bluuebunny/crossref_metadata_2025_split huggingface dataset:
Physical, acid–base and electrolyte changes in horses competing in Training, Preliminary and Intermediate horse trials
Authors: Foreman JH , Waldsmith JK , Lalum RB 
Published: May 2004

AbstractThe objective of this experiment was to compare the physiological changes that occurred in horses competing in the cross-country portion of Training, Preliminary and Intermediate horse trials. The hypothesis was that temperature (T), heart rate (HR), respiratory rate (RR), and on-site acid–base and electrolyte monitoring would allow differentiation between difficulty levels in horse trials. Sixteen client-owned horses competing at the Trojan-Horse Spring Horse Trials in Cave Creek, Arizona, USA, were studied. T, HR, RR and anaerobic lithium-heparinized jugular venous samples were obtained before, and 1–2 min after, cross-country exercise. Samples were analysed for blood gases (body temperature-corrected) and concentrations of sodium ([Na+]), potassium ([K+]), chloride ([Cl−]), ionized calcium ([Ca2+]i), blood urea nitrogen ([BUN]) and glucose ([GLC]) using a point-of-care analyser. Results were compared using analysis of variance with the level of significance set atP<0.05. In all groups, exercise increased T, HR, RR, packed cell volume and haemoglobin concentration, and decreased partial pressure of CO2(PCO2), [total CO2concentration], bicarbonate concentration ([HCO3−]) and [Ca2+]i(P<0.05). Post-exercise RR was higher, and pH, PCO2, [tCO2], [HCO3−] and base excess were lower, in Intermediate and sometimes Preliminary horses compared with Training horses (P<0.05). It was concluded that horse trials caused milder, but otherwise similar, physical, blood gas and electrolyte changes to those observed in complete three-day events. Physical and point-of-care plasma acid–base and electrolyte monitoring allowed differentiation between horses competing at various levels of difficulty in a horse trial.
Effect of age on locomotion of Standardbred trotters in training
Authors: Leleu C , Cotrel C , Barrey E 
Published: May 2004

AbstractIn Standardbreds, the main aim of early training (begun during the growth period) is the mechanization of athletes leading to a particular gait called the ‘flying trot’. The present cross-sectional study was undertaken to investigate the biomechanical and physiological factors involved in this gait change, and aimed to analyse the effect of age on gait and energetic variables in a population of Standardbred horses under training. One hundred and forty-three horses aged from two to seven years were tested on a track at three speeds (8.5, 10 and 11.6 m s−1) with a gait-analysis system. Gait variables (temporal and linear variables, symmetry, regularity, two-beat rhythm, dorso-ventral, longitudinal and lateral activities) were compared between four age groups (two-, three-, four-, and five-year-olds and above). After a standardized exercise test, two energetic variables (V4andV200) were also compared between these groups. Most variables were influenced by age/training status. The results indicated that, from young to mature racehorses, stride length and duration increase; and gait becomes more symmetric and more regular. We also observed a decrease in dorso-ventral, longitudinal and lateral activities, i.e. a decrease of thoracic displacements. These differences could be elucidated at slow speed and were still obvious at high speed.V4andV200also increased significantly with age/training status. All of these results indicate an improvement in co-ordination and a decrease in metabolic cost with increasing age/training status. Thus gait acquisition could be related to an improvement in trotting efficiency.
Effects of intra-articular hyaluronic acid onex vivoresponses by third carpal bone cartilage from horses with experimentally induced synovitis
Authors: Palmer Jan L , Mansour Joseph , Malemud Charles J , Bertone Alicia L 
Published: May 2004

AbstractWe studied the extent to which intra-articular hyaluronic acid (HA) administered to horses with experimentally induced synovitis in the third middle carpal joint altered cartilage proteoglycans (PGs) and the biomechanical properties of the third carpal bone. Intra-articular HA (Hylartin-V®) was administered to the middle carpal joints of healthy horses before and after the induction of synovitis byEscherichia colilipopolysaccharide (LPS). Two groups of horses received intra-articular HA only, with evaluation 2 and 6 weeks later (group 2 and group 4). Two other groups (group 1 and group 3) received LPS followed by intra-articular HA and evaluation 2 and 6 weeks later.Ex vivothird carpal bone cartilage PG synthesis was measured by35SO4incorporation and third carpal bone cartilage PG content was determined by an assay for glucuronic acid. Biomechanical properties were measured by indentation testing. At the 2-week evaluation, HA did not ablate the quantitative reduction in PG synthesis and PG content in animals with experimental synovitis. However, by 6 weeks, there was a significant rebound effect in that PG synthesis and PG content were elevated in horses with experimental synovitis that had received intra-articular HA, compared with horses that had received HA only for that period of time. There were also alterations in the gel filtration profiles of newly synthesized PGs on Sepharose CL-2B among the groups. However, there were node novoPG species associated with any of the treatments. Furthermore, we found that the biomechanical properties of third carpal bone cartilage were not altered in any of the groups. These studies showed that intra-articular HA administered to horses with experimentally induced synovitis did not provide short-term (i.e. 2-week) benefit to third carpal bone cartilage PG synthesis. However, a long-term benefit of intra-articular HA may occur after the acute effects of synovitis on PG synthesis and PG content subside.
Effects of hoof shape, body mass and velocity on surface strain in the wall of the unshod forehoof of Standardbreds trotting on a treadmill
Authors: Thomason JJ , Bignell WW , Batiste D , Sears W 
Published: May 2004

AbstractThe purpose of this work is to investigate the effects of body mass (BM), velocity (V), and hoof shape on compressive surface strains in the wall of the front hoof at the trot. Toe angle (TA), heel angle (HA), toe length (TL), medial and lateral wall length (MWL, LWL) and BM were measured for nine adult, unshod Standardbreds. Five rosette gauges were glued around the circumference of the left forehoof of each animal which was then trotted on a treadmill at a set range of velocities from 3.5 to 7.5 m s−1. Analysis of variance (ANOVA) of principal compressive strainsɛ2at midstance identified that all primary variables (BM,V, TA, HA, etc.) had a significant effect as did the interactions of TA×HA and BM×TA. These significant variables explained over 96% of the variation inɛ2. Multiple regression ofɛ2on these variables gave equations which accurately predictedɛ2within 3%, but the individual coefficients did not accurately describe how each variable affectedɛ2. Further tests using bivariate regression gave equations that enabledɛ2data to be standardized for BM andVat the gauge locations used here. Strainɛ2increased linearly with mass and curvilinearly with velocity (ɛ2∝V+V2), and both caused redistribution of strain to the dorsum and lateral quarter. Variation in each shape variable caused redistribution rather than simple increase or decrease in strains. The primary conclusion with regard to hoof shape is that the effects of change in any one measurement on strain magnitudes are affected by the values of all other measurements. Resolving the interplay among measurements in their effects onɛ2will need a considerably larger sample size than that used here.
Time course and magnitude of changes in total body water, extracellular fluid volume, intracellular fluid volume and plasma volume during submaximal exercise and recovery in horses
Authors: Lindinger Michael I , McKeen Gloria , Ecker Gayle L 
Published: May 2004

AbstractThe purpose of the present study was to determine the time course and magnitude of changes in extracellular and intracellular fluid volumes in relation to changes in total body water during prolonged submaximal exercise and recovery in horses. Seven horses were physically conditioned over a 2-month period and trained to trot on a treadmill. Total body water (TBW), extracellular fluid volume (ECFV) and plasma volume (PV) were measured at rest using indicator dilution techniques (D2O, thiocyanate and Evans Blue, respectively). Changes in TBW were assessed from measures of body mass, and changes in PV and ECFV were calculated from changes in plasma protein concentration. Horses exercised by trotting on a treadmill for 75–120 min incurred a 4.2% decrease in TBW. During exercise, the entire decrease in TBW (mean±standard error: 12.8±2.0 l at end of exercise) could be attributed to the decrease in ECFV (12.0±2.4 l at end of exercise), such that there was no change in intracellular fluid volume (ICFV; 0.9±2.4 l at end of exercise). PV decreased from 22.0±0.5 l at rest to 19.8±0.3 l at end of exercise and remained depressed (18–19 l) during the first 2 h of recovery. Recovery of fluid volumes after exercise was slow, and characterized by a further transient loss of ECFV (first 30 min of recovery) and a sustained increase in ICFV (between 0.5 and 3.5 h of recovery). Recovery of fluid volumes was complete by 13 h post exercise. It is concluded that prolonged submaximal exercise in horses favours net loss of fluid from the extracellular fluid compartment.
Quantification of three-dimensional skin displacement artefacts on the equine tibia and third metatarsus
Authors: Lanovaz Joel L , Khumsap Siriporn , Clayton Hilary M 
Published: May 2004

AbstractRoutine study of three-dimensional (3D) tarsal kinematics is hampered by errors due to the displacement of skin surface-tracking markers relative to the underlying bones. Reliable kinematics can be obtained with bone-fixed markers, but an accurate, non-invasive method would have more applications. Simultaneous kinematic data from skin-based and bone-fixed markers attached to the tibia and third metatarsus were collected from three trotting subjects. The motion of the skin-based markers was extracted relative to the underlying bone motion tracked using the bone-fixed markers. The 3D skin displacement patterns for the skin-based markers were parameterized using a truncated Fourier series model. These displacements were expressed in terms of the local coordinate system for each bone. Skin displacement artefacts were observed in all three axes of each bone segment, with the largest displacements occurring at the proximal tibia. The mean skin displacement amplitudes in the tibia were 6.7%, 3.2% and 10.5% of segment length, and for the third metatarsus were 2.6%, 1.4% and 3.8% of segment length, for the craniocaudal, mediolateral and longitudinal segment axes, respectively. Skin displacement patterns could be expressed concisely using the Fourier series model. Displacements were also consistent between subjects, which should allow them to be used as a basis for developing a correction procedure for 3D tarsal joint kinematics.
Carbohydrate metabolism in exercising horses
Authors: Jose-Cunilleras E , Hinchcliff KW 
Published: May 2004

AbstractCarbohydrate and fat are the predominant sources of energy during exercise in mammals. Carbohydrates, such as muscle glycogen and plasma glucose, and fats from adipose tissue and intramuscular triglycerides are oxidized during exercise in amounts and proportions that vary depending on the exercise intensity, level of fitness and nutritional status. In horses, muscle glycogen, and to a lesser extent plasma glucose, are oxidized in substantial amounts during low-, moderate- and high-intensity exercise. Carbohydrate availability to skeletal muscle affects exercise performance in humans, however this relationship is not well outlined in horses. Glucose supplementation by intravenous administration during exercise in horses increases duration of moderate-intensity exercise. However, the effect of glucose supplementation by ingestion of a soluble carbohydrate-rich meal prior to exercise on athletic performance has not been established in horses. Low muscle glycogen concentrations prior to exercise in horses are associated with decreased time to exhaustion at moderate- and high-intensity exercise. Nutritional interventions intended to enhance muscle glycogen resynthesis have proved less successful in horses than in other species. Replenishment of muscle glycogen after strenuous exercise in horses is not complete until 48–72 h after exercise, whereas in humans and laboratory animals it is complete by 24 h. The slower rate of muscle glycogen replenishment after exercise in horses may be related to an inherent lower ability to digest starch and other sources of glucose, a lower ability to synthesize muscle glycogen, or both. The aim of this review is to describe the present understanding of carbohydrate metabolism in the exercising horse, its implications on nutrition and athletic performance, and to contrast it with that in other species.
Muscle injury and antioxidant status in sled dogs competing in a long-distance sled dog race
Authors: Hinchcliff KW , Constable PD , DiSilvestro RA 
Published: May 2004

AbstractExercise is associated with an increase in the production of oxidants that may be instrumental in the development of exertional rhabdomyolysis. We speculated that participation in a long-distance sled race would alter antioxidant capacity of dogs, in conjunction with increases in indices of rhabdomyolysis. The objective was to determine the effect of participation in a long-distance sled dog race on antioxidant capacity and plasma creatine kinase (CK) activity in sled dogs. This was a prospective, longitudinal study on a convenience sample of 57 Alaskan sled dogs participating in a 1600 km sled dog race. Blood samples were collected before racing (31 dogs) and after racing (39 dogs) for measurement of plasma vitamin E concentration; CK, aspartate aminotransferase (AST) and caeruloplasmin (CER) activity; and red-blood-cell (RBC) glutathione peroxidase (GPX) and superoxide dismutase (SOD) activity. CER and GPX activities after the race were 26% and 14% lower, respectively, than before racing whereas CK and AST were 300% and 170% greater. There was no change in plasma vitamin E concentration or RBC SOD activity. We conclude that completion of a long-distance sled dog race involving prolonged and repeated submaximal exercise results in a reduction in enzymatic antioxidant activity in the blood of sled dogs.
Temporal variables of the canter of the Tennessee Walking Horse
Authors: Splan RK , Hunter HB 
Published: May 2004

AbstractTemporal stride characteristics of the canter were compared between performance-shod (PS) and light-shod (LS) Tennessee Walking Horses, which generally differ in training and shoeing methods. Four consecutive strides for ten PS and ten LS horses were filmed (30 Hz), and frame-by-frame analysis performed to determine stride duration and individual limb stance duration. Also analysed was the percentage of stride duration devoted to single, bipedal or tripedal limb support. Footfall sequence for PS was trailing hind (TrH), leading hind (LdH), trailing fore (TrF) and leading fore (LdF), whereas footfall sequence for LS horses varied, with the majority of LS performing a sequence of TrH–TrF–LdH–LdF. Stride duration was greater for PS. As a percentage of stride duration, PS demonstrated greater duration of TrF and LdF, while LS demonstrated greater LdH duration. Hind and fore single limb support, and tripedal support, were greater for LS; however, PS utilized bipedal support to a larger extent than LS. Hind or forelimb bipedal support was demonstrated only in PS, while only LS demonstrated lateral bipedal support. Thus, while both performance- and light-shod Tennessee Walking Horses perform the canter, temporal variables for this gait differ dramatically between the two groups.
A simple field technique for estimation of body surface area in horses and ponies
Authors: Sneddon JC , Walton R , Bond A 
Published: May 2004

AbstractThis study aimed to produce a weight-independent algorithm for determination of body surface area (BSA; cm2) to within 5% accuracy of the directly determined value in selected horses and ponies under field conditions. Quantification of BSA in equines has applications in the fields of energy budgeting, growth, thermoregulation, conformation and drug kinetics. A simple algorithm for determining BSA to ±5% accuracy was produced for Shetland ponies, Shire horses, Welsh Mountain Section A ponies and Hanoverian mature horses and foals. The accuracy of the method was ±8% for Welsh Mountain-type ponies and Hanoverian two-year-olds. The data were produced by tiling of the shoulder region on one side of the animal with chalk and adapting a simple geometrical integrative technique. Linear anthropometric measurements were of limited use in predicting BSA in that they produced algorithms of ±5% accuracy for ponies of uniform conformation only (Welsh Mountain Section A ponies). The relevant equations were:for Arab-based breeds (Welsh Mountain-type and Section A ponies and Hanoverian horses and foals) andfor UK native breeds (Shetland ponies and Shire horses), where ‘surface area of shoulder region on one side’ was defined by the anterior margins of thesupraspinatusanddeep pectoral, and the posterior margin of thetricepsmuscles. This tiling procedure fulfilled the aim of the study and also provided quantitative information on proportional differences in areas of body regions between and within these selected breeds.
Current concepts of oxygen transport during exercise
Authors: Poole DC 
Published: May 2004

AbstractThis brief review examines the athletic potential of mammals in general and the horse in particular as it relates to oxygen (O2) transport and utilization. The horse has been bred selectively for over six millennia based upon its ability to run fast. Whereas this has optimized cardiovascular and muscle function and the capacity to deliver and utilize O2, it has resulted in lung failure during intense exercise. Horses in their athletic prime are considered and attention is focused on their maximal capacities as related to O2transport, irrespective of ageper se. Following a few comments on the history of O2, this review moves from established principles of O2transport at the integrative organ level to the microcirculation and the processes and principles that govern O2offloading, where much remains to be discovered. Four principal questions are addressed: (1) as an athlete, what are the most outstanding physiological characteristics of the horse? (2) what anatomical and physiological capacities facilitate this superlative performance and such prodigious O2fluxes (i.e. maximal VO2)? (3) do cardiovascular dynamics or intramuscular energetic processes limit VO2kinetics (i.e. the speed at which VO2increases at the onset of exercise)? VO2kinetics determine the size of the O2deficit and as such represent an important determinant of muscle metabolism and fatigue; and (4) what determines the efficacy of muscle microcirculatory O2exchange?
Effect of detomidine on postural sway in horses
Authors: Bialski D , Lanovaz JL , Bohart GV , Mullineaux DR , Clayton HM 
Published: May 2004

AbstractThe objective of this study was to apply postural sway analysis to measure balance deficits after intravenous administration of detomidine. Six healthy horses were treated intravenously with detomidine (10 μg kg−1, 20 μgkg−1) and saline in random order, with three days between treatments. Postural sway was measured immediately after administration and at 15 min intervals until 120 min had elapsed. Horses stood squarely with all four hooves on a force platform, while the location of the centre of pressure (COP) was recorded continuously for 10 s at 1000 Hz. Five 10 s recordings were analysed and average values calculated for mediolateral COP range of motion, craniocaudal COP range of motion, mean COP radius, COP area and mean COP velocity. All COP variables increased immediately after sedation, but generally returned to normal limits within 15 and 30 min of detomidine administration at 10 and 20 μg kg−1, respectively. The head was lowered for at least 90 min after administration. Balance is affected by detomidine and normal balance is regained later after a higher dose. Procedures requiring balance should not be performed within 15–30 min of detomidine administration. COP variables are a good indicator of the effect of sedation on postural sway, but head position is not.
Correlation of quantitative ultrasound measurements with material properties and bone mineral density in the equine metacarpus
Authors: Whan G , Runciman J , Hurtig M 
Published: May 2004

AbstractThis study explored the relationship between speed-of-sound (SOS) measurements and the material properties of metacarpal bones in order to validate a device that uses linear unicortical transmission of ultrasound. SOS, ultimate tensile strength and modulus of elasticity were determined at nine experimental sites. Measurements of SOS and bone mineral density were collected at three of the nine experimental sites. Twenty-five equine metacarpal (MC3) bones were used. Micro-computerized tomography was used to validate testing protocols. SOS measurements were highly site- and horse-dependent. One or more statistically significant correlations were found with ultimate tensile strength, modulus of elasticity and bone mineral density in four of the nine experimental sites. A previously described pattern of high lateral and medial cortical stiffness and SOS was found in the mid-diaphysis that correlated with bone mineral density (r2=0.25,P<0.01) and modulus of elasticity (r2=0.14,P<0.05). SOS and ultimate tensile strength correlated strongly in the distal dorsal metacarpus (r2=0.47,P<0.001). Lateral and medial distal-level sites just above the fetlock joint had a variable amount of cancellous bone, reducing the ultimate strength of these sites. The study indicates that quantitative ultrasound is sensitive to differences in the quality of equine metacarpal bone, so this technique may be useful for monitoring adaptation to exercise and bone development.
A statistical framework for genomic data fusion
Authors: Lanckriet Gert R. G. , De Bie Tijl , Cristianini Nello , Jordan Michael I. , Noble William Stafford 
Published: May 2004

Abstract
Motivation: During the past decade, the new focus on genomics has highlighted a particular challenge: to integrate the different views of the genome that are provided by various types of experimental data.
Results: This paper describes a computational framework for integrating and drawing inferences from a collection of genome-wide measurements. Each dataset is represented via a kernel function, which defines generalized similarity relationships between pairs of entities, such as genes or proteins. The kernel representation is both flexible and efficient, and can be applied to many different types of data. Furthermore, kernel functions derived from different types of data can be combined in a straightforward fashion. Recent advances in the theory of kernel methods have provided efficient algorithms to perform such combinations in a way that minimizes a statistical loss function. These methods exploit semidefinite programming techniques to reduce the problem of finding optimizing kernel combinations to a convex optimization problem. Computational experiments performed using yeast genome-wide datasets, including amino acid sequences, hydropathy profiles, gene expression data and known protein–protein interactions, demonstrate the utility of this approach. A statistical learning algorithm trained from all of these data to recognize particular classes of proteins—membrane proteins and ribosomal proteins—performs significantly better than the same algorithm trained on any single type of data.
Availability: Supplementary data at http://noble.gs.washington.edu/proj/sdp-svm