7 research outputs found

    Radioactive Source Localization Using True-Range Multilateration Methods

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    The detection of holdup in a nuclear material processing facility that utilizes glove boxes is both important and challenging. Being able to determine the position of holdup in a glovebox can help streamline the efficiency of the processes. Various localization methods have been developed to determine the location and amount of radioactive material in a wide variety of scenarios including wide scale aerial and laboratory scale localization. This research describes the various methods and approaches used to localize a gamma source and a neutron source using true-range multilateration. The developed algorithm is based on the inverse-square law relationship between the source intensity measured by a detector and the distance the source is from that detector. This algorithm was developed in Python, was tested using MCNP simulations and experimentally verified using a mock glovebox. The results of the MCNP simulations shows that the algorithm’s best method and approach was able to localize a gamma source within 17.5 ± 12.8 cm and a neutron source within an average of 17.6 ± 17.2 cm. Through experiment the algorithm’s best method and approach was able to localize a gamma source within an average of 7.0 ± 5.4 cm and 5.4 ± 2.5 cm for a neutron source. For gamma localization this algorithm was a 119.47% improvement over previously reported techniques. However, compared to previous neutron localization methods, this algorithm performed 149.71% worse than previously reported techniques which does not make it a viable candidate for real-time localization of neutron sources

    Evaluation of the bacterial ocular surface microbiome in ophthalmologically normal dogs prior to and following treatment with topical neomycin-polymyxin-bacitracin.

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    The ocular surface microbiome of veterinary species has not been thoroughly characterized using molecular-based techniques, such as next generation sequencing (NGS), as the vast majority of studies have utilized traditional culture-based techniques. To date, there is one pilot study evaluating the ocular surface of healthy dogs using NGS. Furthermore, alterations in the ocular surface microbiome over time and after topical antibiotic treatment are unknown. The objectives of this study were to describe the bacterial composition of the ocular surface microbiome in clinically normal dogs, and to determine if microbial community changes occur over time or following topical antibiotic therapy. Topical neomycin-polymyxin-bacitracin ophthalmic ointment was applied to one eye each of 13 adult dogs three times daily for seven days, while contralateral eyes served as untreated controls. The inferior conjunctival fornix of both eyes was sampled via swabbing at baseline prior to antibiotic therapy (day 0), after 1 week of treatment (day 7), and 4 weeks after discontinuing treatment (day 35). Genomic DNA was extracted from the conjunctival swabs and primers targeting the V4 region of bacterial 16S rRNA genes were used to generate amplicon libraries, which were then sequenced on an Illumina platform. Data were analyzed using Quantitative Insights Into Molecular Ecology (QIIME 2.0). At baseline, the most relatively abundant phyla sequenced were Proteobacteria (49.7%), Actinobacteria (25.5%), Firmicutes (12%), Bacteroidetes (7.5%), and Fusobacteria (1.4%). The most common families detected were Pseudomonadaceae (13.2%), Micrococcaceae (12%), Pasteurellaceae (6.9%), Microbacteriaceae (5.2%), Enterobacteriaceae (3.9%), Neisseriaceae (3.5%), and Corynebacteriaceae (3.3%). Alpha and beta diversity measurements did not differ in both control and treatment eyes over time. This report examines the temporal stability of the canine ocular surface microbiome. The major bacterial taxa on the canine ocular surface remained consistent over time and following topical antibiotic therapy

    Untargeted fecal metabolome analysis in obese dogs after weight loss achieved by feeding a high-fiber-high-protein diet

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    INTRODUCTION: In humans and companion animals, obesity is accompanied by metabolic derangements. Studies have revealed differences in the composition of the fecal microbiome between obese dogs and those with an ideal body weight. OBJECTIVES: We have previously reported that the fecal microbiome in obese dogs changes after controlled weight reduction, induced by feeding a diet high in fiber and protein. Despite these findings, it is unclear if taxonomic differences infer differences at the functional level between obese dogs and those with an ideal body weight. METHODOLOGY: Untargeted fecal metabolome analysis was performed on dogs with obesity before and after weight loss achieved by feeding a high-fiber-high-protein diet. RESULTS: Fecal metabolome analysis revealed a total of 13 compounds that changed in concentration in obese dogs after weight loss. Of these compounds, metabolites associated with bacterial metabolism decreased after weight loss including purine, L-(-)-methionine, coumestrol, and the alkaloids 1-methylxanthine and trigonelline. Conversely, the polyphenols (-)-epicatechin and matairesinol and the quinoline derivatives 1,5-isoquinolinediol and 2-hydroxiquinoline increased after weight loss. CONCLUSION: These results suggest differences in intestinal microbiome at the functional level after weight loss, but further studies are needed to determine the role of these compounds in the etiology of obesity and weight loss. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s11306-021-01815-1

    Fecal microbiota in client-owned obese dogs changes after weight loss with a high-fiber-high-protein diet

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    Background The fecal microbiota from obese individuals can induce obesity in animal models. In addition, studies in humans, animal models and dogs have revealed that the fecal microbiota of subjects with obesity is different from that of lean subjects and changes after weight loss. However, the impact of weight loss on the fecal microbiota in dogs with obesity has not been fully characterized. Methods In this study, we used 16S rRNA gene sequencing to investigate the differences in the fecal microbiota of 20 pet dogs with obesity that underwent a weight loss program. The endpoint of the weight loss program was individually tailored to the ideal body weight of each dog. In addition, we evaluated the qPCR based Dysbiosis Index before and after weight loss. Results After weight loss, the fecal microbiota structure of dogs with obesity changed significantly (weightedANOSIM; p = 0.016, R = 0.073), showing an increase in bacterial richness (p = 0.007), evenness (p = 0.007) and the number of bacterial species (p = 0.007). The fecal microbiota composition of obese dogs after weight loss was characterized by a decrease in Firmicutes (92.3% to 78.2%, q = 0.001), and increase in Bacteroidetes (1.4% to 10.1%, q = 0.002) and Fusobacteria (1.6% to 6.2%, q = 0.040). The qPCR results revealed an overall decrease in the Dysbiosis Index, driven mostly due to a significant decrease in E. coli (p = 0.030), and increase in Fusobacterium spp. (p = 0.017). Conclusion The changes observed in the fecal microbiota of dogs with obesity after weight loss with a weight loss diet rich in fiber and protein were in agreement with previous studies in humans, that reported an increase of bacterial biodiversity and a decrease of the ratio Firmicutes/Bacteroidetes. </jats:sec
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