The COVID-19 pandemic has spurred controversies related to whether countries manipulate reported data for political gains. We study the association between accuracy of reported COVID-19 data and ...developmental indicators. We use the Newcomb-Benford law (NBL) to gauge data accuracy. We run an OLS regression of an index constructed from developmental indicators (democracy level, gross domestic product per capita, healthcare expenditures, and universal healthcare coverage) on goodness-of-fit measures to the NBL. We find that countries with higher values of the developmental index are less likely to deviate from the Newcomb-Benford law. The relationship holds for the cumulative number of reported deaths and total cases but is more pronounced for the death toll. The findings are robust for second-digit tests and for a sub-sample of countries with regional data. The NBL provides a first screening for potential data manipulation during pandemics. Our study indicates that data from autocratic regimes and less developed countries should be treated with more caution. The paper further highlights the importance of independent surveillance data verification projects.
Contrary to the common view that analysts are important information agents, intraday returns evidence shows that announcements of analysts' forecast revisions release little new information, on ...average. Further cross-sectional evidence from returns around the announcements confirms that revisions are virtually information free. Daily announcement returns used in the literature appear to overstate the analyst's role as information agent, because forecast announcements are often issued directly after reports of significant news about the followed firm. The evidence reveals a sequential relationship between events and news and forecast revisions indicative of analyst piggybacking, not prophecy. These new findings about the most sought-after analyst reports broaden significantly the evidence indicating that price reactions to analysts' reports reveal little new information.
This paper was accepted by Brad Barber, finance.
One of the distinctive features of eubacterial retinal-based proton pumps, proteorhodopsins, xanthorhodopsin, and others, is hydrogen bonding of the key aspartate residue, the counterion to the ...retinal Schiff base, to a histidine. We describe properties of the recently found eubacterium proton pump from Exiguobacterium sibiricum (named ESR) expressed in Escherichia coli, especially features that depend on Asp–His interaction, the protonation state of the key aspartate, Asp85, and its ability to accept a proton from the Schiff base during the photocycle. Proton pumping by liposomes and E. coli cells containing ESR occurs in a broad pH range above pH 4.5. Large light-induced pH changes indicate that ESR is a potent proton pump. Replacement of His57 with methionine or asparagine strongly affects the pH-dependent properties of ESR. In the H57M mutant, a dramatic decrease in the quantum yield of chromophore fluorescence emission and a 45 nm blue shift of the absorption maximum with an increase in the pH from 5 to 8 indicate deprotonation of the counterion with a pK a of 6.3, which is also the pK a at which the M intermediate is observed in the photocycle of the protein solubilized in detergent dodecyl maltoside (DDM). This is in contrast with the case for the wild-type protein, for which the same experiments show that the major fraction of Asp85 is deprotonated at pH >3 and that it protonates only at low pH, with a pK a of 2.3. The M intermediate in the wild-type photocycle accumulates only at high pH, with an apparent pK a of 9, via deprotonation of a residue interacting with Asp85, presumably His57. In liposomes reconstituted with ESR, the pK a values for M formation and spectral shifts are 2–3 pH units lower than in DDM. The distinctively different pH dependencies of the protonation of Asp85 and the accumulation of the M intermediate in the wild-type protein versus the H57M mutant indicate that there is strong Asp–His interaction, which substantially lowers the pK a of Asp85 by stabilizing its deprotonated state.
Polymer composites with various recycled poly(ethylene terephthalate)-based (PET-based) polyester matrices (poly(ethylene terephthalate), copolyesters, and unsaturated polyester resins), similar in ...properties to the primary ones, can be obtained based on PET glycolysis products after purification. PET glycolysis allows one to obtain bis(2-hydroxyethyl) terephthalate and oligo(ethylene terephthalates) with various molecular weights. A kinetic model of poly(ethylene terephthalate) homogeneous glycolysis under the combined or separate action of oligo(ethylene terephthalates), bis(2-hydroxyethyl) terephthalate, and ethylene glycol is proposed. The model takes into account the interaction of bound, terminal, and free ethylene glycol molecules in the PET feedstock and the glycolysis agent. Experimental data were obtained on the molecular weight distribution of poly(ethylene terephthalate) glycolysis products and the content of bis(2-hydroxyethyl) terephthalate monomer in them to verify the model. Homogeneous glycolysis of PET was carried out at atmospheric pressure in dimethyl sulfoxide (DMSO) and N-methyl-2-pyrrolidone (NMP) solvents with catalyst based on antimony trioxide (Sb
O
) under the action of different agents: ethylene glycol at temperatures of 165 and 180 °C; bis(2-hydroxyethyl) terephthalate at 250 °C; and oligoethylene terephthalate with polycondensation degree 3 at 250 °C. Homogeneous step-by-step glycolysis under the successive action of the oligo(ethylene terephthalate) trimer, bis(2-hydroxyethyl) terephthalate, and ethylene glycol at temperatures of 250, 220, and 190 °C, respectively, was also studied. The composition of products was confirmed using FTIR spectroscopy. Molecular weight characteristics were determined using gel permeation chromatography (GPC), the content of bis(2-hydroxyethyl) terephthalate was determined via extraction with water at 60 °C. The developed kinetic model was found to be in agreement with the experimental data and it could be used further to predict the optimal conditions for homogeneous PET glycolysis and to obtain polymer-based composite materials with desired properties.
•We developed the SAW atomizer for deposition of graphene oxide nanofilms.•Different graphene were deposited by subsequent droplet-by-droplet atomization.•The SAW humidity sensor with these films was ...characterized and calibrated.•Multi-exponential model of adsorption was used to explain the experimental results.•All parameters of this model were experimentally evaluated.
Symmetric surface acoustic wave (SAW) atomizer was used to deposit graphene oxide (GO) nanofilms from microdroplets of the aqueous GO dispersion onto the surface of the SAW humidity sensors. The sensors with the deposited GO films were tested in a wide range of relative humidity and showed the amplitude of the response in the range of 1–40kHz sufficient for the majority of applications. The kinetics of the adsorption of water molecules was modeled using the assumption that two independent first order adsorption processes take place. Saturation amplitudes and rate coefficients for both processes were experimentally evaluated using LSQ fitting of the sensor response in the time domain for the films obtained by different number of depositions. The mechanism of the adsorption of water molecules to the GO flakes is proposed and discussed.
In this research, we have developed the approach to controlled synthesis of acrylonitrile-acrylamide copolymers with narrow molecular weight distribution and various monomer sequence distributions. ...By using dibenzyl trithiocarbonate and batch/semibatch polymerization, we have first synthesized random, gradient, and block-gradient copolymers containing 3.4–10.2 mol. % of acrylamide and revealed the influence of the monomer sequence on the cyclization behavior of poly(acrylonitrile-co-acrylamide) by combination of differential scanning calorimetry and Fourier transform infrared spectroscopy. This allowed us to find differences in cyclization behavior of the copolymers in argon and air atmosphere. Intramolecular cyclization was the main process proceeding in argon atmosphere. The radical mechanism of cyclization was suppressed already at the molar part of acrylamide units in copolymer exceeding ~3 mol. % for random copolymer and ~6 mol. % for block-gradient copolymer. The activation energy of ionic cyclization was equal to 89 ± 3 kJ·mol−1 and was not influenced by both copolymer composition and chain microstructure in contrast to the rate of cyclization. The latter was increased with the rise of acrylamide content, the content of hetero-triads and in the range block-gradient < gradient < random structure. In air atmosphere, the oxidation reactions dominated over cyclization. The oxidation reactions were found to be less sensitive to copolymer composition and chain microstructure.
Laboratory experiments were carried out to test the electroslag remelting of corrosion-resistant titaniumalloyed steel using AKF235 low-silicon flux. The titanium loss in these experiments was ...compared with the available literature data on titanium loss in similar steels during electroslag remelting using ANF-29 high-silicon flux. It is shown that the use of AKF235 flux reduces the titanium loss if all the other conditions (content of titanium dioxide in slag and slag deoxidation conditions) are equal. If the content of titanium dioxide in the starting flux is 2.5%, the titanium loss is practically suppressed by a sufficient amount of deoxidizers added to the slag: 6 g Al and 1.5 g Ti per 1 kg of melted metal. Reducing the weights of added deoxidants to 3 g Al and 0.5 g Ti per 1 kg of melted metal, as well as reducing the content of titanium dioxide in the slag increase the titanium loss.
Retinal proteins function as photoreceptors and ion pumps. Xanthorhodopsin of Salinibacter ruber is a recent addition to this diverse family. Its novel and distinctive feature is a second ...chromophore, a carotenoid, which serves as light-harvesting antenna. Here we discuss the properties of this carotenoid/retinal complex most relevant to its function (such as the specific binding site controlled by the retinal) and its relationship to other retinal proteins (bacteriorhodopsin, archaerhodopsin, proteorhodopsin and retinal photoreceptors of archaea and eukaryotes). Antenna addition to a retinal protein has not been observed among the archaea and emerged in bacteria apparently in response to environmental conditions where light-harvesting becomes a limiting factor in retinal protein functioning.
The article presents results of the calculation of pollutants emitted into the atmospheric air in Chita. The approach to the zoning of the city territory with a population of more than 350 thousand ...people is described. By the results of calculation and assessment of health risks, which are based on the data of modeling the dispersion of harmful impurities, the zones of exposure to chemical impurities were identified. The zoning by the risk degree is relevant for assessing the danger to the population and the impact on the environment. The list of priority impurities was substantiated, taking into account carcinogenic and/or non-carcinogenic risks, and the results of calculations of dispersion and allocation of marker indicators for emissions from enterprises that make the greatest contributions to the air pollution. The methods used in Chita help identify areas with the greatest risks to public health.
The use of a delay-locked loop (DLL) for conditioning signals from a surface acoustic wave (SAW) sensor is proposed. The system consists of a reference oscillator and a DLL. The signal generated in ...the reference oscillator is propagated through a sensitive SAW delay line (SAW-DL). The SAW propagating through this structure has a phase velocity dependent on environmental parameters such as temperature, humidity, mechanical deformation, or analyte concentration. Therefore, the system measures the physical quantity of interest by tracking the delay caused by the sensitive SAW-DL via a DLL. Fully digital DLL is made use of for the delay-tracking, which provides the conversion of the environmental parameter being sensed directly to the digital domain. The system is demonstrated through results from behavioural simulation, using a model of an SAW-DL sensitive to humidity.
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