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Huang L, Levintal E, Erikson CB, Coyotl A, Horwath WR, Dahlke HE, Mazza Rodrigues JL. Molecular and Dual-Isotopic Profiling of the Microbial Controls on Nitrogen Leaching in Agricultural Soils under Managed Aquifer Recharge. Environ Sci Technol 2023. [PMID: 37467434 PMCID: PMC10399200 DOI: 10.1021/acs.est.3c01356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/21/2023]
Abstract
Nitrate (NO3-) leaching is a serious health and ecological concern in global agroecosystems, particularly those under the application of agricultural-managed aquifer recharge (Ag-MAR); however, there is an absence of information on microbial controls affecting NO3- leaching outcomes. We combine natural dual isotopes of NO3- (15N/14N and 18O/16O) with metagenomics, quantitative polymerase chain reaction (PCR), and a threshold indicator taxa analysis (TITAN) to investigate the activities, taxon profiles, and environmental controls of soil microbiome associated with NO3- leaching at different depths from Californian vineyards under Ag-MAR application. The isotopic signatures demonstrated a significant priming effect (P < 0.01) of Ag-MAR on denitrification activities in the topsoil (0-10 cm), with a 12-25-fold increase of 15N-NO3- and 18O-NO3- after the first 24 h of flooding, followed by a sharp decrease in the enrichment of both isotopes with ∼80% decline in denitrification activities thereafter. In contrast, deeper soils (60-100 cm) showed minimal or no denitrification activities over the course of Ag-MAR application, thus resulting in 10-20-fold of residual NO3- being leached. Metagenomic profiling and laboratory microcosm demonstrated that both nitrifying and denitrifying groups, responsible for controlling NO3- leaching, decreased in abundance and potential activity rates with soil depth. TITAN suggested that Nitrosocosmicus and Bradyrhizobium, as the major nitrifier and denitrifier, had the highest and lowest tipping points with regard to the NO3- changes (P < 0.05), respectively. Overall, our study provides new insight into specific depth limitations of microbial controls on soil NO3- leaching in agroecosystems.
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Affiliation(s)
- Laibin Huang
- Department of Land, Air, and Water Resources, University of California, Davis, Davis, California 95616, United States
| | - Elad Levintal
- Department of Land, Air, and Water Resources, University of California, Davis, Davis, California 95616, United States
| | - Christian Bernard Erikson
- Department of Land, Air, and Water Resources, University of California, Davis, Davis, California 95616, United States
| | - Adolfo Coyotl
- Department of Land, Air, and Water Resources, University of California, Davis, Davis, California 95616, United States
| | - William R Horwath
- Department of Land, Air, and Water Resources, University of California, Davis, Davis, California 95616, United States
| | - Helen E Dahlke
- Department of Land, Air, and Water Resources, University of California, Davis, Davis, California 95616, United States
| | - Jorge L Mazza Rodrigues
- Department of Land, Air, and Water Resources, University of California, Davis, Davis, California 95616, United States
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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Moughan PJ, Wolfe RR. Determination of Dietary Amino Acid Digestibility in Humans. J Nutr 2019; 149:2101-2109. [PMID: 31529051 DOI: 10.1093/jn/nxz211] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Revised: 04/18/2019] [Accepted: 07/31/2019] [Indexed: 11/13/2022] Open
Abstract
Dietary amino acid digestibility is a fundamental measure of importance in protein quality evaluation. Determining amino acid digestibility in humans, as the disappearance of an amino acid across the total digestive tract, has been discredited. Extensive cecal and colonic microbial metabolism renders fecal estimates of amino acids misleading. True ileal amino acid digestibility determined at the end of the small intestine predicts amino acid uptake more accurately. Given that ileal digestibility determination cannot be undertaken routinely in humans, a pig-based assay has been developed and validated. The growing pig values for digestibility, however, relate to healthy adult humans and there is a need to be able to determine amino acid digestibility for humans with specific physiological states. To this end, isotope-based methods for determining dietary amino acid digestibility indirectly show promise but remain to be fully validated.
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Affiliation(s)
| | - Robert R Wolfe
- Department of Geriatrics, Reynolds Institute on Aging, University of Arkansas for Medical Science, Little Rock, AR, USA
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Blaire T, Bailliez A, Ben Bouallegue F, Bellevre D, Agostini D, Manrique A. Determination of the Heart-to-Mediastinum Ratio of 123I-MIBG Uptake Using Dual-Isotope ( 123I-MIBG/ 99mTc-Tetrofosmin) Multipinhole Cadmium-Zinc-Telluride SPECT in Patients with Heart Failure. J Nucl Med 2017. [PMID: 28646015 DOI: 10.2967/jnumed.117.194373] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The aim of this retrospective study was to compare the heart-to-mediastinum ratio (HMR) of 123I-metaiodobenzylguanidine (123I-MIBG) uptake obtained using a multipinhole cadmium-zinc-telluride (CZT) camera with that obtained using conventional planar imaging. Methods: Forty consecutive heart failure patients underwent planar acquisition 4 h after 123I-MIBG injection (191 ± 41 [mean ± SD] MBq). To localize the heart using the CZT camera, 99mTc-tetrofosmin (358 ± 177 MBq) was administered and dual-isotope acquisition was performed. The HMRs were calculated with conventional planar imaging (HMRplanar), with anterior reprojection images using the CZT camera (HMRreproj), and with transaxial reconstructed images using the CZT camera (HMRtransaxial). In a phantom study, we estimated a linear model fitting the CZT camera data to the planar data, and we applied it to provide corrected CZT camera-determined HMRs in patients (cHMRreproj and cHMRtransaxial). Results: Thirty-four men and 6 women (71 ± 9 y old) with ischemic (22 patients) and nonischemic (18 patients) heart failure completed the study. For 22 of the 40 patients (55%), the New York Heart Association classification was class II and the ejection fraction was 35% ± 9%. HMRreproj (1.12 ± 0.19) and HMRtransaxial (1.35 ± 0.34) were lower than HMRplanar (1.44 ± 0.14) (P < 0.0001 and P < 0.01, respectively). cHMRreproj (1.54 ± 0.09) and cHMRtransaxial (1.45 ± 0.14) were significantly different (P < 0.0001). Lin concordance correlation and Bland-Altman analysis demonstrated an almost perfect concordance and a high agreement between HMRplanar and cHMRtransaxial (P was not significant) but not between HMRplanar and cHMRreproj (P < 0.0001). Conclusion: This study demonstrated that determination of the late HMR of cardiac 123I-MIBG uptake using dual-isotope (123I and 99mTc) acquisition on a multipinhole CZT camera was feasible in patients with heart failure. However, this determination should be performed using transaxial reconstructed images and linear correction based on phantom data acquisitions.
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Affiliation(s)
- Tanguy Blaire
- Department of Nuclear Medicine, UF 5881, Groupement des Hôpitaux de l'Institut Catholique de Lille, Lomme, France .,Signalisation, Électrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, UNICAEN, Normandie Université, Caen, France.,Department of Nuclear Medicine, IRIS, Polyclinique du Bois, Lille, France
| | - Alban Bailliez
- Department of Nuclear Medicine, UF 5881, Groupement des Hôpitaux de l'Institut Catholique de Lille, Lomme, France.,Signalisation, Électrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, UNICAEN, Normandie Université, Caen, France.,Department of Nuclear Medicine, IRIS, Polyclinique du Bois, Lille, France
| | | | | | - Denis Agostini
- Signalisation, Électrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, UNICAEN, Normandie Université, Caen, France.,Department of Nuclear Medicine, CHU Cote de Nacre, Caen, France
| | - Alain Manrique
- Signalisation, Électrophysiologie et Imagerie des Lésions d'Ischémie-Reperfusion Myocardique, UNICAEN, Normandie Université, Caen, France.,Department of Nuclear Medicine, CHU Cote de Nacre, Caen, France
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