems antimicrobials are used in, (ii) what active substance of antimicrobials and the application method and (iii) what dosage rates. The species need to include companion animals as well as the farmed animals as it is still not known how important direct versus indirect spread of resistance to humans is. In addition, research is needed on pricing antimicrobials used in animals to ensure that prices reflect production and marketing costs, the fixed costs of anti-microbial development and the externalities of resistance emergence. Overall, much work is needed to provide greater guidance to policy, and such work should be informed by rigorous data collection and analysis systems

Guidelines for initiation of anti-tumour necrosis factor therapy in rheumatoid arthritis: similarities and differences across Europe.

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Simulation results for a low energy nuclear recoil yields measurement in liquid xenon using the MiX detector

Measuring the scintillation and ionization yields of liquid xenon in response to ultra-low energy nuclear recoil events is necessary to increase the sensitivity of liquid xenon experiments to light dark matter. Neutron capture on xenon can be used to produce nuclear recoil events with energies below $0.3$ keV$_\text{NR}$ via the asymmetric emission of $\gamma$ rays during nuclear de-excitation. The feasibility of an ultra-low energy nuclear recoil measurement using neutron capture was investigated for the Michigan Xenon (MiX) detector, a small dual-phase xenon time projection chamber that is optimized for a high scintillation gain. Simulations of the MiX detector, a partial neutron moderator, and a pulsed neutron generator indicate that a population of neutron capture events can be isolated from neutron scattering events. Further, the rate of neutron captures in the MiX detector was optimized by varying the thickness of the partial neutron moderator, neutron pulse width, and neutron pulse frequency.Comment: 7 pages, 5 figures. LIDINE 2022 proceeding

A Low Cost Thermal Control Method for Testing in a Mars Environment

Due to the unique thermal vacuum testing requirements for a Mars Rover instrument, NASA Goddard developed a low cost, high fidelity thermal control system utilizing Thermal Electric Coolers (TECs) combined with a heat rejection fluid loop to actively control 8 independent payload thermal boundary zones in a simulated Mars pressure vacuum chamber with a Carbon Dioxide atmosphere. These zones could control instrument components to a specific temperature as a function of time to simulate exact temporal flight boundary predictions.The Mars Organic Molecule Analyzer (MOMA) instrument is a dual source (pyrolysis gas chromatograph and laser desorption) mass spectrometer (MS) based package that detects and characterizes organic molecules, as part of ESA's 2020 ExoMars Rover mission to seek the signs of life on Mars.Due to the unique thermal vacuum testing requirements for a Mars Rover instrument, NASA Goddard developed a low cost, high fidelity thermal control system utilizing Thermal Electric Coolers (TECs) combined with a heat rejection fluid loop to actively control 8 independent payload thermal boundary zones in a simulated Mars pressure vacuum chamber with a Carbon Dioxide atmosphere. These zones could control instrument components to a specific temperature as a function of time to simulate exact temporal flight boundary predictions.The Mars Organic Molecule Analyzer (MOMA) instrument is a dual source (pyrolysis gas chromatograph and laser desorption) mass spectrometer (MS) based package that detects and characterizes organic molecules, as part of ESA's 2020 ExoMars Rover mission to seek the signs of life on Mars

Structure of sulfamidase provides insight into the molecular pathology of mucopolysaccharidosis IIIA

Mucopolysaccharidosis type IIIA (Sanfilippo A syndrome), a fatal childhood-onset neurodegenerative disease with mild facial, visceral and skeletal abnormalities, is caused by an inherited deficiency of the enzyme N-sulfoglucosamine sulfohydrolase (SGSH; sulfamidase). More than 100 mutations in the SGSH gene have been found to reduce or eliminate its enzymatic activity. However, the molecular understanding of the effect of these mutations has been confined by a lack of structural data for this enzyme. Here, the crystal structure of glycosylated SGSH is presented at 2Å resolution. Despite the low sequence identity between this unique N-sulfatase and the group of O-sulfatases, they share a similar overall fold and active-site architecture, including a catalytic formylglycine, a divalent metal-binding site and a sulfate-binding site. However, a highly conserved lysine in O-sulfatases is replaced in SGSH by an arginine (Arg282) that is positioned to bind the N-linked sulfate substrate. The structure also provides insight into the diverse effects of pathogenic mutations on SGSH function in mucopolysaccharidosis type IIIA and convincing evidence for the molecular consequences of many missense mutations. Further, the molecular characterization of SGSH mutations will lay the groundwork for the development of structure-based drug design for this devastating neurodegenerative disorder. © 2014 International Union of Crystallography.This work was funded by the DFG. Partial support from DFG grant No. SH 14/5-1 is gratefully acknowledged (NSS). IU is grateful to the Spanish MEC and Generalitat de Catalunya for financial support (grants BFU2012-35367, IDC-20101173 and 2009SGR-1036)Peer Reviewe

Roles for a Lipid Phosphatase in the Activation of its Opposing Lipid Kinase

Fig4 is a phosphoinositide phosphatase that converts PI3,5P2 to PI3P. Paradoxically, mutation of Fig4 results in lower PI3,5P2, indicating that Fig4 is also required for PI3,5P2 production. Fig4 promotes elevation of PI3,5P2, in part, through stabilization of a protein complex that includes its opposing lipid kinase, Fab1, and the scaffold protein Vac14. Here we show that multiple regions of Fig4 contribute to its roles in the elevation of PI3,5P2: Its catalytic site, an N-terminal disease-related surface, and a C-terminal region. We show that mutation of the Fig4 catalytic site enhances the formation of the Fab1-Vac14-Fig4 complex, and reduces the ability to elevate PI3,5P2. This suggests that independent of its lipid phosphatase function, the active site plays a role in the Fab1-Vac14-Fig4 complex. We also show that the N-terminal disease-related surface contributes to the elevation of PI3,5P2 and promotes Fig4 association with Vac14 in a manner that requires the Fig4 C-terminus. We find that the Fig4 C-terminus alone interacts with Vac14 in vivo and retains some functions of full-length Fig4. Thus, a subset of Fig4 functions are independent of its phosphatase domain and at least three regions of Fig4 play roles in the function of the Fab1-Vac14-Fig4 complex