Ontogenetic development of magnetic compass orientation in domestic chickens (Gallus gallus)

Domestic chickens (Gallus gallus) can be trained to search for a social stimulus in a specific magnetic direction, and cryptochrome 1a, found in the retina, has been proposed as a receptor molecule mediating magnetic directions. The present study combines immuno-histochemical and behavioural data to analyse the ontogenetic development of this ability. Newly hatched chicks already have a small amount of cryptochrome 1a in their violet cones; on day 5, the amount of cryptochrome 1a reached the same level as in adult chickens, suggesting that the physical basis for magnetoreception is present. In behavioural tests, however, young chicks 5 to 7. days old failed to show a preference of the training direction; on days 8, 9 and 12, they could be successfully trained to search along a specific magnetic axis. Trained and tested again 1. week later, the chicks that had not shown a directional preference on days 5 to 7 continued to search randomly, while the chicks tested from day 8 onward preferred the correct magnetic axis when tested 1. week later. The observation that the magnetic compass is not functional before day 8 suggests that certain maturation processes in the magnetosensitive system in the brain are not yet complete before that day. The reasons why chicks that have been trained before that day fail to learn the task later remain unclear

Imprinting.

Imprinting is a type of learning by which an animal restricts its social preferences to an object after exposure to that object. Filial imprinting occurs shortly after birth or hatching and sexual imprinting, around the onset of sexual maturity; both have sensitive periods. This review is concerned mainly with filial imprinting. Filial imprinting in the domestic chick is an effective experimental system for investigating mechanisms underlying learning and memory. Extensive evidence implicates a restricted part of the chick forebrain, the intermediate and medial mesopallium (IMM), as a memory store for visual imprinting. After imprinting to a visual stimulus, neuronal responsiveness in IMM is specifically biased toward the imprinting stimulus. Both this bias and the strength of imprinting measured behaviorally depend on uninterrupted sleep shortly after training. When learning-related changes in IMM are lateralized they occur predominantly or completely on the left side. Ablation experiments indicate that the left IMM is responsible for long-term storage of information about the imprinting stimulus; the right side is also a store but additionally is necessary for extra storage outside IMM, in a region necessary for flexible use of information acquired through imprinting. Auditory imprinting gives rise to biochemical, neuroanatomical, and electrophysiological changes in the medio-rostral nidopallium/mesopallium, anterior to IMM. Auditory imprinting has not been shown to produce learning-related changes in IMM. Imprinting may be facilitated by predispositions. Similar predispositions for faces and biological motion occur in domestic chicks and human infants. WIREs Cogn Sci 2013, 4:375-390. doi: 10.1002/wcs.1231 For further resources related to this article, please visit the WIREs website.This review is written in memory of the late Sir Gabriel Horn, in recognition of his pioneering work on the neurobiology of imprinting. I am indebted to Robert Levin, Alister Nicol, Revaz Solomonia, Rie Suge, and two anonymous referees for valuable comments on a draft manuscript. The review was written while in receipt of a project grant from the Biotechnology and Biological Sciences Research Council.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1002/wcs.123

Effects of environmental novelty on filial behavior in imprinted ducklings

Environmental novelty was manipulated in imprinted ducklings by varying the illumination level of the experimental apparatus. Bright illumination disrupted filial behavior in subjects that had received little prior exposure to the imprinting object, with approach being suppressed more when the object was stationary than when it was moving. In subjects with prolonged prior imprinting exposure, bright illumination enhanced filial behavior. These effects can be understood if one assumes that environmental novelty has an energization effect while also eliciting responses that are incompatible with filial behavior. © 1983 Psychonomic Society, Inc

Communal roosting in birds.

Selection of roosting site is often influenced by species-typical preferences for particular habitats, by proximity to food and water and by isolation from human activity. Birds usually show strong loyalty to a given site. Some species approach roosts in stages that include assembly at feeding grounds, gathering along established flight-lines, assembly in the immediate vicinity of the roost and finally entry into the roost itself. Roost departures typically have fewer assembly rituals during the return to feeding grounds; more birds leave simultaneously and at lower light intensities. The most important factor governing roosting flights is probably illumination level, but other factors (eg temperature, wind, hunger, social stimuli, distance of destination, time of day and time of year) also play roles. On a daily as well as seasonal basis, roost populations fluctuate greatly in total numbers and in age and sex composition. Mixed species roosts are not uncommon, and have implications for survival value. Potential survival values of communal roosting include thermoregulation, protection from predation, increased feeding efficiency, population regulation and preparation for migration. -Autho

Contextual generality of roosttime restlessness in captive American robins (Turdus migratorius)

A series of experiments with captive American robins examined factors affecting roosttime restlessness, that is, the burst of locomotor activity that appears at dusk and is thought to be a correlate of the communal roosting habit of this species. First, the restlessness occurred earlier on cloudy days than on sunny ones, suggesting the importance of illumination level in initiating the activity burst. Second, in studies on social effects, the restlessness was greater when robins were totally isolated than when they had visual-auditory access to conspecifics; indeed, when a small flock of robins was housed together, restlessness at dusk was suppressed completely. Third, the birds were more restless when they could see a human observer than when they could not, implying an interaction of tearfulness with the roosting tendency. Finally, restlessness occurred in a large flight cage as well as in small cages, as long as the birds were not maintained in a flock. In sum, roosttime restlessness appears to be a robust phenomenon that occurs under a wide range of laboratory conditions, but which also can be substantially influenced by numerous environmental variables. Further experimental examination of these variables may advance present understanding of the survival value of communal roosting in this species. © 1981 Psychonomic Society, Inc

Persistence of acquired behavioral control in the context of imprinting

Newly hatched Khaki Campbell ducklings (Anas platyrhynchos domesticus) were exposed to a moving object that immediately suppressed distress vocalizations occurring in a novel environment. The static visual and auditory features of this object acquired the ability to suppress distress vocalizations after eight 20-min sessions of exposure to the object in motion. The acquired suppressive properties of these features were found to persist throughout thirty 20-min sessions given over 10 days. During these sessions, the ducklings were continually exposed to the static features in the absence of visual movement. In a second experiment, the ability of these features in the absence of visual movement. In a second experiment, the ability of these features to serve as reinforcement for a pecking response was shown to persist for up to 56 hr. In one duckling, presentations of the static visual features did not maintain pecking behavior. However, it was shown that pecking responses could be re-instated in this duckling by introducing novel stimuli to the environment

Effects of environmental novelty on distress vocalizations of ducklings following withdrawal of an imprinting object

Imprinted ducklings typically pause several seconds before initiating distress vocalizations following withdrawal of an imprinting object. In the present research, this pause was found to be shorter in the presence of a novel, presumably fear-inducing stimulus. This in turn implies that environmental novelty added to withdrawal of the imprinting object in determining the affective state of the ducklings. Although opponent process theory has no trouble with such additive effects, the very occurrence of the poststimulus pause presents problems for the theory. © 1990, The Psychonomic Society, Inc.. All rights reserved

Adhesion improvement of electroless copper depositions on titanium nitride by low temperature annealing

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references (leaves 56-57).Issued also on microfiche from Lange Micrographics.Due to the ever decreasing dimensions of the inter-level metallic interconnects, alternative metal deposition processes must be explored as the current processes (chemical vapor deposition (CVD) and physical vapor deposition (PVDI) are reaching their limits on coverage and uniformity. One such alternative is electronics copper which may be used either to produce a conductive seed layer for electroplating fill or used solely as a fill process. This work attempts to further the knowledge of electronics copper depositions onto titanium nitride, a diffusion barrier material. In particular, an effort is made to characterize the adhesion of the electronics copper deposit on titanium nitride and the improvement of the adhesion produced by low temperature, short duration annealing. The duration of the annealing is varied from 5 to 300 seconds, the temperature varied from 60 to 300C̊, and the thickness of the copper varied from 275 to 400 angstroms. Additionally, work is presented which tries to determine the actual physical mechanism responsible for the improved adhesion after annealing