Regenerative agricultural practice adoption on conventionally managed fields has gained momentum as a climate mitigation strategy, given the ability of these practices to sequester carbon or reduce greenhouse gas emissions. However, the geospatial and temporal variability of the impact of specific practices, such as cover cropping or no-till, pose challenges for scalable quantification of emissions reduction and deploying incentives to drive increased adoption. To quantify impact while accounting for variability and uncertainty at scale, Indigo Ag created a monitoring, reporting, and verification (MRV) pipeline to produce agricultural soil carbon credits produced at large scales (hundreds of thousands of hectares).
View Article and Find Full Text PDFSugarcane straw removal for bioenergy production will increase substantially in the next years, but this may deplete soil organic carbon (SOC) and exacerbate greenhouse gas (GHG) emissions. These aspects are not consistently approached in bioenergy life cycle assessment (LCA). Using SOC modeling and LCA approach, this study addressed the life cycle GHG balance from sugarcane agroindustry in different scenarios of straw removal, considering the potential SOC changes associated with straw management in sugarcane-cultivated soils in Brazil.
View Article and Find Full Text PDFLanthanide ions have ideal chemical properties for catalysis, such as hard Lewis acidity, fast ligand-exchange kinetics, high coordination-number preferences and low geometric requirements for coordination. As a result, many small-molecule lanthanide catalysts have been described in the literature. Yet, despite the ability of enzymes to catalyse highly stereoselective reactions under gentle conditions, very few lanthanoenzymes have been investigated.
View Article and Find Full Text PDFWarm dense matter (WDM) represents a highly excited state that lies at the intersection of solids, plasmas, and liquids and that cannot be described by equilibrium theories. The transient nature of this state when created in a laboratory, as well as the difficulties in probing the strongly coupled interactions between the electrons and the ions, make it challenging to develop a complete understanding of matter in this regime. In this work, by exciting isolated ∼8 nm copper nanoparticles with a femtosecond laser below the ablation threshold, we create uniformly excited WDM.
View Article and Find Full Text PDFCytochrome P450 (CYP) enzymes are heme-thiolate monooxygenases which catalyze the oxidation of aliphatic and aromatic C-H bonds and other reactions. The oxidation of halogens by cytochrome P450 enzymes has also been reported. Here we use CYP199A4, from the bacterium Rhodopseudomonas palustris strain HaA2, with a range of para-substituted benzoic acid ligands, which contain halogens, to assess if this enzyme can oxidize these species or if the presence of these electronegative atoms can alter the outcome of P450-catalyzed reactions.
View Article and Find Full Text PDFMoS nanoscrolls that have inner core radii of ∼250 nm are generated from MoS monolayers, and the optical and transport band gaps of the nanoscrolls are investigated. Photoluminescence spectroscopy reveals that a MoS monolayer, originally a direct gap semiconductor (∼1.85 eV (optical)), changes into an indirect gap semiconductor (∼1.
View Article and Find Full Text PDFGraphene oxides with different degrees of oxidation are prepared by controlling UV irradiation on graphene, and the charge transport and the evolution of the transport gap are investigated according to the extent of oxidation. With increasing oxygenous defect density nD, a transition from ballistic to diffusive conduction occurs at nD≃1012 cm-2 and the transport gap grows in proportion to nD. Considering the potential fluctuation related to the e-h puddle, the bandgap of graphene oxide is deduced to be Eg≃30nD(1012cm-2) meV.
View Article and Find Full Text PDFThe abundance of recorded protein sequence data stands in contrast to the small number of experimentally verified functional annotation. Here we screened a million-membered metagenomic library at ultrahigh throughput in microfluidic droplets for β-glucuronidase activity. We identified SN243, a genuine β-glucuronidase with little homology to previously studied enzymes of this type, as a glycoside hydrolase 3 family member.
View Article and Find Full Text PDFPurpose: Artificial intelligence (AI) and variant prioritization tools for genomic variant analysis are being rapidly developed for use in clinical diagnostic testing. However, their clinical utility and reliability are currently limited. Therefore, we performed a validation of a commercial AI tool (Moon) and a comprehensive reanalysis of previously collected clinical exome sequencing cases using an open-source variant prioritization tool (Exomiser) and the now-validated AI tool to test their feasibility in clinical diagnostics.
View Article and Find Full Text PDFIn an era of rapid global change, our ability to understand and predict Earth's natural systems is lagging behind our ability to monitor and measure changes in the biosphere. Bottlenecks to informing models with observations have reduced our capacity to fully exploit the growing volume and variety of available data. Here, we take a critical look at the information infrastructure that connects ecosystem modeling and measurement efforts, and propose a roadmap to community cyberinfrastructure development that can reduce the divisions between empirical research and modeling and accelerate the pace of discovery.
View Article and Find Full Text PDFTo meet rising demands for agricultural products, existing agricultural lands must either produce more or expand in area. Yield gaps (YGs)-the difference between current and potential yield of agricultural systems-indicate the ability to increase output while holding land area constant. Here, we assess YGs in global grazed-only permanent pasture lands using a climate binning approach.
View Article and Find Full Text PDFWe have investigated the ionization and fragmentation of a metallo-endohedral fullerene, ScN@C, using ultrashort (10 fs) x-ray pulses. Following selective ionization of a Sc (1s) electron (hν = 4.55 keV), an Auger cascade leads predominantly to either a vibrationally cold multiply charged parent molecule or multifragmentation of the carbon cage following a phase transition.
View Article and Find Full Text PDFBackground And Purpose: As the incidence of global obesity increases, concerns about adverse health outcomes in adolescents continues to rise. The complexity and expense of this problem require early recognition and specific preventive treatments. Knowledge of genetics and determinants of food choices contributing to adolescent obesity warrants further examination.
View Article and Find Full Text PDFThe field of molecular electronics aims at advancing the miniaturization of electronic devices, by exploiting single molecules to perform the function of individual components. A molecular switch is defined as a molecule that displays stability in two or more states (e.g.
View Article and Find Full Text PDFThis review focuses on recent work that has begun to establish specific functional roles for protein conformational dynamics, specifically how the conformational landscapes that proteins can sample can evolve under laboratory based evolutionary selection. We discuss recent technical advances in computational and biophysical chemistry, which have provided us with new ways to dissect evolutionary processes. Finally, we offer some perspectives on the emerging view of conformational dynamics and evolution, and the challenges that we face in rationally engineering conformational dynamics.
View Article and Find Full Text PDFDNA-based computational hardware has attracted ever-growing attention due to its potential to be useful in the analysis of complex mixtures of biological markers. Here we report the design of self-assembling logic gates that recognize DNA inputs and assemble into crossover tiles when the output signal is high; the crossover structures disassemble to form separate DNA stands when the output is low. The output signal can be conveniently detected by fluorescence using a molecular beacon probe as a reporter.
View Article and Find Full Text PDFAccurate and precise determination of mechanical properties of nanoscale materials is mandatory since device performances of nanoelectromechanical systems (NEMS) are closely related to the flexural properties of the materials. In this study, the intrinsic mechanical properties of highly stressed silicon nitride (SiN) beams of varying lengths are investigated using two different techniques: Dynamic flexural measurement using optical interferometry and quasi-static flexural measurement using atomic force microscopy. The resonance frequencies of the doubly clamped, highly stressed beams are found to be inversely proportional to their length, which is not usually observed from a beam but is expected from a string-like structure.
View Article and Find Full Text PDFEnzymes must be ordered to allow the stabilization of transition states by their active sites, yet dynamic enough to adopt alternative conformations suited to other steps in their catalytic cycles. The biophysical principles that determine how specific protein dynamics evolve and how remote mutations affect catalytic activity are poorly understood. Here we examine a 'molecular fossil record' that was recently obtained during the laboratory evolution of a phosphotriesterase from Pseudomonas diminuta to an arylesterase.
View Article and Find Full Text PDFPhilos Trans A Math Phys Eng Sci
September 2016
Super-atom molecular orbitals are orbitals that form diffuse hydrogenic excited electronic states of fullerenes with their electron density centred at the centre of the hollow carbon cage and a significant electron density inside the cage. This is a consequence of the high symmetry and hollow structure of the molecules and distinguishes them from typical low-lying molecular Rydberg states. This review summarizes the current experimental and theoretical studies related to these exotic excited electronic states with emphasis on femtosecond photoelectron spectroscopy experiments on gas-phase fullerenes.
View Article and Find Full Text PDFSingle-walled carbon nanotubes (SWCNTs) are considered pivotal components for molecular electronics. Techniques for SWCNT lithography today lack simplicity, flexibility, and speed of direct, oriented deposition at specific target locations. In this paper SWCNTs are directly drawn and placed with chemical identification and demonstrated orientation using fountain pen nanolithography (FPN) under ambient conditions.
View Article and Find Full Text PDFThe electronic structure and photoinduced dynamics of fullerenes, especially C60, is of great interest because these molecules are model systems for more complex molecules and nanomaterials. In this work we have used Rydberg Fingerprint Spectroscopy to determine the relative ionization intensities from excited SAMO (Rydberg-like) states in C60 as a function of laser wavelength. The relative ionization intensities are then compared to the ratio of the photoionization widths of the Rydberg-like states, computed in time-dependent density functional theory (TD-DFT).
View Article and Find Full Text PDFUnderstanding the extent to which enzyme evolution is reversible can shed light on the fundamental relationship between protein sequence, structure, and function. Here, we perform an experimental test of evolutionary reversibility using directed evolution from a phosphotriesterase to an arylesterase, and back, and examine the underlying molecular basis. We find that wild-type phosphotriesterase function could be restored (>10(4)-fold activity increase), but via an alternative set of mutations.
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