We prove that every strongly quasiconvex function is 2-supercoercive (in particular, coercive). Furthermore, we investigate the usual properties of proximal operators for strongly quasiconvex ...functions. In particular, we prove that the set of fixed points of the proximal operator coincides with the unique minimizer of a lower semicontinuous strongly quasiconvex function. As a consequence, we implement the proximal point algorithm for finding the unique solution of the minimization problem of a strongly quasiconvex function by using a positive sequence of parameters bounded away from 0 and, in particular, we revisit the general quasiconvex case. Moreover, a new characterization for convex functions is derived from this analysis. Finally, an application for a strongly quasiconvex function which is neither convex nor differentiable nor locally Lipschitz continuous is provided.
The main organic pollutants worldwide are pesticides, persistent chemicals that are of concern owing to their prevalence in various ecosystems. In nature, pesticide remainders are subjected to the ...chemical, physical, and biochemical degradation process, but because of its elevated stability and some cases water solubility, the pesticide residues persist in the ecosystem. The removal of pesticides has been performed through several techniques classified under biological, chemical, physical, and physicochemical process of remediation from different types of matrices, such as water and soil. This review provides a description of older and newer techniques and materials developed to remove specific pesticides according to previous classification, which range from bioremediation with microorganisms, clay, activated carbon, and polymer materials to chemical treatment based on oxidation processes. Some types of pesticides that have been removed successfully to large and small scale include, organophosphorus, carbamates, organochlorines, chlorophenols, and synthetic pyrethroids, among others. The most important characteristics, advantages, and disadvantages of techniques and materials for removing pesticides are described in this work.
In this paper, we provide a further study for nonconvex pseudomonotone equilibrium problems and nonconvex mixed variational inequalities by using global directional derivatives. We provide finer ...necessary and sufficient optimality conditions for both problems in the pseudomonotone case and, as a consequence, a characterization for a point to be a solution for nonconvex equilibrium problems is given. Finally, we apply the golden ratio algorithm for a class of nonconvex functions in equilibrium problems and mixed variational inequalities.
In this paper, we deal with two problems from the theory of nonconvex nonsmooth analysis; The characterization of nonsmooth quasiconvex functions, and connections between nonsmooth constraint ...optimization problems via variational inequalities. For the first problem, we provide different characterizations for nonsmooth quasiconvex functions, while for the second problem, a full connection between constraint optimization problems and Stampacchia and Minty variational inequalities is provided, in both cases, neither differentiability nor convexity nor continuity assumptions are considered. As a corollary, we recover well-known results from convex analysis.
Aims. This work aims at presenting the first two-dimensional models of an isolated rapidly rotating star that include the derivation of the differential rotation and meridional circulation in a ...self-consistent way. Methods. We use spectral methods in multidomains, together with a Newton algorithm to determine the steady state solutions including differential rotation and meridional circulation for an isolated non-magnetic, rapidly rotating early-type star. In particular we devise an asymptotic method for small Ekman numbers (small viscosities) that removes the Ekman boundary layer and lifts the degeneracy of the inviscid baroclinic solutions. Results. For the first time, realistic two-dimensional models of fast-rotating stars are computed with the actual baroclinic flows that predict the differential rotation and the meridional circulation for intermediate-mass and massive stars. These models nicely compare with available data of some nearby fast-rotating early-type stars like Ras Alhague (α Oph), Regulus (α Leo), and Vega (α Lyr). It is shown that baroclinicity drives a differential rotation with a slow pole, a fast equator, a fast core, and a slow envelope. The differential rotation is found to increase with mass, with evolution (here measured by the hydrogen mass fraction in the core), and with metallicity. The core-envelope interface is found to be a place of strong shear where mixing will be efficient. Conclusions. Two-dimensional models offer a new view of fast-rotating stars, especially of their differential rotation, which turns out to be strong at the core-envelope interface. They also offer more accurate models for interpreting the interferometric and spectroscopic data of early-type stars.
Context. Interpretation of interferometric observations of rapidly rotating stars requires a good model of their surface effective temperature. Until now, laws of the form ...\hbox{$T_\mathrm{eff}\propto g_\mathrm{eff}^\beta$}Teff∝geffβ have been used, but they are only valid for slowly rotating stars. Aims. We propose a simple model that can describe the latitudinal variations in the flux of rotating stars at any rotation rate. Methods. This model assumes that the energy flux is a divergence-free vector that is antiparallel to the effective gravity. Results. When mass distribution can be described by a Roche model, the latitudinal variations in the effective temperature only depend on a single parameter, namely the ratio of the equatorial velocity to the Keplerian velocity. We validate this model by comparing its predictions to those of the most realistic two-dimensional models of rotating stars issued from the ESTER code. The agreement is very good, as it is with the observations of two rapidly rotating stars, α Aql and α Leo. Conclusions. We suggest that as long as a gray atmosphere can be accepted, the inversion of data on flux distribution coming from interferometric observations of rotating stars uses such a model, which has just one free parameter.
In a randomized trial, the risk of mechanical ventilation or death among patients hospitalized with Covid-19 pneumonia (56.0% Hispanic or Latino, 14.9% Black, and 12.7% American Indian or Alaska ...Native) was 12.0% in the tocilizumab group and 19.3% in the placebo group. Tocilizumab did not increase survival.
Facile and low cost garlic clove extract based silver nanoparticles was synthesized and its broad spectrum of therapeutic activity including antibiofilm, antiparasitic and anti-breast cancer activity ...was evaluated. The synthesized garlic‑silver nanoparticles (G-AgNPs) were characterized by various physico-chemical techniques. G-AgNPs showed good optical property, highly crystalline nature, spherical shape and uniformly dispersed with size measuring between 10 and 50 nm. G-AgNPs have shown greater anti-bacterial and antibiofilm activity on clinically important pathogens methicillin-resistant S. aureus and P. aerigunosa at 100 μg ml−1. The efficacy of G-AgNPs against earthworm evidenced its effectiveness as anti-helminthic agent in treating intestinal parasites. The significant inhibition of BSA protein denaturation proves its anti-inflammatory property. In addition, G-AgNPs have shown remarkable anticancer effect and significantly inhibited the human breast cancer cell (MCF-7) viability at 100 μg ml−1 after 24 h. A noticeable change in the morphology of MCF-7 cells was also noticed. G-AgNPs were non-toxic to human HEK293 embryonic cells. Also, the non-toxic nature of G-AgNPs to C. cornuta and no morphological, physiological changes proved its safety to the environment. It is concluded that G-AgNPs have a broad range of biological applications and it can be used as an eco-friendly material without having negative effects in the environment.
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•Garlic clove extract coated silver nanoparticles (G-AgNPs) were synthesized and characterized.•G-AgNPs exhibited antibacterial and antibiofilm activity against P. aeruginosa at 100 μg/ml−1.•G-AgNPs showed anti-helminthic and anti-inflammatory.•G-AgNPs effectively controlled the proliferation of MCF-7 breast cancer cells.•G-AgNPs were non-toxic to C. cornuta and are environmentally safe.
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•Development time is minimized at intermediate protein to carbohydrate (P:C) ratios.•The highest P:C ratios confer maximum body/ovary size and survival.•Larvae regulate their nutrient ...intake towards intermediate P:C ratios.•Females lay their eggs in low P:C ratios.
Organisms from slime moulds to humans carefully regulate their macronutrient intake to optimize a wide range of life history characters including survival, stress resistance, and reproductive success. However, life history characters often differ in their response to nutrition, forcing organisms to make foraging decisions while balancing the trade-offs between these effects. To date, we have a limited understanding of how the nutritional environment shapes the relationship between life history characters and foraging decisions. To gain insight into the problem, we used a geometric framework for nutrition to assess how the protein and carbohydrate content of the larval diet affected key life history traits in the fruit fly, Drosophila melanogaster. In no-choice assays, survival from egg to pupae, female and male body size, and ovariole number – a proxy for female fecundity – were maximized at the highest protein to carbohydrate (P:C) ratio (1.5:1). In contrast, development time was minimized at intermediate P:C ratios, around 1:2. Next, we subjected larvae to two-choice tests to determine how they regulated their protein and carbohydrate intake in relation to these life history traits. Our results show that larvae targeted their consumption to P:C ratios that minimized development time. Finally, we examined whether adult females also chose to lay their eggs in the P:C ratios that minimized developmental time. Using a three-choice assay, we found that adult females preferentially laid their eggs in food P:C ratios that were suboptimal for all larval life history traits. Our results demonstrate that D. melanogaster larvae make foraging decisions that trade-off developmental time with body size, ovariole number, and survival. In addition, adult females make oviposition decisions that do not appear to benefit the larvae. We propose that these decisions may reflect the living nature of the larval nutritional environment in rotting fruit. These studies illustrate the interaction between the nutritional environment, life history traits, and foraging choices in D. melanogaster, and lend insight into the ecology of their foraging decisions.
In this paper, we use generalized asymptotic functions and second-order asymptotic cones to develop a general existence result for the nonemptiness of the proper efficient solution set and a ...sufficient condition for the domination property in nonconvex multiobjective optimization problems. A new necessary condition for a point to be efficient or weakly efficient solution is given without any convexity assumption. We also provide a finer outer estimate for the asymptotic cone of the weakly efficient solution set in the quasiconvex case. Finally, we apply our results to the linear fractional multiobjective optimization problem.
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