Natural carbon stores we must not lose now mapped

Dissimilatory phosphite oxidation (DPO), a microbial metabolism by which phosphite (HPO32−) is oxidized to phosphate (PO43−), is the most energetically favorable chemotrophic electron-donating process known. Only one DPO organism has been described to date, and little is known about the environmental relevance of this metabolism. In this study, we used 16S rRNA gene community analysis and genome-resolved metagenomics to characterize anaerobic wastewater treatment sludge enrichments performing DPO coupled to CO2reduction. We identified an uncultivated DPO bacterium,CandidatusPhosphitivorax (Ca.P.) anaerolimi strain Phox-21, that belongs to candidate order GW-28 within theDeltaproteobacteria, which has no known cultured isolates. Genes for phosphite oxidation and for CO2reduction to formate were found in the genome ofCa.P. anaerolimi, but it appears to lack any of the known natural carbon fixation pathways. These observations led us to propose a metabolic model for autotrophic growth byCa.P. anaerolimi whereby DPO drives CO2reduction to formate, which is then assimilated into biomass via the reductive glycine pathway.

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Urban sacred grove forests are potential carbon stores: A case study from Sikkim Himalaya

Environmental Challenges ◽

10.1016/j.envc.2021.100072 ◽

2021 ◽

Vol 4 ◽

pp. 100072

Author(s):

N. Bijayalaxmi Devi ◽

Nima T. Lepcha ◽

Siddarth S. Mahalik ◽

Denish Dutta ◽

Benrithung L. Tsanglao

Keyword(s):

Sacred Grove ◽

Sikkim Himalaya ◽

Carbon Stores ◽

Potential Carbon

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Quantifying carbon stores and decomposition in dead wood: A review

Forest Ecology and Management ◽

10.1016/j.foreco.2015.04.033 ◽

2015 ◽

Vol 350 ◽

pp. 107-128 ◽

Cited By ~ 85

Author(s):

Matthew B. Russell ◽

Shawn Fraver ◽

Tuomas Aakala ◽

Jeffrey H. Gove ◽

Christopher W. Woodall ◽

...

Keyword(s):

Dead Wood ◽

Carbon Stores

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Simulating natural carbon sequestration in the Southern Ocean: on uncertainties associated with eddy parameterizations and iron deposition

Biogeosciences ◽

10.5194/bg-14-1561-2017 ◽

2017 ◽

Vol 14 (6) ◽

pp. 1561-1576 ◽

Cited By ~ 3

Author(s):

Heiner Dietze ◽

Julia Getzlaff ◽

Ulrike Löptien

Keyword(s):

Carbon Sequestration ◽

Southern Ocean ◽

Ocean Circulation ◽

Spatial Scales ◽

Carbon Uptake ◽

Comprehensive Understanding ◽

Biogeochemical Models ◽

Anthropogenic Carbon ◽

Natural Carbon ◽

Oceanic Carbon

Abstract. The Southern Ocean is a major sink for anthropogenic carbon. Yet, there is no quantitative consensus about how this sink will change when surface winds increase (as they are anticipated to do). Among the tools employed to quantify carbon uptake are global coupled ocean-circulation–biogeochemical models. Because of computational limitations these models still fail to resolve potentially important spatial scales. Instead, processes on these scales are parameterized. There is concern that deficiencies in these so-called eddy parameterizations might imprint incorrect sensitivities of projected oceanic carbon uptake. Here, we compare natural carbon uptake in the Southern Ocean simulated with contemporary eddy parameterizations. We find that very differing parameterizations yield surprisingly similar oceanic carbon in response to strengthening winds. In contrast, we find (in an additional simulation) that the carbon uptake does differ substantially when the supply of bioavailable iron is altered within its envelope of uncertainty. We conclude that a more comprehensive understanding of bioavailable iron dynamics will substantially reduce the uncertainty of model-based projections of oceanic carbon uptake.

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Recent changes in the global and regional carbon cycle: analysis of first-order diagnostics

Biogeosciences ◽

10.5194/bg-12-835-2015 ◽

2015 ◽

Vol 12 (3) ◽

pp. 835-844 ◽

Cited By ~ 6

Author(s):

P. J. Rayner ◽

A. Stavert ◽

M. Scholze ◽

A. Ahlström ◽

C. E. Allison ◽

...

Keyword(s):

Carbon Cycle ◽

Linear Response ◽

Anthropogenic Emissions ◽

Seasonal Patterns ◽

Atmospheric Concentration ◽

First Order ◽

Northern Summer ◽

Data Points ◽

Natural Carbon ◽

The Tropics

Abstract. We analyse global and regional changes in CO2 fluxes using two simple models, an airborne fraction of anthropogenic emissions and a linear relationship with CO2 concentrations. We show that both models are able to fit the non-anthropogenic (hereafter natural) flux over the length of the atmospheric concentration record. Analysis of the linear model (including its uncertainties) suggests no significant decrease in the response of the natural carbon cycle. Recent data points rather to an increase. We apply the same linear diagnostic to fluxes from atmospheric inversions. Flux responses show clear regional and seasonal patterns driven by terrestrial uptake in the northern summer. Ocean fluxes show little or no linear response. Terrestrial models show clear responses, agreeing globally with the inversion responses, however the spatial structure is quite different, with dominant responses in the tropics rather than the northern extratropics.

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The potential for mobile demersal fishing to reduce carbon storage and sequestration in seabed sediments

10.1101/2021.07.07.450307 ◽

2021 ◽

Author(s):

Graham Epstein ◽

Julie P Hawkins ◽

Catrin R Norris ◽

Callum M Roberts

Keyword(s):

Sediment Resuspension ◽

Order Estimate ◽

Sediment Type ◽

Seabed Sediment ◽

Flocculent Material ◽

Sediment Carbon ◽

Carbon Stores ◽

Seabed Sediments ◽

Fish And Shellfish ◽

The Impact

Subtidal marine sediments are one of the planet's primary carbon stores and strongly influence the oceanic sink for atmospheric CO2. By far the most pervasive human activity occurring on the seabed is bottom trawling and dredging for fish and shellfish. A global first-order estimate suggested mobile demersal fishing activities may cause 160-400 Mt of organic carbon (OC) to be remineralised annually from seabed sediment carbon stores. There are, however, many uncertainties in this calculation. Here, we discuss the potential drivers of change in seabed OC stores due to mobile demersal fishing activities and conduct a systematic review, synthesising studies where this interaction has been directly investigated. Mobile demersal fishing would be expected to reduce OC in seabed stores, albeit with site-specific variability. Reductions would occur due to lower production of flora and fauna, the loss of fine flocculent material, increased sediment resuspension, mixing and transport, and increased oxygen exposure. This would be offset to some extent by reduced faunal bioturbation and respiration, increased off-shelf transport and increases in primary production from the resuspension of nutrients. Studies which directly investigated the impact of demersal fishing on OC stocks had mixed results. A finding of no significant effect was reported in 51% of 59 experimental contrasts; 41% reported lower OC due to fishing activities, with 8% reporting higher OC. In relation to remineralisation rates within the seabed, 14 experimental contrasts reported that demersal fishing activities decreased remineralisation, with four reporting higher remineralisation rates. The direction of effects was related to sediment type, impact duration, study design and local hydrography. More evidence is urgently needed to accurately quantify the impact of anthropogenic physical disturbance on seabed carbon in different environmental settings, and incorporate full evidence-based carbon considerations into global seabed management.

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Natural Carbon Nanodots: Toxicity Assessment and Theranostic Biological Application

Pharmaceutics ◽

10.3390/pharmaceutics13111874 ◽

2021 ◽

Vol 13 (11) ◽

pp. 1874

Author(s):

Ming-Hsien Chan ◽

Bo-Gu Chen ◽

Loan Thi Ngo ◽

Wen-Tse Huang ◽

Chien-Hsiu Li ◽

...

Keyword(s):

Carbon Source ◽

Large Scale ◽

New Technologies ◽

Cell Damage ◽

Carbon Sources ◽

Diagnosis And Treatment ◽

Carbon Nanodots ◽

Biological Application ◽

Treatment Research ◽

Natural Carbon

This review outlines the methods for preparing carbon dots (CDs) from various natural resources to select the process to produce CDs with the best biological application efficacy. The oxidative activity of CDs mainly involves photo-induced cell damage and the destruction of biofilm matrices through the production of reactive oxygen species (ROS), thereby causing cell auto-apoptosis. Recent research has found that CDs derived from organic carbon sources can treat cancer cells as effectively as conventional drugs without causing damage to normal cells. CDs obtained by heating a natural carbon source inherit properties similar to the carbon source from which they are derived. Importantly, these characteristics can be exploited to perform non-invasive targeted therapy on human cancers, avoiding the harm caused to the human body by conventional treatments. CDs are attractive for large-scale clinical applications. Water, herbs, plants, and probiotics are ideal carbon-containing sources that can be used to synthesize therapeutic and diagnostic CDs that have become the focus of attention due to their excellent light stability, fluorescence, good biocompatibility, and low toxicity. They can be applied as biosensors, bioimaging, diagnosis, and treatment applications. These advantages make CDs attractive for large-scale clinical application, providing new technologies and methods for disease occurrence, diagnosis, and treatment research.

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Differential Cross Section Measurements of the $^{12}C(d,p_{1,2,3})^{13}C$ Reaction, in the Energy Range E$_{d,lab}$= 900-2000 keV, Suitable for NRA

HNPS Proceedings ◽

10.12681/hnps.2624 ◽

2020 ◽

Vol 15 ◽

pp. 91

Author(s):

M. Kokkoris ◽

R. Vlastou ◽

C. T. Papadopoulos ◽

A. Kontos ◽

P. Misaelides ◽

...

Keyword(s):

Differential Cross Section ◽

Cross Section ◽

Differential Cross ◽

Strong Influence ◽

Projectile Energy ◽

Published Data ◽

Resonance Mechanism ◽

Absolute Differential ◽

Nominal Thickness ◽

Natural Carbon

Absolute differential cross section measurements of the $^{12}C(d,p_{1,2,3})^{13}C$ reaction were performed in the projectile energy region Ed,lab = 900-2000 keV (in steps of 25 keV) and for detector angles between 145° and 170° (in steps of 5°) using as targets 99.9% purity self-supported natural carbon (98.9% 12C – 1.1% 13C) foils of nominal thickness ca. 1×10$^{18}$ at/cm2. The overall error in the absolute differential cross section measurements varied between ~8-30%. The results, presented in both graphical and tabular form, are compared with already published data and an attempt is made to explain the occurring differences. The strong influence of the resonance mechanism is presented and discussed.

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