Avian gait analysis

Modern broilers have difficulty walking, and there is ongoing debate as to whether the birds are in pain. Most gait analysis of poultry consists of visual assessment and scoring, and the results are therefore very subjective. In order to describe and quantify gait patterns accurately, a more objective method is required. Only then can differences between the gait of normal chickens and modem broilers be properly described, and attempts made to determine whether the observed gait patterns are the result of the conformation of the birds, or the presence of pain.Two methods were used in this research. The pedobarograph is a relatively novel method of gait analysis for animals which enables footfall patterns to be recorded, enabling spatial parameters (step length, width and angle) and plantar pressure patterns to be described and measured. A Kistler force plate was then used to measure the three - dimensional ground reaction forces (GRF's) produced during walking. Speed and cadence can be calculated using either system.Gait patterns are described for normal birds, and for different strains of broilers, raised on different feeding regimes. All the gait parameters were very variable, both between birds, and within the same bird, even when bodyweight and speed were controlled for. Despite the high variability, however, significant differences were identified in many of the gait parameters between the different groups.The vertical and craniocaudal GRF's of Brown Leghorns showed similar characteristics to those produced in human walking. The peak vertical forces were of a similar order of magnitude in the birds as in humans (125 -150 % bodyweight), and the peak craniocaudal forces, and rate of change of force, were closely tied to speed. All the GRF's in the birds increased significantly with increasing speed, except for braking rate (which was more variable) and stance time (which decreased significantly). The mediolateral forces were much greater in the birds than have been reported for other species, however, with peaks of 10 -22% bodyweight. Analysis of plantar pressures showed that the pressures were concentrated on the digital pads, with the lowest pressures on the metatarsal pad ( <131 kNm "2), and highest pressures on the medial toe (up to 218 kNm "2).Combined gait analysis and morphometric studies of ad libitum -fed selected broilers identified many ways in which their gait deviated from that of relaxed broilers and Brown Leghorns, in ways which would serve to increase stability and decrease stresses on the skeleton. The ad libitum -fed selected birds (compared to restricted -fed strain -mates and relaxed birds of the same weight), had more breast muscle anteriorly, and shorter, wider legs, but with immature bones, of lower % ash content. They moved more slowly, taking short steps, and positioned their feet wide apart and turned `toe -out' to increase their walking base. They kept their feet on the ground for longer, with short swing periods, and long double contact times. Decreasing the unstable periods of single support, and increasing the stance periods, reduces the peak forces on the skeleton. The slow speed and short steps also reduce the vertical excursions of the centre of gravity. The very wide walking base results in abnormally large mediolateral forces being required to move the centre of gravity over the stance leg, however, increasing the inefficiency of the gait, leading to fatigue. Mediolateral forces in ad libitum -fed selected birds averaged 17 -21% bodyweight at 6 weeks, compared to 10 -11% in the Brown Leghorns, and <5 -8% in humans (Biewener, 1992).Changes in the GRF's were also demonstrated in the slower growing (restricted -fed) broilers with age. In these birds, both the peak vertical forces and the peak mediolateral forces decreased with age, despite the fact that the birds increased in size (and girth) and their speed of movement remained similar. This indicates that the birds developed gait optimisations as they grew (as is the case with children), possibly because the slower growth allowed the body to develop more in proportion.Analysis of the gait of a small number of lame birds demonstrated marked differences in the spatial and force parameters between the sound and lame limb. The peak forces on the lame leg were dramatically reduced, and compensatory increases were seen in the GRF's of the sound limb. The birds used several methods to avoid fully loading the lame leg: flapping the wings to raise the centre of gravity, pushing up on the sound limb prior to placing the lame leg down, and flexing the lame limb as it starts to weightbear.There were no changes in the GRF's or temporal parameters of gait of broilers given analgesic (carprofen). Unfortunately, this does not prove conclusively that the birds were not in pain, as analgesic efficacy has not been validated in broilers, and it is also possible that the parameters under test do not change in the presence of pain. However the incidental finding of old blood in synovial fluid samples of over 50% of the ad libitum -fed broilers adds to the welfare concerns. A second interesting finding was the high alkalinity of the fluid (median pH 8.15 - 8.40), with the possible consequences on intra- articular pharmacodynamics. Although the analgesic study proved inconclusive, results of the gait and morphometric studies demonstrate that it is possible to explain the gait patterns of ad libitum -fed selected broilers based on their body conformation alone

A formalism for describing and simulating systems with interacting components.

This thesis addresses the problem of descriptive complexity presented by systems involving a high number of interacting components. It investigates the evaluation measure of performability and its application to such systems. A new description and simulation language, ICE and it's application to performability modelling is presented. ICE (Interacting ComponEnts) is based upon an earlier description language which was first proposed for defining reliability problems. ICE is declarative in style and has a limited number of keywords. The ethos in the development of the language has been to provide an intuitive formalism with a powerful descriptive space. The full syntax of the language is presented with discussion as to its philosophy. The implementation of a discrete event simulator using an ICE interface is described, with use being made of examples to illustrate the functionality of the code and the semantics of the language. Random numbers are used to provide the required stochastic behaviour within the simulator. The behaviour of an industry standard generator within the simulator and different methods of number allocation are shown. A new generator is proposed that is a development of a fast hardware shift register generator and is demonstrated to possess good statistical properties and operational speed. For the purpose of providing a rigorous description of the language and clarification of its semantics, a computational model is developed using the formalism of extended coloured Petri nets. This model also gives an indication of the language's descriptive power relative to that of a recognised and well developed technique. Some recognised temporal and structural problems of system event modelling are identified. and ICE solutions given. The growing research area of ATM communication networks is introduced and a sophisticated top down model of an ATM switch presented. This model is simulated and interesting results are given. A generic ICE framework for performability modelling is developed and demonstrated. This is considered as a positive contribution to the general field of performability research

Real space investigation of structural changes at the metal-insulator transition in VO2

Synchrotron X-ray total scattering studies of structural changes in rutile VO2 at the metal-insulator transition temperature of 340 K reveal that monoclinic and tetragonal phases of VO2 coexist in equilibrium, as expected for a first-order phase transition. No evidence for any distinct intermediate phase is seen. Unbiased local structure studies of the changes in V--V distances through the phase transition, using reverse Monte Carlo methods, support the idea of phase coexistence and point to the high degree of correlation in the dimerized low-temperature structure. No evidence for short range V--V correlations that would be suggestive of local dimers is found in the metallic phase.Comment: 4 pages, 5 figure

Effects of Terrorism Threat on Economic Preferences: The Role of Personality

Certain threats, such as terrorism tend to have a low probability of affecting us directly, yet reminders of them (such as media news) are striking. Could individuals with particular personality traits find them distractive from the usual priorities in daily decision-making? This study explored the putative effects of media-driven terrorism threat, on two economic preferences (risk aversion and delay discounting) - using a sample reasonably closely representative of a modern Western city. Participants (N = 78) higher on impulsivity showed lower risk-seeking under terrorism threat. Discussed are directions for further research and the implications for media coverage of terrorist threat

The Reinforcement Sensitivity Theory of Personality Questionnaire (RST-PQ): Development and Validation

We report the development and validation of a questionnaire measure of the revised reinforcement sensitivity theory (rRST) of personality. Starting with qualitative responses to defensive and approach scenarios modeled on typical rodent ethoexperimental situations, exploratory and confirmatory factor analyses (CFAs) revealed a robust 6-factor structure: 2 unitary defensive factors, fight–flight–freeze system (FFFS; related to fear) and the behavioral inhibition system (BIS; related to anxiety); and 4 behavioral approach system (BAS) factors (Reward Interest, Goal-Drive Persistence, Reward Reactivity, and Impulsivity). Theoretically motivated thematic facets were employed to sample the breadth of defensive space, comprising FFFS (Flight, Freeze, and Active Avoidance) and BIS (Motor Planning Interruption, Worry, Obsessive Thoughts, and Behavioral Disengagement). Based on theoretical considerations, and statistically confirmed, a separate scale for Defensive Fight was developed. Validation evidence for the 6-factor structure came from convergent and discriminant validity shown by correlations with existing personality scales. We offer the Reinforcement Sensitivity Theory of Personality Questionnaire to facilitate future research specifically on rRST and, more broadly, on approach-avoidance theories of personality

Supplemental Material for The Reinforcement Sensitivity Theory of Personality Questionnaire (RST-PQ): Development and Validation

We report the development and validation of a questionnaire measure of the revised reinforcement sensitivity theory (rRST) of personality. Starting with qualitative responses to defensive and approach scenarios modeled on typical rodent ethoexperimental situations, exploratory and confirmatory factor analyses (CFAs) revealed a robust 6-factor structure: 2 unitary defensive factors, fight–flight–freeze system (FFFS; related to fear) and the behavioral inhibition system (BIS; related to anxiety); and 4 behavioral approach system (BAS) factors (Reward Interest, Goal-Drive Persistence, Reward Reactivity, and Impulsivity). Theoretically motivated thematic facets were employed to sample the breadth of defensive space, comprising FFFS (Flight, Freeze, and Active Avoidance) and BIS (Motor Planning Interruption, Worry, Obsessive Thoughts, and Behavioral Disengagement). Based on theoretical considerations, and statistically confirmed, a separate scale for Defensive Fight was developed. Validation evidence for the 6-factor structure came from convergent and discriminant validity shown by correlations with existing personality scales. We offer the Reinforcement Sensitivity Theory of Personality Questionnaire to facilitate future research specifically on rRST and, more broadly, on approach-avoidance theories of personality

Thinking bigger: The Cronbachian paradigm & personality theory integration

Personality theories largely mirror disparities between fundamental paradigms that guide most psychology: one based upon Galton's emphasis on inter-individual differences and the lexical hypothesis; the other inspired by Wundt is focused upon intra-individual processes, such as temperament and Reinforcement Sensitivity Theory. Previous integrations of personality models using these paradigms failed to account for observed variance, suggesting model incommensurability. We propose that a broader conception-developed from Cronbach and colleagues' generalisability theory-provides an effective integrating framework, and show how Galtonian and Wundtian models may be assimilated within Cronbachian approaches. Additionally, Cronbachian models have novel practical implications. Application of the Cronbachian paradigm to personality will be challenging, but provides an opportunity to achieve genuine coherence in personality research

Fast microwave-assisted synthesis of Li-stuffed garnets and insights into Li diffusion from muon spin spectroscopy

Lithium-stuffed garnets attract huge attention due to their outstanding potential as solid-state electrolytes for lithium batteries. However, there exists a persistent challenge in the reliable synthesis of these complex functional oxides together with a lack of complete understanding of the lithium-ion diffusion mechanisms in these important materials. Addressing these issues is critical to realizing the application of garnet materials as electrolytes in all solid-state lithium-ion batteries. In this work, a cubic phase garnet of nominal composition Li6.5Al0.25La2.92Zr2O12 is synthesized through a microwave-assisted solid-state route for the first time, reducing considerably the reaction times and heating temperatures. Lithium-ion diffusion behavior is investigated by electrochemical impedance spectroscopy (EIS) and state-of-art muon spin relaxation (μSR) spectroscopy, displaying activation energies of 0.55 ± 0.03 eV and 0.19 ± 0.01 eV respectively. This difference arises from the high inter-grain resistance, which contributes to the total resistance in EIS measurements. In contrast, μSR acts as a local probe providing insights on the order of the lattice, giving an estimated value of 4.62 × 10−11 cm2 s−1 for the lithium diffusion coefficient. These results demonstrate the potential of this lithium-stuffed garnet as a solid-state electrolyte for all-solid state lithium-ion batteries, an area of growing interest in the energy storage community

Passive and Active Facebook Use Measure (PAUM): Validation and relationship to the Reinforcement Sensitivity Theory

The aims of this study were to design and validate a questionnaire to measure passive and active Facebook use, and to explore the associations of these factors with the Reinforcement Sensitivity Theory (RST) of personality. Passive Facebook use describes the consumption but not the creation of content, while active Facebook use describes active engagement with the site. As Facebook has many features, users may interact with the site differently, thereby creating conflicting results when general use measures are assessed independently. To address this issue, we developed a 13-item questionnaire which reflects three levels of Facebook engagement: Active social, Active non-social, and Passive use. These three multi-item scales demonstrate sufficient internal reliability and discriminant validity. To further investigate individual differences in Facebook use, we used regressions to assess the associations between RST and the factors of the Passive Active Use Measure (PAUM). Reward Reactivity was positively associated with both Active social and Passive use. Impulsivity and Goal-Drive Persistence were positively associated with Active non-social use. FFFS was positively associated with Passive use, and Reward Interest was positively associated with all three PAUM factors. The findings of this study highlight how individual differences impact the way users engage with Facebook