80 research outputs found
Robust portfolio optimization with a generalized expected utility model under ambiguity
Robust optimization, Portfolio selection, Ambiguity, Equilibrium, C02, C44, D81,
Parents' Decisions to Vaccinate Children against COVID-19: A Scoping Review.
Since 2019, the COVID-19 pandemic has resulted in sickness, hospitalizations, and deaths of the old and young and impacted global social and economy activities. Vaccination is one of the most important and efficient ways to protect against the COVID-19 virus. In a review of the literature on parents' decisions to vaccinate their children, we found that widespread vaccination was hampered by vaccine hesitancy, especially for children who play an important role in the coronavirus transmission in both family and school. To analyze parent vaccination decision-making for children, our review of the literature on parent attitudes to vaccinating children, identified the objective and subjective influencing factors in their vaccination decision. We found that the median rate of parents vaccinating their children against COVID-19 was 59.3% (IQR 48.60~73.90%). The factors influencing parents' attitudes towards child vaccination were heterogeneous, reflecting country-specific factors, but also displaying some similar trends across countries, such as the education level of parents. The leading reason in the child vaccination decision was to protect children, family and others; and the fear of side effects and safety was the most important reason in not vaccinating children. Our study informs government and health officials about appropriate vaccination policies and measures to improve the vaccination rate of children and makes specific recommendations on enhancing child vaccinate rates
On the database-based strategy of candidate extractant generation for de-phenol process in coking wastewater treatment
A database-based strategy of candidate generation was proposed for molecular design of new de-phenol extractants following the idea of finding new applications of existing commercial compounds. The strategy has the advantage that the environmental, safety and health risks of candidate compounds are known and controllable. In this work, the Existing Commercial Compounds (ECC) database and special combined search strategy were developed as the base for the proposed CAMD method following such idea, and molecules for phenol extraction used in coking wastewater treatment were selected from the ECC database. The candidate solvents cover the following categories: ketones, esters, ethers, alcohols, anhydrides and benzene compounds, which are consistent with the de-phenol extractants commonly used in the industry or experiment. The compounds with higher partition coefficient and selectivity than widely used methyl isobutyl ketone (MIBK) are mainly ketones. 26 obtained molecules show higher partition coefficient and selectivity than MIBK, which are suggested to be further investigated by experiment. Furthermore, analysis of these potential molecules may present the effective functional groups as the initial group set to generate new molecular structures of de-phenol extractants. The results show that the proposed method enables us to efficiently generate chemicals with benefits of less time, less economical cost, and known environmental impact as well. (C) 2017 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. All rights reserved
DOSE-COMPARISON STUDY OF PREDNISONE FOR RENAL WATER AND SODIUM EXCRETION IN DECOMPENSATED HEART FAILURE
Effects of 4d transition metals doping on the photocatalytic activities of anatase TiO2 (101) surface
Aiming at improving the visible-light photocatalytic activities of TiO2(101) surface we make an in-depth study on the TiO2(101) doped with 4d transition metal (TM) atoms. It is shown that the 4d TM dopings can not only produce new impurity energy bands in the band gap but also result in the semiconductor-metal phase transition. Consequently, the visible-light absorption is strongly strengthened due to the dopings of Y, Zr, Nb, Mo, and Ag, while it is only weakly improved for Tc, Ru, Rh, Pd, and Cd dopings. The improvement in visible-light absorption can be attributed to the intraband or interband transition of electrons. Moreover, the photocatalytic activities are explored, and we find Y and Ag dopings can effectively enhance the photocatalytic activity of TiO2(101) surface. Thus the mechanism of improving photocatalytic activity of TiO2(101) has been clearly addressed, which is beneficial to further experimental and theoretical researches on TiO2 photocatalysts
A promising catalytic solution of NO reduction by CO using g-C3N4/TiO2: A DFT study
The direct catalytic reduction of nitric oxide (NO) by carbon monoxide (CO) to form harmless N-2 and CO2 is an ideal strategy to simultaneously remove both these hazardous gases. To investigate the feasibility of using graphitic carbon nitride/titanium dioxide (g-C3N4/TiO2) to catalyze the NO reduction by CO, we systematically explore the effect of the interfacial coupling between g-C3N4 and TiO2 on the photo-induced carrier separation, the light absorption, and the surface reaction for the NO reduction by using density functional theory. The g-C3N4/TiO2 is predicted to have a better photocatalytic activity for NO reduction than g-C3N4, due to the enhanced light absorption intensity and the accelerated separation of the photo excited electron-hole pairs. By comparing the reaction routes on g-C3N4/TiO2 and g-C3N4, the results indicate that the introduction of TiO2 can keep the surface reaction process intact with the NO dissociation (N2O formation) being the rate-determining (crucial) step. Moreover, TiO2 can facilitate the desorption of NO reduction products, avoiding the deactivation of g-C3N4. This work shows that the composition of TiO2 into g-C3N4 provides a promising catalyst in NO reduction by CO. (C) 2021 Elsevier Inc. All rights reserved
Luminescence dating of holocene siliciclastic sediments in eastern Dahomey Basin, southwestern Nigeria
Several attempts at reconstructing geological settings and palaeoclimatic changes of the siliciclastic deposits of the Dahomey Basin, SW Nigeria, using relative age dating and correlation methods, have resulted in serious discrepancies on the ages. Therefore, a chronology framework established by an absolute age dating method is requisite to constrain the geological interpretation. This research focuses on quartz optically stimulated luminescence (OSL) dating of the upper siliciclastic sediments to help bridge the lacuna that arose from previous relative geologic dating. Ten sub-surface sediment samples were collected from the eastern part of the basin, and quartz OSL dating using single-aliquot regenerative-dose protocol was conducted for all the samples. The OSL signals appear well bleached prior to deposition and the OSL ages are reliable and robust. Through the application of OSL, the age framework of the uppermost part of sediments in the study area was established. The OSL dating results revealed that these depositional periods fall within the Holocene and are concentrated during two groups: 3.52 ka–1.55 ka, and 0.64 ka–0.05 ka. The samples with ages of 3.52 ka–1.55 ka distribute in the belt-like inland zone approximately parallel to the coastline. This deposition episode appears to be caused by the decrease in relative sea level during late Holocene. Thus, this study sheds light on the understanding past coast dynamics in the regio
Tuning surface-enhanced Raman scattering from graphene substrates using the electric field effect and chemical doping
The Arabidopsis RING Finger E3 Ligase RHA2b Acts Additively with RHA2a in Regulating Abscisic Acid Signaling and Drought Response1[C][W][OA]
We have previously shown that the Arabidopsis (Arabidopsis thaliana) RING-H2 E3 ligase RHA2a positively regulates abscisic acid (ABA) signaling during seed germination and postgerminative growth. Here, we report that RHA2b, the closest homolog of RHA2a, is also an active E3 ligase and plays an important role in ABA signaling. We show that RHA2b expression is induced by ABA and that overexpression of RHA2b leads to ABA-associated phenotypes such as ABA hypersensitivity in seed germination and seedling growth, enhanced stomatal closure, reduced water loss, and, therefore, increased drought tolerance. On the contrary, the rha2b-1 mutant shows ABA-insensitive phenotypes and reduced drought tolerance. We provide evidence showing that a rha2a rha2b-1 double mutant generally enhances ABA insensitivity of rha2b-1 in seed germination, seedling growth, and stomatal closure, suggesting that RHA2b and RHA2a act redundantly in regulating ABA responses. Genetic analyses support that, like RHA2a, the RHA2b action in ABA signaling is downstream of a protein phosphatase 2C, ABA-INSENSITIVE2 (ABI2), and in parallel with that of the ABI transcription factors ABI3/4/5. We speculate that RHA2b and RHA2a may have redundant yet distinguishable functions in the regulation of ABA responses
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