78 research outputs found
Development of a method to identify foot strike on an arena surface: application to jump landing
Foot strike can be difficult to determine using kinematics alone, particularly when studying equine activities on more compliant surfaces, so this study was done with the aim of developing and validating a method to determine foot strike on an arena surface that can be used in conjunction with kinematics alone, and of applying the method in the context of measuring foot strike during jump landing on an arena surface. A low-cost contact mat was developed. The timing of the contact mat switching âonâ was compared to the timing of a force platform onset of 20 N, load and loading rate at foot strike. Two groups of 25 participants were used in two separate studies to validate the contact mat: the first measured the difference in timing with respect to two different activities (running and stepping down from a box), and the second measured the difference in timing with respect to 1- and 2-cm depths of an arena surface during running. In a third study, the mat was used to measure leading limb foot strike of six horses during jump landing, and these data were compared to kinematics from a palmar marker on the hoof wall. All data were recorded at 500 Hz. A consistent difference in delay was found between the mat and force platform onset, and as a result, no significant differences (P>0.05) in timing delay between different loading rates or depths were found. During jump landing, foot strike (determined from the mat) occurred after the vertical velocity minima and the acceleration maxima for the hoof marker, but it occurred before the point where the rate of vertical displacement began to reduce. In conclusion, further work is needed to enhance these techniques, but these preliminary results indicate that this method may be effective in determining foot strike for field-based applications
Operational temperatures of all-weather thoroughbred racetracks influence surface functional properties
The surface temperature of all-weather racetracks has previously been correlated to speed. However specific functional properties such as grip, cushioning and impact firmness have not been directly compared to environmental conditions. The objective of this study was to assess how temperature influences functional properties of racetracks, and categorise surface wax binders according to first thermal transition peak, and compare responses at different operational temperatures. Functional properties were determined for UK all-weather racetrack surfaces (n = 6) using mechanical testing equipment which assess the loads experienced by the forelimb at gallop (randomised block design). Tests were carried out using latex lined moulds, embedded within a test box with a predefined boundary at 0 °C, 20 °C and 40 °C. Wax binders underwent differential scanning calorimetry to identify thermal transition peaks. Changes in operational temperatures significantly influenced surface responses when a wax binder was part of the composition. Temperature was a factor that significantly contributed to the variation found in horizontal grip (F2, 237 = 65.69, P < 0.001), cushioning (F2, 237 = 58.24, P < 0.001), impact firmness (F2, 237 = 28.02, P < 0.001) and rotational grip (F12, 65 = 9.45, P < 0.001). Using a test box meant individual racetracks were generalised but this enabled conditions to be controlled. Colder temperatures demonstrated higher surface hardness and shear resistance that may increase risk of musculoskeletal injury although this was not measured here. Awareness of the effect temperature has on specific track behaviour allows maintenance protocols to be further developed to improve consistency when temperatures change, with the aim of improving safety
Standards for data acquisition and softwareâbased analysis of in vivo electroencephalography recordings from animals. A TASK1âWG5 report of the AES/ILAE Translational Task Force of the ILAE
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139127/1/epi13909.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139127/2/epi13909_am.pd
Orally Administered P22 Phage Tailspike Protein Reduces Salmonella Colonization in Chickens: Prospects of a Novel Therapy against Bacterial Infections
One of the major causes of morbidity and mortality in man and economically important animals is bacterial infections of the gastrointestinal (GI) tract. The emergence of difficult-to-treat infections, primarily caused by antibiotic resistant bacteria, demands for alternatives to antibiotic therapy. Currently, one of the emerging therapeutic alternatives is the use of lytic bacteriophages. In an effort to exploit the target specificity and therapeutic potential of bacteriophages, we examined the utility of bacteriophage tailspike proteins (Tsps). Among the best-characterized Tsps is that from the Podoviridae P22 bacteriophage, which recognizes the lipopolysaccharides of Salmonella enterica serovar Typhimurium. In this study, we utilized a truncated, functionally equivalent version of the P22 tailspike protein, P22sTsp, as a prototype to demonstrate the therapeutic potential of Tsps in the GI tract of chickens. Bacterial agglutination assays showed that P22sTsp was capable of agglutinating S. Typhimurium at levels similar to antibodies and incubating the Tsp with chicken GI fluids showed no proteolytic activity against the Tsp. Testing P22sTsp against the three major GI proteases showed that P22sTsp was resistant to trypsin and partially to chymotrypsin, but sensitive to pepsin. However, in formulated form for oral administration, P22sTsp was resistant to all three proteases. When administered orally to chickens, P22sTsp significantly reduced Salmonella colonization in the gut and its further penetration into internal organs. In in vitro assays, P22sTsp effectively retarded Salmonella motility, a factor implicated in bacterial colonization and invasion, suggesting that the in vivo decolonization ability of P22sTsp may, at least in part, be due to its ability to interfere with motility⊠Our findings show promise in terms of opening novel Tsp-based oral therapeutic approaches against bacterial infections in production animals and potentially in humans
Measuring hoof slip of the leading limb on jump landing over two different equine arena surfaces
The amount of hoof slip at the moment of impact can cause musculoskeletal injuries to the horse. Risk of injury is influenced by surface properties, however there is limited understanding of the effect on hoof slip during jump landing. The objectives of this study were to compare hoof slip on two different surfaces and investigate relationships between hoof slip and surface properties. A contact mat and hoof reference marker were designed and validated, the former to indicate the moment of impact and the latter to provide a visible reference marker on the lateral hoof wall. The leading right forelimb of six horses was recorded during jump landing on two different surfaces. Five trials, plus one where the forelimb landed on a contact mat were recorded at 500 Hz using a calibrated high speed camera positioned perpendicular to landing. Surface traction, hardness and penetration were measured between horses. Horizontal displacement of the hoof reference marker was plotted and smoothed with a Butterworth filter at 25 Hz cut off. Hoof slip was measured from impact to mid-stance. Data were analysed using ANOVA and Pearson correlations. A significant difference in hoof slip (10% wax=4.9 ± 2.1 cm and, 3% wax=7.4 ± 3.6 cm) was found between the two surfaces (P<0.01). In addition, hoof slip was correlated with all surface measurements (hardness, traction and penetrability) on the 10% wax surface, but none on the 3% wax surface. Wax content appears to influence hoof slip during jump landing as greater hoof slip was measured on a 3% wax surface and variability on this surface was greater for the group. The results suggest that wax content influenced surface properties and on the 3% wax surface the greater variability in hardness and traction influenced the consistency with which the horses jumped upon it
Effect of some cationic surfactants on an oil/water emulsion stabilized by dodecyl benzene sulphonate
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