4,348 research outputs found

    Quantum Cryptography with Orthogonal States?

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    This is a Comment on Phys Rev Lett 75 (1995) 1239, by Goldenberg and VaidmanComment: 3 pages, LaTeX, 1 figure on separate page Final version in Phys Rev Lett 77 (1996) 326

    Water bathing alters the speed-accuracy trade-off of escape flights in European starlings

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    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).

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    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

    Exploring Tokenization Techniques to Optimize Patch-Based Time-Series Transformers

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    Transformer architectures have revolutionized deep learning, impacting natural language processing and computer vision. Recently, PatchTST has advanced long-term time-series forecasting by embedding patches of time-steps to use as tokens for transformers. This study examines and seeks to enhance PatchTST\u27s embedding techniques. Using eight benchmark datasets, we explore explore novel token embedding techniques. To this end, we introduce several PatchTST variants, which alter the embedding methods of the original paper. These variants consist of the following architectural changes: using CNNs to embed inputs to tokens, embedding an aggregate measure like the mean, max, or sum of a patch, adding the exponential moving average (EMA) of prior tokens to any given token, and adding a residual between neighboring tokens. Our findings show that CNN-based patch embeddings outperform PatchTST’s linear layer strategy, andsimple aggregate measures, particularly embedding just the mean of a patch, provide comparable results to PatchTST for some datasets. These insights highlight the potential for optimizing time-series transformers through improved embedding strategies. Additionally, they point to PatchTST\u27s inefficiency at exploiting all information available in a patch during the token embedding process

    I See You, I Feel Me: Journaling for Confidence, Value, and Collective Efficacy Among Partner Teachers

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    This action research sought to determine whether implementing a journaling practice that combined observation with self-reflection would improve the collective efficacy of an educational team. The research took place over one month in the single, early childhood classroom of a private Montessori school in the Midwest. Four partner teachers participated in the study: owner, director, and assistants. The project began with team-building exercises emphasizing open communication. The intervention required participants to record daily observations of partner teachers with corresponding reactions into personal I See You, I Feel Me journals. Data was collected through weekly attitude assessments, pre- and post-intervention focus group sessions, and artifacts. Using the benchmarks of confidence in roles, feelings of value, and perceptions of effectiveness, findings suggested journaling improved collective efficacy. This success recommends journaling as a useful tool for nurturing partner teaching relationships and evaluating collective efficacy. Continued research could examine widespread applicability and long-term effects

    Division of labour and risk taking in the dinosaur ant, Dinoponera quadriceps

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    The success of social insects can be largely attributed to division of labour. In contrast to most social insects, many species with simple societies contain workers which are capable of sexual reproduction. Headed by one or a few reproductive individuals, subordinate workers form a dominance hierarchy, queuing to attain the reproductive role. In these species task allocation may be influenced by individual choice based on future reproductive prospects. Individuals with a better chance of inheriting the colony may be less likely to take risks and high-ranking workers that spend a greater amount of time in proximity to the brood may be able to increase the ability to police egg-laying by cheating subordinates. We investigated division of labour and risk taking in relation to dominance rank in the queenless ponerine ant, Dinoponera quadriceps, a species with relatively simple societies. Using behavioural observations, we show that high-ranking workers spend more time performing egg care, less time foraging and are less likely to defend the nest against attack. High-rankers also spent a greater amount of time guarding and inspecting eggs, behaviours which are likely to improve detection of egg laying by cheating subordinates. We also show that high-ranking workers spend a greater amount of time idle, which may help increase lifespan by reducing energy expenditure. Our results suggest that both risk-taking and egg-care behaviours are related to future reproductive prospects in D. quadriceps. This highlights a mechanism by which effective division of labour could have been achieved during the early stages of eusocial evolution

    Steroids for acute COPD - but for how long?

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    "Steroids for acute COPD--but for how long? Not only was a shorter course of glucocorticoid therapy as effective as a 14-day regimen, but there was no difference in the time to next exacerbation."Prescribe a 5-day regimen of glucocorticoid therapy for acute chronic obstructive pulmonary disease (COPD) exacerbations; the shorter course of treatment appears to be as effective as a 14-day regimen

    Relativistic Doppler effect in quantum communication

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    When an electromagnetic signal propagates in vacuo, a polarization detector cannot be rigorously perpendicular to the wave vector because of diffraction effects. The vacuum behaves as a noisy channel, even if the detectors are perfect. The ``noise'' can however be reduced and nearly cancelled by a relative motion of the observer toward the source. The standard definition of a reduced density matrix fails for photon polarization, because the transversality condition behaves like a superselection rule. We can however define an effective reduced density matrix which corresponds to a restricted class of positive operator-valued measures. There are no pure photon qubits, and no exactly orthogonal qubit states.Comment: 10 pages LaTe
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