3,701 research outputs found
Water bathing alters the speed-accuracy trade-off of escape flights in European starlings
Birds of most species regularly bathe in water, but the function of this behaviour is unknown. We tested the hypothesis that water bathing is important in feather maintenance, and hence should enhance flight performance. We manipulated European starlings', Sturnus vulgaris, access to bathing water in a 2 × 2 design: birds were housed in aviaries either with or without water baths for a minimum of 3 days (long-term access) before being caught and placed in individual cages either with or without water baths for a further 24 h (short-term access). We subsequently assessed the speed and accuracy of escape flights through an obstacle course of vertical strings. Birds that had bathed in the short-term flew more slowly and hit fewer strings than birds that were deprived of bathing water in the short term, whereas long-term access to bathing water had no significant effect on flight performance. Thus recent access to bathing water alters flight performance by altering the trade-off between escape flight speed and accuracy. We hypothesize that lack of bathing water provision could increase anxiety in captive starlings because of an increase in their perceived vulnerability to predation. This study therefore potentially provides an important functional link between the expression of natural behaviours in captivity and welfare considerations. © 2009 The Association for the Study of Animal Behaviour
Quantification of abnormal repetitive behaviour in captive European starlings (Sturnus vulgaris).
Stereotypies are repetitive, unvarying and goalless behaviour patterns that are often considered indicative of poor welfare in captive animals. Quantifying stereotypies can be difficult, particularly during the early stages of their development when behaviour is still flexible. We compared two methods for objectively quantifying the development of route-tracing stereotypies in caged starlings. We used Markov chains and T-pattern analysis (implemented by the software package, Theme) to identify patterns in the sequence of locations a bird occupied within its cage. Pattern metrics produced by both methods correlated with the frequency of established measures of stereotypic behaviour and abnormal behaviour patterns counted from video recordings, suggesting that both methods could be useful for identifying stereotypic individuals and quantifying stereotypic behaviour. We discuss the relative benefits and disadvantages of the two approaches
El Bloqueo and the Initial Changes to Expect in Cuba Following its Repeal
This document seeks the answer to the question, What will happen when the Embargo in place against Cuba by the U. S. government is lifted? This question undoubtedly came to the front of many Americans’ minds when President Obama announced on December 17,2014 that the United States and Cuba would begin diplomatic relations by opening embassies in the capital city of one another\u27s state. It uses various sources to define the Cuban Embargo and the events that led to its manifestation, the current state of affairs with Cuba (roughly 2 years after the announcement). While the United States seeks a more democratic form of government for the Cuban people, it may come over a longer period of time. This document looks for the most important immediate impact of the removal of the embargo
Optimal distinction between non-orthogonal quantum states
Given a finite set of linearly independent quantum states, an observer who
examines a single quantum system may sometimes identify its state with
certainty. However, unless these quantum states are orthogonal, there is a
finite probability of failure. A complete solution is given to the problem of
optimal distinction of three states, having arbitrary prior probabilities and
arbitrary detection values. A generalization to more than three states is
outlined.Comment: 9 pages LaTeX, one PostScript figure on separate pag
Communications Biophysics
Contains reports on two research projects.National Institutes of Health (Grant 5 P01 GM14940-05
Convex probability domain of generalized quantum measurements
Generalized quantum measurements with N distinct outcomes are used for
determining the density matrix, of order d, of an ensemble of quantum systems.
The resulting probabilities are represented by a point in an N-dimensional
space. It is shown that this point lies in a convex domain having at most d^2-1
dimensions.Comment: 7 pages LaTeX, one PostScript figure on separate pag
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