Publications by authors named "CA Weeks"

Injurious pecking, commonly controlled by beak trimming (BT), is a widespread issue in laying hens associated with thwarted foraging. This controlled study compared the effect in intact and beak-trimmed pullets of providing pecking pans to eight treatment flocks from six weeks of age. Flocks (mean size 6843) comprised eight British Blacktail, six Lohmann Brown and two Bovans Brown.

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To access resources in commercial laying houses hens must move between levels with agility to avoid injury. This study considered whether providing ramps during rear improved the ability of birds to transition between levels. Twelve commercial flocks (2000 birds/flock) on a multi-age site were examined between 1 and 40 weeks of age.

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The Hennovation project, an EU H2020 funded thematic network, aimed to explore the potential value of practice-led multi-actor innovation networks within the laying hen industry. The project proposed that husbandry solutions can be practice-led and effectively supported to achieve durable gains in sustainability and animal welfare. It encouraged a move away from the traditional model of science providing solutions for practice, towards a collaborative approach where expertise from science and practice were equally valued.

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Background: This study estimates the cost-effectiveness of patellar resurfacing in total knee arthroplasty (TKA).

Methods: We conducted a cost-effectiveness analysis using a decision analytic model representing a hypothetical TKA cohort, with or without patellar resurfacing, using data from the 2014 Australian Registry. The model represents 3 possible postoperative health states: (1) well, (2) patellofemoral pain, or (3) serious adverse event (any event resulting in a revision).

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Background: Laying hens are often kept in barn or free-range systems where they must negotiate level changes in the house to access resources. However, collisions and resultant keel fractures are commonplace. Producers sometimes add ramps to make raised areas more accessible but designs vary and very little research has investigated bird preference or behaviour when using different ramp designs, or the effect of ramp design on falls and collisions

Methods: Two ramp designs were studied in an experimental setting-a ramp made of plastic poultry slats (grid ramp, GR) and a ramp made of wooden rungs (ladder ramp, LR).

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1. In commercial free-range systems for laying hens, popholes to the outdoor range are often installed on one side of the house only. In multi-tier systems, it is possible that some individuals fail to access the range due to internal barriers to movement.

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Many structural variants of elastin-like polypeptides (ELPs), the genetically engineered equivalents of part of human elastin, currently are being investigated for drug delivery and tissue engineering. Here, we report preparation of six different aminated ELP conjugates via two strategies. In the first, a direct linking strategy was used to couple hydrophobic ELP with either polyethyleneimine, polylysine, or polyarginine.

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Culture conditions that induce hepatic spheroidal aggregates sustain liver cells with metabolism that mimics in vivo hepatocytes. Here we present an array of elastin-like polypeptide conjugate coating materials (Aminated-ELPs) that are biocompatible, have spheroid-forming capacity, can be coated atop traditional culture surfaces, and maintain structural integrity while ensuring adherence of spheroids over long culture period. The Aminated-ELPs were synthesized either by direct conjugation of ELP and various polyelectrolytes or by conjugating both ELP and various small electrolytes to the reactive polymer poly(2-vinyl-4,4-dimethyl azlactone) (PVDMA).

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The direct anterior approach for total hip arthroplasty (THA) requires the use of intraoperative imaging, exposing the patient and surgical team to radiation. The authors hypothesized that calculation of the preoperative pelvic tilt angle and communication of this value with the fluoroscopy technician may result in a decrease in intraoperative fluoroscopy use. The study also examined total radiation exposure during the procedure to ensure that it was within safe limits.

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Data from ten sources comprising 3,851 flocks were modelled to identify variation in levels of mortality in laying hens. The predicted increase with age was curvilinear with significant variation between the seven breed categories. Mortality was higher in loose housing systems than in cages and variable within system, confirming previous reports.

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Lameness is common in commercially reared broiler chickens but relationships between lameness and pain (and thus bird welfare) have proved complex, partly because lameness is often partially confounded with factors such as bodyweight, sex and pathology. Thermal nociceptive threshold (TNT) testing explores the neural processing of noxious stimuli, and so can contribute to our understanding of pain. Using an acute model of experimentally induced articular pain, we recently demonstrated that TNT was reduced in lame broiler chickens, and was subsequently attenuated by administration of Non-Steroidal Anti-Inflammatory Drugs (NSAIDs).

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Background: Despite the advent of locking plate techniques, proximal humeral fracture fixation can fail due to varus collapse, especially in osteoporotic bone with medial cortex comminution. This study investigated the effect of restoring the integrity of the medial column by fracture impaction and shaft medialization with locking plate fixation. This construct was compared with a traditional locking plate construct under conditions of varus cyclical loading.

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This study investigated the protective effects of an on-farm management package designed to reduce injurious pecking (IP) in loose-housed laying hens. A systematic review of scientific literature generated 46 potentially protective management strategies. Bespoke management packages were designed for treatment flocks (TF) using these management strategies.

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Though two-dimensional systems have yielded some success in deriving morphological and functional markers of hepatocyte culture, they largely fail to capture the three-dimensional organization, long-term viability, and functionality of the hepatic tissue. We have engineered a system for inducing self-assembly of model H35 rat hepatoma spheroids using a copolymer comprised of biocompatible elastin-like polypeptide (ELP) chemically conjugated to positively charged polyethyleneimine (PEI). We have achieved a conjugation ratio of 30 mol %, though our studies analyzing spheroid organization kinetics indicate conjugate ratios of 5 mol % and greater to be optimal for cell culture based on least variability in spheroid sizes and minimum incidence of overgrown aggregates.

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Several studies in the past have formed 3-dimensional (3D) spheroids of primary hepatocytes in suspension culture. Unfortunately, primary hepatocytes in a suspension environment tend to lose their differentiated function over time, generally due to damage from fluid shear stress and eventual spheroid settling. We have therefore created a novel suspension culture system, by seeding H35 rat hepatoma cells, a hepatocyte-derived cell line, in a 24-well tissue culture polystyrene (TCPS) plate placed atop an orbital shaker to create 3D spheroids.

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Leg health of intensively reared broiler chickens is a significant problem, yet little is known regarding the nature of lameness-associated pain. Kinematic changes in gait have been reported in naturally lame broilers following subcutaneous non-steroidal anti-inflammatory drug (NSAID) administration, compared to a placebo group. In the current study, an extensive range of gait parameters were defined using a commercial motion-capturing system to record three-dimensional temporospatial information from walking broilers pre- and post-treatment.

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Changes in module drawer temperature and relative humidity were monitored for 24 commercial loads of hens. Mathematical models revealed significant differences in predicted drawer temperature depending on their location and the outside environmental temperature. Higher predicted temperatures were found in uppermost drawers of the top modules at the front of the lorry, and lower temperatures in drawers on the outer sides of modules and in those drawers in modules next to the back of the lorry in both the upper and lower modules during transport.

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This is the first time that gait characteristics of broiler (meat) chickens have been compared with their progenitor, jungle fowl, and the first kinematic study to report a link between broiler gait parameters and defined lameness scores. A commercial motion-capturing system recorded three-dimensional temporospatial information during walking. The hypothesis was that the gait characteristics of non-lame broilers (n = 10) would be intermediate to those of lame broilers (n = 12) and jungle fowl (n = 10, tested at two ages: immature and adult).

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The average mortality for end of lay hens dead on arrival (DOA) was 0.27 per cent (median 0.15 per cent) in a survey of 13.

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Behavioural signs of pain are difficult to quantify and interpret in animals. Nociceptive threshold testing is therefore a useful method for examining the perception and processing of noxious stimuli underlying pain states. Devices were developed to measure response thresholds to quantified, ramped mechanical and thermal nociceptive stimuli applied to the leg or keel of unrestrained birds.

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Levels of sound intensity were measured over periods of 24 hours in 34 abattoir lairages in England and Wales. The mean integrated range in 12 cattle lairages was 52 to 79 dB(A), in 11 sheep lairages, 45 to 76 dB(A) and in 11 pig lairages, 46 to 87 dB(A). In general, the pig lairages were the noisiest, with spot peak recordings of up to 110 dB(A).

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In 2004, a survey of 12 metals was carried out in six rural and six urban allotment sites across the UK. A total of 215 samples of vegetables and 36 samples of soft fruit were analysed using ICP-MS, and 51 samples of soil using ICP-OES. On a fresh weight basis, Cu levels in produce ranged 0.

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Study Design: Retrospective chart review.

Objectives: To determine the prevalence of fatigue in an outpatient spinal cord injury population and to examine the clinical variables contributing to that fatigue.

Setting: GF Strong Rehabilitation Centre, Vancouver, British Columbia, Canada.

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A survey of 12 metals including lead (Pb), copper (Cu), cadmium (Cd), mercury (Hg), arsenic (As) and platinum (Pt) was carried out using ICP-MS in 34 samples of wild fungi and 48 samples of wild blackberries collected from sites across the UK. On a fresh weight basis (mg/kg) levels of Pb were in the range 0.003-5.

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A new method for assessing the severity of lameness in broiler chickens is described. The length of time that birds remained standing in shallow water was measured and the results were compared with the results of conventional gait scoring. There was a highly significant (P < 0.

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