12,093 research outputs found

    Recognising & assessing positive welfare: developing positive indicators for use in welfare assessment

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    The use of positive welfare indicators: a proactive approach. Welfare assessment methods have developed greatly over recent decades with regards to both behavioural and physiological indicators. However, whether welfare is being assessed on the basis of biological function, affective state or ‘naturalness’, the emphases have remained heavily on identifying those key indicators of poor welfare or welfare concerns that require more immediate action, often via legislative change. The reactive approach in identifying welfare concerns has been the underpinning force behind legislative changes to mould animal management systems into more acceptable arrangements but as consumer interest in food sourcing grows, it is becoming increasingly apparent that acceptable is no longer enough and positive welfare indicators offer a future avenue for developing improved, ‘higher welfare’ systems in a more proactive manner [1]. The benefits of employing positive welfare indicators as assessment tools offer potential avenues of development for all animal sectors, not just within agriculture. Positive welfare indicators can fall into 3 categories: indications of contentment / pleasure, luxury behaviours, and behaviours that support ability to cope with challenge. Indications of contentment / pleasure. Good welfare is not just an absence of negative experiences but also an ability to experience positive affective states. The ability of non-human animals to experience emotions in the same manner as humans remains a controversial topic, however, recent advances in neuroscience have been used to evidence the existence of positive affective states in animals with regards to behaviours such as positive anticipation [2]. Luxury behaviours. Luxury behaviours are often deemed to be key positive welfare indicators due to them being the first behaviours to be lost during challenging situations. As such, any occurrences have been assigned the ‘good welfare’ indicator label – if the animal is performing these behaviours then the situation must be of a sufficient welfare level to enable them to. These luxury behaviours have often been considered separate from those ‘fundamental’ behavioural needs [3] so commonly used to determine minimum requirements in welfare legislation. There is, however, a risk that by focusing on the more urgent ‘demand’ behaviours, a situation may never be achieved that is high enough for the luxury behaviours to occur. As the luxury behaviours may be indicative of less transparent long-term rewards, their absence could still result in negative or less favourable consequences for the animal involved. The identification of key luxury behaviours for different species could therefore become essential tools in the assessment of good rather than acceptable welfare, and behaviours such as play, allogrooming and certain vocalisations could become increasingly important [4-7]. In the absence of clear indicator luxury behaviours, it may be enough to assess behavioural diversity as a measure of welfare (e.g. using the Shannon-Weaver diversity index) by identifying those systems where a greater spread across the behavioural repertoire is encouraged, a method increasingly employed in zoo collections (McCormick & Melfi, unpublished) [8]. The use of behavioural diversity as an assessment tool can also help to eliminate the risk of over-recording luxury behaviours that are acting as self-rewarding mechanisms in stressful situations. Behaviours that support the ability to cope with challenge. It may not be enough to simply identify the presence of behaviours indicative of positive emotions, but focus may also be required on identifying the existence of systems that allow animals to cope. Management systems do not need to be absent of any potential stressors – in fact this could be argued to result in a lack of stimulation – but should enable animals to cope with these acute events in a way that prevents a chronic stress situation from occurring. As such, the study and assessment of positive indicators of welfare should also include those behaviours / situations that allow coping. Studies in rats have identified that negative affective states are associated with faster startle responses and reduced anticipatory behaviours [1, 9] but investigations into the situations that link positive affective states to coping are limited. Previous social studies in domestic cattle have focused on the negative perspectives, i.e. dominance and aggression, but no work had been conducted on the potential positive benefits of social bonding. A large, dynamically managed, dairy cattle herd was studied to establish the existence of preferred partners according to proximity scorings. During these initial stages, it was established that heifers (52%, n=34) were significantly more likely to have one or more preferred partners compared to cows (32%, n=12) (X2 = 8.210, df=1, p=0.004) with relation to the probability of being associated with a particular individual – although it was suggested that this could have indicated that experience of repeated regroupings in cows had caused a dissolution of previously formed bonds. Following stage 1, commercial regrouping practices continued to affect the possible existence of preferred partnerships. During stage 2, six focal animals, previously identified as having a preferred partners (PP) that they were still housed alongside were separated off from the rest of the group for 30 minutes in a holding pen, either with their preferred partner or with a random individual from within the group. Three separation conditions were studied: 1. Focal animal (A) separated with their PP (B); 2. Focal animal (A) separated with a random individual (C) whilst B is released back to the home group; 3. Animal B separated with a random individual C whilst focal animal A is released back into the group. The heart rates of focal animal A during stage 1 and stage 2, and animal B during stage 3, were monitored using a Polar (Protrainer 5 Equine RS800) heart rate monitor, adapted for use in cattle, at 15 sec intervals. All protocols were approved by a Moulton College ethical committee. Heart rates differed significantly between stages (P=0.001) with focal animals (A) having lower heart rates when separated with their preferred partner (80.2 BPM) compared to being separated with a random individual (82.6 BPM). Interestingly, the partners’ heart rates when with a random individual (79.9 BPM) were lower than the focals’ in either situation. Although the actual difference in heart rates was small, the distinction was clear and this opens up further areas requiring research with regards to threshold levels beyond which chronic stress becomes physiologically damaging. There is also potential that the presence of any familiar cow could provide some degree of support but that the distinction lay within the level of familiarity. From these results it can be suggested that some individuals seem to benefit from having their preferred partner present during a potentially stressful situation. It could also be suggested that some individuals are more sensitive to stressful situations compared to others. When developing / assessing dairy management systems, those that support the formation of social bonding and subsequently manage animals in a way that these bonds can be maintained may in turn provide a higher welfare system by improving the coping ability of individuals. Conclusions Much emphasis has been placed on identifying indicators of poor welfare but the effective assessment of good welfare is an area gaining momentum both within academia and industry [10]. A wide range of behavioural methods exist that can be utilised as good welfare indicators in all animal management systems but the subtle nature of these indicators requires rigorous validation and development to create systems that can easily be employed by users on site. References 1. Boissy A, Manteuffel G, Jensen MB, Oppermann Moe R, Spruijt B, Keeling LJ, Winckler C, Forkman B, Dimitrov I, Langbein J, Bakken M, Veissier I, Aubert A. (2007) Assessment of positive emotions in animals to improve their welfare. Physiology & Behaviour 92: 375–397 2. Spruijt BM, van den Bos R, Pijlman FT. (2001) A concept of welfare based on reward evaluating mechanisms in the brain: anticipatory behavior as an indicator for the state of reward systems. Applied Animal Behaviour Science 72:145–71. 3. Jensen P, Toates FM. (1993) Who needs “behavioral needs”? Motivational aspects of the needs of animals. Applied Animal Behaviour Science 37:161–81

    Preliminary trend monitoring system data manager's guide

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    The functions and data base structures that the data base manager will be responsible for maintaining are documented. All normal and error sequences are included

    SAM 2 measurements of the polar stratospheric aerosol, volume 8

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    The Stratospheric Aerosol Measurement (SAM) 2 sensor aboard Nimbus 7 is providing extinction measurements of Antarctic and Arctic stratospheric aerosols with a vertical resolution of 1 km. Representative examples and weekly averages including corresponding temperature profiles provided by NOAA for the time and place of each SAM 2 measurement (Apr. 1982 - Oct. 1982) are presented. Contours of aerosol extinction as a function of altitude and longitude or time are plotted, and aerosol optical depths are calculated for each week. Typical values of aerosol extinction at 1.0 microns in the main stratospheric aerosol layer are approximately 4 to 6 times .0001/km at the beginning to 1 to 2 times .001/km at the end of the time period for the Antarctic region and approximately 1 to 3 times .001/km for the Arctic region throughout the time period. Stratospheric optical depths are about 0.002 to 0.009 for the Antarctic region and about 0.007 at the beginning to 0.024 at the end of the time period for the Arctic region. Polar stratospheric clouds were observed during the Antarctic winter, as expected. This report provides, in a ready-to-use format, a representative sample of the eighth 6 months of data to be used in atmospheric and climatic studies

    SAM 2 measurements of the polar stratospheric aerosol. Volume 3: October 1979 to April 1980

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    The Stratospheric Aerosol Measurement (SAM) II sensor is aboard the Earth-orbiting Nimbus 7 spacecraft providing extinction measurements of the Antarctic and Arctic stratospheric aerosol with a vertical resolution of 1 km. Representative examples and weekly averages of aerosol data and corresponding temperature profiles for the time and place of each SAM II measurement (Oct. 1979 through Apr. 1980) are presented. Contours of aerosol extinction as a function of altitude and longitude or time are plotted and weekly aerosol optical depths are calculated. Seasonal variations and variations in space (altitude and longitude) for both polar regions are easily seen. Typical values of aerosol extinction at the SAM II wavelength of 1.0 microns for this time period are 2 to 4 times .0001/km in the main stratospheric aerosol layer. Optical depths for the stratosphere are about 0.002 to 0.003, up slightly over normal background levels (due to the eruption of Sierra Negra, Nov. 1979). Polar stratospheric clouds at altitudes of about 22 km were observed during the Arctic winter. A ready-to-use format containing a representative sample of the third 6 months of data to be used in atmospheric and climatic studies is presented

    Simulating Cortical Feedback Modulation as Changes in Excitation and Inhibition in a Cortical Circuit Model.

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    Cortical feedback pathways are hypothesized to distribute context-dependent signals during flexible behavior. Recent experimental work has attempted to understand the mechanisms by which cortical feedback inputs modulate their target regions. Within the mouse whisker sensorimotor system, cortical feedback stimulation modulates spontaneous activity and sensory responsiveness, leading to enhanced sensory representations. However, the cellular mechanisms underlying these effects are currently unknown. In this study we use a simplified neural circuit model, which includes two recurrent excitatory populations and global inhibition, to simulate cortical modulation. First, we demonstrate how changes in the strengths of excitation and inhibition alter the input-output processing responses of our model. Second, we compare these responses with experimental findings from cortical feedback stimulation. Our analyses predict that enhanced inhibition underlies the changes in spontaneous and sensory evoked activity observed experimentally. More generally, these analyses provide a framework for relating cellular and synaptic properties to emergent circuit function and dynamic modulation

    Portable digital pressure indicator for calibrating magnetic tape recorders

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    The design of a portable Digital Pressure Indicator (DPI) to be used for calibrating the pressure systems on Langley's magnetic tape recorders is described. High-speed magnetic tape recorders require pressure (0 to 20 psig) for providing an air cushion across the tape guides and a slight vacuum (30 inch H2O) for maintaining the proper number of tape loops in the advance and feed chamber. The DPI is a hand-held device that can be quickly coupled to a magnetic tape recorder and includes a two-position switch for selecting either measured pressure or vacuum, to be displayed digitally in engineering units (psig or inches H2O). The DPI is currently in use in Langley's Analysis and Computation Division

    Hydrodynamic air lubricated compliant surface bearing for an automotive gas turbine engine. 1: Journal bearing performance

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    A 38.1 mm (1.5 inch) diameter Hydresil Compliant Surface Air Lubricated Journal Bearing was designed and tested to obtain bearing performance characteristics at both room temperature and 315 C (600 F). Testing was performed at various speeds up to 60,000 rpm with varying loads. Rotating sensors provided an opportunity to examine the film characteristics of the compliant surface bearing. In addition to providing minimum film thickness values and profiles, many other insights into bearing operation were gained such as the influence of bearing fabrication accuracy and the influence of smooth foil deflection between the bumps

    Relative intensity squeezing by four-wave mixing with loss: an analytic model and experimental diagnostic

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    Four-wave mixing near resonance in an atomic vapor can produce relative intensity squeezed light suitable for precision measurements beyond the shot-noise limit. We develop an analytic distributed gain/loss model to describe the competition of mixing and absorption through the non-linear medium. Using a novel matrix calculus, we present closed-form expressions for the degree of relative intensity squeezing produced by this system. We use these theoretical results to analyze experimentally measured squeezing from a 85^{85}Rb vapor and demonstrate the analytic model's utility as an experimental diagnostic.Comment: 10 pages, 5 figure

    Comment on: Diffusion through a slab

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    Mahan [J. Math. Phys. 36, 6758 (1995)] has calculated the transmission coefficient and angular distribution of particles which enter a thick slab at normal incidence and which diffuse in the slab with linear anisotropic, non-absorbing, scattering. Using orthogonality relations derived by McCormick & Kuscer [J. Math. Phys. 6, 1939 (1965); 7, 2036 (1966)] for the eigenfunctions of the problem, this calculation is generalised to a boundary condition with particle input at arbitrary angles. It is also shown how to use the orthogonality relations to relax in a simple way the restriction to a thick slab.Comment: 3 pages, LaTeX, uses RevTe

    Manipulating Tournaments in Cup and Round Robin Competitions

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    In sports competitions, teams can manipulate the result by, for instance, throwing games. We show that we can decide how to manipulate round robin and cup competitions, two of the most popular types of sporting competitions in polynomial time. In addition, we show that finding the minimal number of games that need to be thrown to manipulate the result can also be determined in polynomial time. Finally, we show that there are several different variations of standard cup competitions where manipulation remains polynomial.Comment: Proceedings of Algorithmic Decision Theory, First International Conference, ADT 2009, Venice, Italy, October 20-23, 200
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