Does Environmental Enrichment Reduce Stress? An Integrated Measure of Corticosterone from Feathers Provides a Novel Perspective

Enrichment is widely used as tool for managing fearfulness, undesirable behaviors, and stress in captive animals, and for studying exploration and personality. Inconsistencies in previous studies of physiological and behavioral responses to enrichment led us to hypothesize that enrichment and its removal are stressful environmental changes to which the hormone corticosterone and fearfulness, activity, and exploration behaviors ought to be sensitive. We conducted two experiments with a captive population of wild-caught Clark's nutcrackers (Nucifraga columbiana) to assess responses to short- (10-d) and long-term (3-mo) enrichment, their removal, and the influence of novelty, within the same animal. Variation in an integrated measure of corticosterone from feathers, combined with video recordings of behaviors, suggests that how individuals perceive enrichment and its removal depends on the duration of exposure. Short- and long-term enrichment elicited different physiological responses, with the former acting as a stressor and birds exhibiting acclimation to the latter. Non-novel enrichment evoked the strongest corticosterone responses of all the treatments, suggesting that the second exposure to the same objects acted as a physiological cue, and that acclimation was overridden by negative past experience. Birds showed weak behavioral responses that were not related to corticosterone. By demonstrating that an integrated measure of glucocorticoid physiology varies significantly with changes to enrichment in the absence of agonistic interactions, our study sheds light on potential mechanisms driving physiological and behavioral responses to environmental change

Face2Face, una actividad para la orientación profesional

Congreso Universitario de Innovación Educativa En las Enseñanzas Técnicas, CUIEET (26º. 2018. Gijón

Meandered Waveguides for Active Antennas

International audienceMeandered Waveguides are novel RF components which may play a disruptive role in phased array antennas. They permit to guarantee low propagation losses, comparable to the ones of conventional waveguides, combined with an increased freedom in defining their path, comparable with the one associated to flexible coaxial cables. In addition, meandered waveguides can provide a full control of the phase, which is fundamental to design Beam Forming Networks. Additive Manufacturing represents today the best technology to realize meandered waveguides with improvements in terms of cost, complexity, accommodation, and accuracy. In the paper in order to demonstrate the effectiveness of meandered waveguides possible exploitations in active arrays and discrete constrained lenses are proposed. © 2021 EurAAP

Mm-wave antennas and components: Profiting from 3D-printing

International audienceThe goal of this manuscript is to show the potential of additive manufacturing (AM) to produce cost-effective high-performance passive mm-wave components and antennas. We focus on the particular AM technique developed by SWISSto12 based on the so called Stereolithography (SLA), which consists on the 3D-printing of a skeleton of the component using a non-conductive polymer. Chemical copper plating is then applied in order to make all component surfaces RF-conductive. One of the most relevant advantages associated to this approach stems from its ability to produce low-weight monolithic devices. Two 3D-printed RF-devices operating at mm-waves are here presented: a Ka-band radiating element and a V-band orthomode-transducer. Both devices have been firstly designed using full-wave solvers, then manufactured and finally validated through measurements. © 2017 IEEE

Compact Orthomode Transducer with Broadband Beamforming Capability

A compact and broadband orthomode transducer (OMT) with two dual linearly polarized ports is reported here for the first time. The component is based on a combination of two ridged Boifot junctions through a series of power dividers that act as an embedded first level of the beamforming network. The design technique of the new OMT is discussed in the paper through an example that operates at Ku-band (10.7 GHz to 14.5 GHz) suitable for Satellite-on-the-Move (SOTM) user terminals. Measurement results of an additive manufactured (AM) monolithic prototype are presented, showing a good agreement with the simulation results