Search results for "mechanism"
showing 5 items of 1835 documents
Multiple modalities in insect warning displays have additive effects against wild avian predators
2019
Allocation to different components of defence has been suggested as an explanation for the existence of multiple aposematic morphs in a single population. We tested whether there are trade-offs between warning colouration and chemical defence or whether these have an additive effect when combined, using blue tits (Cyanistes caeruleus) as predators and the polymorphic wood tiger moth (Arctia plantaginis) as prey. We used artificial edible models (with and without the moths’ defensive fluids) with paper wings whose colour and pattern properties matched those of real moths. When the models were presented sans defensive fluids or when the fluids were presented without colour cues, we detected n…
Influence of colour, smell and taste on the survival of the wood tiger moth (Arctia plantaginis) adults during predation event
2021
Saalistajien torjumiseksi saalis voi käyttää erilaisia puolustusmekanismeja, jotka stimuloivat useita eri aisteja (ts. multimodaalista signalointia). Esimerkiksi aposemaattiset eliöt puolustautuvat varoitussignaalin lisäksi sekundaarisella puolustuksella. Tässä tutkimuksessa keskityttiin siihen, kuinka täpläsiilikkään (Arctia plantaginis) väritys (genotyypit WW, Wy ovat valkoisia ja yy keltaisia), haju (metoksipyratsiinista) ja maku (pyrrolitsidiinialkaloidista) toimivat puolustuksena lintusaalistajien hyökkäyksiä vastaan. Linnuille tarjottiin kummankin värisiä eläviä siilikkäitä, joita oli manipuloitu niin, että niillä oli joko hajua, makua tai molempia näistä. Näin pystyttiin tutkimaan ku…
Lagrangian matches between observations from aircraft, lidar and radar in a warm conveyor belt crossing orography
2021
Warm conveyor belts (WCBs) are important airstreams in extratropical cyclones, often leading to the formation of intense precipitation and the amplification of upper-level ridges. This study presents a case study that involves aircraft, lidar and radar observations in a WCB ascending from western Europe towards the Baltic Sea during the Hydrological Cycle in the Mediterranean Experiment (HyMeX) and T-NAWDEX-Falcon in October 2012, a preparatory campaign for the THORPEX North Atlantic Waveguide and Downstream Impact Experiment (TNAWDEX). Trajectories were used to link different observations along the WCB, that is, to establish so-called Lagrangian matches between observations. To this aim, a…
The Influence Mechanism of Supervisor Developmental Feedback on the Enactment of Employees’ Creative Ideas: A Moderated Chain Mediation Model Based o…
2021
Employees’ creative idea enactment is critical for organizational creativity assessment and innovation implementation. In the paper, we want to develop and verify a moderated chain mediation model to explore the impact of supervisor developmental feedback on the enactment of employees’ creative ideas, and to investigate the moderating role of psychological empowerment further. Hierarchical regression analyses of the multi-time data from 375 employees in China indicate that positive emotions and work engagement, respectively mediate the relationship between supervisor developmental feedback and employees’ creative idea enactment. Simultaneously, positive emotions and work engagement form cha…
Piston driven yaw mechanism
2014
Masteroppgave i mekatronikk MAS 500 Universitetet i Agder 2014 The current thesis presents a piston driven yaw mechanism for wind turbines. Traditionally the yaw mechanismhas been one of the mayor contributors to down time and repair has been costly. The proposed designaims to improve the reliability of the yaw mechanism by reducing the point loads and by using hydrauliccylinders instead electrical motors to generate torque. In addition the design is modular allowing the mechanismto be disassembled and components to be replaced without the requirement of complicated or costlymachinery. The current thesis presents an analysis of the state of the art and discusses concepts which maysolve some…