The paper is aimed at defining reduction, oxidation, and redox reactions based both on the oxidation number and charge changes in reacting species. It is rationalized that the processes of oxidation and reduction, usually occurring simultaneously, can occur also as independent processes. It is explained that in balancing chemical equations of redox reactions the “gain” or “loss” of electrons should be understood as changes in oxidation number. A formal expressions “+n e−” and “−n e−” represent in reality a (...) decrease and increase in oxidation number by n units, respectively. (shrink)

Protein redox reactions are one of the most basic and important biochemical actions. As amino acids are weak redox mediators, most protein redox functions are undertaken by protein cofactors, which include organic ligands and transition metal ions. Since both kinds of redox cofactors were available in the pre‐protein RNA world, it is challenging to explore which one was more involved in redox processes of primitive proteins? In this paper, using an examination of the redox (...) cofactor usage of putative ancient proteins, we infer that organic ligands participated more frequently than transition metals in redox reactions of primitive proteins, at least as protein cofactors. This is further supported by the relative abundance of amino acids in the primordial world. Supplementary material for this article can be found on the BioEssays website. BioEssays 30:766–771, 2008. © 2008 Wiley Periodicals, Inc. (shrink)

This paper compares two approaches that attempt to explain the origin of life, or biogenesis. The more established approach is one based on chemical principles, whereas a new, yet not widely known approach begins from a physical perspective. According to the first approach, life would have begun with—often organic—compounds. After having developed to a certain level of complexity and mutual dependence within a non-compartmentalised organic soup, they would have assembled into a functioning cell. In contrast, the second, physical type of (...) approach has life developing within tiny compartments from the beginning. It emphasises the importance of redox reactions between inorganic elements and compounds found on two sides of a compartmental boundary. Without this boundary, “ life ” would not have begun, nor have been maintained; this boundary—and the complex cell membrane that evolved from it—forms the essence of life. (shrink)

This paper compares two approaches that attempt to explain the origin of life, or biogenesis. The more established approach is one based on chemical principles, whereas a new, yet not widely known approach begins from a physical perspective. According to the first approach, life would have begun with—often organic—compounds. After having developed to a certain level of complexity and mutual dependence within a non-compartmentalised organic soup, they would have assembled into a functioning cell. In contrast, the second, physical type of (...) approach has life developing within tiny compartments from the beginning. It emphasises the importance of redox reactions between inorganic elements and compounds found on two sides of a compartmental boundary. Without this boundary, “life” would not have begun, nor have been maintained; this boundary—and the complex cell membrane that evolved from it—forms the essence of life. (shrink)

Rho GTPases are critically important and are centrally positioned regulators of the actomyosin cytoskeleton. By influencing the organization and architecture of the cytoskeleton, Rho proteins play prominent roles in many cellular processes including adhesion, migration, intra‐cellular transportation, and proliferation. The most important method of Rho GTPase regulation is via the GTPase cycle; however, post‐translational modifications (PTMs) also play critical roles in Rho protein regulation. Relative to other PTMs such as lipidation or phosphorylation that have been extensively characterized, protein oxidation is (...) a regulatory PTM that has been poorly studied. Protein oxidation primarily occurs from the reaction of reactive oxygen species (ROS), such as hydrogen peroxide (H2O2), with amino acid side chain thiols on cysteine (Cys) and methionine (Met) residues. The versatile redox modifications of cysteine residues exemplify their integral role in cell signalling processes. Here we review prominent members of the Rho GTPase family and discuss how lipidation, phosphorylation, and oxidation on conserved cysteine residues affects their regulation and function. (shrink)

In many cells, a nitric oxide (NO) synthase inducible by immunological stimuli produces a sustained flow of NO that lasts a long time. NO is a short‐lived molecule but it is a diffusibel ligand believed to be capable of reaching distal target sites. Further, several lines of evidence indicate that cysteine‐rich motifs of metal‐binding proteins, as well as redox‐sensitive metal clusters of metalloproteins, are natural sensors of bioradicals like NO. In metalloregulatory proteins, metals are often conveniently located at binding (...) sites and bound to cysteine residues. Accordingly, disruption of the metal‐thiolate polymetallic clusters should trigger significant remodelling of the protein structure involved in regulation. We can therefore postulate that the nitrosation reaction occurring at metal centres or cysteine‐rich motifs will preclude correct binding to regulatory sites. Several examples are given of metalloregulatory proteins whose metal is bound to thiols and may then become sensitive to NO. Recent observations indicate that in response to NO synthesis, iron regulatory protein, a eukaryotic bifunctional [Fe‐S] protein, switches from acting as aconitase to being an RNA‐binding regulator, and we suggest that the interplay between NO or a NO‐derived molecule and metal clusters at critical allosteric sites may be a crucial component of the cellular response to environmental stress. (shrink)

The environment can elicit biological responses such as oxidative stress (OS) and inflammation as a consequence of chemical, physical, or psychological changes. As population studies are essential for establishing these environment-organism interactions, biomarkers of OS or inflammation are critical in formulating mechanistic hypotheses. By using examples of stress induced by various mechanisms, we focus on the biomarkers that have been used to assess OS and inflammation in these conditions. We discuss the difference between biomarkers that are the result of a (...) chemical reaction (such as lipid peroxides or oxidized proteins that are a result of the reaction of molecules with reactive oxygen species) and those that represent the biological response to stress, such as the transcription factor NRF2 or inflammation and inflammatory cytokines. The high-throughput and holistic approaches to biomarker discovery used extensively in large-scale molecular epidemiological exposome are also discussed in the context of human exposure to environmental stressors. We propose to consider the role of biomarkers as signs and to distinguish between signs that are just indicators of biological processes and proxies that one can interact with and modify the disease process. (shrink)

The Rashomon effect – a phenomenon studied in the arts and social sciences – occurs when the same event is given contradictory interpretations by different individuals involved. The effect was named after Akira Kurosawa's 1950 film Rashomon, in which a murder is described in four contradictory ways by four witnesses. In the film, a samurai has been killed under mysterious circumstances. Four people give contradictory reports about the crime. In particular, the samurai's wife claims that she was sexually abused by (...) a bandit, fainted, and then awoke to find her husband dead; the bandit claims that he seduced the wife and challenged the samurai in a battle to victory or at least to an honorable death; the woodcutter (who may have been an onlooker) claims that he witnessed the rape and murder but was not involved; and the dead samurai's spirit claims that he committed suicide. The Rashomon effect is not only about constructing different versions of the world based on differences in perspective; it occurs when such differences appear together with the absence of evidence to assess any version of the truth, plus “the social pressure for closure on the question.” In this commentary, we describe the relevance of the Rashomon effect beyond the arts and social sciences, namely in the field of biology. We use examples from redox biology, which is full of contradictions, thus making it fertile ground on which to apply reasoning derived from the Rashomon effect. (shrink)

In this article, we discuss a hypothesis to explain the preferential synthesis of the superoxide sensitive form of aconitase in mitochondria and the phenotype observed in manganese superoxide dismutase mutant mice, which show a gross over accumulation of stored fat in liver. The model proposes that intermediary metabolism is redox regulated by mitochondrial superoxide generated during mitochondrial respiration. This regulates the level of reducing equivalents (NADH) entering the electron transport chain (ETC) through the reversible inactivation of mitochondrial aconitase. This (...) control mechanism has a dual function; firstly, it regulates levels of superoxide generated by the ETC and, secondly, it fine‐tunes metabolism by channeling citrate either for the production of NADH for energy metabolism or diverting it for the synthesis of fats. In this setting, the mitochondrial redox state influences metabolic decisions via a superoxide–aconitase rheostat. BioEssays 26:894–900, 2004. © 2004 Wiley Periodicals, Inc. (shrink)

Ultradian rhythms are those that cycle many times in a day and are therefore measured in hours, minutes, seconds or even fractions of a second. In yeasts and protists, a temperature‐compensated clock with a period of about an hour (30–90 minutes) provides the time base upon which all central processes are synchronized. A 40‐minute clock in yeast times metabolic, respiratory and transcriptional processes, and controls cell division cycle progression. This system has at its core a redox cycle involving NAD(P)H (...) and dithiol–disulfide interconversions. It provides an archetype for biological time keeping on longer time scales (e.g. the daily cycles driven by circadian clocks) and underpins these rhythms, which cannot be understood in isolation. Ultradian rhythms are the foundation upon which the coherent functioning of the organism depends. BioEssays 29:465–473, 2007. © 2007 Wiley Periodicals, Inc. (shrink)

Behavioral intervention techniques leveraging reactive responses have gained popularity as tools for promoting ethical behavior. Choice architects, for example, design and present default opt-out options to nudge individuals into accepting preselected choices deemed beneficial to both the decision-maker and society. Such interventions can also employ mild financial incentives or affective triggers including joy, fear, empathy, social pressure, and reputational rewards. We argue, however, that ethical competence is achieved via reflection, and that heavy reliance on reactive behavioral interventions can undermine the (...) development of ethical competence over the long term. Specifically, drawbacks may occur through motivational displacement, dependency, moral crowding out, loss of personal autonomy, and reactance. We introduce complementary cognitive boosting techniques designed to stimulate reflective cognition, as a more promising long-term strategy for instilling ethical behavior. One such approach is the Moral Self-Awareness (MSA) motivational construct, which incrementally leads agents to increasing levels of ethical reflection. We explain why ethical boosting approaches present more edifying and durable alternatives to reactive behavioral interventions and offer suggestions for social and organizational policy. (shrink)

St. Thomas Aquinas has always considered intelligence a potency higher than the will, absolutely speaking. That being said, and in my view, the existential primacy of the will in the act of freedom (particularly in choosing the existential end) is also indisputably Thomistic, as Cornelio Fabro has shown. This paper endeavors to explain Aquinas' doctrine on the absolute primacy of the intellect and thus show that these two primacies can be affirmed coherently, that is, the intellect’s absolute primacy and the (...) will’s existential primacy. Firstly, I will explain the reasoning St. Thomas Aquinas uses in the Summa to justify the absolute primacy of the intellect over the will. Secondly, I will explore some parallel texts, in order to shed light on my interpretation of the Summa and expand our view regarding this and related doctrinal points. Thirdly, I will offer a brief study of Fabro’s position, one in which his concerns regarding the intellect’s absolute primacy are taken into account and carefully considered. (shrink)

Early in the 20th century, Charles Manning Child attributed organismal gradients in metabolism to interactions among groups of cells. Metabolic gradients are now firmly grounded in redox chemistry, yet modern work on metabolic signaling has consistently focused on the cellular level. Multicellular redox regulation, however, may occur when redox state is determined by the behavior of a group of cells. For instance, typically an abundance of substrate will shift the redox state of mitochondria in the direction (...) of reduction, leading to increased reactive oxygen species (ROS). These ROS, in turn, may modify the conformation and activity of proteins involved in signaling pathways, resulting in phenotypic changes. In contrast, if substrate triggers the contractions of a muscular structure comprising mitochondrion‐rich cells, the resulting metabolic demand may shift the redox state in the direction of oxidation, with a corresponding decrease of ROS and different phenotypic effects. Indeed, colonial hydroids exemplify this process. Parallel examples may occur whenever mitochondria are concentrated in cells of structures that can respond to environmental perturbations with increased metabolic demand. In these circumstances, predicting the direction of metabolic signaling may require an understanding of events at the organismal level. BioEssays 28:72–77, 2006. © 2005 Wiley Periodicals, Inc. (shrink)

Using a signaling framework, we argue that ethical behavior as evidenced by charitable donations is viewed more positively by investors when seen not to be based on self-serving motives but rather on authentic generosity that builds moral capital. The affirmed religiosity of CEOs may make their ethical position more credible, while their embeddedness within a family business suggests that CEOs are backed by powerful owners with long-time horizons and a desire to build moral capital with stakeholders. We find in a (...) study of market responses to 1572 corporate donations by S&P 1500 firms that financial markets react more positively to charitable initiatives from firms with religion-declared CEOs, but only if these are family businesses. (shrink)

Gut Reactions is an interdisciplinary defense of the claim that emotions are perceptions of changes in the body.

In his political philosophy, John Rawls has a normative notion of reasonable behaviour expected of citizens in a pluralist society. We interpret the various strands of this idea and introduce them to the discourse on stakeholder dialogue in order to address two shortcomings in the latter. The first shortcoming is an unnoticed, artificial separation of words from actions which neglects the communicative power of action. Second, in its proposed new role of the firm, the discourse of political CSR appeared to (...) offer a promising synthesis of deliberation and action. However, the discourse has been criticized for its shortcoming in failing to provide a regulatory environment for corporation—stakeholder dialogue. Through our interpretation of Rawls’ notion of reasonableness in citizens, the article makes two important theoretical contributions to the debate on stakeholder dialogue. First, we transfer Rawls’ injunction in insisting that dialogues between business corporations and their weaker stakeholders must be understood as consisting of both verbal exchanges and actions. Second, we propose that the coercive power of government ought to provide a necessary context for stakeholder dialogue, and that by doing so, it can provide a way forward for the discourse of political CSR. We illustrate the usefulness of this contribution from Rawls in an analysis of BP’s behaviour towards thousands of victims following the Deepwater Horizon blowout in 2010. (shrink)

Since the late 1990s, the number of apologies being offered by CEOs of large companies has exploded. Communication and management scholars have analyzed whether and why some of these apologies are more effective or more ethical than others. Most of these analyses, however, have remained at the anecdotal level. Moreover, the practical, economic consequences of apologies have not been examined. Almost no rigorous or systematic empirical work exists that examines whether stakeholders reward firms whose CEOs give apologies that are more, (...) rather than less, ethical; and punish firms whose corporate apologies are not ethically sound. This lacuna is surprising given that the whole purpose of an apology is to restore trust between the apologizer and the recipients of the apology. It is also surprising, given that stock market participants do appear, in at least some cases, to evaluate and respond to apologies by CEOs. When Johnson and Johnson was hit by the Tylenol poisonings, its stock price plummeted. One day after CEO James Burke’s apology—an apology widely praised for being ethically sound—approximately a half billion dollars of its previously lost stock value was restored. It appears, then, that a good CEO apology may lead to an increased stock value ceteris paribus. But is the Johnson and Johnson case representative of how the market responds in general to CEO apologies? (shrink)

This text constitutes a reflection on politics, women, feminism and the future in the current global crisis. The civilizing crisis is total, universal and unstoppable. Here we try to sketch some ideas of what I think is really at stake: the definition of subject, person and rights, the idea of the future desirable society, and the foundations and regulation of social life, the concept of good life. In the context of an escalating global crisis and the growing feeling of being (...) in transition to nowhere, the question of whether the arrival of this new order will resist our rights is vital, ethical and politically fundamental. This document tries to collaborate with the process of answering it. The order of the world to come is being built today, in increasingly adverse conditions for the rights and freedoms of women and it is important to anticipate the reflection on some of its foreseeable consequences. (shrink)

Processing the motivational relevance of a visual scene and reacting accordingly is crucial for survival. Previous work suggests the emotional content of naturalistic scenes affects response speed, such that unpleasant content slows responses whereas pleasant content accelerates responses. It is unclear whether these effects reflect motor-cognitive processes, such as attentional orienting, or vary with the function/outcome of the motor response itself. Four experiments manipulated participants’ ability to terminate the picture and, thereby, the response’s function and motivational value. Attentive orienting was (...) manipulated via picture repetition, which diminishes orienting. A total of N = 81 participants completed versions of a go/no-go task, discriminating between distorted versus intact pictures drawn from six content categories varying in positive, negative, or neutral valence. While all participants responded faster with repetition, only participants without offset control exhibited slower responses to unpleasant and accelerated responses to pleasant content. Emotional engagement, measured by the late positive potential, was not modulated by attentional orienting, suggesting that the interaction between repetition and offset control is not due to altered emotional engagement. Together, results suggest that response time changes as a function of emotional content and sensitivity to attention orienting depends on the motivational function of the motor response. (shrink)