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575 results on '"JOHNSON, J. S."'

3. THE GLOBAL AEROSOL SYNTHESIS AND SCIENCE PROJECT (GASSP) : Measurements and Modeling to Reduce Uncertainty

Author

Reddington, C. L., Carslaw, K. S., Stier, P., Schutgens, N., Coe, H., Liu, D., Allan, J., Browse, J., Pringle, K. J., Lee, L. A., Yoshioka, M., Johnson, J. S., Regayre, L. A., Spracklen, D. V., Mann, G. W., Clarke, A., Hermann, M., Henning, S., Wex, H., Kristensen, T. B., Leaitch, W. R., Pöschl, U., Rose, D., Andreae, M. O., Schmale, J., Kondo, Y., Oshima, N., Schwarz, J. P., Nenes, A., Anderson, B., Roberts, G. C., Snider, J. R., Leck, C., Quinn, P. K., Chi, X., Ding, A., Jimenez, J. L., and Zhang, Q.

Published
2017

7. Simulating organic aerosol in Delhi with WRF-Chem using the volatility-basis-set approach:exploring model uncertainty with a Gaussian process emulator

Author

Reyes-Villegas, E., Lowe, D., Johnson, J. S., Carslaw, K. S., Darbyshire, E., Flynn, Michael, Allan, J. D., Coe, Hugh, Chen, Y., Wild, O., Archer-Nicholls, Scott, Archibald, A., Singh, S., Shrivastava, M., Zaveri, R. A., Singh, Vikas, Beig, G., Sokhi, R., McFiggans, G., Reyes-Villegas, E., Lowe, D., Johnson, J. S., Carslaw, K. S., Darbyshire, E., Flynn, Michael, Allan, J. D., Coe, Hugh, Chen, Y., Wild, O., Archer-Nicholls, Scott, Archibald, A., Singh, S., Shrivastava, M., Zaveri, R. A., Singh, Vikas, Beig, G., Sokhi, R., and McFiggans, G.

Abstract

The nature and origin of organic aerosol in the atmosphere remain unclear. The gas–particle partitioning of semi-volatile organic compounds (SVOCs) that constitute primary organic aerosols (POAs) and the multigenerational chemical aging of SVOCs are particularly poorly understood. The volatility basis set (VBS) approach, implemented in air quality models such as WRF-Chem (Weather Research and Forecasting model with Chemistry), can be a useful tool to describe emissions of POA and its chemical evolution. However, the evaluation of model uncertainty and the optimal model parameterization may be expensive to probe using only WRF-Chem simulations. Gaussian process emulators, trained on simulations from relatively few WRF-Chem simulations, are capable of reproducing model results and estimating the sources of model uncertainty within a defined range of model parameters. In this study, a WRF-Chem VBS parameterization is proposed; we then generate a perturbed parameter ensemble of 111 model runs, perturbing 10 parameters of the WRF-Chem model relating to organic aerosol emissions and the VBS oxidation reactions. This allowed us to cover the model's uncertainty space and to compare outputs from each run to aerosol mass spectrometer observations of organic aerosol concentrations and O:C ratios measured in New Delhi, India. The simulations spanned the organic aerosol concentrations measured with the aerosol mass spectrometer (AMS). However, they also highlighted potential structural errors in the model that may be related to unsuitable diurnal cycles in the emissions and/or failure to adequately represent the dynamics of the planetary boundary layer. While the structural errors prevented us from clearly identifying an optimized VBS approach in WRF-Chem, we were able to apply the emulator in the following two periods: the full period (1–29 May) and a subperiod period of 14:00–16:00 h LT (local time) on 1–29 May. The combination of emulator analysis and model evaluation metrics

Published
2023

8. Environmental control reduces white‐nose syndrome infection in hibernating bats.

Author

Sewall, B. J., Turner, G. G., Scafini, M. R., Gagnon, M. F., Johnson, J. S., Keel, M. K., Anis, E., Lilley, T. M., White, J. P., Hauer, C. L., and Overton, B. E.

Subjects
WHITE-nose syndrome, LITTLE brown bat, BAT diseases, BATS, PSEUDOGYMNOASCUS destructans
Abstract

Infectious diseases caused by invasive, environmentally persistent fungal pathogens have increasingly endangered global biodiversity, yet disease management remains a major conservation challenge. A prominent example is white‐nose syndrome (WNS), a disease caused by the invasive fungal pathogen Pseudogymnoascus destructans (Pd) that has devastated populations of multiple North American bat species, but for which few effective management tools exist. Here, we propose that strategies to delay environmental transmission of Pd during early winter could limit WNS disease effects across winter, benefitting bats. We used a small captive experiment and a multi‐year field trial on wild, free‐ranging bats to assess an environmental control strategy to manage Pd within its environmental reservoir in Pennsylvania, USA, where the pathogen has become endemic. The strategy centers on the application of Polyethylene Glycol 8000 (PEG) to roost substrates in summer, prior to bat hibernation, as a means to disrupt environmental transmission to bats in early winter. In the captive experiment, environmental transmission of Pd to immunologically naïve little brown myotis (Myotis lucifugus) occurred from roost substrates inoculated with Pd, but the application of PEG to these substrates effectively blocked this transmission. In the field trial, Pd load and infection extent both declined substantially in free‐ranging M. lucifugus after treatment relative to controls, with declines exceeding effects of inter‐site and inter‐annual variation. Pathogen prevalence and load also declined substantially after PEG treatment in big brown bats (Eptesicus fuscus). No negative effects of PEG treatment were observed in body condition or colony counts of bats or in the microbial community. Together, these results are consistent with effective environmental control of Pd and reduced WNS disease effects in bats within contaminated hibernacula. The results also highlight the potential of carefully designed environmental control strategies for managing environmentally persistent pathogens. [ABSTRACT FROM AUTHOR]

Published
2023
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14. Effects of three distinct two-week long diet strategies after transport on weaned pigs’ short and long-term welfare markers, behaviors and microbiota

Author

Parois, Séverine, Duttlinger, Allan, Richert, B. T., Lindemann, S. R., Johnson, J. S., Marchant-Forde, Jeremy, Livestock Behavior Research Unit, USDA-ARS : Agricultural Research Service, Physiologie, Environnement et Génétique pour l'Animal et les Systèmes d'Elevage [Rennes] (PEGASE), AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Purdue University, Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, and United States Department of Agriculture - Agricultural Research Service

Subjects
pig, stress, welfare, [SDV.BA.MVSA]Life Sciences [q-bio]/Animal biology/Veterinary medicine and animal Health, microbiote, microbiota, swine, bien-être animal, comportement animal, behaviour, animal welfare, porc
Abstract

International audience; Alternative feed supplements have shown promising effects in performance, but effects on welfare have had little evaluation. In the present study, we aimed at evaluating the effect of diet supplementation on welfare indicators. A total of 246 piglets were weaned and transported for a 12h. After transport, they were assigned to one of 3 diets fed for a 14-day period: A – an antibiotic diet including chlortetracycline and tiamulin, NA – a control diet without any antibiotic or feed supplement, GLN – a diet including 0.20% L-glutamine. After the 14-day period, all piglets were fed the same diet. Tear staining was measured 11 times post-weaning (from d0 to 147). Skin lesions were counted before and after weaning (d-2, 2 and 36). Novel object tests (NOT) were done in groups 4 times post-weaning (d17, 47, 85, 111). Samples for 16S microbial DNA composition were collected prior to transport (d0), following the 14-day period (d14) and at the conclusion of the nursery phase (d34). The NA pigs appeared less interested by novel objects. On d17, they avoided the object less than A pigs (P < 0.05). They spent less time exploring the object on d85 and took longer to interact with the object on d111 than A and GLN pigs (P < 0.05). NA pigs also appeared more sensitive to environment and management. They had larger tear stains than GLN pigs on d84 and 110 (P < 0.05). On d2, NA pigs had more lesions than A and GLN (P < 0.01). In terms of microbiota composition, GLN had higher -diversity than A and NA (P < 0.001). Differences between dietary treatments were absent at d0, were all demonstrated at d14 and disappeared at d34. Pearson correlations between aggression, stress and anxiety indicators and bacterial populations were medium to high from 0.31 to 0.69. The results demonstrate that short-term feeding strategy can have both short- and long-term effects on behavior and welfare, that may partly be explained by changes in gut microbiota composition. Supplementation with GLN appears to confer similar benefits to, and thus could be a viable alternative to dietary antibiotics.

Published
2020

39. Constraining Uncertainty in Aerosol Direct Forcing

Author

Watson‐Parris, D., primary, Bellouin, N., additional, Deaconu, L. T., additional, Schutgens, N. A. J., additional, Yoshioka, M., additional, Regayre, L. A., additional, Pringle, K. J., additional, Johnson, J. S., additional, Smith, C. J., additional, Carslaw, K. S., additional, and Stier, P., additional

Published
2020
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44. Compounds of Groups 15 (As, Sb, Bi) and Silicon Compounds

Author

Fleming, I., additional, Smith, M. D., additional, Burton, J. W., additional, Suzuki, H., additional, Ikegami, T., additional, Baines, K. M., additional, Samuel, M. S., additional, Meltzer, A., additional, Scheschkewitz, D., additional, Ottosson, H., additional, Rouf, A. M., additional, Ohshita, J., additional, Gaspar, P. P., additional, Zhou, D., additional, Pietruszka, J., additional, Hwu, J. R., additional, Ethiraj, K. S., additional, Hemeon, I., additional, Singer, R. D., additional, Nilsson, M., additional, Skrydstrup, T., additional, Jaspars, M., additional, Lukevics, E., additional, Pudova, O., additional, Kobayashi, S., additional, Manabe, K., additional, Ishitani, H., additional, Matsuo, J.-I., additional, White, J. D., additional, Carter, R. G., additional, Tamao, K., additional, Yoshida, J.-I., additional, Itami, K., additional, Ricci, A., additional, Comes-Franchini, M., additional, Moberg, C., additional, Adolfsson, H., additional, Kawachi, A., additional, Wang, D., additional, Chan, T. H., additional, North, M., additional, Page, P. C. B., additional, McKenzie, M. J., additional, Nahm Garrett, M., additional, Johnson, J. S., additional, Aoyama, T., additional, Shioiri, T., additional, Hari, Y., additional, Lawrence, N. J., additional, Aizpurua, J. M., additional, Palomo, C., additional, Whitham, G. H., additional, Hiyama, T., additional, Mori, A., additional, Pons, J.-M., additional, Kocienski, P. J., additional, Pornet, J., additional, Keay, B. A., additional, Oshima, K., additional, Landais, Y., additional, Billups, W. E., additional, Saini, R. K., additional, Ager, D. J., additional, Bennetau, B., additional, Sarkar, T. K., additional, Michael, J. P., additional, and de Koning, C. B., additional

Published
2002
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