Hybrid evolutionary oligopolies and the dynamics of corporate social responsibility

The diffusion of corporate social responsibility is investigated by employing a hybrid evolutionary game where a firm chooses between being either socially responsible, which implies devoting a fraction of its profit to social projects, or non-socially responsible. Consumers prize socially responsible companies by paying a higher reservation price for their products. The hybrid evolutionary framework is characterized by a quantity dynamics that describes the oligopolistic competition given firms’ belief about the composition of the industry. At regular intervals of time, this belief is endogenously updated by a retrospective comparison on the profits obtained and on the basis of an evolutionary mechanism. Assuming that firms are Nash players, that is at each instant of time they produce the Nash equilibrium-in-belief quantity, the investigation of the model reveals that an industry homogeneously populated by socially responsible firms is a stable equilibrium when the fraction of profits earmarked for socially responsible activities is sufficiently limited. However, the extra marginal profits of a socially responsible firm are reduced when the number of competitors increases, impeding the diffusion of socially responsible companies. In particular, the trade-off between a higher net margin on sales obtained by socially responsible firms and a lower level of production that reduces the profit gap between a socially responsible firm and the rest of the market shows that an increased size of the industry favors mixed oligopolies. Moreover, imposing the hypothesis of neutrality of CSR activities, the model reveals that being socially responsible is an evolutionarily stable strategy for firms and is convenient for customers. Relaxing the hypothesis of Nash players by introducing boundedly rational firms that decide their level of production according to a partial adjustment toward the best reply, the robustness of these results is confirmed

Ocean warming and acidification detrimentally affect coral tissue regeneration at a Mediterranean CO2 vent

Among the main phenomena that are causing significant changes in ocean waters are warming and acidification, largely due to anthropogenic activities. Growing evidence suggests that climate change is having more substantial and rapid effects on marine communities than on terrestrial ones, triggering several physiological responses in these organisms, including in corals. Here we investigated, for first time in the field, the combined effect of increasing seawater acidification and warming on tissue regeneration rate of three Mediterranean scleractinian coral species characterized by different trophic strategies and growth modes. Balanophyllia europaea (solitary, zooxanthellate), Leptopsammia pruvoti (solitary, non-zooxanthellate) and Astroides calycularis (colonial, non-zooxanthellate) specimens were transplanted, during a cold, intermediate, and warm period, along a natural pH gradient generated by an underwater volcanic crater at Panarea Island (Mediterranean Sea, Italy), characterized by continuous and localized CO2 emissions at ambient temperature. Our results show a decrease in regenerative capacity, especially in the zooxanthellate species, with increasing seawater temperature and acidification, with demonstrated species-specific differences. This finding suggests that increasing seawater temperature and acidification could have a compounding effect on coral regeneration following injury, potentially hindering the capacity of corals to recover following physical disturbance under predicted climate change

TSO/DSO Coordination for RES Integration: A Systematic Literature Review

Data Availability Statement: Not applicable.Copyright: © 2022 by the authors. The increasing penetration of large-scale Renewable Energy Sources (RESs) has raised several challenges for power grid operation. Power management solutions supporting the integration of RESs, such as those based on energy storage technologies, are generally costly. Alternatively, promoting a more proactive role of the Distribution System Operator (DSO) to successfully manage RESs’ uncertainty, and take advantage of their flexible resources for the provision of ancillary services, can avoid installing expensive devices in the network and reduce costs. In this line, improved coordination between Transmission System Operators (TSOs) and DSOs is highly desirable. In this paper, the feasibility of solving different aspects of the integration of RESs through an improved TSO/DSO coordination is evaluated. In particular, a Systematic Literature Review (SLR) is conducted to study the most relevant TSO/DSO coordination approaches, exclusively focused on integrating distributed RESs, currently available in the literature. Their main operational, managerial, economic, and computational challenges, advantages, and disadvantages are discussed in detail to identify the most promising research trends and the most concerning research gaps to pave the way for future research toward developing a solid TSO/DSO coordination mechanism for integrating RESs efficiently. The main results of the SLR show a clear trend in implementing decentralized TSO/DSO coordination models since they provide efficient facilitation of RESs’ services, while reducing computational burden and communication complexity and, consequently, reducing operative costs. In addition, while different aspects of the TSO/DSO coordination implementation, such as reactive power and voltage regulation, operational cost minimization, operational planning, and congestion management, have been thoroughly addressed in the literature, further research is needed regarding data exchange mechanisms and RESs’ uncertainty modeling and prediction. In this line, the development of standardized communication solutions, based on the Common Grid Model Exchange Standard (CGMES) of the International Electrotechnical Commission (IEC), has shown promising interoperability results, whereas the use of learning-based approaches to predict RESs’ uncertain behavior and distribution networks’ responses, using only historical data, which relieves the need for access to commercially sensitive and proprietary network data, has also shown itself to be a promising research directionThis research received no external funding

Renewable energy sources integration via machine learning modelling: A systematic literature review

The use of renewable energy sources (RESs) at the distribution level has become increasingly appealing in terms of costs and technology, expecting a massive diffusion in the near future and placing several challenges to the power grid. Since RESs depend on stochastic energy sources —solar radiation, temperature and wind speed, among others— they introduce a high level of uncertainty to the grid, leading to power imbalance and deteriorating the network stability. In this scenario, managing and forecasting RES uncertainty is vital to successfully integrate them into the power grids. Traditionally, physical- and statistical-based models have been used to predict RES power outputs. Nevertheless, the former are computationally expensive since they rely on solving complex mathematical models of the atmospheric dynamics, whereas the latter usually consider linear models, preventing them from addressing challenging forecasting scenarios. In recent years, the advances in machine learning techniques, which can learn from historical data, allowing the analysis of large-scale datasets either under non-uniform characteristics or noisy data, have provided researchers with powerful data-driven tools that can outperform traditional methods. In this paper, a systematic literature review is conducted to identify the most widely used machine learning-based approaches to forecast RES power outputs. The results show that deep artificial neural networks, especially long-short term memory networks, which can accurately model the autoregressive nature of RES power output, and ensemble strategies, which allow successfully handling large amounts of highly fluctuating data, are the best suited ones. In addition, the most promising results of integrating the forecasted output into decision-making problems, such as unit commitment, to address economic, operational and managerial grid challenges are discussed, and solid directions for future research are provided

Phenolic characterization and antioxidant activity of two endemic wormwood species of Morocco: Artemisia ifranensis J. Didier and Artemisia mesatlantica

Artemisia ifranensis and Artemisia mesatlantica are two endemic species in Morocco belonging to the Asteraceae family. Located in the region of Moroccan Atlas, they are very much sought after by the local population for their therapeutic properties.However, given the limited studies conducted on these species and in order to contribute to their valorization, we selected them in full bloom in the region of Timahdite for a phytochemical study and an evaluation of their antioxidant properties. The results of phytochemical screening revealed their richness in polyphenols, sterols, triterpenes and mucilages. The extraction yields of the total polyphenols by maceration in a methanol-water mixture (80/20) were 10.10% for A. mesatlantica and 16.66% for A. ifranensis. The determination of the total phenols by the Folin-Ciocalteu method after fractionation of the polyphenolic extracts showed the abundance of these compounds in the butanolic fraction of A. Mesatlantica and the methanolic extract of A. Ifranensis. For the total flavonoids dosed with aluminum trichloride, the ethyl acetate fractions of A. Mesatlantica and butanolic acid. Ifranensis were the richest. In addition, the crude extract of A. Mesatlantica was particularly rich in condensed tannins.Evaluation of the antioxidant activity by reduction of iron (FRAP) and trapping of the free radical DPPH * showed that all the extracts have a moderate antioxidant power.These early studies on A. mesatlantica and A. ifranensis of Timahdite reveal their abundance of important chemical compounds. Also, due to the ability of these plants to trap radicals, they can be considered as sources of natural antioxidants

Pathways to ensure universal and affordable access to hepatitis C treatment

Direct-acting antivirals (DAAs) have dramatically changed the landscape of hepatitis C treatment and prevention. The World Health Organization has called for the elimination of hepatitis C as a public health threat by 2030. However, the discrepancy in DAA prices across low-, middle- and high-income countries is considerable, ranging from less than US$100 to approximately US$ 40,000 per course, thus representing a major barrier for the scale-up of treatment and elimination. This article describes DAA pricing and pathways to accessing affordable treatment, providing case studies from Australia, Egypt and Portugal. Pathways to accessing DAAs include developing comprehensive viral hepatitis plans to facilitate price negotiations, voluntary and compulsory licenses, patent opposition, joint procurement, and personal importation schemes. While multiple factors influence the price of DAAs, a key driver is a country's capacity and willingness to negotiate with pharmaceutical companies. If negotiations do not lead to a reasonable price, governments have the option to utilise flexibilities outlined in the Agreement on Trade-Related Aspects of Intellectual Property Rights. Affordable access to DAAs is underpinned by collaboration between government, civil society, global organisations and pharmaceutical companies to ensure that all patients can access treatment. Promoting these pathways is critical for influencing policy, improving access to affordable DAAs and achieving hepatitis C elimination

Nitric oxide availability is increased in contracting skeletal muscle from aged mice, but does not differentially decrease muscle superoxide

Reactive oxygen and nitrogen species have been implicated in the loss of skeletal muscle mass and function that occurs during aging. Nitric oxide (NO) and superoxide are generated by skeletal muscle and where these are generated in proximity their chemical reaction to form peroxynitrite can compete with the superoxide dismutation to hydrogen peroxide. Changes in NO availability may therefore theoretically modify superoxide and peroxynitrite activities in tissues, but published data are contradictory regarding aging effects on muscle NO availability. We hypothesised that an age-related increase in NO generation might increase peroxynitrite generation in muscles from old mice, leading to an increased nitration of muscle proteins and decreased superoxide availability. This was examined using fluorescent probes and an isolated fiber preparation to examine NO content and superoxide in the cytosol and mitochondria of muscle fibers from adult and old mice both at rest and following contractile activity. We also examined the 3-nitrotyrosine (3-NT) and peroxiredoxin 5 (Prx5) content of muscles from mice as markers of peroxynitrite activity. Data indicate that a substantial age-related increase in NO levels occurred in muscle fibers during contractile activity and this was associated with an increase in muscle eNOS. Muscle proteins from old mice also showed an increased 3-NT content. Inhibition of NOS indicated that NO decreased superoxide bioavailability in muscle mitochondria, although this effect was not age related. Thus increased NO in muscles of old mice was associated with an increased 3-NT content that may potentially contribute to age-related degenerative changes in skeletal muscle

The chemistry of C3 & Carbon Chain Molecules in DR21(OH)

(Abridged) We have observed velocity resolved spectra of four ro-vibrational far-infrared transitions of C3 between the vibrational ground state and the low-energy nu2 bending mode at frequencies between 1654--1897 GHz using HIFI on board Herschel, in DR21(OH), a high mass star forming region. Several transitions of CCH and c-C3H2 have also been observed with HIFI and the IRAM 30m telescope. A gas and grain warm-up model was used to identify the primary C3 forming reactions in DR21(OH). We have detected C3 in absorption in four far-infrared transitions, P(4), P(10), Q(2) and Q(4). The continuum sources MM1 and MM2 in DR21(OH) though spatially unresolved, are sufficiently separated in velocity to be identified in the C3 spectra. All C3 transitions are detected from the embedded source MM2 and the surrounding envelope, whereas only Q(4) & P(4) are detected toward the hot core MM1. The abundance of C3 in the envelope and MM2 is \sim6x10^{-10} and \sim3x10^{-9} respectively. For CCH and c-C3H2 we only detect emission from the envelope and MM1. The observed CCH, C3, and c-C3H2 abundances are most consistent with a chemical model with n(H2)\sim5x10^{6} cm^-3 post-warm-up dust temperature, T_max =30 K and a time of \sim0.7-3 Myr. Post warm-up gas phase chemistry of CH4 released from the grain at t\sim 0.2 Myr and lasting for 1 Myr can explain the observed C3 abundance in the envelope of DR21(OH) and no mechanism involving photodestruction of PAH molecules is required. The chemistry in the envelope is similar to the warm carbon chain chemistry (WCCC) found in lukewarm corinos. The observed lower C3 abundance in MM1 as compared to MM2 and the envelope could be indicative of destruction of C3 in the more evolved MM1. The timescale for the chemistry derived for the envelope is consistent with the dynamical timescale of 2 Myr derived for DR21(OH) in other studies.Comment: 11 Pages, 6 figures, accepted for publication in A&

Paradoxical roles of antioxidant enzymes:Basic mechanisms and health implications

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are generated from aerobic metabolism, as a result of accidental electron leakage as well as regulated enzymatic processes. Because ROS/RNS can induce oxidative injury and act in redox signaling, enzymes metabolizing them will inherently promote either health or disease, depending on the physiological context. It is thus misleading to consider conventionally called antioxidant enzymes to be largely, if not exclusively, health protective. Because such a notion is nonetheless common, we herein attempt to rationalize why this simplistic view should be avoided. First we give an updated summary of physiological phenotypes triggered in mouse models of overexpression or knockout of major antioxidant enzymes. Subsequently, we focus on a series of striking cases that demonstrate “paradoxical” outcomes, i.e., increased fitness upon deletion of antioxidant enzymes or disease triggered by their overexpression. We elaborate mechanisms by which these phenotypes are mediated via chemical, biological, and metabolic interactions of the antioxidant enzymes with their substrates, downstream events, and cellular context. Furthermore, we propose that novel treatments of antioxidant enzyme-related human diseases may be enabled by deliberate targeting of dual roles of the pertaining enzymes. We also discuss the potential of “antioxidant” nutrients and phytochemicals, via regulating the expression or function of antioxidant enzymes, in preventing, treating, or aggravating chronic diseases. We conclude that “paradoxical” roles of antioxidant enzymes in physiology, health, and disease derive from sophisticated molecular mechanisms of redox biology and metabolic homeostasis. Simply viewing antioxidant enzymes as always being beneficial is not only conceptually misleading but also clinically hazardous if such notions underpin medical treatment protocols based on modulation of redox pathways