bluuebunny/crossref_metadata_2025 huggingface dataset:
Physeal growth retardation leads to correction of intracarpal angular deviations as well as physeal valgus deformity
Authors: BRAUER T. S. , BOOTH T. S. , RIEDESEL E.
Published: April 2010

Retrospective analysis of the radiographs of horses with carpal valgus, presented to the Iowa State University Veterinary Teaching Hospital from 1987–1996, were used to compare 2 methods of geometric analysis for finding the total angle of deviation. The pivot point angle method and the individual joint angle method were found to be comparable for determining the total angle of deviation. The individual joint angle method was used to analyse individual carpal joint angles and physis angle in joints with carpal valgus, as well as the changes that occurred in response to surgical correction. Multiple joint involvement was common with carpal valgus; and surgical manipulation caused a change in angle at all joints. Use of the individual joint angle method for evaluating carpal valgus may aid the surgeon in making a more accurate prognosis.
Comparison of bacteriology and cytology of tracheal fluid samples collected by percutaneous transtracheal aspiration or via an endoscope using a plugged, guarded catheter
Authors: CHRISTLEY R. M. , HODGSON D. R. , ROSE R. J. , REID S. W. J. , HODGSON J. L.
Published: April 2010

Cytological and bacteriological results from tracheal fluid samples obtained endoscopically using a telescoping, plugged catheter (TPC) were compared with results from samples collected by percutaneous transtracheal aspiration (PTA). The TPC technique and PTA were performed in random order on 9 healthy Standardbred geldings. Three weeks later the procedures were performed on the same horses in the reverse order. The presence of oropharyngeal contamination was determined by quantitative bacteriology and quantification of squamous epithelial cells (SEC)/ml sample. The relative numbers of macrophages, haemosiderophages, giant cells, neutrophils, lymphocytes and eosinophils did not differ between techniques. The number of SEC/ml was greater in samples with more colony forming units/ml indicating that quantification of SEC provides evidence of the probable degree of oropharyngeal contamination. Fifteen out of the 18 TPC samples were free of contamination, indicating that the TPC can provide adequate samples for bacteriology. The results also indicate that tracheoscopy sometimes results in oropharyngeal contamination of the trachea, but that this does not affect the results of the TPC sample.
Physiological responses of horses to a treadmill simulated speed and endurance test in high heat and humidity before and after humid heat acclimation
Authors: MARLIN D. J. , SCOTT CAROLINE M. , SCHROTER R. C. , HARRIS R. C. , HARRIS PATRICIA A. , ROBERTS C. A. , MILLS P. C.
Published: April 2010

To investigate whether horses were able to acclimate to conditions of high temperature and humidity, 5 horses of different breeds were trained for 80 min on 15 consecutive days on a treadmill at 30°C and 80% RH. Training consisted of a combination of long duration low‐intensity exercise, medium duration medium intensity exercise and short duration high intensity exercise. Between training sessions the horses were maintained at 11 ± 3°C and 74 ± 2% RH. Before (PRE‐ACC) and after acclimation (POST‐ACC) the horses undertook a simulated Competition Exercise Test (CET), designed to represent the Speed and Endurance Test of a 3‐day event, at 30°C/80% RH.

Maximal oxygen uptake (VO2PEAK) was not changed following acclimation (PRE‐ACC 141 ± 8 ml/min/kg bwt vs. POST‐ACC 145 ± 9 ml/min/kg bwt [STPD], P>0.05). Following acclimation, 4 of the 5 horses were able to complete a significantly greater amount ofPhase Din the CET (PRE‐ACC 6.3 ± 0.3 min vs. POST‐ACC 7.3 ± 0.3 min, P<0.05; target time = 8 min).

Resting body temperatures (pulmonary artery [TPA], rectal [TREC] and tail‐skin [TTSK] temperatures) were all significantly lower following acclimation. During exercise, metabolic heat production (M) and heat dissipation (HD), for the same exercise duration, were both significantly lower following acclimation (P<0.05), although heat storage (HS) was significantly higher (P<0.05). The higher heat storage following acclimation was associated with a lower TTSKfor a given TPAand a decreased total fluid loss (% bodyweight, P<0.05). Plasma volume was not changed following acclimation. The relationship of sweating rate (SR) to TPAor TTSKon either the neck or the gluteal region was not significantly altered by acclimation, although the onset of sweating occurred at a lower TPAor TTSKfollowing acclimation (P<0.05).

The horses in the present study showed a number of physiological adaptations to a period of 15 days of exposure to high heat and humidity consistent with a humid heat acclimation response. These changes were mostly similar to those reported to occur in man and other species and were consistent with thermal acclimation and an increased thermotolerance, leading to an improved exercise tolerance. It is concluded that a 15 day period of acclimation is beneficial for horses from cooler and or drier climates, that have to compete in hot humid conditions and that this may redress, to some extent, the decrement in exercise tolerance seen in nonacclimated horses and reduce the risk of heat related disorders, such as heat exhaustion.
A field survey on the distribution of strongyle infections of horses in Sweden and factors affecting faecal egg counts
Authors: LIND E. OSTERMAN , HÖGLUND J. , LJUNGSTRÖM B.‐L. , NILSSON O. , UGGLA A.
Published: April 2010

Faecal egg counts were performed during the first quarter of 1995 on samples from 1183 horses of varying breeds, ages and gender on 110 farms in 3 regions of Sweden. The majority of the horses had been treated with ivermectin or pyrantel when stabled the previous autumn. The risk of reinfection with strongyles between treatment and sampling was therefore considered to be minimal. Consequently, the results reflect primarily the occurrence of worms originating from inhibited strongyle larvae refractory to anthelmintic treatment. A total of 922 (78%) individuals were found to shed strongyle eggs, and 15 (14%) of the farms studied had at least one horse infected withStrongylus vulgaris.There was a significant, gradual decrease in faecal egg output in horses originating from the southern to the northern part of Sweden. Horses from studfarms showed significantly higher numbers of strongyle eggs/g faeces (EPG) as compared to those on other types of farms, such as riding‐schools and boarding stables. However, there was no correlation between herd size and mean herd EPG. The output of strongyle eggs was highest in horses aged 2 and 3 years. EPG values then declined with increasing age of the horse. Horses treated with ivermectin in the previous autumn showed significantly lower EPG values than untreated horses and those treated with pyrantel pamoate.
Naturally occurring osteoarthritis in the metacarpophalangeal joints of wild horses
Authors: CANTLEY CHARLOTTE E. L. , FIRTH E. C. , DELAHUNT J. W. , PFEIFFER D. U. , THOMPSON K. G.
Published: April 2010

This study identified changes consistent with osteoarthritis; articular cartilage damage, subchondral bone sclerosis and marginal osteophytes, in the metacarpophalangeal joints of wild New Zealand horses. The articular cartilage lesions were identified by Indian ink staining techniques and histology. The lesions occurred on the proximodorsal aspect of the first phalanx (P1) and were more severe on the medial compared to the lateral eminence of the bone, and their severity increased with age. The bone mineral density of the subchondral bone underlying the cartilage lesions, assessed using conventional radiography and dual energy absorptiometry, also increased with age and with severity of the overlying cartilage lesion. Subjective assessment of cabinet radiographs revealed that the subchondral bone sclerosis was greater in horses with severe articular cartilage damage. Ossicles, with a distinct trabecular bone pattern, were identified at the proximo‐dorsal margin of P1 in 8 specimens from 5 horses from the older age groups (greater than age 5 years).

The results of this study demonstrate age‐related changes consistent with osteoarthritis in the metacarpophalangeal joints of wild horses. There appears to be a significant relationship between subchondral bone sclerosis and overlying cartilage degeneration in the proximodorsal aspect of P1. We have identified an age‐related osteoarthritic process naturally present in horses; and postulate that the stresses of racing and training may accelerate this ageing process.
Aetiopathogenesis of parasagittal fractures of the distal condyles of the third metacarpal and third metatarsal bones ‐ review of the literature
Authors: RIGGS C. M.
Published: April 2010

Fractures are the cause of considerable morbidity and mortality among Thoroughbred racehorses. A significant proportion of these injuries occur in the absence of any particular traumatic incident. Evidence of prefracture pathology interpreted as fatigue damage has been identified in some such cases, but the aetiology of many of these so‐called ‘spontaneous’ fractures remains obscure. Parasagittal fractures of the third metacarpal (McIII) and third metatarsal (MtIII) bones are one of the more common fractures to affect Thoroughbred racehorses. The configuration of each of these fracture types is highly consistent, suggesting a predisposition of the bones to these injuries. Several theories have been proposed to explain the aetiopathogenesis of these fractures although none has so far stood up to critical examination. The current paper reviews the literature relating to parasagittal fractures of McIII and MtIII.
Three dimensional structure of the distal condyles of the third metacarpal bone of the horse
Authors: BOYDE A. , HAROON Y. , JONES S. J. , RIGGS C. M.
Published: April 2010

This study examined the three‐dimensional (3D) microarchitecture of regions of the equine third metacarpal bone (McIII) commonly involved in distal condylar fractures. Limbs were obtained from Thoroughbred horses (neonates to age 24 years) destroyed for inoperable fractures and a variety of other conditions. Beams, blocks and sections were cut in the principal axes, some embedded in PMMA and others examined unembedded. Several methods were used to study the 3D structure, including conventional and confocal optical microscopy, scanning electron microscopy (SEM) and radiography. The mineralised articular cartilage tends to cleave in the sagittal plane. Proximal to the subchondral bone, the main trabeculae are robust plates running in the sagittal direction with less significant mediolateral connections. Small blood vessel canals lie inside the sagittal plates. This structure gives maximum strength and protection in the sagittal plane in which the bone rotates, but offers minimal resistance to fracture propagation in this plane. The anatomical course of the common distal condylar fractures of the third metacarpal bones can be explained by underlying anisotropic structural features of the mineralised tissues.
PGFM response to exogenous oxytocin and determination of the half‐life of oxytocin in nonpregnant mares
Authors: PACCAMONTI D. L. , PYCOCK J. F. , TAVERNE M. A. M. , BEVERS M. , VAN DER WEIJDEN G. C. , GUTJAHR S. , SCHAMS D. , BLOUIN D.
Published: April 2010

We investigated the half‐life of oxytocin in reproductively normal mares and the prostaglandin response after oxytocin administrations. Mares were given oxytocin, 10 or 25 iu, i.v., on the day of, or 2 days after, ovulation, and frequent jugular blood samples were collected for analysis of oxytocin and Prostaglandin F metabolite (PGFM) by RIA. Neither dose of oxytocin nor day of treatment affected the half‐life of the exogenous oxytocin, which was determined to be 6.8 min. A significant increase in PGFM was observed within 6 min of oxytocin administration and peak values were observed within 10 min. PGFM response after oxytocin administration on the day of ovulation appeared elevated compared to the response 2 days after ovulation.
Indices of oxidative stress in blood and pulmonary epithelium lining fluid in horses suffering from recurrent airway obstruction
Authors: ART TATIANA , KIRSCHVINK NATHALIE , SMITH NICOLA , LEKEUX P.
Published: April 2010

To test the hypothesis that reactive oxygen species could be associated to the lower airway disorders occurring in horses suffering from recurrent airway obstruction (RAO), indices of oxidative stress were studied in blood and pulmonary epithelium lining fluid in 5 RAO horses either in clinical remission or 24 h after the onset of a crisis of bronchospasm and in 5 healthy horses. Venous blood and bronchoalveolar lavage fluid (BALF) samples were collected and analysed for reduced glutathione (GSH), oxidised glutathione (GSSG), total glutathione (TGSH), glutathione redox ratio (GRR) in blood haemolysate and pulmonary epithelium lining fluid (PELF). The haemolysate concentrations of GSH, GSSG, TGSH and GRR were similar in the 3 groups. The PELF glutathione status was significantly different in the RAO horses in acute crisis compared to healthy horses, indicating the occurrence of an oxidative stress. When RAO horses were in crisis their GSH and TGSH remained unchanged but their GSSG and GRR were significantly increased compared to the remission.

These results support the hypothesis that oxidative stress is associated with lower airway disorders occurring in horses suffering from RAO.
Radiological measurements from the feet of normal horses with relevance to laminitis
Authors: CRIPPS P. J. , EUSTACE R. A.
Published: April 2010

Lateromedial radiographic projections were made from the feet of 25 normal horses and 3 angles and 3 distances were measured. From these, normal ranges of calculated variables were obtained. The width and length of each foot and the height of the horse at the withers was also measured. In view of its possible importance in clinical laminitis, particular attention was paid to ‘founder’ distance (D). This is the vertical distance between the proximal limit of the dorsal hoof wall and the proximal limit of the extensor process of the distal phalanx. There were significant differences between breeds inD(P<0.05) and in wall thickness (P<0.01). Further studies investigated the effects of time, differing radiographic projections and different operators onD. Ddid not alter significantly (P>0.05) over a 6 week study period. It was concluded that errors due to radiographic beam obliquity were not of practical importance. Errors in measuringDbetween operators can be minimised by use of a standard radiographic technique. Although there was some variation in the value ofDmeasured over time and with different operators, which could make the interpretation of early or subtle changes difficult, measurement variation was not considered to interfere with the assessment of large changes associated with severe laminitis.
Encephalopathy with idiopathic hyperammonaemia and Alzheimer type II astrocytes inEquidae
Authors: HASEL KRISTIN M. , SUMMERS B. A. , DE LAHUNTA A.
Published: April 2010

In 3 mature female horses of varying breeds, episodes of colic and depression for 1–4 days preceded an encephalopathic disorder with maniacal behaviour, anxiety, profuse sweating and, in one case, terminal opisthotonus. Blood ammonia levels were elevated approximately 10‐fold. At necropsy, there were gastrointestinal serosal and mesenteric haemorrhages. Histologically, all 3 cases revealed diffuse Alzheimer type II astrocytes in the cerebral grey matter. Alzheimer type II astrocytes were glial fibrillary acidic protein (GFAP) negative or only weakly positive, weakly S‐100 positive, and vimentin negative. In the absence of primary hepatic and/or renal lesions, an increase in intestinal ammonia absorption due to ileus or increased ammonia production by colonic bacteria is hypothesised.
Transabdominal ultrasonographic determination of fetal gender in the horse during mid‐gestation
Authors: RENAUDIN CATHERINE D. , GILLIS CAROL L. , TARANTAL ALICE F.
Published: April 2010

Gender determination of the equine fetus using transabdominal ultrasonography was studied in 20 mares. One group of 10 research mares was scanned repeatedly every 2 weeks from 100 days gestation to parturition, while the second group of 10 client mares was subjected to echography once during mid‐gestation. In males, the penis and/or prepuce was observed on 71 occasions from 102 days to 258 days gestation. On cross‐sectional views, the male external genitalia had a round shape with parallel linear echogenic foci up to approximately 140 days gestation and then appeared triangular. Fetal testes were oval in shape in frontal view and had an homogeneous ultrasonographic appearance. Females were diagnosed on 23 occasions from 118 days to 227 days gestation based on the presence of the mammary glands and teats. Fetal ovaries appeared homogeneous with a characteristic circular echo from 100 days to 134 days gestation.

Gender identifications (n = 98) based on the presence of the penis and/or prepuce in males and mammary glands and teats or fetal gonads in females were all correct, in agreement with the sex of the foals at birth. The optimal window of time was defined in both sexes as 100 to 220 days gestation. Thereafter, it was increasingly difficult to identify the anatomical structures cited above. Fetal sex was mainly determined using the transabdominal approach (87/98). However, the transrectal approach was useful in cases in which fetuses were either in posterior presentation or located very high in the mares abdomen. Good quality diagnostic scanners used typically in equine reproduction and equipped with a 5.0 MHz probe can be used for this procedure up to 160 days gestation, after which a 3.5 MHz transducer is often necessary due to increasing fetal size.
A new isolate of the nematophagous fungusDuddingtonia flagransas biological control agent against free‐living larvae of horse strongyles
Authors: FERNÁNDEZ A. SILVINA , HENNINGSEN E. , LARSEN M. , NANSEN R. , GRØNVOLD J. , SØNDERGAARD J.
Published: April 2010

An experiment was carried out in 1997 to test the efficacy of an isolate of the microfungusDuddingtonia flagransagainst free‐living stages of horse strongyles under conditions in the field and to assess the eventual effect of the fungus on the normal degradation of faeces. Faecal pats were made from faeces of a naturally strongyle infected horse, which had been fed fungal material at a dose level of 106fungal unit/kg bwt. Control pats without fungi were made from faeces collected from the same animal just before being fed fungi. Faecal cultures set up for both groups of faeces to monitor the activity of the fungus under laboratory conditions showed that the fungus significantly reduced the number of infective third‐stage larvae (L3) by an average of 98.4%. Five faecal pats from each batch of faeces were deposited on pasture plots at 3 times during spring‐summer. The herbage around each pat was sampled fortnightly to recover L3transmitted from faeces. The results showed that the herbage infectivity around fungus‐treated pats was reduced by 85.8–99.4%. The remaining faecal material at the end of each sampling period was collected, and the surviving L3were extracted. Significantly fewer larvae were recovered from the fungus‐treated pats. Analysis of wet and dry weight of the collected pats, as well as their organic matter content, were performed to compare the degradation of faeces of both groups. The results indicated that the presence of the fungus did not alter the degradation of the faeces.
The association ofClostridium botulinumtype C with equine grass sickness: a toxicoinfection?
Authors: HUNTER L. C. , MILLER J. K. , POXTON I. R.
Published: April 2010

The cause of grass sickness, an equine dysautonomia, is unknown. The disease usually results in death. Gastrointestinal (GI) dysfunction is a common clinical manifestation in all forms of the disease. It is generally thought that equine grass sickness (EGS) is caused by an ingested or enterically produced neurotoxin which is absorbed through the GI tract.Clostridium botulinumwas first implicated as a causative agent when it was isolated from the GI tract of a horse with EGS in 1919. The aim of the present study was to investigate the hypothesis that EGS results from toxicoinfection withC. botulinumtype C: growth of the bacterium in the GI tract with production of toxin (BoNT/C). Ileum contents and faeces from horses with EGS were investigated for BoNT/C, and indirectly for the presence ofC. botulinumtype C., and compared with control samples from horses without EGS. BoNT/C was detected directly by ELISA in the ileum of 45% (13/29) of horses with EGS compared to 4% (1/28) of controls, and in the faeces of 44% (20/45) of horses with EGS compared to 4% (3/77) of controls. Levels of up to 10 μg toxin/g wet weight of gut contents were observed. The one control horse with detectable toxin in the ileum had been clinically diagnosed as having acute EGS, but this was not confirmed by histopathology. The organism was detected indirectly by assaying for BoNT/C by ELISA after enrichment in culture medium.C. botulinumtype C was shown to be present in 48% (14/29) of ileum samples and 44% (20/45) of faecal samples from horses with EGS, compared with 7% (2/27) of ileum samples and 8% (6/72) of faecal samples from controls. These results support the hypothesis that EGS results from aC. botulinumtype C toxicoinfection.
Retrospective study of subchondral sclerosis and lucency in the third carpal bone of Standardbred trotters
Authors: UHLHORN H. , CARLSTEN J.
Published: April 2010

The aim was to investigate radiographic findings of subchondral sclerosis and subchondral lucency in the dorsoproximal‐dorsodistal (DPr‐DDi) projection of the third carpal bone (C3) in relation to clinical appearance and to prognosis for racing. In a retrospective study, case records of 89 Standardbred trotters diagnosed with traumatic carpitis confirmed with intra‐articular anaesthesia were examined. Records included data on degree of lameness at presentation and after flexion tests and a radiographic examination of the carpus, including a DPr‐DDi projection of the C3. Subchondral lucency was found significantly to influence the degree of lameness at presentation and the time to start but did not significantly affect the chance of racing within 30 months post examination. In the present material no significant relationship between degree of sclerosis and lameness or prognosis for racing within 30 months was found, but the low number of C3 with severe sclerosis limited conclusions about that group.
MMP‐9 as a marker of inflammation in tracheal epithelial lining fluid (TELF) and in bronchoalveolar fluid (BALF) of COPD horses
Authors: RAULO S. M. , SORSA T. , TERVAHARTIALA T. , PIRILÄ E. , MAISI P.
Published: April 2010

Gelatinolytic activity was analysed to study whether elevated activity previously found at the tracheal level of the respiratory tract of horses with chronic obstructive pulmonary disease (COPD) could also be found at the lower part of the respiratory tract. Furthermore, presence and significance of the gelatinolytic matrix metalloproteinases (MMPs) MMP‐2 and MMP‐9 in respiratory secretions of healthy and COPD horses were determined. Elevated gelatinolytic matrix metalloproteinases were detected in bronchoalveolar and tracheobronchial secretions from COPD horses. The main pathologically elevated MMP was characterised to be MMP‐9. Significantly increased MMP‐9 activities as measured by gelatin zymography and Western blotting were found in all the respiratory samples from COPD horses compared to healthy horses. Elevation of active MMP‐9 paralleled with increased gelatinase‐associated lipocalin levels. Bronchoalveolar lavage fluid (BALF) epithelial cells, macrophages, neutrophils and lymphocytes expressed MMP‐9 immunoreactivity demonstrated by immunocytochemistry and MMP‐9 mRNA was expressed by bronchial epithelial cells of lung tissue section shown byin situhybridisation. MMP‐2 seems not to play a major role in chronic lung inflammation. No clear differences in MMP‐2 or MMP‐14 (a potent MMP‐2 activator) levels were found when comparing the samples from COPD or healthy horses. These results suggests that MMP‐9 could serve as a potential diagnostic marker for the active ongoing tissue remodelling in the acute phase of equine COPD. Increased gelatinolytic activity could be found at both tested respiratory tract levels. Therefore, tracheal epithelial lining fluid (TELF) samples can usefully serve as diagnostic material for detection of increased levels of the main gelatinolytic MMP, MMP‐9, representing the entire diseased lung.
Morphology of the nerve endings in laryngeal mucosa of the horse
Authors: YAMAMOTO Y. , ATOJI Y. , HOBO S. , YOSHIHARA T. , SUZUKI Y.
Published: April 2010

To discuss the significance of laryngeal sensation on various disorders of the horse, we studied the morphological and topographical characteristics of sensory structures in the laryngeal mucosa using immunohistochemistry and immunoelectron microscopy. Various sensory structures, i.e. glomerular endings, taste buds and intraepithelial free nerve endings, were found in the laryngeal mucosa by immunohistochemistry for protein gene product 9.5 (PGP 9.5) and neurofilament 200kD (NF200). Glomerular nerve endings were distributed mainly in the epiglottic mucosa; some endings were also found in the arytenoid region arising from thick nerve fibres running through the subepithelial connective tissue. Some terminals directly contacted the epithelial cells. Taste buds were distributed in the epithelium of the epiglottis and aryepiglottic fold. In the whole mount preparation, the taste buds were supplied by the terminal branching of the thick nerve fibres. In some cases, the taste buds were arranged around the opening of the duct of the epiglottic glands. The intraepithelial free nerve endings were found to be immunoreactive for substance P (SP) and calcitonin gene‐related peptide (CGRP). These nerve endings were surrounded by the polygonal stratified epithelial cells in the supraglottic region, and by the ciliated cells in the subglottic region. The density of the intraepithelial free nerve endings was highest in the corniculate process of the arytenoid region and lowest in the vocal cord mucosa. The densities of CGRP‐ and SP‐immunoreactive nerve endings in the arytenoid region were (mean ± s.d.) 30.6 ± 12.0 and 10.0 ± 4.9 per unit epithelial length (1 mm), respectively and in the vocal fold mucosa, 1.1 ± 0.9 and 0.8 ± 0.7, respectively. Approximately one half of the CGRP immunoreactive nerve endings were immunoreactive for SP, and most SP‐immunoreactive nerve endings were also immunoreactive for CGRP. Well‐developed subepithelial plexus with numerous intraepithelial fibres were observed in flat or round mucosal projections that existed on the corniculate process of the arytenoid region. In conclusion, the laryngeal mucosa of the horse seems to have morphology‐ and/or location‐dependent sensory mechanisms against various endo‐and exogenious stimuli.
The force and contact stress on the navicular bone during trot locomotion in sound horses and horses with navicular disease
Authors: WILSON A. M. , McGUIGAN M. P. , FOURACRE L. , MacMAHON L.
Published: April 2010

Mechanical overload due to poor conformation or shoeing has been suggested to contribute to the development of navicular disease. While studies have determined the compressive force exerted on the navicular bone in normal horses, this has not been reported for horses with navicular disease. Also, the force has not been converted to stress by correction for contact area. In this study we developed a technique for the determination of the contact area between the deep digital flexor tendon and the navicular bonein vivo, and used a forceplate system to determine the force and stress on the bone at trot in 6 normal and eight diseased horses. The mean ± s.d. peak force and peak stress were 5.62 ± 1.45 N/kg and 2.74 ± 0.76 MPa for the normal group and 6.97 ± 1.50 N/kg and 3.07 ± 0.55 MPa for the navicular disease group. The peak force and peak stress were similar for both groups but the force and stress in the horses with navicular disease were approximately double control group values early in the stance phase. This was due to a higher force in the deep digital flexor tendon, which was attributed to a contraction of the deep digital flexor muscle in early stance in an attempt to unload the heels.
Relationships of age and shape of the navicular bone to the development of navicular disease: a radiological study
Authors: DIK K. J. , BELT A. J. M. van den , BROEK J. van den
Published: April 2010

Estimating the shape of the proximal articular border of the navicular bone and grading the radiological navicular bone condition(grades 3and4representing the most severe changes), the aim of this study was to assess potential age‐related implications of the previously reported shape predisposition to navicular disease in 746 normal and 174 clinically affected Dutch Warmbloods age 3–19 years. A significant, age‐independent, shape‐grade association found in normal and affected horses emphasises the fundamental character of the shape predisposition to navicular disease. A significant age‐related increase of the least susceptible shape prevalence was found in elderly normal horses.

A shape‐independent lowgrades 3and4prevalence (mean 15%) was found in normal horses, vs. a highgrades 3and4prevalence (mean 85%) in the affected horses. Therefore, the clinical manifestation of the disease is grade‐rather than shape‐dependent.

A significant age‐related appearance of inverted flask‐shaped channels and enthesophytes was found in the clinically affected horses. However, considering the significant shape‐radiological features association previously reported in 3‐year‐old normal horses, this association may be shape‐ rather than age‐dependent.
Heat Transfer From Novel Target Surface Structures to a Normally Impinging, Submerged and Confined Water Jet
Authors: Jeffers Nicholas M. R. , Punch Jeff , Walsh Edmond J. , McLean Marc
Published: April 2010

Contemporary electronic systems generate high component-level heat fluxes. Impingement cooling is an effective way to induce high heat transfer coefficients in order to meet thermal constraints. The objective of this paper is to experimentally investigate the heat transfer from five novel target surface structures to a normally impinging, submerged, and confined water jet. The five target structures were: 90 deg vane, a 2×2 pin fin array, and three geometries, which turn the flow away from, and back towards, the surface to be cooled to create an annular jet. The experiments were conducted for inlet Reynolds numbers of 500≤Re≤22,000, based on the mean velocity and jet tube diameter. The confined impinging jet was geometrically constrained to a round 8.5 mm diameter, square edged nozzle at a jet exit-to-target surface spacing of H/D=0.5. The heat transfer characteristics of the five target surfaces were nondimensionally compared to a flat surface, and surface effectiveness of up to 2.2 was recorded. Enhancements of up to 45% were noted when the wetted surface area of the target surface structures was considered. The pressure drop attributed to the target surfaces is also considered. The findings of the paper are of practical relevance to the design of primary heat exchangers for high-flux thermal management applications, where the boundaries of cooling requirements continue to be tested.
A Model From First Principles of the Radial Heat Flux in a Cylinder Bore of a Modern Diesel Engine
Authors: Finol C. A. , Parker D. A. , Robinson K.
Published: April 2010

A simple model from first principles has been developed to estimate the heat transferred from the piston rings and skirt to the cylinder wall. The model considers the various forms in which heat is transferred from the combustion gases to the containing walls, namely, convection and radiation between the gases and wall surface, and conduction from piston rings and skirt through the oil film. The model also includes frictional heat generation by the rings and skirt as a result of the piston movement. Results presented in this paper show that the heat flux predicted by the model on the thrust side of the bore, at an engine speed of 4000 rpm and engine load of 100% of the limiting torque, was generally of the same order of magnitude as the heat flux estimated from experimental measurements. They also demonstrated that in the process of heat transfer from combustion gases to the cylinder wall, convection and radiation of heat have their greatest influence on the total heat flux in the top section of the cylinder bore and provide a contribution of approximately 25% over the rest of the stroke. However, the distribution of heat flux in the middle and bottom parts of the stroke shows that the main mechanism of heat transfer is conduction from the piston assembly.
Spray-Formed, Metal-Foam Heat Exchangers for High Temperature Applications
Authors: Jazi H. R. Salimi , Mostaghimi J. , Chandra S. , Pershin L. , Coyle T.
Published: April 2010

Open pore metal foams make efficient heat exchanger because of their high thermal conductivity and low permeability. This study describes a novel method of using wire-arc spraying to deposit Inconel 625 skins on the surface of sheets of 10 and 20 pores per linear inch nickel foam. The skins adhere strongly to the foam struts, giving high heat-transfer rates. Tests were done to determine the hydraulic and thermal characteristics of the heat exchangers and correlations developed to calculate Fanning friction factor and Nusselt number as a function of Reynolds number for airflow through the foam. Measured heat-transfer coefficients for the foam heat exchangers are greater than those of straight flow channels at the same flow rate. A ceramic thermal barrier coating was deposited on one face of the heat exchanger using plasma spraying. The coating and heat exchanger survived prolonged exposure to the flame of a methane-air burner.
Nanofluid Properties and Their Effects on Convective Heat Transfer in an Electronics Cooling Application
Authors: Townsend Jessica , Christianson Rebecca J.
Published: April 2010

In the search for new, more effective coolant fluids, nanoparticle suspensions have shown promise due to their enhanced thermal conductivity. However, there is a concomitant increase in the viscosity, requiring an increase in pumping power to achieve the same flow rate. Studies of flow cooling in simple geometries indicate that there is a benefit to using nanofluids, but it is difficult to justify extending these results to the far more complicated geometries. Moreover, with the variability of property measurements found in literature, it is possible to show conflicting results from the same set of flow-cooling data. In this work we present a self-contained study of the properties and effectiveness of an alumina in water nanofluid. Flow-cooling is studied in an off-the-shelf fluid cooling package for electronics to examine the effects of the particulates in a practical scenario. We measure the thermal conductivity and viscosity of the same suspensions to assure consistent interpretation of our results. We find that, while there is no anomalous enhancement of the thermal properties or transport, there is a benefit to using a low volume fraction alumina nanoparticle suspension over using the base fluid alone. In fact, there is an optimal volume fraction (1%) for this nanofluid and electronics cooling system combination that maximizes the heat dissipated. However, we find that this benefit decreases as the volume fraction, and hence the viscosity, increases. Understanding where the trade-off between viscosity increase and thermal conductivity increase occurs is critical to designing an electronics cooling system using a nanofluid as a coolant.
Concept of feedback-free high-frequency loss modulation in detuned duo-cavity vertical cavity surface-emitting laser
Authors: Yakimov M. , van Eisden J. , Tokranov V. , Varanasi M. , Oktyabrsky S. R. , Mohammed E. M. , Young I. A.
Published: April 2010

The authors propose and demonstrate a novel concept for ultrahigh-speed loss modulation of a vertical cavity surface-emitting laser (VCSEL). A duo-cavity device architecture is used to optically decouple the ac feedback component of a loss-modulation section from the VCSEL active region. The elimination of feedback allows modulation of the VCSEL output far beyond the optoelectronic relaxation frequency by eliminating both resonance and intrinsic high-frequency response roll-off. Precise detuning of the resonances of both coupled cavities is used to achieve ac feedback elimination by control of thickness during molecular beam epitaxy growth. Variation in the applied bias at the multiple-quantum-well modulator section allows adjustment of detuning to change coupling between the two sections, resulting in resonance features in the modulation response. In the ideal case, the resulting resonance-free high-frequency modulation response is limited only by parasitics of the modulator section. A flat (±3 dB) modulation response up to 20 GHz and data bandwidth up to 20 GB/s are demonstrated by using this modulation method.
Endometrial carcinoma: controversies in histopathological assessment of grade and tumour cell type
Authors: Clarke Blaise A , Gilks C Blake
Published: April 2010

Histopathological assessment of tumour grade and cell type is central to the management of endometrial carcinoma, guiding the extent of surgery and the use of adjuvant radiation therapy and chemotherapy. Endometrioid carcinomas are usually low grade but high-grade examples are encountered, and they have a significantly worse prognosis, similar to that of high-grade subtypes such as serous and clear cell carcinoma. This article reviews the various grading systems that have been proposed for use with endometrioid endometrial carcinoma, and discusses the recent progress in cell type assignment, including the use of immunohistochemistry as a diagnostic adjunct.
Avoidance Reactions of Migrating Adult Salmon to Petroleum Hydrocarbons
Authors: Weber Douglas D. , Maynard Desmond J. , Gronlund William D. , Konchin Vyacheslav
Published: April 2010

Mature Pacific salmon (Oncorhynchus sp.) migrating upstream during the peak of the run substantially avoided a mixture of monocyclic aromatic hydrocarbons in the water at concentrations of 3.2 mg/L and higher.Key words: salmon, behavior, avoidance, monocyclic aromatic hydrocarbons, Oncorhynchus
Extracellular Secondary Metabolite Production by the Marine Dinoflagellate Prorocentrum minimum in Culture
Authors: Trick Charles G. , Harrison Paul J. , Andersen Raymond J.
Published: April 2010

Marine dinoflagellates produce extracellular secondary metabolites that may play a role in the ecology of the producing species. The concentration of one such external metabolite, 1-(2,6,6-trimethyl-4-hydroxycyclohexenyl)-1, 3-butanedione, produced by the marine dinoflagellate Prorocentrum minimum, was determined quantitatively during exponential growth and during senescence in phosphate-starved batch cultures. The pattern of production is similar to the production of many bacterial toxins. There was little production of the β-diketone during the exponential growth period and highest production occurred within 1 wk after cessation of cell division. About 50% of the total β-diketone produced was excreted on a single day, 6 d after phosphate became limiting to growth. Cell lysis or photodestruction of carotenoids do not appear to be the source of this compound.Key words: antibiotic, dinoflagellate, organic excretion, Prorocentrum minimum, secondary metabolite, phosphate starvation
SHADOWS, DISCRIMINANT AND DIRECT IMAGES OF PLANE CURVE SINGULARITIES
Authors: CASAS-ALVERO EDUARDO
Published: April 2010

We prove that the images of irreducible germs of plane curves by a germ of analytic morphism φ have a certain contact either with branches of the discriminant of φ or with certain infinitesimal structures (shadows) that arise from the branches of the Jacobian of φ that are mapped to a point (and therefore give rise to no branch of the discriminant).
OPTIMIZATION OF QUANTUM MONTE CARLO WAVE FUNCTION: STEEPEST DESCENT METHOD
Authors: FOULAADVAND M. EBRAHIM , ZARENIA MOHAMMAD
Published: April 2010

We have employed the steepest descent method to optimize the variational groundstate quantum Monte Carlo wave function for He , Li , Be , B and C atoms. We have used both the direct energy minimization and the variance minimization approaches. Our calculations show that in spite of receiving insufficient attention, the steepest descent method can successfully minimize the wave function. All the derivatives of the trial wave function respect to spatial coordinates and variational parameters have been computed analytically. Our groundstate energies are in a very good agreement with those obtained with diffusion quantum Monte Carlo method (DMC) and the exact results.
A NEW HYPERCHAOTIC SYSTEM AND ITS CIRCUIT IMPLEMENTATION
Authors: LIU MINGHUA , FENG JIUCHAO , TSE CHI K.
Published: April 2010

A four-dimensional continuous-time autonomous hyperchaotic system is proposed in this letter. This system is constructed by incorporating a nonlinear control to a three-dimensional continuous-time autonomous chaotic system. The hyperchaotic system is analyzed by studying the spectrum of Lyapunov exponents and the corresponding bifurcation diagram. The system exhibits chaotic, periodic, hyperchaotic behaviors for different values of a selected control parameter. Also, a simple electronic circuit is designed and implemented. Simulations and experimental observations verify the analytical results.
Critical role of 5-HT1A, 5-HT3, and 5-HT7receptor subtypes in the initiation, generation, and propagation of the murine colonic migrating motor complex
Authors: Dickson Eamonn J. , Heredia Dante J. , Smith Terence K.
Published: April 2010

The colonic migrating motor complex (CMMC) is necessary for fecal pellet propulsion in the murine colon. We have previously shown that 5-hydroxytryptamine (5-HT) released from enterochromaffin cells activates 5-HT3receptors on the mucosal processes of myenteric Dogiel type II neurons to initiate the events underlying the CMMC. Our aims were to further investigate the roles of 5-HT1A, 5-HT3, and 5-HT7receptor subtypes in generating and propagating the CMMC using intracellular microelectrodes or tension recordings from the circular muscle (CM) in preparations with and without the mucosa. Spontaneous CMMCs were recorded from the CM in isolated murine colons but not in preparations without the mucosa. In mucosaless preparations, ondansetron (3 μM; 5-HT3antagonist) plus hexamethonium (100 μM) completely blocked spontaneous inhibitory junction potentials, depolarized the CM. Ondansetron blocked the preceding hyperpolarization associated with a CMMC. Spontaneous CMMCs and CMMCs evoked by spritzing 5-HT (10 and 100 μM) or nerve stimulation in preparations without the mucosa were blocked by SB 258719 or SB 269970 (1–5 μM; 5-HT7antagonists). Both NAN-190 and (S)-WAY100135 (1–5 μM; 5-HT1Aantagonists) blocked spontaneous CMMCs and neurally evoked CMMCs in preparations without the mucosa. Both NAN-190 and (S)-WAY100135 caused an atropine-sensitive depolarization of the CM. The precursor of 5-HT, 5-hydroxytryptophan (5-HTP) (10 μM), and 5-carboxamidotryptamine (5-CT) (5 μM; 5-HT1/5/7agonist) increased the frequency of spontaneous CMMCs. 5-HTP and 5-CT also induced CMMCs in preparations with and without the mucosa, which were blocked by SB 258719. 5-HT1A, 5-HT3, and 5-HT7receptors, most likely on Dogiel Type II/AH neurons, are important in initiating, generating, and propagating the CMMC. Tonic inhibition of the CM appears to be driven by ongoing activity in descending serotonergic interneurons; by activating 5-HT7receptors on AH neurons these interneurons also contribute to the generation of the CMMC.
Preventing increased blood pressure in the obese Zucker rat improves severity of stroke
Authors: Osmond Jessica M. , Mintz James D. , Stepp David W.
Published: April 2010

Obesity is a risk factor for stroke, but the determinants of increased stroke risk in obesity are unknown. We have previously reported that obese Zucker rats (OZRs) have a worse stroke outcome and display evidence of remodeling of the middle cerebral artery (MCA), in parallel with hypertension, compared with lean controls. This study tested the hypothesis that hypertension is an essential determinant of cerebral vascular remodeling and increased stroke damage in OZRs. Blood pressure was measured by telemetery in lean and obese rats with and without hydrochlorthiazide (HCT; 2 mg·kg−1·day−1) from 8 to 15 wk of age. A separate group of rats was also chronically fed a low-sodium (LS) diet. Vessel structure was assessed in isolated, pressurized MCAs. Cerebral ischemia was induced for 60 min using an intralumenal suture technique, followed by 24 h of reperfusion. HCT treatment effectively prevented the increase in blood pressure in obese rats; however, the LS diet did not lower pressure. Importantly, infarct size was normalized by HCT after ischemia-reperfusion injury. Additionally, HCT improved the changes in MCA structure observed in untreated OZRs. There were no benefits of the LS diet on stroke injury or vessel structure. These results indicate that increased pressure is essential for driving the changes in infarct size in OZRs.
Plasma biomarker profiles in acute exacerbation of idiopathic pulmonary fibrosis
Authors: Collard Harold R. , Calfee Carolyn S. , Wolters Paul J. , Song Jin Woo , Hong Sang-Bum , Brady Sandra , Ishizaka Akitoshi , Jones Kirk D. , King Talmadge E. , Matthay Michael A. , Kim Dong Soon
Published: April 2010

Little is known about the pathobiology of acute exacerbation of idiopathic pulmonary fibrosis (IPF), a condition that shares clinical and histopathological features with acute lung injury. Plasma biomarkers have been well studied in acute lung injury and have provided insight into the underlying disease mechanism. The objective of this study was to determine the plasma biomarker profile of acute exacerbation of IPF and compare this profile with that of stable IPF and acute lung injury. Plasma was collected from patients with stable IPF, acute exacerbation of IPF, and acute lung injury for measurement of biomarkers of cellular activity/injury (receptor for advanced glycation endproducts, surfactant protein D, KL-6, von Willebrand factor), systemic inflammation (IL-6), and coagulation/fibrinolysis (protein C, thrombomodulin, plasminogen activator inhibitor-1). Plasma from patients with acute exacerbation of IPF showed significant elevations in markers of type II alveolar epithelial cell injury and/or proliferation, endothelial cell injury, and coagulation. This profile differed from the biomarker profile in patients with acute lung injury. These findings support the hypothesis that type II alveolar epithelial cells are centrally involved in the pathobiology of acute exacerbation of IPF. Furthermore, they suggest that acute exacerbation of IPF has a distinct plasma biomarker profile from that of acute lung injury.