Background Vegetation fire may change Phosphorus (P) cycling in terrestrial ecosystems through converting biomass into fire residues. Aim The aim of this study was to understand the chemistry and mobility of P in fire residues to help reveal P thermochemistry during biomass burning and post-fire P cycling. Methods A combination of sequential extraction, liquid 31P NMR and P K-edge XANES was used to obtain quantitative P speciation and explain P solubilisation behaviours of charcoal. Key results Despite varying diverse P species existing in raw biomass, only two P structural moieties – orthophosphate and pyrophosphate – were identified in charcoal. However, relative abundance of pyrophosphate differs greatly among charcoal samples from different biomass types, ranging between 0 and 40% of total extractable P. Although P K-edge XANES data indicates abundant soluble phosphate minerals, most P (70–90%) is likely occluded physically in the charcoal. The bicarbonate-extractable P (the Olsen-P) varies significantly and cannot be explained by surface P concentration or elemental stoichiometry alone. Conclusion and implications The results suggest the importance of starting biomass P speciation (i.e. molecular structure and complexation environment) and thermal conditions in controlling P speciation and availability in charcoal. The different P chemistry between charcoal and ash suggests the importance of fire types and severity in disturbing the P cycle.
This content will become publicly available on January 31, 2025
This study explores the advantages and limitations of shaped narrowband and broadband excitation pulses in EPR spectroscopy on spin-correlated radical pairs, including chirp out-of-phase ESEEM.
more » « less- Award ID(s):
- 2154627
- PAR ID:
- 10516620
- Publisher / Repository:
- RSC
- Date Published:
- Journal Name:
- Physical Chemistry Chemical Physics
- Volume:
- 26
- Issue:
- 5
- ISSN:
- 1463-9076
- Page Range / eLocation ID:
- 3842 to 3856
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
More Like this
-
more » « less
-
more » « less
Abstract Litter decomposition is a key ecological process that determines carbon (C) and nutrient cycling in terrestrial ecosystems. The initial concentrations of C and nutrients in litter play a critical role in this process, yet the global patterns of litter initial concentrations of C, nitrogen (N) and phosphorus (P) are poorly understood.
We employed machine learning with a global database to quantitatively assess the global patterns and drivers of leaf litter initial C, N and P concentrations, as well as their returning amounts (i.e. amounts returned to soils).
The medians of litter C, N and P concentrations were 46.7, 1.1, and 0.1%, respectively, and the medians of litter C, N and P returning amounts were 1.436, 0.038 and 0.004 Mg ha−1 year−1, respectively. Soil and climate emerged as the key predictors of leaf litter C, N and P concentrations. Predicted global maps showed that leaf litter N and P concentrations decreased with latitude, while C concentration exhibited an opposite pattern. Additionally, the returning amounts of leaf litter C, N and P all declined from the equator to the poles in both hemispheres.
Synthesis : Our results provide a quantitative assessment of the global concentrations and returning amounts of leaf litter C, N and P, which showed new light on the role of leaf litter in global C and nutrients cycling. -
more » « less
Abstract Vibrio parahaemolyticus is a Gram‐negative, halophilic bacterium and opportunistic pathogen of humans and shrimp. Investigating the mechanisms ofV. parahaemolyticus infection and the multifarious virulence factors it employs requires procedures for bacterial culture, genetic manipulation, and analysis of virulence phenotypes. Detailed protocols for growth assessment, generation of mutants, and phenotype assessment are included in this article. © 2020 Wiley Periodicals LLC.Basic Protocol 1 : Assessment of growth ofV. parahaemolyticus Alternate Protocol 1 : Assessment of growth ofV. parahaemolyticus using a plate readerBasic Protocol 2 : Swimming/swarming motility assayBasic Protocol 3 : Genetic manipulationAlternate Protocol 2 : Natural transformationBasic Protocol 4 : Secretion assay and sample preparation for mass spectrometry analysisBasic Protocol 5 : Invasion assay (gentamicin protection assay)Basic Protocol 6 : Immunofluorescence detection of intracellularV. parahaemolyticus Basic Protocol 7 : Cytotoxicity assay for T3SS2 -
more » « less
Abstract In vitro culture models of the blood‐brain barrier (BBB) provide a useful platform to test the mechanisms of cellular infiltration and pathogen dissemination into the central nervous system (CNS). We present an in vitro mouse model of the BBB to test
Mycobacterium tuberculosis (Mtb) dissemination across brain endothelial cells. One‐third of the global population is infected with Mtb, and in 1%‐2% of cases bacteria invade the CNS through a largely unknown process. The “Trojan horse” theory supports the role of a cellular carrier that engulfs bacteria and carries them to the brain without being recognized. We present for the first time a protocol for an in vitro BBB‐granuloma model that supports the Trojan horse mechanism of Mtb dissemination into the CNS. Handling of bacterial cultures, in vivo and in vitro infections, isolation of primary astroglial and endothelial cells, and assembly of the in vitro BBB model is presented. These techniques can be used to analyze the interaction of adaptive and innate immune system cells with brain endothelial cells, cellular transmigration, BBB morphological and functional changes, and methods of bacterial dissemination. © 2020 Wiley Periodicals LLC.Basic Protocol 1 : Isolation of primary mouse brain astrocytes and endothelial cellsBasic Protocol 2 : Isolation of primary mouse bone marrow–derived dendritic cellsSupport Protocol 1 : Validation of dendritic cell purity by flow cytometryBasic Protocol 3 : Isolation of primary mouse peripheral blood mononuclear cellsSupport Protocol 2 : Isolation of primary mouse spleen cellsSupport Protocol 3 : Purification and validation of CD4+ T cells from PBMCs and spleen cellsBasic Protocol 4 : Isolation of liver granuloma supernatant and determination of organ loadSupport Protocol 4 : In vivo and in vitro infection with mycobacteriaBasic Protocol 5 : Assembly of the BBB co‐culture modelBasic Protocol 6 : Assembly of the combined in vitro granuloma and BBB model -
more » « less
Abstract FlyBase (
www.flybase.org ) is the primary online database of genetic, genomic, and functional information aboutDrosophila melanogaster . The long and rich history ofDrosophila research, combined with recent surges in genomic‐scale and high‐throughput technologies, means that FlyBase now houses a huge quantity of data. Researchers need to be able to query these data rapidly and intuitively, and the QuickSearch tool has been designed to meet these needs. This tool is conveniently located on the FlyBase homepage and is organized into a series of simple tabbed interfaces that cover the major data and annotation classes within the database. This article describes the functionality of all aspects of the QuickSearch tool. With this knowledge, FlyBase users will be equipped to take full advantage of all QuickSearch features and thereby gain improved access to data relevant to their research. © 2023 The Authors. Current Protocols published by Wiley Periodicals LLC.Basic Protocol 1 : Using the “Search FlyBase” tab of QuickSearchBasic Protocol 2 : Using the “Data Class” tab of QuickSearchBasic Protocol 3 : Using the “References” tab of QuickSearchBasic Protocol 4 : Using the “Gene Groups” tab of QuickSearchBasic Protocol 5 : Using the “Pathways” tab of QuickSearchBasic Protocol 6 : Using the “GO” tab of QuickSearchBasic Protocol 7 : Using the “Protein Domains” tab of QuickSearchBasic Protocol 8 : Using the “Expression” tab of QuickSearchBasic Protocol 9 : Using the “GAL4 etc” tab of QuickSearchBasic Protocol 10 : Using the “Phenotype” tab of QuickSearchBasic Protocol 11 : Using the “Human Disease” tab of QuickSearchBasic Protocol 12 : Using the “Homologs” tab of QuickSearchSupport Protocol 1 : Managing FlyBase hit lists
