Search results for " defence"
showing 10 items of 415 documents
Redox Systems, Oxidative Stress, and Antioxidant Defences in Health and Disease
2021
Reactive oxygen and nitrogen species (RONS) play a key role in the regulation of cell survival. While adequate levels of RONS are essential to sustain cell proliferation and survival, disruption of the endocellular redox state induces cell dysfunction and death. Indeed, under physiological conditions, a balance between the generation and elimination of RONS ensures the proper function of redox-sensitive signalling proteins. Conversely, alterations to the redox homeostasis may disrupt the function of key transcription factors, signaltransduction pathways and cell-death regulators. Along these lines, understanding the mechanisms underlying cellular redox homeostasis may help to develop nutrac…
Social information use by predators : expanding the information ecology of prey defences
2022
Social information use is well documented across the animal kingdom, but how it influences ecological and evolutionary processes is only just beginning to be investigated. Here we evaluate how social transmission may influence species interactions and potentially change or create novel selection pressures by focusing on predator-prey interactions, one of the best studied examples of species coevolution. There is extensive research into how prey can use social information to avoid predators, but little synthesis of how social transmission among predators can influence the outcome of different stages of predation. Here we review evidence that predators use social information during 1) encount…
The effects of populism as a social identity frame on persuasion and mobilization: evidence from a 15-country experiment
2020
This article investigates the impact of populist messages on issue agreement and readiness for action in 15 countries (N = 7,286). Specifically, populist communicators rely on persuasive strategies by which social group cues become more salient and affect people's judgment of and political engagement with political issues. This strategy is called ‘populist identity framing’ because the ordinary people as the in‐group is portrayed as being threatened by various out‐groups. By blaming political elites for societal or economic problems harming ordinary people, populist communicators engage in anti‐elitist identity framing. Another strategy is to blame immigrants for social problems – that is, …
Nonlinear rocking of rigid blocks on flexible foundation: Analysis and experiments
2017
Abstract Primarily, two models are commonly used to describe rocking of rigid bodies; the Housner model, and the Winkler foundation model. The first deals with the motion of a rigid block rocking about its base corners on a rigid foundation. The second deals with the motion of a rigid block rocking and bouncing on a flexible foundation of distributed linear springs and dashpots (Winkler foundation). These models are two-dimensional and can capture some of the features of the physics of the problem. Clearly, there are additional aspects of the problem which may be captured by an enhanced nonlinear model for the base-foundation interaction. In this regard, what it is adopted in this paper is …
Experimental inhibition of nitric oxide increases Plasmodium relictum (lineage SGS1) parasitaemia.
2012
7 pages; International audience; Malaria is a widespread vector-borne disease infecting a wide range of terrestrial vertebrates including reptiles, birds and mammals. In addition to being one of the most deadly infectious diseases for humans, malaria is a threat to wildlife. The host immune system represents the main defence against malaria parasites. Identifying the immune effectors involved in malaria resistance has therefore become a major focus of research. However, this has mostly involved humans and animal models (rodents) and how the immune system regulates malaria progression in non-model organisms has been largely ignored. The aim of the present study was to investigate the role of…
The Impact of Copper Ions on Oxidative Stress in Garden Cress Lepidium sativum
2017
Abstract Normal oxygen metabolism is an endogenous source of reactive oxygen species (ROS). The source of ROS are also many environmental factors including heavy metals. In certain concentration range, the presence of ROS is necessary to maintain proper cell function. Thus, cells have many mechanisms, which role is focused on maintaining a constant concentration of ROS. Imbalance between the formation of ROS and action of a protective antioxidant system leads to oxidative stress. This may results with a damage to the structure of proteins, lipids and nucleic acids, which in turn can lead to disturbances in the functioning of the cell and even to the death. The aim of the study was to evalua…
Profiles and Sources of PAHs in Sediments from an Open-Pit Mining Area in the Peruvian Andes
2015
The Peruvian Andes are one of the most productive areas for mining and therefore also one of the most exposed to these sources of pollution. This article reports the characterization of Polycyclic Aromatic Hydrocarbons (PAHs) in sediments of Cerro de Pasco area (Peru) located close to a large open-pit mine and, in recent years, several reports have provided evidence of environmental contamination and related health problems. Investigations were carried out into the fifteen PAHs identified by the US-Environment Protection Agency (US-EPA) as requiring priority monitoring, other non US-EPA listed PAHs and perylene were also investigated in order to obtain further information on their origins. …
Brief communication: Vehicle routing problem and UAV application in the post-earthquake scenario
2017
Abstract. In this paper we simulate a Unmanned Aerial Vehicle's (UAV) recognition after a possible case of diffuse damage after a seismic event in the town of Acireale (Sicily, Italy). Given a set of sites (84 relevant buildings) and the range of the UAV, we are able to find the number of vehicles to employ and the shortest survey path. The problem of finding the shortest survey path is an operational research problem called Vehicle Routing Problem (VRP) whose solution is known to be computationally time-consuming. We used the Simulated Annealing (SA) heuristic that is able to provide stable solutions in relatively short computing time. We also examined the distribution of the cost of the s…
The Power of Literature to Decipher the Archetype of Lone-Wolf
2021
The Soviet Union collapse marked the end of the Cold War and the rise of the US as the only superpower, at least until 9/11, a foundational event where four civil aeroplanes were directed against the commercial and military hallmarks of the most powerful nation. Terrorism and the so-called War on Terror characterized the turn of a bloody century whose legacy remains to date. The chapter explores the dilemmas of lone-wolf terrorism from the lens of literature as well as cultural theory. The authors hold the thesis that terrorism activates some long-dormant narrative forged in the colonial period respecting to the “non-Western other.” Having said this, the chapter dissects the plot of some no…