467 research outputs found
The Influence of Limits to Growth and Global 2000 on U.S. Environmental Governance
This paper assesses the influence of two reports, “The Limits to Growth” and “The Global 2000 Report to the President—Entering the Twenty-First Century,” on environmental governance in the United States. Published in 1972 and 1980, respectively, both reports used different methodologies to project changes to the global environment, but reached similar conclusions: business-as-usual economic growth was unsustainable and would lead to the collapse Earth’s life-support systems in the 21st century. Relying on eight oral interviews conducted with experienced and influential persons from environmental NGOs, academia, and the U.S. government, supplemented by a systematic literature review, this analysis finds Limits and Global 2000 had a limited influence on U.S. environmental governance. The reports contributed to greater awareness of the need for sustainable growth, especially among environmentalists, the U.S. government, and the business community; introduced system dynamics and computer modeling to the environmental policymaking process; and directly catalyzed some policy development, particularly in the context of international environmental negotiations. Despite these achievements, Limits and Global 2000 could not catalyze movement toward sustainable development at sufficient scale. The reports’ recommendations were rebuffed by the hostile political agenda of the Reagan Administration, their proponents frustrated by policymaking tools ill-suited to long-term system-level decisionmaking, and their message subsumed by the drive for short-term economic growth. The reports’ projections remain largely valid, but decisionmakers have long dismissed them as irrelevant
Electrochemical and Mechanistic Study of Oxidative Degradation of Favipiravir by Electrogenerated Superoxide through Proton-Coupled Electron Transfer
Electrochemical analyses aided by density functional theory calculations were used to investigate the oxidative degradation of pyrazine antiviral drugs, 3-hydroxypyrazine-2-carboxamide (T-1105) and 6-fluoro-3-hydroxypyrazine-2-carboxamide (favipiravir, T-705), by the electrogenerated superoxide radical anion (O2•–). T-1105 and T-705 are antiviral RNA nucleobase analogues that selectively inhibit the RNA-dependent RNA polymerase. They are expected as a drug candidate against various viral infections, including COVID-19. The pyrazine moiety was decomposed by O2•– through proton-coupled electron transfer (PCET). Our results show that its active form, pyrazine-ribofuranosyl-5′-triphosphate, is easily oxidized under inflamed organs by overproduced O2•– through the PCET mechanism in the immune system. This mechanistic study implies that the oxidative degradation of pyrazine derivatives will be prevented by controlling the PCET through simple modification of the pyrazine structure
Real-time Trading System based on Selections of Potentially Profitable, Uncorrelated, and Balanced Stocks by NP-hard Combinatorial Optimization
Financial portfolio construction problems are often formulated as quadratic
and discrete (combinatorial) optimization that belong to the nondeterministic
polynomial time (NP)-hard class in computational complexity theory. Ising
machines are hardware devices that work in quantum-mechanical/quantum-inspired
principles for quickly solving NP-hard optimization problems, which potentially
enable making trading decisions based on NP-hard optimization in the time
constraints for high-speed trading strategies. Here we report a real-time stock
trading system that determines long(buying)/short(selling) positions through
NP-hard portfolio optimization for improving the Sharpe ratio using an embedded
Ising machine based on a quantum-inspired algorithm called simulated
bifurcation. The Ising machine selects a balanced (delta-neutral) group of
stocks from an -stock universe according to an objective function involving
maximizing instantaneous expected returns defined as deviations from
volume-weighted average prices and minimizing the summation of statistical
correlation factors (for diversification). It has been demonstrated in the
Tokyo Stock Exchange that the trading strategy based on NP-hard portfolio
optimization for =128 is executable with the FPGA (field-programmable gate
array)-based trading system with a response latency of 164 s.Comment: 12 pages, 5 figures. arXiv admin note: text overlap with
arXiv:2307.0592
Copolymerization of Ethylene with Isobutylene and Limonene Catalyzed by Titanium Complexes with Various ansa-(Fluorenyl)(alkylamido) Ligand
A series of titanium complexes bearing ansa-(fluorenyl)(amido) ligands with cyclohexylamido, isopropylamido, and isobutylamido groups were synthesized and their catalytic behaviors for the copolymerization of ethylene with isobutylene were compared with those with cyclododecylamido and tert-butylamido groups. The effects of cocatalyst on the ethylene-isobutylene copolymerization by a titanium complex having ansa-(fluorenyl)(cyclododecylamido) ligand were examined. The catalytic activity of the titanium complex for ethylene-limonene copolymerization was also further investigated
Stabilization of a honeycomb lattice of IrO octahedra in superlattices with ilmenite-type MnTiO
In the quest for quantum spin liquids, thin films are expected to open the
way for the control of intricate magnetic interactions in actual materials by
exploiting epitaxial strain and two-dimensionality. However, materials
compatible with conventional thin-film growth methods have largely remained
undeveloped. As a promising candidate towards the materialization of quantum
spin liquids in thin films, we here present a robust ilmenite-type oxide with a
honeycomb lattice of edge-sharing IrO octahedra artificially stabilized by
superlattice formation with an ilmenite-type antiferromagnetic oxide MnTiO.
The stabilized sub-unit-cell-thick Mn-Ir-O layer is isostructural to MnTiO,
having the atomic arrangement corresponding to ilmenite-type MnTiO not
discovered yet. By spin Hall magnetoresistance measurements, we found that
antiferromagnetic ordering in the ilmenite Mn sublattice is suppressed by
modified magnetic interactions in the MnO planes via the IrO planes.
These findings lay the foundation for the creation of two-dimensional Kitaev
candidate materials, accelerating the discovery of exotic physics and
applications specific to quantum spin liquids
LiftTiles: Constructive Building Blocks for Prototyping Room-scale Shape-changing Interfaces
Large-scale shape-changing interfaces have great potential, but creating such
systems requires substantial time, cost, space, and efforts, which hinders the
research community to explore interactions beyond the scale of human hands. We
introduce modular inflatable actuators as building blocks for prototyping
room-scale shape-changing interfaces. Each actuator can change its height from
15cm to 150cm, actuated and controlled by air pressure. Each unit is low-cost
(8 USD), lightweight (10 kg), compact (15 cm), and robust, making it
well-suited for prototyping room-scale shape transformations. Moreover, our
modular and reconfigurable design allows researchers and designers to quickly
construct different geometries and to explore various applications. This paper
contributes to the design and implementation of highly extendable inflatable
actuators, and demonstrates a range of scenarios that can leverage this modular
building block.Comment: TEI 202
The N- or C-terminal cytoplasmic regions of P4-ATPases determine their cellular localization
Mammalian P4-ATPases specifically localize to the plasma membrane and the membranes of intracellular compartments. P4-ATPases contain 10 transmembrane domains, and their N- and C-terminal (NT and CT) regions face the cytoplasm. Among the ATP10 and ATP11 proteins of P4-ATPases, ATP10A, ATP10D, ATP11A, and ATP11C localize to the plasma membrane, while ATP10B and ATP11B localize to late endosomes and early/recycling endosomes, respectively. We previously showed that the NT region of ATP9B is critical for its localization to the Golgi apparatus, while the CT regions of ATP11C isoforms are critical for Ca2+-dependent endocytosis or polarized localization at the plasma membrane. Here, we conducted a comprehensive analysis of chimeric proteins and found that the NT region of ATP10 proteins and the CT region of ATP11 proteins are responsible for their specific subcellular localization. Importantly, the ATP10B NT and the ATP11B CT regions were found to harbor a trafficking and/or targeting signal that allows these P4-ATPases to localize to late endosomes and early/recycling endosomes, respectively. Moreover, dileucine residues in the NT region of ATP10B were required for its trafficking to endosomal compartments. These results suggest that the NT and CT sequences of P4-ATPases play a key role in their intracellular trafficking
The intertidal macrobenthic fauna of the Hatakejima Experimental Field, Wakayama Prefecture, Japan, in 2019
ファイル差し替え(2021-05-17)Hatakejima Experimental Field is located in Tanabe Bay, Wakayama Prefecture, Japan, which is composed of Hatakejima Island and Komarujima Islet, connected to the former in low tide. Hatakejima Island was purchased by Kyoto University and was designated as the “Hatakejima Experimental Field” in 1968. The year 2019 marks the 50th year of the long-term surveys that have been formally conducted on the experimental field since 1969 (i.e., the Century of Research Project). We conducted a field survey to record the macrobenthic fauna of the experimental field in 2019. A total of 168 species of 11 phyla were recorded in this survey. In each phylum, the number of species is listed as follows in descending order: Mollusca (78 spp.), Arthropoda (27 spp.), Echinodermata (23 spp.), Annelida (21 spp.), Cnidaria (7 spp.), Porifera (3 spp.), Nemertea (3 spp.), Platyhelminthes (2 spp.), Chordata (2 spp.), Bryozoa (1 sp.), and Hemichordata (1 sp.). We also recorded and discussed the influence of recent environmental changes around the Hatakejima Experimental Field. Tropical sea urchin species disappeared in the winter of 2017–2018 following the large meander of the Kuroshio Current, which led to decreasing water temperatures. The population of the seagrass Zostera japonica drastically decreased on the western sandy shore of the island in 2019, most likely because of two big typhoons in September 2018. We must conduct continuous observations to aid the recovery of seagrass-associated communities and protect the experimental field to keep high biodiversity of macrobenthic fauna in the future
Innovative Separation Technology Utilizing Marine Bioresources: Multifaceted Development of a Chitosan-Based System Leading to Environmentally-Friendly Processes
Chitosan, known as a most typical marine biological polymer, has a fruitful capability of biocompatible gel formation. Attempts of chitosan have been made to develop it from the multifaceted viewpoint of separation technology. The physicochemical properties of chitosan containing a lot of hydroxyl groups and reactive amino groups help to build the characteristic polymer networks. The deacetylation degree of chitosan is found as the most influential factor to regulate properties of chitosan hydrogels. The antibacterial activity of the chitosan membrane is one of its notable abilities because of its practical application. The chitosan, its derivatives, and the complex formation with other substances has been used for applications in filtration and membrane separation processes. Adsorption processes based on chitosan have been also developed widely. Moreover, complex of chitosan gel helps to immobilize adsorbent particles. The chitosan membrane immobilizing Prussian-Blue for cesium ion removal from the aqueous phase is one of the leading cases. To elaborate the adsorption behavior on the chitosan immobilizing adsorbent, the isothermal equilibrium and mass transfer characteristics can be discussed. The adsorption process using chitosan-based membranes in combination with filtration in a flow process is advantageous compared with the batch process. More advanced studies of chitosan aerogel and chitosan nanofibers have been proceeded recently, especially for adapting to water purification and air filtration
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