In this study, the 2008 earthquake in Wenchuan, China serves as a natural experiment for examining the effect of natural disasters on high-stakes exam performance among students who were admitted to four-year colleges between 2005 and 2011. Results of a generalized difference-in-differences model show that, on average, the earthquake reduced a student's National College Entrance Examination (NCEE) standard score by 55% of a standard deviation. The findings have implications for higher education and China's economy, because earthquake exposure lowers a student's probability of being accepted to an elite college, pursuing a major in a high-salary field, and moving to a highly developed urban area for education or employment.
Phosphate addition is commonly applied to remediate lead contaminated sites via the formation of lead phosphate particles with low solubility. However, the effects of natural organic matter (NOM) with different properties, as well as the contributions of specific interactions (particle-particle, particle-NOM, and NOM-NOM) in enhanced stabilization or flocculation of the particles, are not currently well understood. This study investigates the influence of two aquatic NOM and two soil or coal humic acid (HA) extracts on the aggregation behavior of lead phosphate particles and explores the controlling mechanisms. All types of NOM induced disaggregation and steric stabilization of the particles in the presence of Na+ (100 mM) or low (1 mM) Ca2+ concentrations, as well as at low NOM concentrations (1 mgC/L). However, for the soil and coal HA, a threshold at NOM concentrations of 10 mgC/L and high (3 mM) Ca2+ concentrations was observed where bridging flocculation (rather than steric stabilization) occurred. In situ attenuated total reflectance – Fourier transform infrared characterization confirmed adsorption of the soil and coal humic acid extracts (10 mgC/L) onto the surface of the lead phosphate particles in 3 mM Ca2+, whereas dynamic and static light scattering demonstrated extensive HA flocculation that dominated the overall scattered light intensities. These results imply that the accelerated aggregation was induced by a combination of HA adsorption and bridging flocculation by Ca2+. Overall, this research demonstrates that the type of NOM is critical to predict the colloidal stability of lead phosphate particles. Aquatic NOM stabilized the particles under all conditions evaluated, but soil or coal HA with higher molecular weight and aromaticity showed highly variable stabilization or flocculation behavior depending on the HA and Ca2+ concentrations available to adsorb to the particles and participate in bridging. These results provide new mechanistic insights on particle stabilization or destabilization by NOM.
Abstract Spatiotemporal manipulation of biological processes in living animals using noninvasive, remote-controlled stimuli is a captivating but challenging endeavor. Herein, we present the development of a biocompatible photocatalytic technology termed CAT-NIR, which uses external near infrared light (NIR, 740?nm) to trigger decaging reactions in living mice. The Os(II) terpyridine complex was identified as an efficient NIR photocatalyst for promoting deboronative hydroxylation reactions via superoxide generation in the presence of NIR light, resulting in the deprotection of phenol groups and the release of bioactive molecules under living conditions. The validation of the CAT-NIR system was demonstrated through the NIR-triggered rescue of fluorophores, prodrugs as well as biomolecules ranging from amino acids, peptides to proteins. Furthermore, by combining genetic code expansion and computer-aided screening, CAT-NIR could regulate affibody binding to the cell surface receptor HER2, providing a selective cell tagging technology through external NIR light. In particular, the tissue-penetrating ability of NIR light allowed for facile prodrug activation in living mice, enabling noninvasive, remote-controlled rescue of drug molecules. Given its broad adaptability, this CAT-NIR system may open new opportunities for manipulating the functions of bioactive molecules in living animals using external NIR light with spatiotemporal resolution.
The porous defective MIL-88B(Fe) with abundant oxygen vacancies and Fe-N sites was fabricated to accomplish nearly zero peroxydisulfate (PDS) consumption for persistent bisphenol A (BPA) degradation via electron-transfer pathway (ETP). Interestingly, the generated sulfates during ETP were oxidized to yield the confined sulfate radicals and to accomplish the peroxydisulfate regeneration in the fine-tuned MIL-88B(Fe), which was verified by series experiments and DFT calculations. Further studies suggested that the optimal De-MIL-88B(Fe)-1.25 catalyst achieved the persistent nonradical reactions for BPA decomposition under visible light irradiation with both low input and low consumption of PDS. It was the first case to achieve nearly zero PDS consumption for emerging pollutants elimination, which provided new strategy to design and tune defective metal-organic frameworks for the purpose of reducing the stoichiometry between PDS and contaminants for nearly zero PDS consumption.
Given the deficiencies of traditional government capacity indicators and cultural factors (e.g., individualism) in explaining the discrepancies of different agents' responses to the coronavirus disease 2019 (COVID-19) pandemic, the present study proposed and examined the role of neoliberalism, a novel cultural tradition of knowledge emphasizing the principles of free markets and self-governance, as an additional explanation of the discrepancies in the governmental and individual responses to the pandemic. Analyzing policy responses of 106 nations and personal responses from 105,203 individuals in 104 nations during the first wave of the pandemic, we found that nation-level neoliberalism (delineated by the economic freedom index) negatively predicted the nonlinear trajectories of government policy responses to contain the pandemic. Specifically, in more neoliberal countries, stringent containment policy responses showed a sharper decline in the later stage of the first wave of the pandemic. Moreover, nation-level neoliberalism negatively predicted individuals' pandemic-protective attitudes and behaviors. All these effects are independent of and incremental to those of nation-level individualism. In conclusion, this study sheds light on how neoliberalism could lead to negative consequences during large-scale, long-lasting public threats, offering practical guidance for adjusting public crisis management in the future.
Abstract Aim Quantifying niche shifts of non-native species and their interactions with natives is vital in evaluating invasion risk yet remains difficult. Climate filtering and competition with native congeners are two important processes impacting niche changes and yielding contradictory predictions for the coexistence of non-native and native species. Closely related species representing the Eastern Asia (EA)?Eastern North America (ENA) floristic disjunction provide a powerful yet unexplored system for assessing the relative roles of these two processes. Here, we tested three niche change scenarios (unfilling, expansion and stable) using EA species naturalized in ENA. We aim to answer: (1) which scenario is observed for naturalized species? and (2) how has niche overlap between EA and ENA congeners changed after naturalization? Location ENA and EA. Time Period Present. Major Taxa Studied Angiosperms. Methods Niches were estimated using both occurrences and predictions generated by ecological niche models. Niche changes of naturalized species and their niche overlap with natives were measured using Schoener's D. Contributions of niche expansion and unfilling on niche changes of naturalized niches were evaluated using hierarchical partitioning and linear regressions. We further measured pairwise phylogenetic distances among EA and ENA congeners and evaluated the association with niche overlap. Results Unfilling-dominated postintroduction niche changes of the naturalized species. EA species naturalized in ENA exhibited lower niche overlap with ENA native congeners compared with native range populations in EA. These results remain when considering time since introduction and potential physical dispersal limitations interpreted by projecting suitable niche space between EA and ENA. However, dispersal limitation may contribute to the degree of niche unfilling. Main Conclusions Using intercontinental disjunct species as a study system, we found that naturalization is shaped jointly by climate filtering and competition with native congeners, providing valuable insights for evaluating invasion risk underlying global floristic exchanges.
The development of nickel isotopes as a chemical tracer of past ocean environments requires a sound understanding of the modern oceanic budget. Our current understanding of this budget implies a large elemental and isotope imbalance between inputs to and outputs from the dissolved pool of the ocean. This imbalance is mainly caused by the dominant oxic sink of Ni to Mn oxide-rich sediments. Though the Ni isotope composition of Fe-Mn crusts has previously been used as proxy for the Ni isotope composition of these sediments, crusts and nodules represent a very small part of the total Mn oxide output. Instead, Mn oxide microparticle supply to pelagic and hemi-pelagic sediments dominates the removal of Mn to sediments, but there are very few isotope data for such samples. Here we present the first extensive Ni concentration and isotope dataset from fully oxic Mn-rich pelagic sediments, from 6 different sites across the open Pacific and 10 closely-spaced sites in the Indian Ocean. We also present data for one hemi-pelagic site representing a suboxic setting on the California Margin. Abyssal Pacific and Indian Ocean sediments have a Ni/Mn ratio of 0.02 (similar to Fe-Mn crusts) and their authigenic Ni is isotopically lighter (δ60Ni = +0.26 to +1.08‰) than seawater (+1.33‰) and crusts (+1.55±0.38‰). Data presented here for organic carbon-rich suboxic sediments of the Californian margin have lower Ni/Mn ratios (0.004 to 0.014 for the oxic top of the core, where Mn oxide is present in abundance) and even lighter authigenic Ni isotope compositions (δ60Ni = -0.08±0.11‰). We show that the Ni isotopes of nearly all Mn-rich sediments and deposits analysed to date, including the new data presented here, are correlated with Co/Mn ratios, suggesting that both are controlled by accumulation rate, progressive incorporation of Ni into the metal oxide structure and isotopic re-equilibration between the solid and aqueous phase. At sites where sediments are diagenetically processed, such as the California Margin, differential diagenetic remobilisation of Mn, Ni and Co cause deviations from this correlation. We present a new mass balance calculation that recognises the importance of scavenging of oceanic Ni to Mn oxide-rich proximal hydrothermal sediments, with low Ni/Mn and light isotope compositions. The mass balance produces a budget that can be simultaneously balanced for both amounts and isotope compositions of Ni. This result provides a strong basis for the application of Ni isotopes as records of the evolution of the metal sink from the oxic oceans through Earth history.
An approach to generalize any kind of collinear functional in density functional theory to noncollinear functionals is proposed. This approach satisfies the correct collinear limit for any kind of functional, guaranteeing that the exact collinear functional after generalization is still exact for collinear spins. Besides, it has well-defined and numerically stable functional derivatives, a desired feature for noncollinear and spin-flip time-dependent density functional theory. Furthermore, it provides local torque, hinting at its applications in spin dynamics.
Multispectral photometric stereo (MPS) aims at recovering the surface normal of a scene from a single-shot multispectral image captured under multispectral illuminations. Existing MPS methods adopt the Lambertian reflectance model to make the problem tractable, but it greatly limits their application to real-world surfaces. In this paper, we propose a deep neural network named NeuralMPS to solve the MPS problem under non-Lambertian spectral reflectances. Specifically, we present a spectral reflectance decomposition model to disentangle the spectral reflectance into a geometric component and a spectral component. With this decomposition, we show that the MPS problem for surfaces with a uniform material is equivalent to the conventional photometric stereo (CPS) with unknown light intensities. In this way, NeuralMPS reduces the difficulty of the non-Lambertian MPS problem by leveraging the well-studied non-Lambertian CPS methods. Experiments on both synthetic and real-world scenes demonstrate the effectiveness of our method.
Nonlocal modeling has drawn more and more attention and becomes steadily more powerful in scientific computing. In this paper, we demonstrate the superiority of a first-principle nonlocal model—Wigner function—in treating singular potentials which are often used to model the interaction between point charges in quantum science. The nonlocal nature of the Wigner equation is fully exploited to convert the singular potential into the Wigner kernel with weak or even no singularity, and thus highly accurate numerical approximations are achievable, which are hardly designed when the singular potential is taken into account in the local Schrödinger equation. The Dirac delta function, the logarithmic, and the inverse power potentials are considered. Numerically converged Wigner functions under all these singular potentials are obtained with a fourth-order accurate operator splitting spectral method, and display many interesting quantum behaviors as well.
In this work, an excitonic energy transfer (EET) based non-radical mechanism was proposed for the degradation of organic pharmaceuticals by graphitic carbon nitride (g-C3N4) under visible light irradiation. Using diclofenac (DCF) as a model molecule, the competition between single electron transfer (SET) and EET was studied through modulating the exciton binding energy of g-C3N4. The different mechanisms of SET and EET for DCF degradation were predicted by DFT calculation, and further confirmed by their different degradation pathways. When EET played an important role, the rationality of some very popular radical scavengers, such as p-BQ, TEMPOL and furfuryl alcohol must be reconsidered. In addition, humic acid (HA) had a distinct effect on EET and SET. Specifically, HA enhanced the EET process through photosensitization, but suppressed SET through radical quenching effect. The effect of HA on DCF degradation depended on the contribution ratio of SET and ET.