Toxicity Mechanisms of ZnO Nanoparticles in Nanochloropsis Oculata with a Comparative Approach with CuO and Ag Nanoparticles

The purpose of present work was the investigation of different concentrations of zinc oxide nanoparticles on the marine microalga Nannochloropsis oculata and compare the results of this study with previous studies. Dissolution of ZnO NPs in nanopure water was 0.378-3.12 mg/L and the rate solubility decreased with increasing the concentrations of ZnO NPs. ZnO NPs were toxic to this microalga with EC50 of 153/72 mg/L. The toxicity of 200 mg/L ZnO NPs was 59.36% for the cell number, 61.27% for MTT test, and 57.34% for the chlorophyll content. Increase the content of malondialdehyde and hydrogen peroxide in response to increasing the concentration of ZnO NPs was indicated the induction of oxidative stress in N. oculata. The activity of catalase and lactate dehydrogenase increased in the treated cells, while the activity of ascorbate peroxidase was decreased. Concurrently, an increase in the content of carotenoids and phenolic compounds was observed in the treated cells. SEM and TEM analyses confirmed the aggregation of algal cells, damages in cell membrane and atypical changes in morphology of cell wall after NPs treatments. The FTIR results cofirmed the interaction of ZnO NPs with C-H, C-O and C=O groups on the cell surface. All of these changes were indicated the significant toxic impacts of ZnO NPs on the N. oculata cells. Comparison between the results obtained in previous studies with our results showed that the defensive mechanisms of N. oculata probably was not effective against the oxidative stress by >10 mg/L of ZnO NPs, > 5 mg/L of CuO NPs and > 1 mg/L of Ag NPs. Therefore, N. oculata is sensitive to such concentrations of these NPs.

Why Perpetrators and Innocent Victims are Sometimes Harshly judged? Belief in a Just World and Other Situational Determinants

Although Belief in a Just World (BJW) has positive influences on well-being, the attempts to maintain these beliefs may give rise to awry judgments in contexts of harm. In a scenario-based study, we examined the associations of general belief in a just world (GBJW) with BJW maintenance strategies, including victim blaming, victim derogation, perpetrator demonization, and compensation. We hypothesized that because these harsh judgments about victims and offenders along with compensation are used as defensive mechanisms against threats to BJW, using a specific strategy depends on the availability of each strategy and the level of a person’s GBJW. Thus, we also tested whether GBJW and situational cues for victim’s respectability and perpetrator’s evilness have interaction effects on various strategies to defend BJW. By manipulating the characteristics of the victim (professor vs. car dealer) and offender (with evilness cues vs. without evilness cues) in a crime scenario, the interaction effects on judgments about victims and perpetrators as well as compensation were investigated. The results indicated that while GBJW interacted with victim’s respectability and perpetrator’s evilness to predict demonization and derogation, there was no three-way interaction and two-way interaction effects between victim’s respectability and perpetrator’s evilness on the four BJW-maintenance strategies. Taken together, our findings highlight the nuanced effects of just world beliefs on how people react to and make sense of violent incidents.

Mobbing Syndrome as a Personality Disorder: The Consequences of Complicated Socialisation in the Symptoms of Occupational Destruction

The relevance of this study is conditioned by the need to identify the key preconditions and causes of increased violence in the workplace to find new methods of combating mobbing at both international and national levels. The purpose of this study is to analyse mobbing as a psychosocial and medical phenomenon, which is logical to consider with the symptoms of professional destruction. The study of mobbing syndrome took place in two stages based on synergetic methodology using such general scientific research methods as analysis, synthesis, comparison, and systematisation. The study identified the specific features of mobbing at the Ukrainian and world level. The authors considered the main causes of mobbing behaviour as a social issue, as a social phenomenon of the organisation, and as a form of collective violence. The study provides reasoning regarding the necessity of studying the mobbing syndrome from the standpoint of psychosocial and medical aspects. The authors analysed fractal dynamics of mobbing formation, presented in somatogenesis, psychogenesis, and sociogenesis. The study presents the main predictors of professional destruction, which include individual-personal, i.e., total control, manipulation, and conflict, etc., and clinical, which include emotional instability, narcissism, steroidism, and more. It is determined that the types of individual's socialisation develop in accordance with the defensive mechanisms that prevail upon restoring one's security. The study considered the specific features of the clinical aspect of personality disorder. The authors provided a general description of the narcissistic type of personality disorder as a structure of mobster. The practical value of this study lies in the interdisciplinary investigation of mobbing syndrome based on psychosocial and methodological factors

Cellular Defensive Mechanisms of Tea Polyphenols: Structure-Activity Relationship

Tea is particularly rich in polyphenols, including catechins and theaflavins, thearubigins, flavonols, and phenolic acids, which are believed to contribute to the health benefits of tea. The health-promoting effects of tea polyphenols are believed to be related to their cellular defensive properties. This review is intended to briefly summarize the relationship between the chemical structures of tea polyphenols and their biological activities. Tea polyphenols appear as direct antioxidants by scavenging reactive oxygen/nitrogen species; chelating transition metals; and inhibiting lipid, protein, and DNA oxidations. They also act directly by suppressing “pro-oxidant” enzymes, inducing endogenous antioxidants, and cooperating with vitamins. Moreover, tea polyphenols regulate cellular signaling transduction pathways, importantly contributing to the prevention of chronic diseases and the promotion of physiological functions. Apparently, the features in the chemical structures of tea polyphenols are closely associated with their antioxidant potentials.

Phylogenomics illuminates the evolution of bobtail and bottletail squid (order Sepiolida)

Bobtail and bottletail squid are small cephalopods with striking anti-predatory defensive mechanisms, bioluminescence, and complex morphology; that inhabit nektobenthic and pelagic environments around the world’s oceans. Yet, the evolution and diversification of these animals remain unclear. Here, we used shallow genome sequencing of thirty-two bobtail and bottletail squids to estimate their evolutionary relationships and divergence time. Our phylogenetic analyses show that each of Sepiadariidae, Sepiolidae, and the three subfamilies of the Sepiolidae are monophyletic. We found that the ancestor of the Sepiolinae very likely possessed a bilobed light organ with bacteriogenic luminescence. Sepiolinae forms a sister group to Rossinae and Heteroteuthinae, and split into Indo-Pacific and Atlantic-Mediterranean lineages. The origin of these lineages coincides with the end of the Tethys Sea and the separation of these regions during the Eocene and the beginning of the Oligocene. We demonstrated that sepiolids radiated after the Late Cretaceous and that major biogeographic events might have shaped their distribution and speciation.

Evolutionary dynamics shape two passive defensive mechanisms in Neotropical snake radiations

We mapped the distribution of two defensive behaviors (balling and head hiding) of Neotropical snakes to evaluate its distribution in distinct phylogenetic groups. Balling behavior was observed in 58 out of the 167 examined species across seven families. Head hiding was observed in a total of 100 species across nine families. From the high prevalence of balling behavior in basal groups of snakes, such as Anomalepididae, Boidae, Leptotyphlopidae, Tropidophiidae, and Typhlopidae, and the low prevalence among species of recent diversification radiations, such as Elapidae and Viperidae, we suggest that this behavior evolved in basal groups and persisted in some derived taxa. Balling was not observed in association with other defensive strategies, while head hiding can occur in combination with caudal elevation, caudal vibration, and body flattening. Therefore, head hiding, in contrast to balling behavior, presents itself as putatively more flexible, as it should allow for an escalated degree of defensive displays.

Interception of automated adversarial drone swarms in partially observed environments

As the prevalence of drones increases, understanding and preparing for possible adversarial uses of drones and drone swarms is of paramount importance. Correspondingly, developing defensive mechanisms in which swarms can be used to protect against adversarial Unmanned Aerial Vehicles (UAVs) is a problem that requires further attention. Prior work on intercepting UAVs relies mostly on utilizing additional sensors or uses the Hamilton-Jacobi-Bellman equation, for which strong conditions need to be met to guarantee the existence of a saddle-point solution. To that end, this work proposes a novel interception method that utilizes the swarm’s onboard PID controllers for setting the drones’ states during interception. The drone’s states are constrained only by their physical limitations, and only partial feedback of the adversarial drone’s positions is assumed. The new framework is evaluated in a virtual environment under different environmental and model settings, using random simulations of more than 165,000 swarm flights. For certain environmental settings, our results indicate that the interception performance of larger swarms under partial observation is comparable to that of a one-drone swarm under full observation of the adversarial drone.

How Do Inflammatory Mediators, Immune Response and Air Pollution Contribute to COVID-19 Disease Severity? A Lesson to Learn

Inflammatory and immune processes are defensive mechanisms that aim to remove harmful agents. As a response to infections, inflammation and immune response contribute to the pathophysiological mechanisms of diseases. Coronavirus disease 2019 (COVID-19), whose underlying mechanisms remain not fully elucidated, has posed new challenges for the knowledge of pathophysiology. Chiefly, the inflammatory process and immune response appear to be unique features of COVID-19 that result in developing a hyper-inflammatory syndrome, and air pollution, the world’s largest health risk factor, may partly explain the behaviour and fate of COVID-19. Understanding the mechanisms involved in the progression of COVID-19 is of fundamental importance in order to avoid the late stage of the disease, associated with a poor prognosis. Here, the role of the inflammatory and immune mediators in COVID-19 pathophysiology is discussed.

The sociocognitive processes of ideological obsession: review and policy implications

Understanding what motivates people to join violent ideological groups and engage in acts of cruelty against others is of great social and societal importance. In this paper, I posit that one necessary element is ‘ideological obsession’—an ideological commitment fuelled by unmet psychological needs and regulated by inhibitory and ego-defensive mechanisms. Drawing from evidence collected across cultures and ideologies, I describe four processes through which ideological obsession puts individuals on a path towards violence. First, ideological obsession deactivates moral self-regulatory processes, allowing unethical behaviours to be carried out without self-recrimination. Second, ideologically obsessed individuals are easily threatened by information that criticises their ideology, which in turn leads to hatred and violent retaliation. Third, ideological obsession changes people's social interactions by making them gravitate towards like-minded individuals who support ideological violence. As these social networks become more interconnected, they amplify one's adherence to violent extremism. Finally, ideologically obsessed individuals are prone to psychological reactance, making them immune to communication strategies intended to dissuade them from using violence. In fact, messages espousing non-violence can have the opposite effect by reinforcing their violence-supporting ideology. I conclude by presenting evidence-based strategies to prevent radicalisation leading to violence for individuals in pre-criminal spaces. This article is part of the theme issue ‘The political brain: neurocognitive and computational mechanisms’.