Search results for " Avoidance"
showing 10 items of 172 documents
Meritevolezza degli interessi
2021
La voce affronta l’evoluzione del criterio della meritevolezza degli interessi, indagandone la genesi e poi analizzandone le principali concezioni. Da questo esame emerge che la meritevolezza fonda un giudizio di impronta causale sul contratto, principalmente atipico ma anche, sotto certi aspetti, su quello tipico, che va distinto da quello di liceità. La meritevolezza dà infatti forma a una delle due anime del sindacato sulla causa del contratto: quello teso a riscontrare il fondamento del contratto sul terreno economico e sociale tramite una valutazione di natura tipologica sulla razionalità dello schema di composizione degli interessi e sulla consistenza e diffusione di questi ultimi; e …
Vertebrate defense against parasites: Interactions between avoidance, resistance, and tolerance
2017
Hosts can utilize different types of defense against the effects of parasitism, including avoidance, resistance, and tolerance. Typically, there is tremendous heterogeneity among hosts in these defense mechanisms that may be rooted in the costs associated with defense and lead to trade‐offs with other life‐history traits. Trade‐offs may also exist between the defense mechanisms, but the relationships between avoidance, resistance, and tolerance have rarely been studied. Here, we assessed these three defense traits under common garden conditions in a natural host–parasite system, the trematode eye‐fluke Diplostomum pseudospathaceum and its second intermediate fish host. We looked at host ind…
Implications of size‐selective fisheries on sexual selection
2019
Fisheries often combine high mortality with intensive size‐selectivity and can, thus, be expected to reduce body size and size variability in exploited populations. In many fish species, body size is a sexually selected trait and plays an important role in mate choice and mate competition. Large individuals are often preferred as mates due to the high fecundity and resources they can provide to developing offspring. Large fish are also successful in competition for mates. Fisheries‐induced reductions in size and size variability can potentially disrupt mating systems and lower average reproductive success by decreasing opportunities for sexual selection. By reducing population sizes, fisher…
Experience and dominance in fish pairs jointly shape parasite avoidance behaviour
2018
There is increasing evidence that the composition of a social group influences the fitness of its members. For example, group member identities can determine the exposure risk to contact-transmitted parasites and consequently impact the health of all group members. Here, we propose that group composition may also affect host exposure to parasite propagules prevailing in the environment via collective parasite avoidance behaviours. We explored the spatial avoidance of a trematode parasite, Diplostomum pseudospathaceum, using the simplest form of host groups, pairs of sea trout, Salmo trutta trutta. These pairs showed either (1) between-group heterogeneity in their experience with the parasit…
Spontaneous quantity discrimination of artificial flowers by foraging honeybees
2020
ABSTRACTMany animals need to process numerical and quantity information in order to survive. Spontaneous quantity discrimination allows differentiation between two or more quantities without reinforcement or prior training on any numerical task. It is useful for assessing food resources, aggressive interactions, predator avoidance and prey choice. Honeybees have previously demonstrated landmark counting, quantity matching, use of numerical rules, quantity discrimination and arithmetic, but have not been tested for spontaneous quantity discrimination. In bees, spontaneous quantity discrimination could be useful when assessing the quantity of flowers available in a patch and thus maximizing f…
A manipulative parasite increasing an antipredator response decreases its vulnerability to a nonhost predator.
2009
8 pages; International audience; Trophically transmitted parasites have to deal with the antipredator adaptations of their intermediate hosts. Some of these parasites induce behavioural changes in their intermediate hosts that make them more vulnerable to predation by definitive hosts. However, the adaptiveness of behavioural manipulation also depends on the probability of being eaten by a nonhost predator. Parasites might therefore try to use specific antipredator responses of intermediate hosts to avoid this dead end. We tested this hypothesis using the acanthocephalan Polymorphus minutus and its intermediate amphipod host, Gammarus roeseli. In their natural habitat, uninfected G. roeseli…
Prolonged stigma and flower lifespan in females of the gynodioecious plant Geranium sylvaticum
2017
tIn gynodioecious plants females need a reproductive advantage over hermaphrodites to be maintainedin the same population. Generally, three main proximate causes for a female advantage are considered:inbreeding avoidance, different resource allocation patterns, and differences in ecological interactions.A mechanism potentially causing a female advantage that is rarely discussed is a difference in flo-ral longevity between the genders. Females may have a longer stigma lifespan than hermaphrodites,which can affect pollination. Stigma and flower lifespan are rarely documented in gynodioecious species,although it is a common observation in dioecious species that female plants flower longer than…
Smart sensing and adaptive reasoning for enabling industrial robots with interactive human-robot capabilities in dynamic environments — a case study
2019
Traditional industry is seeing an increasing demand for more autonomous and flexible manufacturing in unstructured settings, a shift away from the fixed, isolated workspaces where robots perform predefined actions repetitively. This work presents a case study in which a robotic manipulator, namely a KUKA KR90 R3100, is provided with smart sensing capabilities such as vision and adaptive reasoning for real-time collision avoidance and online path planning in dynamically-changing environments. A machine vision module based on low-cost cameras and color detection in the hue, saturation, value (HSV) space is developed to make the robot aware of its changing environment. Therefore, this vision a…
Real-time human collision detection for industrial robot cells
2017
A collision detection system triggering on human motion was developed using the Robot Operating System (ROS) and the Point Cloud Library (PCL). ROS was used as the core of the programs and for the communication with an industrial robot. Combining the depths fields from the 3D cameras was accomplished by the use of PCL. The library was also the underlying tool for segmenting the human from the registrated point clouds. Benchmarking of several collision algorithms was done in order to compare the solution. The registration process gave satisfactory results when testing the repetitiveness and the accuracy of the implementation. The segmentation algorithm was able to segment a person represente…
A novel clustering-based algorithm for solving spatially-constrained robotic task sequencing problems
2021
The robotic task sequencing problem (RTSP) appears in various forms across many industrial applications and consists of developing an optimal sequence of motions to visit a set of target points defined in a task space. Developing solutions to problems involving complex spatial constraints remains challenging due to the existence of multiple inverse kinematic solutions and the requirements for collision avoidance. So far existing studies have been limited to relaxed RTSPs involving a small number of target points and relatively uncluttered environments. When extending existing methods to problems involving greater spatial constraints and large sets of target points, they either require subst…