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Granger SJ, May V, Hammack SE, Akman E, Jobson SA, Olson EA, Pernia CD, Daskalakis NP, Ravichandran C, Carlezon WA, Ressler KJ, Rauch SL, Rosso IM. Circulating PACAP levels are associated with altered imaging measures of entorhinal cortex neurite density in posttraumatic stress disorder. Eur J Psychotraumatol 2024; 15:2335793. [PMID: 38590134 PMCID: PMC11005872 DOI: 10.1080/20008066.2024.2335793] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 03/18/2024] [Indexed: 04/10/2024] Open
Abstract
Introduction: Pituitary adenylate cyclase-activating polypeptide (PACAP) regulates plasticity in brain systems underlying arousal and memory and is associated with posttraumatic stress disorder (PTSD). Research in animal models suggests that PACAP modulates entorhinal cortex (EC) input to the hippocampus, contributing to impaired contextual fear conditioning. In PTSD, PACAP is associated with higher activity of the amygdala to threat stimuli and lower functional connectivity of the amygdala and hippocampus. However, PACAP-affiliated structural alterations of these regions have not been investigated in PTSD. Here, we examined whether peripheral PACAP levels were associated with neuronal morphology of the amygdala and hippocampus (primary analyses), and EC (secondary) using Neurite Orientation Dispersion and Density Imaging.Methods: Sixty-four (44 female) adults (19 to 54 years old) with DSM-5 Criterion A trauma exposure completed the Clinician-Administered PTSD Scale (CAPS-5), a blood draw, and magnetic resonance imaging. PACAP38 radioimmunoassay was performed and T1-weighted and multi-shell diffusion-weighted images were acquired. Neurite Density Index (NDI) and Orientation Dispersion Index (ODI) were quantified in the amygdala, hippocampus, and EC. CAPS-5 total score and anxious arousal score were used to test for clinical associations with brain structure.Results: Higher PACAP levels were associated with greater EC NDI (β = 0.0099, q = 0.032) and lower EC ODI (β = -0.0073, q = 0.047), and not hippocampal or amygdala measures. Neither EC NDI nor ODI was associated with clinical measures.Conclusions: Circulating PACAP levels were associated with altered neuronal density of the EC but not the hippocampus or amygdala. These findings strengthen evidence that PACAP may impact arousal-associated memory circuits in PTSD.
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Affiliation(s)
- Steven J. Granger
- Division of Depression and Anxiety Disorders, McLean Hospital, Belmont, MA, USA
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Victor May
- Larner College of Medicine, University of Vermont, Burlington, VT, USA
| | | | - Eylül Akman
- Division of Depression and Anxiety Disorders, McLean Hospital, Belmont, MA, USA
| | - Sydney A. Jobson
- Division of Depression and Anxiety Disorders, McLean Hospital, Belmont, MA, USA
| | - Elizabeth A. Olson
- Division of Depression and Anxiety Disorders, McLean Hospital, Belmont, MA, USA
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Cameron D. Pernia
- Division of Depression and Anxiety Disorders, McLean Hospital, Belmont, MA, USA
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA
- Basic Neuroscience Division, McLean Hospital, Belmont, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Nikos P. Daskalakis
- Division of Depression and Anxiety Disorders, McLean Hospital, Belmont, MA, USA
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA
- Basic Neuroscience Division, McLean Hospital, Belmont, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Caitlin Ravichandran
- Division of Depression and Anxiety Disorders, McLean Hospital, Belmont, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
- Lurie Center for Autism, Massachusetts General Hospital, Lexington, MA, USA
| | - William A. Carlezon
- Basic Neuroscience Division, McLean Hospital, Belmont, MA, USA
- Department of Pediatrics, Harvard Medical School, Boston, MA, USA
| | - Kerry J. Ressler
- Division of Depression and Anxiety Disorders, McLean Hospital, Belmont, MA, USA
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Scott L. Rauch
- Division of Depression and Anxiety Disorders, McLean Hospital, Belmont, MA, USA
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Isabelle M. Rosso
- Division of Depression and Anxiety Disorders, McLean Hospital, Belmont, MA, USA
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA
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Upadhayay HR, Granger SJ, Collins AL. Comparison of sediment biomarker signatures generated using time-integrated and discrete suspended sediment samples. Environ Sci Pollut Res Int 2024; 31:22431-22440. [PMID: 38407710 PMCID: PMC10997529 DOI: 10.1007/s11356-024-32533-5] [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] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Accepted: 02/14/2024] [Indexed: 02/27/2024]
Abstract
Sediment source fingerprinting using biomarker properties has led to new insights in our understanding of land use contributions to time-integrated suspended sediment samples at catchment scale. A time-integrated mass-flux sampler (TIMS; also known as the 'Phillips' sampler), a cost-effective approach for suspended sediment collection in situ. Such samplers are widely being used to collect sediment samples for source fingerprinting purposes, including studies using biomarkers as opposed to more conventional tracer properties. Here, we assessed the performance of TIMS for collecting representative sediment samples for biomarkers during high discharge events in a small lowland grassland-dominated catchment. Concentrations of long odd-chain n-alkanes (> C23) and both saturated free and bound fatty acids (C14-C32), as well as compound-specific 13C were compared between sediment collected by both TIMS and autosamplers (ISCO). The results showed that concentrations of alkanes, free fatty acids, and bound fatty acids are consistently comparable between TIMS and ISCO suspended sediment samples. Similarly, compound-specific 13C signals were not found to be significantly different in the suspended sediment samples collected using the different samplers. However, different magnitudes of resemblance in biomarker concentrations and compositions between the samples collected using the two sediment collection methods were confirmed by overlapping index and symmetric coordinates-based correlation analysis. Here, the difference is attributed to the contrasting temporal basis of TIMS (time-integrated) vs. ISCO (discrete) samples, as well as potential differences in the particle sizes collected by these different sediment sampling methods. Nevertheless, our findings suggest that TIMS can be used to generate representative biomarker data for suspended sediment samples collected during high discharge events.
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Affiliation(s)
- Hari Ram Upadhayay
- Net Zero and Resilient Farming, Rothamsted Research, North Wyke, Okehampton, EX20 2SB, UK.
| | - Steven J Granger
- Net Zero and Resilient Farming, Rothamsted Research, North Wyke, Okehampton, EX20 2SB, UK
| | - Adrian L Collins
- Net Zero and Resilient Farming, Rothamsted Research, North Wyke, Okehampton, EX20 2SB, UK
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Olson EA, Ahmad S, Granger SJ, Ashraf A, Pizzagalli DA, Rosso IM. Anhedonia and Delay Discounting: Differing Patterns of Brain-Behavior Relationships in Healthy Control Participants Versus Individuals With Posttraumatic Stress Disorder. Biol Psychiatry Cogn Neurosci Neuroimaging 2024; 9:80-90. [PMID: 37536568 PMCID: PMC10830883 DOI: 10.1016/j.bpsc.2023.07.013] [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] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 07/12/2023] [Accepted: 07/13/2023] [Indexed: 08/05/2023]
Abstract
BACKGROUND Anhedonia may contribute to individual differences in delay discounting (DD). In prior work, we found that higher anhedonia was associated with shallower DD in healthy control (HC) participants but steeper DD in individuals with posttraumatic stress disorder (PTSD). In this study, we aimed to directly compare the relationship between anhedonia and DD across groups and to identify functional brain correlates of this interaction. METHODS Participants (HC group: n = 23, DSM-5 PTSD group: n = 23) completed a questionnaire assessing anhedonia (Snaith-Hamilton Pleasure Scale [SHAPS]), task-based functional magnetic resonance imaging of decision making including DD, and resting-state functional magnetic resonance imaging. Task-based activity and resting-state functional connectivity were evaluated in reward-related regions that have also been implicated in PTSD (nucleus accumbens [NAcc], right anterior insula). RESULTS Higher SHAPS scores were associated with steeper DD in PTSD, but there was no relationship between DD and SHAPS in the HC group. There was a significant group-by-SHAPS interaction for NAcc activity, t31 = 2.92, p = .007: Greater NAcc activity when immediate rewards were chosen was associated with higher SHAPS in the PTSD group but lower SHAPS in the HC group. In resting-state functional connectivity, there was a group-by-SHAPS interaction between the NAcc seed and right parietal and frontal pole clusters. CONCLUSIONS These results extend prior findings that anhedonia is associated with steeper DD in PTSD and demonstrate that this behavioral finding occurs in the context of NAcc hyperactivity to immediate rewards and hyperconnectivity in anhedonic individuals with PTSD.
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Affiliation(s)
- Elizabeth A Olson
- Center for Depression, Anxiety and Stress Research, McLean Hospital, Belmont, Massachusetts; Department of Psychiatry, Harvard Medical School, Boston, Massachusetts.
| | - Subul Ahmad
- Center for Depression, Anxiety and Stress Research, McLean Hospital, Belmont, Massachusetts
| | - Steven J Granger
- Center for Depression, Anxiety and Stress Research, McLean Hospital, Belmont, Massachusetts; Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
| | - Aseelah Ashraf
- Center for Depression, Anxiety and Stress Research, McLean Hospital, Belmont, Massachusetts
| | - Diego A Pizzagalli
- Center for Depression, Anxiety and Stress Research, McLean Hospital, Belmont, Massachusetts; Department of Psychiatry, Harvard Medical School, Boston, Massachusetts; McLean Imaging Center, McLean Hospital, Belmont, Massachusetts
| | - Isabelle M Rosso
- Center for Depression, Anxiety and Stress Research, McLean Hospital, Belmont, Massachusetts; Department of Psychiatry, Harvard Medical School, Boston, Massachusetts
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Granger SJ, May V, Hammack SE, Akman E, Jobson SA, Olson EA, Pernia CD, Daskalakis NP, Ravichandran C, Carlezon WA, Ressler KJ, Rauch SL, Rosso IM. Circulating PACAP levels are associated with altered imaging measures of entorhinal cortex neurite density in posttraumatic stress disorder. medRxiv 2023:2023.08.31.23294894. [PMID: 37693514 PMCID: PMC10491384 DOI: 10.1101/2023.08.31.23294894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Background Pituitary adenylate cyclase-activating polypeptide (PACAP) regulates plasticity in brain systems underlying arousal and memory and is associated with posttraumatic stress disorder (PTSD). Research in animal models suggests that PACAP modulates entorhinal cortex (EC) input to the hippocampus, contributing to impaired contextual fear conditioning. In PTSD, PACAP is associated with higher activity of the amygdala to threat stimuli and lower functional connectivity of the amygdala and hippocampus. However, PACAP-affiliated structural alterations of these regions have not been reported. Here, we examined whether peripheral PACAP levels were associated with neuronal morphology of the amygdala and hippocampus (primary analysis), and EC (secondary analysis) using Neurite Orientation Dispersion and Density Imaging. Methods Sixty-four (44 female) adults (19 to 54 years old) with DSM-5 Criterion A trauma exposure completed the Clinician-Administered PTSD Scale (CAPS-5), a blood draw, and magnetic resonance imaging. PACAP38 radioimmunoassay was performed and T1-weighted and multi-shell diffusion- weighted images were acquired. Neurite Density Index (NDI) and Orientation Dispersion Index (ODI) were quantified in the amygdala, hippocampus, and EC. CAPS-5 total score and anxious arousal score were used to test for clinical associations with brain structure. Results Higher PACAP levels in blood were associated with greater EC NDI (β=0.31, q=0.034) and lower EC ODI (β=-0.30, q=0.042) and not hippocampal or amygdala measures. Neither EC NDI nor ODI was associated with clinical measures. Conclusions Circulating PACAP levels were associated with altered neuronal density of the EC but not hippocampus or amygdala. These findings strengthen evidence that PACAP may impact arousal- associated memory circuits.
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Granger SJ, Upadhayay HR, Collins AL. Hydro-chemical responses at different scales in a rural catchment, UK, and implications for managing the unintended consequences of agriculture. Environ Res 2023; 228:115826. [PMID: 37011801 DOI: 10.1016/j.envres.2023.115826] [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] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 03/06/2023] [Accepted: 03/31/2023] [Indexed: 05/16/2023]
Abstract
Diffuse pollutant transfers from agricultural land often constitute the bulk of annual loads in catchments and storm events dominate these fluxes. There remains a lack of understanding of how pollutants move through catchments at different scales. This is critical if the mismatch between the scales used to implement on-farm management strategies, compared to those used for assessment of environmental quality, is to be addressed. The aim of this study was to understand how the mechanisms of pollutant export may change when assessed at different scales and the corresponding implications for on-farm management strategies. A study was conducted within a 41 km2 catchment containing 3 nested sub-catchments, instrumented to monitor discharge and various water quality parameters. Storm data over a 24-month period were analysed and hysteresis (HI) and flushing (FI) indices calculated for two water quality variables that are typically of environmental significance; NO3-N and suspended sediment (SSC). For SSC, increasing spatial scale had little effect on the mechanistic interpretation of mobilisation and the associated on-farm management strategies. At the three smallest scales NO3-N was chemodynamic with the interpretation of dominant mechanisms changing seasonally. At these scales, the same on-farm management strategies would be recommended. However, at the largest scale, NO3-N appeared unaffected by season and chemostatic. This would lead to a potentially very different interpretation and subsequent on-farm measures. The results presented here underscore the benefits of nested monitoring for extracting mechanistic understanding of agricultural impacts on water quality. The application of HI and FI indicates that monitoring at smaller scales is crucial. At large scales, the complexity of the catchment hydrochemical response means that mechanisms become obscured. Smaller catchments more likely represent critical areas within larger catchments where mechanistic understanding can be extracted from water quality monitoring and used to underpin the selection of on-farm mitigation measures.
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Affiliation(s)
- S J Granger
- Net Zero and Resilient Farming, Rothamsted Research, North Wyke, Okehampton, Devon, EX20 2SB, United Kingdom.
| | - H R Upadhayay
- Net Zero and Resilient Farming, Rothamsted Research, North Wyke, Okehampton, Devon, EX20 2SB, United Kingdom
| | - A L Collins
- Net Zero and Resilient Farming, Rothamsted Research, North Wyke, Okehampton, Devon, EX20 2SB, United Kingdom
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Granger SJ, Colon-Perez L, Larson MS, Bennett IJ, Phelan M, Keator DB, Janecek JT, Sathishkumar MT, Smith AP, McMillan L, Greenia D, Corrada MM, Kawas CH, Yassa MA. Reduced structural connectivity of the medial temporal lobe including the perforant path is associated with aging and verbal memory impairment. Neurobiol Aging 2023; 121:119-128. [PMID: 36434930 DOI: 10.1016/j.neurobiolaging.2022.10.012] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 10/20/2022] [Accepted: 10/22/2022] [Indexed: 11/11/2022]
Abstract
The perforant path, the white matter bundle connecting the entorhinal cortex (ERC) with the hippocampal formation deteriorates with age-related cognitive decline. Previous investigations using diffusion-weighted MRI to quantify perforant path integrity in-vivo have been limited due to image resolution or have quantified the perforant path using methods susceptible to partial volume effects such as the tensor model and without consideration of its 3-dimensional morphology. In this investigation, we use quantitative-anisotropy informed tractography derived from ultra-high resolution diffusion imaging (ZOOMit) to investigate structural connectivity of the perforant path and other medial temporal lobe (MTL) pathways in older adults (63 to 98 years old, n = 51). We show that graph density within the MTL declines with age and is associated with lower delayed recall performance. We also show that older age and poorer delayed recall are associated with reduced streamlines connecting the ERC and dentate gyrus of the hippocampus (the putative perforant path). This work suggest that intra-MTL connectivity may new candidate biomarkers for age-related cognitive decline.
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Affiliation(s)
- Steven J Granger
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA
| | - Luis Colon-Perez
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA
| | - Myra Saraí Larson
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA
| | - Ilana J Bennett
- Department of Psychology, University of California, Riverside, CA
| | - Michael Phelan
- Department of Statistics, University of California, Irvine, CA
| | - David B Keator
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA
| | - John T Janecek
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA
| | - Mithra T Sathishkumar
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA
| | - Anna P Smith
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA
| | - Liv McMillan
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA
| | - Dana Greenia
- Department of Neurology, University of California, Irvine, CA
| | - Maria M Corrada
- Department of Neurology, University of California, Irvine, CA
| | - Claudia H Kawas
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA; Department of Neurology, University of California, Irvine, CA
| | - Michael A Yassa
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA; Department of Neurobiology and Behavior, University of California, Irvine, CA; Department of Psychiatry and Human Behavior, University of California, Irvine, CA; Department of Neurology, University of California, Irvine, CA.
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Rizvi B, Sathishkumar M, Kim S, Márquez F, Granger SJ, Larson MS, Miranda BA, Hollearn MK, McMillan L, Nan B, Tustison NJ, Lao PJ, Brickman AM, Greenia D, Corrada MM, Kawas CH, Yassa MA. Posterior white matter hyperintensities are associated with reduced medial temporal lobe subregional integrity and long-term memory in older adults. Neuroimage Clin 2022; 37:103308. [PMID: 36586358 PMCID: PMC9830310 DOI: 10.1016/j.nicl.2022.103308] [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] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 12/21/2022] [Accepted: 12/26/2022] [Indexed: 12/29/2022]
Abstract
White matter hyperintensities are a marker of small vessel cerebrovascular disease that are strongly related to cognition in older adults. Similarly, medial temporal lobe atrophy is well-documented in aging and Alzheimer's disease and is associated with memory decline. Here, we assessed the relationship between lobar white matter hyperintensities, medial temporal lobe subregional volumes, and hippocampal memory in older adults. We collected MRI scans in a sample of 139 older adults without dementia (88 females, mean age (SD) = 76.95 (10.61)). Participants were administered the Rey Auditory Verbal Learning Test (RAVLT). Regression analyses tested for associations among medial temporal lobe subregional volumes, regional white matter hyperintensities and memory, while adjusting for age, sex, and education and correcting for multiple comparisons. Increased occipital white matter hyperintensities were related to worse RAVLT delayed recall performance, and to reduced CA1, dentate gyrus, perirhinal cortex (Brodmann area 36), and parahippocampal cortex volumes. These medial temporal lobe subregional volumes were related to delayed recall performance. The association of occipital white matter hyperintensities with delayed recall performance was fully mediated statistically only by perirhinal cortex volume. These results suggest that white matter hyperintensities may be associated with memory decline through their impact on medial temporal lobe atrophy. These findings provide new insights into the role of vascular pathologies in memory loss in older adults and suggest that future studies should further examine the neural mechanisms of these relationships in longitudinal samples.
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Affiliation(s)
- Batool Rizvi
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA, USA; Department of Neurobiology and Behavior, University of California, Irvine, CA, USA
| | - Mithra Sathishkumar
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA, USA; Department of Neurobiology and Behavior, University of California, Irvine, CA, USA
| | - Soyun Kim
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA, USA; Department of Neurobiology and Behavior, University of California, Irvine, CA, USA
| | - Freddie Márquez
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA, USA; Department of Neurobiology and Behavior, University of California, Irvine, CA, USA
| | - Steven J Granger
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA, USA; Department of Neurobiology and Behavior, University of California, Irvine, CA, USA
| | - Myra S Larson
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA, USA; Department of Neurobiology and Behavior, University of California, Irvine, CA, USA
| | - Blake A Miranda
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA, USA; Department of Neurobiology and Behavior, University of California, Irvine, CA, USA
| | - Martina K Hollearn
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA, USA; Department of Neurobiology and Behavior, University of California, Irvine, CA, USA
| | - Liv McMillan
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA, USA; Department of Neurobiology and Behavior, University of California, Irvine, CA, USA
| | - Bin Nan
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA, USA; Department of Statistics, University of California, Irvine, Irvine, CA, USA
| | - Nicholas J Tustison
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA, USA; Department of Neurobiology and Behavior, University of California, Irvine, CA, USA; Department of Radiology and Medical Imaging, University of Virginia, Charlottesville, VA, USA
| | - Patrick J Lao
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA; Gertrude H. Sergievsky Center, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Adam M Brickman
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA; Gertrude H. Sergievsky Center, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA; Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Dana Greenia
- Department of Neurology, School of Medicine, University of California, Irvine, CA, USA
| | - Maria M Corrada
- Department of Neurology, School of Medicine, University of California, Irvine, CA, USA; Department of Epidemiology, University of California, Irvine, CA, USA
| | - Claudia H Kawas
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA, USA; Department of Neurobiology and Behavior, University of California, Irvine, CA, USA; Department of Neurology, School of Medicine, University of California, Irvine, CA, USA
| | - Michael A Yassa
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, CA, USA; Department of Neurobiology and Behavior, University of California, Irvine, CA, USA; Department of Neurology, School of Medicine, University of California, Irvine, CA, USA.
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Granger SJ, Colon-Perez L, Larson MS, Phelan M, Keator DB, Janecek JT, Sathishkumar MT, Smith AP, McMillan L, Greenia D, Corrada MM, Kawas CH, Yassa MA. Hippocampal dentate gyrus integrity revealed with ultrahigh resolution diffusion imaging predicts memory performance in older adults. Hippocampus 2022; 32:627-638. [PMID: 35838075 PMCID: PMC10510739 DOI: 10.1002/hipo.23456] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 05/26/2022] [Accepted: 06/30/2022] [Indexed: 11/08/2022]
Abstract
Medial temporal lobe (MTL) atrophy is a core feature of age-related cognitive decline and Alzheimer's disease (AD). While regional volumes and thickness are often used as a proxy for neurodegeneration, they lack the sensitivity to serve as an accurate diagnostic test and indicate advanced neurodegeneration. Here, we used a submillimeter resolution diffusion weighted MRI sequence (ZOOMit) to quantify microstructural properties of hippocampal subfields in older adults (63-98 years old) using tensor derived measures: fractional anisotropy (FA) and mean diffusivity (MD). We demonstrate that the high-resolution sequence, and not a standard resolution sequence, identifies dissociable profiles for CA1, dentate gyrus (DG), and the collateral sulcus. Using ZOOMit, we show that advanced age is associated with increased MD of the CA1 and DG as well as decreased FA of the DG. Increased MD of the DG, reflecting decreased cellular density, mediated the relationship between age and word list recall. Further, increased MD in the DG, but not DG volume, was linked to worse spatial pattern separation. Our results demonstrate that ultrahigh-resolution diffusion imaging enables the detection of microstructural differences in hippocampal subfield integrity and will lead to novel insights into the mechanisms of age-related memory loss.
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Affiliation(s)
- Steven J. Granger
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
| | - Luis Colon-Perez
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
| | - Myra Saraí Larson
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
| | - Michael Phelan
- UC Institute for Memory Impairments and Neurological Disorders, University of California, Irvine 92697
| | - David B. Keator
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697
| | - John T. Janecek
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
| | - Mithra T. Sathishkumar
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
| | - Anna P. Smith
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
| | - Liv McMillan
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
| | - Dana Greenia
- Department of Neurology, University of California, Irvine 92697
| | | | - Claudia H. Kawas
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
- Department of Neurology, University of California, Irvine 92697
| | - Michael A. Yassa
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697
- Department of Neurobiology and Behavior, University of California, Irvine 92697
- Department of Psychiatry and Human Behavior, University of California, Irvine, CA 92697
- Department of Neurology, University of California, Irvine 92697
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9
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Upadhayay HR, Zhang Y, Granger SJ, Micale M, Collins AL. Prolonged heavy rainfall and land use drive catchment sediment source dynamics: Appraisal using multiple biotracers. Water Res 2022; 216:118348. [PMID: 35378448 DOI: 10.1016/j.watres.2022.118348] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 03/14/2022] [Accepted: 03/21/2022] [Indexed: 06/14/2023]
Abstract
Excessive sediment loss degrades freshwater quality and is prone to further elevation and variable source contributions due to the combined effect of extreme rainfall and differing land uses. To quantify erosion and sediment source responses across scales, this study integrated work at both field and catchment scale for two hydrologically contrasting winters (2018-19 and 2019-20). Sediment load was estimated at the field scale (grassland-arable conversion system). Sediment source apportionment work was undertaken at the catchment scale (4.5 km2) and used alkanes, and both free and bound fatty acid carbon isotope signatures as diagnostic fingerprints to distinguish sediment sources: arable, pasture, woodland and stream banks. Sediment source apportionment based on bound fatty acids revealed a substantial shift in contributions, from stream banks dominating (70 ± 5%) in winter 2018-19, to arable land dominating (52 ± 7%) in the extreme wet winter 2019-20. Increases in sediment contributions from arable (∼3.9 times) and pasture (∼2.4 times) land at the catchment outlet during the winter 2019-20 were consistent with elevated sediment losses monitored at the field scale which indicated that low-magnitude high frequency rainfall alone increased sediment loss even from pasture by 350%. In contrast, carbon isotope signatures of alkanes and free fatty acids consistently estimated stream banks as a dominant source (i.e., ∼36% and ∼70% respectively) for both winters regardless of prolonged rainfall in winter 2019-20. Beyond quantifying the shifts in field scale sediment load and catchment scale sediment sources due to the changes in rainfall patterns, our results demonstrate valuable insight into how the fate of biotracers in soil and sediment manifests in the δ13C values of homologues and, in turn, their role in information gain for estimating sediment source contributions. Discrepancies in the estimated sediment source contributions using different biotracers indicate that without a careful appreciation of their biogeochemical limitations, erroneous interpretation of sediment source contributions can undermine management strategies for delivering more sustainable and resilient agriculture.
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Affiliation(s)
- Hari Ram Upadhayay
- Sustainable Agriculture Sciences, Rothamsted Research, North Wyke, Okehampton, EX20 2SB, United Kingdom.
| | - Yusheng Zhang
- Sustainable Agriculture Sciences, Rothamsted Research, North Wyke, Okehampton, EX20 2SB, United Kingdom
| | - Steven J Granger
- Sustainable Agriculture Sciences, Rothamsted Research, North Wyke, Okehampton, EX20 2SB, United Kingdom
| | - Mafalda Micale
- Sustainable Agriculture Sciences, Rothamsted Research, North Wyke, Okehampton, EX20 2SB, United Kingdom; Department of Agriculture, Università degli Studi Mediterranea di Reggio Calabria, Reggio Calabria, Feo di Vito 89122, Italy
| | - Adrian L Collins
- Sustainable Agriculture Sciences, Rothamsted Research, North Wyke, Okehampton, EX20 2SB, United Kingdom
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10
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Granger SJ, Adams JG, Kark SM, Sathishkumar MT, Chen IY, Benca RM, McMillan L, Janecek JT, Yassa MA. Latent anxiety in clinical depression is associated with worse recognition of emotional stimuli. J Affect Disord 2022; 301:368-377. [PMID: 34999127 DOI: 10.1016/j.jad.2022.01.009] [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] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 12/17/2021] [Accepted: 01/02/2022] [Indexed: 10/19/2022]
Abstract
BACKGROUND Major Depressive Disorder, characterized by cognitive affective biases, is a considerable public health challenge. Past work has shown that higher depressive symptoms are associated with augmented memory of negative stimuli. In contrast, anxiety symptoms have been associated with overgeneralization of emotional memories. Given the high comorbidity of depression and anxiety, it is critical to understand how cognitive affective biases are differentially associated with clinical symptoms. METHOD We used continuous measures of depression (Beck Depression Inventory [BDI-II]) and anxiety (Beck Anxiety Inventory [BAI]) to evaluate an adult sample (N = 79; 18-41 years old, 58 female). Emotional memory discrimination and recognition memory were tested using an emotional discrimination task. We applied exploratory factor analysis to questions from the BAI and BDI-II to uncover latent constructs consisting of negative affect, anhedonia, somatic anxiety, and cognitive anxiety. RESULTS We report evidence that anxious symptoms were associated with impaired recognition of negative items after accounting for age and sex. Our exploratory factor analysis revealed that impaired negative item recognition is largely associated with somatic and cognitive anxiety factors. LIMITATIONS Interpretations in a mixed pathology sample, especially given collinearity among factors, may be difficult. CONCLUSIONS We provide evidence that somatic and cognitive anxiety are related to impaired recognition memory for negative stimuli. Future clinical investigations should uncover the neurobiological basis supporting the link between recognition of negative stimuli and somatic/cognitive symptoms of anxiety.
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Affiliation(s)
- Steven J Granger
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697, USA; Department of Neurobiology and Behavior, University of California, Irvine 92697, USA
| | - Joren G Adams
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697, USA; Department of Neurobiology and Behavior, University of California, Irvine 92697, USA
| | - Sarah M Kark
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697, USA; Department of Neurobiology and Behavior, University of California, Irvine 92697, USA
| | - Mithra T Sathishkumar
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697, USA; Department of Neurobiology and Behavior, University of California, Irvine 92697, USA
| | - Ivy Y Chen
- Department of Psychiatry and Human Behavior, University of California, 1418 Biological Sciences 3, Irvine, CA 92697, USA
| | - Ruth M Benca
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697, USA; Department of Neurobiology and Behavior, University of California, Irvine 92697, USA; Department of Psychiatry and Human Behavior, University of California, 1418 Biological Sciences 3, Irvine, CA 92697, USA
| | - Liv McMillan
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697, USA; Department of Neurobiology and Behavior, University of California, Irvine 92697, USA
| | - John T Janecek
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697, USA; Department of Neurobiology and Behavior, University of California, Irvine 92697, USA
| | - Michael A Yassa
- Center for the Neurobiology of Learning and Memory, University of California, Irvine 92697, USA; Department of Neurobiology and Behavior, University of California, Irvine 92697, USA; Department of Psychiatry and Human Behavior, University of California, 1418 Biological Sciences 3, Irvine, CA 92697, USA.
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11
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Kark SM, Adams JG, Sathishkumar M, Granger SJ, McMillan L, Baram TZ, Yassa MA. Why do mothers never stop grieving for their deceased children? Enduring alterations of brain connectivity and function. Front Hum Neurosci 2022; 16:925242. [PMID: 36118972 PMCID: PMC9478601 DOI: 10.3389/fnhum.2022.925242] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 08/02/2022] [Indexed: 11/13/2022] Open
Abstract
A child's death is a profound loss for mothers and affects hundreds of thousands of women. Mothers report inconsolable and progressive grief that is distinct from depression and impacts daily emotions and functions. The brain mechanisms responsible for this relatively common and profound mental health problem are unclear, hampering its clinical recognition and care. In an initial exploration of this condition, we used resting state functional MRI (fMRI) scans to examine functional connectivity in key circuits, and task-based fMRI to examine brain network activity in grieving mothers in response to pictures of their deceased child and as well as recognizable deceased celebrities and unfamiliar individuals. We compared nine mothers who had lost an adult child and aged-matched control mothers with a living child of a similar age. Additionally, we collected diffusion imaging scans to probe structural connectivity and complemented the imaging studies with neuropsychological assessments. Increased functional activation in Ventral Attention/Salience Networks accompanied by a reduced activation in the medial prefrontal cortex in response to the deceased child's picture robustly distinguished the grieving mothers from controls. Heightened resting-state functional connectivity between the paraventricular thalamic nucleus (PVT) and the amygdala distinguished the grieving mothers from the controls and correlated with subjective grief severity. Structurally, maternal grief and its severity were associated with alterations in corticolimbic white matter tracts. Finally, grieving mothers performed worse than controls on neuropsychological tests of learning, memory, and executive function, linked with grief severity. Reduced activation in cortical regions inhibiting emotions and changes in the PVT circuitry-a region involved in long-term emotional memories and decision making under conflict-distinguish grieving mothers from controls. Notably, the magnitude of neurobiological changes correlates with the subjective severity of grief. Together, these new discoveries delineate a prevalent and under-recognized mental health syndrome and chart a path for its appreciation and care.
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Affiliation(s)
- Sarah M Kark
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States.,Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
| | - Joren G Adams
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States.,Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
| | - Mithra Sathishkumar
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States.,Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
| | - Steven J Granger
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States.,Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
| | - Liv McMillan
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States.,Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States
| | - Tallie Z Baram
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States.,Department of Pediatrics, University of California, Irvine, Irvine, CA, United States.,Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, CA, United States
| | - Michael A Yassa
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, Irvine, CA, United States.,Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, United States.,Department of Anatomy and Neurobiology, University of California, Irvine, Irvine, CA, United States
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12
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Upadhayay HR, Granger SJ, Collins AL. Dynamics of fluvial hydro-sedimentological, nutrient, particulate organic matter and effective particle size responses during the U.K. extreme wet winter of 2019–2020. Sci Total Environ 2021; 774:145722. [PMCID: PMC8073540 DOI: 10.1016/j.scitotenv.2021.145722] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2020] [Revised: 01/21/2021] [Accepted: 02/04/2021] [Indexed: 06/14/2023]
Abstract
The floc size distribution of suspended sediment is a critical driver for in-channel sedimentation and sediment-associated contaminant and nutrient transfer and fate in river catchments. Real-time, in situ, floc size characterisation is possible using available technology but, to date, limited high resolution floc data have been published for fluvial systems draining upland extensive grassland catchments. To that end, suspended sediment floc size distribution and turbidity were characterised at 15-minute intervals using Laser In-Situ Scattering and Transmissometry (LISST) diffraction and a YSI turbidity sonde for six storm events in the upper River Taw (15 km2) catchment in SW England. Maximum event discharges (Q) ranged between 4.3 and 20.0 m3 s−1, with clockwise hysteretic responses (HI = 0.18–0.48) of total suspended solid concentrations (TSS) and Q. The sediment flushing index was highest in the early autumn (0.93) and storm event TSS fluxes varied from 0.04 to 2.9 t km−2. This suggests a change in sources or composition of sediment during higher Q and highly variable patterns of sediment flux from event-to-event. The proportion of particulate organic matter (POM) to TSS was highly variable (5–89%) and did not increase with Q, indicating POM source limitation. The fine-grained tail (D10 and D16) of the floc size distributions decreased during hydrograph rising limbs, with the finest floc sizes associated with the highest TN and TP concentrations at peak Q. The results suggest that dynamic interactions between wet ground and extreme rainfall events can flush significant amounts of sediment from the relatively undisturbed extensive grassland upland catchment. We strongly encourage a sensors-based approach to reveal the spatio-temporal complexity of floc size and associated pollutant export during high Q generated by extreme rainfall since this can help to elucidate processes and mechanisms and generate high-resolution data for water quality modelling without significant user intervention. In situ flocs size and turbidity were studied in sequential high discharge events. Hydrographs characterised by clockwise hysteresis with a secondary sediment peak. Proportion of POM to TSS in the physical samples was highly variable (5–89%). Fine (D10 and D16) floc size diameter was lowest during peak discharges. Floc size exerted less influence on TP and TN concentrations.
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13
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Granger SJ, Leal SL, Larson MS, Janecek JT, McMillan L, Stern H, Yassa MA. Integrity of the uncinate fasciculus is associated with emotional pattern separation-related fMRI signals in the hippocampal dentate and CA3. Neurobiol Learn Mem 2020; 177:107359. [PMID: 33285317 DOI: 10.1016/j.nlm.2020.107359] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 11/25/2020] [Accepted: 12/02/2020] [Indexed: 11/26/2022]
Abstract
Alterations in white matter integrity have been demonstrated in a number of psychiatric disorders involving emotional disruptions. One such pathway - the uncinate fasciculus - connects the orbitofrontal cortex (OFC) to the medial temporal lobes (MTL) and has been associated with early life adversity, maltreatment, anxiety, and depression. While it is purported to play a role in episodic memory and discrimination, its exact function remains poorly understood. We have previously described the role of the amygdala and dentate (DG)/CA3 fields of the hippocampus in the mnemonic discrimination of emotional experiences (i.e. emotional pattern separation). However, how this computation may be modulated by connectivity with the orbitofrontal cortex remains unknown. Here we asked if the uncinate fasciculus plays a role in influencing MTL subregional activity during emotional pattern separation. By combining diffusion imaging with high-resolution fMRI, we found that reduced integrity of the UF is related to elevated BOLD fMRI activation of the DG/CA3 subregions of the hippocampus during emotional lure discrimination. We additionally report that higher levels of DG/CA3 activity are associated with poorer memory performance, suggesting that greater activation in this network (possibly driven by CA3 recurrent collaterals) is associated with memory errors. Based on this work we suggest that the UF is one pathway that may allow the OFC to exert control on this network and improve discrimination of emotional experiences, although further work is necessary to fully evaluate this possibility. This work provides novel insight into the role of prefrontal interactions with the MTL, particularly in the context of emotional memory.
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Affiliation(s)
- Steven J Granger
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, United States; Department of Neurobiology and Behavior, University of California, Irvine, United States
| | - Stephanie L Leal
- Department of Psychological Sciences, Rice University, Houston, TX, United States
| | - Myra Saraí Larson
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, United States; Department of Neurobiology and Behavior, University of California, Irvine, United States
| | - John T Janecek
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, United States; Department of Neurobiology and Behavior, University of California, Irvine, United States
| | - Liv McMillan
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, United States; Department of Neurobiology and Behavior, University of California, Irvine, United States
| | - Hal Stern
- Department of Statistics, University of California, Irvine, United States
| | - Michael A Yassa
- Center for the Neurobiology of Learning and Memory, University of California, Irvine, United States; Department of Neurobiology and Behavior, University of California, Irvine, United States.
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14
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Pfahler V, Bielnicka A, Smith AC, Granger SJ, Blackwell MS, Turner BL. A rapid ammonium fluoride method to determine the oxygen isotope ratio of available phosphorus in tropical soils. Rapid Commun Mass Spectrom 2020; 34:e8647. [PMID: 31671472 PMCID: PMC7064897 DOI: 10.1002/rcm.8647] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 10/25/2019] [Accepted: 10/28/2019] [Indexed: 06/10/2023]
Abstract
RATIONALE The isotopic composition of oxygen bound to phosphorus (δ18 OP value) offers an opportunity to gain insight into P cycling mechanisms. However, there is little information for tropical forest soils, which presents a challenge for δ18 OP measurements due to low available P concentrations. Here we report the use of a rapid ammonium fluoride extraction method (Bray-1) as an alternative to the widely used anion-exchange membrane (AEM) method for quantification of δ18 OP values of available P in tropical forest soils. METHODS We compared P concentrations and δ18 OP values of available and microbial P determined by AEM and Bray-1 extraction for a series of tropical forest soils from Panama spanning a steep P gradient. This involved an assessment of the influence of extraction conditions, including temperature, extraction time, fumigation time and solution-to-soil ratio, on P concentrations and isotope ratios. RESULTS Depending on the extraction conditions, Bray-1 P concentrations ranged from 0.2 to 66.3 mg P kg-1 across the soils. Extraction time and temperature had only minor effects on Bray-1 P, but concentrations increased markedly as the solution-to-soil ratio increased. In contrast, extraction conditions did not affect Bray-1 δ18 OP values, indicating that Bray-1 provides a robust measure of the isotopic composition of available soil P. For a relatively high P soil, available and fumigation-released (microbial) δ18 OP values determined by Bray-1 extraction (20‰ and 16‰, respectively) were higher than those determined by the AEM method (18‰ and 12‰, respectively), which we attribute to slightly different P pools extracted by the two methods and/or differences resulting from the longer extraction time needed for the AEM method. CONCLUSIONS The short extraction time, insensitivity to extraction conditions and smaller mass of soil required to extract sufficient P for isotopic analysis make Bray-1extraction a suitable alternative to the AEM method for the determination of δ18 OP values of available P in tropical soils.
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Affiliation(s)
- Verena Pfahler
- Sustainable Agriculture SciencesRothamsted ResearchNorth WykeOkehamptonEX20 2SBUK
- Smithsonian Tropical Research InstituteApartado 0843‐03092BalboaAnconRepublic of Panama
| | - Aleksandra Bielnicka
- Smithsonian Tropical Research InstituteApartado 0843‐03092BalboaAnconRepublic of Panama
| | - Andrew C. Smith
- NERC Isotope Geoscience LaboratoryBritish Geological SurveyNottinghamNG12 5GGUK
| | - Steven J. Granger
- Sustainable Agriculture SciencesRothamsted ResearchNorth WykeOkehamptonEX20 2SBUK
| | | | - Benjamin L. Turner
- Smithsonian Tropical Research InstituteApartado 0843‐03092BalboaAnconRepublic of Panama
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15
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Pfahler V, Macdonald A, Mead A, Smith AC, Tamburini F, Blackwell MSA, Granger SJ. Changes of oxygen isotope values of soil P pools associated with changes in soil pH. Sci Rep 2020; 10:2065. [PMID: 32034236 PMCID: PMC7005815 DOI: 10.1038/s41598-020-59103-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 01/20/2020] [Indexed: 12/05/2022] Open
Abstract
Field data about the effect of soil pH on phosphorus (P) cycling is limited. A promising tool to study P cycling under field conditions is the 18O:16O ratio of phosphate (δ18OP). In this study we investigate whether the δ18OP can be used to elucidate the effect of soil pH on P cycling in grasslands. Soils and plants were sampled from different fertilisation and lime treatments of the Park Grass long term experiment at Rothamsted Research, UK. The soils were sequentially extracted to isolate different soil P pools, including available P and corresponding δ18OP values were determined. We did not observe changes in plant δ18OP value, but soil P δ18OP values changed, and lower δ18OP values were associated with higher soil pH values. At sites where P was not limiting, available P δ18OP increased by up to 3‰ when lime was applied. We show that the δ18OP method is a useful tool to investigate the effect of pH on soil P cycling under field conditions as it highlights that different soil processes must govern P availability as pH shifts. The next challenge is now to identify these underlying processes, enabling better management of soil P at different pH.
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Affiliation(s)
- Verena Pfahler
- Rothamsted Research, Sustainable Agriculture Sciences North Wyke, Okehampton, Devon, EX20 2SB, UK.
| | - Andy Macdonald
- Rothamsted Research, Sustainable Agriculture Sciences Harpenden, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Andrew Mead
- Rothamsted Research, Computational and Analytical Sciences, Harpenden, Hertfordshire, AL5 2JQ, UK
| | - Andrew C Smith
- NERC Isotope Geoscience Laboratory, British Geological Survey, Nottingham, NG12 5GG, UK
| | - Federica Tamburini
- Department of Environmental System Sciences, ETH Zurich, Eschikon 33, 8315, Lindau, Switzerland
| | - Martin S A Blackwell
- Rothamsted Research, Sustainable Agriculture Sciences North Wyke, Okehampton, Devon, EX20 2SB, UK
| | - Steven J Granger
- Rothamsted Research, Sustainable Agriculture Sciences North Wyke, Okehampton, Devon, EX20 2SB, UK
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16
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Granger SJ, Yang Y, Pfahler V, Hodgson C, Smith AC, Le Cocq K, Collins AL, Blackwell MSA, Howden NJK. The stable oxygen isotope ratio of resin extractable phosphate derived from fresh cattle faeces. Rapid Commun Mass Spectrom 2018; 32:703-710. [PMID: 29490108 PMCID: PMC5900733 DOI: 10.1002/rcm.8092] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 02/16/2018] [Accepted: 02/16/2018] [Indexed: 05/31/2023]
Abstract
RATIONALE Phosphorus losses from agriculture pose an environmental threat to watercourses. A new approach using the stable oxygen isotope ratio of oxygen in phosphate (δ18 OPO4 value) may help elucidate some phosphorus sources and cycling. Accurately determined and isotopically distinct source values are essential for this process. The δ18 OPO4 values of animal wastes have, up to now, received little attention. METHODS Phosphate (PO4 ) was extracted from cattle faeces using anion resins and the contribution of microbial PO4 was assessed. The δ18 OPO4 value of the extracted PO4 was measured by precipitating silver phosphate and subsequent analysis on a thermal conversion elemental analyser at 1400°C, with the resultant carbon monoxide being mixed with a helium carrier gas passed through a gas chromatography (GC) column into a mass spectrometer. Faecal water oxygen isotope ratios (δ18 OH2O values) were determined on a dual-inlet mass spectrometer through a process of headspace carbon dioxide equilibration with water samples. RESULTS Microbiological results indicated that much of the extracted PO4 was not derived directly from the gut fauna lysed during the extraction of PO4 from the faeces. Assuming that the faecal δ18 OH2O values represented cattle body water, the predicted pyrophosphatase equilibrium δ18 OPO4 (Eδ18 OPO4 ) values ranged between +17.9 and +19.9‰, while using groundwater δ18 OH2O values gave a range of +13.1 to +14.0‰. The faecal δ18 OPO4 values ranged between +13.2 and +15.3‰. CONCLUSIONS The fresh faecal δ18 OPO4 values were equivalent to those reported elsewhere for agricultural animal slurry. However, they were different from the Eδ18 OPO4 value calculated from the faecal δ18 OH2O value. Our results indicate that slurry PO4 is, in the main, derived from animal faeces although an explanation for the observed value range could not be determined.
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Affiliation(s)
| | - Yuguo Yang
- Queen's School of EngineeringUniversity of BristolSenate House, Tyndall AvenueBristolBS8 1THUK
| | | | | | - Andrew C. Smith
- NERC Isotope Geoscience LaboratoryBritish Geological SurveyKeyworthNottinghamNG12 5GGUK
| | - Kate Le Cocq
- Rothamsted ResearchNorth WykeOkehamptonEX20 2SBUK
| | | | | | - Nicholas J. K. Howden
- Queen's School of EngineeringUniversity of BristolSenate House, Tyndall AvenueBristolBS8 1THUK
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17
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Granger SJ, Harris P, Peukert S, Guo R, Tamburini F, Blackwell MS, Howden NJ, McGrath S. Phosphate stable oxygen isotope variability within a temperate agricultural soil. Geoderma 2017; 285:64-75. [PMID: 28050050 PMCID: PMC5127558 DOI: 10.1016/j.geoderma.2016.09.020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Revised: 09/13/2016] [Accepted: 09/21/2016] [Indexed: 05/21/2023]
Abstract
In this study, we conduct a spatial analysis of soil total phosphorus (TP), acid extractable phosphate (PO4) and the stable oxygen (O) isotope ratio within the PO4 molecule (δ18OPO4 ) from an intensively managed agricultural grassland site. Total P in the soil was found to range from 736 to 1952 mg P kg- 1, of which between 12 and 48% was extractable using a 1 M HCl (HClPO4 ) solution with the two variables exhibiting a strong positive correlation. The δ18OPO4 of the extracted PO4 ranged from 17.0 to 21.6‰ with a mean of 18.8‰ (± 0.8). While the spatial variability of Total P has been researched at various scales, this is the first study to assess the variability of soil δ18OPO4 at a field-scale resolution. We investigate whether or not δ18OPO4 variability has any significant relationship with: (i) itself with respect to spatial autocorrelation effects; and (ii) HClPO4 , elevation and slope - both globally and locally. Results indicate that δ18OPO4 was not spatially autocorrelated; and that δ18OPO4 was only weakly related to HClPO4 , elevation and slope, when considering the study field as a whole. Interestingly, the latter relationships appear to vary in strength locally. In particular, the δ18OPO4 to HClPO4 relationship may depend on the underlying soil class and/or on different field managements that had operated across an historical north-south field division of the study field, a division that had been removed four years prior to this study.
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Affiliation(s)
- Steven J. Granger
- Rothamsted Research, North Wyke, Okehampton, Devon EX20 2SB, United Kingdom
- Corresponding author.
| | - Paul Harris
- Rothamsted Research, North Wyke, Okehampton, Devon EX20 2SB, United Kingdom
| | - Sabine Peukert
- Rothamsted Research, North Wyke, Okehampton, Devon EX20 2SB, United Kingdom
| | - Rongrong Guo
- Queen's School of Engineering, University of Bristol, Senate House, Tyndall Avenue, Bristol BS8 1TH, United Kingdom
| | - Federica Tamburini
- Institute of Agricultural Sciences, ETH Zurich, Research Station Eschikon 33, 8315 Lindau, Switzerland
| | | | - Nicholas J.K. Howden
- Queen's School of Engineering, University of Bristol, Senate House, Tyndall Avenue, Bristol BS8 1TH, United Kingdom
| | - Steve McGrath
- Rothamsted Research, West Common, Harpenden, Hertfordshire, AL5 2JQ, United Kingdom
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18
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Granger SJ, Heaton THE, Pfahler V, Blackwell MSA, Yuan H, Collins AL. The oxygen isotopic composition of phosphate in river water and its potential sources in the Upper River Taw catchment, UK. Sci Total Environ 2017; 574:680-690. [PMID: 27697742 DOI: 10.1016/j.scitotenv.2016.09.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2016] [Revised: 08/23/2016] [Accepted: 09/01/2016] [Indexed: 06/06/2023]
Abstract
The need to reduce both point and diffuse phosphorus pollution to aquatic ecosystems is widely recognised and in order to achieve this, identification of the different pollutant sources is essential. Recently, a stable isotope approach using oxygen isotopes within phosphate (δ18OPO4) has been used in phosphorus source tracing studies. This approach was applied in a one-off survey in September 2013 to the River Taw catchment in south-west England where elevated levels of phosphate have been reported. River water δ18OPO4 along the main channel varied little, ranging from +17.1 to +18.8‰. This was no >0.3‰ different to that of the isotopic equilibrium with water (Eδ18OPO4). The δ18OPO4 in the tributaries was more variable (+17.1 to +18.8‰), but only deviated from Eδ18OPO4 by between 0.4 and 0.9‰. Several potential phosphate sources within the catchment were sampled and most had a narrow range of δ18OPO4 values similar to that of river Eδ18OPO4. Discharge from two waste water treatment plants had different and distinct δ18OPO4 from one another ranging between +16.4 and +19.6‰ and similar values to that of a dairy factory final effluent (+16.5 to +17.8‰), mains tap water (+17.8 to +18.4‰), and that of the phosphate extracted from river channel bed sediment (+16.7 to +17.6‰). Inorganic fertilizers had a wide range of values (+13.3 to +25.9‰) while stored animal wastes were consistently lower (+12.0 to +15.0‰) than most other sources and Eδ18OPO4. The distinct signals from the waste water treatment plants were lost within the river over a short distance suggesting that rapid microbial cycling of phosphate was occurring, because microbial cycling shifts the isotopic signal towards Eδ18OPO4. This study has added to the global inventory of phosphate source δ18OPO4 values, but also demonstrated the limitations of this approach to identifying phosphate sources, especially at times when microbial cycling is high.
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Affiliation(s)
- Steven J Granger
- Rothamsted Research, North Wyke, Okehampton, Devon EX20 2SB, UK.
| | - Tim H E Heaton
- NERC Isotope Geoscience Laboratory, British Geological Survey, Nottingham NG12 5GG, UK
| | - Verena Pfahler
- Rothamsted Research, North Wyke, Okehampton, Devon EX20 2SB, UK
| | | | - Huimin Yuan
- College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan West Road, Haidian, Beijing 100193, China
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Hiroi R, Quihuis AM, Lavery CN, Granger SJ, Weyrich G, Bimonte-Nelson HA. Sex-specific effects of chronic antidepressant treatment in middle-aged rats: impact of citalopram on cognition and depressive-like behaviors. Maturitas 2015. [DOI: 10.1016/j.maturitas.2015.02.177] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Old GH, Naden PS, Granger SJ, Bilotta GS, Brazier RE, Macleod CJA, Krueger T, Bol R, Hawkins JMB, Haygarth P, Freer J. A novel application of natural fluorescence to understand the sources and transport pathways of pollutants from livestock farming in small headwater catchments. Sci Total Environ 2012; 417-418:169-182. [PMID: 22277148 DOI: 10.1016/j.scitotenv.2011.12.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2011] [Revised: 11/28/2011] [Accepted: 12/03/2011] [Indexed: 05/31/2023]
Abstract
This paper demonstrates the application of a low-cost and rapid natural fluorescence technique for tracing and quantifying the transport of pollutants from livestock farming through a small headwater catchment. Fluorescence intensities of Dissolved Organic Matter (DOM) present in different pollutant sources and drainage waters in the Den Brook catchment (Devon, UK) were monitored through storm events occurring between January 2007 and June 2008. Contrasting fluorescence signals from different sources confirmed the technique's usefulness as a tracer of pollutants from livestock farming. Changes in fluorescence intensities of drainage waters throughout storm events were used to assess the dynamics of key pollutant sources. The farmyard area of the catchment studied was shown to contribute polluted runoff at the onset of storm events in response to only small amounts of rain, when flows in the Den Brook first-order channel were low. The application of slurry to a field within the catchment did not elevate the fluorescence of drainage waters during storm events suggesting that when slurry is applied to undrained fields the fluorescent DOM may become quickly adsorbed onto soil particles and/or immobilised through bacterial breakdown. Fluorescence intensities of drainage waters were successfully combined with discharge data in a two component mixing model to estimate pollutant fluxes from key sources during the January 2007 storm event. The farmyard was shown to be the dominant source of tryptophan-like material, contributing 61-81% of the total event flux at the catchment outlet. High spatial and temporal resolution measurements of fluorescence, possibly using novel in-situ fluorimeters, may thus have great potential in quickly identifying and quantifying the presence, dynamics and sources of pollutants from livestock farming in catchments.
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Affiliation(s)
- G H Old
- Centre for Ecology and Hydrology, Wallingford, Oxfordshire, UK.
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Granger SJ, Bol R, Meier-Augenstein W, Leng MJ, Kemp HF, Heaton THE, White SM. The hydrological response of heavy clay grassland soils to rainfall in south-west England using delta2H. Rapid Commun Mass Spectrom 2010; 24:475-482. [PMID: 20127906 DOI: 10.1002/rcm.4281] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Stable isotopes of water have been previously used in catchment studies to separate rain-event water from pre-event groundwater. However, there are a lack of studies at the smaller scale looking at the separation of event water from pre-event water. This is particularly relevant for heavy clay soil systems through which the movement of water is uncertain but is thought to be rainwater-dominated. The data presented here were collected at a rural site in the south-west of England. The historic rainfall at the site was isotopically varied but similar to the global meteoric water line, with annual weighted means of -37 per thousand for delta(2)H and -5.7 per thousand for delta(18)O and with no seasonal variation. Drainage was sampled from the inter-flow (surface runoff + lateral through-flow) and drain-flow (55 cm deep mole drains) pathways of two 1 ha lysimeters during two rainfall events, which had delta(2)H values of -68 per thousand and -92 per thousand, respectively. The delta(2)H values of the lysimeter drainage water suggest that there was no contribution of event water during the first, small discharge (Q) event; however, the second larger event did show isotopic variation in delta(2)H values negatively related to Q indicating that rainwater was contributing to Q. A hydrograph separation indicated that only 49-58% of the inter-flow and 18-25% of the drain-flow consisted of event water. This was surprising given that these soil types are considered retentive of soil water. More work is needed on heavy clay soils to understand better the nature of water movement from these systems.
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Dungait JAJ, Bol R, Lopez-Capel E, Bull ID, Chadwick D, Amelung W, Granger SJ, Manning DAC, Evershed RP. Applications of stable isotope ratio mass spectrometry in cattle dung carbon cycling studies. Rapid Commun Mass Spectrom 2010; 24:495-500. [PMID: 20112271 DOI: 10.1002/rcm.4332] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Understanding the fate of dung carbon (C) in soils is challenging due to the ubiquitous presence of the plant-derived organic matter (OM), the source material from which both dung-derived OM and soil organic matter (SOM) predominantly originate. A better understanding of the fate of specific components of this substantial source of OM, and thereby its contribution to C cycling in terrestrial ecosystems, can only be achieved through the use of labelled dung treatments. In this short review, we consider analytical approaches using bulk and compound-specific stable carbon isotope analysis that have been utilised to explore the fate of dung-derived C in soils. Bulk stable carbon isotope analyses are now used routinely to explore OM matter cycling in soils, and have shown that up to 20% of applied dung C may be incorporated into the surface soil horizons several weeks after application, with up to 8% remaining in the soil profile after one year. However, whole soil delta(13)C values represent the average of a wide range of organic components with varying delta(13)C values and mean residence times in soils. Several stable (13)C isotope ratio mass spectrometric methods have been developed to qualify and quantify different fractions of OM in soils and other complex matrices. In particular, thermogravimetry-differential scanning calorimetry-isotope ratio mass spectrometry (TG-DSC-IRMS) and gas chromatography-combustion-IRMS (GC-C-IRMS) analyses have been applied to determine the incorporation and turnover of polymeric plant cell wall materials from C(4) dung into C(3) grassland soils using natural abundance (13)C isotope labelling. Both approaches showed that fluxes of C derived from polysaccharides, i.e. as cellulose or monosaccharide components, were more similar to the behaviour of bulk dung C in soil than lignin. However, lignin and its 4-hydroxypropanoid monomers were unexpectedly dynamic in soil. These findings provide further evidence for emerging themes in biogeochemical investigations of soil OM dynamics that challenge perceived concepts of recalcitrance of C pools in soils, which may have profound implications for the assessment of the potential of agricultural soils to influence terrestrial C sinks.
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Granger SJ, Bol R, Dixon L, Naden PS, Old GH, Marsh JK, Bilotta G, Brazier R, White SM, Haygarth PM. Assessing multiple novel tracers to improve the understanding of the contribution of agricultural farm waste to diffuse water pollution. ACTA ACUST UNITED AC 2010; 12:1159-69. [DOI: 10.1039/b915929k] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Granger SJ, Heaton THE, Bol R, Bilotta GS, Butler P, Haygarth PM, Owens PN. Using delta15N and delta18O to evaluate the sources and pathways of NO3- in rainfall event discharge from drained agricultural grassland lysimeters at high temporal resolutions. Rapid Commun Mass Spectrom 2008; 22:1681-1689. [PMID: 18438978 DOI: 10.1002/rcm.3505] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The origin of NO(3) (-) yielded in drainage from agricultural grasslands is of environmental significance and has three potential sources; (i) soil organic mater (SOM), (ii) recent agricultural amendments, and (iii) atmospheric inputs. The variation in delta(15)N-NO(3) (-) and delta(18)O-NO(3) (-) was measured from the 'inter-flow' and 'drain-flow' of two 1 ha drained lysimeter plots, one of which had received an application of 21 m(3) of NH(4) (+)-N-rich agricultural slurry, during two rainfall events. Drainage started to occur 1 month after the application of slurry. The concentrations of NO(3) (-)-N from the two lysimeters were comparable; an initial flush of NO(3) (-)-N occurred at the onset of drainage from both lysimeters before levels quickly dropped to <1 mg NO(3) (-)-N L(-1). The isotopic signature of the delta(15)N-NO(3) (-) and delta(18)O-NO(3) (-) during the first two rainfall events showed a great deal of variation over short time-periods from both lysimeters. Isotopic variation of delta(15)N-NO(3) (-) during rainfall events ranged between -1.6 to +5.2 per thousand and +0.4 to +11.1 per thousand from the inter-flow and drain-flow, respectively. Variation in the delta(18)O-NO(3) (-) ranged from +2.0 to +7.8 per thousand and from +3.3 to +8.4 per thousand. No significant relationships between the delta(15)N-NO(3) (-) or delta(18)O-NO(3) (-) and flow rate were observed in most cases although delta(18)O-NO(3) (-) values indicated a positive relationship and delta(15)N-NO(3) (-) values a negative relationship with flow during event 2. Data from a bulked rainfall sample when compared with the theoretical delta(18)O-NO(3) (-) for soil microbial NO(3) (-) indicated that the contribution of rainfall NO(3) (-) accounted for 8% of the NO(3) (-) in the lysimeter drainage at most. The calculated contribution of rainfall NO(3) (-) was not enough to account for the depletion in delta(15)N-NO(3) (-) values observed during the duration of the rainfall event 2. The relationship between delta(15)N-NO(3) (-) and delta(18)O-NO(3) (-) from the drain-flow indicated that denitrification was causing enrichment in the isotopes from this pathway. The presence of slurry seemed to cause a relative depletion in delta(18)O-NO(3) (-) in the inter-flow and delta(15)N-NO(3) (-) in the drain-flow compared with the zero-slurry lysimeter. This may have been caused by increased microbial nitrification stimulated by the presence of increased NH(4) (+)-N.
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Affiliation(s)
- Steven J Granger
- Institute of Grassland and Environmental Research, North Wyke, Okehampton EX20 2SB, UK.
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