Land-based climate solutions for the United States

Funding Information: We thank many colleagues for helpful discussion and feedback during the preparation of this analysis, anonymous reviewers for constructive criticism, and J.L. Schuette for help with data assembly. Financial support was provided by the U.S. Department of Energy Great Lakes Bioenergy Research Center (Award DE‐SC0018409), the U.S. National Science Foundation Long‐term Ecological Research Program (DEB 1832042), the USDA Long‐term Agroecosystem Research program, and Michigan State University AgBioResearch. Additional support (PS) is from the Soils‐R‐GGREAT (NE/P019455/1) and CIRCASA (Agreement 774378) projects of the European Union‘s Horizon 2020 Research and Innovation Programme (Award 774378); and (KP) the U.S. Department of Energy Advanced Research Projects Agency‐Energy program (Award DE‐AR0000826). KP serves as a part‐time advisor to Indigo Ag, Inc., a company that markets soil carbon sequestration credits. The authors declare no other potential conflicts of interest. Publisher Copyright: © 2022 The Authors. Global Change Biology published by John Wiley & Sons Ltd.Peer reviewedPublisher PD

Denitrification by sulfur-oxidizing bacteria in a eutrophic lake

Understanding the mechanistic controls of microbial denitrification is of central importance to both environmental microbiology and ecosystem ecology. Loss of nitrate (NO3 −) is often attributed to carbon-driven (heterotrophic) denitrification. However, denitrification can also be coupled to sulfur (S) oxidation by chemolithoautotrophic bacteria. In the present study, we used an in situ stable isotope (15NO3 −) tracer addition in combination with molecular approaches to understand the contribution of sulfur-oxidizing bacteria to the reduction of NO3 − in a eutrophic lake. Samples were incubated across a total dissolved sulfide (H2S) gradient (2 to 95 μM) between the lower epilimnion and the upper hypolimnion. Denitrification rates were low at the top of the chemocline (4.5 m) but increased in the deeper waters (5.0 and 5.5 m), where H2S was abundant. Concomitant with increased denitrification at depths with high sulfide was the production of sulfate (SO4 2−), suggesting that the added NO3 − was used to oxidize H2S to SO4 2−. Alternative nitrate removal pathways, including dissimilatory nitrate reduction to ammonium (DNRA) and anaerobic ammonium oxidation (anammox), did not systematically change with depth and accounted for 1 to 15% of the overall nitrate loss. Quantitative PCR revealed that bacteria of the Sulfurimonas genus that are known denitrifiers increased in abundance in response to NO3 − addition in the treatments with higher H2S. Stoichiometric estimates suggest that H2S oxidation accounted for more than half of the denitrification at the depth with the highest sulfide concentration. The present study provides evidence that microbial coupling of S and nitrogen (N) cycling is likely to be important in eutrophic freshwater ecosystems

Relaxation of Microwave Nonlinearity in a Cuprate Superconducting Resonator

The second- and third-order nonlinear microwave response of a superconducting YBa2Cu3O7 thin-film resonator was synchronously measured using three input tones. This technique permits the local measurement, and hence mapping, of intermodulation distortion inside the resonator. Second- and third-order IMD measured with a fixed probe relaxed in remarkably different ways after the removal of a static magnetic field. The second-order IMD relaxed by two different magnetic processes, a fast process that appears related to bulk remanent magnetization and a slow process that fits the description of Bean and Livingston. The third-order IMD relaxes by only one process that is distinct from the two processes controlling second order relaxation

Fundamental representations and algebraic properties of biquaternions or complexified quaternions

The fundamental properties of biquaternions (complexified quaternions) are presented including several different representations, some of them new, and definitions of fundamental operations such as the scalar and vector parts, conjugates, semi-norms, polar forms, and inner and outer products. The notation is consistent throughout, even between representations, providing a clear account of the many ways in which the component parts of a biquaternion may be manipulated algebraically

An Inversion Method for Measuring Beta in Large Redshift Surveys

A precision method for determining the value of Beta= Omega_m^{0.6}/b, where b is the galaxy bias parameter, is presented. In contrast to other existing techniques that focus on estimating this quantity by measuring distortions in the redshift space galaxy-galaxy correlation function or power spectrum, this method removes the distortions by reconstructing the real space density field and determining the value of Beta that results in a symmetric signal. To remove the distortions, the method modifies the amplitudes of a Fourier plane-wave expansion of the survey data parameterized by Beta. This technique is not dependent on the small-angle/plane-parallel approximation and can make full use of large redshift survey data. It has been tested using simulations with four different cosmologies and returns the value of Beta to +/- 0.031, over a factor of two improvement over existing techniques.Comment: 16 pages including 6 figures Submitted to The Astrophysical Journa

The effects of preeclampsia on signaling to hematopoietic progenitor cells

Background: The role of the microenvironment is important in cell differentiation. The effect of placental disease on the growth and differentiation and hematopoietic stem cells has not been well-studied. Methods: Enzyme linked immunoassay was used to measure erythropoietin and osteopontin in plasma from umbilical cord blood of children born to normotensive and preeclamptic women. Additionally, CD34+ cells were isolated from umbilical cord blood and grown in complete methylcellulose media. Colony types were identified and enumerated. Results: Differences in the concentration of erythropoietin in the cord blood between the controls and the preeclamptics approached significance (P = 0.067) using a Mann-Whitney U test. In the plasma of cord blood from children born to normotensive women, the median erythropoietin was 0.186 mIU/mL compared to 1.986 mIU/mL in children of preeclamptic women. We did not find any significant differences in the number and types of colonies; however, there was a trend toward increased BFU-E in the preeclamptic samples. Furthermore, this trend for increased BFU-E colonies was also seen from CD34+ cells isolated from umbilical cord blood of severe preeclamptics compared to mild. Conclusion: Our preliminary studies suggest that abnormalities in the placenta, such as those found when the mother experiences preeclampsia, may affect the ability of hematopoietic stem cells to grow and differentiate

The relationship between obesity, pregnancy, and levels of indoleamine 2,3-dioxygenase

For a successful pregnancy to occur, foreign genetic material such as the allogeneic fetus must be tolerated within the maternal host. Indoleamine 2,3-dioxygenase (IDO) is an enzyme induced by pro-inflammatory cytokines that has been shown to be key to this process. Obesity as a pro-inflammatory state is associated with poor obstetric outcomes. The primary objective of this study is to investigate the relationship between obesity and IDO activity

Design of trip current monitoring system for circuit breaker condition assessment

A distributed system, which supports circuit breaker maintenance and asset management, is described. It uses a client/server architecture for propagating expert knowledge from switchgear maintenance experts directly to maintenance operatives for on-site circuit breaker condition assessment and diagnosis. Prior research in the field of distribution level circuit breaker condition monitoring has shown the trip coil of a circuit breaker yields a current profile that, when tripped, can subsequently be interpreted as an indicator of plant health. Exploiting existing circuit breaker test equipment, a centralised archive of asset condition is built from routine tests permitting experts to examine trends in the data and pass their definition of the operating conditions to personnel in the field. This provides diagnostic support to engineers in the field. The system is currently in use as the subject of a pilot study conducted by SP PowerSystems intended to improve its ongoing maintenance and asset management activities

Spatial and Temporal Variation of Offshore Wind Power and its Values Along the Central California Coast

The analysis of the spatiotemporal variability of wind power remains limited during the planning stage of an offshore wind farm. This study provides a framework to investigate how offshore wind power varies along the Central California Coast over diurnal and seasonal time scales, which is critical for reliability and functionality of the grid system. We find that offshore wind power in this region peaks during evening hours across all seasons and maximizes in spring and summer. The timing of peak offshore wind power production better aligns with that of peak demand across California than solar and land-based wind power production, highlighting its potential to fill the supply gap when demand is high and power production from other renewable energy sources is low. We further assess the value of offshore wind power using demand-based and wholesale market metrics. Both metrics indicate high potential value of offshore wind power over most areas in this region. Finally, we show that the estimate of power production is significantly biased when using mean wind speeds that do not account for temporal variability, leading to potentially inaccurate predictions about locations that are expected to produce the most power. These results reiterate the importance in considering spatiotemporal variability in wind power for accurately calculating the value of offshore wind development

Seasonal decline in leaf photosynthesis in perennial switchgrass explained by sink limitations and water deficit

Leaf photosynthesis of perennial grasses usually decreases markedly from early to late summer, even when the canopy remains green and environmental conditions are favorable for photosynthesis. Understanding the physiological basis of this photosynthetic decline reveals the potential for yield improvement. We tested the association of seasonal photosynthetic decline in switchgrass (Panicum virgatum L.) with water availability by comparing plants experiencing ambient rainfall with plants in a rainfall exclusion experiment in Michigan, USA. For switchgrass exposed to ambient rainfall, daily net CO2 assimilation ( Anet') declined from 0.9 mol CO2 m-2 day-1 in early summer to 0.43 mol CO2 m-2 day-1 in late summer (53% reduction; P<0.0001). Under rainfall exclusion shelters, soil water content was 73% lower and Anet' was 12% and 26% lower in July and September, respectively, compared to those of the rainfed plants. Despite these differences, the seasonal photosynthetic decline was similar in the season-long rainfall exclusion compared to the rainfed plants; Anet' in switchgrass under the shelters declined from 0.85 mol CO2 m-2 day-1 in early summer to 0.39 mol CO2 m-2 day-1 (54% reduction; P<0.0001) in late summer. These results suggest that while water deficit limited Anet' late in the season, abundant late-season rainfalls were not enough to restore Anet' in the rainfed plants to early-summer values suggesting water deficit was not the sole driver of the decline. Alongside change in photosynthesis, starch in the rhizomes increased 4-fold (P<0.0001) and stabilized when leaf photosynthesis reached constant low values. Additionally, water limitation under shelters had no negative effects on the timing of rhizome starch accumulation, and rhizome starch content increased ~ 6-fold. These results showed that rhizomes also affect leaf photosynthesis during the growing season. Towards the end of the growing season, when vegetative growth is completed and rhizome reserves are filled, diminishing rhizome sink activity likely explained the observed photosynthetic declines in plants under both ambient and reduced water availability