defensive strategies
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2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Marco Schade ◽  
Sebastian Stumpf ◽  
Jürgen Kriwet ◽  
Christoph Kettler ◽  
Cathrin Pfaff

AbstractNodosauridae is a group of thyreophoran dinosaurs characterized by a collar of prominent osteoderms. In comparison to its sister group, the often club-tailed ankylosaurids, a different lifestyle of nodosaurids could be assumed based on their neuroanatomy and weaponry, e.g., regarding applied defensive strategies. The holotype of the nodosaurid Struthiosaurus austriacus consists of a single partial braincase from the Late Cretaceous of Austria. Since neuroanatomy is considered to be associated with ecological tendencies, we created digital models of the braincase based on micro-CT data. The cranial endocast of S. austriacus generally resembles those of its relatives. A network of vascular canals surrounding the brain cavity further supports special thermoregulatory adaptations within Ankylosauria. The horizontal orientation of the lateral semicircular canal independently confirms previous appraisals of head posture for S. austriacus and, hence, strengthens the usage of the LSC as proxy for habitual head posture in fossil tetrapods. The short anterior and angular lateral semicircular canals, combined with the relatively shortest dinosaurian cochlear duct known so far and the lack of a floccular recess suggest a rather inert lifestyle without the necessity of sophisticated senses for equilibrium and hearing in S. austriacus. These observations agree with an animal that adapted to a comparatively inactive lifestyle with limited social interactions.


2022 ◽  
Vol 76 (1) ◽  
Author(s):  
Ignacio Escalante ◽  
Damian O. Elias

Abstract Defensive strategies, like other life-history traits favored by natural selection, may pose constraints on reproduction. A common anti-predator defense strategy that increases immediate survival is autotomy—the voluntary release of body parts. This type of morphological damage is considered to impose future costs for reproduction and fitness. We tested an alternative hypothesis that animals are robust (able to withstand and overcome perturbations) to this type of damage and do not experience any fitness costs in reproductive contexts. We explored the effects of experimental leg loss on the reproductive behavior of one species of Neotropical Prionostemma harvestmen. These arachnids undergo autotomy frequently, do not regenerate legs, and their courtship and mating necessitate the use of legs. We assessed the effect of losing different types of legs (locomotor or sensory) on courtship behavior and mating success in males. We found no differences in the mating success or in any measured aspect of reproductive behavior between eight-legged males and males that experienced loss of legs of any type. Additionally, we found that morphological traits related to body size did not predict mating success. Overall, our experimental findings support the null hypothesis that harvestmen are robust to the consequences of morphological damage and natural selection favors strategies that increase robustness. Significance statement In order to survive encounters with predators, animals have evolved many defensive strategies. Some of those behaviors, however, can come with a cost to their overall body condition. For example, some animals can voluntarily lose body parts (tails, legs, etc.) to escape. This process can then affect many aspects of an animal’s life, including reproduction. In a group of harvestmen (daddy long-legs) from Costa Rica, we tested the hypothesis that males are robust to the potential consequences of losing legs, and will not experience costs. We found that males that lost either legs used for locomotion or for sensory perception reproduced in the same way as animals with all of their legs. Consequently, we demonstrate that these arachnids are able to withstand the loss of legs with no effects on reproduction.


2022 ◽  
Vol 75 (suppl 3) ◽  
Author(s):  
Grizielle Sandrine de Araujo Rocha ◽  
Darine Marie Rodrigues da Silva ◽  
Maria Sandra Andrade ◽  
Bárbara Bruna Fernandes de Andrade ◽  
Sílvia Elizabeth Gomes de Medeiros ◽  
...  

ABSTRACT Objective: To analyze the suffering and coping strategies of nurses working in Primary Health Care considering the psychodynamics of their work. Methods: Descriptive study with a qualitative approach, carried out with 11 nurses working in Primary Health Care. Data were collected through semi-structured interviews, systematized, and interpreted using Bardin’s content analysis method applied to recurrent themes. Results: The suffering factors related to work in Primary Health Care are difficulties with management, the fragile structure of the health support network, and conflicts with the users. Defensive strategies to minimize these difficulties are the support of hierarchical superiors, the empowerment of the community and users, and communication between team members. Final considerations: It is important that there be changes in the organization of this line of work to improve the workers’ health.


Animals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 79
Author(s):  
Giuseppe De Marco ◽  
Fátima Brandão ◽  
Patrícia Pereira ◽  
Mário Pacheco ◽  
Tiziana Cappello

Metabolomics is a powerful approach in evaluating the health status of organisms in ecotoxicological studies. However, metabolomics data reflect metabolic variations that are attributable to factors intrinsic to the environment and organism, and it is thus crucial to accurately evaluate the metabolome of the tissue/organ examined when it is exposed to no stressor. The metabolomes of the liver and gills of wild golden grey mullet (Chelon auratus) from a reference area were analyzed and compared by proton nuclear magnetic resonance (1H NMR)-based metabolomics. Both organs were characterized by amino acids, carbohydrates, osmolytes, nucleosides and their derivatives, and miscellaneous metabolites. However, similarities and differences were revealed in their metabolite profile and related to organ-specific functions. Taurine was predominant in both organs due to its involvement in osmoregulation in gills, and detoxification and antioxidant protective processes in liver. Environmental exposure to mercury (Hg) triggered multiple and often differential metabolic alterations in fish organs. Disturbances in ion-osmoregulatory processes were highlighted in the gills, whereas differential impairments between fish organs were pointed out in energy-producing metabolic pathways, protein catabolism, membrane stabilization processes, and antioxidant defense system, reflecting the induction of organ-specific adaptive and defensive strategies. Overall, a strict correlation between metabolites and organ-specific functions of fish gills and liver were discerned in this study, as well as organ-specific cytotoxicity mechanisms of Hg in fish.


2021 ◽  
Author(s):  
Uriah Daugaard ◽  
Reinhard Furrer ◽  
Owen L. Petchey

Non-consumptive effects (NCEs) of predators on prey, such as induced defensive strategies, are frequently neglected in the analysis of predator-prey interactions. Yet these effects can have demographic impacts as strong as consumption. As a counterpart to NCEs, resource-availability effects (RAEs) can prompt changes in predators as well, e.g., in their foraging behavior. We studied NCEs and RAEs in the ciliate predator-prey pair Didinium nasutum and Paramecium caudatum. We examined the dependence of prey/predator swimming speed and body size on predator/prey presence. We also investigated prey spatial grouping behavior and the dependence of predator movement on local prey abundance. We collected individual movement and morphology data through videography of laboratory-based populations. We compared swimming speeds and body sizes based on their distributions. We used linear models to respectively quantify the effects of local prey abundance on predator displacements and of predator presence on prey grouping behavior. In the presence of prey, predator individuals swam more slowly, were bigger and made smaller displacements. Further, their displacements decreased with increasing local prey abundance. In contrast, in the presence of predators, proportionally more prey individuals showed a fast-swimming behavior and there was weak evidence for increased prey grouping. Trait changes entail energy expenditure shifts, which likely affect interspecific interactions and populations, as has been shown for NCEs. Less is known about the link between RAEs and demography, but it seems likely that the observed effects scale up to influence community and ecosystem stability, yet this remains largely unexplored.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sophie Füchtner ◽  
Sara Piqueras ◽  
Lisbeth Garbrecht Thygesen

AbstractTo decarbonize the building sector, the use of durable wood materials must be increased. Inspiration for environmentally benign wood protection systems is sought in durable tree species depositing phenolic extractives in their heartwood. Based on the hypothesis that the micro-distribution of extractives influences durability, we compared the natural impregnation patterns of non-durable, but readily available Norway spruce to more durable Kurile larch by mapping the distribution of heartwood extractives with Confocal Raman Imaging and multivariate data decomposition. Phenolics of both species were associated with hydrophobic oleoresin, likely facilitating diffusion through the tissue. They accumulated preferentially in lignin-rich sub-compartments of the cell wall. Yet, the distribution of extractives was found not to be the same. The middle lamellae contained flavonoids in larch and aromatic waxes in spruce, which was also found in rays and epithelial cells. Spruce-lignans were tentatively identified in all cell types, while larch-flavonoids were not present in resin channels, hinting at a different origin of synthesis. Larch-oleoresin without flavonoids was only found in lumina, indicating that the presence of phenolics in the mixture influences the final destination. Together our findings suggest, that spruce heartwood-defense focuses on water regulation, while the more efficient larch strategy is based on antioxidants.


2021 ◽  
Vol 12 ◽  
Author(s):  
Rachele Mariani ◽  
Alessandro Gennaro ◽  
Silvia Monaco ◽  
Michela Di Trani ◽  
Sergio Salvatore

The Coronavirus-19 (COVID-19) pandemic posed a significant challenge to the physical, mental, and emotional well-being of each individual. It also brought the importance of daily emotional management for survival to the forefront of every human being. Our study aims to explore whether emotional processes perform different functions during waking thoughts and night dreams during the first lockdown in Italy. Utilizing Multiple Code Theory (MCT), our goal is to verify whether waking thoughts facilitate a functional disconnection in order to manage the trauma caused by COVID-19. Two online forms were distributed to random participants in the general population, presenting a total of 49 reports of night dreams (23 males; mean age 33.45 ds. 10.12; word mean 238.54 ds. 146.8) and 48 reports of waking thoughts (25 males; mean age 34.54 ds. 12.8; word mean M. 91 words ds. 23). The Referential Process linguistic measures and Affect Salience Index were utilized. It was found that Affect Salience is present in both dreams and in waking thoughts; however, Referential Activity was higher in dreams and Reflection and Affect words were higher in waking thoughts. Two different processes of emotional elaboration emerged. The results highlight the use of greater symbolization processes during dreams and a higher emotional distance in waking thoughts. These results confirm that during the nocturnal processes, there is greater contact with the processing of trauma, while during the diurnal processes, defensive strategies were activated to cope with and manage life via a moment of the defensive disruption of daily activities.


2021 ◽  
Vol 12 ◽  
Author(s):  
Fan Mao ◽  
Kunna Liu ◽  
Nai-Kei Wong ◽  
Xiangyu Zhang ◽  
Wenjie Yi ◽  
...  

Vibrio species are ubiquitously distributed in marine environments, with important implications for emerging infectious diseases. However, relatively little is known about defensive strategies deployed by hosts against Vibrio pathogens of distinct virulence traits. Being an ecologically relevant host, the oyster Crassostrea hongkongensis can serve as an excellent model for elucidating mechanisms underlying host-Vibrio interactions. We generated a Vibrio alginolyticus mutant strain (V. alginolyticus△vscC) with attenuated virulence by knocking out the vscC encoding gene, a core component of type III secretion system (T3SS), which led to starkly reduced apoptotic rates in hemocyte hosts compared to the V. alginolyticusWT control. In comparative proteomics, it was revealed that distinct immune responses arose upon encounter with V. alginolyticus strains of different virulence. Quite strikingly, the peroxisomal and apoptotic pathways are activated by V. alginolyticusWT infection, whereas phagocytosis and cell adhesion were enhanced in V. alginolyticus△vscC infection. Results for functional studies further show that V. alginolyticusWT strain stimulated respiratory bursts to produce excess superoxide (O2•−) and hydrogen peroxide (H2O2) in oysters, which induced apoptosis regulated by p53 target protein (p53tp). Simultaneously, a drop in sGC content balanced off cGMP accumulation in hemocytes and repressed the occurrence of apoptosis to a certain extent during V. alginolyticus△vscC infection. We have thus provided the first direct evidence for a mechanistic link between virulence of Vibrio spp. and its immunomodulation effects on apoptosis in the oyster. Collectively, we conclude that adaptive responses in host defenses are partially determined by pathogen virulence, in order to safeguard efficiency and timeliness in bacterial clearance.


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