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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Occlusion of the Internal Carotid Artery of Horses: Evaluation of a Technique Designed to Prevent Epistaxis Caused by Guttural Pouch Mycosis

Cheramie, Hoyt Stephen 16 December 1998 (has links)
In six, healthy, adult horses, the origin of the left internal carotid artery was isolated via a modified hyovertebrotomy approach. Normograde blood flow was occluded by placement of a tourniquet on the artery near its origin. Lumenal access was gained through placement of a distally directed introducer sheath and retrograde blood flow from the cerebral arterial circle was confirmed. An 8.5 mm diameter detachable latex balloon loaded onto a carrier catheter and placed within a guiding catheter was introduced into the internal carotid artery through the introducer sheath and advanced to the target occlusion site (the proximal curve of the sigmoid flexure of the internal carotid artery). The balloon was inflated with 0.5 ml of a radiopaque solution. Correct placement and inflation of the balloon were confirmed by intraoperative radiography. The balloon was then released and the guiding and carrier catheters withdrawn. Immediate embolization of the distal internal carotid artery was determined by lack of retrograde blood flow through the introducer sheath. The introducer sheath was withdrawn from the vessel and the proximal tourniquet was replaced with two ligatures. Horses were euthanized on day 30 and detailed gross and histopathologic examinations were performed. The balloons were easily placed into the target site and produced immediate occlusion of retrograde flow from the cerebral arterial circle. All balloons remained inflated in their original position throughout the study period. Mature thrombus formation and absence of clinically significant inflammation were consistent findings in all occluded internal carotid arteries at gross necropsy and histologic examination. / Master of Science
42

Can isoprostanes be used to predict survival in horses with colic?

Noschka, Erik 08 December 2010 (has links)
Approximately 4% of horses suffer from one colic episode per year. The outcome is fatal in 11% of cases. F2-isoprostanes are the "gold standard" for assessment of oxidative stress in vivo and have been used extensively to quantify lipid peroxidation in association with risk factors in various diseases in humans. Because horses with colic may have intestinal ischemia and/or inflammation characterized by oxidative stress and increased production of isoprostanes, measurement of isoprostane concentrations in colicky horses may be of clinical value. The purpose of this study was to gather preliminary data on the feasibility of using urine isoprostane concentrations as an early screening tool for the severity of colic and to determine the need for surgery. The long term goal of this investigation is to reduce the number of deaths due to colic by developing a stall-side test capable of identifying horses needing surgery as early as possible and expediting their timely referral. We hypothesized that urine isoprostanes and isoprostane metabolites would be significantly higher in horses with colic compared to normal horses and that they can be used an indicator for the need for surgical intervention. Urine samples were collected from 42 normal horses and 38 horses with colic (21 medical and 22 surgical). Urine isoprostane and isoprostane metabolite concentrations were measured by mass spectrometry and normalized by urine creatinine (Cr) concentrations. Statistical analysis was performed using a one way ANOVA (Tukey's post-hoc comparison) and a 2 sample t-test. Significance was set at P<0.05. Mean (± SD) concentrations of isoprostanes and isoprostane metabolites were significantly higher in urine samples of horses with colic (2.94 ± 1.69 ng/mg Cr and 0.31 ± 0.22 ng/mg Cr, respectively) compared to healthy horses (1.89 ± 1.39 ng/mg Cr and 0.22 ± 0.08 ng/mg Cr, respectively). Urine isoprostane metabolite concentrations were significantly higher in horses undergoing surgery (0.38 ± 0.28 ng/mg Cr) compared to healthy control horses and medically treated colic horses (0.26 ± 0.11 ng/mg Cr). Non-survivors had significantly higher mean urine isoprostane metabolite concentrations (0.47 ± 0.39 ng/mg Cr) compared to healthy control horses and surviving colic horses (0.29 ± 0.24 ng/mg Cr). Since urinary concentrations of isoprostane metabolites are increased in horses suffering from colic and in non-survivor colic horses, the measurement of urine concentrations of isoprostane metabolites may be an important prognostic indicator in equine colic. / Master of Science
43

Effects of Supplementing Ponies with Dietary Fat on Nutrient Digestibility and Blood Insulin, Glucose, and Fatty Acid Concentrations

Bova, Toree Lee 14 August 2015 (has links)
Fat supplementation is a common practice to increase caloric intake in the performance horse. The effects of fat on fiber digestibility is unknown. Understanding of digestibility in the equine digestive tract is limited by sampling technique. While cecal and ileal cannulations have previously been utilized to determine equine nutrient digestibility and gastrointestinal physiology, the current research has been limited to singular portions of the equine digestive tract. The objectives of this dissertation were to determine the effects of dietary fat supplementation on nutrient digestibility and blood insulin, glucose, and fatty acid concentrations using dual cannulated ponies. The first step to this objective was establishment of a dual cannulated pony herd for research. This study resulted in a post-operation survival rate of 63%. Five of the dual cannulated ponies were fed hay and pelleted alfalfa and supplemented with vegetable oil at 0, 5, 10, or 15 % of total diet. Ileal, cecal, fecal, and blood samples were taken with blood samples analyzed for glucose, insulin and fatty acids. There was a treatment by time effect (P < 0.1) for apparent ileal and cecal fat digestibility and apparent cecal digestibility of crude protein. Apparent total tract digestibility of NDF, ADF and fat was affected by time (P < 0.1). Adding fat increased (P < 0.1) apparent total tract digestibility of fat. At 0 h post feeding apparent total tract digestibility of protein was greatest (P < 0.1) compared to other time periods. Plasma concentration of insulin increased (P < 0.1) over time. Ponies consuming 0 % fat diet had increased C14:0 compared to 5, 10, and 15 % diet. Adding fat at 5, 10, and 15 % of the diet increased C18:2 n-6 when the ponies were fed 0 % fat. Further research using a dual cannulated equine research herd is needed to more completely understand digestibility of other components of the equine diet.
44

Effect of acupuncture on heart rate variability at rest and on stride length and frequency at gallop in thoroughbred racehorses

Hartwigsen, Roselle 08 1900 (has links)
The aim of this study was to determine whether three acupuncture treatments affected thoroughbred racehorses in training. Heart rate variability (HRV) at rest and stride parameters (SP) during a 600m gallop were measured. Needles were inserted for 20 minutes into pre-selected acupuncture points in the treatment horses while those in the non-treatment group were haltered. The delta values (post-treatment minus pre-treatment) of the groups were compared. There were no significant changes (p < 0.05) in the HRV indicators. The treatment group showed (delta median of treatment vs. non-treatment group) that the parasympathetic (PNS) indicators shifted towards inhibition of the vagal system (RMSSD = - 2.19 vs. 1.47; HF = - 37.19 vs. 19.42; SD1 = - 1.56 vs. 1.04). The delta medians of indicators associated with the combined effect of the PNS and sympathetic nervous system (SDNN = 4.39 vs. - 4.00; LF = 179.48 vs. - 397.26; SD2 = 8.55 vs. - 7.48); cardiac autonomic balance (LF/HF = 0.26 vs. - 0.32; LF norm = 14.23 vs. - 0.80; HF norm = - 4.78 vs. 3.54) and heart rate measures (Mean HR = 3.96 vs. - 3.00; Mean RR = - 169.72 vs. 107.54) showed a shift in opposite directions. The SP results showed a significant increase in maximum stride count (p = 0.004). The delta medians showed a shift in opposite directions i.e., average stride length (-0.06 vs. 0.05), average stride count (0.31 vs. -0.26), maximum stride count (0.84 vs. -5.70), maximum speed (1.30 vs. -0.80) and stride length at maximum speed (0.13 vs. -0.01). Thus, the non-treatment group seemed to perform better and were calmer, suggesting that a withdrawal period may be appropriate following acupuncture treatments. / Dissertation (MSc (Veterinary Sciences))--University of Pretoria, 2021. / AgriSETA bursary / Companion Animal Clinical Studies / MSc (Veterinary Sciences) / Unrestricted
45

Epidemiologic and Economic Study of Hyperelastosis Cutis/HERDA in the Quarter Horse Cutting Industry

Tipton, Sally Grant 13 December 2008 (has links)
Hyperelastosis Cutis (HC) is an autosomal recessive disorder in Quarter Horses. Homozygous (Hr/Hr) horses are affected with fragile, hyperextensible skin that sloughs and scars easily following minor trauma. Heterozygous (N/Hr) horses appear normal, but carry one copy of the gene. Objectives were to determine inbreeding coefficients of affected (Hr/Hr), carrier (N/Hr), and normal (N/N) Quarter Horses, compared to Thoroughbreds, and evaluate economic effects of HC within the cutting horse industry. Of the top cutting horses from 1985 through 2006, 35 were confirmed carriers by either DNA analysis or production of affected offspring. Although 23% of the earnings from the leading 100 lifetime earning sires ($388 million) were attributed to 12 carrier sires, average offspring earnings of carrier sires were not significantly different from normal sires. The increase in dollars is due to the number of earning offspring produced by carriers, highlighting the need for DNA testing and appropriate breeding selections.
46

An Exploratory Mixed Methodology Study Into the Theoretical Foundation of Equine-Assisted Psychotherapy

Dawson, Bradford Tyler 01 June 2014 (has links)
Equine-assisted psychotherapy is emerging as a new alternative therapy method. As the field is new, there is limited amount of research looking at the current theoretical foundation being utilized in the therapeutic process. This study aims to explore the field of equine-assisted psychotherapy and its current theoretical foundation. The main question guiding this study was: What are the therapeutic theories and themes guiding the current practice of equine-assisted psychotherapy? The study consisted of six in-person qualitative interviews with current practitioners of equine-assisted psychotherapy. A short Likert-type scale was also used to quantitatively gather descriptive statistics about theories currently being used by these practitioners. The results of this study yielded interesting findings about the similarities between equine-assisted psychotherapy and traditional office therapy. The use of horses in therapy creates new dynamics to be addressed in the therapeutic process. The practitioners interviewed in this study agreed on many different aspects about the application of equine-assisted psychotherapy to clients displaying characteristics of trauma, anxiety, depression, and boundary issues, but also had dissenting opinions about other aspects of the practice. The generalist model of social work practice is utilized in the questionnaire. This method of questioning found that the use of the generalist model is applicable to the field of equine-assisted psychotherapy.
47

Equine assisted activities or therapy : towards a future curriculum

Shkedi, Anita January 2015 (has links)
Equine Assisted Activities and Therapy (EAA/T) is a non-invasive treatment modality recommended by the medical and educational community for a subset of challenged children and adults. As its popularity increases, so too are the concerns among stakeholders and the medical and educational professions about its legitimacy as a treatment modality. The main concern being that EAA/T practitioners have not acquired the professional skills required and that the EAA/T treatment programmes are not evidence-based. The central question of this research focused on identifying Equine Assisted Activities and or Therapy (EAA/T) and creating an optimal learning curricula and more practical experience for future practitioners. In order to explore these issues an extensive multi-method research study was conducted to identify gaps in EAA/T curricula, which included a review of empirical data and different curriculum models. The Delphi Method (DM), a robust, qualitative, naturalistic, systematic and interactive research method was used to support the research. Part of the DM required an analysis of data, adaptation of issues and amendments to questions culminating in a collective consensus among EAA/T experts. The key research findings suggested that current training programmes use curricula with significant gaps resulting in poor professional knowledge formation, a lack of experiential learning, insufficient knowledge of equestrianism and an inability to use pedagogic paradigms. Other findings showed that curricula being used were not being built as an application of sound theoretical principles but rather, transmitted in a manner that does not motivate active and meaningful learning or promote the best practical experience. As a consequence, national organisations and academies dedicated to EAA/T training sidestep high standards and core values for the sake of membership and financial gain. This rigorous research study has highlighted gaps in current training practices and has made it possible to make recommendations for a future curriculum. Recommendations that suggest the future curriculum is built on sound theoretical principles developing foundation knowledge to operate EAA/T in all fields of practice. This could set new quality and performance benchmarks and provides EAA/T practitioners with adequate tools to connect best practices to people with real-life challenges.
48

Equine-assisted psychotherapy as an effective therapy in comparison to or in conjunction with traditional therapies

Wilson, Kristen 01 December 2012 (has links)
Mental disorders are a prevalent health issue that has an extensive amount of variability in the quantity of disorders, affected populations, and treatment. There are a multitude of approaches or therapeutic methods used by the mental health community. Although each therapy is valuable in unique ways, each therapy may not be suitable to treat every disorder or client. Traditional approaches, such as talk therapy, are effective for certain individuals, whereas some clients may not respond well to any of the traditional talk therapies. When traditional therapies are not working, a referral can be made for a therapy that might suit the client better. Equine-Assisted Psychotherapy (EAP) is an experiential psychotherapy that has done well not only in assisting typical clients, but also with clients that have had trouble in traditional modes of therapy. This is a collaboration of current works and research in EAP, along with the knowledge base of a current licensed practitioner of EAP. The purpose is to lay out the fundamentals of EAP, which offers a different modality than traditional talk therapies. By crafting a better picture of EAP, perhaps it can kindle further research in its efficacy and guide additional mental health professionals towards this type of therapy.
49

Equine laminitis pain and modulatory mechanisms at a potential analgesic target, the TRPM8 ion channel

Viñuela-Fernández, Ignacio January 2011 (has links)
Chronic neuropathic pain, resulting from dysfunction of the nervous system, is a clinical concern in both humans and animal patients. Neuropathic pain is characterised by spontaneous pain, hypersensitivity, manifested as hyperalgesia and allodynia, and refractoriness to conventional analgesics such as non-steroidal anti-inflammatory drugs, thus representing an unmet therapeutic need. Equine laminitis is a disease that involves the disruption of the dermoepidermal junction within the hoof, leading to severe pain and lameness, with poor responsiveness to anti-inflammatory therapy. We developed a Quantitative Sensory Testing method, using a novel hydraulically-powered feedbackcontrolled hoof tester, in order to provide an objective tool for the assessment of mechanical hyperalgesia in laminitic horses. Hoof Compression Thresholds of laminitic horses were significantly lower than those of normal horses and variance component analysis of the data confirmed the reliability of the method. In order to investigate mechanisms underlying laminitis pain, we performed histological studies of peripheral nerves innervating the hoof. Electron micrographic analysis of the digital nerve of laminitic horses revealed a significant reduction in the number of unmyelinated and myelinated fibres together with abnormal morphology. Additionally, cell bodies of sensory neurons innervating the hoof in cervical C8 dorsal root ganglia showed an upregulated expression of the nerve injury marker activating transcription factor-3 (ATF3), neuropeptide Y (NPY), and the TRPM8 channel; each of which has been associated with laboratory models of neuropathic pain. Previous work has shown that, in a rodent model of neuropathic pain, the TRPM8 channel is upregulated in sensory neurons and its activation by cool temperature, menthol or icilin leads to reversal of the hypersensitive pain state. Further investigation of TRPM8-channel mediated analgesia was aimed at uncovering the molecular mechanisms involved in the activation of this system in sensitised states. It was hypothesised that serotonin, released following inflammation and nerve damage, can enhance TRPM8 channel activity through peripheral 5-HT1B receptors. Calcium fluorometry carried out in HEK293 cells transfected with the TRPM8 channel and the 5-HT1B receptor revealed that coadministration of a 5-HT1B receptor agonist facilitated the activation of the TRPM8 channel by icilin. Moreover, it appears that this effect is mediated through phospholipase D1 (PLD1), possibly leading to increased production of phosphatidylinositol (4,5-) bisphosphate (PIP2), a known positive modulator of TRPM8 channel activity. In vitro co-immunoprecipitation studies suggested that the TRPM8 channel, the 5-HT1B receptor and PLD1 physically interact with each other, further providing a molecular basis for their functional co-operation. Calcium imaging carried out in cultured rat DRG cells showed that the 5-HT1B receptor-mediated enhancement of icilin responses at the TRPM8 channel also occurs in sensory cells and is reversed by inhibition of PLD1. Moreover, TRPM8 and the 5-HT1B receptor appear to be physically associated in vivo as shown by their co-immunoprecipitation from spinal cord homogenates. Assessment of nociceptive behavioural reflexes following intrathecal injection of selective pharmacological agents provided further support for the idea of 5-HT1B receptor facilitation of TRPM8 channel responses in vivo. In addition to providing novel evidence of a neuropathic component to equine laminitis and validation of a novel QST method for pain assessment in horses, this study reveals for the first time a physical and functional interaction between the 5-HT1B receptor and the TRPM8 channel.
50

A pathological, histological and ultrastructural study of diseased equine cheek teeth

Dacre, Ian Thomas January 2004 (has links)
The examination of 220 normal and 130 diseased equine (extracted) cheek teeth was performed using a variety of traditional and novel imaging techniques primarily to assess the aetiopathogenesis of the important dental disorders of apical infection and "idiopathic" dental fracture. Optimal settings for radiography and computer axial scanning of normal and diseased cheek teeth were determined. It was found that standard radiography of extracted cheek teeth was very poor at identifying intradental anatomical or pathological features, whilst computer axial scanning gave accurate information on both normal and abnormal radiographic features. Newly established histological techniques allowed preparation of undecalcified sections of 4-6 μm thickness, and undecalcified sections of 50-60 μm thickness. The current classification of equine dentine was modified, with primary, regular secondary, irregular secondary and tertiary dentine all being categorised separately. Previously undescribed histological features of normal and diseased equine teeth were identified such as dentinal pearls, interglobular dentine, caries and the presence of pioneer micro-organisms. The normal endodontic anatomy of all 24 cheek teeth was established, with individual pulp horns being identified using a unique numbering system. Anatomical parameters of dentine were established for normal cheek teeth, and these were compared to those of apically infected cheek teeth. A decreased presence of primary and secondary dentine, predentine and intertubular dentine was found in diseased teeth compared with normal cheek teeth, but increased number of resting lines were present in diseased cheek teeth. Analysis of 50 individual apically infected cheek teeth showed anachoretic pulpitis to be the most common aetiology, with occlusal pulp exposure often being a secondary finding. Apical infection caused by periodontal disease or infundibular caries was uncommon finding. Fracture patterns to the clinical crown of equine cheek teeth were grouped, with most fractures involving the buccal pulp horns of both maxillary and mandibular cheek teeth.

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